Full text of "Knowledge. v. 1-40; Nov. 1881-Dec. 1917"

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K>.Vi':'t.MV'i:A:'.

^'-

AV.

ILLUSTRATED

SCIENTIFIC NEWS

Conducted by MAJOR B. BADEN-POWELL and E. S. GREW, M.A.

'Let Knowledge grow from more to more"

— Tennyson.

Volume II. (new series).

JANUARY TO DECEMBER,
1905.

london :

KNOWLEDGE OFFICE, 27, CHANCERY LANE, W.C.

^All RiffJils Reserved.]

_^^

London :
King, Sell .S: Oliunc, Ltd., 27, Chancery Lane, W.C.

KNOWLEDGE & SCIENTIFIC NEWS.

INDEX

A PAGE

Abnormal Foliage of Sycamore ... ... -65

Absorption, Lines of Water \'apoiir ... ... 292

Acceleronieter, Pendulum ... ... ... 229

Accumulators, Solid Electrolytis for ... ... 39

Acetylene as an Explosive ... ... ... 90. 204

Action of Wood on Photographic Plates 119, 148, 235
,, ,, Light upon Glass ... ... ... 158

"Ad Infinitum" ... ... ... ... ... 74

Aflalo, F. G., on W'ord " Common "... . . 52

Agriculture, Scientific ... ... ... ... 151

Air in Crowded Rooms, the Physiological

Action of
Airships, Progress with in 1904 .. ...

Algol Variables

Alpha Stream, The

Alimiinium, Absorption of Mercury Vapour by

,, a New Process for Welding

Anglesey, a Ruined Beach in ...
Animals, Coloration of ...
Antimony in Rubber Rings
Apes, Man-like

Arsenic Crystals, The I'lashing of
.\stronomy, Notes on

,, Books on

Atom, The Structure of the
Aurora of November i? ...

206
26

145

148, 198

- 39

134

each month
... 18, 41

74
293

Bacon, The Late Rev. J. M

Bacon, The Late Rev. |. M., on Seeing

Beneath the Waves ...
Bacteriology, Book on ...

Baden-Powell, Major, on Progress with Air-
ships ...
Barometer, The " Piesmic "
fJastian, Dr. H. C, on the Simplest Kind of

Protoplasm ...
Beach, A Raised, in Anglesey ... ... ...148,

Beilby, Mr. G. T

Benham, C. E., on the Induction Pump

Bequests of Mr. Frank McClean

Big Game Extermination

Bio-chemistry of Muscle and Nerve, Book on...

Birds, See Ornithological Notes ... each m

,, of Russian Lapland, Review of Book on

,, Migration of

Bird-like Flying Machine, A

Black Currant Gall Mite

Blanford, The Late Dr. W. T

Blondlot, N-rays of ... ... ... ...218,

Botanical Notes ... ... ... ... 14, ^7

Botan}', Book on ...

Boulenger, Mr. G. A.

Breeding of Flamingo and of Pterochs Exustus

Brightness, Stellar

Britain, How it Became an Island

British Association Meeting, 1905 ... 54, 165,

98
40

199
198
166
196

190

onth

87
120

234
208
242

, 63
66
167

15
81

75
etc.

Bruce, Col.

Butterflies, Dimorphic Mimicry Among

Calcium Liyht, Sun in ...
Cameras, Small, in Eclipse Work

,, for Travellers
Carnegie, Mr., Gift of Diplodocus to Nation
Catalogue of Scientific Literature
Celestial Catastrophe, A Possible, by J. E. Gore
Celluloid, Rendering Incombustible ...
Chemical Re-actions, Tele-activity of ...
Chestnut Flour of Corsica
Gierke, Miss A., on Modern Cosmogonies

Coal ^ ...

Coffee without Caffeine ...
Coloration in Mammals and Birds
Comet, Return of Tempel's

,, Discovery of a New ...13, 63, 108,

"Common," as Term in Natural History
Comparascope, The " Ashe-Finlayson "
Conservation of Mass, The
Copper Treatment of Water
Corona, Photograph of, in Daylight ...
Corpuscles, Emission of, in Dark
Cosmogonies, Modern, Miss A. Gierke
Craniology of the People of Scotland ...
Creation of Species
Crommelin, Mr. A. C. D., on Satellites t

Jupiter
Crossley, Death of Mr. Edward
Crossley, Reflector, The ...
Cunnintrham, Rev. \\'. ...

Dark Stars

Darwin, Prof. G. H

Daylight, Visibility of Planets in

Deaths from Snake Bites

Denning, Mr. W. F., on Jupiter

Desmids, Cleaning

Diamonds, New Experiments on the Making o

,, In South Africa

,, The Cullinan

Dimorphic Mimicry among Butterflies ...
Dinosaur ...

, , The Carnegie ...

,, The Smallest British

,, An Armoured ...

Diplodocus Carnegii

,, ,, Age of

PAGE

171
I' 239

224.

185
'34
100
261

67
220
^75

95
15S
302

293
13

205
83

281

126

''4
108

304
95

237

2^9

165

204

291

235
132

174

134
160

2-:iO
128
159

Ears of Fishes

Earth's Heat caused by Radium
,, Affe

KNOWLEDGE cS: SCIENTIFIC NEWS.

Earthquake in England ...

,, Where to be Safe From ...

Eclipse, Total, of August 30, 45. 71, 233, 246, 271,
Expedition ... ... ..■ •■■ 37i

,, Polarisation Observations during the

,, Photography

,, Shadow Bands ■■■271,

Eggs of the Knot
Electric Spark Photograph ... ... .•• 32

Electrical Experiment ...

Electrographs ■ • 3~

Electrolytis for Accumulators, Solid ...

Electrotyping, Dr. F. Molhvo Perkin -9,

Equation of Time Theory

Eoliths

Erosion in Freshwater Bay

Ether Drift ' 160,

Evolution, Specific Scrum Test as Proof of ...
Explosive, .\cetylcne as an ... ... ... go,

Extinct Reptile I-'auna ... .■■ ...178,

Animals, Book on ... ... ...

244
299

271

274
207

, 61
255

, 61

39
149

251
252
206
255
132
204
208
274

Fibrous Constituents of Paper ... ... 42, 68, 9-:

Fire Sticks, Queensland ... ... ... ... 58

Fishes, Ears of ... ... ... ... ... 59

Flamingoes ... ... ... ... ... 15, 38

Flashing of Arsenic Crj'stals ... ... ... 203

Flat Fish, Migration of ... ... ... ... 151

Flint Implements Found by Accident ...

Florence, The Great Gnomon at

Flour, Electric Bleaching of

Flying Machine, A Bird-like ...

Fog, London ... ... ... ... ... ,

Footprints, The Connecticut
Forecasting Seasons

Forsyth, Prof. A. R

Fossil Reptiles

,, Marmot Burrows

,, Trees in Glasgow
Foxes, Black

Gas, Natural, in America

'- -'-hein. The

David

\rtion of Light Upon

GU..v->> Ibis

Glycerine as a Mounting ^fcdium

Gnomon, The Great, at Florence

Gold .Mines in .South Africa ... 1

Gore, J. E., on -Stellar Brightness

Gore, J. E., on a Possible Celestial

Catastrophe ...
Gorilla at the Zoo
Gratings, Thorp ...
Great Red Spot on Jupit. r
Grcenwich-I'aris Longituflc
Gum Disca.sc of Sugar Cane

219

287
8f>
120
204
278
80
166
304
'34
2 70

182
'.S8
48
2.S8
287

I (JO

2C>t

Mnddon, Dr. A. C

Halm, Dr., on Regularities in Spcclr;i
Hay Fever, An .Anti-.Scrum for ...
Health Resort, -South Africa as a

iCxj
277

2.S4
1^9

Heat, The Earth's, Cau.sed by Radium
Heath, T. E., on " A Xc-w \"iew of the Stars
,, ,, on " Our Stellar Universe "

Heredity, by }. C. Shenstone

Herschel Memorial ...

Hutchinson, F. W. H., on Flying Machines .
Hvdrogen Peroxide, Radiation from ...

IbLs, The Glossy ...
Incombustible, Rendering Celluloid
Influenza and the Weather
Induction Experiment, .V Curious

,, Pump ...

Ink, Symphatetic ...
Interruptor, A New
Insects, Mimicry Among
Iron Lightning Conductors

54
141
. 49

29
120
206

48
07
264
102
196
302
160
239
"3

lebb, -Sir R. C

'7'

Jupiter, Great Red -Spot on

'3. 37.

291

Sixth Satellite of

37.

<'3, '57.

21,7

-Seventh Satellite of

«5.

'-57. 237,

253

,, Great South Tropica

Spot

...224,

291

Kagu, The IIal)ils
Knot, 1-ggs of the

.f the

'.59

146,

Lancelet, The Pelagic
Lebaudy .\irship ...
Life, The X.iture of

,, Duration of Among Birds
Light Energy, Review of Book on
Lightning Conductors, Iron
Literature, Catalogue of -Scientific
Lockyer, Dr. W. J. -S., on Our -Sun and

Weather .. ... (

,, ,, on Thorp (iratings

in Eclip'^e Woik

,, ,, on the .Sun in

Calcium L'ght ... ly i
Longitude, Greenwich-Paris
London l""og ... ... ... ... ... 38,

" Lf)ndon's Transformation" ... ... •••283,

Luminous -Shrimps

Magnetic -Survey of North Pacific
Magnetism, Terrestrial, Book on
Mammals that Carry Their Voung
M.'iinmals, Coloration in
,, Origin of

,, Lower Jaw ol

Mars, North Polar Cap of

,, .S«-asonrd Changes on .

,, Photogr.iphy of C.'inals on ... 158,

Martin, Geoffrey, on the Nature of Life 125,
Mass, The Con.servation of
McClean, -Scientific Bequests of Mr. I''rank ..
Medals, Royal Society ...

204,
14G,

'-14

194

303

"3
100

'. 33
117

2'5

14
204

'34

227

J05

293

208

230

2.53

'3'

205

194

126

KNOWLEDGE & SCIENTIFIC NEWS.

Mercury, Spectroscopic Observations of ... 205

Mercury Vapour, Absorption by Aluminium ... 77

,, ,, Prevention of Poisoning by 158

Meteorite, of Willamette ... ... .. 19S

Meteors, November ... ... ... . 27^

Meteorological Notes ... ... ... .. 38

,, Instruments, Exhibition of ... 47

Meteorology, Practical, Rainfall ... ... 221

Micro-Photographs ... ... ... ... 20, 280

Microscope, Watson's Bactil ... ... ... 281

Miers, Prof. H. A. 167

Migration of Flat Fish ... ... ... ... 151

Mimicry Among In.sects ... ... ... ... 239

Mineral, A New, Thorianite ... ... ... 228

Mines, Royal School of ... ... ... .. 23(1

Mite, the Black Currant Gall 234

Mitchell, C. A., on Action of W'ood on Photo-
graphic Plates ... ... ... ... 119

Modern Cosmogonies, Miss A. Clerke ... 24, 9:;

Monoclea Forstori ... ... ... ... 78

Moon, Comparison of Features with Earth .. 13

,, Review of Mr. Pickering's Book on the 18

,, Eclipses of ... ... ... ... 44

,, Secular and Seasonal Changes on the ... 8:;

Mount Wilson Solar Ol3,ser\atory ... ... 131

Museum, the South African ... ... ... 183

Nation '.s Latest .Acquisition, The ... ... 128

Natural Gas in America ... ... ... ... 73

,, ,, The Utilization of

Natural History of South Africa
Nature of Life, The, by G. Martin
Niagara's Horse-Power ...
N-ray Experiments

,, ' of Blondlot

302

176

125, 146, T94

-54

...218, 242

Observation of the Total Eclipse . ... 233

Observatory, The New Solar, on Mount Wilson 131

,, The Royal, at the Cape ... .. 182

Optical Convention ... ... ... ... 102

Orion Nebula, Monochromatic Photographs of 227

Ornithological Congress ... ... .. 5, 201

,, Notes ... ... ... each month

Our Sun and Weather ... ... ... C:i, .33

Ozone, Formation of by Ultra-\iolet Light ... 275

Paper, Fibrous Constituents of ... 42, 68,

"Patent," The Word ... ... ... ...150,

Pendulum Accelerometer ... ... r..

Penguin, The Emperor ...

Perkin, Dr. F. Molhvo, on Elsctrotvping ... 9,

,, ,, ,, on Sugar

Photograph of Electric Spark ...

,, Monochromatic, of Orion NebuLi

Photography, Abroad

Photography, Pure and .\pplied, by Mr. Chap-
man Jones ' ... each mc

Photographic Films, Stripping of

,, Action of Hydrogen Peroxide ...

,, Plates, Action of Wood upon

119, 14S,
Photo-Micrography ... ... ... ...280

226
229
65
149
267

i«5
nth

308

Physics, The Methods of

Pickering, W. H., Book on the Moon

Piesmic Barometer

Pig, A Giant

Pinatype Photographs

Pinnacle, A Sliding

Polarisation Ob.servations during Eclip.sc

" Potcntia " Organization

Protoplasm, The Simplest Kind of, by Dr.

Bastian
Poisoning by Mercury \'apour, Pre\cntion of
Porter, Alfred W., on the Conservation of Mass
Pressure, Radiation
Preser\ative for Animal Products
Pycraft, W. P., Ornithological Notes on each
,, ,, The Nation's Latest Acquisi-

tion

230
18

256
279
290

199

I2()

164

inonlh
128

Oueensland Fire Sticks

Races of South iMrica

Raccoon Dog

Radiation from Hydrogen Peroxide

Radiation Pressure

Radium, Apparition

,, The Cause of the Earth's Heat

,. Formation of, from L'ranium

,, Particles Emitted by ...

Radio-active Substances in Natural Waters

Radio-activity, Some New Discoveries in
,, and Cultivation of Plants

Radiograph, by Thorianite

Rain Drops, Solidified ...

Rainfall

Raised Beach in Anglesey

Rare Living Animals in Londt)n

Reptile Fauna, Extinct ...
,, Mysterious

Royal Observatory at the Cape

Royal Society, Medals Awarded by . . .

Rubber Rings, Antimony in

172

«4
100

15-
270

bi
228
229

86
250

228

221

48,

ig8

48,

130

7«.

208

3o,S

182

228

Salamanders, The Origin of
Satellites of Jupiter 37, 63, 85, 157

,, ,, Saturn

.Saturn, Tenth Satellite of
Scent, of Sitting Birds ...

,, What is it?

.Sclater, Dr. P. L. , on the Glossy Ibis
,, ,, ,, on Scoresby's Gull

.Scoresby's Gull

Scott-Moncrieff, Sir C. ...

Seasons, Forecasting

.Seaweeds ...

.Sedimentary Formations, Thickness

Earth's
Seeing Beneath the W'aves
Seismoscope.s
Shackleton, W., on Total Eclipse

,, ,, on Aurora of Nov. 15

„ ,, on the Face of the Sky

^37.
•131.
•131.

208

^S3
i5«
158
207
266

48
130
130
1(19

80
248

276

295

■■■ 4.S, 7'

293

each month

. 202, 225,
of the

KNOWLEDGE \- SCIENTIFIC NEWS.

13. 37. 224,
103, 128, 150, 184, 200,

Shadow Bands, Eclipse ...

Shaler, Prof., Comparison of liarth and Moon

Shenstone, J. C, on Heredity 17

Sliding Pinnacle, A

Solar Constant, New Determination of

,, Spectrum, Helium Absorption in
Soot, Composition of

South Africa ... .-■ .■■ ■■■ •••i7->

South African Association for the .Advance-
ment of Science
Speedof Animals ...
Spectra, Regularities in
Spectroscopy, Book on
Spiders, Venom of
Spot, Great, on Jupiter
Squirrels
Star Maps ... ... 80,

,, A Probable New

,, Streams
Stars, A New \'ie\v of, by T. E. Heath

,. Dark

Stellar Brightness and Density, J. E. Ciore

,, Universe, Our, T. E. Heath
Submerged Coa.-t Eines ...
Sugar, Dr. F. M. Perkin on ...
Sun, Variatit)n in Figure of the

,, Our, and Weather, Dr. Lockyer

,, Photograph of

,, Rotation of ...

in Calcium Light, Dr. Lockyer 191,

Sunspot Spectra ...

,, Recent Large ... ... ... ... 63,

Sycamore Seedling, .'\bnormal ...

Tantalum, Preparation of Pure ...

Tarn.s of Ticino ...

" Tele-activity " of Chemical Re-actions

Telegraphy, Wireless

Tcmpel's Comet, Return of

Thorianite, a New Mineral

Thorp Gratings in Eclipse Work

Tobacco, Consumption of

Tortoise, Remains of a British ...

Total Eclipse of 1905 37, 45, 71, 233, 246-7, 271-4,

Ultra-xioltt Light, I-'ormatinn of Ozone by ...

. 49
290

85
157
254
etc.

1 82
"5
-77
256
298
291
278
224

54
249

81
141
30"?
267

275
> 33
297

85
215

14
297
265

206

220

13
228

117

299

275

L'nfolding of Wings of Insects ...
L'niverse, Our Stellar

\'icloria Falls

\'isibility of Planets in Daylight

,, Limits of, in the Microscope

\'enom of Spiders

Wager, .Mr. 11. W. T

Water Finding with the " Divining Roil

,, Copper Treatment of ...

,, \'apour, .Xbsorption Lines of ...
Waves, Seeing Beneath ...
Webb, W. M., on the Ears of Fishes ...
Well Boring at Holborn ...

Whales in \'.W. Atlantic

Wharton, Sir W. J. L

\\'illaniette, The Great Meteorite of ...
Williams, Mr. Stanley, on the Great Red Spo

on Jupiter
Wimshurst Machine, .\n Iniprox cnicnt in the ..
Wind, Velocity of the ...
Wings of In.sects, Unfolding of
Wireless Telegraphy

Wood, Action of, on Photographic Plates 119,
Writing, Detected by Photography

i4«.

F.\C.E
78

'4'

iSi
204

258
298

•7'

292

S()

i()

i()8

198

.^7
90
38
78
80

23.^
162

X-rays, Book on

Young, Mammals that Carry IJK-ir

Zambesi, The, and Its Sights
Zimbabwe, The Great ...
Zodiacal Light, The
Zoological Gardens, Cairo

180

186-8

203, 292

244

"X^^K^

KNOWLEDGE & SCIENTIFIC NEWS.

vii,.

ILLUSTRATIONS.

(Titles ill heavy type are those 0/ whole page Plates.

Airships

Aluminium, Welding

Bacon, Late Rev. J. M

Baldwin's Airship
Beach, A Raised ...
Benbow's Airship
Bird-like Flying Machine
Bird's Wing, Trajectory of
Boulenger, Mr. G. A., Portrait

Beilhy, Mr. G. T., Portrait

Britain, How It Became an Island, Map
Bruce, Col., Portrait
Butterflies, Mimicry Among

Cameras in Eclipse Work

Chevron Pattern in Wall, Zimbabwe . .

Crossley Reflector, The ...

CuUinan Diamond, The ...

Cunningham, Rev. W., Portrait

Darwin, Prof. C. H., Portrait

Dissecting Stand, Home Made ..
Diamond, The Cullinan ...
Diplodocus Carncgii

Ears of Fishes

Eclipse, Total ... 47, 73, 117, 246, 27

,, of INIoon
Electric Spark Photograph . . 61,

Electrotyping

Fire Sticks

Fishes' Ears

Fishes, Migration of

Florence, Great Gnomon at

Fo.ssil Trees

Flying Machine, A Bird-like

Forsyth, Prof. A. R., Portrait

fiill, Sir David, Portrait
Glossy Ibis

Gnomon, Great, at Florence
Gull, Scoresby's ...

Haddon, Dr. A. C, Portrait

Ibis, Glossy

Insects, Mimicry Among

Insects' W'ings, Unfolding of ...

Jcbb, Sir R., Portrait

Lebaudy Airship ...

Mammals that Carry Their \'oung
Meteorite, The Great, of W^illameth ..,
Meteors, Xovembcr, Chart of . .

PAGE

27, 28
14.S

14S
-7

!2-I24
121
167

77
171
i. 241
iiS
188
-,01

i^S

129

299

214

facing 32

5c>

I :;i

287-9

276

122-124

166

182

48
287-9

130

169

I, 240

T7I
28

10:5-107

^ 1 98

278

Microscope, Watson's Bactil

Portable

,, Detecting \Vriting by the

Miers, Prof. H. A., Portrait ..."
Monoclea Forsteri

Paper, Fibrous Constituents of

Photographic Plates, Action of Wood on

Photo-visual Lens, Taylor

Pinnacle, A Sliding

Plaice, Marked

Prominences on Sun

Protoplasm, The .Simplest Kind of

Queensland Fire .Sticks ...

Raccoon Dog, A White ...

Radio-activity

Radiograph by Thorianite

Rain Guage, Snowdon Pattern ...

Raised Beach in Anglesey, A . .

Scott-MoncriefT, .Sir C, Portrait

Scoresby's Gull ...

.Seaweeds

.Seismoscopes

.Siderostat

Sliding Pinnacle, A

.Slit for Photographing Sun

.Snow Crystals

-Spain, Map of, with Track of Eclip.se ...

Stellar Universe, Our

Sun, with Spots

,, in Calcium Light ...

,, Photograph of, in One Colour

„ Total Eclipse of

Sugar Extraction

Sycamore .Seedling, Abnormal ...

Taylor Photo-visual Lens
Telescope, Crossley Reflector ...
Thorianite, .Action of on Photographic Plate
Total Eclipse of the Sun . . . facing 246
Transit of the Earth as .Seen from Mars

LTnfolding of Wings of Insects ...

Victoria Falls

Vertical Illuminator

Wager, Mr. H. W. T., Portrait

Waves, Seeing Beneath ...

Welding Aluminium

Wharton, Sir W. J., Portrait

Wood, Action of on Photographic Plates

Zambesi Railway Bridge

Zimbabwe, Elliptical Temple at ..187, iJ

6
19

246,

281
69
162
167
78
92
120
191
290
LSI

.S8
84

148

169

130

225, 248

■ ■ 295-7

192

290

192

223

143

facing 297

3, 215-217

2712, 299

268-9

265

191
301
228
271-2, 299
116
78
iSi

171
99
145
168
120
180

STAR MAPS

No. I. Northern Polar Stars

,, 2. Pegasus, Andromeda, and Pisces

,, 3. Cetus, Eridanus

,, 4. Perseus, Auriga, and Taurus

,, 6. Leo, Cancer

,, 12. South Polar Region

Opp. page 104

128

150

.. .. 224

,. ,, 200

184

KDOdiledge & SeleDtifie flems

A MONTHLY JOURNAL OF SCIENCE.

Conducted by MAJOR B. BADEN-POWELL and E. S. GREW, M.A.

Vol. II. No. i.

[new series.]

JANUARY, 1905.

r Entered at -1
LStationers' Hall. J

SIXPENCE.

CONTENTS.-^See Page VII.

Dimorphic Mimicry
©Lmong Bvitterflies.

Perhaps the most striking instances of true mimicry
are those which may be described as dimorphic. Not
infrequently, but for reasons which are generally very
obscure, the sexes of a butterfly differ so widely in
colours and markings that the casual observer would
certainly take them for representatives of distinct

species. And when such a difference exists between
the male and female of a well-protected butterfly which
is a prototype for mimicry the male and female of the
mimicking species are sometimes seen to have each
followed out, almost line for line, the colour charac-
teristics distinguishing the sexes of the distasteful
insect. This is well shown in the case of Euplcea
linnet and Elymnias leucocyma from Assam. The males

of both these species have shining blue fore-wings,
spotted with white; the fore-wings of the females have
a circumscribed blue area, spotted with white, while

(

5?rir V- «iiM

^Wi

Bahora aspasia c? and ?- Ex Sumatr

KNOWLEDGE & SCIENTIFIC NEWS.

[Jan., 1905.

their hind wings are brown with pale stripes. Yet the
species belong to entirely different groups, and are
related by no closer bond than that of mimicry. The
Etipltra is the evil-tasting prototype. The Elyitiiiias
belongs to a group of poorly-protected butterflies allied
to the Salyrida, or " Browns."

.Again, instances occur in which the female of a
species is mimetic, while the male is either non-mimetic
or else resembles a prototype quite distinct from that
followed by its mate. In the case of Eroiiia vaUcria
(from Sumatra, Borneo, etc.), the male may, perhaps,
be regarded as an imperfect mimic of the strined
S()ecies, a Danais, so common in these islands. The
female is a very close mimic of Balwra aspasia, frcm

F.r,mia raltrrin i and

Ex Sumatra. (Compare fen

H. aitimtiin.)

the female of which the inexperienced observer would
be unable to separate it.

Sometimes a single species has two or more distinct
forms of the female, each of which is coloured in
mimicry of a separate evil-tasting species. In illustra-
tion of this, the case of Papilio pammon, a species
havi.nfj a wide r.inge in the liiast, may be cited. The
male of (his butterfly is black, the fore-wings having
a marginal row of white spots; the hind wings having
a curved, transverse band of white, divided into spots
by the nervures. There is a form of female almost
exactly like the male, but it is somewhat rare. The
common forms of female are entirely dissimilar to
their mates, and were described as different species by
the old naturalists. That which was called P. pnlxtes
has a large white spot, broken by nervures, in the
middle of each hind wing, and a' row of large red
m.nrginal spots. The dark brown fore-wings are
striped with a pale colour. The other common form
of P. pammon female, described originally as
P. rnmnlm, has extensive red markings on the' hind

wings, and no white spot. Its fore-wings are crossed
with two broken bands of white.

an i and ? (form like tf).

These two forms of female mimic respectively two
iistinct spncies of butterfly, belonging to another

PajnV.ii nHiloliuhr. Pn))UUi immmnn ? {imliilf form).

section of the great Papilw genus, which appear to be
well-protected insects. The pnlvtcs variety of P. pammon

Jan., 1905]

KNOWLEDGE & SCIENTIFIC NEWS.

is curiously like P. aristolache ; the roniulus form is an
equally close mimic of P. hector.

These wide differences existing between the sexes
of a mimicking species seem at first very difficult to
understand. It has been suggested that the males,
for some reason, are better able to protect themselves
than are the females, and do not, therefore, need the
protection of a mimetic likeness to a warningly coloured
type. In some cases the males certainly seem stronger
on the wing, and better able to escape from danger by
flight; while it is obvious that the females, when de-
positing their eggs upon vegetation, would run more
risk of being attacked by birds and other insectivorous
creatures than their mates, who are free from pre-
occupations likely to detract from their alertness.

The question as to how such wide differences be-
tween the sexes of one species came to be seems, at
first, a very perplexing one, especially in cases where
two or more mimicking varieties of the female exist.
We know that living creatures often exhibit a strong
tendency to vary, but these several well-marked forms
of one species seem to be something more than the
outcome of mere "sports."

It is possible — at least, in some degree — to show
how they have been produced and established. There
are two common butterflies of the family A^ymphalidce,
known respectively as Hypoliniiias misippiis and
H. holina. These species have their headquarters in
India, but they have a wide range in the Eastern
Hemisphere. They are closely related, and the males
are very similar — both having blackish wings, with

PnpiUo heelm: Papilio pnmnwn ? {miiiihis iorm).

central areas of white beautifully tinted with shining
purple. The females of both species are curiously
variable, and are well worth a careful study by those
seeking to comprehend the theory of mimicry. Taking
first H. misippus, we find that no female at all like the

male in appearance is known to exist. The common
form of female is that shown in the accompanying
photograph. It is bright tawny, bordered with black,
and has a conspicuous band of white in the fore-wing.
In this it is seen to be a wonderfully accurate copy of

DfinnU chrysippus. Ht/poHmna^ misippti-f ?. Htipolimtian misippus tf.

that common and much-mimicked Eastern butterfly,
Danais chrysippus. This insect [D. chrysippus) is
common all over Africa and Southern Asia, and there
are a number of closely allied forms — whether constant
local varieties or actual species is not definitely
known. These forms vary a good deal in colour and
marking. For instance, in D. alcippus the hind wings
are almost entirely white; in D. kliigi, all the wings are
tawny, with black edges, and there are no white bands
in the fore-wings. The range of H. misippus is very
similar to that of D. chrysippus and its several forms,
and wherever a marked difference is seen in the ap-
pearance of the latter, it is found to be reproduced
upon the wings of the mimicking females of the former,
usually in a strikingly close manner. But though the
females vary in different districts, the colouring of the
males is identical in each locality-

These facts — the extraordinary difference between
the sexes, the various forms of the female, none of
which are in the least like the males — are very sur-
prising; but in the case of the allied H. holina we find,
in measure, a key to the mystery. The females of this
butterfly vary in a much more erratic manner than do
those of H. misippus, albeit none of them has attained
to such striking mimicry. There is a form (shown in
the accompanying photograph) which is an imperfect
mimic of the common evil-tasting butterfly, Euphva
iore : there are also dozens of other forms, all ex-
hibiting some marked difference, but few showing any
tendency towards a mimetic likeness. The group of

KNOWLEDGE & SCIENTIFIC NEWS.

(Jan.. 1905.

females showing the gradual growth of the tawny
colour, however, is interesting. The colour (which is
quite unknown on the wings of the male) makes its

appearance as a small spot, and may be traced Iriini
one specimen to another until it is seen to form a large
suffusion in the wing-area. Such specimens go far to

llffnllmw iMtiKa « 1. 'L'pp«rone like malt-.

bridge over the gap between the //. muippus male and
its perfectly mimetic, tawny females; for these tawny
blotched females of TJ. bolina seem to show a definite
variation in the direction of the Danaii chrysippus pro-
totype. It is conceivable that eventually, through the

agency of natural selection, this dawning mimetic like-
ness may be perfected and established, as it appears to
have been in the case of H. vtisippus.

It is impossible to suggest a reason to account for
the different courses of natural selection in the case of
species so closely related. The fact remains, however,
that whereas the colour specialisation of H. misippus ap-
pears to be fairly complete, that of H. bolma is still in
an elementary stage. The females of H. mhipptis
differ both from the male form and from one another,
but always in the direction of some well-protected pro-
totype; moreover, there are no intermediate forms.
The females of H. bolina, on the other hand, vary from
specimens that are almost like the males through an
extensive range of closelv connected forms, very few of
which approach anv existing warniiiglv-coloured proto-

Although the mimicking Hypolimiias butterflies are
often instanced as cases of true or Batesian mimicry,
some authors consider them to be typical of what is
known as Miillerian mimicrv, in which both the tvpe

and the copy arc well-protected insects, deriving en-
hinced benefit from their mutual likeness. The theory
of convergent mimicry, as suggested by Professor
Miillcr, will be described in a subsequent article. But
the question as to which section of mimicry the
Hypolimnas butterflies rightly belong in no way affects
the interest attached to their colour development as de-
scribed above.

.An instance of the manner in which butterflies be-
longing to widely distinct families develop a close
external likeness one to the other, because of their
mimicry of a common distasteful type, is seen in the
annexed photographs. The prototype is Amaurh
dominicanns from South Africa. This is mimicked by
one form of Papilto cciica female, which, it is seen,
differs from the male not only in colour and marking,
but also in the complete loss of the long " tails " of
the hind wings. Then the Nymphaline butterfly,
Euralia (JJ ypolimnin) anthcdon, in both sexes, is a very
perfect mimic of the Amauris.

There is also, in Cape Colony, another form of
Papilio cenea female, which is a striking mimic of

Jan., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

another butterfly of the evil-tasting group (Amauris
cchcria), which is black blotches and spotted with rather
dusky yellow. This form is very like another species

Pninl I) cui'ii rC. Ex S. Africa.

of Etiralia, which also mimics the A. echeria. Finally,
there is a third form of P. cenea female, tawny in
colour, marked in black and white in imitation ol
Danais chrysippm ; and, as we have seen, the females
of Hypolimnas misippus are very perfect mimics of the
same species.

Amaurw dominicanm. Papilio cinea ? . Ex S. Africa

In regard to the multi-form females of Papilio cenea,
it should be pointed out that there exist in Madagascar
and Abyssinia closely allied species, the females of
which differ very little from the males. Not only have
they the same pale yellow and black colouring, but the
hind wings preserve the characteristic tails. There is,
however, a prominent black bar on the costal margin
of the female fore-wing; and it is presumed that this
represents the commencement of the darkening, which,
in the case of the allied mimetic females, has suffused
so large a portion of the wing area,

The question as to why the females of species closely
related to others which are very perfect mimics should
have retained tii:_-ir ;m(-ostral form is difficult to answer

EiiiiiUit(tiillieih,n S and 1. Ex S. Africa.

satisfactorily. In the absence of contradictory evi-
dence, however, it is quite admissible to assume that
the life histories of these non-mimetic species have been
fraught with less hardship and persecution than fell to
the lot of those which have gained the protection of
mimicry. In the case of Papilio nuriones, this view is
certainly plausible, and is adopted by Professor
Poulton. " It requires a very slight exercise of the
imagination," he says, " to picture the steps by which
these marvellous changes have been produced; for
here the new forms have arisen at so recent a date
that many of the intermediate stages can still be seen,
while the parent form has been preserved unchanged
in a friendly land, where the keen struggle of con-
tinental areas is unknown."

The Fourth Interna.tional Ornithological
Congress.

The Fourth International Congress of Ornithologists will be
held, as arranged at the previous meeting at Paris in igoo, in
London this year, under the presidency of Dr. R. Bowdler
Sharpe, the head of the Ornithological Department of the
British Museum. It will assemble at the Imperial Institute,
South Kensington, on Monday, June 12, and sit until the end
of the week, during which, besides the ordinary business, it is
proposed that evening meetings and short excursions shall
take place. Longer excursions will be made after the close of
the meeting. An Organizing Committee has been formed to
make the necessary arrangements.

The Secretaries 'to the Congress will be Dr. Ernest Harterl,
of the Zoological Museum, Tring, and Mr. J. L. Bonhote, of
Ditton Hall, Cambridgeshire, to whom communications may
be addressed. The Treasurer will be Mr. C. E. Fagan, of the
Natural History Museum, South Kensington. It is hoped and
expected that many of the leading ornithologists from all part§
of the world will attend the Congress,

KNOWLEDGE & SCIENTIFIC NEWS.

[Jan., 1905.

Svin

Our
SLiid "Weather."

By William J. S. Lockver, M.A., Ph.D.

" The moon and the weather
May change together ;
But change of the moon
Does not change the weather.
If we'd no moon at all,
And that may seem strange,
We still should have weather
That's subject to change." — Notes and Queries.
There are many of us who would like to know whether
our ne.\t summer will be sunny and warm or our next
winter dry and cold, so that we might prepare for the
delights that could be enjoyed by such weather conditions.
That day is not however with us yet, and its delay in
coming is owing to many reasons, the chief among which
being that civilized nations were not so widely scattered
over the earth as they are now, and that consequently
meteorological records extending over a long period of
time do not exist in sufficient number to allow of a
complete discussion being made.

If we only had behind us one hundred years of good
meteorological observations made in the way that they
are to-day, and also an unbroken record of observations
of sun-spots and prominences, then we should be in a far
better position to tackle such meteorological problems as
are now lying before us unsolved.

Unfortunately one cannot go much further back than
about fifty years when discussing the great majority of
meteorological observations, for in many cases they are
either very sparse and broken, or it is not known with what
degree of accuracy they were made. In the case of solar
phenomena the investigator is still more restricted ; for,
although the observations of sun-spots have been made in
a more or less crude manner for a great number of years,
it was not till about the year 1830 that a systematic
method of observation was adopted ; further, the solar
prominences, important indicators of the sun's activity,
were only first recorded systematically in the year 187/.
The reader will therefore understand that before all these
difTerent phenomena can be correlated to enable long-
period forecasts to be successfully made, a greater period
of time than the one at present available is absolutely
necessary.

This is, however, no reason why attempts should not
now be made to find out whether these solar and terres-
trial changes are related to each other, and if possible to
point out how, from our present material, such a relation-
ship, if detected, can assist us in making at any rate
rough forecasts of approaching seasons.

It is generally acknowledged that we are children of
the sun, and life on this earth is only possible in conse-
quence of his presence. Our sun is, so to speak, the
fuel on which we are all dependent, and it is, therefore,
quite natural to look to him as the instigator of our
" weather." Now, our orange-shaped globe is surrounded
by the atmosphere. The sun from without pours his
rays down on the earth's surface and heats it, whether it
I)e water or land ; this heated land or water warms the
atmosphere in contact with it. and this warmed air,
which is now lighter than it was before, rises from the
surface and is replaced by the cooler and heavier air
flowing in at the bottom. In this way a current of air,
a wind, is set up. The land or water most heated in this
manner is that which lies in those regions over which the
sun during a year passes overhead, and the reader will

at once gather that this part of the world is that which
includes the equatorial regions. It is due to the heat-
ing of this region, coupled with the great cooling about
the terrestrial poles in consequence of the presence of ice
and snow, that the whole mechanism of the circulation
of the atmosphere is set in motion and maintained, and
" weather " is the ultimate result of this circulation.
Fortunately for us — but unfortunately for meteorologists
— the surface of the earth is not completely covered over
with water, but is studded here and there with great
stretches of land, so that an unequal heating of the atmo-
sphere round the equator takes place, and the directions
of the atmospheric currents the further the equator is
left behind, combined with the rotation of the earth,
become more complicated than they otherwise would be.'
To study the action of the sun on the earth to its
fullest extent it is therefore best to begin in the region
about the earth's equator where the solar action is
greatest ; and when this is completed, to trace this action,
which would probably be communicated by the air
currents, to the regions in higher latitudes.

Fiif. i.-The Sun. u<
.showJnff the spots
muximum.

about the time of sun.spot

It is well known not only in these hut in all other
latitudes that the " weather " is not the same every year.
Sometimes there is a great abundance of rain, sometimes
very little; one winter is very mild while another is very
cold. In fact each continent has its own little meteoro-
logical worries such as floods, droughts, fatnines, &c.
Thus India has just recovered from tlie most severe
famine ever known, while Australia is labouring from a
similar visitation. There seems little doubt that all these
conditions are produced by changes in intensity or direc-
tion, or both, of the main currents in our atmospiiere,
and since these conditions depend for the main part on
the distribution of atmospheric pressure, it is this element
which should receive the closest attention.

It has been stated above that the most likely cause of
these variations finds its origin in the sun, for, granting
a change in his heating powers, the strength of the
atmospheric currents, and consequently the atmospheric
pressure, would be accordingly altered.

The question therefore arises, Does the heating power
of the sun vary ? This is difficult to answer directly, al-
though from certain observations of his surface, to which

Jan., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

reference will now be made, the deduction is that great
heat variations do occur.

If the sun's disc be scanned from time to time, it will
be found that sometimes there are spots and some-
times there are none (fig. i). According to our
present knowledge these spots are produced by the
descent of comparatively cool matter from the higher
reaches of the solar atmosphere, so that the more spots

18/6 1877 1878 'l879

Fig

^e dark portion shows the variation in the £
1 the Sun from year to year for an eleven = i
three prominent outbursts in the year* 1870 and 1871

there are, the greater the quantity of matter descending.
Since this falling material is the result of previous up-
rushes of highly heated matter from the lower levels of
the sun's atmosphere, it stands to reason that this spot
phenomenon indicates great solar atmospheric disturb-
ance and therefore greater activity and consequently
more intense heating capacity. Thus we arrive at the
conclusion that the greater the number of spots, the
greater the solar activity and therefore the hotter the sun.
Now there is a decided periodicity in spot activity.
For some years only a few spots become visible, while
a little later they become more numerous until a maxi-
mum is reached, after which they begin to dwindle again
in numbers until the succeeding minimum is attained
when the sun remains spotless for months together. The
accompanying diagram (fig. 2) will give the reader a
good idea of this variation. The dark portion, which
looks like a silhouette of a cathedral city, shows the
change of the amount of "spottedness " of the sun for
each solar rotation from the year 1867 to 1879 ; the arrows
indicate the "epochs" or times, as determined from a
curve specially smoothed for this purpose, when there are
fewest (minimum) or most (maximum) spots. It will be
noticed that there is not a gradual mcrease of spotted area,

SCALE OF YEARS
0 I 2 3 4 5 6 7 8 9 10 II IZ 13
■ ' ' ' ' ' I ' ' ' ' ' ' '

18340
1943-5
18560
1867-2
1879- 0
IBa9-6
1901 •;?

1 I I I I I I I t I I t I ■

Fig. 3. — The lengths of the period from minimum to minimum
change alternately.

but that, as the diagram shows, there seem to be intermittent
outbursts. From this figure, which includes a whole
sunspot cycle, it will be seen that the time from one
minimum to the next is about twelve years; this, how-
ever, is not always the case. A glance at the next dia-
gram (fig. 3) shows that since 1834 the lengths of these
periods are alternately longer and shorter than the pre-
ceding one, the mean length being a little more tiian
eleven years. It will thus be seen that the
so-called " eleven year cycle " of sunspots is only
approximately true. A reference again to figure
2 shows further that the epoch of maxinmm
occurs nearer the preceding than the following
minimum ; this is always the case, only from
one period to another this interval from mini-
mum to maximum is not the same. To illustrate
this, these intervals are arranged in figure 4
one below the other, and instead of an alter
nate change in length they recur every third
period. Thus if this apparent law holds good the
approaching maximum will occur about a little
more than three years after the last minimum
(this occurred in about the middle of 1901), that is
about the end of the present year (1904). Another curious
fact relating to the sun-spot cycle is that when the interval
from minimum to maximum is shortest, the total amount
of "spottedness" included in the whole period from
minimum to minimum is greatest. This is graphically
shown in the accompanying diagram [fig. 5). The last

YEARS

1 2 3 4 5 6
1 1 1 i 1 1

1834 0

1843-5
«856 0

1667

I I I I I I I

pi„ 4. -Diagram to show that the interval between a minimum and
the following maximum changes in a cycle of about 35 years.

square represents the relative spotted area that may be
expected for the present cycle if the previous conditions
be repeated. . .

The above brief summary of the sun-spot variations
tells us that not only does the heat of the sun change,
but that these changes occur in cycles of about eleven and
thirty-five years. There is, further, another cycle, not
very well indicated, which has a period of less than eleven
years, probably the same as that which is more clearly
defined by the solar prominence ob;ervations to which
reference will now be made.

The solar activity can also be gauged from "pro-
minence " records. These disturbances are probably of
more consequence than those of spots. The latter are
strictly limited as regards position on the sun's surface

KNOWLEDGE & SCIENTIFIC NEWS.

[Jan., 1905.

to a comparatively narrow zone near each side of the
solar equator, while there seems no such restriction to the
former. Again, if the relation between the areas of spots
and prominences be considered, those of the former are
practically insignificant. A study of prominences is
therefore of the highest importance when tiie activity of
the solar atmosphere is in question, but, unfortunately,
records of these only commence in the year 1870. Unlike
sf)ots, which, as previously pointed out, are the result of
the descent of comparatively cool matter from the upper
regions of the solar atmosphere, prominences consist of
ascending currents of highly-heated matter from the lower

a»40-135 I8«J-S40

Fig. 5. — If the areas of all the sunspots which appear on the Sun's disc
minimum to the next be added together, then the abDvc squares
relative change of spotted area for each of the periods from the year

to the higher layers; indeed, tliey are the precursors of
spots and are thus more direct indications of solar disturb- |
ances. That they are very important factors in solar 1
" weather " can be gathered from their enormous magni-
tudes.someof them being 100,000 miles or more in height
and correspondingly broad.

Prominences, like spots, ha\e periods of maximum
and; minimum frequency. As a rule, when there are
few , spots there are few prominences, and when the
spotted area is large so is tliat of the prominences.
'1 here is thus a very close connection between these two

Ht- <>■- A picture of the Sun taken in light of one colour, showlni:
that there are other areas on the solar disc which are more
eitentlve than those of spots. The former appear bright while
the latter are dark.

phenomena ; but it must be stated that this connection
only holds good when the prominences situated nearest
the equatorial regions of the sun are alone taken into
consideration. It is due, however, to the fact that pro-
minences are at times very numerous near the solar
poles that the curve representing the mean variation of
their frequency from year to year does not rise or fall
gradually throughout a cycle, but is of a wavy nature, as
can be seen by a glance at the curve shown in a subsequent
figure (fig. 7). It IS this peculiarity that makes the promi-
nence curve so important, for these "humps" on the main

curve represent solar changes of activity that are scarcely
traceable on the spot curve. There seems reason to
believe, therefore, that the observations of prominences
are capable of giving us far more information regarding
the circulation and activity of the solar atmosphere than
those of spots.

We thus see then that the study of spots and promi-
nences has made us acquainted with three different
periods of solar changes. Thus we have a short period
of a litlle less than four years, another cycle covering in
the mean a little more than eleven years, while a third
variation occupies about thirty-five years.

Having thus briefly summarised the chief
facts concerning the various changes of solar
activity, attention will now be paid to the
records of meteorological phenomena to see if
any trace can be found corresponding to these
solar variations. The question now arises as
'~ "" ■ to which meteorological element should be

chosen to commence operations with. For
show the several reasons, which need not be mentioned
'834. here,barometricobser\ationshavebeen selected,

for they supply us with an excellent means
of detecting variations of pressure which are direct indica-
tors of air movements towards or away from the earth's
surface. Greater solar radiation means greater heating
power, and therefore stronger ascending currents away
from the earth in some parts of the world, and conse-
quently greater descending currents in other parts ; thus
we should expect to find lower and higher pressures
simultaneously in different regions of the earth's surface.
A decided great advantage in employing barometric
records is that the variations of this element from year to
year are very similar over large areas, and do not change
according to local conditions as is the case with rainfall.
Thus, to take the case of the British Isles, for example,
the pressure variation of, say, Oxford is quite sufficitnt
to illustrate the variation o\er the whole of the British
Isles, as if we employed the records of N'alencia, .Aber-
deen, Greenwich, or Edinburgh, which are all quite
similar. Rainfall is the effect and not the cause of baro-
metric pressure variations, and we in these islands are
quite familiar with this fact. A fall in the barometer
with us generally means rain, and a rise probably dry
weather. Rainfall then being an after-effect of pressure,
any variation of the latter should have a very close
connection with the former.

{lo be continued.)

Messrs- Adolph's Selenivim Cells.

Wc have received from Messrs. Adolph, of Farringdon
Koad, a catalogue of their selenium ceils; and selenium
cell apparatus. The great interest of selenium to the cleclri-
cian lies, as everybody knows, in the alteration which becomes
apparent in the electro-conductivity of this element as the
light thrown on it varies. The relation between the change of
electric resistance and the amount of illumination has been
expressed mathematically ; and if selenium could always be
depended on to behave with perfect regularity, some of the
practical uses to which it could be put might effect astound-
ing revolutions in light telephony. Hcrr Kuhmer, in Herlin,
has endeavoured to transmit sounds along beams of light by
the employment of selenium cells, and within ccrf.iin limits
the experiments have been successful. What is wanted most,
however, with regard to selenium, isncw and continued experi-
ment ; and the opportunity which Messrs. Adolph aflord of
bringing within the reach of laboratory students selenium
cells of all kinds, as well as apparatus for testing its properties
in light telephony, and its applications to other branches of
research, is one that wc warmly welcome.

Jan., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

Electrotyping.

Bv Dr. F. Molluo Perkin.

.\'o one has been long in a chemical laboratory without
having learnt that one of the simplest tests to ascertain
whether a solution contains copper is to place the
blade of a pen-knife into it. If copper is present the
blade of the knife becomes covered with a thin coating
of copper. Other metals besides copper can be plated
out upon another metal by simply immersing it in their
solutions. For example, if a silver article is dipped
into a solution containing a gold salt, it will become
covered with a thin coating of gold. This process of
dipping is to a certain extent actually performed in
practice, hence one is accustomed to talk of giving an
article a gold wash. For example, at one time the
method employed for gilding the inside of silver boxes,
the bowls of spoons, &c., was to wash them over with
a piece of rag w hich had been dipped in the gold solu-
tion. When a metal is plated by simply immersing it
in the solution of the other metal, then an equivalent
of the metal w^hich is being plated upon it goes into
solution. Thus, when the blade of a knife is placed
into a solution of a copper salt and becomes superfici-
ally coated with copper, it is only done at the expense
of a portion of the blade which goes into solution.
Supposing the solution to consist of copper sulphate,
then as copper is deposited out, sulphate of iron takes
its place. Thus we can write it in the form of an
equation :

Copper sulphate -j- iron = iron sulphate + copper
or by using symbols

CuSCj 4- Fe r= FeSC, -|- Ca.

The metal which gees into solution and upon which
the other metal becomes plated out is said to be electro-
positive to the metal in solution. Zinc is the most
electropositive of all metals, and under appropriate con-
ditions is able to replace all other metals from the
solutions of their salts.

Now this method of plating or depositing out a metal
has only a very limited application. It is used to a
certain extent in gold plating, but not for depositing
such a metal as copper. The methods employed are
electrolytic. It is found if an electric current is
passed through a solution of a metallic salt, e.g., copper
sulphate, that the ccpper is deposited out upon the one
electrode,* and at the other electrode if it is of an in-
soluble material, such as platinum or graphite, oxygen
gas is evolved. The pole at which the metal is de-
posited is called the negative pole or cathode, the one
at which oxygen gas is evolved, the positive pole or
anode. Fig. i shows such a cell diagramatically. A
is the negative electrode or cathode ( — ) and B is the
positive electrode or anode (+)■

If instead of being made of an insoluble material the
anode B consists of a sheet of copper, then as the
electric current passes the copper will go into solution.
Furthermore, the copper will pass into solution at the
same rate as the metal is plated out upon the
cathode A; theoretically, therefore, the strength of the
solution will remain constant. As a matter of fact,
owing to secondary changes, after a time it becomes
too concentrated.

* When two pieces of metal connected with the opposite poles of
an electric battery are immersed in a solution, as ^hown in the
figure, these pieces of metal are called electrodes.

Electroplating was first suggested by Elkington in
1836, but he did not apparently employ it on an indus-
trial scale. It is very interesting to note that some of
the articles obtained from the coffins of the Egyptian
mummies have been found to be coated with copper;
probably, however, the coatings of copper in these
cases were produced by simple immersion. On an in-
dustrial scale electroplating w-as first introduced by
M. H. Jacobi, of St. Petersburg, in 1838. Since then,
especially of late years, an enormous industry has been
developed. By simple immersion heavy deposits of
metal cannot be obtained, but coats of any thickness
can be produced by electro-galvanising. In this article
it is intended to deal not with plating in general, but
with the application of the electric current for producing
electrotypes or reproductions; this form of electro-
deposition is sometimes called galvanoplastic.

In all cases of reproduction the article to be repro-
duced is made the cathode in a bath of copper sulphate,
and a strip of copper the anode. Xow, supposing it is
desired to reproduce a medallion, if this be of metal
and is made the cathode, copper will be deposited upon
it, but the copper will adhere so firmly that it will be
i-npcssible to remove it. It is, therefore, necessary to

coat the medallion with an extremely thin film of son-.e
material which will prevent the deposited metal from
adhering to the metallic surface. This coating must
not be sufficiently thick to obliterate or blur the details
of the figures, &-c., upon the article which it is desired
to reprcduce. There are several methods which may be
employed. If the medallion is of silver cr copper, its siir-
face after being carefully cleaned so as to remove dirt
or grease, is washed with a solution of sodium sulphide,
by which means the surface of the metal is coated
w'ith an extremely thin film of sulphide of the metal.
This surface is co'nducting, but preventr^ the deposited
metal from adhering to the article. Another method is
to cover it with a thin coating of black lead (plumbago).
The coating must be very thin and should be polished
in much the same way as the iron-work of a fire-place
is polished. In practice, machines are generally used
for polishing and plumbagoing surfaces, as it is not
an easy matter to get a perfectly smooth and even
surface by hand.

Having satisfactorily prepared the surface of the
article, it is hung by means of a copper wire in the
depositing bath and connected with the negative pole
of the source of current. The conducting wire where
it dips below the surface of the copper solution should
be covered with an insulating material, such, e.g., as
a piece of rubber tubing. As soon as the circuit is
closed and the current passes, the surface of the article
becomes coated with a thin film of copper, xN-hich gradu-
ally increases in thickness, until a coating of about
1 to ^ a millimetre in thickness has been obtained. It

KNOWLEDGE & SCIENTIFIC NEWS.

[Jan., 1905.

should be mentioned that the back of the article is
coated with some non-conducting material, such as solid
paraffin wax, otherwise the whole article would be-
come covered with copper, and it would then be im-
possible to remove the deposited metal. In depositing
the metal certain precautions have to be taken. Thus,
for example, the regulation of the current strength
(current density) is a matter of great importance. If
a heavy current is employed, the copper is very apt to

be deposited in a rough and irregular form, and may be
so powdery as to actually rub off. The colour of the
copper is bright, and the appearance smor)th and regu-
lar when low currents are employed, but it is rough
and brown (burnt) with currents of too great intensity.
When a sufficiently thick deposit has been obtained
the article is removed frf)m the bath, well washed with
water, and dried. The point of a pen-knife or other
sharp instrument is then inserted under the edge of the
deposited metal and the metallic coating carefully

stripped from the article upon which it has been de-
posited. Sometimes it is rather difficult to strip it with-
out bending and injuring the thin metallic shell, and
when this takes place it is not by any means an easy
matter to properly smooth it out again. The thin shell
thus obtained is backed up with lead or with an allov
of lead, which melts at a lower temperature than the
lead itself. In order that the backing metal may adhere
satisfactorily, the back of the shell must first be tinned;
a satisfactory tinning mixture consists of an alloy of
50 parts lead and 50 parts tin. The hacking metal is
then run in; a useful allov for this purpose consists of
90 parts lead, 6 parts antimony, and 4 parts of tin.
Wood's alloy is sometimes used, but is too expensive
for ordinary practice. It consists of an alloy of lead,
tin, cadmium, and bismuth, and melts below the tem-
perature of boiling water.

A complete copy of a modal can be obtained by de-
positing the metal first on one side and then on the
other. The two shells thus obtained are, after tinning.

placed back to back and the fusible alloy run in between
them. After filing and polishing the edges, copper can
be deposited on the rim when the whole — reproduced —
medal appears to be composed of copper. Fig. 2, A
and B, shows a photograph of two sides of a medal
commemorating the French revolution, and reproduced
in the above manner. The original medal was in this
case coated with sulphide. It is seen that by the
above method even the faintest lines are reproduced, and
we are thus able to obtain an absolutely exact replica
of medallions or engravings.

Another and more commonly employed method is to
make a cast or matrix of the object which it is desired
to reproduce. This may be done in a variety of ways.
Sometimes a metallic cast is made directly from the die,
and upon this cast a thin film of copper is deposited.
Fig. 3 shows such a repioduction which was cast in
soft metal, then thinly coated with copper and treated
so as to give it the appearance of bronze. The medal
appears, in fact, exactly as if it was made of bronze.

Jan., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

Another method, and the most usual, is to prepare a
plaster cast and render this impervious to water by
impregnating it with melted paraffin, a£ter which the
surface is coated with graphite to make it able to con-
duct the electric current. Sometimes instead of

graphitising, it is coated with a thin film of silver by
chemical means. After having been rendered conduct-
ing, the cast is made the cathode in a plating bath and
metal deposited as already described. When a suffi-

ciently thick deposit has been produced the cast is taken
out of the bath, the deposited metal removed and
backed up as already described. The deposited metal
gives a faithful reproduction of the original medal.
Fig. 4 was reproduced from a plaster cast.

Instead of using plaster to make the cast, guii.i-
percha or mixtures of gutta-percha and other substances
are often employed. Fig. 5 is rather interesting. It was
made from a gutta impression. Happening to be
short of gutta, my assistant, Mr. \V. C. Prebble, to
whom my thanks are due for preparing the medallions
illustrated in this article, produced two golf balls, and
the gutta from the interior of these was employed for
making the matrix. The gutta was first kneaded in
hot water to render it plastic, and then carefully worked
on to the medal, after which it was pressed in a letter-
press; hydraulic presses are often used on a commercial
scale. The matrix so obtained was made con-
ducting with finely-powdered graphite and was then
placed in the depositing bath. This medal contained a
great amount of detail, and I think it shows how ex-
tremely useful a golf ball may be on occasion. On a
future occasion further illustrations of the uses and
applications of the electric current in reproduction
work mav be tji^'cn.

-^^.^^^^

PhotogrsLphy.

Pure and Applied.

By Ch.ap.max Jones, F.I.C, F.CS., &c.

Dr. RusseWs Experimenls. — The production of the
developable condition in silver bromide, when it is ex-
posed to the action of certain clean metals, notably
zinc, and other substances such as turpentine, boiled
oil, printers' ink, and sections of wood, is still obscure.
Dr. Russell has found that a very minute porportion
of the vapour of hydrogen peroxide is able to produce
a similar effect, and that hydrogen peroxide is produced
when many, if not all, of the substances found to be
active are exposed to the air, as they are in the experi-
ments. Again, Dr. Russell has shown that whatever
it is that affects the plate, it behaves in some ways like a
vapour or gas. It appears to be carried along a tube by a
current of gas, it creeps over the edges of plates when
they are placed with their glass sides towards the active
substance, and so on. If this was all that there is to
be said, we should probably rest satisfied with the idea
that hydrogen peroxide itself is the active agent. But
some of the experiments render it difficult to believe
that it is only the production of a vapour at the sur-
face of the active substances, which diffuses, as a
vapour would diffuse, towards the photographic plate.
Dr. Russell himself has several times drawn attention
to this difficulty, though latterly he has apparently
passed it over, considering that his experiments prove
that hydrogen peroxide is the active agent in spite of it.

Dr. Russell has shown that gelatine is not porous;
tlierefore it may be assumed that if a vapour passes
through it, it must be absorbed on one side of the gela-
tine sheet, work through it, and be given off at the
other side. He has shown that it does take time to
pass through, but the difficulty is that a practically
sharp reproduction of the active surface is obtained
instead of a considerably blurred image, such as one
would expect from an active vapour passing through
such an obstruction. Dr. Russell has said "a good

KNOWLEDGE & SCIENTIFIC NEWS.

[Jan., 1905.

clear picture " is obtained " even witii two sheets of
gelatine. " When there are interposed " even as many
as six or more sheets, still the picture of the scratches
is distinct." " It is remarkable that such a vapour
should readily pass through media such as g-elatine,
celluloid, etc., and not by mere absorption, but in such
a way as to produce a picture of the surface from which
it emanated." " The remarkably clear pictures .
which can be produced through a sheet, or even several
sheets, of the thin gelatine, proves that the action is
not one of mere absorption." In his third paper on
the subject, read before the Royal Society, Dr. Russell
says, •• How then does the peroxide permeate the gela-
tine? Not by the ordinary process of diffusion, for
hydrc^en cannot diffuse through it, so that it must be
bv a process of dissolving, or very feebly combining
with the medium, or with a constituent of it, and, thus
travelling through, escape on the other side. That the
action is of this nature seems rendered probable by the
following experiments." These experiments consist in
placing a succession of plates, each for twenty min-
utes, over a solution of hydrogen peroxide covered with
a thin sheet of gelatine, and show that the active agent
apparently takes time to penetrate the gelatine. Tlie
first plate showed no result, the second a slight action,
the third still more, and so on. The same kind of
action takes place if zinc is used instead of hydrogen
peroxide, or celluloid instead of gelatine.

Thus the production of a detailed image, although
several sheets of gelatine were interposed between the
active substance and the plate, was acknowledged by
Dr. Russell as ditlicuit to understand, and he says in
another place that it " seemed to prove that the action
was not a mere absorption on the one side and a giving
out on the other." The effect points to the obvious sug-
gestion that the effective agent is some form of radiant
energy. In 1898 I suggested that as all the active
substances experimented with in this connection were
susceptible of oxidation by mere exposure to air, and
as during their vigorous oxidation (combustion) a form
of radiant energy which will affect a photographic
plate was certainly produced, it might be that the slow
oxidation produced a similar form of radiant energy,
just as the total heat effect is supposed to be the same
whether the oxidation is slow or rapid. I pointed out the
relatively enormous exposures given in Dr. Russell's ex-
periments. One ten-thousandth of a second is cer-
tainly ample time to produce the developable condition
in the silver salt of a gelatine plate when it is exposed
to burning zinc, and it seems not unlikely that an
exposure of, say, six hours to the slowly oxidising
metal should produce a similar effect, for this increase
in the time of exposure is equal to the increase of from
one second to more than six-and-a-half years.

There have been other opinions expressed, and
suggestions offered, with regard to the character of
the cause of these effects, and these I propose to refer
to next month.

Zambcx cameras — flat film changing. — These cameras
now being introduced by Messrs. R. and J. Beck, are
distinguished by the novel and ingenious method of
changing the filmN. This operation is accomplished by
opening wide the solid hinged lid at the back of the
camera, so that the zambex envelope, which is rather
more than twice the length of the film, is opened out
flat and to its full length. A numbered tab, corre-
sponding to the exposed film, is then firmly drawn along
away from its position in front of the bundle until it
is in that part of the envelope that is attached to the

lid. This leaves the next film ready for exposure, the
lid, of course, being first closed. The film carriers
are pieces of moderately- stiff black paper with pro-
jecting tabs to pull them by, and they arc attached to
one another by thinner paper that rolls over as each
is drawn along, and so prevents any friction against
the surface of the next film. If it is desired to focus,
the exposed films may be pushed back into their
original position, and the envelope with it-s whole
charge removed to make room for the screen.
On replacing the arrangement for the next ex-
posure the exposed films are drawn up again. When
ihe last is exposed, the film carriers are all pushed back,
and the envelope, with its contents in the same relative
positions as before use, is removed to make room for
a new one. The zambcx skeleton, or series of carriers,
in its envelope, may be obtained loaded with films, and
then all the changing operations are done in daylight;
they are also supplied empty, that the user may charge
them with any films preferred. The skeletons may be
used five times if desired, being provided w-ith five holes
to take a staple that retains all except the one that is
being removed from the front. Zambex skeletons are
also made to carry three plates instead of twelve films.
The advantages of this new device are obvious. Each
envelope with its full charge is less than half an inch
thick, so that the packages are compact as well as
light.

The Piesmic Barometer.

A new mercurial barometer, wliich lias been designed by
Mr. A. S. Davis, M.A., and has been called by him Ihe Piesmic
barometer, is an ingenious adaptation of an easily understood
principle in the relation between pressure and volume in gases ;
and presents as practical advantages several new features of
convenience, lightness, and trustworthiness. The action of
the instrument depends on the fact that any volume of air
taken at a low pressure, is more compressed than an equal
volume of air taken at a higher pressure, when the pressure
on each volume is increased by the same amount. The follow-
ing is a description of the method of the instrument, which is
of so convenient a size that it could, without very much in-
convenience, be carried in the inner pocket of an overcoat.

ADC is a glass tube, the part AI> being made of strong
capillary tubing of one-tenth inch bore and liC being made of
thin rjuill tubing. A U is seven inches long, and the capacity
of the whole tube is 35 times the capacity
of a single inch of the capillary tubing. The
end /) , opens into a small cast-iron cistern
E containing mercury. The air in this
cistern, though not in actu.il conmiunication
with the external air, is kept at atmospheric
pressure by communication with a small
auxiliary chanibtT, the sides of which are of
thin paraffnied paper. When the tube is
horizontal the mercury lies on one side of
the cistern, leaving the open end A of the
tube exposed to the air. When the tube is
brought into a verticil position the mercury
flows over and closes the mouth of the tube,
then flows down the tube to .1 greater or less
depth, the depth being dependent upon
the atmospheric pressure at the time. If
the barometer is standing at 30 inches the
mercury will descend five inches; if at 29
inches it will descend six inches : if at 2H
inches, seven inches, and so on. A scale of
inches being placed behind the tube, the reading of the end of
the mercury column against this scale shows the height of the
barometer at the time.

Jan., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

ASTRONOMICAL.

Professor Sha-ler's CompaLrison of the
Fea.tures of the Earth and the Moon.

In \'olume XXXIV. of the " Smithsonian Contributions to
Knowledge," Professor Shaler, of Harvard University,
treats of the lunar features from the point of view of a
geologist. He divides them into the broad classes of Maria,
vulcanoids (in which apt term he includes all cup-lil;e forma-
tions from the greatest ring plains to the smallest crater bed),
reliefs (mountains or ridges), v.alleys and rills, and rays. He
discusses and rejects the hypothesis that all or an}' of the vul-
canoids were originated by meteor falls. Were such the cause
the bolide would not only have been itself vaporised by the
heat of collision, but the surface round, for many times its
diameter, would have been melted, and the lava so formed
would have been extremely fluid and more than sufficient to
fill up the pit caused by the entrance of the bolide. Neither
have we evidence on the earth of such numerous and great
meteor falls as would be necessary to account for the great
number of lunar craters. Though the lunar vents indicate
some process of eruption it is evident that this cannot be iden-
tical with that on the earth. Terrestrial volcanoes are due —
at least mainly — to water buried by aqueous sedimentation,
and such occluded water, or its dissociated gases, we cannot
admit upon the moon. Professor Shaler suggests some kind
of boihng, such as will take place in any fluid mass which is
heated below and cooled on the surface (as in molten iron),
where substances in the vaporous state, though they exist, are
not present in sufficient quantities greatly to affect the move-
ment, or there is a, circulation mainly impelled by the escape
of imprisoned vapours.

* * *

But the Maria are attributed by Professor Shaler to the fall
of great bolides, though many of the arguments, which caused
him to reject this as the origin of the vulcanoids, hold good.
Besides the Maria are arranged in such symmetrical fashion,
almost exclusively in the moon's northern hemisphere, that it
seems impossible to consider them as owing their origin to such
haphazard casualties as a meteor fall. Professor Shaler con-
siders that the low ridges which extend for many miles across
the Maria are more nearly analogous to terrestrial mountain
chains than the rugged reliefs which are usually called moun-
tains on the moon. The light rays, he considers, owe their
hue and brightness under a high sun to a crystalline deposit
which reflects sunlight chiefly when vertical. This is almost
proved by their shining also under earthshine, and the bright
patches are probably of the same nature.

The problems raised are numerous, and Professor Shaler
states several in a manner that may help to their solution. As
regards the vexed question of change on the moon, he strongly
decides against the possibility of present volcanic action. If
Linne has changed he attributes it to the creeping action
caused by the great changes of temperature, assisted perhaps
by a blow from a chance meteor. As to the presence of
organic life, he points out that there is none at all on terres-
trial mountain peaks above 30,000 feet, where the earth's
atmosphere is but one-third its density at the surface.
Organic life has failed to adapt itself here to the conditions,
much less could it originate. How then can we conceive of
it on the moon ?

♦ • *

For one problem he can suggest no solution. If meteoric
dust falls on the moon in the same proportion as on the earth

— and we have no reason to suppose otherwise— and during
past time in as groat quantities as now — and we have no reason
to suppose that it was less — how is it that the moon, unpro-
tected by any atmosphere, has preserved its clean reliefs and
its varied hues, and has not had all masked under a uniform
veil ? Especially how i? it that the bright rays — differing
widely in the date of their origins — which seem but stains on
the surface, are still bright, and the older rays no less bright
than the later?

Return of Tempel's Second Periodica.1
Comet.

Three short-period comets belonging to the Jupiter family
were discovered by Herr Tempel. Of these the one discovered
in 1 87 J has the shortest period, and was due to return to
perihelion this year. It was re-detected by M. Javelle with the
30-inch refractor of the Nice Observatory on November 30,
though it was of the most extreme faintness, and set within
three hours after the Sun. It appears to have been seen only
on two nights, but the observations show a most gratifying
precision in M. Coniel's ephemeris; the error being only four
seconds of time in R.A, and four seconds of arc in declination.
But for M. Javelle's two observations the comet would prol)al)ly
not have been seen at this return at all. Its previous appear-
ances were in the years 1S73, 1878, 1894 and 1899 ; the returns
of 1883 and 1889 having been unobserved.

Discovery of a Ne'w Comet.

A new comet, aliout the nth magnitude in brightness, was
discovered on December 17 by M. Giacobini, of the Nice
Observatory, just on the borders of the two constellations of
Hercules and Corona Borealis. It was a morning object,
moving in a north-easterly direction. It will not become at
all a conspicuous object, as the following elements show : —

T = i905 Jan. 3d., 2814, Berlin M.T.

«= 75° 9'-S]

il= 225 1-2 J- 1904-0

1 = 103 273 J

log q= 0-27173
The inclination being very great and the motion retrograde,
it is exceedingly unlikely that the comet is a periodic one.
Its perihelion distance is large, lying much outside the orbit
of Mars.

* * *

The Grea-t R-ed Spot of Jupiter.

In Astronomischc Nachrichtcn, No. 3983, there are two in-
teresting notes on Jupiter's great red spot, by the e.xperienced
observers, Mr. A. Stanley Williams and Mr. W. F. Denning.
The two notes are all the more interestinginthatthey seem to
indicate very different results. Mr. Stanley Williams gives the
value for the relative period of the spot as gh. 55m. 41-523. in
1903 from 4S5 observations, as compared with gh. 55m. 3g-6bs.
in 1902, and writes : " This is a remarkable increase from the
value obtained in the preceding year. The changes during
the past five vears have, in fact, been very considerable. . .
Such large and comparatively sudden changes are particularly
interesting in the case of an object like the red spot, since in
conjunction with its unchanged aspect they appear to indi-
cate, firstly, the relatively great rigidity or solidity (using this
word in a comparative sense) of the spot itself, and secondly
the mobility of the material surrounding it, and in which it
appears to float. There was no noticeable change either in
shape or appearance last year, though, owing to the higher
altitude of the planet the spot was a comparatively easy
object, and its outline could be distinguished without difliculty.
There may, however, have been a slight real increase of
plainness." • • j

Mr. Denning, on the other hand, finds for the rotation period
during the last seven months, gh. 55m. 38-6S., which, he writes,
" is shorter than any period it has exhibited since 1883. In
1883 it was gh. 55m. 38-2s., and in 1884 gh. 55m. 3g-os. The
spot is now very faint. Its variable motion in recent years has
been very curious, and it will be highly interesting to watch
this object during ensuing months, and trace out any further
changes in velocity."

KNOWLEDGE & SCIENTIFIC NEWS.

[Jan., 1905.

R^efraction in Planetary Occultations.

A lunar occultation is usually an instantaneous phenomenon,
the moon possessing no atmosphere sufficient to cause a sensi-
ble refraction of the light of the star occulted. But several
of the planets evidently possess considerable atmospheres,
and it might at first sight be expected that an occultation of
a star by one of them should show a noticeable effect ; a re-
tardation of the disappearance and an acceleration of the
reappearance. Dr. T. J. J. See in No. 39S4 of the .Istroiw-
michc- Kachriihtctt shows that in general there is a zone of
irradiation round the disc of a planet many times the greatest
admissible depth of the atmosphere. A daylight occultation
would be free from this irradiation effect, but the observation
of such an event under good conditions must be most r.ire ;
whilst in an occultation at the dark limb in the case of Mars
or \'enus the limb of the planet would be unseen, and " it is
difficult to see how any result of value could be obtained."

The Greenwich-Paris Longitude.

M. Loewy, in a communication to the Paris .\cademie des
Sciences gives the final result of the determination of the
difference of longitude between the two Observatories which
was carried out by MM. Bigourdan and Lancelin in 1902.
Some small differences were noted between the values obtained
in September, 1902, and those in .April and May, which are
ascribed to slight changes in personal equation. The mean
result gives the difference of longitude as 9m. 20-974S., the
value found independently by the two English observers,
Messrs. r>yson and Mollis, being 9m. 20-g4S. ; a difference of
only the thirtieth of a second of time. The difference of
longitude between the two meridians may therefore be
considered as now known with most gratifying precision.

Sunspot Spectra.

The Rev. A. L. Cortie, S.J., gives in the Astrophysical
Journal for November an interesting summary of his obser-
vations of sunspot spectra during the years 1883- 1901. His
spectroscope was an automatic twelve-prism instrument by
Browning, each prism being of 60 refracting angle. The
region examined was the red and yellow ; from B to D ; and
349 lines are contained in the catalogue of widened lines — the
individual observations being 54S6 in number.

The summary of results shows the important part played by
the faint lines of vanadium and titanium in the spectra
of sunspots. Lines which in the earlier observations were
classed as of unknown origin have since been found to
be due to vanadium or titanium. These faint lines are
always at all times of the sunspot period among the most
widened lines ; X 6243"o6 of vanadium being particularly
noticeable. Father Cortie finds no evidence of the " cross-
ing points " when these vanadium and titanium lines give
way to lines of iron, such as Sir Norman Lockyer has in-
sisted upon so strongly; nor is he inclined to admit that there
is warrant for concluding that there is an essential difference
of character or temperature between maximum and minimum
spots. He regards the widening of some of the oxygen lines,
especially in the a Vjand, as a real phenomenon, but considers
that the apparent evidence for the widening of lines accredited
to water vapour requires support from further research before
it can be definitely received.

♦ ♦ »

The Astronomical and Scientific Bequests
of Mr. Frank McClean.

Mr. Frank McClean, F.K.S., has made the following be-
quests: 1^5000 to the University of Cambridge, to be expended
in improving the instrumental equipment of the Newall Ob-
servatory; ;{'5ooo to the University of^Birmingbam for physical
science ; £2000 to the Koyal Society ; ;f 2000 to the Koyal
Astronomical Observatory; /'2000 to the Koyal Institution;
and to the University of Cambridge, for presentation to the
Fitzwilliam Museum, all the testator's illuminated or other
manuscripts and early printed books, and all objects of
media:val or early art which the Director of the Museum may
select as being of permanent interest to the Museum.

The Medals A^varded by the Royal

Society.

The Copley Medal has been awarded to Sir William Crookes
for his experimental researches in chemistry; the Rumford
Medal to Professor Ernest Rutherford for his researches on
the properties of radio-active matter ; one Royal Medal to
Professor W. Burnside, on the ground of the number, originality,
and importance of his contributions to mathematical science ;
the other Koyal Medal to Colonel David Bruce for his success-
ful researches into the causation of a number of important
diseases affecting man and animals ; the Davy Medal to Pro-
fessor W. H. Perkin, jun., for his researches in the domain of
synthetic organic chemistry ; the Darwin Medal to Mr. William
Bateson for his researches on heredity and variation ; the
Sylvester Medal to Professor Georg Cantor for his researches
in pure mathematics; and the Hughes Medal to Sir Joseph
Swan for his invention of the incandescent electric lamp and
his other inventions and improvements in the practical
applications of electricity.

BOTANICAL.

S. A. Skan.

It is announced in the December number of the Botanical
Magaziiu- that Sir J. D. Hooker, who has been the editor of
this famous periodical for the long term of forty years, retires
from that position with the completion of the volume for 1904,
on account of his great age, Sir Joseph now being in his eighty-
eighth year. It is further stated that a new series begins in
January, 1905, with Sir William Thiselton-Dyer, K.C.M.G.,
Director of the Koyal Botanic Gardens, Kew, as editor. For
some time past Mr. W. Botting Hemsley, F.R.S., has given
Sir J. D. Hooker a great deal of assistance in carrying on the
work, most of the text in the last volume having been contri-
buted by him. The Botanical Maf;aziitc has now appeared
uninterruptedly for n 8 years. Mr. Hemsley. in his interest-
ing history of the work, which was published in the Gaydeiurs'
Chronicle in 1887, refers to it as " having long outlived the
numerous rivals and imitators which its successful career gave
rise to from time to time. Indeed, it is doubtful if it is not
the only illustrated serial ever published that has enjoyed a
century of unbroken vitality."

In the Comptcs Rcndus, Vol. CXXXVIII., p. 293, Messrs.
Bouilhac and Giustiniani have an interesting article on the
important question of the utilisation of free nitrogen by
various higher plants through the medium of certain fresh-
water alg<E (A'os^if />H»f/ i/oj-Hif and Auahana) associated with
bacteria. Nitrogen, one of the essential constituents of plant
food — the development of proteid substances depending on
its presence — though so abundant in the atmosphere, is shown
by experimenters, amongst whom may be mentioned De
Saussure, Boussingault, Lawes and Gilbert, to be inaccessible
to plants in its uncombined state, and that the majority of
them are dependent for their supply of the gas to nitrogenous
manures incorporated with the soil in reach of their roots.
Leguminosa; are remarkable in being able to make use of the
atmospheric nitrogen, which is fixed and rendered diffusible
for them by the agency of bacteria infesting the nodules often
found in abundance on their roots. The writers referred to at
the beginning of this note show that other plants besides
Leguminosa;, such as buckwheat, mustard, cress and maize.will
thrive when the source of nitrogenous food is restricted to the
nitrogen of the air, so long as certain algie and bacteria are
present in the soil. These appear to be able to convert the
gas into a form accessible to the plant in the same way as do
the bacteria in the root-nodules of the Leguminosa;. Messrs.
Deherain and Demoussy had previously ascertained that even
a IcKimiinous plant (t.iipiniis) would flourish in soil deprived
of nitrogenous ingredients, and without developing nodules on
its roots, if alga; were present.

Jan., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

ORNITHOLOGICAL.

By W. P. Pycraft.

Breeding Habits of Pterocles Ex\ist\is.

Mk.W. H. St. Quintin, in the December number of the Avi-
cultural Ma^a,-:i>u; gives an exceedingly interesting account
of the habits of the greater Pintailed Sandgrouse (Pterocles
cxnstus), which he has succeeded in breeding in his aviary this
year — the first record of the kind in this country.

In the course of his essay he descril>os the curious method
which the birds have of watering their young. As this is
probably new to most of our readers we venture to reproduce
it here. " The young," he says, " no doubt are somehow able
to make it clear to their male parent that they wish to drink,
and he starts off to the pan, and, after sipping a little on his
own account, steps in and stands motionless for a minute or
two watching. Then he sits down in the water, and goes
through a shuffling movement very like a bird that is dusting-
After remaining in the water several minutes he gets out and
hurries off loudly calling to the young, who, if old enough, run
to meet him. Then follows what reminds me more than any-
thing of a mammal suckling her young; the chicks push their
heads amongst the breast-plumage and under tail-coverts,
evidently taking the water off the feathers by passing them
through their bills, moving to fresh places as the supply becomes
exhausted."

Pterocles alchatus has the same custom ; a fact first noticed
by Mr. Meade-Waldo. As in the species just described, only
the male undertakes this work.

The habits of these birds in confinement thus throws unex-
pected light on certain peculiar habits seen in wild birds of these
species and the allied Pterocles ((rt';!(iriH,s, which were observed by
Mr. Meade-Waldo soaking their breasts in puddles about the
village wells in Morocco and then flying off.

Breeding Colonies of the Flamingo.

In a charming and beautifully illustrated article in the
Century for December, Mr. Frank Chapman describes the
breeding habits of the Rosy Flamingo [Plia-nicoplerus ruber).
His observations were made in the Bahamas ; and since but
little is known of the breeding habits of Flamingos, his account
will be eagerly read by ornithologists.

If any doubt still lingers in the mind of any of our readers
as to the truth of the old story of the method of incubation
which these birds, on account of the great length of their legs,
were obliged to adopt — brooding the eggs by sitting astride
the nest ! — they should be dispelled by Mr. Chapman's photo-
graphs.

In view of the opinions which have been expressed as to the
systematic position of the Flamingo, it is interesting to notice
that the young are goose-like rather than stork-like, inasmuch
as they are precocious. Nevertheless, unless suddenly
alarmed, they remain in the nest for a few days after hatch-
ing, and are fed by the parents on what is described by the
author as " regurgitated clam broth," which is taken, drip by
drip, from the parent's bill. It would seem, however, from the
author's description that only their first meal is of this
character, and that henceforth the birds feed themselves
under the parents' guidance. Thus, in this matter, they
further resemble the Anseres.

Unfortunately, owing to the unavoidable publicity which
Mr. Chapman's search for these birds occasioned, this huge
colony is doomed to extinction. Hitherto undiscovered, its
whereabouts has now become known to the negroes of the
island. And as fresh meat is " rarer then pink pearls " in the
outer Bahamas, and young Flamingos are regarded as excellent
eating, a relentless war on the colony has begun.
* * *

Sabine's Snipe in Cambridgeshire.

A remarkably fine specimen of the so-called Sabine's snipe
was killed in November at Fulborn, Cambridge, on the estate
of Captain Tryon.

Now known to be only a melanistic variety of the common

snipe, this bird yet presents some striking points of difference
from the normal type. Though I have recently examined
several specimens, in none have I remarked the characteristic
longitudinal striping on the upper parts, or the bars on the
axillaries.

The present bird, a female, may be described as velvety
black above, relieved by brown markings, forming horse-shoe
shaped bars at the tips of the feathers of the scapulars and
mantle. The dark colour around the face was so intense as
to form a sort of mask, comparable in area to that of the
black-headed gull in summer dress. The beak and feet were
of the normal colour.

Only in a few rare instances has the sex of these varieties
been recorded, though between fifty and sixty examples are
known. Of these, thirty-one have been obtained in Ireland,
twenty-two in England — the present specimen makes the
twenty-third — one in Scotland, and one in France.

This appears to be the first record for Cambridgeshire.

* * *

The Thrush-Nightingale in England.

The first authentic British-killed example of the thrush-
nightingale (Daulias philomela) was obtained at Smeeth, Kent,
on October 22, and was exhibited at the British Ornithologists'
Club on November 16. It proved to be a male.

Known in Germany as the " Sprosser " nightingale, this
species differs from the common nightingale in its somewhat
larger size and the presence of faint spots on the throat ; but
it is inferior as a songster, as compared with its smaller
relative.

* * *

Water Pipits at Rye Harbour.

An immature male water-pipit (Anthus spipoletta) was shot
at Rye Harbour, Sussex, on October 26, 1904. It was pro-
cured out of a flock of rock-pipits. On November ig, a
female, also an immature specimen, was killed at Pevensey
Sluice, Sussex.

Mr. M. J. Nicoll, who exhibited these birds at the Novem-
ber meeting of the Ornithologists' Club, remarked that he had
but little doubt that the water-pipit was a regular visitor
to England during the autumn migration, but escaped notice
owing to its resemblance to the rock-pipit.

They seem to prefer salt and brackish pools as a feeding
ground.

» » »

Spotted Crake in Co. Antrim.

A young female Spotted Crake (Porsana inaruetta) was killed
on October 8 at Templepatrick, Co. Antrim. This makes the
sixth occurrence of this species in Co, Antrim.

* * »

In\migraLtion of La.pland Buntings.

A small flock, at least, of Lapland Buntings (Plectrophanes
lapponica) would seem to have reached our shores this autumn,
inasmuch as a bird of this species was taken in a trap at
Acock Green, near Birmingham, on November 21 ; and two
on the denes at Great Yarmouth, a female on the iSth and a
young male on the 24th of November.

* » #

Hoopoe in Cheshire.

An immature Hoopoe was, records the Zoohv^ht, shot in
a potato field at Sale, Cheshire, on September 21. This bird
had been seen in the neighbourhood since the 17th, and was
verv tame — a trait which unfortunately cost the wretched bird
its life ! These birds would undoubtedly breed in this
country if left alone when they arrive in the spring, as
many do.

* * *

Black-necked Grebe breeding in Grea-t
Brita-in.

Mr. O. Aplin has a most interesting account of the breeding
of five pairs of the Black-necked Grebe (Podicipcs nii^ricoUis^
on a lake, the geographical position of which he most wisely
refuses to disclose. His notes contain some valuable observa-
tions on the habits of the old birds and their care of the
nestlings.

KNOWLEDGE & SCIENTIFIC NEWS.

[Jan., 1905.

Although these birds have been suspected of breeding more
than once on the Norfolk Broads, and perhaps in Ireland, no
satisfactory proof thereof has ever been brought forward.
* * «

Oyster-Catcher Swimming.

In the Irish Xaturalist for December Mr. C. J. Patten
gives a long account of an Oyster-Catcher which, on finding
itself observed when feeding along the water's edge, raced
along the beach and, taking to the water, swam out to sea for
a distance of 200 yards. Later, on its return to land, he
succeeded in heading it off and running it down, when he
found that one wing had been injured, apparently some days
previously. The bird is now in the Dublin Zoo.

ZOOLOGICAL.

liy R LVDEKKER.

BlaLck Foxes.

AccoRDi.vG to the Norfolk IW-ekly Standard of October 22,
a litter of black foxes was bred last spring in the Bedale
country, on the estate formerly belonging to the late Duke of
Cleveland. If authentic, this event would appear to be unpre-
cedented, but. as has been recently pointed out by a writer in
the Field, young foxes are normally slate-coloured, and
the statement may be based on this fact. Be this as it
may, Mr. J. E. \lillais, in the first volume of his magui-
ficent new work on " British Mammals." after mentioning
that a tendency to melanism is by no means uncommon in the
species, records only two instances of completely black foxes.
The first of these occurred in the New Forest, and is referred
to in the /Zoologist for 1890, the second was reported from
Leicestershire in 1903. The old legend that to hunt a black
fox implied certain death to the pursuer indicates, however,
the occurrence of such instances in former years. In this
connection it may be noted that a writer in the November
number of the Zoologist states that both melanistic and albino
animals are generally inferior in size to their normally
coloured fellows.

* •» *

The Fallow Deer as a British Fossil.

In the course of a paper on the contents of a Derbyshire
cavern read before the Geological Society on November 23,
the authors, Messrs. A. Bembrose and E. T. Newton, referred
to a large number of remains which they identified as belong-
ing to the fallow deer. These were stated to have been found
with those of undoubted Pleistocene mammals at all horizons
in the cavern strata. Now, fallow deer remains have hitherto
been unknown from any Pleistocene British cave ; and since
fallow deer are just the kind of animals whose carcases would
be carried into caves by hy<enas, it was argued in the discus-
sion which followed the reading of the paper that if their
remains are absent from all other cavern-fauna, they are
not likely to occur in this one. The argument is no doubt a
strong one, but if the remains are rightly identified (and this
was not disputed) it seems difficult to account for their occur-
rence among the Pleistocene remains, otherwise than accord-
ing to the views of the authors of the paper. It may be
added that numerous fallow deer remains have been described
from the peat of Denmark.

» * ♦

The WhaLles of the N.W. Atla^ntic,

Important whale-fisheries have been established of late
years on the coast of Newfoundland, and the enormous
amount of material thus made available to the naturalist has
been taken advantage of by Mr. 1'. W. True, an American
zoologist who has devoted special attention to the study of
this group of the cetacea. The results of his investigations
have recently been published at Washington by the Smith-
sonian Institution in a quarto voltnne, illustrated by no less
than 50 plates showing the carcasesof whales as they are landed
at the Newfoundland factories. Five or six different kinds of
whales are taken at the establishment, of which the great

majority (both as regards species and individuals) are rorquals,
or finners, of the genus Bnlariiopti-ra, t\ia.t is to say, whales with
short whalebone, and of a long and slender shape, adapted
for swimming at a great pace. A certain number of hump-
backs (Megapti-ra) are, however, captured, v.hile occasionally
a sperm-whale {Physiter macrocephaliis), and. still more rarelv,
a Biscay right-whale is taken. All the species met with on the
American coast seem identical with those found on our own
side of the Atlantic. The most abundant is the common
rorqual, whose scientific title {Bahfuopttra Hi«sr»/»s) the author
seeks to transfer to the " sulphur-botlarn," generally known as
B. sibbaldi. Apart from the rights of the case, such a shifting
of well-established names can have no possible advantage, and
must inevitably lead to confusion.

* * *

Deaths from Snake-Bite and Wild Beasts.

The mortality in India duo to the attacks of wild beasts and
snake-bite, according to the Government returns for 1903,
maintains its usual appalling magnitude, showing, indeed, an
actual increase in some items, although there is a decrease
under other headings. The total mortality among human
beings reported to have been caused by wild beasts during the
year was 2749, against 2536 in 1902 ; the increase being largest
in Madras (236) and the United Provinces (90). The destruc-
tion of life by tigers was, however, considerably less than
during the previous year, the number being 866, against 1046 ;
the greatest decrease in this item being in Bombay, while
Madras showed an increase. On the other hand, the deaths
from wolves rose from 338 in 1902 to 463 in 1903 ; the
great bulk of these being attributed to a few which have
taken to man-eating. The deaths from snake-bite fell from
23.167 in 1902 to 21,827 in 1903 ; Bengal alone accounting for
10,394. *^)f the remainder, 4964 deaths are credited to the
United Provinces, 201 1 to Madras, :oo8 to Bombay, 1031 to
Burma, and 1386 to the Central Provinces.
« * *

The Old Rhinoceros a.t the "Zoo."

At the time of writing these Notes, the Indian rhinoceros
presented to the Zoological Society by the late Mr. A. Grote,
on July 25, 1864, was reported to be in a moribund condition.
This animal affords a wonderful instance of longevity in
captivity. It has since died.

* * *

The First Fruits of the " Discovery's "
Voya.ge.

The first description of a new animal " discovered during
the voyage of the Discovery " is apparently one in the December
number of the Aiuuils and Magasinc of Xatural History. In this
Mr. T. V. Hodgson gives a preliminary notice of a peculiar
type of " pycnogonid," or " sea-spider," distinguished from all
its relatives by the presence of an additional pair of legs,
which brings up the number to five. On this account, although
it is admittedly very close in other respects to the well-known
Nijmphon, the new form is made the type of a genus by itself,
under the title of Pentanyinphon antarcticns.

* * *

Papers Read.

At the meeting of the Geological Society on November 23,
Messrs. Bembrose and Newton communicated a paper on the
contents of a Derbyshire cavern, to which fuller reference is
made in an earlier paragraph ; the Ammonites of the group
Lytoceratidcc formed the subject of a communication by Mr. S.
S. Buck man at the meeting of December 7. At the meeting
of the Linnean Society on November 13, Mr. G. B. Buckton
described certain hemipterous insects of the family .1/'(H;/im(ii/<j.
Captain Crawshay, at the meeting of the Zoological .Society on
November 29, communicated some notes on the liabits of the
lion ; and the sixth part of Sir C. Eliot's contributions to our
knowledge of the nudibranch molluscs of East Africa was also
taken. Mr. Lydekker, in addition to describing certain forms
of loris, or oriental lemurs, exhibited photographs of paintings
of animals in the pos.session of H. M. the King at Windsor
Castle. The other papers included one by Dr. Hagen on
certain crustaceans, one by Mr. Boulcnger and another by Mr.
Beddard on lizards, and a fourth by Mr. Gurney on South
African entomostracous crustaceans,

Jan., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

Heredity.

By J. C. SHEXSTONE, F.L.S.

It is now three centuries since " Gilbert " of Col-
chester taught us to practise the method of reasoning-
fiom observation and experiment. Since his day,
hosts of workers have attacked natural phenomena
by inductive methods, and with such success that the
present state of knowledge in chemistry and in
physics affords us reasonable ground for hoping that
before long equal progress may be made in the study
of plants and animals. It mav, therefore, interest
the readers to consider what advance has been made
in the latter branches of knowledge.

I have selected '' Heredity " as the subject of this
article because it is peculiarly identified with living
things, and because it is a subject of such importance
to the human race that it appeals to us more forciblv
than any other branch of enquirv.

The origin of our domesticated animals and of
wheat and barley are lost in antiquity; these must
have been obtained at some very remote period, by a
gradual process of cultivation and artificial selection
from wild animals and wild plants, the varieties
best suited to man's requirements having been selected
for the production of the food supplies required by
early men. We also find the ancestry of men care-
fully traced in the Biblical and other very early re-
cords; we may therefore conclude that heredity at-
tracted attention as far back as history carries us.
But the knowledge of our ancestors was confused with
much error, and no solid advance towards discovering
the principles of heredity was possible until the great
Swedish naturalist, Linnaeus, had classified and ar-
ranged all known forms of plants. Linnaeus was the
first to realise the discord and confusion which ex-
isted in our knowledge of plants and animals until
his time. And he clearly perceived that there must be
a natural system which, however, could not be de-
termined until the rules underlying Nature's own sys-
tem had first been discovered. In order to enable
students to search for these rules, he described and
classified provisionally all known forms of plants.
His system was, it is true, an artificial system; it was
not founded upon actual relationship existing amongst
the members included in his various groups, never-
theless it enabled naturalists to clearly indicate any
particular plant to which their investigations referred,
and thus removed the great difficulty which had previ-
ously existed of communicating botanical knowledge,
and opened the way to solid advance towards a com-
plete knowledge of plants and animals.

-'Vfter Linnaeus, progress was slow, clogged by the
dogma known as the "constancy of species": the
belief that every form of animal and plant owes its
existence to a special act of creation. For at least a
century this dogma remained as an article of faith
which no naturalist could doubt without losing his
scientific reputation, and the belief was strengthened
by the fact that it accorded with the tenets of the
Churches. This is all the more astonishing when we
remember that breeders of animals had long been
skilled in moulding their forms to suit the require-
ments of man, and that the variation of vegetables by
cultivation had been practised from a period preced-

ingr the advent of Linnteus, the varieties of vegetables,
of fruits, etc., being in fact increased aim st daily be-
fore everyone's eyes, by processes of cultivation. The
skill of the early pigeon-fanciers affords a good illus-
tration; and one has but to tell the history of the culti-
vation of the rose, to show how inconsistent this dog-
ma was with the facts which stare everyone in the
face; for we find that whilst Parkinson, one of the
earliest writers (1629) upon gardens, only speaks of
the red, the white and the damask roses, and Gerard,
at the end of the sixteenth century, describes eighteen
varieties, John Ray in the seventeenth mentions
thirty-seven, whilst a century later no less than
seventy-nine varieties were in our gardens; quite early
in the nineteenth century the number of varieties of
the rose had risen to above two thousand, and to-day
they are so numerous that it would be impossible to
draw up a complete list. The mania which existed,
during the seventeenth century and later, for pro-
ducing new varieties of tulips by cultivation, affords
an equally forcible illustration. Many of these varie-
ties of plants were undoubtedly produced by
hybridization; but as any attempt to change the forms
o{ animals and plants was held to be a breach of the
.Almighty's law, these new varieties were frequently
introduced to the public as new plants imported from
foreign countries, thus hiding the real facts from
the eyes of the public. These historical facts show
us how strongly the dogma of the " constancy of
species " had become rooted, and perhaps the greatest
debt we owe to Chas. Darwin is the destruction of
this dogma which had blocked all progress.

I must now introduce to the reader. Christian Kon-
rade Sprengel (1750), for a time rector of Spandau,
who, noticing that the honey in the wood cranesbill
was hidden by inconspicuous hairs at the lower part
of the petals, suggested that the hairs might serve
to protect the honey from rain whilst leaving it ac-
cessible to insects, an observation which led him to
conclude that honey is secreted by flowers for the sake
of insects, and ended in his becoming so absorbed in
studying the relationship of flowers and insects that
he neglected his duties as rector, was removed from
his post, and lived thereafter neglected and shunned
by men of science as a strange, eccentric person. The
book which he published upon plants and insects* met
with so little support that he never brought out a
second volume. Many years later Chas. Darwin was
inspired by this work to investigate the subject, and
his investigations resulted not only in considerable
additions to Sprengel's work, but led to the complete
knowledge of the .sexuality of plants, a subject little
understood until towards the middle of the last
century.

The organs of a flower consist first of a seed vessel
containing the undeveloped seed. At the apex of this
seed vessel is a viscid surface called the stigma, some-
times, but not alwavs, provided with a stalk. Secondly,
of certain little bags of golden dust, the anthers,
with which we are all familiar. Tlie yellow granule.s
of which this dust is composed, if they reach the viscid
apex of the seed vessel, send minute tubes down to
a cell called the "germ-cell" in the young seed and
thus fertilise it. Unless the young seed is fertilised,
it never matures but presently fades away and dies.
{To be continued.]

•Das entdeckte Geheimniss der Natur in Bauc und in der

Befruchtung Bhimen, 179.3.

KNOWLEDGE & SCIENTIFIC NEWS.

[Jan., 1905.

REVIEWS OF BOOKS.

The Mood. — "A Summan- of the Recent Advances in our Know-
ledge of our Satellite, with a complete photographic atlas,"
by William H. Pickering, of Harvard College Observatory.
(John Murray. Price £z 2S.)

It is the declared intention of the author of this
sumptuous volume to give an account of some of the
more recent advances in our knowledge of the moon, and
to leave to the text-books a statement of that earlier
acquired information with which most people are already
familiar. This statement of Professor Pickering's intention is
not quite fair to his accomplishment ; because it might lead the
reader to suppose that the book contained only such material
as had been already presented in the author's contributions
to the Har\-ard Observatory Annals, whereas the book might
best be defined as a brilliantly interesting essay on the
moon, coloured or supplemented by Professor Pickering's
views of the inferences to be drawn from the latest informa-
tion concerning it. Thus the first three chapters, written in a
vein which will appeal to any intelligent and educated person,
comprise the commonly accepted views as to the origin of the
moon, the data in regard to its distance, rotation, libration,
&c. ; and the opinions formed within the last few years by
many astronomers on the probable density and temperature
of a lunar atmosphere. Some of the new views arc hypotheses ;
some are of a nature more solid than that and are based on
the Harvard " discoveries " which the splendid Arequipa
station have enabled astronomers to add to the common
capital of astronomic science. In another particular new
•' views " of the moon are presented, for the volume contains a
complete photographic atlas of the moon, the plates of which
cover the whole visible surface of the moon five times. Eulogy
of these beautiful plates is superfluous ; they h.ave been made,
and they have been selected and printed, with one object alone
in view, which is that the Harvard College Observatory, and
the expedition which it sent out to Jamaica in 1899 for the
special purpose, should have the honour of presenting the most
complete and the most scientifically useful set of photographs
of the moon in existence. With, or (as Professor Pickering's
opponents might say) without, some of the deductions which
are drawn from his examination of the moon's surface, they
mark a fine achievement, and are an enviable possession.
There are nearly a hundred plates in all ; and they con-
stitute the only complete lunar atlas in existence. The
first point on which Professor Pickering may be said to
invite controversy is in respect of the moon's atmosphere,
water and temperature. He gives observational grounds
for believing that an atmosphere exists at the moon's surface,
comparable in density to that which would be found at a
height of about 30 to 40 miles above the surface of the earth.
A haze, he adds, appears to rise to a height of about three or
four miles on the sunlit side of the moon. Accepting Professor
Pickering's observations as accurate, what is to be said of his
explanation that water and carbonic acid gas are escaping from
the moon at such a rate as to constitute an atmosphere of the
kind he predicates, or to give rise to permanent snow fields ?
The opposed view is that the gases in question would escape
too quickly from the moon's surface — the force of gravity there
being insufficient to retain them — and that some other expla-
nation must be found. Professor Pickering's hypothesis, while
explaining with apparent satisfaction that the observed enlarge-
ment of the white spots of Linnc towards lunar sunset and
during a lunar eclipse are due to a sublimation of hoar frost, is
peculiarly difficult of application to the systems of bright streaks
which radiate from some of the lunar craters, and which are
attributed to snow produced by allied causes. Similarly
Professor Pickering, from the consideration of the darkening
of certain areas of the moon's surface and their increase of
size during the lunar morning, together with their dis.appear-
ance towards the time of sunset, arrives at the conclusion
that a luxuriant vegetation springs up on the moon, nourished
by water which it derives by capillary forc<; from the soil and
fostered by the sun's heat to a giant growth that is aided by
the small gravitational attraction of the moon itself. Against
this hypothesis, fascinating but fanciful, we have to set the fact
that no terrestrial life exist ■; on terrestrial mountains 20,000 feet
or more above the sea under atmospheric and thermometric

conditions which must be vastly more favourable than
those to be found on the moon. Furthermore, as another
writer has said, whatever may have been the circum-
stances which led to the beginning of life on this earth,
they were evidently of rare occurrence. The fate of
the moon as a habitation for any form of life, as we
know it, was probably in large part determined by the ratio
between its gravitative force and the energy of the kinetic
movement of the gases which constituted its atmosphere. If
that energy had been suflicient to keep them on the satellite,
there is no reason why it should not have had the history of a
miniature earth. These postulates are palpably non-admissible,
and it is most reasonable to suppose that the moon has not
even vegetable life as we know it. These are, however, only
" spots on the moon," and we should not be justified in reg.ard-
ing them as such, were they presented with any less appear-
ance of incontrovertible and established truth, in a volume
which is not a controversial work at all, but is clearly intended
to inform the growing class of people who, without being
experts, are deeply interested in science. If, however, they
bear in mind that — to adopt an .Vmerican expression — all Pro-
fessor Pickering says does not " go," then in buying and read-
ing this fine work they will be richer by the knowledge of in-
genious, interesting, and fascinating theories, as well as by a
solid possession of great instructional value.

Game, Shore, and Water Birds of India, with additional refer-
ences to their allied species in other parts of the world, by
Colonel A. E. Le Messurier, C.I.E., F.Z.S., F.G.S., fourth
edition (London : Thacker and Co., 1904). Works on the
birds of India are not numerous, and sportsmen, as a rule, have
found them either too bulky or too technical. That is to say,
these works have been designed rather for the ornithological
student than the campaigner. Though the standard, in short,
of these tomes has been an unusually high one, they are not
adapted to the use of men who must travel with as little
luggage as may be. Colonel Le Messurier was one of the
first to realise this, and so far back as 1874 he prepared a
volume, for private circulation only, on the " Game Birds of
the Eastern Narra." I-"our years later — in 187S — this book
was issued to the public with some slight additions. This year
was made memorable in the annals of Indian Ornithology by
the appearance of the first volume of Hume and Marshall's
•' Game Birds of Indii," a work which quickly made its in-
fluence felt. Colonel Le Messurier was among the first to
realise the sterling value of these volumes, and we find, indeed,
that in his next edition he begs to acknowledge that the addi-
tions therein made are largely taken from this source. That
the author's efforts to produce a handy and portable guide for
the use of sportsmen were fully appreciated may be gathered
from the fact that a fourth edition has been called for. It is
highly probable that this last will meet with as cordial
a welcome as the earlier volumes ; inasmuch as all the
features which secured success for the earlier editions
are preserved here, and considerable additions have been
made. Viewed, however, from an entirely impartial stand-
point, it must be admitted that a great opportunity has
been missed in this new voltnne. There can be no doubt but
that the introduction reqtiiresdrastic alterations. As it stands
it is useless alike to the scientific student and to the sports-
man, and errors are painfully common. The classification
adopted is antiquated. The quotation from Professor Kitchen
Parker — unacknowledged, though placed within inverted
commas — was more or less true when he wrote it in 1875. But
in 30 years much has been done in this matter. On the ques-
tion of migration, the author relics almost entirely on Professor
Newton's masterly article in the ninth edition of the " Itncyclo-
pccdia Britannica." But, as touching the mysterious irrup-
tions of Pallas's sand-grouse into Great Britain, we would
gather that the last of these occurrences took place in 1872!
Other equally important matters are treated in the same
perfunctory m.anner. Under a double heading, of ponderous
capitals, the question of" Extern.al Variation in the Two Sexes
and at Different S(;asons" isdiscusscd, and dismissed, in (hree
paragraphs of two lines e.ich ! The subject of nidification is
dealt with in 16 lines ! L'nder the curious plea that, "owing
to the facilities of travel, Anglo-Indians are now engaged in
most countries either in business or pleasure," the author, in
this edition, includes references to "all species in other parts
of the world that are allied to the game, shore, and water
birds of India." Surely even Anglo-Indians cannot contrive

Jan., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

to be in more than one country at one time, and since we pre-
sume their journeys are more or less premeditated, we cannot
see why the author should not leave them to select the appro-
priate books for themselves. His own volume will certainly
prove but a broken reed to trust to. It is a pity that matters
utterly outside the scope of this book should have been intro-
duced. So far as the sportsman's side is concerned. Colonel
Le Messurier's t^uidance will be confidently followed, for he
unquestionably knows his subject. But there can be no doubt
that those parts which are admittedly compiled from abstruse
scientific treatises, or from the labels in the Natural History
Museum at South Kensington, should be ruthlessU' suppressed.
When they are not inaccurate, and out of date, they are out
of place, and worse than useless, because they take up valuable
space. An introduction giving a summary of the varied geo-
graphical features of India and the peculiarities of the avi-
fauna of the several regions which may be distinguished
would have been of immense help. To this might have been
added the observations which Colonel Le ^iessurier must
have made in the habits of birds and their relation to the
environment. To those about to enter upon civil or military
life in India such a chapter would be helpful indeed. A
collection of native legends and superstitions concerning the
birds of India would have still further added to the value and
usefulness of this book. We hope ihat these things may yet
be done. This work is profusely illustrated, but on the whole
the figures are about as bad as any it has ever been our lot to
criticise. These remarks are made in no spirit of captious
criticism, but with a view to make of this work a really valu-
able, up-to-date guide to the "Game" Birds of India.

"The Cambridge Natural History " (Fishes, Ascidians, Sec.)-
by Various Authors (Macmillan and Co., Limited; price,
17s. net). We have the greatest satisfaction in welcoming the
somewhat belated appearance of this long-expected volume,
as a trustworthy and up-to-date work on fishes written on
more or less popular lines was a desideratum. On the whole,
this volume, which is bulkier than any of its fellows, may be
said to fulfil what was expected of it ; although portions of it,
owing to having been set up in type for a considerable time,
are a little out of date ; and there is a certain amount of dis-
advantage attending the dual authorship of the portion
devoted to fishes, as it is difficult to ascertain to what extent
each of the two eminent contributors is responsible for, and
approves of, the general sj'stematic arrangement of the
members of the class Pisces. Before going further, it should
however, be mentioned that the relegation of the sections
dealing with the lower chordates to authors other than those
responsible for the fishes was quite a proper, and indeed
essential, proceeding ; and we may congratulate Professors
Harmer and Herdman on the very excellent and exhaustive
manner in which they have severally treated their sections of
the subject. .'Vs regards the fishes, while Professor Bridge, of
Birmingham, has undertaken the morphological part of the
subject together with much of the systematic work, the
taxonomy of the modern bony fishes and their immediate
extinct relatives has fallen to the share of Mr. Houlenger, the
fish-expert of the British Museum. His rearrangement of
these fishes (which has already been published in the Annals
and Maf:;azinc of Nalui-nl History) considerably modifies pre-
vious conceptions as to the mutual relationships of some of
the groups, and may be regarded as a distinct advance in
systematic natural history. As a small instance of the
want of uniformity due to divided authorship, we may
refer to the two family names Ostcolepitia- and Lcptokpidida:.
As regards Mr. Bridge's contribution, it cannot fail to be
noticed that the morphological side receives much fuller treat-
ment than is accorded to the systematic section — a by no
means unmixed advantage, we venture to think, in what is sup-
posed to be, in great measure, a popular work. The chief feature
in the taxonomy whereby this part of the work differs from
many treatises now in use is the inclusion of the chimaeras and
their allies (Chimceroidci) in the same group with the sharks
and rays (Elasmohranchii). The essential difference in the
structure of the skull of the two groups is, in Mr. Bridge's
opinion, an adaptive feature, due perhaps to the great deve-
lopment of the structures which serve the function of teeth in
fishes of this group. We are inclined to think that the author
maybe right in his view; and we should be still more disposed
to endorse his scheme if the chimaeroids were not such an
ancient group. In the suppression of the term Actinopterygii

for the whole of the fan-finned tcleostomous fishes, as opposed
to the group Crossopicry^ii for the bichir and its relatives, we
cannot think the author (or authors ?) has been well advised.
Moreover, we regret to see the familiar name Cestracioii of the
Port Jackson shark displaced by Hetcroihmics, especially as
we ourselves consider the use of the latter term barred by (he
existence of the name Heterodou. As a whole, however, we
cannot but express our opinion of the high scientific value of
the latest volume of the excellent Canihrid^^c Satural History.

" A Later Pepys," by Alice C. C. Gaussen (John Lane, 2 vols.).
There was another Pepys, who followed him, and who, in the
opinion of his time, as well as of his polite friends, was a much
more distinguished person than the immortal Diarist. He was
Sir William Pepys, Master in Chancery, born in 1740, and by
reason of his great literary abilities, and his personal charm,
the associate and correspondent of many who formed what we
should call the literary circle of the latter part of the eighteenth
century. His letters to Hannah More, Mrs. Montagu, Mr.
James McDonald, Major Rennell, Sir Nathaniel Wraxall,
have been preserved, and, collected in these volumes, form a
very interesting and valuable record of the thoughts, manners,
and conversation of these times. We should, perhaps, say
now that Sir William was flattered by knowing " the best
people " ; but if he was proud of their intimacy and converse,
they were no less proud of his, for he seems to have been
emphatically one of those Men of the Time who, like othersin
our own day and generation, create an impression that much
higher achievement was in their powers than they ever put
forth their energies to grasp. However that may be, Sir
William Pepys was a distinguished, amiable gentleman, to
who.se accomplishments his biographer's handsome volumes do
ample justice. The only fault we have to find is that the
letters, instead of being arranged chronologically, are grouped
under the persons to whom they were addressed.

Who's Who. — One might say of the yearly publication of
" Who's Who " (A. & C. Black), as already has been said of
London's service of messenger boys, that we cannot imagine
how the world ever managed without it. It is as indispensable
to the journalist or the man of business as a rhyming diction-
ary is to a poet, or a "The.saurus" to a neophyte in letters,
and we feel something of the same gratitude for its unfailing
readiness to supply information as we experience towards
such benefactors of the public as the postman or the City
policeman. It is, to speak seriously, an extremely useful and
an extremely well-edited work; it contains 17,000 biographies
on its 2,000 pages, and it is, take it for all in all, the cheapest
sevenand-sixpenny-worth that is published. It is the Bio-
graphical Directory of the working professional man.

Whitaker's. — There is no new thing to be said of " Whitaker's
Almanack," which, with the neat, concise, and handy " Whit-
aker's Peerage," makes its unfailing appearance at this time
of year, for even if one were to say that it possesses several
new features this year, one would but be repeating an observa-
tion which is true of it every year. Speaking from the point
of view of a scientific review we should welcome a little more
attention to science, or to the scientific aspects of industry,
among its able summaries. But one cannot expect every-
thing within its covers ; and the information which is given is
remarkable for its usefulness, its universality, its just propor-
tions, and its unblemished accuracy.

The Englishwoman's Year Book.— This is a publication
which, like -'Who's Who," is published by Messrs. A. & C.
Black, and is gaining for itself with some rapidity the same
position of indispensabihty. Nothing that concerns women,
especially working women, is alien to it ; and wc can sug-
gest no improvement beyond the addition of a more charac-
teristic calendar. The calendars, we think, might well em-
brace the birthdays of famous women.

X-Ray and Electro-Physical Apparatus. — Mr. A. C. Co.ssor, of
54, Farringdon Road, has sent us a copy of his recently-issued
list, covering the various specialities manufactured by him.
Beyond X-ray and allied apparatus the catalogue comprises
many articles of use or interest to the worker on the physical
side of science. We are glad to notice that there are several
scientifically trained assistants on the staff of the firm, the
importance of which cannot be overrated where the require-
ments of modern science are to be successfully carried out.

KNOWLEDGE & SCIENTIFIC NEWS.

[Jan., 1905.

Conducted hi/ F. Shii.lington Scales, f.r.m s.

Royal Microscopical Society.

XovEMBER i6th, Rt. Hon. Sir Ford North, F.R.S., in
the chair. Mr. Rousselet described two old micro-
scopes which had been presented to the Society by
Mr. C. L. Curties. The first was a copy by Doilond
of Cuff's " New Constructed Double Microscope,"
designed by Cuff in 1744, in which the body was moved
instead of the stage, the latter being customary in
microscopes of later date. The second microscope
was a copy of " Jones' most improved compound
microscope," made and modified by Banks, between
i8ii and 1820, though the invention of this type dates
from 1798. Mr. Hugh C. Ross, R.N'., exhibited and
described a new electric warm stage of his invention.
It consisted of a flat plate or box of ebonite about
3 inches long, li inches wide, and f inch thick. A
coil of wire offering a standard resistance was pressed
into the ebonite box and covered in w-ith a sheet of
mica. The ebonite box rested on the slide, mica side
downwards, and a gap i inch square was left in the
centre of the stage so as not to interfere with the
examination of the object. A Nernst lamp served
both as iliuminant and regulator of the current to the
warm stage. It was claimed that this warm stage,
being used above the slide, did not interfere with the
focus, could be used with the highest powers, allowed
the use of a condenser, did not interfere with the move-
ment of the mechanical stage, and was self-acting.
Mr. C. L. Curties exhibited new designs of Nernst
lamps suitable for use with the microscope for currents
of 100 and 200 volts respectively, and fitted with
ground or blue glass fronts. Mr. Conrady read a
paper on " Theories of Microscopic Vision. A vindica-
tion of the .Abbe Theory," which contained some new
views on the suhjfrt.

The Quekett Microscopical Club.

The 417th Ordinary Meeting of the Quekett Micro-
scopical Club was held on November i8th at 20, Han-
over Square, W., the President, Dr. K. J. Spitta,
V.P.R.A.S., in the chair. Mr. A. E. Smith exhibited
a number of large transparencies, prepared from his
own photo-micrographs. Notes by Mr. A. E. Merlin,
F.R.M..S., " On a suggested modification of Rousse-
let's Live Box " and " A supplementary note on the
foot of the House Fly " were, in the absence of the
author, read by the Hon. Secretary. In the first note
Mr. Merlin, after paying tribute to the manifold ad-
vantages of the Rousselet Live Box, alluded to the
fact that the comparatively rapid evaporation of the
water film prevented any prolonged observation of
minute organisms such as monads, &'C., under high
powers. If, however, the cover-glass is cemented to
the flange instead of being screwed in, and if a rubber
band is slipped round the junction of the box and the
carrier, a practically airtight joint is formed, and
evaporation proceeds so slowly that he had been able
to keep an object under observation for several days.

Mr. Merlin's second note was a continuation of two
previous papers on the same subject read before the
club in 1S95 and 1S97. He now reported that he had
succeeded in detecting a small knob or protuberance on
the side of the sickle-shaped terminal appendages of
the hairs of the pulvillus, which knob, in his opinion,
marked the position of the aperture through which the
viscid secretion was poured out. He h.id not, how-
ever, been able as yet to detect the aperture with the
highest optical power at his disposal, viz., i" apochro-
mat by Zeiss of N.A. 1.427 and a 40 compensating
ocular. Even with this magnification the image of
the sickle filament was sharp and clear.

Mr. A. E. Conrady, F.R.A.S., F.R.M.S., then gave
a rtsume of his important paper " Theories of Micro-
scopical \'ision — a Vindication of the .Abbe Theory,"
which had laeen read before the Royal Microscopical
Society on the previous Wednesday.

Micro-photographs.

The term micro-photograph is used in England to
distinguish minute photographic reductions of larger
objects in contradistinction to photographs of enlarge-
ments of microscopic objects which have been magnified
by means of the microscope, and which arc known as
photo-micrographs. In the " Photographic Reference
Hook " for 1904 an account is given of the method of
preparing such micro-photographs, of which the follow-
ing brief resume may be of interest. They require
considerable patience and skill, as the image is so
minute that the operations of development, &-c., must
be carried out in the field of a magnifier or small micro-
scope. Most of these photographs are made abroad,
and the collodion process (wet plate) is used, or
collodio-albumen may be employed. The collodion
used for making the plates must be structureless or the
magnified images will have a reticulated appearance.
Pyrogallic acid is preferable to iron sulphate for de-
velopment, as it gives a much finer deposit. The
process consists in making a positive by copying an
illuminated negative, using a one-inch microscopical
objective for this purpose. Mr. Hislop has devised a
suitable apparatus, which is described in Mr. .Sutton's
" Dictionary of Photography." It consists of a rigid
mahogany board about six inches wide and three feet
six inches long. At one end two uprights are fixed,
between which a miniature camera, fitted with the
microscopical objective, can be moved up and down so
as to allow it to be placed opposite the negative to be
copied. A brass tube projects from the camera to-
wards the negative, to carry the objective, and is fitted
with stops of different sizes. The exact focus must be
ascertained carefully by means of a strong magnifying
glass. The negative is placed in a frame at the re-
quired distance on the long mahogany board. The
illumination may be natural or artificial, but must, of
course, pass through the negative, whilst the variations
of light, negative, and pk.te, render it impossible to
give any idea of exposure. It will generally be found
that the visual and actinic foci do not coincide, and
this must be determined by experiment and allowed for,
so that a fine adjustment becomes necessary. After
exposure the little plate is placed under a low power
microscope, in yellow light, and a few drops of de-
veloper poured over it, development being carefully
watched through the microscope, remembering that a
transparency is required, and, therefore, greater density
than otherwise should be obtained. After fixing and
drying, and before mounting, the tiny plates should be

Jan., 1 905 .J

KNOWLEDGE & SCIENTIFIC NEWS.

examined through a lens of about the same power as
they are intended to be viewed through, in order to see
whether they are worth proceeding with. The photo-
graphs are then cut into small squares with a diamond,
and can be mounted direct on to slides of the ordinary
form or to the flat end of the small Stanhope lenses, to
which they are generally attached. The slide or the
Stanhope lens must be warmed, and the mounting
medium is Canada balsam. Care must be taken that
the contact is perfect, and that the slide is free from
either air-bubbles or dust.

Ne^v Regulator for CaLmbridge
Embedding-Bath.

The Cambridge Scientific Instrument Co. have
brought out a new regulator for their well-known and
most convenient embedding-bath, which does away with
the former mercury regulator with its failings. The new
regulator was primarily designed to utilize an ordinary
paraffin lamp, where gas is not available. The hot air
travelling up a short chimney heats the water in the
bath. Suspended over the chimney by a lever is a
plate of brass serving as a sort of lid. This lever is in
contact with a bar of aluminium which is enclosed
inside the bath, and is stayed between similar bars of
nickel steel in such a way that it can only move
laterally, and in so moving raise or depress the

111

lever according to variations in temperature of the
bath. Any such movement of the lever therefore alters
the position of the lid, and consequently regulates the
amount of heat transmitted to the bath. Provision is
made for the primary adjustments. Though originally
arranged for a lamp (as illustrated) I think it would
be equally effective with a small burner, and I believe
the makers have adapted it accordingly.

I would like to call attention to the fact that the
Cambridge Scientific Instrument Co. have just reduced
the price of the improved 1900 model of their well-
known Rocking Microtome to £3 iss., and have with-
drawn the older model altogether. For cutting serial
paraffin sections this microtome has now a European

reputation, and needs no recommendation. It i^ in ii^c
in probably every large English laboratory, and the
reduction in price should largely increase its use by all

classes of workers.

Journal of the Quekett Club.

1 he half-yearly issue of the Journal of Quekcll Micro-
scii/>ical Club, dated November last, contains the follow-
ing papers : — " The Genital Organs of Taenia sinuosa,"
by Mr. T. B. Rosseter (illustrated); " .Some New .Sense
Organs in Diptera," by Mr. W. Wesche (illustrated);
the description of two new British Water-mites, by
Mr. C. D. Soar, and a list of the Spiders of the
Erigone group, by Mr. F. P. Smith. None of these
papers lend themselves to review, but the Proceedings
of the Club contain a rtsiimk of an interesting lecture
by Dr. E. J. Spitta on suiting screens for photo-micro-
graphy of stained bacteria in order to increase con-
trast, with reference to the value of the light for photo-
graphic rather than visual purposes. Dr. Spitta had
tested by means of a spectroscope the behaviour of
various orthochromatic plates to light of different
wave-lengths, and his paper is illustrated by a plate
showing the result, which deserves careful study by
photo-micrographers.

Notes and Queries.

Mounting Volvox, Larvae of Water Insects, &c.

Mr. F. T. Perks, of Denmark Hill, would be glad to know
if there is any method of mounting Volvox, LarvEE, &c., so as
to preserve their natural colour. The ordinary methods of
mounting certainly fail to do this, and most zoologists would
either examine the objects alive or stain them in such a way
as to bring out some special feature. So far as the larvae are
concerned I think they might be narcotized by cocaine, then
killed with a J per cent, solution of osmic acid, and mounted
in 2i per cent, solution of formalin accordmg to Mr. RoLisselet's
method for Rotifera, but I could not say whether this would
prove practicable with Volvox, which is a particularly difficult
object to mount satisfactorily so as to show all the structure.
Full particulars of Mr. Rousselet's methods have been
frequently published; there is a very full account in Cross and
Cole's " Modern Microscopy." Perhaps Mr. I'erks will let me
know the result of his experiments, or I should be glad of sug-
gestions from other readers.
Use of the Petrological Microscope.

Mr. J. F. I\. Green wishes to know of a book dealing with
the use of the petrological microscope. There is unfortunately
no book dealing with the subject from the microscopic stand-
point, even the largest works being strangely silent on the
matter. In the "Annual of Microscopy" for lyoo I
endeavoured to deal with the fundamental principles of the
subject in an article entitled "The Practical Applications of
the Polarizing Microscope," to which I may perhaps refer my
correspondent if he requires a brief rhumc of the subject. For
further information he might read Groth's " Physikalische
Krystallographie," or Dana's " Textbook of Mineralogy," or
Rutley's " Study of Rocks," and Cole's " Practical Geology,"
which deal with the petrological and geological side, and inci-
dentally touch on the microscopical methods. I must warn
him, however, that the subject is one that requires study if it
is to be of practical service in petrology or crystallography.

Echinus Spines. ^

Rev. W. Hamilton Gordon, Fareham.— Mr. Alfred Ueatn,
of Bury St. Edmunds, who kindly sent me the spines, informs
me that they are Echinus sphara, and that he found several of
them on the coast at St. Osyth, a village between Clacton-on-
Sea and Brightlingsea.

[Communications and enquiries on Microscopical matters are invited,
and shouU be addressed to F. Shillington Scales, ''Jersey, St.
Barnibas Road, Cambridge.]

KNOWLEDGE & SCIENTIFIC NEWS.

[Jan., 1905.

The Face of the Sky for January.

By W. Shackleton, F.R.A.S.

The Sun. — On the ist the Sun rises at 8.S, and sets
at 4.0 ; on the 31st he rises at 7.42, and sets at 4.45.

The earth is nearest the Sun on the ist at 5 a.m., hence
he attains his ma.ximum apparent diameter of 32' 35".

Sunspots, facula;, and prominences are very numerous ;
at the time of writing there are several fine groups of
spots almost stretching from limb to limb, which define
the spot zone most conspicuously.

For plotting the positions of spots, &.C., the following
table may be used : —

Date.

Axis inclined from N.
point.

Equator N. of
Centre of disc.

Jan. I . .
,, II ..
,, 21 ..
.. 31 ••

2° I'E.
2° 52' W.
7° 33' W.

11° 55' w.

3° 13'
4° 19'
5° 17'
6' 4'

The Moon

—

Date.

Phases.

Jan. 5 ..
.. 13 ••
„ 21 ..
.. 28 ..

• New Moon
J) First Quarter
0 Full Moon
d Last Quarter

6
8

7
0

17 p.m.
II p.m.
14 a.m.
20 a.m.

OccuLTATioNS. — The following occultations of the
brighter stars are visible at Greenwich.

Name.

Disappearance.

Reappearance.

Dale.

Angle from

Mean
Time.

Ver-

V.^r-

point.

tex.

point.

tes.

p.m.

Jan. 10..

6 Aquarii ..
B.A.C. 1526

■f4

5 9 45°

,1°

6.2,

26s<>

240'

•• 'Z- •

.V8

9-40 37°

28°

10.36

,06°

284"

130 Tauri..

r-i

5-58 103°

U2'

7-1

240=

276"

.. 19..

36 Geminonim . .

4-51 i^*'
a.m.

180°

5.24

213°

254'

.. 24..

p Virginius

3-8

0-43 1 145°

I74»

1.40

setf"

281"

The Planets :— Mercury.— Towards the end of the
month Mercury is a morning star in Sagittarius, being
at greatest elongation of 24=' 28' W. on the 22nd, when
he rises at 6.24 a.m.

\'enus is the most conspicuous object in the evening
sky looking towards the S.W., and sets about 4 hours
after the sun. The planet is increasing in brilliancy, and
can readily be seen when on the meridian in broad day-
light ; the time of meridian passage is 3.5 p.m. and is
very nearly the same on each day of the month, whilst
the meridian altitude increases from 23 on the ist to 37^'
on the 31st. The apparent diameter of the planet on
the ijtii is i'i"-2 ; the disc appears slightly gibbous, 0-65
being illuminated.

.Mars does not rise until after midnight.

Jupiter is on the meridian shortly after sunset, and
remains above the horizon until midnight. In conse-
quence of increasing distance from the earth, the planet
is diminishing in lustre; the apparent equatorial diameter
is 4o"-5 on the i6th, whilst the polar diameter is 2"-6
smaller. The planet is in quadrature on the 12th.

The following table gives the phenomena of the satel-
lites visible in this country.

i ■

1 1 I'-M-'s.

t/2 C H. M.

P.M.'s.

1 ^^■>^-

II. Ec. R. 6 13

Oc. D

7 I

Ec. R. 6 57

I. Oc. D. 10 37

III

Tr. I.

8 S2

Oc. D. 8 57

■5

I. Tr. I. 7 45

Ec.R.

10 32

III

Ec. D. 8 41

I. Sh. I. 9 6

Tr. E.

II 6

ITI

Ec. R. 10 12

I. Tr. E. 9 59

Sh. I.

5 31

Tr. E. 641

I. Sh. K. II iS

Tr. E.

6 23

Sh. I. 6 49

1. Oc. D. 5 5

Sh. E.

7 43

Sh. E. 9 18

III. Tr. E. 7 5

II.

Oc. D.

6 18

Tr. I. 8 3

I. Ec. R. 8 37

II.

Oc. R.

8 50

Sh. I. 9 22

III. Sh. I. 10 29

II.

Ec. D.

9 3

Tr. E. 10 17

I. Sh. E. 5 47

III.

Ec. R.

6 II

Ec. R. 8 53

II. Tr. I. 9 29

Sh. E.

6 40

Sh. E. b 3

II. Oc R. 6 13

Oc. D.

SSV

III.

Oc. D. 7 8

II. Ec. D. 6 26

Tr. I.

6 b

Ill,

Oc. R. 9 24

II. Ec. R. 8 50

Sh. I.

7 2b

I. Tr. I. 9 40
I. Sh. I. II 2

Tr. E.
Sh. E.

8 19

9 39

'* Oc. D." denotes the disappearance of the Sitellile behind the disc, and
"Oc. R." its re-appearance; "Tr. I." the ingress of a transit across the disc,
and "Tr. li." its egress; " Sh. I." the ingress of a transit of the shadow across
the disc, and " Sh. E." its egress.

Saturn is diminishing in brightness, and is only observ-
able for a short time in the S.W. after sunset. The plane
of the ring is inclined to our line of vision at an angle of
14''; hence the ring appears well open.

Uranus is unobservable.

Neptune souths at 1 1.45 p.m. on the ist and at 9.44 on
the 31st. He is situated in the constellation Gemini and
can readily be found by reference to m Geminorum.

Right Ascension. N. Declination.

Neptune (Jan 14) . 6*^ 27"" 19^ .. 22° 16' 33"

M Geminorum . . 6'' 17"' 13^ . . 22° 33' 36"

Meteor Showers : —

Jan. 2-3 XV.Ii2o"i| + 53 Quadrantids

,, 17 IxiX.h 4ml + 53 I OCygnids

Swift ; long paths.
Slow ; bright.

The Stars : —

Minima of Algol occur between sunsetj and midnight
on the 13th at 10.37 p.m., i6th at 7.26 p.m., and 19th at
4.14 p.m.

0 Ceti (Mira) should be watched, as it will probably
reach a ma.\imum next month, when observation will be
difficult on account of daylight.

Telescopic Objects: —

Nebula;. - -Orion Nebula, situated in the sword of
Orion, and surrounding the multiple star ", is the finest
of all nebuhi-; with a 3 or 4 inch telescope, it is best
observed when low powers are employed.

Crab Nebula (M i), in Taurus, situated about lA^
north-west of f Tauri in R.A. 5h. 29m., Dec. 21" 58' N.

Clusters. — M 37, situated in .\uriga, is one of the
finest clusters, and very compact ; its position is R.A.
5h. 46m., Dec. 32" 32' N.

Double Stars. — P Orionis (Rigel), mags, i and 9. sepa-
ration 9". f)n account of the brightness of the principal
star, this double is a fair test for a good object-glass of
about 3-inch aperture.

S Orionis, mags. 2 and 7, separation 53" ; easy double.

f Orionis, triple, mags. 3,6, and 10, separation 2"-5 and
56" ; rather difficult in a 3-inch telescope.

^ Orionis, mags. 4 and 6, separation 4"-5 : pretty
doulile.

" Orionis, triple, mags. 4, 8, and 7, separation i2"-5and
42."

UDOdiledge & Selentilie Hems

A MONTHLY JOURNAL OF SCIENCE.

Conducted by MAJOR B. BADEN-POWELL and E. S. GREW, M.A.

Vol. II. No. 2. [new series.] FEBRUARY, 1905.

r Entered at -i
LStationers' Hall. J

SIXPENCE.

CONTENTS.—See Page VII.

EditorioLl.

.\t the end of the Prst year of the New Series of
" Knowledge," it will not, perhaps, appear superero-
gatory to review the progress of the journal since its
amalgamation with the " Illustr.\ted Scientific
News," from a material as well as from an editorial
standpoint. It was intended in the amalgamation to
preserve and present the features of both periodicals ;
that is to say, while the editors were determined that
there should be no falling off either in the amount or
the value of those contributions to Astronomic and
Natural Science which had, up to that time, formed
the chief contents of " Knowledge," they also be-
lieved that it was desirable to effect a general re-
arrangement of the periodical, and to add to it articles
on Physics, Chemistry, and Applied Science. The
reason for this belief was not alone that they thought
themselves bound to such a programme out of con-
sideration for the large number of readers of the
" Illustr.ated Scientific News " who had become
subscribers to the amalgamated periodical ; but because
they were convinced that in the new significance and
importance which applied science is now recognised as
having in every department of the national life, there
was a real demand for an organ which should deal with
such subjects in a manner that was at once authorita-
tive, comprehensible, and interesting. No pains or
expense were therefore spared to attain this end, and
it is an ideal to which the conductors of the paper will
steadily adhere during the coming year. The difficul-
ties that have presented themselves are none the less
considerable. In the first place there has been the
question of preserving the former scientific interests of
the paper without diminution, while adding the new
subjects. That has been a matter which has involved
considerable additional expense, because it has
necessitated not only the payment for special articles,
but the enlargement of the paper by the double method
of increasing the number of its pages and of adding to
the quantitv of contributed matter by the reduction, on
several pages, of the type. We believe that in spite of
one or two complaints that this or that subject has

been included which an isolated reader did not
want, the endeavour has completely succeeded, and
that we have added alike to the attractiveness and
value of "Knowledge." The feature of attractive-
ness has also involved better printing, a very large
increase in the number and variety of illustrations, and
a better quality of paper. These matters have been
among the additional sources of expense, and in order
that the standard which has been set up may be main-
tained, we desire to make a special appeal to readers of
" Knowledge .^nd the Scientific News " to give us
an increasing support. There is no other scientific
periodical in the United Kingdom which occupies the
same or even a similar position, and in making this
appeal we feel that we are doing so not only on behalf
of the commercial success of our venture, but on behalf
of the popular advancement of scientific teaching and
information.

-Some of the commercial difficulties that we have en-
countered in an anxious year have made it necessary to
effect a re-arrangement of the editorial staff, but during
the coming year the journal will be conducted by the
same editors as heretofore, with the exception that
Mr. E. Walter Maunder, F.R.A.S., in whose hands
the Astronomical editorship of "Knowledge" has
been so long, and whose services to the paper have
been most valuable, will, we regret to say, no longer
be able to continue in that position. We hope, never-
theless, that his name will continue to appear as
a contributor to the paper. Steps are being taken to
place the astronomical editorship in responsible hands,
and articles on astronomical subjects will continue to
appear from Miss Agnes Gierke, Dr. W. J. S. Lockyer,
Mr. J. E. Gore, and Mr. Shackleton.

In addition to soine fine astronomical photographs
which we hope to present as full-page supplements, we
are having prepared some star maps on a new and
original system, which, when collected, should form a
complete atlas of the heavens.

It is proposed to continue the articles on Physics,
Chemistry, and Geology, which have been a feature of
the later numbers, and we have been promised a con-
tinuance of contributions by Prof. A. W. Porter, Dr.
F. Mollwo Perkin, Prof. Grenville Cole, and Mr.
H. J. H. Fenton. Natural History will again be ex-
pounded by such authorities as Dr. Sclater, Mr.
Lydekker, Mr. P. Collins, and others. In all other
respects "Knowledge" will be conducted on those
lines which in the past year we hope have proved to
be acceptable to the great majority of our readers.

KNOWLEDGE & SCIENTIFIC NEWS.

[Feb., 1905.

Modern Cosmogonies.

XII.— Our Own System,

Bv Miss .Agn-es M. Clerke.

Olr sun is clearly middle-aged. It bears none of
the marks associated with juvenility in stars; and its
decrepitude is in the distant future. It is crossing,
probably, a level tract where recuperation so nearly
balances expenditure that radiation can be maintained
for an indefinite time at a high and fairly uniform
standard. Stars of the solar type pursue the even ten-
our of their way with particularly few interruptions
They show little tendency to intrinsic variability. Their
periodicity, when it exists, is due to the presence of a
companion. Light-changes can thus be impressed
upon them by external influence; they do not con-
Kpicuously arise through native instability.

Our planet, accordingly, is attached to a safe and
steady luminary; one subject, not to destructive spasms,
but to vicissitudes so mild as to evade distinct meteoro-
logical recognition. It is, moreover, governed by a
polity settled on a broad basis of tranquillity and per-
manence. All this is as it should be. The conditions
specified were a pre-requisite to the unfolding of human
destinies. Nor can it be confidently asserted that they
have been realised anywhere else. Our system may
be unique; while, on the other hand, replicas
of it might, imperceptibly to us, be profusely
scattered throupV the wide realms of space. It
is certain that a telescopic observer on Sirius or a
Centauri would see our sun unattended; not even Jupi-
ter could be brought into view by optical appliances
in any degree comparable to those at our disposal.
There are, nevertheless, strict limitations to the possi-
ble diffusion of planetary worlds like those that wander
amid the zodiacal constellations. We have become
aware of incapacitating circumstances, by which a
multitude of stars are precluded from maintaining re-
tinues of subordinate globes. Spectroscopic dis-
coveries have compelled a revision of ideas as to cos-
mical arrangements. Especially the large proportion
established by them of binary to single stars makes
it impossible any longer to regard the solar system as
a pattern copied at large throughout the sidereal
domain. We cannot, then, compare it with any other;
the mechanism of which the earth forms part must,
perforce, be studied in itself, and by itself; and it may,
for aught that appears, be the outcome of special and
peculiar design.

The machine in question is self-sustaining and self-
rrgulating; no extraneous influence noticeably affects
its working. This exemption from disturbance is the
fortunate consequence of its i.solafion. A great void
surrounds it. The span of Neptune's orbit is but a
h.md-breaflth rompircd with the trcmendf)us unoccupied
gulf outside— unoccupied, that is to sav, by bodies of
substantial ma.ss. The feebleness of star-light relative-
ly to sun-light affords some kind of measure of the
impotence of stellar attractions to compete with the
over-ruling gravitational power that sways the planet-
ary circulation. This it is which gives to it such re-
markable stability. The incomparable superiority of
the sun over his dependant orbs not only safeguards
them against foreign interference, but reduces to in-
significance their mutual perturbations. Hence, the
strong concentration of force exemplified in our .system

— the absolutely despotic nature of the authority exer-
cised— makes for a settled order by excluding subver-
sive change.

The organisation of the solar kingdom, as disclosed
by modern research, is greatly more varied and com-
plex than Laplace took it to be. His genetic scheme
was, indeed, no sooner promulgated than deviations
from the regularity and unanimity of movement upon
which it was based began to assert their inconvenient
reality. They have since multiplied; and, emerging to
notice under the most unlikely aspects, they occasion
incongruities which tax, for their explanation, all the
resources and audacities of the most inventive cos-
mogonists. Let us briefly consider their nature.

The swarm of asteroids that bridge the gap between
Mars and Jupiter revolve, it is true, with the general
swirl of planetary movement; but use a large licence
as regards the shape and lie of their orbits, and their
partial exemption from the rules of the road becomes
entire for comets and meteors, which have proved them-
selves, nevertheless, to be aboriginal in our system by
their full participation in its proper motion. Finally,
several of the major planets set convention at defiance
in the arrangement of their several households, and
thereby intimate departures from the supposed normal
course of development so frequent and so considerable
as to shake belief even in its qualified prevalence. Thus,
the anomalously short period of I'hobos, the inner
satellite of Mars, besides throwing doubt over its own
mode of origin, tends to obscure the history of its more
sedately circulating associate. The sub-systems of
Uranus and Neptune exhibit, moreover, eddies of re-
trograde movement, suggesting primitive disturbances
of a fundamental kind; while the surprising disclosures
connected with .Saturn's first-born, and furthest satel-
lite, have added one more knotted thread to the tangled
skein we would fain unravel. L'ntil acquaintance was
made with Phcebe, counter-flows of revolution within
the same satellite-family were unknown, and, if con-
templated at all, would have been scouted as impossi-
ble. One ternary star, to be sure — t Scorpii — had been
recognised as probably owning an immediate and a
more remote attendant, in oppositely directed orbital
movement; but the cases are in many ways disparate,
and the analog}-, though instructive, is imperfect.

If the ninth Saturnian moon is to be regarded as
sprung from the mass of its primary, a total change
in the condition of the parent body must have super-
\ened during the long interval between its separation
and that of its successor lapcfus. The change, in
Professor W. H. Pickering's opinion,* was nothing
less than a reversal in the sense of axial rotation. The
nebulous spheroid destined to develop into the wonder-
ful .Saturnian system had a di.'imcter, when Phoebe
was thrown off from it, of sixteen million miles, and
g}Tatcd tranquilly from east to west, in a period of
about a year and a half. The action of sun-raised
tides, however, availed first to destroy, and finally to
invert this movement; for the natural outcome of tidal
friction is synchronism, and this implies agreement,
both in period and direction, betwct-n the rotation and
revolution of the body acted upon. Acceleration
through contraction did the rest; and before lapctus
entered on its separate career, the originating globe
span normally in seventy-nine days. The view that
such was the course of events is plausible at first sight;

'Harvard Annals, Vol. LIII. p. 61, where, however, the
reversal is explained by a shifting of the axis of rotation. Tlie
mode of action described in the text was long ago suggested by
Kirkwood.

Feb., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

yet the doubt remains whether the cause alleged was
adequate to the effect produced. Afthe distance of
Saturn, solar tidal friction exerts only about one-
twenty-thousandth its power on the earth '; its efficacy
would, it is true, be greatly enhanced by the distension
of the mass subjected to it; but approximately to what
extent, it baffles our powers of calculation to determine.

The one certain inference derivable from the diver-
sity of facts ascertained within the last hundred years
is that our world is not (so to speak) machine-made.
The modus operandi employed to disengage the planets
from their nebulous matrix was not of cast-iron
rigidity; it was adaptable to circumstances; it left room
for the display of boundless inventiveness in details.
This, nevertheless, was made to consist with the per-
fect preservation of the main order, both in design
and operation. Tlie general plan is broadly laid down
and unmistakable, and the springs of the machine are
undisturbed in their free play. And for the primary
reason that departures from regularity, which might
in any way, prove a menace to stability, affect bodies
of negligible mass. Tlie great swing of settled move-
ment goes on irrespectively of them. De minimis ncn
curat lex. Thus, the erratic behaviour of comets is
harmless only because of their insignificance. If pur-
sued by substantially attractive masses, it could not
fail to jeopardise the planetary adjustments. Even the
asteroids would be unsafe neighbours but for their
impotence; and it is remarkable that Mercury, by far
the smallest of the major planets, circulates along a
track of the asteroidal type. It would seem as if an
important size carried with it an obligation to revolve
in an orbit of small eccentricity, inclined at a low angle
to the principal plane of the system. The reason why
this should be so is not obvious; but were it otherwise,
the equilibrium, now so firmly established, would sub-
sist precariously, or not at all.

The assertion, indeed, that it is firmly established,
can only be made under reserve. We are ignorant of
any causes tending towards its overthrow; yet they
may supervene, or be already subtly active. One such
lurking possibility is the presence of a resisting medium
in interplanetary space, ^^■aifs and strays of matter
must, at any rate, be encountered there — outlawed
molecules, self-expelled from the gaseous envelopes of
feeble globes; thin remnants of cometary paraphernalia,
driven off amid the fugitive splendours of perihelion;
products of ionic dissociation set flying by the impact
of ultra-violet light — and all disseminated through an
ethereal ocean, which " is cut away before, and closes
from behind," as moving bodies traverse it. That its
indifference is shared by ordinarv material substances,
when in the last stage of attenuation, is a plausible
but unverified conjecture. It is only safe to say that
retardation of velocity in what may pass for empty
space is insensible, or null.

There may, nevertheless, be springs of decadence in
the solar system. Some of them have been discussed
by M. Poincare,f whose confidence in the reassuring
demonstrations of Laplace and Lagrange is inversely
proportional to the magnitude of the terms they were
forced to neglect. They dealt with fictitious globes,
devoid of appreciable dimensions, and swayed by the
strict Newtonian law. But the real planets and their
satellites are acted on by other forces as well, frictional,
magnetic, radio-repulsive; and their joint effects may
not be wholly evanescent. The tidal drag on rotation

• G. H. Darwin, Phil. Trans. Vol. CLXXII., p. 526: Moulton,
Astrooh. Jour., Vol. XI.. p. no.
t Annuaire du Bureau des Longitudes, 1898

undoubtedly occasions a small but irretrievable loss
of energy. The moon, for instance, as M. Poincare
states, now gains, by the reactive consequences of tidal
friction in widening its orbit, no more than .^ the vii
viva of which the earth is deprived by the infinitesimal
slowing down of its rotation. And the remaining "ths,
being dissipated abroad as heat, are finally abstracted
from the system. The ultimate state, we arc told, to-
wards which tlie planetary mechanism tends, is that
of the synchronous revolution, in a period of about
twelve years, of all its members. This might, apart
fiom a possibly resisting medium, have indefinite
permanence; otherwise precipitation to the centre would
gradually ensue, and one solitar}- sphere, cold, stark,
and unilluminated, would replace the radiant orb of
our cerulean skies, with its diversified and exquisitely
poised cortege. Unsecured drafts upon futurity, how-
ever, are not among the most valuable assets of science;
and a consummation so incalculably remote may be
anticipated by a score of unforeseen contingencies.
What can be, and has been ascertained, is the relative
durability of the scheme with which the visible destinies
of the human race are so closely connected. It will,
beyond question, last long enough for their accom-
plishment. Curiosity that would seek to penetrate
further is likely to remain ungratified.

But this is not all. There are other, and incalculable
items in the account. The sun, although an autocrat
within his own dominion, is himself subject to ex-
ternal influences. As a star, he is compelled to follow
whithersoever the combined attractions of his fellow-
stars draw him; nor can we thoroughly interpret the
summons which he obeys. The immediate outcome in
the transport of the solar system towards the constel-
lation Lyra, has, it is true, been determined; but the
eventual scope and purpose of the journey remain pro-
foundly obscure. The pace is to be reckoned as leis-
urely; twelve miles a second is little more than half the
average stellar speed. We should, however, probably
suffer no inconvenience from being whirled through
the ether in the train of such a stellar thunderbolt as
.Arcturus. Only the excessive velocities of any ad-
ventitious bodies we might happen to pick up would
betray to ordinary experience the fact of our own swift
progress. As it is, our sweepings from space appear
to be scanty. If shreds from inchoate worlds, or dust
of crumbled worlds, strewed the path of our system,
they should be annexed by it in its passage, tem-
porarily or completely; and we should then expect to
find the apex of the sun's way marked, if no otherwise,
by the predominant inflow from that quarter of comets
and meteors. Yet there is no trace of such a prefer-
ence in the distribution of their orbits. Hence the en-
forced conclusion that the sun has attached to him,
besides the members of his immediate household, an
indefinite crowd of distant retainers, which, by their
attendance upon his march, claim with him original
corporate unity. To this rule there may be a few
exceptions. An occasional aerolite probably enters the
earth's atmosphere with hyperbolic velocity, and takes
rank accordingly as, in the strictest -sense, a foreign
intruder; but the broad truth can scarcely be challenged
that the sun travels through a virtual void.

We can, however, face no necessity why he should
for ever continue to do so. Widely different conditions
seem to prevail near the centre, and out towards the
circumference of the sidereal world. What may be
designated the interior vacuity of the Milky Way is
occupied mainly by stars of the solar type, including

KNOWLEDGE & SCIENTIFIC NEWS.

[Feb., 1905.

one to our apprehension super-eminent over the rest;
they are separated by vast, apparently clear intervals;
they are non-nebulous, and of stable constitution. This
secure habitat is ours for the present; it may, neverthe-
less, at some future time be exchanged for one less
exempt from disturbance. The shape and size of the
sun's orbit are utterly unknown ; the changes of en-
vironment, accordingly, that will accompany the
description of it defy conjecture. Our actual course is
inclined at a small angle to the plane of the Milkv Way.
It will presumably become deflected; but perhaps not
sufficiently to keep our system clear of entanglement
with the galactic star-throngs. In our ignorance of
their composition, no forecast of the results can be at-
tempted; they are uncertain and exorbitantly remote.
Moreover, the comparative slowness of the sun's motion
in a manner guarantees the permanence of his sub-
sisting cosmical relations. For anything that science
can tell, they may ultimately be subverted by some pre-
ordained catastrophe; but the possibility lies outside the
field of legitimate speculation.

The universe, as reflected in the mind of man, gains
extent as the mirror acquires polish. Early astrono-
mers conceived of but one solar system, and one "daedal
earth," upon which the " pale populace of heaven "
rained influences sinister or propitious. Later, human
egotism took another form. The whole universe was
assimilated to our particular little settlement in it.
Terrestrial conditions were universalised. None diver-
gent from them were counted admissible or profitable.
But one answer seemed possible to the perpetual Cui
bono? with which restless thought assailed the heavens.
But one purpose was regarded as worthy of fulfilment;
that of multiplying, in distant sidereal climes, copies
of our own planet, and of providing suitable locations
for myriads of intellectual beings, as little alien to our-
selves as might be compatible with the minimum of
diversity in their material surroundings.

The spread of this astral philanthropy has, neverthe-
less, been in some measure checked by the advance of
knowledge. Our position and circumstances have been
shown by it to be, if not quite peculiar, at any rate very
far from inevitable. It has reduced by a process of ex-
clusions to a relatively limited number the class of
stars that can fairly be regarded as possible centres of
vitality; it has immensely widened the scope of dis-
cernible variety in cosmical arrangements, and held out
warnings against errors of interpretation due to con-
genital prepossessions. And we shall surely not
wander from the truth by recognising our inability to
penetrate all the depths and intricacies of Infinite De-
sign.

To Prevent the Stripping of
Photographic Films.

I\ warm climates it is often most difTirult to prevent the
gelatine film from becoming detached from a plate
during development, and the usual methods, such as
adding a little alcohol to the developer are not sufficient.
Other methods are objectionable on account of their
effect on the development or fixing. M. Mercier has
lately tried, with good effects, tannin the gelatine. A
bath is made up of the following :— Alcohol (90°)
250 cc, tannin 60 gr., water 500 cc. The plates are
immersed for two or three minutes in this bath, after
which they are carefully washed before being placed in
the developer. The final washing must be continued
until all traces of tannin have disappeared.

Progress ^vith Airships
in 1904.

By Major B. Baden-Powell.

XoTWiTiiSTANDiNC. thc \cry tempting bait of a prize of
;^"2o,ooo for an airship capable of attaining certain
speeds over a fixed course, the competition in connec-
tion with the World's Fair at St. Louis can hardly be
characterized as a success. Not only was there a lack
of machines specially built with the object of carrying
off this prize, but there was even a noticeable absence
of those in existence which might have been able to
comply with the conditions. M. Santos Duinont, for
some reason not yet clearly explained, withdrew after
taking his powerful new airship across the Atlantic.
MM. Lebaudy do not seem to have had any intention
of submitting for trial their most successful machine,
nor did M. Deutsch send over more than a model of his
" Ville de Paris." But what is even more unaccount-
able is that American inventors, such as the Messrs.
Wright and Prof. Langley, were conspicuous by their
absence, and did not enter their flying machines even
for show. The rumours we have heard of Mr. J. P.
Holland, of submarine-boat fame, and Prof. Graham
Bell, the inventor of thc telephone, having respectively
devised new apparatus to navigate the air, have re-
ceived no corroboration from St. Louis.

However, it cannot be said that there were no air-
ships at thc Fair. Three of them were open to inspec-
tion in the huge sheds specially constructed for housing
the competing vessels. Two of them actually made
ascents, and with some success. Unfortunately, the
most promising of the three, that of M. Francois, could
not even be inflated with gas. This apparatus consists
of an elongated bailf)on ol 1,150 cubic metres, support-
ing a wooden car containing a 25-28 h.p. Lambert
water-cooled petrol engine (weighing 270 Uis.), which
rotates two pairs of screw propellers. There are two
horizontal shafts, one on each side of the car. Each of
these has a propeller mounted on each end of it. The
fore screws (about 9 ft. diameter) are smaller than
those in rear (12 ft.), the idea being that the larger
after screw will be alile to effect a bigger column of air
without, presumably, ha\ing so much work to do as if
the smaller screw had not already acted on an inner
column of air. The reasoning of this may not seem to
be quite sound, but practical trials alone could prove if
there was anything in it, and we can but watch for
results.

Mr. Baldwin, whose name was much before the
English public some 15 years ago on account of his
bold and sensational parachute descents, exhibited an
apparatus of the Santos Dumont type. As may be
seen from the photograph, the elongated balloon sup-
ported a long trussed-girder beam, towards the fore-
end of which was a two-cylinder petrol engine of 5 h.p.
(almost hidden, in the photograph, by the figure of Mr.
Baldwin). A tractor screw was placed at the fore-end.
This was 10 ft. in diameter, the blades being each
3 ft. 4 ins. long by 2 ft. 2 ins. wide. A large rudder
was placed behind, moved by tiller lines. This machine
made its first ascent on October 25, piloted bv Mr.
Knabenschue. There was a light wind blowing, about
six to eight miles per hour, but this proved altogether
too strong for the airship, which made several turns
around, but failed to stem the breeze, and was carried
away over the town of .St. Louis. Some days after-

Feb., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

Benbow's Airship.

KNOWLEDGE & SCIENTIFIC NEWS.

[Feb., 1905.

The Lebaudy, 1904.

wards, however, during a calm, a more successful
voyage was made, and the vessel, after taking a tour
above the Fair grounds, returned successfully to its
point of departure.

The third machine was that of Mr. Benbow. This
was a beautifully-shaped balloon of 73 ft. long by
20 ft. greatest diameter, with pointed ends, beneath
which was suspended a car-frame of angle-steel carry-
ing a pair of feathering paddle-wheel propellers. A
4-cylinder engine developing 10 h.p. rotated these
wheels, which were so constructed that normally the
blades were opened while passing the lower portion of
their path and closed while going over the upper half
"f the circle. But by an ingenious arrangement of
' .ims this action could be altered, so that instead of
driving forward, it was possible to cause the propellers
to give an upward thrust, or even to reverse and give a
downward or backward thrust. This arrangement may
be good in theory, but it was palpable that much power
was lost in the gearing and complication necessary.
This apparatus was tried on several days in almost dead
calms, but owing to insufficiency of lift it ascended to
no great height. It was, however, well able to exhibit
its powers, and the exact rate of progress could be
nieasured. The fans revolved at exactly one revolu-
tion per second, and the airship progressed at a rate of
just about three miles an hf)ur, this being, of course,
altogether insufficient for a praclirable airship.

But while these more or less abortive attempts to
further progress with airships were being carried on in
.America, some really impf)rtant work was developing

on this side of the .\tlantic. P'rancc, the birthplace of
the balloon and the country in which nearly all the
more notable advances in aerial navigation have taken
place, now contains what may uiidoulstedly be called
the first really practicable airship.

It will be remembered how, in November, 1903, the
Lebaudy airship, which had had so wonderfully success-
ful a career, came to grief, \\lTilc l.'inding at Mciidon.

The Lebaudy from Underneath.

(This apparatus was fully described in the Illustrated
Scientific News of September, 1903.) The vessel was
completely wrecked, but M. Julliot, backed by the
affluence of MM. Paul and Pierre Lebaudy, at once
started on the construction of a new machine. 'Hiis
has now been completed, and has undergone,- its trials
with much success. The new machine is practically
of the same design as the old one; indeed, most parts of
it are the same, repaired. The gas-vessel is new.

1905]

KNOWLEDGE & SCIENTIFIC NEWS.

havintf a somewhat different shaped stern and contain-
ing- a rather larger volume of gas, namely, 2,600
cubic metres (94,000 c. feet). It is 58 metres long over
all; the greatest diameter, g m. 80, being 24 m. 90 from
the bow. The length is therefore about 5.6 times the
maximum diameter. The surface of the balloon is
about 1,300 square metres, and the weight of the
envelope is 550 kilos. The material consists of four
layers, one of cotton-cloth with a layer of caoutchouc,
one-tenth of a millimetre thick, then another of cloth,
and finally one of caoutchouc on the inside.

Tlie former balloon had only two layers of cloth with
caoutchouc between, but it is hoped that this extra
layer will preserve the cotton from impurities in the
gas. The balloon is also varnished with seven coats of
a solution of caoutchouc in benzine, vulcanised with
sulphur, and is painted yellow outside, so as to prevent
the actinic light affecting the caoutchouc. So gas-tight
is this material that 48 hours after its inflation there
was no appreciable loss of gas.

The ballonnet, which can be filled with air as
desired so as to keep the balloon taut, is of 500 c.
metres. The ventilating-fan for this purpose is driven
by the motor, but, when the latter is not working, may
be driven by a small dynamo and accumulator.

In addition to the " manceuvring-valve " at the top
ot the balloon, there are some safety valves automatic-
ally opening under a pressure of 35 millimetres.

The lower portion of the balloon is flat, and is rigidly
stretched on a horizontal oval framwork of steel-
tubing; below this is a long vertical " keel " of steel
tubing, covered with canvas, and at the after end of
this is pivoted the rudder.

This horizontal plane and vertical keel impart great
stability to the vessel while running.

One of the most notable features of the 1904 model
is a large horizontal double-rudder or fin, placed at the
stern of the balloon. This to modify or prevent any
tendency to pitch. There are also two small horizon-
tal rudders at the rear of the keel-frame, just in front
of the vertical rudder.

The car, as before, is suspended from the oval steel
fiame by wire ropes, the thurst of the propellers
being conveyed to the main vessel by a system of rigid
steel tubes leading from the front of the car to the
front of the oval frame.

The propelling mechanism is the same as in last
year's machine. A 4-cyIinder Daimler motor of 40
horsepower, running at speeds from 250 to 1,200 revo-
lutions per minute, rotates the two screw propellers,
one on each side of the car. These screws are 2 metres
44 in diameter and rotate 800 to 1,000 times a minute.

The first voyage of the new airship took place on
the 4th of August. This, however, only lasted some
twelve minutes, being but a trial trip to test the engines
and steering arrangements. Everything proved highly
satisfactory, and a few days later a second journey was
undertaken. The wind on this occasion was blowing
13 miles an hour, yet the vessel rose and manoeuvred
around for a quarter of an hour at a height of 60 to 80
metres above the ground.

Several other short trips were successfully made on
succeeding days, and on the i6th of August a longer
journey was undertaken. This lasted "41 minutes,
during which time the balloon covered a distance of
about 26 kilometres (16 miles). On the 28th of August
another ascent was made, and after 20 minutes of cir-
cling above the grounds, the airship descended and the

aeronauts got out. Just then a strong gust of wind
caught the balloon, the tethering ropes both snapped,
and the balloon rose and floated away without any oc-
cupant ! Instead of rising, as might have been ex-
pected, to a considerable height and being carried off
to a great distance, the i)alloon seems to have kept
low and to have several times actually touched the
earth. Eventually it got caught up in a wood, 70
kilometres from its point of departure, and was deflated
and taken back to its shed, having suffered but little
damage.

.\ number of other voyages were made later on, in-
cluding one on the 22nd of November, which lasted for
I hour and 33 minutes.

On the 22nd of December, tiie last voyage of the year
was made, this being the thirtieth during 1904, and the
sixty-third trial of this tjpe of airship. All these trips
were conducted by M. Juchmes, the aeronaut, who was
usually accompanied by a mechanician and an assistant,
and on several occasions a passenger was also carried.

To have accomplished all these journevs in varying
weather, and, with one exception, each time to have
safely returned to its shed, seems to prove that in this
airship we really have at last a machine capable of
navigating the air, and the promoters would appear
quite justified in alluding to it, as they do, as the
' aerial cruiser."

TKe Herschel Memorial

Mr. J. P. Maclear writes from Beaconscroft. Chiddingfold,
Godalming : "I was doubtful about the inscription I sent you
for the north side of the Herschel Obelisk at Claremont,
Cape of Good Hope. I now send an exact copy."

KP- iUfS-fili^tAl!--

-iCULUM SESQUIPEDALE
!N ANCLIA

^^-^ ^ ~^cfUM MANIBUS
y PDSUIT,,,...

mVcant

lTLESTES
CIES"
IT.
Nt

;IP50

ETQUATU,
QUOAD LQNC1L_..
CRSES NEBUL£Q&

PElxiTlssl^lE mrx\

Sic OPUS IlLUD iKSl

APATRE CLARQ ETA?

BGitEALi SOB CCE-C =RCt

E02EM CcAS; CCol

Bronze Tablet (about 11x15 inches) of a Latin Inscription for the
Herschel Obelisk at Feldhausen, Cape of Good Hope.

W. J. Herschel, Scripsit, May-July, 1904. Photo, hy A. S. Rencliil, Sell'., 1904.

KNOWLEDGE & SCIENTIFIC NEWS.

[Feb., 1905.

Photography.

Pure and Applied.

By Chapman Jones, F.l.C, F.C.S., &c.

Dr. Russell's Experiiiie>its. — Ln^t month I referred to
the production of the developable condition by emana-
tions from various substances as in Dr. Russell's ex-
periments, and showed that although some results
appear to indicate that the effect is due to a gas, and
that this gas is the vapour of hydrogen peroxide, others
are generally allowed to be difficult to account for on
this simple hypothesis.

Professor j. Joly, in a letter to Xature last August,
asks with regard to Dr. Russell's experiments and his
suggestion that peroxide of hydrogen is the active
agent, " ought we not rather to seek the explanation in
the ionising properties of metals indicated by other
observations?" He founds this question on his ob-
servation that pure mercury and polished speculum
metal in contact with a rapid plate under absolute
alcohol in an airtight desiccator over calcium chloride
produced the developable condition in a gelatino-
bromide plate just as vigorously as if it were obtained
in ordinary moist air. It is, perhaps, worth while to
sum up the recorded experiences of Dr. Russell with
regard to conditions similar to those described by
Professor Joly.

.\s to mercury. Dr. Russell found that, if pure, it was
inactive, and that an active sample might be made in-
active by purification, and that if pure and inactive the
addition to it of one-thirty-thousandth of its weight of
zinc rendered it very active.

As to moisture. Dr. Russell at first found no differ-
ence whether the action took place in air saturated with
moisture or air dried with sulphuric acid or calcium
chloride, or in an atmosphere of hydrogen. Later on,
when he had found how intimately hydrogen peroxide
was connected with the results obtained, he remarks
that a gelatine plate is never really dry. He seems to
have repeated the experiment of trying the different
effects of an atmosphere dried by calcium chloride and
an atmosphere kept moist, and found that after three
days " the damp plate had much the darker picture on
it." By passing dry air over zinc nothing was given
off that affected a plate, but when moist air was passed
over the metal and then allowed to impinge on the
plate, the change was effected. He found also that
dry alcohol neither transmitted the action nor was
made active by putting zinc in it, but by adding the
merest trace of w-ater to the alcohol, the zinc did make
it active.

Messrs. Blaas and Czermak (Science Abstracts,
Section A, No. 2559, 1904) record the old and well-
known fact that many substances after exposure to
light are able to affect a photographic plate, or affect it
more readily than they did before insolation. They
say that this property is connected with the occlusion
of ozone and that bright or amalgamated zinc possesses
the property, and that many substances emit a diffuse
radiation which is reflected at mirror-like surfaces.
Dr. Russell states that he found ozone to be without
effect, and in a communication to the Royal Society last
June dealt with the effect of exposure to sunlight in
rendering " active " substances more active. He says
that " bodies other than those which may contain resin
or allif^d '^nh<;tnnres are not affcrtrrl in fhi<; w.nv by

light." " Metals are not rendered active by sunlight."
Dr. Luppo-Cramer finds that while a gelatino-
bromide plate is affected by hydrogen peroxide, a coUo-
dio-bromide plate is not, and hence considers that the
gelatine has a vital influence on the result. Hut his
experiments are not strictly comparable with Dr.
Russell's, as he immersed his plates in weak .solutions
of the peroxide, though he considers that this is the
same in effect as exposing them to its vapour. I be-
lieve it has been observed that films apart from the
glass support are not affected by these emanations.
Thus it would appear that the glass, which is not
permeable by them, is necessary to prevent them pass-
ing through the gelatine film and escaping with the
production of little or no effect on the sensitive .salt.

There arc many other observations that bear upon
this subject in a more or less direct manner, but I
think that I have set down sufiicient to show that there
remains a considerable measure of uncertainty with re-
gard to some of the observations, and that it is im-
possible to rest satisfied with the suggestion that the
effects are the simple results of the action of (leroxide
of hydrogen. The peroxide doubtless has something
to do with it, and, perhaps, is itself one of the effects
of the action rather than the cause. We do not yet
know how silver bromide is changed when it assumes
the developable condition, though the evidence is very
strongly in favour of a merely physical alteration.
Such an alteration seems more likely to result from the
impact of some form of radiant energy, than to be the
direct result of mere contact with such a suljstancc as
peroxide of hydrogen.

T/ic Use of the Optical Zaw/ir;/. — Projection lanterns
are often used in such a manner that one might
well suppose that they are regarded simply as
" magic " lanterns, and that so long as an enlarged
image of the slide is produced on the screen, and that
the image is tolerably well defined and sufficiently
bright, every desirable condition has been fulfilled.
.Some, though not many, go so far as to consider the
convenience of the audience and endeavour to arrange
so that the middle of the screen is, al the highest, about
level with their eyes. .Still fewer pay attention to what
should be one of the simplest and most primary of
rules, namely that the image on the sheet ought never
to be seen to move or vary in any way in the matter of
adjustment. But there is very much more than this in
the correct use of a lantern. There is a proper point
from which every flat representation of a solid object or
\iew should be looked at, and the skilful or scientific
exhibition of a picture renders it at least possible for the
observer to see it from this point or from a position at
a similar or greater distance. If a three-inch slide is
printed by contact from a negative taken with a six-
inch lens, the viewing point is always equal to twice
the length that the full three inches would be repre-
sented by r)n the sheet. If a twelve-foot sheet would
be covered by the three-inch slide, the nearest specta-
tor should be twenty-four feet from the sheet, t'nder
these conditions the view as shown will subtend the
same angle (or a less angle, allowing for the spectators
who are behind the front row-) as the original view did
from the position at which it was photographed. But
suppose the hrdi is not large enough to allow- of such a
distance, some may object. If the distance between
the front row and the sheet cannot be more than twelve
feet, then bring the lantern nearer and give a six-foot
picture, and the conditions are fulfilled. Of course,
size counts for something, but mere size, mere
exaggeration is contemptible.

Feb., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

The

Late Rev. J. M. Bacon.

We arc able to present an excellent likeness of the late
Rev. John Mackenzie Bacon, F.R.A.S., whose sudden
death at Christmas was so widely deplored. Born in
1846, and educated at Trinity College, Cambridge, he
was ordained in 1870, and for some years was curate
at Harston, Cambridgeshire. Latterly he had not
taken regular duty, but had devoted himself to scientific
pursuits. At his home at Coldash, near Newbury, he
had a small observatory, and he took part in three
expeditions to observe eclipses of the sun. He had

THE LATE REV. J. M. BACON.

also conducted numerous interesting experiments in
acoustics and in meteorology. But his name was most
widely known as an intrepid balloonist, he having for
many years made frequent ascents in the cause of
science, often accompanied bv his daughter. Miss
Gertrude Bacon. He published two books on the sub-
ject— " By Land and Sky " in 1900, and " The
Dominion of the Air " in 1902.

Mr. Bacon has contributed many interesting articles
to " K^■o\^■ LEDGE," and we now have one in hand on
" Seeing beneath the Waves," which we hope to pub-
lish very shortly.

Heredity.

The continuation of Mr. J. C. Shenstone's article has
unfortunately been crowded out this month, but will
appear in our next issue.

SIR. WILLIAM TUR.NER on

TKe CraLi\iology of the
People of Scotland.

By Dr. J. G. McPhersun, F.R.S.i;.

The learned Professor of Anatomy in the University of
Edinburgh has just received the Keith Prize from the
Royal Society of Edinburgh for his " Contribution to
the Craniology of the People of Scotland."

For several years he has been forming a collection
of Scottish skulls with a view of studying the charac-
ters of these skulls. He has had considerable ditTiculty
in acquiring a suitable number from which to deter-
mine the type skull of the Scottish people. A great
number of the skulls available to a professor are of
necessity from the bodies of the pauper part of the
community; and these can give no proper conception
of the cranial type of the well-educated and well-to-do
classes.

Through the kind interest and help of his many
former pupils and friends. Professor Sir William
Turner has obtained skulls from definite districts all
over Scotland. But Edinburgh, Haddington, Fife,
and Mid-Lothian have furnished him with a consider-
able proportion of the number. He has, in this way,
been able to study one hundred and seventy-six skulls
outwith the ordinary stock of anatomical specimens;
and these represent the characters of the skulls of the
people of Central Scotland.

After a very careful and minute examination ol these
specimens, the Professor drew some definite conclu-
sions as to the form, dimensions, and proportions
which prevailed in the crania generally. The shape of
the cranium, from its influence on the form of the head
and from its connection with the brain which it once
enclosed, has for long attracted the attention of
anatomists. The relations of the length to the breadth
and the grouping of skulls into the " elongated " and
the "rounded" have been of much importance in de-
termining the distinctions of the human races. But the
Professor has combined observations on the shape of a
skull with exact measurements.

The measurements are taken with callipers in
straight lines between certain definite points, in order
to ascertain the length, breadth, and height of the
exterior of the cranial box; with a graduated tapeline
over the curved walls of the outer table, the arcs and
circumference are determined ; and with small shot
the internal capacity is known.

Speaking generally. Professor Turner has concluded
that the Scottish skull is large and capacious. Its
vertex has a low, rounded arch in the vertical trans-
verse plane. Its side walls are not vertical, but they
bulge slightly outwards, so that the greatest breadth
is at or near the squamous suture.

In the men the longest skull was eight inches, and
the shortest 6.V inches, the mean being 7.35 inches.
In the women the longest skull was slightly over 7!
inches; the shortest was 6.34 inches— the mean being
seven inches. The length of the Scottish skull
indicated a brain longer than existed in the long-headed
black races.

Professor Turner found that m the men the broadest
skull was b\ inches, and the narrowest 5.12 inches—
the mean being 5. 86 inches. In the women the
broadest skull was six inches, and the narrowest five
inches— the mean being 5.43 inches.

KNOWLEDGE & SCIENTIFIC NEWS.

[Feb., 1905.

Thus the average male skull is longer than that of
the female bv .3^ inch, and broader by .43 inch.

The cephalic index expresses the relation which the
greatest breadth of a skull bears to its greatest length.
In these skulls examined by Professor Turner, the
index ranged from .87 to .68; the mean in the men and
in the women being about the same, .77; that is, in the
short-headed class. From this it is clear that a strong
short-headed strain pervades the population of Scot-
land at the present time. The Scottish people may be
long-headed in calculation and logical acumen, as is
often mentioned as a social characteristic; yet
anatomicallv this is not the case.

The vertical index expresses the relation which the
height bears to the maximum length. This index
ranged from .64 to .79. The mean in the men was
slightly more than in the women, approximating .71.

The relations of the length to the breadth and to the
height of a cranium have long been recognised as im-
portant subjects of investigation in the study of racial
characters of skulls; but the relations of the breadth
and height to each other have not had an equal atten-
tion given to them. Jn well-pronounced long-he.-ided
races like the Esquimaux and .Australians, the height
is greater than the breadth, forming a high, narrow
skull. In the short-headed races, like the Chinese,
the breadth is greater than the height, indicating a
wide, low skull. A striking feature of the Scottish
crania is the preponderance of the cephalic index over
the vertical index; accordingly they are of the type
" wide low " skull.

Professor Turner's measurement of the horizontal
circumference of the Scottish skulls brought out these
facts : — In the male, the maximum is 22* inches;
minimum, 19J inches; mean, 21.9 inches. In ;the
female, maximum, 21.65 inches; minimum, i8i inches;
mean, 20 inches; so that the average horizontal circum-
ference of a man's skull is greater than that of a wornan
by about two inches. His measurement of the vertical
across circumference brought out these facts : — In the
male the maximum is 18J inches, the minimum 15 J
inches, and the mean 17 inches; in the female, the
maximum 18 inches, the minimum 15 inches, and the
mean 16 inches; so that the average vertical transverse
circumference of a man's skull exceeds that of the
female by an inch.

One of the most important series of measurements
was of the total longitudinal arc of the skull (including
the frontal, parietal, and occipital arcs). The
maximum male skull was 22 inches, the minimum
18.4 inches, giving a mean of 20^ inches; the maximum
female skull was 21. i inches, the minimum 17.3 inches,
giving a mean of 19J inches; so that the average longi-
tudinal circumference of the male skull exceeds that of
the female by an inch.

The Professor took the internal capacity of the skull
with small shot. .And he found among the 115 craniii
examined (73 males and 42 females), that the maximum
capacity in the male skulls was 118J cubic inches, the
minimum 78';, and the mean 94^; in the female, maxi-
mum 104, minimum 70, and average 84J cubic inches.
This shows that the female skull is about 10 per cent,
less capacious than the male. This agrees with the
approximates of the skull capacities of other races and
peoples. In a series of comparisons he found that the
capacity of the Scottish male skull is somewhat in
excess of that ascribed to the crania of European men.
He does not, however, conclude from this that the
.Scottish men have a superior intellectual endowment.
.Many other factors than the volume of the cranial

cavity have to be taken into consideration in the
estimation of intellectual power.

In the study of the face it is important to dL-terniine
the degree of forward projection of the upper jaw.
Sir William Turner found that the Scottish skulls are
characterised by an almost complete absence of
prognathism (projecting jaw). The relation between
the height of the nose and the greatest width of that
aperture contributes one of the most important
anthropological characters of the face. In the males
he found the mean height was 2.10 inches, and in the
females, 1.96 inches. The width in the males averaged
.91 inch, in the females .87 inch. The height, there-
fore, is more than twice the width; and the occurrence
of wide nostrils in the Scottish face may be regarded
as accidental, and due, perhaps, to intermixture
through an ancestor with that peculiarity. The
customary form of nose in Scotland is long, relatively
narrow, with a well-marked bridge, and projecting so
that the nose distinctly projects beyond a line drawn
between the front part of the two cheek bones.

.Another important character is the relation between
the length and breadth of the face. Professor Turner
found the mean length in the males to be 4.72 inches,
and in the females, 4.28 inches; he also found the
mean breadths to be 5.20 and 4.78 respectively. The
breadth of the face is about half an inch greater than
its length.

The entire jaw had, in most of the specimens, a
massive appearance, which had materially contributed
to give character to the face, and from the marked
vertical diameter of the body of the bone, had con-
stituted an important factor in giving to the entire
face a length which placed it distinctly in the group
where the face is high in relation to the width. The
lower jaw had a well-defined angle, and the body of
the bone was massive on the males, and with a pro-
nounced chin.

Photograph of Electric
SpdLrk.

Perhaps it is not exactly correct to describe this as a
photograph, since light plays no part in its production.
It may more properly be called an " electrograph. "
The manner in which such representations of electric
discharges are produced is as follows : — .An ordinary
photographic plate, enclosed in two light-proof paper
bags (as used in X-ray work), is placed film upwards
on a metal plate, which is insulated. The pointed dis-
chargers of an induction coil, in this case one giving a
lo-inch spark, are placed a few inches apart, touching
the paper envelope. The circuit is then closed, and a
single discharge brought about by holding the hammer
of the coil and letting it go suddenly. The spark in
its passage through the sensitive film decomposes it.
The negative is then developed in the ordinary way.
Variations of many kinds may be made by dispensing
with the metal plate, or by placing the wires one above
and one directly below the negative, or by using knobs
on the dischargers instead of points.

One of the most interesting points to note is the
difference between the positive and negative discharges,
the former being " tree-shaped," while the latter is
feathery or " fan-shaped." With a single spark both
structures are often shown, owing to the oscillatory
nature of the disch;irge. The photograph here repro-
duced was taken by Mr. Hudson, of Harringay.

0
cd

H
U

u
J
u

(/3

Feb., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

Svin

Our
QLiid "Weather."

By William J. S. Lockyer, M.A., Ph.D.

(continued.)

In confining this study, therefore, to pressure, the first
step is to see whether the pressure does change from year
to year, and then, if it does, to see if the curves which
indicate this change are similar to those which represent the
variation in the number of the solar prominences. Taking
the Indian region, for reasons previously given, the reader
will notice that the Bombay curve in fig. 7 does exhibit
short period waves which agree for many years with those
on the solar prominence curve ; it is important to note,
however, that the main eleven-year variation of the
prominences is not so conspicuous as the
shorter-period changes. The apparent se-
condary nature of the former and the pro-
nounced character of the latter is a con-
spicuous feature of pressure curves nearly
all over the world. It will be gathered,
therefore, that greater attention must be given
to this short-period barometric change.

Since the rise in the prominence curve
denotes greater solar activity, and this is
coincident with an excess of atmospheric
pressure over the Indian area, and since this
latter means that a greater amount of air than
usual is piled over India, some part of the
world should be experiencing the reverse
conditions ; in other words, there should be a
large area on which a deficiency of atmos-
pheric pressure exists simultaneously. Now
this is exactly what happens, only one has to
go to the other side of the world to find the
locality. In such a region, then, the curve
representing the pressure variation should be
the reverse of that of India, that is, when
there is excess pressure in one year in India
there should be in the same year a deficiency
in the other. If the reader will glance at the
accompanying diagram (fig. 7) he will see the
curve of the pressure variation at the observatory
at Cordoba in South America, a locality in nearly the
antipodal part of the world to India. This curve is
nearly the exact opposite in every detail, and if one
be reversed and compared with the other their similarity
can be more easily observed.

1870 0 18800 1890 0 1900 C

PR0MINENCES5O-

The fact that when theic ;„ ..;. l....^.,, amount of air
over the Indian area in some years, and a corresponding
deficiency over the Cordoba region during the same
years, or a deficiency over India when there is an excess
over Cordoba, makes one immediately intiuire, What
occurs at other places on the earth's surface ? Such an
investigation has led to some most interesting conclu-
sions. Australia, for instance, Hke Arabia, Ceylon, East
Indies, Straits Settlements, East Africa, Mauritius, Sic,
behaves like India. On the other hand. South America,
the southern parts of the United States, and Honolulu,
resemble the Cordoba type of pressure variation. Thus
we have the world divided into two portions which
behave in opposite ways as regards these barometric
changes. As was to be expected, those regions neigh-
bouring the limits of these two large areas are somewhat
indeterminate, and sometimes favour the one and some-
times the other. The accompanying map (fig. 8) will

Fig. 8.-Ma|
India ( +
other,
portions.

.—Curves to illustrate the wavy nature of the eleven. year
prominence change and its relation to the atmospheric pressure
variations that simultaneously occur in India and S. America.

I illustrating the positions of the two large pressure area types, namely
and +'?) and S. America l— and — V), which behave inversely to each
The ntutrat tine approximately divides the earth into two equal

convey at a glance this pressure distribution, the Indian
and Cordoba regions being indicated by a(-f)and(— )
respectively ; the indeterminate areas are shown by
a (+ ?). The latter can be easily seen by following the
track of the neutral line which approximately divides the
eastern and western hemispheres.

The detection of this pressure variation may turn out
to be an important clue to the close connection between
the meteorological behaviour of regions which are widely
separated. Thus to mention one of many incidences, Sir
John Eliot has recently pointed out that the drought in
the Indian region during the years 1895-1902 was a
more or less general meteorological feature of the
whole area, including Abyssinia, East and South Africa,
Persia, Baluchistan, Afghanistan, probably Tibet, and the
greater part or whole of Australia. Since these areas all
lie within the Indian type of pressure variation above de-
scribed, their meteorological connection seems undoubted.

Many people are more familiar with rainfall variations
than they are with those of pressure, so that the impor-
tance of the latter can best be shown by indicating how-
rainfall is affected by pressure. As a general rule low-
pressure means increase of rain, but this is not always
the case. The main point to be considered in this con-
nection is the nature of region, that is, whether it is land
or water over which the air current has passed, before it
reaches the area in question. Thus what may be a rain-

KNOWLEDGE & SCIENTIFIC NEWS.

[Feb., 1905.

bearing current for one part of a continent may under
similar low pressure conditions be a dry one for other
parts and vice versa. The lie of the land in relation to
the water surface must, therefore, in every case be taken
into account, and it is for this reason that the direction
of the prevailing winds becomes one of extreme impor-
tance.

In the first place, let the pressure and rainfall of
the west coast of India and Ceylon be compared,
but in both of these cases the rainfall of the south-west
monsoon period will be dealt with alone. India, as is
well known, receives its greatest quantity from the
strong moist air current which strikes the country from
its south-west quarter. The strength or weakness of
this current means prosperity or poverty to the country.
A failure of these rains foretells for many districts a ter-
rible drought and consequently loss of crops, a famine,
and a great expenditure of money. Since the west
coast of India is most exposed to the south-west monsoon
wind, and is not shielded by mountains except on its
eastern side, this region should respond in its rainfall to
the pressure variations. In the Ceylon rainfall curve
only those months ha\ e been included during which the
south-west monsoon wind is blowing.

In order that the reader may more easily compare
curves of pressure with those of rainfall, the former have
been inverted. The highest points of the pressure curves
therefore mean lowest pressures, and these correspond
with the peaks of the rainfall curves which denote years of
greatest rain. A glance now at the accompanying dia-
grams (Fig. 9) will illustrate the close resemblance
between these two meteorological elements. In both the
rainfall curves similar kinds of variations seem to exist,
but the rainfall of Ceylon appears to anticipate to a small
extent that of the western coast of India. Thus years
of low pressure for these regions mean, on the average,
years ot good monsoon rains.

Now, not only does this connection hold for this
portion of India, but the same happens in the case
of some parts of Australia. Years of deficient
pressure there mean years of excess rainfall. Since

Ig7(j0 l<!80 0 l89Ud IbuOo

■ I I .... I

PHESS'jaE"'
BOMB.^Y '

but the millions of sheep that have died through want of
water in the last few years indicate the importance of the
value of rain.

In our own isles a similar relation of pressure and
rainfall holds good. Low pressure on the a\ erage means
a greater number of cyclones, while high pressure means
anti-cyclonic conditions on the average. The rainfall of
Great Britain on the whole is chiefly dependent on the

PRE&iURt
BOMBAY.

— Curvea lo show the relation between years o( low pressure
over the India area and the rainfall on the westcoa.tt ol India and
Ceylon dur n« the £outh-We.M Monsoon period.

the pressure variations are nearly similar to those
in India, good rains should occur in the same years.
The annexed diagram (Fig. 10) shows the state of
affairs at Adelaide, Perth, and Albany, the pressure
curves of all these places being very similar. Excess
low pressure corresponds to excess rainfall. What lack
of rain means to this colony only those who have ex-
perienced a droughty season there can vividly testify;

PRESSURE ""^l

ADELAIDE

,0-

L^ .^.t,rj

RAINFALL

■M-

PERTH

i»

RAINFALL

'"1

ALBANY

36-

I670O 1880 0 1830 1900 O

es to show the close relation between the pressure
in India and Australia, and (he rainfall in tlie latter

winds which reach this country from the Atlantic, that
is south-west winds, or, in other words, on cyclones which
pass over the country in a direction north-eastwards.
Since cyclones denote low-pressure areas, the rainfall is
directly dependent on pressure. A perusal of the accom-
panying diagram (Fig. ii) shows how intimate this
relationship between rainfall and pressure is, for the
curves (the pressure curve is here inverted) are so very
closely similar.

Unfortunately, the British Isles, which display pressure
variations intermediate between India and Cordoba, are a
sort of half-way house, and have therefore rather a mixed
type of pressure variation ; there is thus some difticulty,
with our present knowledge, in foretelling a year in
advance whether the pressure will be in excess or
deficient.

Although this short-period \ariation of pressure is,
perhaps, the most important that is indicated in meteoro-
logical observations, and the reader can judge this from the
curves here shown, it is not the only one acting. In
many cases that have been examined, the most distinct
variations are those which extend over several years,
and correspond to the thirty-five year sun-spot variation
previously described, and to that covering about eleven
years. The prominence record is not sufficiently long
to say whether this class of solar disturbance has a
period of variation of thirty-five years, but the eleven-
year change is most pronounced.

The thirty-five year weather cycle, or Bruckner cycle,
as it is called, because Briickner was the fiist to clearly
demonstrate its existence, has for many years been sug-
gested. Thus Bacon many years ago wrote: "There is
a toy which I have heard, and I would not have it given
over, but waited upon a little. They say it is observed
in the low countries that every five and thirty years the
same kind and suit of years and weathers come about
again ; as great frosts, great wet, great droughts, warm
winters, summers with little heat, and the like, and they

Feb., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

call it the Prime." Again, in Australia there was
an impression as long ago as the year 1836 that the
seasons underwent a variation every nine or ten years,
varying, however, every third series or thirty years.

Now Bruckner has shown that there is a thirty-five
year period both in pressure and rainfall, the years of
high pressures corresponding to those of less rainfall.
This long-period variation is of very great importance
and must be reckoned with in long-period forecasting,
although it is not so prominent as the short-period

Lirves to
variation ot pres
type) and the mea
tics, over the wl

istrate the close relationship between the
i over the British Isles (Oxford taken as the
ainfall, from the Meteorological Office 5tatis-
; of Great Britain.

changes that have been described above. The accom-
panying set of curves (fig. 12) will perhaps serve to
illustrate this long-period variation of rainfall for a few
stations on the earth's surface, while the curve at the top
indicates the relationship between the epochs of the dry
and wet periods and those of the great solar variation of
thirty-five years described in a previous paragraph. It
must not be forgotten that to determine this long-period
variation from the rainfall records the means of several
yeari have to be taken together, and even when every
five-year values have been employed the resulting curves
have to be again " smoothed," as it is called. In some
of the cases it will be seen that the five-year means
render apparent the eleven-year variation, a variation
which seems more distinct in tropical regions, such as
India, than extra-tropical regions.

A glance at the curves is sufficient to indicate the
existence of these variations. From a study of these varia-
tions at many places scattered over the earth's surface, it
has been found that the maxima or minima do not occur
at the same epochs at all places ; at present this question
has not been worked out, but it may possibly turn out
that, like the short-period pressure variation, there is a
give and take between two large regions on the earth, in
which while the maximum rainfall is occurring in one
region the minimum is taking place in the other.

Fortunately for us who dwell in Western Europe, it
will be seen from the curves that we are entering on a
series of years, which, on the average, will be wet, after
having just experienced a number of years during which
the rainfall was very much below normal. The rainfall
of 1903 practically put an end to this long drought. It is
important to remember that the short period of about
four years is the most prominent variation of rainfall, and
is always at work. It is thus quite possible to have a
comparatively dry year when the long-period rainfall
variation is at a maximum, but on the average the wet
years will he wetter and the dry years less dry at such an
epoch. At the minimum of the long-period cycle the wet
years will be less wet and the dry years more dry.

Enough, perhaps, has been said to show that the rain-
fall variations all depend on the atmospheric pressure

changes that occur. These latter are apparently closely
associated with the solar cycles whether they be indi-
cated by spots or prominences. We are thus led to
deduce the most probable—and, after all, the most
natural —conclusion that the sun is the most important
factor in producing our varied weather.

We have become acquainted with three periodic varia-
tions of solar activity, covering about four, eleven, and
thirty-five years each. The question arises — .Vre there
any other variations of longer period which may help to
complicate the solar problem, and, consequently, the
meteorological one as well ?

It may be said, however, that no other periodic varia-
tion extending over a year has yet been traced, as the time
over which the observations extend is at present too short.

The lengths of the periods which have up to now been
discovered have, however, such a peculiar relationship to
each other that perhaps a means is afforded of suggesting
a fourth period. If we take the length of the shortest
period as our unit — namely, 3-8, and multiply it by 3, we
obtain 11-4, which is very near our second period, which
is 11-3; if we again multiply 11-4 by 3, we have 34-2,
which again is close to 34-8, the real value, as far as can
yet be determined, of the thirty-five period. Now, if we
multiply 34-2 by 3 again, we obtain 102-6, which may be
the length of a new period. The above numbers, put in

Fig. 12. Some curves showing the Iong=period variations of rainfall
and their relation to the 35=year solar chan.:e as indicated by the
vertical dotted lines, and the eleven=year solar period.

tabular form, show the curious relationship between the
periods perhaps better : —

3-8 X I = 3'8, value actually determined y8
3-8x3= 11-4 „ „ „ 11-3

3-8x6= 34-3 „ „ „ 34-8

3-8 X 9 = 102-6 „ ,, ,, ?

To advance the knowledge of weather changes, solar
variations must be most carefully watched. For a suc-
cessful solution of the weather problem, the two sciences.
Solar Physics and Meteorology, must go hand in hand,
and the saying "unity is strength" no less applies to
matters scientific than it does to o'.her a.Talri of lii'e.

KNOWLEDGE & SCIENTIFIC NEWS.

[Feb., 1905.

WsLter Finding with the
"Divining Rod."

As a result of I'rol. Wertheimer's announcement that
he was about to undertake some careful investigations
in the subject of water-finding by so-called " dowsers,"
quite a number of letters and articles have appeared in
the Times, showing how widespread is the interest
in this matter. These letters, too, when read as a
series, give a very good idea of how the question
stands. There are undoubtedly many people, and
many of scientific experience, who seem to be firmly
convinced that there is "something in it." Many of
these are themselves "dowsers," though unable to
assign any cause to the manifestations. Then, on the
other hand, there are those disposed to ridicule the
whole affair as an absurd superstition. But probably
the majority of thinking people are of a medium opinion
and are only anxious for evidence to convince them
one way or the other.

The case for the unbelievers is soon summarized.
There is almost as much evidence, as far as can be
ascertained, of failures to find the predicted spring,
as of successes. If one points haphazard to any
spot on the ground, and a well be sunk at that place,
there is a very good chance of water being met with.
This probability, combined with a due consideration of
the geological and topographical features, will be suffi-
cient to enable a professional water-finder to make a
good reputation. If he has the luck to hit off the
right spot his fame will soon be spread. If he fails, the
affair is soon forgotten.

But now let us assume that the mar\el!ous mani-
festations have been fully and truthfully recorded. If
certain persons, and only a limited proportion of man-
kind, possess the remarkable gift of being able to hold
a twig in their hands in such a way that it shall be
caused to violently rotate when held above a sub-
terranean spring of water, then we are undoubtedly in
the presence of an extraordinary force, the nature of
which is entirely unknown to us.

In searching for a solution of the mystery there are
two distinct propositions to be considered, since typical
"divining" is only supposed to be possible when two
factors are suitably combined. These are, a person
endowed with the mysterious power, and a forked stick
of certain dimensions and even a particular kind of
wood. Sometimes, however, it is said that a wire or
steel spring will do as well; while occasionally a
" dowser " will declare that he can even tell of the pre-
sence of water without anything more than his open
hand.

It is most unaccountable to suppose that a hazel twig
of a particular shape and size should be affected while
one of another sort of wood or slightly different form
should not be affected. And the fact seems so con-
trary to nature and so little supported by scientific
evidence, that we may, perhaps, dismiss this factor
from investigation.

Then, again, there has to be considered the method
in which the rod is held in the hands. It is usual to
hold it in one particular way, and herein, it seems to
us, is .some slight clue. It will be found that if a forked
stick of the usual dimensions be held in the orthodox
manner, that is, with the tips of the forks enclosed in
the palms of the upturned hands, a very slight move-
ment of the hands in a particular wav causes the base of
the fork to revolve right round, and thus an almost

unconscious pressure of the hands will often have an
extraordinary effect. This can easily be appreciated
by anyone even while sitting in one place and nowhere
near any water, holding such a stick and trying to keep
it pointing downwards, say for 10 minutes, on end.
It mav be, then, that a very slight convulsion of the
nerves causes the stick to move. In other words, it
seems probable that the divining rod is but an index
of slight nervous sensations.

Then as regards the power of watii -finding being
confined to certain persons. This, unless it be that
some people's nerves are more " highly strung " and
more susceptible to be affected than others, seems quite
contrary to all we know of the human frame. It is
much more likely that only a few persons happen to
have been successful, and are thenceforward supposed
to possess the extraordinary faculties. Undoubtedly
many people are exceptionally sensitive, for instance, to
atmospheric variations. Old wounds and corns fre-
quently indicate some change in the conditions quite
beyond recognition by our other senses, and this is a
subject that does not appear to ha\e been at all
thoroughly investigated.

We now seem to be arriving at a more rational
problem. The next question to be considered is as to
how the presence of a subterranean spring of water can
be detected by the nerves. It is a matter of everyday
occurrence to see, on still evenings, light mists hovering
over the grass in particular places, and it seems not at
all unlikely that such mists will usually be found
suspended above the position of some underground
spring. Is it, then, not probable that this patch of
humidity can be ascertained by instruments even when
the state of the atmosphere is not favourable to the
formation of a visible mist? ,\nd if the air in this spot
is different as regards humidity, temperature, or other
property to that surrounding it, is it not possible that
human nerves may be so affected that some \ery slight
difference is felt? And if this is the case it is not diffi-
cult to suppose that someone holding a twig in a con-
strained position might find that in passing into such an
atmosphere there was some slight relaxation or contrac-
tion of the muscles, and this would undoubtedly cause
the twig to revolve. One of the correspondents also
mentions how gnats are seen to congregate over par-
ticular spots. Whether this is due to dampness of air or
other cause has, we believe, not been well ascertained.

.Sir William I'reece, in the Ttnics of the i6th, brings
forward another theory. He suggests that the running
water may set up slight vibrations of the ground,
which, he thinks, may act upon " the sensitive ventral
diaphragm of certain exceptionally delicately-framed
persons."

But then we also read statements that the same
manifestations occur when, instead of water, a small
quantity of gold or other precious metal is present.
In this case we either feel that a very strong addition is
made to the case in favour of the whole matter being a
fraud or a delusion, or else that the mystery is one
altogether too profound for us to attempt to apply the
known laws of nature. One correspondent, indeed,
tells of "a respectable farmer in this neighbourhood
who could tell under which of several hats a sovereign
had been placed." We know of many people who can
do this, but without the aid of the di\ ining rod. There
is, however, much evidence as to the finding of lodes
of metal ore. .Another correspondent declares that he
himself can locate lodes of copper or tin ore, and has
done .so with great success. If metalliferous ores can
affect the hazel twig, the suggested theories of

Feb., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

humidity and vibration are quite inapplicable, and we
must search for some further cause. Some people
have vaguely ascribed the results to electrical mani-
festations, but ignorant people have a way of imputing
(often, perhaps, with some truth) all unaccountable
phenomena to electricity.

However, the subject is an interesting one and well
worth careful investigation, and as Prof. Wertheimer
has kindly promised to send us the results of his investi-
gations, we shall look forward with much interest to
the report. The Times suggests that " half-a-dozen
men of ordinary ability, powers of observation, and
common sense, could settle the whole question by
putting half-a-dozen ' water-finders ' to the test." If
they clearly proved the dowsers at fault the whole
question might be fairh- settled, but if the water should
invariably be found where predicted, the question would
be very far from being settled. We would suggest
that a beginning might be made, as it were, at the
other end; that is to say, to conduct some careful
scientific observations as regards the hygrometric,
thermometric, electrical, and vibratory conditions of
the earth and air at a spot beneath which a spring of
water was known to exist. If peculiar conditions were
found to exist, then we would know that there might,
after all, be something in human " water-divining."

CORRESPONDENCE.

TKe Great Red Spot of Jvipiter.

To THE Editors of " Knowledge."
Gentlemen, — In your note on p. 13 of the current number
of " Knowledge & Scientific News," you are good enough
to refer to some recently-published results by the writer rela-
tive to the motion of the above spot. May I, however, point
out that my observations and conclusions are in agreement
with those of Mr. Denning, and that they do not really " seem
to indicate very different results," as stated in your note ?
The rotation period found here for the red spot in 1902 is
g h. 55 m. 39'56 s., and for 1903 it is 9 h. 55 m. 4i"52 s.
Mr. Denning's figures for the same two years are g h. 55 m.
3g'4 s. and g h. 55 m. 40"8 s. re.^pectively (see the Observatory,
:go4, p. 343). It will be seen that both Mr. Denning's obser-
vations and those made here indicate a distinct increase in the
length of the rotation period. The shorter period of g h. 55 m.
38'6 s. ascribed to Mr. Denning refers to the first seven or
eight months of igo4, and seems to be due to further vagaries
in the motion of this truly remarkable spot.

Mr. Denning, I believe, observed the great hollow or bay in
the south equatorial belt of Jupiter, nearly opposite to the red
spot, whilst the spot itself was observed here. The periods of
time over which the observations extended are also probably
not exactly the same. These circumstances will probably
account for much of the not very large differences between
our figures quoted above. I believe that a shortening in the
length of the rotation period of the red spot for the first seven
or eight months of last year, similar to that pointed out by
Mr. Denning, will also be shown by my observations, but
these are still in progress, and I am anxious to avoid, as far as
possible, making any examination or comparison of the results
obtained until the close of the present apparition of Jupiter, so
as to avoid being biassed as much as possible. The Rev.
T. E. R. Phillips confirms, however, the more rapid motion of
the spot in the first seven or eight months of igo4 (sue Journal.
B.A.A., Vol. XV., p. 28). How far these somewhat curious
changes in the motion or drift of the red spot are real, and how
far they may be only apparent, and due to the changed sur-
roundings of the spot, must be left to future consideration.
A. Stanley Williams.
20, Hove Park Villas, Hove,
January 9, 1905.

ASTR.ONOMICAL.

A Sixth Satellite of Jupiter.

During December last, Professor Perrine, of the Lick Obser-
vatory, suspected the existence of a new satellite, but it was
not till early in January that observations made with the
Crossley reflector confirmed his suspicions. The distance
from the planet was much greater than that of any of the
other satellites, being then 45'. The motion of the satellite
was reported to be retrograde, presumably referring to its
apparent motion in the sky, and not to its orbital motion. It
has a magnitude of 14.

* * *

Observations of Meteors-
Systematic observation of meteors was conducted at
Harvard Observatory on November 14-15, four observers
watching while an assistant wrote down the records. In this
way 275 meteors were recorded. Though the heads at the
time of explosion were usually blue or white, in two cases at
least they were red or orange, which diff'erence in colouring is
ascribed by Professor Pickering to variation in chemical
constitution. Elaborate preparations were also made to
photograph the meteors, but only two trails were recorded on
the negatives exposed.

» * *

Eclipse Expeditions.

Three expeditions are being arranged in connection with the
Lick Observatory for observing the total eclipse in .August.
The cost of them will be borne by Mr. William H. Crocker.
One is to go to Labrador, a second to Spain, and a third to
Egypt. Photographs will be taken to endeavour to ascertain
the existence of an inter-mercurial planet in addition to the
photographing of the corona.

Death of Mr. Crossley.

The announcement of more important discoveries by
means of the Crossley Reflector at the Lick Obscrvatorj' has
just been followed by that of the death of the donor of that
great instrument, Mr, Edward Crossley. the Chairman of a
great carpet manufacturing firm of Halifax, Yorkshire.

BOTANICAL.

By S. A. Skan'.

The New Zealand Institute has lately issued Vol. XXXV. of
its Transactions, which, like many of its previous ones, con-
tains some important and extremely interesting papers relative
to the botany of New Zealand and the neighbouring islands.
We are reminded in Mr. W. W. Smith's communication on the
"Plants Naturalised in the County of Ashburton" of the
extraordinary number of alien species which have established
themselves in New Zealand. In Ashburton the naturalised
species number 368, of which as many as 95 per cent, belong
to the Scandinavian flora. Many of our familiar weeds are
abundant in this distant Colony, where they often flourish to
an extent rarely known in their native country. A thistle
(Cariiuiis lanccolatits), Mr. Smith tells us, grows so \igorously in
Ashburton that some places are rendered impassable, even on
horseback. The late Professor Kirk, writing in Vol. XXVIII.
of the Transactions, estimates the number of naturalised
species in New Zealand as over 500, and he described the

KNOWLEDGE & SCIENTIFIC NEWS.

[Feb., 1905.

remarkable effects on the indigenous vegetation'brought about
by their introduction. When Cook and Vancouver visited
New Zealand the constituents of the fauna and flora were,
Professor Kirk observed, very probablj' in much the same
condition as they had been in for many previous centuries.
Altered conditions following the immigration of white people,
the felling of forests, agricultural operations, and the introduc-
tion of various animals, many of which proved particularly
destructive to vegetation, rapidly made a marked impression
on the native flora. The clearing of the ground often meant
the practical extermination of indigenous species, while it
favoured the growth of aliens, seeds of which bad been intro-
duced in various ways, often mixed with agricultural seeds, in
ballast, or by means of animals. That the stronger-growing
species among the newcomers should spread and crush out of
existence the weaker native plants is not remarkable, but we
are told that the small slender-growing European grasses and
clovers have in places succeeded in displacing such stout
plants as Pliorm'uim tenax, the New Zealand Flax, and Cvpcnis
ustiiliitiis, a robust sedge. Rabbits and sheep have proved
disastrous to many species, especially those with very local dis-
tribution. Epilobiiim hnvifes, when Professor Kirk wrote, was
restricted to two localities, and could easily at any time have
been exterminated by a hungry rabbit or sheep. Cliniithiis
piniici'iis, a handsome leguminous plant, is now confined to one
or two small islands, where it owes its preservation to the
absence of sheep. Both writers have noticed that many of
the naturalised plants, after a period of remarkable vitality
and vigour, diminish in strength and numbers and sometimes
disappear altogether.

An account of a botanical excursion to the Southern Islands
of New Zealand is given by Dr. Cockayne. These islands
include the Auckland group, Campbell Island, the .Antipodes
and Bounty Islands. The visit was made during midwinter,
which enabled the author to note some previously unrecorded
features of the vegetation. In Auckland Island, at about
50^' 45' south latitude, a single specimen of a common New
Zealand tree-fern (Himitilhi Smilhii) was found. This is a
particularly Interesting discovery, for it considerably extends the
southern range of these plants. Hitherto the known hmit for
tree-ferns was about 47 south latitude, where, at Port Otway,
in Patagonia, A IsaphHapruiiuita has been met with. Both these
species may be seen in some of our botanic gardens. An
enumeration of the species native of the islands, with a full
bibliography, concludes a most valuable treatise on insular
floras.

* * *

SupraL-terrestrial Vegetation.

An article is contril>uted by M. \'irgile Brandicnurt to the
Ke.vur. Scientifiqiie on " supra-terreslrial " vetjct.-ilion, plants
which grow, not on the surface of the earth, but on w.iUs,
;tnd roofs, and trees. They form an interesting study.
The oldest of them are those that grow on stone and brick
walls. Sixty-seven per cent, of these are plants with I'ne
seeds (saxifrage, arenaira, urtica. &c.), 13 per cent, plants
with winged seeds, that are easily dispersed by the wind,
9 per cent, plants with fleshy fruits, 6 per cent, plants with
hooked seeds, and 5 per cent, plants with an explosive
mechanism for dispersing the seeds. The plants of thatched
roofs are also numerous. Some of the older thatched
roofs have from 15 to 16 species of plants, and the general
average is eight. There is a special flora characteristic of
the tops of pollard willows. As many as S6 species have
been catalogued which grew thus. The most curious
instance of a parasitic tree was communicated by Dr.
Magnin. A mulberry tree took root on an ash, and usurped
its place by pushing the ash's* trunk down little by little till
it was lost to sight.

METEOROLOGICAL.

Meteorological Figures.

.\n attempt is made by Dr. Kiippen, in the German
meteorological review Das IVrflcr, to express a mathemati-
cal relation between the intensity of heavy rainfall and the
time which it lasts. Me makes out a constant " n " for the

relation, " n " being equal to the square root of the time
multiplied by the intensity. By a curious coincidence the
French meteorological review, Le Temps qu'il Fait, has an
article on recorded great falls of rain, or, perhaps, we should
say great " cloudbursts." On August 20, 1900, 30 mm.,
or well over an inch of rain, fell at Maredsous
in ten minutes. The greater rate of fall recorded was,
however, at Turnhout on July 10, 1899, when 25 mm., or
nearly an inch, fell in six minutes, wliioh gives a rate of
4.2 millimetres a minute. In these heavy rainfalls the
distribution is very erratic. Thus, on .\ugust 27, 1902,
during a storm which swept Paris, 50 mm., or not far from
two inches, fell at the Pare des Buttes, Chaimiont, and less
than a auarler of an inch at Mont .Souris.

The Velocity of the Wind.

At the Eiffel Tower, during a storm on the night of the Tith-
12th of September, igoj, a rate of 42 metres a second (94
miles per hour) was recorded, but this record was eclipsed in
1S94, when on the 12th of November the wind attained a velocity
of 4S metres per second. America, however, cannot be beaten
in such matters. On the i8th of May, 1902, a storm vi-^^ited the
Pacific Coast, and near San Francisco the wind was measured
as travelling during several minutes at a speed of 53-6 metres a
second. Since the velocity undoubtedly as a rule increases
with altitude, it is not surprising to find that on the summits
of high mountains still greater speeds have been recorded.
M. Brunhes, the Director of the Observatory on the Puy de
Dome, claims the record wind velocity, for on the gth of
December, 1901, between 10.20 and 10.30 it blew at a mean
rate of no less than 70 metres a second, or 156 miles
an hour.

» « »

London Fogs.

The report of the Meteorological Council upon "an Inquiry
into the Occurrence and Distribution of Fogs in the London
Area, during the Winters of 1901-2 and 1902-3 " has just been
issued. It is, of course, past our understanding why such a
report .should take nearly a year to compile, but we must rest
satisfied that such tardiness is not unusual with similar reports,
and that doubtless there was good reason for it. During the
last winter observations of the fog were recorded at 46 stations,
and thermometers were supplied to thirty fire brigade stations,
in order to determine the variations of temperature prevailing.
Among the various supposed causes of fog, radiation from the
earth's surface diuing calm nights is found to account for the
m.ajority. Warm air passing over previously cooled surface
causes many others, while " cloud fogs " form a third class.
There is no evidence to show that, in London, geological for-
mation affects the formation of fogs, and while fogs on the river
and in the open parks were frequent, it has not been found
that the neighbouring districts were specially infected.

As rrgards forecasting the presence of fog, it is pointed out
how much more valuable night observation and early morning
reports would be than the present system of issuing the fore-
cast at 6 p.m.

OR.NITHOLOGICAL,

By W. P. PvcRAFT, A.L.S., !• ./...S., M.B.O.U., &c.
Flanningoes on the Medwa.y.

Thk l-'irlil. Dec. 24, r(|)orts the occiurcnce of flamingoes
— presumably I'lucnicoplcrus rosfiis — on the Medway. A young
male " was recently shot on the marshes close to Gillingham,"
and mistaken by the shooter for some kind of goose! It is
reported that another has been seen.

Although there can be no doubt that some of the re-
corded occurrences of this species should be cancelled as
escaped birds, at least three previous instances of wild birds
taken in this country must be allowed to stand. Nevertheless,
so good an authority as Mr. J. E. Harting refuses to admit the
Flamingo to the list of British Birds.

Feb., 1905

KNOWLEDGE & SCIENTIFIC NEWS.

The Breeding of the Knot.

The Ihis for January contains a short but interesting account
of the' discovery of the hitherto unknown eggs of the Knot
{Trini^a canutus). A uest of this species, containing four eggs,
was found on June 17, iSgS, in the Island of Hriscy, to the
north of Iceland. The bird was breeding with several pairs of
rr»;,;'i; inaritiDia — the Purple Sandpiper — and was kept under
close observation for some time before the eggs were taken.
It was not killed, as the collector hoped to have the good for-
tune to obtain a second clutch.

The eggs are described as " quite like very large eggs of the
Dunlin (Tyin:^a nlpiiui), of the closely-spotted type, and cannot
be confounded with any others of the same size."
* * *

The Pacific Eider at Scarborough.

An adult male of the Pacific Eider, Soiiuiti-riii \''iui;rd was
killed during December at Scarborough. This is the first
authentic instance of the occurrence of this bird in Great
Britain. Closely resembling our common Eider, S. luolisaiiua,
it may be distinguished therefrom by the V-shaped mark on
the throat, and the bright orange colour of the bill.

The Pacific Eider is found in great numbers in North-Wes-
tern America and North-Eastcrn Asia.

Peregrins Falcon in Essex.

.'\ fine female of this Falcon {P'liUa pi'i-txi'inus) was killed at
Tambridge, l^ssex, during the first week of January. It is a
pity that these handsome and rapidly-vanishing birds cannot be
protected more completely.

PHYSICAL.

More Failures with N-Ra-y Experiments.

MM. Chanox and Perrigot have been attempting to repeat
an experiment made by M. Bordier, who showed that N-rays
emitted by tempered steel could apparently be detected by
photography. The former, however, found that equal sized
pieces of .steel and of lead, placed on exactly similar screens,
and exposed for various periods, never gave different halos, as
described bv M. Bordier.

» * *

Solid Electrolytes for Accumulators.

The usual acidul.ited liquids employed in accumulators have
many disadvantages, especially when the cells are carried m
motor vehicles or in other circumstances where they may be
subjected to much shaking and vibration. The liquids are
liable to be spilt or to penetrate through stoppers and corrode
the terminals or wires and cause other annoyances. For
this reason they have sometimes been replaced by pastes or
jellies.

M. Schoop, who has lately been experimenting in this line
in France, gives the following preparation as one very suitable
for the purpose.

1. A solution of sulphuric acid in distilled water, having a
specific gravity of I'zz.

2. A solution of silicate of soda, free from chloride, in dis-
tilled water, with a density of i'20.

3. A " bouillon " obtained by boiling for two hours in an
enamelled receptacle one kilogramme of asbestos card with
two litres of water acidulated with 10 per cent, of sulphuric
acid. The cardboard disintegrates and is washed over a filter
with distilled water, and is then squeezed as dry as possible
by hand so as not to retain more than one-third its weight of
water. Take iS litres of the acid solution No. i, add 450
grammes of the wet asbestos fibre, and thoroughly mix in a
glass or ebonite vessel. Rapidly pour in 4J litres of the
solution No. 2, and stir until it assumes an oily appearance.
Then pour the composition into the accumulator, the plates
having been moistened with acidulated wafer, and leave for
24 hours to settle. The liquid gradually thickens, and finally
becomes a solid jelly.

ZOOLOGICAL

By K. Lvi

The Position of the King Crab.

According to Professor E. Ray Lanke.ster, who has been
lately discussing its affinities and systematic position, the
King Crab (Liniulus) of the Moluccas is a misnamed creature ;
for, in spite of its somewhat crab-like shell, it is not a crab at
all, but rather a near relative of the scorpions, which are first
cousins of the spiders, and are consequently included in the
class Arachnida — a group of equal rank with the Crustacea, or
crabs, lobsters, &c. The extinct trilobites, which have also
been classed as crustaceans, are likewise included by the
same authority in the Arachnida, of which, however, they form
a brigade of equal rank with the one comprising all the other
members of the class.

* * *

The Coloration of Animals.

In a paper on coloration in mammals and birds, by Mr. J. L.
Bonliotc, recently published in the Journal of the Linnean
Society, the author suggests that colour in the members of
these groups is primarily due to activity of nutrition and
function, or, in other words, "vigour"; and consequently that
where conditions are favourable to a high state of vigour in
animals, there the majority of species will be brightly coloured,
and, of course, vice versa. Vigour he believes to be dependent
on two chief causes, namely, climate (which is taken to include
both temperature and food) and the rise and fall of sexual
activity. In polar regions, where the two causes operate
together, the changes are violent; in the tropics, on the other
hand, the eft'ect of climate is practically nil, and changes in
colour are consequently due in the main to sexual causes.
The occurrence of dark-coloured animals, like the musk-ox, in
arctic climates is explained by special specific vigour. The
"bleaching" of the hair of mammals and the feathers of birds
is regarded as an active process, and not merely the effect of
" weathering."

Natural selection and protective coloration take, in the
author's opinion, a secondary position, because, although un-
doubtedly important factors, they are only able to make use
of such colours or to modify such markings as have been pro-
duced bv vigour.

* * *

Papers R^ead.

The most important event at the meeting of ihe Linnean
Society, held on December i, 1904, was a discourse by Pro-
fessor S. H. Vines on proteid digestion in animals and plants.
At the meeting of the same Society on Decemlier 15, Mr.
C. C. Hurst communicated notes on heredity in rabbits, based
on crosses between a Belgian "hare" and an albino Angora;
and on January uj Dr. W. G. Ridewood read a paper on the
osteology of the skull in the bony fishes of tlie families Ost:o-
glossidcp, rantodontidiV, and Pliractohcmidcc. At the meeting of
Ihe Zoological Society on December 13, Mr. O. Thomas ex-
hibited skins of a gazelle from Palestine, which he regarded as
indicating a new species. The important feature of the meet-
ing was, however, the exhibition by Mr. Rothschild of a large
series of mounted skins, skeletons, and skulls, illustrative of a
paper on the man-like apes, in the course of which the author
described the gorilla of the South Cameruns and the white-
faced chimpanzi of the Gabun as new. Dr. Ridewood con-
tributed a paper on the skulls of the herring-like fishes, Pro-
fessor Minchin discussed the British sponges of the genus Lt-»ro-
snleiiia, Mr. Blanford described a number of land-shells of the
genus Macrochlamys and allied types, and a communication
from Mr. M. Jacobv was read containing descriptions of beetles
of the family Halficidu from South and Central America. At
the meeting of the same Society held on January 17, Mr. W. !•'.
Lanchester contributed three papers dealing with annelids
and other invertebrates from the Malay Peninsula and
Zanzibar ; Mr. A. D. Jenner discussed the minute teeth on the
palate and gullet of sharks and rays; and Mr. Beddard read
one paper on the anatomy of the Australian frilled lizard
(Chlamydosaurus) and its allies, and a second on the brain of
the black ape [Cynopithccusniger) of Celebes.

KNOWLEDGE & SCIENTIFIC NEWS.

[Feb., 1905.

REVIEWS OF BOOKS.

Biocheraistrj' of Muscle and Nerve. \V. D. Halliburton,
M.D., F.R.S., pp. 160; price 7s. 6d. net (London: John
Murray, 1904.). — This book consists of a reprint cf two courses
of lectures delivered in London and the Herter lectures
delivered in New York. For the material of the book we have
nothing but eulogy, but the arrangement leaves something to
be desired. The book is really a republication of experimen-
tal lectures, and in the book Dr. Halliburton describes experi-
ments which he was actually performing in the lectures. The
reader of the printed pages cannot, however, see the perform-
ance of the experiments, and finds it a little exasperating to
read : " Let me now show you with this other freshly-killed
rabbit another way of making muscle plasma. . . . The
iron lemon-squeezer is very effective for the purpose. You see
the drops of muscle plasma." . . . And so on. Surely it
would not have taken a great deal of trouble to alter the tense
when preparing the lectures for press. This is our only
adverse criticism, for the rest we hardly know where to begin,
the book is so interesting. The first lecture is more or less
introductory, and opens with an account of the composition of
the muscle. A description is given of the manner in which
proteids can be separated from each other, in the first place
by fractional heat coagulation. This was demonstrated before
the audience in the case of muscle plasma, the first coagula-
tion taking place between 42° and 47', the second coagulation
at 56". Another method being that of salting out with
ammonium sulphate. '■ Thus half saturation with ammonium
sulphate (one of the most frequently employed of the neutral
salts for the fractional precipitation of proteids) will preci-
pitate globulins; complete saturation with this salt is neces-
sary to precipitate albumins." Lecture II. deals with heat
rigor. A muscle loses its irritability and contracts permanently
when gradually heated to a certain temperature, this being
due to the coagulation of the proteid material of the muscle.
Diagrams are given showing that the contractions at different
temperatures correspond to the coagulation temperatures
of the various proteids. Chemists will find Lecture IV. one of
the most interesting. It treats of the " extractives and salts of
muscle." It should also interest athletes, because the author
refers to the feeding of those in training, and explains that,
although muscle works most economically when chiefly fed on
proteids, during recent years feats of great endurance
have been carried out by men fed mainly on carbohydrates.
Most readers will probably remember the feats of marching
undertaken by the German Army upon a food consisting of a
few lumps of sugar or of chocolate. It appears, therefore,
that a more or less mixed diet is probably the best. " Meta-
bolism in Nervous Tissues" is the title of the seventh lecture,
and is illustrated by a number of very useful diagrams. The
study of the metabolic activity in nervous tissues involves the
discussion of fatigue and sleep. It is interesting to note that
whereas large doses of carbonic acid act upon the nerves as
an ana;5thetic, and therefore abolish electrical response, small
quantities increase its activity. " A nerve thus forms a very
deUcate test object for this gas; far more delicate, in fact,
than most chemical reactions are." Another point of interest
is the demonstrable fact that fatigue takes place in the nerve
centres and in the peripheral endings of nerve fibres, but the
nerve fibres themselves appear to be non-fatiguable. The
book interests us so much that we are tempted to give quota-
tions from nearly every page. This would not be fair to the
author, and the Editors of Knowledge would probably object
from reasons of space. Every medical man and others who,
although not having special medical training, have scientific
training, should read this book. The author knows how to
bring out the salient parts of his subject with incisive clear-
ness, and the fact that so much of the work has been carried
out by himself and co-workers adds very greatly to the value
of the book.

Bacteriology and the Public Health. By George Newman,
M.r^. Third edition : John Murray. — There are so many
points of contact between public interest and the science of
bacteriology that a book which views the present knowledge
of bacteria from the standpoint of public health has claims to
consideration from every side. It is in the highest degree im-
portant that scientific men who have the ability to do so should

j present to the popular mind in a clear and convincing manner
' the bacteriological processes on which we rest our treatment
of some diseases, our sanitary measures and precautions, and
our scientific treatment of food stuffs. To take one example
from several others in Dr. Newman's chapters, there is the
question of immunity from disease. The bacteriological prin-
ciple of immunity, divested of the many complexities with
which Ehrlich and Welch and others have sought to clear up
certain diificulties and contradictions, is briefly this : That
when the blood is infected with any bacterial poison a specific
antidote is detached from the blood's corpuscles to combat the
poison ; and that this antidote remains in the blood after the
poison has been met and vanquished. Thus in order to culti-
vate the antidote we infect the blood with a mild dose of
poison, and the blood in response prepares a quantity of anti-
dote which will resist the onset of the poison if it should
appear in large quantities. It is on this principle that we
vaccinate as a preventive against smallpox ; that we vaccinated
with a sort of broth of typhoid bacteria, in order to preserve
our soldiers in the South African war from enteric ; that we
prepare a serum in the veins of the horse as an antidote
against diphtheria ; or that we tried to find an antidote to the
poison of the tubercle bacillus. Some of the processes by
which immunity' can be artificially secured from such treat-
ment of the blood have been successes ; some have been
failures; and some, though believed by scientific authorities
to have the germs of success in them, have excited profound
public mistrust. In the case of one method, that of anti-
typhoid vaccination, the distrust among soldiers and sailors
was sufficiently manifest to make the Government abate the
use of Professor Wright's vaccine, probably because they felt
that its continued use might prejudice recruiting. That was
a quite legitimate exercise of caution on the part of the
Government ; and they might also plead on behalf of their
action (though Professor Wright has produced figures which
strongly support his contention that the vaccine is efficacious)
that bacteriologists are divided in opinion concerning the
Wright vaccine. It is maintained by some that his method
of sterilising the bacteria does not extract, as it were, the
intra-cellular poison in efficacious proportions. But whatever
may be the truth about this particular remedy, it is of the
highest importance that the public should approach these new
methods of treatment with understanding and without pre-
judice. Dr. Newman's book is not a text-book; and it does
not treat this subject very fully. It rather presents con-
clusions than justifies them. We call attention to this par-
ticular brevity in the present edition because we should like
to see it remedied in a future one, for we believe that there is
hardly any question which, in the public interest, should be
made more clear to them than the principles on which the
bacteriological treatment of disease rests. But if in the one
instance we have chosen Dr. Newman appears to err on the
side of conciseness, we cannot refrain from expressing our
highest admiration for the masterly digest he has made of the
many subjects of the highest public importance which are
bound up with bacteriology, and for the extremely able manner
in which he has presented the very latest information and
theories in respect of them. Among the subjects, as amply
illustrated as summarised, are Bacteria in Air and Water, the
Bacteriology of Sewage, Bacteria in Milk, Bacteria in Foods,
Tropical Diseases, Tuberculosis Immunity, and Anti-toxins
and Disinfection. The earlier chapters are a .summary of
bacterial biology and theory.

Birds of Russian Lapland, by Henry J. Pearson, Mr.
Pearson is a most enthusiastic ornithologist, who has
made the north of Europe for many seasons his hunting
ground. His ardent search for the nesting places of birds
has led him into many wild countries in northern regions. A
few years ago some of these journeys and their results were
described in " Beyond Petsora Eastward," and " Three
Summers among the Birds of Russian Lapland " may be called
a sequel to that volume. The work of three seasons included
that of i«t)fj, when the author visited the coast of Russian
Lapland; that of kjoi, when he voyaged to the Kanin
Peninsula on the cast side of the White Sea ; and that of 1903,
when the interior of Russian Lapland was visited. The book
is arranged in the form of a diary; its contents will be
especially valuable to those interested in the species of birds
which nest in the north, many of which — such as fieldfare.s,

Feb., 1905]

KNOWLEDGE & SCIENTIFIC NEWS.

redwings, ducks, geese, and waders — are familiar visitors to
England in winter. The last chapter of the book deals with
history rather than natural history, and is devoted to St.
Triphon, •' the enli,t;htener of the Laplanders," and the
monastery founded by him on the Pechanga River in North-
western Russian Lapland. Mr. Pearson's work is profusely
illustrated with reproductions of the author's beautiful photo-
graphs. There are 68 full-paged plates in all. Besides the
many charming photographs of the birds and of nests and
eggs, others illustrate most effectively the country and the
people, and others the flora. Mr. Pearson is much to be con-
gratulated on compiling so fine a record of his wanderings in
these wild and barren, but fascinating, regions.

The Process Year Book for 1904-3 (Penrose and Co.; 4s.)
comes out as a handsome volume, replete with hundreds of
beautiful illustrations in all styles, of which 54 are in colour.
This is the tenth year of issue, and it may well be supposed
what an interesting exhibition it forms of the progress made
in this art. To quote from the preface : " Ten years is a short
period as history is made and measured, but it has been long
enough for process workers to achieve a great deal. Few
modern industries have progressed at such a rapid rate, and
few have so rapidly and completely revolutionised or super-
seded older methods." A number of mteresting articles by
well-known experts in the various branches of process print-
ing complete this valuable history.

Dyes and Stains and Polishes. — In " Dyes, Stain.s, Inks, Var-
nishes, Polishes, iSc. including the art of Wood-staining,
Filling, and I<"rcnch Polishing, Briefly, but Sufficiently and
Clearly Explained" (Dawbarn and Ward), the author, Mr.
Thomas Bolas, sufliciently and clearly, if not briefly, explains
the contents and scope of his small sixpenny handbook. It is
intended for the beginner, and it is terse and far from being
overloaded with detail.

The Elements of Geometry, by Braithwaite Arnett (Simpkin,
Marshall and Co. ; price zs. each part). — Geometrj' does not
change much with the times, yet new books periodically app;ar
to instruct us in the old science. In the three small volumes
before us there is certainly some novelty. A good deal not
usually included in such works is introduced. Trigonometrical
ratios, comparative scales, points of the compass, even ther-
mometer scales, are briefly but clearly gone into, and in the
more minor details of bold and simple diagrams and large type
a decided improvement on many older text books is effected.
It almost seems a pity that more changes are not made. For
instance, many definitions, which, though strictly according to
custom, are in reality very useless in modern instruction.
Take No. 16, " When a straight line is drawn between two
given points which are its ends, it is called a finite straight
line." It is not, in common parlance, called a " finite straight
line," and if it was, that would surel}' be a sufficient descrip-
tion. So, also, it seems rather unnecessary to lay down that
" a rectangle has all its angles right angles."

"The Elements of Trigonometry, by S. L. Loney (Caml)ridgc
University Press; price 3s. 6d.), may be criticized in much the
same way as the foregoing. There is nothing exceptionally
new in this small book, which is intended for the use of
students commencing Trigonometry, but the subject is simply
and clearly put, and heavy type introduced to emphasize
special points.

" Stories from Natural History," by Richard Wagner. Trans-
lated from the German by G. S. (Macmillan ; is. 5d.). — This is
a most excellent little book for children, calculated to awaken
their interest in animals and to encourage their powers of
observation. Ouite short accounts of different animals are
simply given, and these are well illustrated from photographs.
How to Build a Bicycle, by Mr. R. H. S. Williams, and How to
Build a Petrol Motor, by Mr. James F. Gill, B.Sc, are the
titles of Nos. 4 and 3 of the " Home Worker's Series " (Daw-
barn and Ward ; 6d. net). They are simply written and practical
handbooks, specially adapted for use by amateurs. "Toning
Bromide," by Mr. R. E. Blake Smith, is the subject of No. 16
of the "Photography Bookshelf Series" (Iliffeand Sons). The
author's name is familiar to photographers through the method
of sulphide toning introduced by him. This method is dealt
with in the present volume, and the author gives besides
detailed descriptions of other methods of modifying the
colour of bromide and other developed silver prints.

Astronomy. — The appearance of a third edition of the admir-
able and fascinating book by Mr. Walter E. Maunder, F.R.A.S.,
" Astronomy Without a Telescope " (W. Thacker and Co.)
is interesting, not only as a tribute to its great and well-
deserved popularity, but as proving the existence of a large
and increasing number of persons who take an intelligent
interest in the study of natural phenomena.

Astronomy for General Readers (Whitlaker and Co.), by Mr.
George F. Chambers, F. 1\,A.S., is re-published in a cheap
edition at the price of one shilling, whereby a useful and read-
able book is brought within the means of the general reader
of popular science.

Fireside Astronomy (Witherby and Co. ; price is. 6d. net)
by Mr, D, W. Horner, F.R.Met.Soc, M.B.A.A., is intended,
as its title suggests, to meet the requirements of the intelligent
amateur, who, having neither the lime nor the means for a
serious study of the subject, would yet be very glad to know
in a general way something of the science of astronomy.

Examples in Arithmetic (George Bell and Sons; with or
without answers, 3s.) is compiled by Mr. Charles Pendlebury,
assisted by Mr. F. G. Robinson, from his " New School Arith-
metic." The examples range from elementary to advanced
arithmetic. Part II. including elementary mensuration and
logarithms.

" Hints on Collecting and Preserving Plants " (West, Newman, .
and Co. ; price is.), by Mr. Stanley Guiton, contains useful
hints for the formation of a herbarium by a young collector,
and gives advice respecting the best means of collecting,
drying, preserving, and arranging plants.

" The Hygiene of Bird-Keeping," by Mr. W. G. Creswell,
M.D., L.R,C,P., F.Z.S. (R. G. Clement; price is. net), consists
largely of articles which have appeared in " Bird Notes."
It gives practical and sensible hints on the housing and feeding
of birds.

" Christianity and Rationalism on Trial " (Watts and Co. ;
price 6d,) is the title of articles by various authors con-
tributed to the Clarion in the course of a controversy which
took place in the pages of that journal on the subject suggested
by the title.

"Do We Believe " (Watts and Co.; price 6d.), by Mr. John
Allan Hedderwick, summarises a correspondence which took
place on the subject of" Belief" in the columns of the Daily
Tclixi'iipl', and attempts to show what, in the author's opinion,
are the foundations of a stable belief.

"Christianity and History," by the Rev. J. Neville Figgis, and
" Britain and Her American Colonies," by Mr. E. and S. Hors-
burgh (James Finch and Co.; 2S. net) are two of a series of
small volumes published with an educational purpose. They
are primarily intended as the subjects for essays or holiday
tasks; and examination papers by the respective authors can
be supplied to teachers at 5s. per 100 copies. The subjects
dealt with are treated in a readable and popular style.

"Italian Varnishes." — Mr. George Fry, F".L.S., F.C S., be-
lieves himself to have solved the long-vexed problem of the
varnishes used by the great Italian masters of violin-making.
The results of his study and experiment are given in his book
on "The Varnishes of the Italian Violin-Makers of the Six-
teenth, Seventeenth, and Eighteenth Centuries, and their In-
fluence on Tone " (Steevens and Sons; price 6s.). Hitherto
experts who have had facilities for examining the varnishes on
old Italian instruments have believed it to be an oil varnish
coloured according to the fancy of its individual makers, and
divers explanations have been offered to account for the
inability of modern violin-makers to reproduce it. Mr. Fry
suggests as the explanation of the problem that the old violin-
makers used as the constituents of their varnishes the natural
products of trees (conifers) and plants (flax) growing in their
immediate vicinity; that they were simple varnishes composed
of resin and turpentine, or of these two substances and linseed
oil; and that the various apparent colours were due to optical
effects naturally arising from variations in the details of the
preparation of the varnishes. We can only say, without
seeing and hearing the results of Mr. Fry's experiments,
that the arguments used by him in support of his_ asser-
tion, and his descriptions of the experiments made by him, are
exceedingly interesting, and worthy of attention.

KNOWLEDGE & SCIENTIFIC NEWS.

[Feb., 1905.

Cnj'Juctfd h'l F. Shillington Scales, f.r.m.s.

Fibrous Constituents
of Paper.

Paper is generally understood to be made from
"rags." This is, however, only partially true, as
papers maj- be considered to be roughly divided into
two classes : white printing and writing papers, of
which only certain of the writing papers have much
rags in them; and coarse wrapping and bag papers,
including brown papers, which are almost entirely
innocent of rags. Of late years in particular a revolu-
tion has taken place in paper-making by the use of
wood-pulp. Twenty years or so ago the use of wood
was limited to what is known as " mechanical wood-
pulp," short broken fibres torn from logs by means of
some grinding apparatus, and it was considered im-
possible for satisfactory fibres with good " felting "
properties to be obtained from so stiff and intractable
a substance as wood. Then came the introduction of
chemical wood-pulp, in which the logs of wood have
been treated by the soda bisulphite or sulphate pro-
cesses, the result being soft white fibres which are now
more largely used in paper-making than any other
material.

The testing of a sheet of paper is, in England, almost
entirely a question of experience. Colour, feel, hard-
ness, absorbent properties, strength, freedom from dirt,
specks, and other imperfections — all these are decided
by looking at and handling the paper only, and the
buyer would probably be much puzzled if it were
suggested that he should make a microscopical
examination of the papers he had bought. The result
is that there is in England no standard of comparison
by reference to which disputes as to qualitv may be
readily settled. In Gcrinany, on the other hancJ, at
Charlottenburg, there is a Government Laboratory for
the sole purpose of testing papers, not only those used
by Government departments, but any others which may
be submitted. This does not necessarily show, how-
ever, that such a laboratory is needed here, for
whilst a more uniform set of standards might be
of service, the requirements of various papers vary
-so greatly that rigid, inelastic tests may easily be very
misleading.

The microscopical examination of paper, however,
limited, as it generally is, to the ascertaining of the
fibres of which the paper is made, has no such dis-
advantages other than those due to the necessity for
training and experience in such a matter, and it is a
matter of surprise that this branch of paper-testing has
not received more attention in this country. It may be
of interest to many of the readers of these columns if I
endeavour briefly to explain the methods of recognition
of the various fibres, avoiding as far as I can all
technicalities.

(Tn !•> i-fntinued.)

Royal Microscopical Society.

/\t a mcetiiii; lulil on I )rt'i'ml)or Ji at jo, Hanover
Square, Mr. G. C. Karop in the chair, Mr. Conrady read
a short paper explaining .in experiment he exhibited to
prove the phase-revers;il in the second spectrum from a
grating of broad slits, the mathematical proof of which
was given in his paper on " Theories of Microscopical
\'ision," read before the Society at its last meeting.
The object consisted of two gratings, one above the
other, similar in e\cry respect except that one had
broad and the other narrow slits. In accordance with
what was theoretically predicted by the author, the
difference was brought out when the direct light plus
the first and second spectra of one side were admitted,
but when the direct light was cut off by the movement
of a shutter the image of the broad slits underwent a
startling change. The lines jumped across to positions
midway between the correct ones, showing there was
an antagonism of phase between the light of the first
and that of the second spectrum. Sonic photographs
were exhibited bv Mr. Rhcinherg which showed the
effects produced by cutting out the various spectra of
one side, and he suggested to Mr. Conrady that the
experiment should be made to test the correctness of
the theory. Mr. J. W. Gordon then gave a summary
of his paper " On the Theory of Highly Magnified
Images," and illustrated his remarks by numerous dia-
grams shown on the screen. A discussion ensued in
which Messrs. Rheinberg, Beck, and Conrady took
part, and Mr. Gordon briefly replied.

The Quekett Microscopical Club.

'I'lie .(iSth ordinal-}' ineeling of the Club was held on
December 16 at 20, Hanover Square, W., the Presi-
dent, Dr. E. J. Spitta, V.P.R..\.S., in the chair. After
the ballot had been taken for the new members, the
President announced that fifty members had been
elected during the p;ist year, and congratulated the
Club upon the increase, which he hoped would be full\
maintained in the future.

Mr. C. G. Curties, F.R.M.S., exhibited and described
the new Nernst electric lamp arranged for use with the
microscope, and also one of Baker's " Diagnostic "
microscopes, a model combining extreme portability
with firmness.

Mr. D. J. .Scourfield, F.R.M..S., gave an interesting
lecture on " Fresh Water Biological .Stations," illus-
trated by lantern \iews of the exterior and interior of
the principal fresh water biological stations in Europe
and America. He pointed out that they had their
origin in the general deepening of biological research
which followed the establishment of the Naples and
other marine biological stations, between the years
1870-1890, aided by the rise of Limnology, which in
itself was largely due to Professor F. A. Forel, who
had shown by his work on Lake Geneva what might be
done by a systematic study of lakes. The first fresh
water biological station in England was started in
1902 at Sutton Broad, Norfolk, by Mr. Eusfacc
Gurney, anfl although the station was as yet but little
known, it had already been the centre of good work,
and deserved every encouragement.

Improved Methods of Working with the
Vertical Illuminator.

I am indebted to a correspondent for the following
methods of using the vertical illuminator : —

Feb., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

Method I. — With the image of a stop. Method II. —
With the stop and the vertical illuminator.

The accessories necessary for Method I. are (i)
source of light ; (2) carrier for stop ; (3) condenser ;
(4) vertical illuminator. The condenser is first set
between the light and the vertical illuminator, so that
it forms an aerial image of the source of light at a
distance from the vertical illuminator equal to that
from the vertical illuminator to the top of the eye-
piece. The carrier for the stop is then placed between
the light and the condenser in such a position that its
aerial image is exactly adjusted and falls sharply in
focus at the back lens of the objective. This will give
an effect precisely the same as placing a stop or
diaphragm over the vertical illuminator itself, while the
upward path of the rays from the object to the eye is
unimpeded.

The accessories necessary for Method II. are
(i) source of light; (2) bull's-eye condenser; (3)
vertical illuminator with stop or diaphragm fitted to its
side. For this method, the lamp and bull's-eye are
adjusted as in Method I., care being taken that proper
distances are kept, when the same effect will be pro-
duced as with a stop or diaphragm placed immediately
over the vertical illuminator.

New Vertical Illuminator and New
Monochromatic Trough.

Messrs. R. and J. Beck, Ltd., have brought out a
new vertical illuminator of the prism type fitted with an
iris diaphragm beneath the prism for cutting off out-
side light, and a plate of stops so arranged that the
position of the beam of light impinging on the prism
can be varied until parallel light of the right angle is
obtained. The vertical illuminator is largely used now
to illuminate the surface of metals when making
metallurgical examinations with the microscope. The
principle is that a beam of light sent at right angles to
the optic axis of the microscope is reflected by a prism

or piece of cover-glass down upon the object so that
each objective acts as its own condenser. It is probably
the only means of illuminating objects mounted dry
when they are examined with immersion lenses, though
in this case it is necessary that the object should be in
actual contact with the cover-glass.

The trough is noticeable for its compactness and
easy adjustability. It can be brought as low as one
inch from the table or raised to a height of nine inches.
The fluid used in the cell depends upon the required
colour of the light.

Notes and Queries.

Examination of Water.

Johti Ciin-iiigtoit, East London, S.A. — I do not thinU you
•-vould find anything in town-water unless it was very bad.
Under any circumstances a Botterill's trough would not do,
as the thickness of the glass and the depth of the cell would
prevent your using a high enough power. I would suggest
your getting a sample of water from a stagnant pond or old
tub, taking up a few drops with a glass tube, and by examining
it in an ordinary excavated cell, covered with a thin cover-
glass, you will find enough to interest you there. The weird
animal life exhibited sometimes in a drop of water at lectures
has, I am afraid, been specially selected to astonish the
audience.

Deane's Medium.

Mr. T. H. Russell, of Birmingham, would be glad to know
if any reader of these columns has had any experience of
Deane's medium for mounting vegetable specimens for the
microscope. He says he has been in the habit of mounting
his mosses in glycerine jelly, but, like most people who use it,
has found it somewhat treacherous. He has found Deane's
medium more reliable in some ways, but it has a tendency to
shrixel up certain specimens — t'-.i;., some large-celled mosses —
directly they are immersed in it. He tried boiling them first
in a little dilute glycerine and water, also adding a little water
to the medium, but without improvement. He would be glad
of suggestions as to the cause of this, or a formula for making
the medium other than that given in Davies' book on " Mount-
ing Microscopic Objects." I do not think I have ever used
this medium myself. Can any reader make any suggestions ?
Naming Specimens.

H. II'. ]'., BiriniiigJiam. — I am anxious to help my readers
as much as possible, but I do not think you quite realise how
much work is involved in naming specimens. Microscopy
covers so wide a field that it is impossible for one man to
have the minute specialized knowledge necessary for identify-
ing specimens in the whole field of Nature, and I have there-
fore to get my friends in Cambridge and elsewhere to assist
me in such matters. For instance, I would rather not name
specimens of either fungi or mosses, and I hesitate to hand
them over to specialists unless I am quite sure that they
are more or less uncommon species which have an unusual
interest to some correspondent who is working specially on
them. If this bo so in your case I will do what I can for you,
but I trust you will forgive this public reference, because I
receive so many requests to name specimens that I have
thought some little explanation may be of service. On purely
microscopical matters I am glad always to do what I can,
however elementary the questions.

Observation of Flagellar and Cilia.

/. If. Broicii, Inveykcithing. — The J-inch objective you
mention is an excellent one, but flagellse and cilia are generally
most difficult to see, especially if the animal is alive. Your
best plan will be to add a little cocaine to the water and watch
till the movement begins to slow down, when you may be
more successful. I do not think a more costly lens would be
of any greater service to you, but you are not giving
either yourself or your objective a fair chance if you have not
got a sub-stage condenser. The improvements in modern
high-power objectives are almost nullified without a con-
denser. Could you not extemporise a ring that would enable
you to use a 2-inch or i-inch objective as a condenser ? You
will find, however, that the absence of an iris diaphragm to
adjust the light is yet another drawback, as cilia will not bear
a large cone, being so lacking in contrast. You cannot get
good dark-ground illumination with lenses of higher aperture
than about •& N.A.,in fact you will probably fiud any objective
higher than a half-inch does not give good annular illumina-
tion. The spot must be proportioned to the aperture of the
objective, the larger the angle (that is, generally, the higher
the power) the bigger must be the spot.

{Communications and enquiries on Microscopical matters are invited,
and should be addressed to F. Shillington Scal:s, "Jersey," St,
Barnabas Road, Cambridge.]

KNOWLEDGE & SCIENTIFIC NEWS.

[Feb., 1905.

The Face of the Sky for February.

By W. Shackleton, F.R..-\.S.
The Sun. — On the ist the Sun rises at 7.41, and sets at
4-47 ; on the 28th he rises at 6.50, and sets at 5.36. The
Sun is after the clock, the equation of time being
appro-ximately 14 mins. throughout the month.

For plotting the positions of spot?, with respect to the
a.xis and equator, the following table may be used : —

Axis inclined from N. Equator N. of

point. Centre of disc.

Date.

Feb. 5
.. 15
.. 25

13° 55' W.

17° 35' w.
20° 40' \v.

6-54'
7° II'

The Moon

—

Date.

Phases.

Feb. 4 •■

,, 12 ..
., 19 ..
.. 26 ..

• New Moon
D First Quarter
0 Full M'oon
i Last Quarter

4
6
10

6 a.m.
20 p.m.
52 pm-

4 a.m.

Feb. 8 ..
„ 20 ..

Apogee
Perigee

7
II

48'p.m.
36 p.m.

A partial eclipse of the Moon takes place on February
19. In this country the Moon rises about half an hour
bsfore first contact with the shadow.

Diagram abowinK Path of Moon IhrouKh the Earth's Shadow.

Further particulars are as follows :
F"irst contact with Penumbra Fel

.. I, „ Shadow

Middle of Eclipse
Last contact with Shadow

„ „ „ Penumbra

Magnitude of Eclipse 0-410 (Moon's i3iarn.

Moon rises at Greenwich, 5.16 p.m.

Occi'LTATioNs. — The following are the occultations of

the brighter stars visible at Green wich at convenient times.

Diwpiwarancc. I Reappearance.

4.41 p.m.
5-54 ..
7-0 ,,
8-7 ,.
919 ..

Angle feom Angle from

' Mean

Time.'

N. Ver- N. Ver-

poinl. lex. point, lex.

IJ..' 9' I Hull .

13..' B.AX:. 1^1

14.. I tir Taun

ai.. n VirRJnitis

p.in. i i

5." rf I'.j

3»

}<4

4-9

e.iS

5-a

6.57

4''>

10.5

pm.

Thi; Planets. — Mercury is a morning star, rising about
an hour before the Sun for a few days early in the month ;
later, he is in too close pro.ximity with the Sun to be
observable.

Venus is now the most brilliant object in the evening
sky, looking S.W. The planet is at greatest elongation
of 46^41' E. on the 14th, setting about y.io p.m. on the
1st and at 10.5 p.m. on the 2Sth. About the middle of
the month the apparent diameter of the planet is 25",
whilst the phase is "half moon," 0-516 of the disc being
illuminated ; her lustre, however, is increasing, as the
point of ma.ximum brilliancy is not attained until near
the end of next month. Throughout the month the
planet souths about 3 p.m. on each day, and is easy to
discern about this time even with the naked eye ; the
meridian altitude increases from 38- on the ist to 51 ' on
the 2Sth. The Moon is near the planet on the evening of
the 8th. being 3 20' S. of \'enus.

Mars does not rise until after midnight.

Jupiter is diminishing somewhat in brightness, and
getting more to the west, and sets about 10.45 P-"^- "6'^''
the middle of the month; he is, however, very conveni-
ently situated for observation in the early evening. The
equatorial diameter of the planet is 37"-3 on the 13th,
whilst the polar diameter is 2"-4 smaller. The satellite
phenomena visible in this country are as follows : —

c
5

P.M.s.

H. M.

P.M.'s.

c
2

1 P.M.'s.
a H. M.

F.h

IVh.

Feb.

II.

Tr. I.

6 50

III

Sh. 1.

6 42

Sh. E. 6 28

II.

Tr. 1:.

9 23

III

Sh. E.

8 28

Tr. I. 8 30

II.

Sh. I.

9 26

Oc. D.

9 22

Sh. I. 9 38

II.

Kc. K.

6 I

Tr. I.

e 31

Ec. R. 9 8

4 1

Tr. I.

10 I

Sh. I.

7 42

Sh. E. 6 J9

s 1

Oc. D.

7 23

Tr. E.

8 44

II.

Oc. D. 9 17

Tr. K.

6 45

Sh. E.

9 55

11.

Sh. I. 6 36

.Sh. K.

7 59

Ec. R.

7 13

11.

Tr. E. 7 2

Tr. I.

9 35

11.

Oc. D.

6 29

11.

Sh. E. 9 5

II.

Kc. R.

8 39

III.

Tr.E.

8 9

'•

Oc. D. 7 52

" Oc. D." denotes the disappearance of the Satellite behind the disc, and
** Oc. R." its re-appearance; *''rr. I." the ingress of a transit across the disc,
and " Tr. E." its egress ; " Sh. I." the ingress of a transit of the shadow across
the disc, and " Sh. E." its egress.

Saturn is no longer observable, being in conjunction
with the Sun on the 12th.

Uranus is unobservable.

Neptune is on the meridian about 8,45 p.m. on the 14th ;
he is describing a short retrograde path in Gemini, and
can be found by reference to the star i^ Geminorum.
Right Ascension. Declination.

Neptune (F"eb. I4). 6'' 24"" 17" . . N. 22" ly' 18"

M Geminorum . . e"* 17"" 13' .. N. 22" 33' 37"

Meteor Showers: —

Date.

U.A.

Near to Characteristics.

Dec.

Feb. 5-10
.. J5
• . 20

75°
Z3<i"
1810

■\- 41^ 1) Aurigx Slow ; bright,
-f 11" a Serpenlis Swift; streaks
4- 34" CorCaroli Swift; bright.

Variable Stars. — Algol maybe observed at minimum
on the 5th at 9.8 p.m., 8th at 5.57 p.m., 25th at 10.51
p.m., and 28th at 7.40 p.m.

o Ceti (Mira) is due at a maximum on 25th February ;
its period, however, is somewhat irregular.

KDomledge & Seieotifie Hems

A MONTHLY JOURNAL OF SCIENCE.

Conducted by MAJOR B. BADEN-POWELL and E. S. GREW, M.A.

Vol. II, No. 3. [new series.]

MARCH, 1905.

C Entered at -]
Stationers' Hall. J

SIXPENCE.

CONTENTS.—See Page VIL

The Coming Totatl
E^clipse.

By W. Shackleton, F.R.A.S.

is apparent on looking into the future to see what oppor-
tunities will be available during another solar cycle for
observations of our fiducial star under these special con-
ditions. Enumerated below are the total eclipses of the
sun during the next eleven years, with the locations of
the shadow paths.

Date

The extreme importance of making exhaustive observa-
tions during the total eclipse of the sun on August 30,
1905, is evident when we review the progress of astro-
physics during the past decade, and bear in mind that
the sun is the only star which can be examined in
geometrical detail, whilst onl)' the integrated effect of
every other star can be studied. The elucidation of
many stellar problems depend almost in their entirety on
a more perfect understanding of the conditions existing
on the sun. To give an example, the star y Cygni presents
a spectrum which, although akin to the Fraunhofer spec-
trum, differs markedly in detail, yet the outlying portions
of the sun give, in the " flash," a spectrum bearing a
close resemblance to that of the star, -\gain, the urgent
need of making every preparation to collect useful data

1907 — Jan. 14
igoS — Jan. 3
igoS — Dec. 23

igog — June 17

1910 — May g

191 1 — April 28
1912 — .April 17

igi2 — Oct. 10
1914— -Aug. 21

igi6 — Feb. 3

Where visible

5
01

Ural Mountains, Central Asia,

China
Pacific Ocean ; ends Isthmus of

Panama
South Atlantic. (Annular eclipse,

forming into a " Total " of

short duration)
Greenland, Arctic Regions, N.

Siberia
Antarctic Ocean, passes over

Tasmania near end of eclipse
Australasia, Pacific Ocean
Spain, (.\nnular eclipse, form-
ing into a "Total" of short

duration)
Venezuela, Brazil, S. Atlantic
Greenland, Norway, Sweden,

Russia, Persia
Pacific, Panama, Colombia,

Venezuela, .Atlantic, Azores

Path of Shadow. Eclipse, 1905, August 30.

KNOWLEDGE & SCIENTIFIC NEWS.

[Mar., 1905.

The total eclipse of the sun during the present year on-
August 30 possesses many advantages, in that it is
almost at our own doors, is of long duration, and the
most accessible for many years to come.

The shadow strikes the earth in Canada south-^yest of
Hudson's Bay, where the eclipse begins at sunrise ; it
then leaves the .\merican Continent near DominD Har-
bour, Labrador, crosses the .-Vtlantic, and reaches Europe
near C. Ortegal, in the N.W. of Spain, traverses over
Spain, near Oviedo, Palencia, Burgos, .\teca, Calatayud,
Castellon, thence across the Mediterranean to Algeria,
Tunis, Tripoli, Egypt (near Assouan), and _ finally to

On account of its proximity, Spain will be largely
favoured as a site for making observations, and, in addi-
tion to parties from this country, further contingents may
be expected from America. Burgos, already visited by
some members of the British Astronomical Association
after the eclipse of 1900, is of easy access, being served by
the direct Paris Madrid rail, and can be reached from
London in 32 hours, whilst Palencia can be reached
almost as quickly, and has the advantage of being
described as " healthy and cold." In consequence of the
meagre accommodation (the greater part of which is
already engaged at Burgos), a prolonged stay is undesir-

Spain, showing Central Eclipse Line, with North and South Limits.

Arabia, where the sun will be eclipsed at sunset. The
width of the shadow varies slightly at different portions
of the track, but it is, approximately, 120 miles.
Further particulars are as follows : —

Local Time.

Sun's
Altitude.

Beginning of
Totality.

Duration.

m. s.

Domino Harbour

(5. II a.m.

2 38

27°

Oviedo

IZ.38 p.m. (noon)

3 40

56°

Paleacia

12.48 p.m.

3 30

,6«

Burgos . .

12-31 p.m.

3 35

56»

Ateca

1-4 p.m.

3 40

56°

Calatayud

1.4 pm

3 40

56°

Castellon

1. 21 p.m.

3 30

55°

Assouan (near

4.36 p.m.

2 33

24"

able, but San Sebastian or Biarritz may serve as a base
for the former, and Santander for the latter place.

Oviedo can be reached from Palencia in about 7A hours,
and is one of the few places m Spain witli hotels
described i\s " good."

Ateca and Calatayud are more difTicult of access, as a
journey to Madrid or Saragossa is involved, thence by
the Madrid and Saragossa line.

The disadvantage of the Mediterranean coast is the
great heat at this period of the year, but more favourable
weather conditions are to be expected the further east-
wards one proceeds. Castellon is one of the most pro-
mising places and can be reached from Valencia in less
than two hours, or from Barcelona in six hours, whilst
the journey from London to Barcelona can be made in
thirty hours, or quicker than to Madrid.

A skeleton itinerary, with times of trains now in

Mar., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

operation to some of the above places, will give some
indication of the time one should allow.

Burgos and Palenci
London, 2.20 p m.
Paris, 10.7 p.m.
Paris, 10.36 p.m.
Burgos, 9.33 p.m.
V'enta de

Banos, 11. 15 p.m.
Venta de

Banos, 1.46 a.m.
Palencia, 2.1 a.m.
Santander, —
London to Barcelona
{via Lyons^

h. m.
3t 46

29 J hrs.

Atf.ca ani> Calatavud

London, 90 p.m.

5 50 a.m. 1

12 iS p.m

2.25 p.m.

2.50 p.m.

Paris
Paris,
Madrid
Madrid

h. m.

5G 50

Ateca,

4.20 a.m.

Calatayud, 4.50 a.m.
Saragossa, —

Barcelona to Castellon
(viii Tarragona)

6J hrs.

The work to be attempted at any of the stations named
has to be done in about 3^^ minutes, hence to obtain
useful results one should have a knowledge of some of
the problems requiring further investigation or of new
points to be attacked and arrange a programme
accordingly.

The aim of all eclipse expeditions is to study those
parts of the sun which are visible only during a total
eclipse, in order to .gain a further insight into the physical
condition of the sun as a whole, and ultimately to bring
this knowledge to bear on other cosmical bodies in
general. The most obvious feature of a total eclipse is,
of course, the Corona, and although it has been so re-
peatedly assailed, deeper and more perplexing problems
have arisen in proportion to the assaults, and Professor
Campbell concludes that " it is as enigmatical as ever."

Some of the more interesting points regarding the
Corona are : —

Its visibility, photographically or visually, in the partial
phases of the eclipse.

The extension of the coronal rays.

The differentiation of the part which shines mostly by
reflected light from that which is self-luminous.

Its spectrum.

Other points, such as its connection with prominences,
dark rifts, detailed structure, photometric value at vary-
ing distances from the Moon, rotation, brightness and
wave lengths of its spectrum lines, cannot be fully con-
sidered in an article of this length.

Small cameras can with ad\'antagebe employed in the
solution of the first three points, but to meet with any
measure of success the lens ratio of aperture to focal
length requires to be large, partly in order that the ex-
posure may be short enough to neglect equatorial follow-
ing which will be unprovided for in the majority of cases
with this class of instrument.

The most notable result as to coronal extension is the
photograph obtained by Mrs. Maunder at the eclipse of
1898, with a lens ratio of /'6 exposing 20 seconds on a
triple-coated Sandell plate, but as the conditions of the
coming eclipse are different and the sun is approaching
a maximum, long rays may not exist, or if present be no
brighter than the sky background. However, it is in this
direction that one must look for the recording of rays to
the extent that the naked eye is able to perceive them.
For prominences and the recording of detail of the
lower parts of the Corona, a lens of long focal length,
slow plates, and exposures of half a second or less are
preferable, but as the scale of ordinary cameras is small,
such records are best obtained with larger instruments,
as the every-day camera is more profitably employed on
other work.

Photographs should be taken several ininutes before
and after totality to ascertain when the Moon's limb can
be discerned beyond the arc shown on the solar disc ;
when this point arrives it is evident we are seeing the
Moon projected on the Corona as a background. It
would be desirable to prevent the direct image of the

crescent sun falling on the plate, but as this is varying, it
is scarcely possible, except with a large image and clock
movement, though one might try the effect of a screen
such as is used in cloud photography, one of a greenish
hue being preferable.

Such photographs will furnish useful data to determine
the feasibility of observations of the Corona in annular
eclipses or even without an eclipse.

In consequence of the varying brightness of the Corona
at different distances from the sun's centre, it has usually
been found necessary to compile a composite picture
from many negatives to exhibit the detail of the coronal
extensions from the sun's limb to their extremities, since
any one exposure will only be correct for a particular
brightness, some parts being over and others under-
exposed. Now, the type of Corona to be expected is
that usually shown at the maximum sun-spot period, and
will in all probability be similar to those of 1882 and

1893; Professor Turner has shown that in the case of
the latter the law of luminosity of the Corona was :
. , varies / distance from \~(>

Brightness ^^ (^ sun's m,t re )

He has shown also that the same law represents the
luminosity of the 1898 Corona, and probably it ap-
proaches near the truth for all the various types of
Coronas, and is more satisfactory than that formulated by
Professor Harkness in 1878, who gave the brightnesf
varying simply as the inverse square from the hmh, for
if the Corona be largely made up of minute particles,
other inverse powers of the distance in addition to the
ordinary inverse square law of luminosity will enter into
the equation.

Hence to obtam photographs of the Corona with the
exposure correct for every part, it will be necessary to
adopt a method similar to that employed by Buckhalter,
and use a rotatmg disc immediately in front of the plate
on which the image falls, with a templet cut out to give
the exposure in accordance with the above law.
(To he Continued.)

Exhibition of Meteorological Instr\iments.

The Council of the Royal Meteorological Society have
arranged to hold, by permission of the President and Council
of the Institution of Civil Engineers, at their house in Great
George Street, Westminster, an exhibition of meteorological
instruments from March 14 to 17 next. The exhibition vvill
be chiefly devoted to recording instruments; but will also
include new meteorological apparatus invented or first con-
structed since the Societv's last exhibition, as well as photo-
graphs, drawings, and other objects possessing meteorological
interest, or instruments of very early origin.

KNOWLEDGE & SCIENTIFIC NEWS.

[Mar., 1905.

R^are Living AniirriaLls
in London.

By P. L. ScLATER, D.Sc, F.R.S.

IV. — The Glossy Ibis.

That the "Glossy Ibis," formerly kimun to the gunners
of the H.-istern counties as the " Blnck Curlew," was
much more abundant in the fens of Norfolk and Cam-
bridjjeshire in past years is certain, but whether it was
ever a regular breeding inhabitant of those districts
does not seem to have been clearly made out. In these

easy, and secure from man's intrusion. In 1883 this
district was visited by Mr. W. Ivagle Clarke and a
party of Ornithologists, who subsequently published an
excellent account of their excursion in " The Ibis." In
a breeding station on the Save they found an enormous
colony of Herons of different species. Pigmy
Cormorants, Spoonbills, and Glossy Ibises engaged in
making their nests in the bushes amongst the reeds,
and forming a most attractive spectacle. Similar ac-
counts are given bv those who have visited the breeding
haunts of this bird on the (niadalc|ui\ir, in Southern
Spain, in the more sequestered lakes of India and
Ceylon, and even as far off as in Eastern Australia,
where, as w'e are informed bv Mr. A. J. Campbell, in

The Qlossy Ibis.

days, however, the Glnssy Ibis can only be classed as a
not very infrequent straggler to the British Islands,
mostly occurring in the eastern and southern counties.
But it is a bird of wide range, being found in suitable
localities all over Africa, Southern Asia, the Moluccas,
and as far off as F.asfern Australia, where it has lately
been a.scertaincd to nest more or less frequently.

In Europe the principal strongholds of the Glossy Ibis
arc in the marshes of the I.owCr Danube, and the
swamps of the Guadalquivir, in Southern Spain, in both
of which Ifirnlities it breeds in large communities in
company with other water-birds. In the former
district, near Belgrade, and extending into the
vallevs of the Theiss and I he Save is an end-
less plain, covered with forests of reeds, which
is a perfect paradise for fish-eating birds of
all sorts. It is full of rivers and lakes, flooded
meadows, and half-submerged forests of willows and
alders, a combination well calculated to make bird-life

his volume on the " Nests and Eggs of Australian
Birds," the Glossy Ibis was first detected breeding in
18S9. This Ibis is also found in the southern States of
North America, but in .South .America it appears to be
replaced by a closely-allied form, the While-faced Ibis,
distinguished by a narrow white line on I he front of
the beak.

In the Zoological .Society's Gardens the (ilossy ll)is
was formerly f|uite a rare bird, the first record of its
presence there having been made in 1866. But in
Januarv, 1893, the Society purchased from a
dealer seven young specimens of the closely-allied
White-faced Ibis imported from Argentina, which at
that time could not be distinguished from examples of
the Glossy Ibis of the same age. These were placed in
the Great Aviary, where they did well. In August of
the same year they were joined by twelve specimens of
the European Glossy Ibis, presented by the late Lord
l.ilford, who had received them along with other water-

Mar., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

birds from his correspondents at Seville. The South
American and European cousins made friends at once,
and formed a united flock, amongst which it was hardly
possible to discriminate the two species, so much alike
are they except in the height of the breeding season.

In the spring of 1895 the Ibises showed signs of
breeding, and were to be seen carrying about sticks in
their beaks. Many pairs were soon formed, without
regard as to both sexes belonging to the same variety.
The nests were placed on the summits of the stunted
trees in the Great Aviary, formed of sticks, straw, moss,
and other materials supplied to the birds bv the keepers.
The first brood of three young ones was hatched on
June 19th of that year. Since that period the same
process has been repeated every season, and though
there have been many accidents and misadventures to
these birds, which have a difficult task to hold their
own amongst so many evilly-disposed neighbours, the
flock of Glossy Ibises still exists, and the birds go on
breeding, with more or less success, every year. It is
impossible to tell the exact parentage of the different
birds now in the Society's Gardens, but the greater
number of them are probably hybrids between Plegadis
falcinellus of Europe and P. guarauna of Argentina.

A new consignment of the European species has
lately arrived, which, when the breeding-season of 1905
comes on, will, no doubt, give fresh vigour to this
most interesting family.

Heredity.

By J. C. Shenstone, F.L.S.

II.
Sprengel, in his great work, led to the knowledge
that forms of flowers exist solely for the purpose of
securing the fertilisation of the seed. Those flowers
which are inconspicuous and do not attract insects
by their perfume or by their honey, as for instance
most of the grasses, discharge clouds of pollen into
the air, which is conveyed by the wind to other plants;
but in the majority of cases flowers are specially con-
structed to attract insects in search of honey and of
this pollen, as the yellow dust is now called. In their
search they convey portions of the pollen from flower
to flower, and thus the seeds of one plant are usually
fertilised by pollen conveyed from another. Sprengel
did not realise the full importance of the cross-fertilis-
ation thus secured, but no botanist now doubts that
cross-fertilisation is a profound necessity, and that
the innumerable forms of flowers and their brilliant
colours are due to their being constructed to attract
the attention of insects. Sprengel, like many other
great men, was born too soon.

Darwin's great work in establishing the theory of
Evolution, and in demonstrating that we owe the in-
numerable forms of animal and vegetable life to a
process of development, and to a process of " natural
selection " — those individuals least suited to their en-
vironment disappearing as the result of the fierce com-
petition constantly proceeding in nature — is too well
known to need repetition here, but I should explain
that whilst Chas. Darwin was elaborating his theory,
and immediately afterwards, a mass of work was
done by others which contributed to place the new
development of knowledge upon a sure foundation.
Not least among those who helped in this work was

Nageli, who attacked the problems of life from quite
a different direction, bringing a considerable training
in physical enquiry to bear upon the study of the
development of plants by the aid of the microscope.

If a very thin slice of the pith from a young shoot
of, elder be examined under the microscope, it will be
seen to consist of a number of small bladders known
to botanists as cells. When a cell is subjected to a
temperature of 122 F. its contents shrink away from
the outer skin, and can be discovered to consist mainly
of a viscid granular substance. Nageli showed that
this was true of the cells of the most lowly as well as
the most highly developed plant and animal, for both
of these are entirely composed of such bodies, and that
everything living has grown from a single cell by a
process of division, each cell becoming divided into two
or more perfect cells, which are seen to divide again and
again during the life of the tissue. Nageli also en-
riched the theory of evolution, as afterwards acknow-
ledged by Chas. Darwin, by establishing the fact that
there exist laws of variation in living things, which
lead to their perfection, and also to their variation
independently of the changes brought about by the
struggle for existence. Thus at the end of the last
century it was admitted that the essential basis of
animal and vegetable life lies in the granular sub-
stance contained within the cell; that each animal
and each plant is developed from a single cell now
called the germ-cell\ and that whilst the chemical and
physical forces acting in living things are indistin-
guishable from the same forces when acting in dead
matter, there exist indications of yet other laws of
variation which lead to the perfection of living forms
and to their difl'erentiation. Finally, that the innumer-
able forms of plants and animals existing to-day are
the outcome of natural selection; that these are due
to the survival of those most suited to the changing
conditions of life, and to the destruction of forms less
able to hold their own in the struggle for existence.*

We are all familiar with the stages through which
some members of the animal kingdom, e.g., butter-
flics and moths, pa.ss during their development into
the perfect form, k caterpillar is hatched from an
&iCZ^ this in due course is transformed into a chrysalis,
from which the perfect butterfly or moth emerges, and
the frog passes tlirough the tadpole stage before ar-
riving at complete development. Some classes of
plants pass through similar .stages, and it is held by
most naturalists that the history of each individual
recapitulates the history of its ancestry, and that if
we traced the development of an animal or a plant
from a single cell, or minute viscid bodv from which
each individual is developed, we should discover the
leading features of its ancestry.

After Darwin's theory had .secured the support^ of
men of .science, Weismann impressed upon us the im-
portance of the fact that all the characters, including
the most minute peculiarity of bodily structure or
mental disposition, must be transmitted from genera-

•It is contended by some botanists that species may liave come
into existence suddenly. The variations in both plants and
animals, popularly known as sports, are known to all observers 01
nature. The varieity of clover with four leaflets instead of three,
and human beings with an abnormal number °« fin-ers or toes
serve as examples. It is contended that such variations, called by
biologis's mutations or discontinuous variations, may have given
rise tS new species. Gardeners and breeders o f an.nials h aye taken
advantage of such variations for producing cultivated va^eties, but
no variety obtained in this manner has so far proved capable ot
holding its own in its wild state.

KNOWLEDGE & SCIENTIFIC NEWS.

[Mar., 1905.

tion to generation through the viscid contents of the
g-erm-cells. Not only has this minute body concen-
trated within it the power of reproducing: ail the
anatomical details, but it must also transmit the pecu-
liar difference of temperament of animals, which has
g'iven to the cat and dog, for example, a disposition to
scratch and bite one another from time immemorable.
This conception of the g-crm-cell would lead us to re-
gard all animal and vegetable life as, in a sense, im-
mortal; for as every living thing contains within it the
power of producing this germ-cell, which in its turn
has the power of developing all the mental and ana-
tomical characters of the individual from which it is
derived, it may be argued that each living thing con-
tains within it the possibility of immortality.

The next contribution to our modern views upon
heredity was made by Francis Galton. It is clear
that animals and plants all receive contributions to-
wards the characters they inherit, not onlv from their
two parents, but also from their four grand-parents,
their eight great-grand-parents, and in fact any an-
cestor may contribute characters down through a long
line of descendants, and hence that each individual
living thing must have inherited its characters from
many millions of ancestors. As the number of ances-
tors becomes doubled in each generation through
which we carry our enquiry, a simple calculation will
demonstrate the large number of ancestors from which
the individual has descended. In ten generations the
number exceeds two thousand, provided that there
has been no inter-marrying, and these figures increase
more rapidly the further back we carry our calcula-
tions. It is obvious that only a portion of any individual
ancestor could be transmitted. Thus if one parent has
dark hair and the other flaxen hair, the child could
not have both flaxen hair and dark hair; he must in-
herit either flaxen hair from one parent or dark hair
frorn the other parent, or he must inherit an inter-
mediate shade, receiving contributions from both
parents. Tlie child of a very tall father and a very short
mother will either be tall, short, or of some inter-
mediate heig-ht; he could not po.ssibly inherit the
characters of both parents in this respect. When we
realise the vast number of ancestors from each of
whom individuals may inherit characters, of those
contributed by all the rest, we see how complicated
the subject of heredity becomes. Rut the actual con-
tributions from ancestors seem to diminish as we go
backwards, for the contributions of the two parents,
one would .suppose, must equal those of the four grand-
parents, of the eight grcat-grand-parents, and so on,
since all the contributions combine into one individual.
It is therefore convenient to confine the enquiry to the
few later generations from which most of the charac-
ters have been received. Galton has endeavoured to
do this and to construct a law of heredity upon these
con.siderations. For this purpose he supposes that
each individual receives half his characters from his
two parents, one quarter from his four grand-parents,
and one-eighth from his more remote ancestors. This
assumption has received some support from materials
found in the stock of the Basset hounds, started some
years previously by .Sir Everett Millais.

Gallon's hypothesis refers more particularly to those
characters which blend in the offspring. ITierc are
however, many characters which will not blend. The
coat colour of horses affords a good example of these.
One seldom sees horses whose coat colour cannot be
referred to one of the colours known as bay, chest-

nut, grey, and so on; the eye colour in man affords
another example; we see brown eyes, blue eves, hazel
eyes, etc., but we seldom see tints which cannot at
once be referred to some one or other well defined
tints. When the eye colour of the two parents dif-
fers in tint, the child is stated to inherit this charac-
ter from one p;u-ent only, or from some one more re-
mote ancestor. A remarkable scries of experiments,
published in 1865, by Gregor iMendel, dealing more
particularly with these characters which do not blend
in the offspring, have lately been the subject of much
animated discussion.

(iregor Joliann Mendel, born in Odran, in .(Vustrian
Silesia, was the son of well-to-do jicasants. In 1847
he was ordained priest, he studied physics and natural
science in Vienna, and returning to the cloister be-
came a teacher in the realschule at Brun. The im-
portance of his experiments, which were carried out
in the garden of his convent, were quite overlooked
until recently, when they were simultaneously redis-
covered by several investigators. The circumstances
connected with Mendel's researches appear to be
peculiarly like those of Sprengel's discovery of the
fertilisation of plants by the aid of insects, except
that, fortunately, Mendel docs not appear to have al-
lowed his enthusiasm for science to interfere with his
duties to his Church. Professor de \'rics called at-
tention to Mendel's remarkable memoir in 1890, and
Mendel's observations have since been confirmed by
other workers.

Tliese investigations consisted in experiments made
by crossing varieties of plants differing from one
another in some important pair of characters, and re-
sulted in progeny being obtained which inherited those
characters according to fixed numerical rules; thus
Mendel's experiments give us ground for hoping to
discover the laws which control the forces of heredity.
He made a large number of experiments on the garden
peas, selecting varieties having pairs of characters
suited to his purpose. If the reader will observe the
seed-peas sold at seed-shops, he will notice that some
are almost round with smooth coats, whilst others
•are very much wrinkled; he will also discover, unon
splitting these seed-peas open, that the substance of
some of them is decidedly green in colour, whilst
in others it is bright-yellow. If he carries his enquiries
further and grows plants from these seeds, he will
find that some produce very inflated pods, whilst
others produce pods which do not exhibit this charac-
ter. It was because the common pea lent itself to
Mendel's purpose, by affording many such pairs of
characters, that he experimented upon it. Ilis results
were, in brief, after crossing many plants dilTcriiig in
some one pair of characters, in every case all the off-
spring could be referred to one or the other of the
parent forms. This character to which the offspring
'of the first cross could be referred, he called the domi-
nant character, and that which disappeared he called
the recessive character. From the seed obtained
from a first experiment he made a second, when he
found that only twenty-five per cent, of the offspring
from this second cross retained the dominant charac-
ter; the remaining sevcnty-fi\c per cent, having re-
verted to the recessive character; but he also found
that the offspring which remained dominant in this
' econd experiment continued dominant in all subse-
qucnt generations. Carrying his experiments a stage
further with the seventy-five per cent., which had re-
verted to the recessive character, he found that one-

Mar., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

third of these remained recessive in all subsequent genera-
tions. And still continuing- his experiments with the
remaining^ fifty per cent., he found they g^ave recessive
and dominant characters in the same proportions as
in earlier generations.

In recent years many sets of experiments have been
made to test Mendel's results, and Mr. W. Bateson
has initiated a movement for the thorougfh further
investigation of the subject experimentally, whilst, on
the other hand, a school of biologists led by Professor
W'eldon, who have been applying the mathematical
methods for solving the difficult problems of heredity,
contend that the results obtained by Mendel do not
accord with the mathematical laws as worked out h\
those following the lines of enquiry laid down by Gal-
ton. These differences in the results obtained by the
two schools of biologists are giving rise to much con-
troversy, but the history of science is rich in instances
in which investigations giving apparently discordant
results have led up to import-ant additions to our
knowledge. We have very good ground for hoping
that, in the near future, very important further steps
may be made in this direction for placing our know-
ledge of this important subject upon a scientific basis.
A problem of great interest which has provoked
much discussion in recent years, is the question
whether characters which have been acquired during
the life of an individual are transmitted to its off-
spring. Darwin under the title of " Use and Disease,"
admits it as possible that the power of flight possessed
by wild ducks may have been lost by tame ducks in
consequence of disuse. In more recent years, Weis-
mann has convinced himself that characters of this
nature are not transmitted to the offspring. The
blacksmith's arms become abnormally developed in the
exercise of his calling; but no instance has been re-
corded in which blacksmiths' children were endowed
with any special development of the muscles of their
arms. The feet of Chinese women have been artifici-
ally distorted for ages, but they will still develop to
natural proportions if permitted to do so. The loss
of power of flight by tame ducks is best explained by
the survival of those varieties with small powers of
flight, under artificial conditions, being favoured by
selection, whilst in the wild state the birds with great
power of flight can best escape from their enemies.
There is, however, another description of acquired
character, which cannot be finally dismissed without
further investigation. Some keepers and others ex-
perienced in training dogs for sport are convinced
that the offspring of dogs which have been trained
can invariablv be broken in with much less trouble
than the offspring of dogs from equally good stock
which had been kept as domestic pets. A naturalist
friend of mine who has kept various species of mice
in confinement, assures me that whilst the progeny
of white mice, whose ancestors have been kept for
many generations as pets, in their earliest stage of
growth show little fear of man — though we have no
evidence of this characteristic having been favoured by
selection — the offspring of the field-mouse, as soon as
it can run, will scamper off on the approach of man.
It is difficult to explain the peculiar habits of the
cuckoo, unless they were acquired at some early
period. The solitary wasp, which, like the cuckoo,
never knows its parents, constructs a nest or cell in
which it stores small caterpillars, injured but not
killed, and hangs its eggs well out of risk of damage
by the caterpillars, so that when the e§^ hatches the
grub may find a plentiful store of fresh meat at hand.

Many similar examples occur amongst fishes and in-
sects. And until we can satisfy ourselves that these
animals, fishes, and insects have sonic means of com-
municating with one another in mature life, or until
it has been shown how such habits can arise without
having been acquired, it is difficult to dismiss al-
together the inheritance of acquired characters as im-
possible. Professor Herring, in an address upon
heredity, delivered at the Imperial Academy of
Sciences, Vienna, May 30th, 1870, suggested that as
it is noteworthy that every act of our daily lives is due
to unconscious memory, the power of memory may be
the property of all organised matter, and that it may be
tiansmitted from one generation to another through
the germ-cell. This problem should not be beyond the
reach of experiment, and if established might not only
explain these obscure phenomena, but many others,
both in the vegetable and animal kingdom : the
power possessed by roots of penetrating the soil, avoid-
ing light and air; the habit of some flowers of poking
their seed-vessels into crevices in rocks and walls or
burying them in the ground; the habit of sun-dews of
closing their glandular hairs when stimulated by insect
prey; periodicity, so frequent in animals and plants, as,
for instance, the opening of those flowers which require
day-flying insects to convey their pollen from plant to
plant in the morning, whilst those flowers which rely
upon night-flying insects for this duty open in the even-
ing; and many other similar phenomena. The possi-
bility that the transmission of the power of memory
from one generation to another may play some part in
transmitting such habits should not be entirely dis-
missed until it has been tested by careful experimental
investigation.

Other phenomena of heredity not having advanced
since the pre-Darwinian days, we must proceed to con-
sider the possible application of a greater knowledge
of the subject to the benefit of mankind. Tlie appli-
cation of well-established rules by the breeder of ani-
mals and by horticulturists is too obvious to dwell
upon. Already racing and draught horses, fat cattle,
sporting dogs, brilliant flowers, luscious fruit, and
other things demanded by men are attained by the
practical man almost to order; nevertheless, an exact
knowledge of the laws underlying these industries
might bring about as great a revolution as that which
has been accomplished in fields of activity by the ap-
plication of principles of physical science. But a
question of even greater importance remains. What
eft'ect will a more exact knowledge of these laws have
upon the human race itself?

Xt a recent meeting of the Sociological Society,
allusions were made to the " false social standard "
and to the indiscriminate attachments by men and
women. It was suggested that a wider diffusion of
a knowledge of the laws of heredity "would bring in-
fluence to bear upon marriages." Sound knowledge
of the scientific laws underlying the phenomena of
nature has had a most beneficent effect upon
humanity in the past, and any addition to our know-
ledge will undoubtedly be valuable in the future, yet
the sober student must find some difficulty in fore-
telling the direct effect of an extension of our know-
ledge of heredity upon the races of men. It is diffi-
cult to conceive by what system of exact measure-
ments we could estimate the subtle and innumerable
physical and mental traits which go to the making of
a Napoleon, a Bismarck, or a Darwin.

Sir Edwin Arnold foretold the destiny of the
Japanese race, at a time when they were ree-arded by

KNOWLEDGE & SCIENTIFIC NEWS.

[Mar., 1905.

Western people as a nation of intelligrent and artistic
children; but I fail to see how a scientific knowledge
would enable us to derive accurate and numerical value
from the subtle and remarkable qualities which have
enabled Japan in a few years to raise itself to the
level of a great Western nation, nor how we could
set about the business of producing such a race.
Without some quantitative method of measuring all
the qualities which make the higher type of man, the
direct application of scientific methods would be im-
possible.

Creation of Species.

To THE Editors of " Ksoulkdge."

Dear Sirs, — In Mr. Shenstone's interestin;: article on
Heredity, on p. 17. he writes :—" The belief that every form
of animal plant owes its existence to a special act of creation
and . . . accorded with the tenets of the Churches."

The last few words are somewhat vague, but the only theo-
logical dogmas bearing on the subject are those held by the
opposing schools of Traducianism and Creationism. The
latter, it is true, held that ever>' soul (i.^., every separate life
above that of the vegetable world) is separately created ; this
is, however, by no means inconsistent with any theory of
heredity on evolution. While the more widely held theory of
Traducianism— that every life is derived from another lite—
naturally leads to some form of evolution, and would cover the
most violent deductions therefrom.

The writer's further allusions show that he is referring to
popular prejudice or superstition; but it is hardly possible to
style this the " tenets of the Churches."

Yours very faithfully,

Verwood, Dorset, January 14, 1905. Herbert Drake.

^^^^^^

Lighthouse Illumination.

HEi.inoi.AND Lir.iiTHOLSE carries one of the greatest
searchlights actually in use, and its candle power is
placed at the rather incomprehensible figure of
30,000,000. Such a figure conveys very little, but the
Schuckert Company of Nuremburg, which built the
light, have constructed a still larger one, for which
they claim an illuminating capacity equal to
316,000,000 candles. If it were possible to set this
giant on a tower three hundred feet high its rays could
easily be detected 80 miles away, and those who
cherish fancies about light telephony can even imagine
that conversations could be made audible by it at such
distances. The searchlight has a diameter of
6 ft. 6 ins., which would be a large size for a church
clock, and it is built with an iris shutter, such as some
modern cameras have. The leaves of the shutter slide
within a fixed diaphragm in the axis of the ray of light,
and the electrical control is such as to enable the shutter
to govern the movement of the beam of light in hori-
zontal or vertical directions. By the side of these the
flash light lately installed at St. Catharine's Point
seems but an insignificant beacon, for it is only of
15,000,000 candle power. But it is five times as
powerful as the light it replaces, and it is believed that
in clear weather its flicker will be perceptible from the
French coast. The lens has been made in Birming-
ham. The revrjhing portion of the mechanism, instead
of being mounted on rollers as hitherto, floats in a big
trough of mercury, and rotation is easily and accurately
brought about by a clockwork mt-chanism of a kind not
unlike that in old eight-day cincks. The electrical
energy of the light is derived from the same magneto-
electric generators which ha\e been working for 17
vears now without a breakdown.

Why "Common"?

By F. G. Afi.alo, F.R.G.S., F.Z.S.

The careless use of the word "common" is apparent
in our every-day language. To take a familiar instance,
we call " common sense " that which is about the rarest
kind of sense known. The strongest objection, however,
to which the word lays itself open is in zoological nomen-
clature, in which it is in constant use as a trivial specific
distinction: thus Common Seal, Common Gull, (."v:c.

The two Latin equivalents, lomminiis, vulgaris, are, if
anything, yet more reprehensible, not only by reason of
their greater scientific weight, but because their cos-
mopolitan currency tends to aggravate a geographical
fallacy that will presently be indicated. 1 am not Latin
scholar enough to differentiate the shades of meaning
between the two in their zoological application to certain
species of animals. In another meaning, the sensiim coin-
tnitnem of Phaedrus, or the nilgaiis saisKS of Cicero, the
nuances are obvious, and can be respectively rendered, I
imagine, by common sense and the feelings common to
humanity. But as zoological terms I shall, subject to
correction, regard them as identical, and therefore open
to the same criticisms.

It is proposed, for the sake of brevity, to draw
examples that illustrate the drawbacks of these terms
from British vertebrate forms only; it will be easy for
anyone wishing to do so to extend the inquiry to both
invertebrate and exotic species.

Let us have done with the two Latin equivalents first.
As regards British vertebrates, communis is, in the
majority of systems, used of only four forms: Coturnix,
Gnis, Plioccena, and Turtur. As regards G;ks, which, how-
ever common it may once have been in these islands,
cannot by any stretch of the imagination be so described
at the present day, it is true that Mr. Harting has
adopted cinerea as a more satisfactory specific name for a
bird rarely seen hereto-day outside of menageries, though
it bred freely a couple of centuries ago. Yet it is a pity
that he should not also have found an equally satisfactory
substitute in the case of Coturnix, for quails are nowa-
days so rare, thanks in great measure to wasteful
slaughter on the Mediterranean littoral, that every occur-
rence is considered worth recording in sporting and
ornithological journals. As to the turtle-dove, it would
be interesting to know in what part of the country it
can accurately be indicated as common. The marine
mammal, the fourth of these, will be dealt with later.

The other Latin specific prefix is in much more general
use, and nearly thirty British vertebrate forms, or
approximately two-thirds, are fishes. The full list of
British beasts, birds, amphibians, and fishes distinguished
in many writers as vulgaris are as follow: — Mammals:
Sorex, Lutra, Musiela, Sciurus. Birds: Sturnus, Vanellus.
Amphil)ian : Molge. Fishes: Acanthias, Anguilla, Barbus,
Belone, Box, Conger, Dentex, Galeus, Ilippoglossus, Leuciscus,
Liparis, Lola, Mcrluccius, Molva, Mustelus, Pagrus, Solea,
Thymallus, Tinea,

The use of the word vulgaris in respect of types like
the otter, squirrel, starling, or lapwing, which are the
only speciesof their genus known in these islands, cannot
be reasonably objected to like the similar use of the
Lnglish equivalent "common," for the Latin designation
is used in all countries subscribing to what we may term
the international scientific union, and is tiiere admis-
sible so long as this particular species is, generally speak-
ing, commoner than the rest. Of the lapwing, it is to be
observed that Mr. Harting and most modern authorities

Mar., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

substitute criitatus, a far better distinction based on a
familiar character of the bird. Although, as has been
said, our criticism must not be strained in respect of the
cosmopolitan vulgaris, it may be permissible to point
out that the objection would, so far as only British seas
are concerned, equally apply to all but four of the twenty-
nine fishes. Leuciscus, Liparis, Piigrus, and Solea alone
have more than one British species, and of these it is
doubtful whether the dace is more abundant over any
considerable region than the roach or minnow, while the
sole — also known to naturalists, though not to those who
sell and buy fish, as the "common" sole — is not only
yearly growing rarer from the operations of the trawler,
but is practically absent from the more northern waters
of Europe, being replaced on the Scotch coast by the
very inferior lemon-sole (S. lascaris). Professor Mcintosh
once attempted to acclimatise the true sole on the east
coast of that country, but with what success is not accu-
rately determined.

Leaving, however, these two Latin terms as the lesser
offenders in one respect, though often the more serious
in another, I revert to the use of " common," the /o«s et
origo of my discontent. By a number of eminent writers
it is used of the following British vertebrates : —

Reptiles

Mammals.

Birds.

and
Amphibians.

Fishes.

fMoIe.

Wren.

Lizard.

•Sole.

Shrew.

Bunting.

•Snake

•Skate.

tFox.

fCuckoo.

((■ <■., Ringed

tBadger.

tSwift.

Snake).

t Weasel.

•Buzzard.

fViper.

•Seal.

Heron.

Frog.

Rorqual.

tSandgrouse.

Toad.

•Dolphin.

Sheldrake.

Newt.

Mouse.

Snipe.

t Dormouse.

Sandpiper.

•Hare.

Redshank.
•Gull.
Skua.
Tern.

Inaccurate.

t Superfluous

Where not absolutely inaccurate, the use of " common "
is in many cases so clearly superfluous that its mere
suppression with no substitute would answer the pur-
pose. By superfluous, I mean that, as in the case of
several of the fishes previously indicated as specifically
termed " vulgaris," no other animal of the name occurs
within the British region. Five of the mammals, with
the sandgrouse among birds and the viper among rep-
tiles, come under this head. In the case of the cuckoo
and swift, the others of the same name are such rare
stragglers that it is hardly worth distinguishing our
familiar forms as "common." Only a little more than
thirty occurrences (in two cases " several ') of the alpine
swift and three of the needle-tailed species are admitted
in the last edition of Harting's "Handbook" (igoi),
while of the three rare cuckoos that have visited us the
same reliable authority gives twelve records of one, three
of another, and one only of the third. Surely, then, to
write of the common cuckoo or the common swift is a
waste of si.x letters.

The objections, apart from this one of specific isola-
tion, to the use of " common " are two. The word, taken
in its everyday significance, makes no allowance for
gradual approach to e.xtermination. This is perhaps the
more serious blemish of the tw'o. Thus, it is ridiculous

to write today of the buzzard {Biileo vulgaris) as common
anywhere in these islands. The zeal of keepers and the
greed of pothunters have conspired to reduce the remnant
of this handsome bird to almost that irreducible minimum
that immediately precedes virtual extinction. Though
the hare cannot be admitted to the same category, yet
without doubt the operation of the Ground Game Act
has in many districts at any rate all but eliminated it
from the fauna. But the hare comes under the second
objection by reason of its absence from the northern-
most portions of Scotland and Ireland, where it is re-
placed by the blue form. It is, therefore, inaccurate to
retain a specific designation, applicable to the whole
kingdom, which ignores the predominance — if not, in-
deed, exclusive occurrence — of a vicarious form over
considerable tracts.

This second objection applies in the case of the so-
called Common Seal, Dolphin, Gull, Snake, Sole, and Skate.
Correct as it may be to regard these several forms as the
prevalent species in some parts of the territories or seas,
or at certain seasons of the year, strong exception must
be taken to such arbitrary distinction as of general appli-
cation in point of both place and season. As regards,
for instance, the Common Seal {Plicia vituUna), apart from
the increasing rarity and secretiveness of our British
seals, this species is by no means so common in the
Scilly Islands and on the Cornish coast generally as the
Grey Sea.\ {Halicliarns grypiis). This is pointed out by
Mr. Millais in the opening \olume of his splendid work
on our mammals, and incidentally he gives much other
information on the distribution of our various seals. Nor
is the Common Gull (Lams canns) by any means so
familiar at most of our seaside resorts, at any rate in
summer, as either the Kittiwake (Rissa tridactyla) or
Herring Gull (Lanis argentatus), to the latter of which
the term "common" mi^ht be applied with far less
ground of complaint. The objection to applying the
term " common " to the ringed snake is its danger rather
than any error of fact, though the greater abundance of
the viper [Pclias) over most of the island renders the use
of the word in respect of the ringed snake {Tropidonotiis)
inaccurate as well as tending to inspire misplaced confi-
dence in the more plentiful venomous serpent. With
regard to the sole, something has already been said, and
the Common Skate {Haia halis) is certainly less common
on some parts of the coast than the Thornback \R.
clavata) and elsewhere than the Homelyn {R. maculata).

It would be easy to extend the application of these ob-
jections, but sufficient has perhaps been said in support
of a plea for revision of a term unsatisfactory on more
grounds than one. Not all the objections which have
been raised against any and every proposal for renaming
animals, in view of priority or otherwise, can be regarded
as having the same force as that which contends that the
criticised term is absolutely inaccurate.

Electrical Teaching Model.

A NEW piece of apparatus has just been brought out by the
West London Scientific .A.pparatus Co. for demonstrating and
explaining in a simple way the various actions in the electric
circuit. It consists of a series of glass tubes, through which
coloured water is driven by a small centrifugal pump. By
this means, current strength, electromotive force, internal and
external resistance, and fall in potential down a conductor,
may be clearly illustrated.

KNOWLEDGE & SCIENTIFIC NEWS.

[Mar., 1905.

British Association
Meeting, 1905.

Preparations are progressing for the meeting which is to be
held in South Africa commencing on August 15.

A Central Executive Committee has been constituted at
Cape Town, with Sir David Gill as Chairman and Dr. Gilchrist
as Secrfetary ; while local Committees have been formed at
Johannesburg and other important centres.

Sir David Gill, Mr. Theodore Reunert, and others have taken
a prominent part in the initial work. The South African
Association for the .\dvancement of Science are cordially co-
operating in the local organisation, and will join with the
British Association in attending the meeting.

The aim of the Council has been to secure the attendance of
a representative body of British men of science, including
specialists in various lines of investigation : and that, along with
the generous support of the people and authorities in South
.Africa, should go tar to ensure the success of the meeting and
to stimulate local scientific interest and research.

The Central Executive Committee in Cape Town have
invited as guests 150 members, who will comprise members of
the Council, past and present general officers and sectional
presidents, the present sectional officers, and a certain propor-
tion of the leading members of each section. To this list has
yet to be added, on the nomination of the Organising Com-
mittee, the names of representative foreign and Colonial men
of science, the total number of the official party being restricted
to 200, including the local officials. It is hoped, however, that
many other members of the Association will also attend the
meetirg.

Professor G. H. Darwin, F.R.S., is the President-elect; and
among the Vice- Presidents-elect are the following: The Right
Hon. Lord Milner, the Hon. Sir Walter Hely-Hutchinson, Sir
Henry McCallum, the Hon. Sir Arthur Lawley, Sir H. J.
Goold-Adams. Sir David Gill, and Sir Charles Metcalfe.

The Presidents-elect of the various sections are as follows: —

A. Mathematical and Physical Science — Professor A. R.
Forsyth. M.A., Sc.D., F.R.S.

B. Chemistry— G.T. Beilby.

C. Geology— Professor H. A. Miers, M.A., D.Sc, F.R.S.

D. Zoology — G. A. Boulenger, F.R.S.

E. Geography — Admiral Sir W. J. L. Wharton, K.C.B.,
F.R.S.

F. Kconomic Science and Statistics — Rev. W. Cunningham,
D.D., D.Sc.

G. Eigineering — Colonel SirColin Scott-MoncriefT, G.C.S.I.,
K.C.M.G.. R.E.

H. Anthropology— A. C. Haddon, M.A., Sc.D., F.R.S.

1. Poysiology— Colonel D. Bruce, M.B., F.R.S.

K. Botany— Harold Wager, F.R.S.

L. Educational Science — Sir Richard C. Jebb, Litt.D.,
M.P.

The Vice-Presidents, Recorder.s. and Secretaries of the 11
sections have also now been appointed.

In view of the numerous towns to be visited by the Associa-
tion, and in which lectures or addresses will be given, the
number of lecturers appointed is much larger than usual. The
list of these, as at present arranged, is as follows :--

Capi Town— Professor P.julton,on Burchell's work in South
Africa ; and Mr. C. V. Boys, on a subject in Physics.

Miritzburg— Professor Arnold, on Compounds of Steel.

J oh innesburg— Professor Ayrton, on Distribution of Power;
Professor Porter, on Mining; and Mr. G. W. Lamplugh, on the
Geology of the Victoria Falls.

Pretoria (or possibly Bulawayo)— Mr. Shipley, on a subject
in Zoology.

Bloemfontein — Mr. Hinks, on a subject in Astronomy.
Kimberley — Sir William Crookes, on Diamonds.

As the wish has been conveyed to the Council from .South
Africa that a few competent investigators should be selected
to deliver addresses dealing with local problems of which they
possess special knowledge, ageologif-t, a bacteriologist, and an
archwologist have been invited to undertake tliis work. involv-
ing in two cases special missions in advance of the m;iin party.
Whilst Colonel Bruce, F.R.S., will deal with some bacterio-

logical questions of practical importance to South Africa, Mr.
G. W. Lamplugh (by the courtesy of the Board of Education)
will be enabled to investigate certain features in the geology
of the \'ictoria Falls, particularly as regards the origin and
structure of the canon; and Mr. 1). R. Maclver, who is at
present exploring in Nubia, will proceed in March to Rhodesia
in order to examine and report on the ancient ruins at Zim-
babwe and also Inyanga.

Most of the officials and other members of the Association
will leave Southampton on July 29 by the Union-Castle mail
steamer Saxon, and arrive at Cape Town on August 15, the
opening day of the meeting ; but a considerable number will
start from Southampton on the previous Saturday, either by
the ordinary mail-boat or by the intermediate steamer sailing
on that date.

The sectional meetings will bo held at Cape Town (three
days) and Johannesburg (three days). Between the inaugural
meeting at the former and tlie concluding meeting at the latter
town opportunities will be offered to members to visit the Natal
battlefields and other places of interest. Subsequently a party
will be made up to proceed to the Victoria Falls, Zambesi ;
and, should a sufficient number of members register their
names, a special steamer will be chartered for the voyage
home, via Beira, by the East Coast route, as an alternative to
the return through Cape Town by the West Coast route.
Thus all the Colonies and Rhodesia will be visited by the
Association. The tour will last 70 days via Cape Town, or a
week longer via Beira (all sea), leaving Southampton on
July 29, and returning thither on October 7 or October 14.

A New View of the
Steers.

liy T. E. Heath.

The usual Star Maps represent the heavens, as we see
them, in perspective. The nearer stars therefore are
drawn of larger and the more distant ones as of smaller
magnitudes than they would be shown if it were custo-
mary to make plans and elevations of the Universe upon
which e\erything was true to scale. We are tlius con-
firmed in the tendency, to which we are naturally prone,
to regard ourselves, our Earth, and our Sun as the most
important objects in space.

Astronomers who now know, more or less correctly,
the parallaxes of a considerable luiniber of stars, being
accustomed to think of stellar distances in seconds of
arc, are not thus misled, but to the general reader
these angular measurements do not convey much idea
of distance. We are told that cne second of arc
(i"'Oo) is the angle subtended by a halfpenny, which is
one inch in diameter, at a distance of y26 miles; that
the parallax of the nearest star is only 0-75", and that
stars which have only a parallax of o-oi" can just be
measured. Astronomers tell us these things, but we
cannot easily think in these terms.

We, in this country, are accustomed to think ot small
spaces in inches and long distances in miles. Now it
fortunately happens that, if we represent the distance
which light travels over in one year by one mile, the Sun
upon the same scale will be represented by adot(.) only , ,',-
of an inch in diameter, the earth by a microscopic point
placed at a distance of exactly one inch and Neptune, at
the furthest known boundary of the Solar System, will
be only one pace (of 30 inches) from the Sun. If we
draw a map upon this scale, the nearest known star
would be 4,', miles from the Sun, and we can put down
all the stars of which the parallaxes are known upon
our Map and form a clear mental picture therefrom.

Mar., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

We will then place the Sun at Greenwich Observatory.
We shall need a table 5 feet in diameter to represent the
whole of the solar system upon. We will divide space
up into concentric spheres, the Sun being at their common
centres. These space spheres will on our map be repre-
sented by circles. The first circle we will draw with a

We' have 9 times the area of the first circle, but we must
recollect it represents a sphere of space, and is therefore
27 times the volume of the space sphere of 5 light-years
radius.

We shall here be able to map, including the first
sphere, from the stars whose parallaxes are known, in

OJUi J.CttAA -yj^tn^^xX. Co lUjUi ScoU

^^-o. /

'Si /

1^, ^, 8, Cj .10

II .It-, /!>, 114

— -.^ ^-^ii.''"-^», 'V /i", 16M7

/ /

7o6fo«ux.i^^'-"'M@(HtayL

Ziooo

radius of 5 miles, to represent a space sphere of 5 light-
years radius ; but we shall, besides the Sun, have here
only one star to locate. This will be a Centauri, and
we must place it 4-34 miles from the Observatory — it
will come near Bromley.

We will now draw another circle at 15 miles radius.

the Northern Hemisphere 14 stars, I central star (the
Sun), and 6 stars in the South. But the Southern Hemi-
sphere is, so far, less completely surveyed than the
Northern, so that we may e.xpect to add, say, 6 stars to
the South, making a total of 27 stars.

We have, therefore, a probable average of i star for

KNOWLEDGE & SCIENTIFIC NEWS.

[Mar., 1905.

M) (0) M" LY

< n r CtC \

\ "-Tits 4 • iPO k ^\

III?) SC<MJ>

•■■> ,iP M xT '■'< • SP
">' «n ««• o'oi '*» «l

i^' 9 „ w / L "M 15.000 $c««>

Fig. 2.

1905-]

KNOWLEDGE & SCIENTIFIC NEWS.

each space sphere of 5 light-years radius ; or, in other
words, the stars are probably at an average distance of
5'i3 light-years apart. The survey of star distances
beyond this radius is, at present, so imperfect that we
can draw no conclusions therefrom as to the stellar
density in space.

Professor Newcomb, however, says in his book on
" The Stars " that as far as the stars which have any
considerable proper motion go, they are pretty equally
scattered over the sky. These are the stars which are
presumably the nearest to us ; in fact, no measurements
we are likely to make will go beyond them, so that I will
assume as far as we have measurements the stars are at
intervals of 5'i3 light years apart.

We will double the radius for each succeeding sphere,
and, still measuring from Greenwich, we should enclose
withm the boundary of each space the total number of
stars marked A; but, so far, I can only find parallaxes
for those marked B.

Northern. Southern.

+ 12
+ 17
+ 19

We have now got as far as parallaxes will take us,
rather further indeed, for we can hardly place at their
true distances those stars added by the last sweep. Sir
David Gill, for example, says Canopus gives a parallax
of O'oo", but this only means he is sure it does not exceed
o-oii" (at least 296 light-years).

It will be instructive, however, if we continue making
circles, and assume the stars still average 5-13 light-
years apart.

At 960 light-years radius we enclose 7,007,888 stars.
1.9-0 ,, ,, ,, 56,623,104 ,,

lies Rad

us. A

216 stars

40 stars

1,728 ,,

56 ,,

120

13,824 ,,

70 -.

240

110,592 ,,

85 ,.

480

884,736 ,,

93 ..

1,920

3,840

452,984,823

But this is probably four times as many as the total
number of stars which could be photographed by pro-
longed exposure in the largest telescopes, and Dr. Isaac
Roberts has proved we thus reached the boundary of our
stellar universe, because all stars shown by exposures of
7 or 12 hours are also shown, down to the smallest mag-
nitudes, by only 90 minutes' exposure. The best
estimate I could find of the total number of stars of each
magnitude is by Mr. Gore(" Knowledge," 1901, p. 178).
He makes the total about 100,000,000 (probably about
70 per cent, are in the Milky Way).

This map I have described, on which light travels one
mile in one year, will cover England and stretch beyond.
It is too big to use. I have, therefore, constructed one
upon a much smaller scale, fig. i ; but to realise what it
means the large map should always be kept in mind.
Even so, I have only been able to set down the stars to
scale as far as the 30 light-years radius; beyond that each
circle on my map is supposed to be twice the radius of
the preceding one. It will be borne in mind that, as
'spheres of space are represented by circles on a plane
surface, t^vo stars which appear near together on the
map may Be really far apart. The distances froin the
Sun, however, and from the Equator are approximately
correct.

We are accustomed to think of gas and electric lights
as being of so many candle-power each. I have therefore
drawn the stars of different shapes, which distinguish
how many Sun-powers each star is. Within the 15 light-
years circle, for example, it will be found there are several
stars which give less light than the Sun, and some which

give more. It would take 200 stars as bright as
o A 1 1677 to equal the Sun, but it would take 36 Suns
to give as much light as Sirius, which is 8-8 light-years
away.

In the map the Sun, or a star of one Sun-power, is
drawn thus o, and three rays are added for a star of three
Sun-powers ; circles are added for tens, hundreds, &c. I
have however, in fig. 2, drawn the dimensions of the
stars compared with the Sun on the supposition that
equal surfaces give equal light. Probably this is true
only of stars of the solar type.

Though small stars are no doubt equally abundant at
all distances they are not equally noticeable. On our
map, therefore, we shall find the Sun-power recorded
increases with the average distance. For example, at
39 light-years, we get Vega 163 Sun-powers; at 40 light-
years, Capella 146 Sun-powers; at 76 light years, Achernar
400 Sun-powers; at 136 light years, Arcturus 1989 Sun-
powers ; and at from 270 to 480 light years, Rigel, Spica,
and Deneb, from 2500 to 9200 Sun-powers, and Canopus
at least 21,000 Sun-powers. To make my new view of
the stars I searched all recent astronomical works I could
find for the best estimates of parallax. I gave the pre-
ference to those made by Gill, Elkin, and at Yale. The
Sun-powers I worked out upon Professor Newcomb's
estimate that the Sun's magnitude is 26'4 (Gore says 26"5),
and, as far as I could, I used the Harvard estimates of
stellar magnitudes.

No doubt many of the data are uncertain, but the best
estimate obtainable is worth recording, though, if very
doubtful, I marked it (?). It is to be hoped we shall soon
have heliometer parallaxes for all the second magnitude
stars equal to those for the first, and that by photography
measurements will be reached for many small stars.

A model would be more instructive than a map. What
could be a fitter place than the dome of St. Paul's Cathe-
dral ? The Sun in the centre and all the Stars hung
round it, as their distances become known. They would
be incandescent globes, and the candle power of each
should be proportionate to the Sun-power of the star.

I'or a model, however, or for a small map, such as I
have drawn, to convey any real idea of the dimensions of
our stellar universe, the great world-spreading map I have
described should be mentally referred to; for in that the
Earth is actually one whole inch from the Sun and the
solar system no less than five feet in diameter.

I do not mean that we should think of space coming
to an end at a distance of 3800 light-years ; indeed, we
cannot think of it coming to an end at any distance. It
may well be that in the infinite ocean of space there are
many islands of light, of which our own stellar universe
is one; we cannot tell, for we are far out of sight of any
other land.

That our own stellar universe is limited is nearly cer-
tain ; for otherwise, if light-giving stars be scattered
throughout the whole of infinite space (unless perchance
they be eclipsed by the dead, dark orbs which also wander
there), the night would be as bright as the day, and day
and night the whole heavens around us would blaze with
an intolerable glory.

Lantern Slides.

We have received a supplementary list from Messrs. Newton
and Co. of their new lantern slides for lecture and other pur-
poses. These include series on Radium, Sand Figures, Rock
formation, Starry Heavens, Trees and Plants, and others of
a scientific nature.

KNOWLEDGE & SCIENTIFIC NEWS.

[Mar., 1905.

Q\ieei\sland
Sticks.

Fire

Some extremely valuable information on the Domestic Im-
plements, Arts, and Manufactures of the Queensland
natives is comprised in the Bulletin of North Queensland
Ethnography, which is presented to the Queensland Govern-
ment by Mr. Walter E. Roth, whose oflficial title is the
appropriate one of " Chief Protector of the Aboriginals."

.\mong other things described by .Mr. Roth is the process
of making " fire-sticks," and of using them to procure fire.
The fire-sticks are thin wands from two to four feet in
length, and arc often capped with a knob of beeswax and
leaf or of shells. The grass tree is the one from which the
fire-sticks are most often cul ; and Ihe process of firing-up
has not changed from the days in which Captain Cook
described it. " They take," said Captain Cook, " two
pieces of dry soft wood — one is a stick, the other piece is
flat ; the stick they shape into an obtuse point at one end,
and pressing it on the other turn it nimbly by holding it

between both their hands as we do a chocolate-mill,
shifting their hands up, and then moving them down on it,
to increase the pressure as much as possible. Bv this
method they get fire in less than two minutes, and from
the smallest spark they increase it with great speed and
dexterity." To make a beginning the horizontal stick niav
have a small excavation punched into it with a sharp stone,
&c., so as to give the extremity of the vertical one a firmer
basis of support, it being very liable otherwise to slip otT
the rounded edge. What with the firm downward pressure
and simultaneous twirling with the flats of the hands a
circular concavity ver\' quickly results : if a fresh one, some
charcoal dust may be placed in it. .As the concavity is
being formed the finely-triturated particles removed from it
collect like a miniature dust-heap •around its mouth. Piled
up on the underlying leaf or ground and covering over that
portion of the edge of the horizontal piece contiguous with
the excavation is a small pinch of fine dried-grass particles,
pith-dust, bits of the pricklv tops from the grass-tree, &c.,
arranged in such manner as actually to touch the edge of
the excavation, on a windy day especially, and commonlv
to save labour, the pile of dried grass, &c. — the " tinder " —
may be led up along an artificial nick extending from the
excavation to the edge. .As the finely triturated dust-
particles from the horizontal piece become heated,
blackened, smoked, burnt, and removed by the simul-
t;ineous twirling and friction a spark forms and comes into
contact with the tinder; directly this takes place the latter is
quickly whipped up, usually with a bunch of dried grass
swung round and round in the air, perhaps blown on, and
so made to burst into flame.

Hardly less interesting are .Mr. Roth's observations on
the " uses of the colours " among the aboriginals. White
is essentially the colour of mourning, sorrow, and tribula-
tion, and is met with during the ceremonies connected with
burial. But in some areas of the colony and among some
tribes it is a " fighting " colour, thus reversing in another
sense the practice of European nations, where the " white
flag " or the " white feather " have the precisely opposite
significance. The usual orifiamme of war, however, among
the natives is red. Red adorns warriors on their fighting
expeditions, and paints their weapons; it is also found on
their fire-sticks, and is even as'-ociated with magic. The
IBloomfield natives by holding out the red flag can ward off
impending danger from friendly spirits. On three rivers
and their hinterland, however, red is associated with death,
and the natives there .signify mourning by a red flower or
feather fixed to the forelock. Old men and women among
the Brisbane blacks wear red as mourning for their
children. Of less esoteric origin is the use of yellow.
Y'ellow is the colour for withstanding heat, and in the heat
of summer the natives cover themselves from head to foot
with yellow pigment. It is, as a decoration, a woman's
rather than a man's colour. Black is only used sparingly;
and on the only occasion when Mr. Roth saw natives en-
tirely covered with it they were representing " crows " at
some very high initiation ceremonies. Mr. Roth does not
agree with those who say that the natives possess unde-
veloped colour-sense or colour-vi'.ion. He ha-, found words
which indicate accurate subdivision of the princip.d colours.
White, in the sense of colour, is bilbin, dingga ; in the sense
of light, clear, &c., especially in the case of \\ aler, kandal ;
as a particular pigment, garmai. Red, in the sense of a
colour, is dini, and is also expressed as woba-dir, lit. with
the " woba " (a red pigment); in the latter case, the colour
is still associated with the pigment, much in the same way
as we speak of the terms " raddle " and " raddled."
Yellow is barga, the name of the particular pigment. Blue
is dalon ; the natives speak of purai-dalon, "water-blue,"
to distinguish deep from shallow water. There is no name
for green, the existence of which colour is certainly
recognised, but has not been dissociated from the objects,
grass, leaves, with which it is ordinarily connected. Grey,
although recognised, is appreciated f)nly in the term for
grey hair (pinga) as distinguished from the normal black
hair (moari). Chestnut is yetchel, but applied to .animals
only. Auburn hair is called " moari-ngalan " or sun-hair,
which is not unlike our expression of " sunny ringlets."

Mar., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

The Ears of Fishes.

By W'li.i RED Mark Webh, F.L.S., Honorary Secre-
tary of the Selborne Society.

With Illustrations from Photographs by the Writer.

Those who look only at the outside of a fish's head
may, perhaps, be pardoned for jumping to the con-
clusion that it has no ears because there are no external
evidences of their presence. At the same time we have
only to recall the accounts which exist of carp rcgu-

■ig. I.— The Right
semi-circular ca
5een from the oute

[.iiifliloiii i„i,^,ili-) of a Cod, showing the
large otolith or sagitta in position,
slightly enlarged.

larly coming to be fed at the sound of a bell to appre-
ciate that fishes hear, and, therefore, must have
auditory organs of some kind. Dr. Zenneck, of Strass-
burg, has also shown by special experiments that fishes
are sensitive to sound vibrations and are frightened
when an electric bell is rung under water. Care was
taken by first placing the bell in a pail to prevent any
disturbance of the water which might alarm the fish.
As a matter of fact, the ears of these animals are well
developed, and differ only in matters of detail from our
own; though in these very points of difference much
of their interest lies. If we look at the first illustration,
which is the photograph of the internal ear of the cod-
fish (I'ig. i), we shall see that the three semi-circular

Fig. 2.— The Large Otoliths of the Cod.

canals arc present which we find in the higher verte-
brates, and which it is generally supposed enable us to
judge of the position of our heads with regard to our
bodies and to the earth's surface.

We notice, however, that the spiral prolongation of the
sacculus, which we know as the cochlea, is absent frt)m
the fish, and we do not see the three small bones which
play an important part in connection with vibration in
the mammalia. There is a very good reason for this,
for in fishes these bones are still put to their original
use and form part of the ordinary skull. In bony fish,
however, we find otoliths, or stony structures (Fig. 2),
which may be of a large size and situated in special
parts of the internal ear. Many of these ear stones
are of peculiar shapes, and though the majority are
white in colour, they are usually finely sculptured in a
characteristic manner. There is no doubt that they
make an attractive collection, and are surrounded with
a good deal of interest, as we shall see.

We may first of all ooint out that there are typically
three otoliths, and their positions are shown on the ac-
companying diagram (Fig. 3) taken from a drawing
made bv Mr. E. T. Newton, of Jerm)^ Street Museum,

-circu/ar ra/eal

Sfmi - cum/ar

i-'ar/ul

Fi/rifcrm

LAPILLUS

-The Left Auditory Capsule of the Pike
side, showing the positions of the vari

(Modified frum a drimimj h,j E. T. Nar

M/'^c ijti/?if/ta/'

seen from the inner
'US otoliths,

in, F.R.>>.)

which he has been so kind as to put into my hands. The
largest otolith is the "sagitta," which lies in the
sacculus and is seen also in the first illustration. The
second is situated not far from the first in that part of
the ear which corresponds to the cochlea. The third
is in one part of the utriculus, and is called the lapillus.
The sagitta is usually the largest, and, therefore, is the
easiest to find, especially in fish that have been cooked
and brought to the table; for it is possible to pursue
the study of otoliths, on occasion, at meal times. Some
amusement can be had by those familiar with these ob-
jects at restaurants should small haddocks be served
up under the name of whiting. The flavour may lead
the diner to doubt the claims of the fish to its title, but
few external characters, if any, remain which would
piove it to be an impostor. Whitings and pseudo-
whitings perforce are cooked with the head in place,
and very little trouble will serve to make
matters quite clear. The large otoliths can easily I:e
removed with one's knife and fork from the back of the
skull and the species of fish determined without a doubt.
The sagitta in the haddock (Fig. 4) resembles that of
the cod (Fig. 2), though it is longer and somewhat
narrower in proportion, while that of the whiting
(Fig. 5) is produced into a long point and is larger com-
pared with the size of its owner. With this evidence
up one's sleeve, should one be acquainted with the

KNOWLEDGE & SCIENTIFIC NEWS.

[Mar., 1905.

manager of the restaurant, it is possible to approach
him and playfully accuse him of fraud. He will, of
course, stoutly maintain that the description on the
menu is correct. He will nevertheless probably state
his intention of consulting the contractor who supplies
him with fish, and on your next visit will inform you
that the fishmonger has owned that you were quite
right, though only one person in a thousand, if that, is

FifT- 4.- The Large Otoliths of the Haddock.

aware of the difference between the two fish upon which
you have based your contention.

As we have said before, otoliths have those charac-
ters which the collector of natural history objects is
accustomed to look for, and though brittle, they are
not perishable. They are not unwieldy; within limits
they present great variety of shape and size, if not of
colouring, and they form very pretty collections that

Fl|f. J. The Ijirgc Otoliths of the WhltinR,

cannot be brought together without just sufTicient
trouble to keep them from becoming too common.
There is fortunately another aspect from which such
a collection may be looked upon. \'cry little is known
about otoliths, and it is possible to form a very fair
idea of the structures and affinities of the fish whose
otoliths are found fossil by comparing them with ex-
amples from modern forms. As a matter of fact

some of our modern fishes have been proved to have
existed at the time that the red crag, familiar to
visitors on the East Coast, was laid down. Very few
collections of any size exist, and as one is necessary
to the geologist who wishes to study fossil otoliths,
Mr. E. T. Newton has formed an extensive one for
his own use. It is surprising how much trouble may
be taken and even danger experienced in obtaining

F.'g. 6 — The Large Otoliths or Kar Stones of the Hake (somewhat
enlarged).

a new fish of which the tiny otolith only remains to
remind the enthusiastic collector. We give photo-
graphs of one or two other car stones which are easily
obtained. Those of the cod are a fair size, while
those of the hake (Fig. 6) are much larger, compara-
tively. Those of fiat fish (Figs. 7 and 8) are fairly
characteristic. Turning to one or two others we may
point out that the ear stones of the salmon are not
particularly large, though in certain freshwater fish,
such as the bream, the three stones are well developed
and are more of a size than in many marine fish. The
sagitta of the pike has several very elegant points. That
of the gurnard has a slit at one end, while that of the
wrass is practically Y-shaped. The sagitta has as

Fig. 7

irge Otoliths of the I'lalce.

a rule a peculiar groove on one side which, as Mr.
Newton has found, presents features that are charac-
teristic of the different families of bony fishes.

Occasionally, hirge otoliths, like those of the cod,
have been used as emljrf)i(lcry, while those of some
Mediterranean species have been mounted to form
jewellery. Probably the taste which has arisen for
ornaments made from irregular pearly masses known

Mar., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

as " baroque ' has led to this, but it must be re-
membered that otoliths have the porcellanous texture
of the interior of the common oyster-shell and lack
the sheen and play of colours characteristic of mother-
o'-pearl.

• •

Fig. 8.— The Large Ear Stones of some other Flat Fish.

Turning now to other orders of fishes we find that
while g-anoids such as the sturg-eon have more or less
well developed ear stones, the cartilaginous fishes,
such as sharks and skates, have in the sacculus a num-
ber of separated grains instead of a solid mass.

Radivim— the Cause of
the Ea^rth's HeoLt.

Professor E. Rutherford, F.R.S., has written an
interesting and most noteworthy article in the Februar)
number of Harper's Magazine under the above title. After
referring to the controversy between Geologists and
Physicists regarding the age of the earth, he discusses the
cause of the heat in the earth and the sun, and points out
that while the heat supplied by possible chemical com-
bination is inadequate to account for this, the fact that
radio-active bodies are able to emit a great amount of
heat throws quite a new light on the question. " In the
course of a year," says this great authority, " one pound
of radium would emit as much heat as that obtained from
the combustion of one hundred pounds of the best coal,
but at the end of that time the radium would apparently
be unchanged and would itself give out heat at the old
rate." And it is probable, he adds, that it would continue
to do so for about a thousand years.

The author then describes how all radio-active bodies
must emit heat, although in lesser comparative amounts;
thus the heating effect of uranium is probably only
about one millionth part of that shown by an equal weight
of radium. Yet radio-active matter has been found to be
distributed, in minute quantities, throughout the atmo-
sphere and the crust of the earth. " These emanat ions are
not produced in the air itself, but are exhaled from the
earth's crust which is impregnated with radio-active
matter." Professor Rutherford then comes to a remark-
able conclusion. " Since the radio-active substances
present on the earth are continuously expelling a particles.

heat must be evolved in amount proportional to the
quantity of active matter present and to the intensity of
the radiations. The question then arises, is the amount
of radio-active matter present in the earth sufficient to
heat it to an appreciable extent ? I think that even with
our present knowledge this question must be answered
in the affirmative." In support of this he continues,
" Since one gramme ofradium emits enough heat each hour
to raise one hundred grammes of water through 1° C.,
a simple calculation shows that the present loss of
heat from the earth is equivalent to that supplied by
the presence of about 270 million tons of radium. This
amount may seem very large compared with the small
quantities of radium hitherto separated, but is small, for
example, compared with the annual output of coal from
the world. It can readily be deduced that this amount
of radium, if distributed uniformly throughout the earth's
crust, corresponds to only five parts in one hundred
million million per unit mass. This is a very small
quantity, and calculations based on the observations of
Elster and Geitel show that the radioactivity observed
in soils corresponds to the presence of about this propor-
tion of radium."

CORRESPONDENCE.

Spark Electrographs.

To THE Editors of " Knowledge."
Sirs, — Re spark electrograph shown in your last issue.
During a series of investigations, made nearly two years ago,

KNOWLEDGE & SCIENTIFIC NEWS.

[Mak., 1905.

of the phenomena preceding spark discharge, I had occasion
to make many electrographs showing the field between the
electrodes of the gap in the various stages of the strains
breaking down the di-electric strength of the air. The en-
closed are two of them. One shows the invisible brush which
evolves just before the spark passes — the other is of the tenta-
tive feelers being emitted by the positive prior to the formation
of the negative component.

As there is a considerable field open to experimenters in this
direction you may care to publish these electrographs.
Vours faithfully,

Alfred Williams.
Laboratory. Meadow House, Ealing, W..
February 6, 1903.

Photography.

Pure arvd Applied.

By Chap.man Jones, F.I.C, F.C.S., &c.

Time Development. — This means the treatment of ex-
posed plates to a prepared developer for a fi.\ed time,
which may have to be varied a little according to the
temperature and will not be the same for difTerent
developers or plates of difTerent makes, but which is not
varied to suit the subject or the e.\posure. The plates
are put into the developer for the specified time and then
fixed and washed without inspection. The \ise of the
Kodak developing machine renders the following of this
method obligatory, for inspection during development is
then impossible. There are modifications of time
development that allow for variations of temperature and
certain changes in the developer, but I refer now to the
simple method just stated.

There has been considerable argument and some dog-
matic e.xpressicn of opinion as to whether time develop
ment is advantageous, whether, indeed, there is any
advantage in any other method. The case in favour of
it was very strongly set forth by Mr. R. Child liajley, a
week or two ago, in a lecture at the Society of Arts, and
the Chairman, Mr. George Davison, emphatically sup-
ported the lecturer, showing prints from negatives of the
same subject that had received exposures of 1,2, 4, and 8
units of time, and had been developed together for the
same time. The longer the exposure the denser the
negative and the longer the exposure required for print-
ing from it, but the prints from these negatives were all
satisfactory and not very different from one another.

The advantages of such a mechanical method of
development are obvious. There is no light fogging —
for the plate may be kept absolutely in the dark ; the
fingers are not dabbling in the solution — for the plate is
not removed from the dish until the time is up ; all
doubt as to when development is complete is removed —
for any one can read a clock though few can tell by in-
specting an unfixed plate whether the image is satisfac-
tory ; in the Kodak machine a whole roll of exposures is
developed at once, so that much time is saved ; and all
risk of damage to the film is obviated because it is per-
fectly supported and not touched during development and
fixing. The question is what do we give up for these
very notable advantages ? Some say, Nothing, and that
what we imagine we lose is merely a matter of fancy or
sentiment. With regard to the vast majority of those
who develop photographs I believe this to be absolutely
true, and that the net result of adopting such a method
would be found to be a considerable gain in the

quality of the resulting negatives. But I also doubt
whether there are more than perhaps one in ten thousand
of those who do a little drawing find painting whose
drawings are worth as much as an ordinary photograph of
the same subject, and the fact that few excel is no proof
that i:one do or that it is impossible to excel. I am
con\inced that the same is true with regard to develop-
ment, and that with knowledge and practice, constant
practice, that is, not merely the developing of a batch or
plates three or four times a year, results may be obtained
that mechanical methods could not give. This leads to
another <]uestion : Is it worth while even for this excep-
tionally able and practised worker to bestow so much
trouble in personal and detailed attention when the tim-
ing method gives such an excellent yield of good results ?
I very much doubt whether it is unless he is engaged on
exceptional work.

It will be understood that these remarks are intended
to apply to ordinary photography as it is commonly
understood. But I have no doubt that much scientific
photography would yield a belter average of results with
less trouble if development were simply timed. For
exactly repeating definite results, the timing method
(using the same developer at the same temperature) is the
only way to justify the anticipation of success.

Improvements in Colour-Photography. — Messrs. Sanger-
Shepherd and Co., who have done so much to make
photograph}' in colours possible for any one who can
photograph at all, are introducing some notable improve-
ments in apparatus and methods. The repeating- iiack
camera is still to be preferred for subjects that permit of
consecutive exposures for the three negatives (the red,
green, and blue records), but the advantages of a camera
that gives the three negatives side by side on the same
plate by one exposure are so obvious that they do not
need pointing out. Such a camera they have just per-
fected. It has only one lens, so that the triple exposure
needs no more manipulation on the part of the photo-
grapher than if he were using any ordinary camera.
This means that there remain now no limitations in ihe
character of the thing or scene photoRraphcd other than
exist in ordinary non-colour photography, except that,
other things being equal, the exposure for the colour
photograph must be rather longer. Hut with the plates
now in use the length of exposure is very moderate. I
have seen a very good portrait of a dog which was taken
in ten seconds. The camera is compact, being no
larger than necessary to carry the plate in two directions,
and the size in the otiier direction is no more than
sufficient to carry the lens in the front and the plate at
the back as in ordinary apparatus. A very con\enient
size takes the half of a half-plate, divided longitudinally,
and a larger size the third of a 10 by 8 plate.

The same firm will shortly have on the market a
bathed plate — that is, a plate sensitised for colour after it
is made instead of being coated with an emulsion already
sensitised. The great advantage of such plates has long
been known, but 1 believe that they have not before been
obtainable commercially. The advantage is that they
are so much more sensitive to red and green that the
exposures for these colours are not very different from
that needed for the blue image. Such plates in the
camera mentioned above will require an exposure of only
one second instead of about fifteen for average subjects,
an advantage that will at once be appreciated by all
practical photograjjhers. With such an exalted sensitive-
ness to red, the plate has to be developed in the dark,
unless the photographer knows how, by keeping his dis-h
covered, and so on, to avoid light fog. The plates give
very clean and bright negatives.

Mar., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

ASTRONOMICAL.

The R^ecent La.rge Sun-Spot.

On the ^Sth of January a dark streak appeared on the sun's
eastern limb, which from its length, and the very extensive
masses of bright faculas surrounding it, gave promise of an
unusually large disturbance. On Monday morning, the 30th of
January, renewed observations showed that the spot was the
largest of any seen during the present increase of activity, and
in fact may have been equal to the great spot of February,
1894.

By means of suitable smoked or coloured glasses it was quite
easy to see the dark area of the spot on the sun's surface with
the naked eye. Observations with telescopic aid of varying
powers showed the umbra or dark centre of the spot to be
split up into several portions by intensely bright streaks or
'• bridges," and these were found to be constantly changing as
the sun was seen day after day. Towards the latter part of
its visibility numerous small umbrae were developed on the
following side of the main spot, this being a very common
feature of sun-spot evolution.

In accordance with the time of the sun's rotation, 25'38 days,
the spot reached and passed round the sun's western limb on
the loth of February, its path across the disc having had about
a mean southerly latitude of 16°. At its greatest development
the diameter of penumbra was about 2' of arc = about
53,000 miles The spectroscopic observations of the spot have
been most interesting and instructive. As might have been
anticipated from the rapid changes in the telescopic form of
the spot, the spectrum lines were observed to be considerably
distorted both to the red and violet sides, indicating strong
vortical disturbances to be existent in the spot area.
Frequently many of the special lines which are known to
be distinctive of spot spectra were seen to be bright, or
reversed, in comparison with the dark Fraunhofer lines. These
special lines, dark or bright, were identical with those observed
generally in spot spectra, and consisted chiefly of very faint
lines of the rare elements vanadium, scandium, titanium, and
some unknown element or elements.

Detailed accounts of magnetic measurements are not yet to
hind, but it is announced that on Friday, February 3, the
magnets at Greenwich Observatory were disturbed about
1.30 a.m., the effect showing throughout the day. Reaching a
maximum value towards midnight, the oscillation died away
on the morning of the 4th of February, about S.o a.m. It may
be noted that the large spot was near the central meridian of
the sun's visible hemisphere about the time of the magnetic
disturbance.

» » «

Jupiter's Sixth SaLtellite.

Shortly after the telegram from Professor Perrine announc-
ing his discover)- of a sixth satellite, there came an interesting
despatch from Professor Wolf, stating that one of the minor
planets photographed by him was very near to Jupiter, and
suggesting that this might be the suspected satellite observed
by Perrine. The following data give the co-ordinates of this
new asteroid, 1905 P.V. : —

R.A. = ih. 31m. 5gs. ^ Jan. 23d. yh. S'Sm. Koenigstuhl mean
Decl. = -f 8= 36' 13" ) time.

Daily motion in R.A. = -f- 23' ; daily motion in Decl. = — g'.

The day after, however. Professor Perrine sent a further
telegram, giving a new position for the satellite, and definitely
stating that the object discovered at the Lick Observatory is
not identical with the minor planet 1905 P.V. photographed by
Professor Wolf. This new position of the satellite was : —
K.A. = ih. 2im. 8s. I , j ou /r • 1 ^- s

Decl. = -1-7° 27' I January i7d.Sh. 44-3 (Lick meantime).

Obervations on the 17th of January gave the following co-or-
dinates of position of the satellite with respect to Jupiter : —
Distance (t-) = 36' > . , ,„ _

Position angle (6) = 266^ i' January i7702d. (G.M.T.)

* * *

New Form of Hydrogen in Stellar Spectra.

Hydrogen is well known to be present in the spectra of
most of the stars which have hitherto been spcctroscopically
examined, the spectrum usually shown being that consisting
of a rhythmical series of lines whose wave lengths are con-
nected by Balmer's law. In November, 1896, Profes.sor
Pickering announced that on the photographs of stellar spectra
obtained with the Draper Memorial telescope there had been
found a star which showed a new series of rhythmical lines in
addition to the ordinary hydrogen series. Subsequent dis-
cussion of their wave lengths elicited the important fact that
they were undoubtedly due also to hydrogen, but indicated
conditions of temperature and pressure hitherto unknown.
This star was f Piippis, which, having a southerly declination
of 39° 43', was unfortunately inaccessible to the astronomers
of northern latitudes. Quite recently, however. Professor
Pickering has been able to announce that by examination of
later photographs of stellar spectra it has been discovered
that the star \ Cephci has a spectrum identical with that
of s" Piippis, and as this star, of declination -j- 5S- 56', attains a
considerable altitude in northern latitudes, the instruments of
European observatories will be available for its examination.
It is somewhat unfortunate that it is a much fainter stir
than s" Piippis, its magnitude being about 5-6, but with the
large prismatic cameras which are now installed at many
observatories this will not prove a serious drawback to its
being observed.

* * *

Ephemeris for Observations of Comet
1904 d.

(120 midnight, Berlin Mean Time.)

The following positions have been computed by Ebell at
Kiel Centralstellc : —

1905.

R..\.

eclina

,on.

Brightness.

March

61"

287

062

424

■iro

8-2

203

0-58

31 8

42-8

53-2

0-54

.51

12-5

1 1'

t>3

21-4

."JO

299

i>i

379

050

45-5

t>3

526

59-3

5-6

047

Brightness in terras of that en 1904, Dec. 17

BOTANICAL.

By S. A. Sk.\n.

Several plants of more than ordinary interest are figured and
described in the last part of " Hooker's Icones Plantarum."
Thiseltnnia, a little plant with narrow leaves and small white
flower -heads, belonging to the Aski- family (Composita;), and
Efichsciiia, a leguminous plant, with yellow, purple-striped
flowers, are two new generic types discovered, in addition to
several new species, by Mr. G. H. Thiselton-Dyer in West
Australia. On plate 2785 is depicted the Chinese representa-
tive of the genus Liriodcndvon. Formerly it was regarded as
a variety of the well-known Tulip Tree of eastern North
America, which it very closely resembles. It seems extra

KNOWLEDGE & SCIENTIFIC NEWS.

[Mar., 1905.

ordinary that these two species should be so widely separated
geographically — one in eastern North America and the other
in West China. In his " Sylva of North .\merica," Sargent
says that the genus was represented by several species in the
Cretaceous age, which were widely distributed in North
America and Europe. It continued to exist during the
Tertiary period, with a species hardly different from /,. tidij'i-
fera, extending over eastern North .America and Europe as far
south as Italy, until the advent of glacial ice destroyed it in
Europe. It may be remarked that the .American Tulip Tree
furnishes the well-known whitewood, a light, easily worked
wood often used in electric light installations. A remark-
able variety of the Mahogany Tree is figured. The specimens
shown were in the seedling state, and had grown only six to
ten inches high when flowers were produced. Several plants,
among them the common oak, sometimes behave in the same
manner.

« » »

One would scarcely expect to find the original description of
a new plant in the "Geographical Journal." There is one,
however, in the February number, where a remarkable new
Alga, named Ckmcntsxa, in honour of the President of the
Royal Geographical Society, is described by Mr. George
Murray. An unusual amount of interest is connected with
this tiny plant. It was the first new organism discovered on
the Antarctic expedition sent out under the command of Cap-
tain Scott. Curiously, though a marine Alga, its nearest
known allies arc found in fresh water, and it reminds one, on
looking at the plate furnished with the description, of a
Glteocapsa. The material was collected by Mr. Murray him-
self off Brazil, lat. 7" - 12° S., long. JO" - 33° W. The name
selected is unfortunate, as Ctementsia is already pre-occupied,
having been given by Dr. Rose, of the U.S. National Museum,
to a Crassulaceous plant, formerly described as a Sciiiiiii.
This CUmentsia is commemorative of Professor F. E.Clements,
of the University of Nebraska, and if a valid genus the name
should remain, while the Alga will have to be provided with a
new one.

« * •

Monsieur Pee-Laby, in the " Revue Generale de Botanique "
for December, 1904, records the curious instance of a plant of
the common passion-flower (Passiflora cariiUa) having taken
upon it.self a semiparisitic existence. A seed by chance was
sown near a plant of Euonymus japoiticus. On germinating
apparently normal aerial parts were produced, but below the
surface of the soil a union was effected between the passion-
flower and the roots of the Eiionymiis, resembling that which
takes place between a stock and scion in grafting. A number
of roots developed on the passion-flower, so that it was not
wholly dependent on the host-plant for its supply of food from
the soil.

CHEMICAL.

By C. AiNswoRTH MiTCHFLi,, B.A. (Oxon.i, F.I.C.

The Copper Trea-tment of Wa-ter.

During the last few months the new method of purifying
drinking water by treatment with copper sulphate has been
extensively adopted by large waier companies in the United
States, where previously some had had to discontinue the use
of certain reservoirs owing to the growth of green alga; (" pond
scum ") rendering the water absolutely unfit for use. It has
been proved that salts of copper possess extraordinary anti-
septic powers, far exceeding those of either carbolic acid or
formalin, and that the addition of as little as i part of copper
sulphate to 5 million or even 50 million parts of the water is suffi-
. cient to destroy these low forms of plant life within three or four
days. At the same time the growth of higher plants, such as
watercress, is not injured, and the treatment is now being suc-
cessfully applied to the watercress beds in the Southern States.
In Professor Kracmer's opinion this difference in the behaviour
of the higher plants and of alga; is due to the fact that the
latter are unicellular, so that the entire functions of the
organism are simultaneously affected, whereas in higherplants
the copper can be distributed among the different cells and

its toxic action diminished. Bacteria being also unicellular,
it is not surprising that they, too, are destroyed by copper,
though they off^er greater resistance than the alga. Thus Dr.
Moore, of the U.S. Department of .Agriculture, has found that the
addition of i part of copper sulphate to 100,000 parts of water
destroys the micro-organisms of typhoid and cholera within
three or four hours. In one experiment a strip of copper
placed in water containing some 4000 typhoid bacilli rendered
the water sterile in four hours. .As regards the influence of
copper upon the human system, several leading .American
medical authorities have recorded their opinion that the traces
of the metal in water treated by this method could not possibly
be injurious. Copper is normally present in different kinds of
food, and is eaten in large quantities in preserved peas, a tin
of which contains many hundred times as much copper as is
present in the treated water. Their general conclusion is that
copper and its salts are much less poisonous than has hitherto
been supposed, and that they are not cumulative in their
action.

* * *

BuffaLlos* Milk.

The composition of buffalos' milk difl'ers greatly from that
of the cow, as has been shown by recent analyses made by
Herr Windisch of the milk from three buffalo cows. It con-
tained from 18 to 20 per cent, of solid substances, of which
/•g to 9'2 per cent, was fat (cream) and 077 to o'S3 per cent,
mineral salts. The milk of an average cow contains about
izh per cent, of solid matter, of which about 4 per cent, is fat
and about o\S per cent, mineral salts. Elephants' milk is still
richer than that of the buffalo, for it contains about 30 per
cent, of solid matter, including 20 per cent, of cream ; while
the richest of any known milk is that of the porpoise, with 60
per cent, of solid matter and 46 per cent, of cream. The milk
sugar in buffalos' milk amounts to about 4^ per cent., as
against about 4 per cent, in cows' milk, 20 per cent, in ele-
phants' milk, and only ij per cent, in porpoises' milk.
« « •

Yello\v Arsenic.

Messrs. Stock and Siebcrt have shown that when arsenic is
heated in a tube from which the air has been exhausted, it
condenses on the sides in a brilliant yellow coating. Arsenic
is best known as a grey substance with a metallic lustre, and
the yellow modification is slowly re-converted into this ordi
nary form when exposed to sunli,L;lit, and rapidly changed when
heated in the air. This is an interesting illustration of what
the chemists term "allotropic modifications." Chemically the
substances are identical, like blacklead and the diamond : but
they differ in physical properties, such as density, hardness,
and melting point.

ORNITHOLOGICAL.

By W. P. PvcRAi-T, A.L.S., F.Z.S., M.B.O.U., &c.
Great Snipe in Shetland.

The "Annals of Scottish Natural History" for January
records the occurrence at Unst of a (ireat Snipe {Callina^o
major) which was killed on Sept. 30, 1904, and weighed -j], ozs.
The I'^ditor remarks that if this record is authentic then it
makes the second record for the Shetlands. The doubt here
expressed is begotten by the weight, which he seems to regard
as somewhat light for this species, since the Common .Snipe
sometimes turns the scale at 7J ozs. Mr. J. E. Harting, how-
ever, in his valuable handbook, records the weight of the
Solitary or Great Snipe as varying between 7.' and 10', ozs.
» ♦ »

The Bea.k of the Hawfinch.

It may be of interest to the readers of this column to know
that in examining some skulls of the Common Hawfinch a few
days since I found two skulls still retaining the beak-sheath.
On examining these I was surprised to find in the region of the
gape, on the inner side of the lower jaw, two large rounded
bosses of the size of peas, and having a finely striated surface.
On the roof of the palate immediately above, I found an

Mar., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

oblong, cushion-like boss, similarly striated, and stretching
across the jaw from one side of the tomium, or cutting edge of
the beak, to the other.

These are evidently crushing pads, and recall the similarly
shaped teeth of certain elasmobranch fishes, and of Cyaiiiochis
among the Reptiles. So far I have not been able to find any
reference to, or description of, these pads.
* * »

The Emperor Penguin.

Dr. E. .A. Wilson, the .Assistant-Surgeon and Naturalist of
the " Discovery " expedition, gave a most interesting account
of the life-history of the Emperor Penguin at the Royal In-
stitution on Friday. January 27.

Hitherto nothing was known of the breeding habits of the
Emperor Penguin (Aptiiwciytfs forstcri), and consequently all
will appreciate the immense amount of trouble and hardship
that had to be encountered in order to track this bird to its
fastnesses.

It has been stated more than once that the penguins la}'
but one egg, and carry this in a pouch ! Dr. Wilson confirmed
the opinions of those who had expressed grave doubts as to
the probability of this story, and showed, by means of pictures
thrown upon a screen, exactly how the duties of incubation
were performed. In the case of the Emperor Penguin, the
egg, and, later, the chick, is supported on the upper surface of
the feet and overlapped by the feathers of the abdomen.

The coloration of the young is remarkable, inasmuch as it
differs from all other penguins. The upper surface is almost
white, the under surface somewhat darker, while the head is
velvety black, relieved by a conspicuous white face.

The position assumed during sleep by these birds goes far
to show. Dr. Wilson remarked, that the penguins once possessed
the power of flight, since they still thrust the beak down
between the now flipper-like wing and the body, though from the
peculiarly close-fitting plumage characteristic of these birds,
the comfort to be derived from such an attitude at the present
day must be a minus quantity !

Why is it, the lecturer asked, that these birds choose the
coldest part of the Antarctic winter for breeding ?

Two " rookeries " were visited during the expedition; one
at Cape Crozier, and one at King Edward's Land. The latter
was by far the larger of the two. and, apparently, the more
favourable as a nursery ; for at Cape Crozier he estimated
that the mortality among the chicks reached the amazing rate
of 77 per cent. !

Save at sea, these birds appear to have no enemies, but the
hunt for food is attended with many perils, the leopard seal
and the killer whale displaying a great fondness for penguin
meat.

Dr. Wilson is preparing a detailed account of his observa-
tions for the Royal Society, and on this account we forbear
from giving further details of his discourse.

ZOOLOGICAL.

By R. LVDEKKER.

The Speed of AnimaLls.

Much interest attaches to a note by iMr. Thomp.son Seton oa
the speed of certain animals which recently appeared in the
Field. The observations were taken by the author himself
with a stop-watch, and record the best speed for a mile of the
various species. Although the best record for a race-horse is
at the rate of nearly 35 miles an hour, Mr. Seton gives the
first place to the greyhound, with a rate of 34 miles an hour.
Then follow the racehorse with 32, the American prong-horn
antelope with 30, the .American "jack-rabbit" with 28, the
common fox with 26, the coyote or prairie-wolf with 24. the
foxhound with 22, and the American grey wolf wilh 20. A man's
best speed works out at the poor figure of 14 miles an hour,
while an ordinary runner who can do his mile in five minutes
moves only at the rate of 12 miles in the hour. In comment-
ing on this note, a second writer considers that the speed of the
horse is under-estimated.

The Stoatts of Jura and Islay.

To the .1 nnah of Scotthh Natural History for October Captain
I?arrett- Hamilton contributes some notes on the stoats of the
islands of Jura and Islay. From both islands the stoats, as
contrasted with those of the mainland, arc characterised by
their inferior size, relatively larger tail and ears, and certain
peculiarities in the skull. These features are most marked in
the Jura examples, those from Islay being somewhat larger.
The occurrence of a stunted race of stoats in these islands
with relatively large ears might, according to the author, be
readily .accounted for if food were scarce and good hearing an
important aid in the capture of scanty prey. The increased
length of tail is, however, less easy to explain. Although
Captain Hamilton believes these stoats to indicate a distinct
local race of the species, he has not yet proposed a special
name for them. •::- -:; ~.-

The Musk-Ox in Engla.nd>

Among the numerous species of large mannuals whose bones
are to be met with in a sub-fossilized condition in the gravels
and other superficial deposits of this country is the musk-ox
(Ovibns moschatus), an animal now confined to Greenland and
the barren grounds of Arctic America, but which had a wide
range in the northern part of the Old World during the
Pleistocene Age. The musk-ox was first added to the extinct
British fauna in 1875 by Messrs. J. Lubbock (now Lord Ave-
bury) and C. Kingsley, on the evidence of a portion of a skull
dug up in a gravel-pit near Maidenhead ; and only six or seven
other occurrences of remains of the same animalfrom British
formations have been subsequently recorded. Recently, how-
ever. Dr. C. W. Andrews exhibited before the Zoological
Society the hinder part of the skull of an old bull nmsk-ox,
showing the characteristic bases of the horn-cores, which had
been obtained from a gravel-bed at Frampton-'on-Severn,
'Gloucestershire ; and he also referred to a few bones of the
same species, comprising the second vertebra of the neck and
portions of the radius and femur, from the brick-earths of
Plumstead. The remains of the Pleistocene musk-ox indicate
a larger animal than its living representative, although, in the
opinion of Dr. Andrews, the difference is not sufficiently great
to render it advisable to regard the former as a race apart.
If this opinion should be reversed, the name Ovibos moschatus
pallcisi is available for the Pleistocene animal.

A White Annerica.n Bear.

Hitherto the polar bear {L'rsus iiiaritimus), which differs
very markedly from its kindred in the characters of its skull
and teeth, has been supposed to be the only pure white
member of the group. Mr. W. T. Hornaday, in the Report of
the New York Zoological Society, has, however, recently
described four skins, together with portions of the skull, from
British Columbia, which indicate a bear nearly related to the
common American black bear (Ursiis ainericanus), bat creamy-
white in colour. As this small white bear seems to be fairly
common in one part of British Columbia. Mr. Hornaday (who
cannot believe that it is a mere family of albinoes) regards it
as a new species, with the name of I'rsns kcrinodci.

Papers R^ead.

In our last month's issue the name of Mr. H. D. Imms is
misprinted Jenner, the writer not having had an opportunity
of revising the proofs. At the meeting of the Zoological
Society on January 17, in addition to the papers recorded
in the issue just referred to. Dr. C. W. Andrews, exhibited
and described the fossil musk-ox skull from Gloucestershire,
mentioned in an earlier paragraph; while Mr. H. E. Dresser
brought to the notice of the fellows three new species of birds
obtained during the Lhasa expedition. The papers read
at the meeting of I'eliruary 7, included one by Mr. N.
Annandale, on abnormal tadpoles from India ; a second by
Mr. G. A. Boulenger. on East African fishes : a third by Dr.
R. Broom, on some points in the anatomy of the extinct reptile
Diadiinodon ; and a fourth by Mr. G. L. Bates, on the mammals
of the Southern Cameroons and the Benito district. Mr.
Bethune-Baker also described a collection of Heterocerca
from Fiji, Mr. Beddard discussed the arteries in the brains of
birds, while Mr. Yearsley discoursed on the function of the
antenna of insects. .At the meeting of the Linnean Society
held on February 2, a paper by Dr. H. J. Hansen, was read on
European Cirolanina (Isopoda.)

KNOWLEDGE & SCIENTIFIC NEWS.

[Mar., 1905.

REVIEWS OF BOOKS.

A Popular Guide to the Heavens, by Sir Robert Stawell Ball,
LL.L)., r.K.S. iG. I'hilip and Son ; price 15s.net). This book,
of a bandy size (7 inches by S| and handsomely bound, c.in-
sists chiefly of a number of charts, di.igrams. And photographs
ranging through all branches of astronomy, accompanied by
some So pages of explanatory matter. It forms what may bo
called a richauffi of a former worli of Sir Robert Ball's which
has long been out of print, but has been so greatly amended
and added to as to form a new book. The author, in the
preface, describes the work involved in the preparation as
having been '• very onerous," but records his indebtedness to
Mr. Hioks for selecting the new plates, as well as for the
preparation of the text which accompanies them. Among the
more novel features are a series of 12 tinted illustrations of the
moon in different phases, each being accompanied by its own
full-page key-map. These, rather coarsely drawn, seem to us
hardly worth the space bestowed upon them, especi.ally con-
sidering that there are besides a complete chart of the' moon
in four parts, showing all the conspicuous features, as well as
three fine photographs giving a good idea of the appearance of
the lunar surface when viewed through a powerful telescope.
The 12 monthly maps of the stars may also seem somewhat
superfluous, being on so small a scale (4.^, inches diameter) and,
of course, containing repetitions of most of the constellations,
while they are followed by 20 sectional star maps on a larger
scale, as well as two key-maps. These sectional maps are on
the conical projection as in .Argelander's Durchmusterung
.Mlas, the stars being printed in black on a light blue ground,
and are reprints of those which appeared in I he older atlas.
The book will form a very complete and reliable handbook for
all students of astronomy.

Light Energy: its Physics. Physiological Action, and Thera
peutlcs. By Margaret A. Cleaves, M.D. (London: Kubinan
and Co.; price, 21s. net).— Ur. Margaret Cleaves divides her
book rightly into two portions. In the first of them she
assembles the known laws and theories of light energy from
the aspect of physics; in the second she subjects the whole
number of authenticated cases of light therapy to a critical
examination and analysis. To the first part of her task she
brings an excellent appreciation of essential points and an
admirably clear method of expo.sition ; and for the considera-
tion of the medical and surgical aspects of " the light cure,"
she comes equipped with eleven years of practical experiment
and investigation of actual cases. The opinions formulated
by other investigators have been carefully analyzed, and the
conclusions drawn therefrom submitted to searching criticism ;
and no case and no evidence are admitted to her p.igcs with-
out having shown the clearest right to be there on authenti-
cated evidence. The result of this inclusive but fastidious
method has been to present in one volume the whole of the
present accredited facts concerning light therapy, with an
accompaniment of illuminating exposition and suggestion.
The various forms of light treatment— sim baths, arc light,
incandescent light— are considered and described ; and the
relative efficiency of the large lamps, such as were used by
Finsen, and the smaller lamps, such as have in many hospitals
(the London Hospital, for example) supplemented or replaced
the larger ones, is discussed. According to Miss Cleaves, the
great advantage of a lamp of high power, such as the I'insen
arc lamp, is that not only does the patient receive the short
high frcfiuency rays of great chemical activity, but also the
waves of greater length with greater penetrability. The
smaller lamps are taking in the longer waves. The applica-
tions of coloured lights and the rays at the invisible end of the
spectnim are discussed, and the rays proceeding from radium
and thorium, "the poor relation of radium," are considered
from the therapeutic point of view. The value of the effects
of radioactive emanations as demonstrated by actu.al cases is
examined and discussed. The last two chapters deal with the
methods of sensitising tissues to the action of light, in some
cases by the ejection of fluorescent substances, and with the
destructive effect of light in some conditions of the skin or of
the organism. Ilr. Cleaves" compilation is an extremely valu-
able one, with every recommendation of thoroughness, clear-
ness, and the properly judicial attitude.

Three volumes are before us of the " Shilling Scientific
Series" (T. C. & E. C. Jack), is. e.ach. To design.ate these
as scientific works is perhaps somewhat a misnomer, compris-
ing as they do but elementary and " popular " accounts of certain
subjects which may have some scientific connection. " Balloons.
Airships, and Flying Atachines," by Miss ticrtrude Bacon, is the
first of the series. This is a simple but accurate rhiimi- of the
history of .-Veronautics. It contains a numberof very indifferent
illustrations, and a few novel expressions (one, for instance,
which w e would not however pronounce to be incorrect, is " Mr.
Edward Spencer, grandfather of the present well-known firm
of aeronauts "). The book bears no date, which is always apt
to be misleading, but it is presumably only just published, and
might therefore have been brought more up-to-date, for there
is but the briefest reference to the Lebaudy airship, which has
been so much to the fore of late. An index would certainly
enhance the value of the book. But these are all the faults we can
find, and anyone requiring a short but complete and reliable
account of what has been accomplished in navigating the air
can nowhere find a better guide than this. The next volume
of the series is " Motors and Motoring," a very practical little
h.andbook by Professor 11. J. Spooner, essentially, as stated,
for novices. It is most satisfactory to find such an abundance
of good information compressed into so small a space. The
general principles of motors arc fully described without
digressing on the many varieties of detail now to be met with
in the various makes of car. There are many clear diagram-
matic figures, which render the description of the mechanism
quite comprehensible to the learner. Explanatory annota-
tions are a feature of the book, which add to the clearness,
while not introducing too long a description of any one detail.
The third volume is " Radium Explained." by Dr. W. Hampson,
and here we are led more into the realms of true science, for
not only is there a wonderfully complete account of what is
known of Radium, but many other side issues, such as the
Structure of Matter, Ionization, Theories of Gravitation, and
Stellar Systems are gone into. This is all explained in simple
language, and the little work, by so good an authority, should
prove most useful to those wishing information on this
subject.

The Zeiss Works and the Carl Zeiss Stlftung. by Felix Auer
bach, translated from the German by S. F. I'aul and Fred. J.
Cheshire (Marshall, Brookes and Co.), 2s. 6d.. is an interesting
account of this well-known establishment. " It is by no means
as well known as it ought to be that the Jena enterprise is dis-
tinguished not only by the excellenceand variety of the instru-
ments turned out by its workshops, but even more by the
unique character of its organisation and the conduct of its
business." This little book gives a very complete history and
description of the whole affair, and appears just at the time
when we read of the unfortunate loss of one of the principal
actors, Professor Abbe. After briefly noticing the early history
of optics, the author tells of the new era of microscope con-
struction, the formation of images of non-luminous objects, the
new glass, and the Photographic, Astronomical, ;ind Measur-
ing-Instrument Departments of the works. The" Stiftmig " or
" Trust " is then described. This was founded by .Vbbe, who
had eventually, in 1888, succeeded Carl Zeiss as the sole pro-
prietor of this great works. In his unselfish generosity he con-
sidered that he had no claim to be considered as a capitalist
who had risked his money in founding the concern, and
accordingly handed over the administration of the business to
the " Stiftung " or co-operation of the oflicials .and workmen
of the works as well as the I'niversity and community of Jena.
The employees are thus remunerated under two heads, a fixed
wage and a result of the year's trading.

Botany. — "Trees" (Cambridge, at the University Press).
Volume II. of Professor Marshall Ward's admirable " Hand-
book of I'orest- Botany for the Woodland and the Laboratory "
deals with leaves. It treats of their external features, as well
as of their anatomical and microscopic structure, and the
metamorphoses which they undergo. Professor Marshall Ward
lays great stress on the educational value to the student of
the ability to draw and describe accurately the pcculi.irilies
of leaves, ar a thorough comprehension of the conformation
and adaptations of the leaf is "the key to the morphology of
the higher plants." The language used is never unnecessarily
technical, and nuich value is added to the work for students
by the numerous and excellent illustrations.

Mar., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

X-Rays: Their Employment in Cancer and other Diseases.

By Richard J. Cowen (London, Henry Glaisher ; price, js. 6d.).
— In Dr. Cleaves' bool< the Roentgen ray has not been con-
sidered, althongh it properly bslongs to a consideration of
light energy, becanse in the author's opinion the subject has
been exhaustively treated by other writers. Mr. Cowen's
book on the X-rays is not an exhaustive treatment ; and
makes no effort to summarize either results or conclusions.
It only aims at selecting such details of X-ray treatment as
may be of assistance to those practitioners who desire to make
use of it ; and to give hints concerning the use of apparatus
and the methods and times for exposures. Incidentally, the
book may be of service in disclosiug to the general reader the
probable limits of usefulness in this method of treatment and
in dissipating some of the unfounded expectations of cures
arising from it.

Practical Exercises in Chemical Physiology and Histology.

Arranged by H. B. Lacey and C. A. Pannett (Cambridge:
Heffer and Sons. Loudon: Simpkin and Marshall). — In this
capital little book of instruction for practical work, in which
the experiments to be made are annotated for the student's
benefit with the results to be looked for, Mr. Lacey and Mr.
Pannett have hit the best road, if not the royal road, to learn-
ing. The description of the chemical compound to be
analysed heads each exercise like the statement of a problem
or a theorem ; its methods of analysis follow like a problem ;
and the statement of the results to be expected from chemical
treatment or analysis give the key to the problem. The
exercises have been arranged on a course which has been
found practicable in the senior classes of day science schools
and in evening classes, and which will be found to meet the
requirements of students preparing for physiology examina-
tions— Stages I., II., and III., and Honours of the Science
Department of the Board of Education. Some of the results
obtained from the analysis of popular meat extracts have an
interest for a larger section of the general public than is com-
prised among science students.

The Geographical Journal, Vol. XXIV., July to December,
1904 (Royal Geographical Society). — This is an exceptionally
interesting volume, containing as it does the Presidential
Address for 1904, the Summary of Proceedings of the National
Antarctic Expedition by Captain Scott (forwarded from New
Zealand), account of the Swedish .\ntarctic Expedition by Dr.
Nordenskiold, account of the German Antarctic Expedition,
and finally an account of the Antarctic Meeting at the Albert
Hall and presentation of medals to Captain Scott. So that,
accompanied by a number of good maps, there is a very com-
plete record of what has been done in antarctic exploration in
recent years. Besides this there are several specially notable
papers, such as Major Powell-Cotton's narrative of his journey
through Northern Uganda, the Rev. A. B. Fisher's account of
Western Uganda, and the scientific results of Dr. Sven Hedin's
Last Journey. There is also much in this volume about the
Bathymetrical Survey of the Fresh Water Lochs of Scotland,
and the usual interesting assortment of Geographical records,
with many illustrations and maps.

Wellcorae's Photographic Exposure Record for 1905 (Burroughs
Wellcome & Co.), is. and is. 6d. — This neatly-got-up little
pocket-book has several new features this year, amongst others
being that the monthly light tables are so arranged that they
may be torn out as done with each month, and a number of
blank ruled pages form the Exposure record. The book is
replete with information on the development, toning, intensi-
fication, exposure, &c., of photographic plates, and contains a
diary, memoranda, and many useful tables, ending up with a
revolving exposure calculator.

The same firm (Messrs. Burroughs and Wellcome) ssnd us
some interesting pamphlets on their exhibits at the St. Louis
Exposition, which indicate in a concise manner the size and
completeness of their Physiological and Chemical Research
Laboratories.

We have received for review three new volumes of " The
Model Engineer Series" (Percival Marshall and Co.; price
6d. net). Model Steam Turbines, by Mr. H. H. Harrison,
lays down the principles on which these engines may be
designed. It is clearly written and fully illustrated. " Small

Electrical Measuring Instruments, published anonymously,
is designed for the use of those who are engaged in the con-
struction of small-power dynamos or electric motors, &c., and
who want to make simple tests and measurements when build-
ing and using them. The explanations given are of a simple
rather than an advanced nature. The Beginner's Guide to
the Lathe, by Percival Marshall, A.I.Mech.E., is addressed,
as its title suggests, to novices in the use of that fascinating
instrument. It is well designed to suit its purpose, and the
appliances suggested are of a simple and inexpensive kind.

How a Steam Engine Works, by W. E. M. Curnock
(Dawbarn and Ward). Od., is a practical and handy little guide
for those wishing to learn the principles and practice of the
steam engine, illustrated with clear diagrams. How to Read
a Workshop Drawing, by W. Longland is another little
book of the same series, which clearly explains all the
different " conventionalities " of machine designs and draw-
ings, and is well worth perusal by those who have not been
instructed in such matters.

The copyright of that most useful and popular handbook.
•' Half Hours with the Microscope," by Dr. Edwin Lankester,
formerly published by Messrs. W. H. Allen and Co., has been
acquired by Messrs. C. -Arthur Pearson, Limited, who have
also purchased the companion volume by Thomas Davies, on
the '• Preparation and Mounting of Microscopic Objects." The
latter has been out of print for some time, but a new and
cheaper edition will be published very shortly.

Rendering Celluloid Incombustible.

In order to overcome the undesirable quality of celluloid to
gnite, a French chemist has adopted the following method :
An ether-alcohol solution of celluloid is made ; then an ether-
alcohol solution of ferric perchloride. The two solutions are
mixed, and a clear, syrupy liquid is obtained, of yellow coHur,
yielding no precipitates. The liquid is poured into a suitable
vessel and is left for spontaneous evaporation, and a substance
of shell-colour is produced, which, after washing and drying,
gives the desired result. The celluloid thus treated loses none
of its properties of pliability and transparency, and is not only
uninflammable, but is also incombustible.

•Another method by which the celluloid may be rendered
uninflammable, based on the same principle, consists in
mixing bromide of camphor with cotton powder, adding castor
oil to soften the substance so that it may be less brittle. This
product, though more easily prepared, is, however, not incom-
bustible like the former preparation.

" Solidified Raindrops."

Mr. Wilson A. Bentley, writing in the Monthly Weather Re-
vicii.' (October), gives an account of studies of the comparative
sizes of raindrops extending from iSgg up to the present time.
The method of comparison consisted in letting the rain fall
into a dish containing fine flour, and the size of the dough pellets
formed aftorded a measure of the size of the drops producing
them. For small drops, the pellet was found by laboratory
experiments to be almost exactly the size of the drops, but
with large drops a certain flattening out took place. The
method is very simple, and enables the features of different
showers of rain to be compared at a glance, and the variations
in the size of the drops at the beginning, middle, and end of a
shower recorded. Presumably the wind must not be so high
as to blow all the flour away. It may be suggested that people
who have time to spare and wish to devote their attention to
some interesting and scientific pursuit requiring little trouble,
might do worse than form a collection of " solidified rain-
drops," and if this were done systematically by a large number
of observers scattered over the country, the observations
could not fail to afford a share of useful meteorological infor-
mation.

KNOWLEDGE & SCIENTIFIC NEWS.

[Mar., 1905.

C'mJucled by F. Shillington Scales, f.r.m.s.

Fibrous Constituents
of Paper.

(Continued from Page 42.)
The question of indeniification is much simpli-
fied if we consider first what are the fibres
we shall have to deal with. Many fibres have
been sug^yested for use in paper-making-, but
in most cases either the supply has proved insufficient,
or the cost of transport has been prohibitive,
or the " yield " of fibre after treatment has proved to
be not enough to repay the cost of such treatment and
of the transport. Therefore the fibres in g-encral use are
comparatively few, which much simplifies the matter.
They are principally as follows : — For white papers :
linen, cotton, esparto grass, straw, and chemical or
mechanical wood-pulp, and more rarely hemp and
manilla hemp ; for coarse papers : hemp, manilla hemp,
jute, straw, and chemical or mechanical wood-pulp.
It will be observed that with the exception of esparto,
straw, and wood-pulp, the paper-maker gets his
materials second-hand as rags, sacking, ropes, or
twines, when all other use for them has gone.

To show that the matter has more than a merely
academic interest, I may mention that I have
several times had papers submitted to me for micro-
scopical examination and analysis when there was a
dispute between buyer and seller as to the material of
which the paper was made, and where one party
threatened legal proceedings against the other. The
papers were sent to me simply marked A, B, C, etc.,
and I was asked, for instance, to say whether these
papers were " all rag " or not. It is satisfactory to
know that in each case I was subsequently informed
that my statement had been accepted by both parties
as correct, and an agreement arrived at, which may be
taken as shr>wing the value and accuracy of this method
of examination.

For the identification of these respective fibres a
knowledge of botany is not requisite, though it may
be u.seful. The fibres have been so mangled and torn
and twisted in the process of pulping — " beaten " is the
technical term for it, just as certain Fastern nations still
beat out the fibres with a mallet upon a stone — that
their appearance has become much altered. But the
fibres must be isolated and must be freed from all
sizing and colouring matters. This is easily done by
boiling in dilute caustic soda solution — one or two per
cent. — for a short time, then placing on a fine sieve
and washing several times with warm water, after
which they may be shaken up in a bottle with some
clean angular pebbles to further disintegrate them,
though I have generally found rubbing with the finger
on the sieve quite sufficient. Only a very small piece
of paper is required, and of this only a very tiny

amount of pulp is transferred to an ordinary micro-
scope slide. This pulp must now be carefully teased
out with needles so that each fibre stands free from
overlying or entangling fibres, and no tufts or opaque
masses are left.

The identification of the respective fibres depends on
three things, none of which, in my opinion, is it safe
to trust to alone : the structural appearance of each
fibre, its colour reaction with certain reagents, and its
behaviour w'ith polarized light. It is fortunate that
all these can be carried on without their interfering
with each other.

The microscope must be pro\idcd with an analyser
and polarizer, and it is of great ser\ice if the latter is
fitted with a screw- into which the optical part of an
ordinary condenser can be placed so as to obviate to
some extent the great loss of light due to polarization.
The objectives suitable are an inch, or, preferably, a
half-inch, and a one-sixth or one-quarter inch.

The reagents suggested have been many, of which
iodine used with dilute sulphuric acid has, perhaps,
been most serviceable in the past, but the reagent most
used now is know-n as chlor-zinc iodine, and is made as
follows, according to Stasburger's formula. Zinc is
dissolved in pure hvdro-chloric acid, and the solution
evaporated to the consistence of strong sulphuric acid
(metallic zinc being kept in it during the process). In
this is dissolved as much potassium iodide as it will
take up, and, finally, as much metallic iodine as it will
dissolve. The reagent acts much more quickly in
water or glycerine preparations than in alcohol.

The fibres having been teased out upon a slide as
already mentioned, are freed as far as possible from
water by being pressed with a piece of filter paper, a
drop or two of the reagent is added, and a cover-glass
placed over the preparation. Any excess of reagent
may be taken up with filter paper. The reaction is
almost immediate. The cover-glass is advisable not
only for convenience in examination but to reduce the
amount of reagent so that the resulting colours may
not be masked, and also because iodine volatilises and
the colours are not permanent.

(Til he ciiniimifil.)

^^^^^^

R.oya.1 Microscopica.! Society.

.\t the annual meeting held on January iS at 20>
Hanover Square (the President, Ur. Dukinfieki II. Scott.
I'.R.S., in the chair), the President alluded to the death
of Professor Abbe, of Jena, who had been an honorary
I'ellowof the Society since 1878, and said that there was
perhaps no one whose loss would be more felt by a
Society such as their own. Professor .\bbe's name was
familiar to everyone acquainted with the microscope,
and even those who were not able to follow the details of
his work would recognise the great services he had
rendered to optical science. The Secretary then read
the annual report, and the Treasurer read iiis annual
statement of accounts and balance-sheet. The result of
the ballot for the new Council was announced, the Presi-
dent being re-elected for another year, and all the other
F'ellows proposed for election on the Council being also
elected. The President then deliveted his Annual
Address, the subject being an inquiry as to " What were
the Carboniferous Ferns ? " At the commencement of
the address the President referred to the recent death of
Professor H. Renault, the well-known Paleo-botanist, who
had been elected an honorary Fellow of the Society as

Mar., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

recently as June last. The address was illustrated by
many lantern slides and by sections of fossils from the
coal-measures shown on the screen, whilst Professor
F. W. Oliver kindly lent a number of specimens, and
Mr. Smedly, F.L.S., exhibited some beautiful large scale
models.

The Quekett Microscopica.! Club.

The 419th ordinary meeting of the Club was held on
January 20 at 20, Hanover Square, the President, Dr.
E. J. Spitta, V.P.R.A.S., in the chair, The death of
Professor Ernst Abbe, who had been an honorary mem-
ber of the Club since 1879, was announced, and a motion
recording the Club's appreciation of his services to
microscopy and sympathising with his family in their
loss was unanimously adopted. Mr. C. F. Rousselet,
F.R.M.S., then gave a detailed description of his well-
known compressor, describing the various features which
he had considered essential to the object which he had in
view when designing it, viz., the examination of the
smallest living rotifers under high power objectives and
with critical illumination from modern wide-angled con-
densers. The model was completed in 1893, ^""^ had
been in use ever since with such success that he had
found no openings for alteration or improvement. The
various so-called " Improved Rousselet Compressors "
which were on the market were, in his opinion, anything
but improvements upon the original model, and he
strongly disapproved of them. The Hon. Secretary
then read a note by Mr. A. E. Merlin, F.R.M.S.,
" On the cut suctorial tubes of the Drone Fly's proboscis
as a suggested test object for medium powers." Mr.
Merlin pointed out the difficulties attaching to the use of
the Blow Fly proboscis as a test for the ^" or 1" objec-
tive, in the hands of a tyro. Formerly the Podura scale
was the most satisfactory test for such powers, but it
was difficult nowadays to obtain a slide. The Drone
Fly's proboscis was in structure similar to the Blow
Fly's, but the detail was finer.

Bausch &rvd Lomb's New Portable
Microscope.

Messrs. A. E. Staley and Co. have sent me for inspec-
tion their new " B.B.P." portable microscope. This is a
full-size microscope of the Continental type, with large
vulcanite stage, sub-stage adjustable by spiral rack and
pinion carrying condenser and iris diaphragm, coarse and
fine adjustments, draw-tube, &c. The stage is, however,

mounted on an axis, so that it, with its condenser in
place, can be swung into a vertical position, a clamp fix-
ing it when in the horizontal position, whilst the base
folds together. The microscope, with objectives and eye-
pieces, goes into a case measuring iif x 8 x 4^ inches.
This is, of course, not one of the most compact micro-
scopes, the idea being to retain all the advantages of the
full-size microscope and to add portability. The case is,
therefore, too heavy for carrying any great distance. The
instrument is beautifully finished, as are all microscopes
made by the Bausch and Lomb Optical Company ; the
objectives are excellent, and the case is exceptionally
handsome. The fine adjustment was, however, some-
what coarse in movement, whilst in the instrument sent
me the condenser did not quite focus. The tube was of
the Continental size and length, and the objectives were
marked with tube-length, numerical aperture, and power,
which I wish one could see on all objectives. There was
also an extra diaphragm immediately beneath the stage ;
but this is, I always think, an unnecessary luxury.

The Postal Microscopical Society.

A perusal of the Annual Report of this Society makes
one feel that its limited membership can only be due to
the fact that its very existence must be unknown to the
vast majority of those amateur microscopists to whom it
specially appeals. The Society was founded in 1873 by
the late Alfred Allen, of Bath, and its mode of working is
briefly as follows : Each member contributes a dozen
slides — his own make if possible ; if not, good purchased
ones. To these he adds a small notebook and notes on
the various slides. The notes may or may not be entirely
original, but they are explanatory, and there may even
be one or two drawings illustrative of certain points. If
the slides are his own mounting, he adds a few notes as
to how he mounted them, and he may also ask for infor-
mation or help on various matters from other members
who will see his slides and notes. The box of slides goes
in to the Secretary, who adds four slides from the
Society's cabinet, making 16 in all. The members are
divided up into " circuits " of seven members each, and
the boxes with their notes pass on from member to mem-
ber at intervals of six days, each member adding a few
notes to the notebook as he passes it on. When the box
has made its complete round of all the " circuits " it
returns to its owner, who keeps it, the notebook, and the
four additional slides, he himself having meanwhile, of
course, been the due recipient of all the other boxes in
due turn. This is the ideal arrangement, but it is departed
from, when members fail to send on their boxes according
to the rules, and fail to add notes and comments other
than expressions of regret for their remissness. It will
be seen that the whole scheme is simple in the extreme,
and it gives to every member an opportunity of seeing
and studying at leisure a large number of slides on very
varied subjects, of interchanging views with brother or
sister enthusiasts, and of getting assistance on thorny
points. Such a Society will, of course, appeal almost
entirely to amateur microscopists ; but to them it should
be of real service, and I would suggest that any of my
readers who are interested should write to the Hon.
Secretary, Miss Florence Phillips, 3, Green Lawn, Rock
Ferry, Cheshire, for further particulars. The subscrip-
tion is five shillings per annum, with a small entrance
fee.

[Communications and enquiries on Microscopical matters are invited,
and should be addressed to F. Shillington Scal:s, "Jersey," St.,
Barnabas Road, Cambridge.]

KNOWLEDGE & SCIENTIFIC NEWS.

[M.\K. 1905.

The Face of the Sky for March.

By \V. Shackleton, F.R.A.S.

The Sun. — On the ist the Sun rises at 6.49, and sets at
5.37 ; on the 31st he rises at 5.42, and sets at 6.28. The
Sun enters the sign of Aries at 7 a.m. on the 21st, when
Spring commences.

.\n annular eclipse of the Sun takes place on the 6th ;
it is invisible in this country, but visible in .'Vustralia.

The solar disc has been well marked with large sun-
spots, whilst prominences have been large and active.

For physical observations of the Sun the following
data may be used : —

Date.

Axis inclined from N.
point.

Equator N. of
Centre of disc.

Mar. 2 ..

12 . .

., 22 ..

21° 59' w.
24° 8' W.
25= 36' w.

7° 15'
7° 12'

6° 55'

The Zodiacal light should be looked for in the west
for a few hours after sunset.
The Moon : —

Date.

Phases.

H. M.

Mar. 6 ..
., 14 •-
,, 21 ..
.. 27 ••

• New Moon
5 First Quarter
0 Full Moon
d Last Quarter

5 19 a.m.
9 oa.m.
4 56 a.m
9 35 P-m-

Mar. 8 ..
21 ..

Apogee
Perigee

6 54 a.m.
10 48 a.m.

OccuLTATiONS. — The only bright stars occulted during
convenient hours are : —

7 Tauri (mag. 3-9) at lo.ii p.m. on the 12th.
^ Virginis (mag. 3-8) at 9.2 p.m. on the 20th.

The Planets. — Mercury is in superior conjunction
with the Sun on the loth, after which he is an evening
star, setting about 7.30 p.m. on the 23rd ; he should be
looked for in the west towards the end of the month, as
he is approaching a favourable elongation.

\'enus is the most conspicuous object in the evening
sky, being at greatest brilliancy on the 21st, when the
planet sets about 10.20 p.m. Throughout the month the
planet is well placed for observation, and is best scrutin-
ized before darkness sets in, as outstanding chromatic
aberration of the object glass is not so obtrusive. From
the point of ma.ximum brilliancy the planet appears to
move rapidly towards the Sun, inferior conjunction taking
place about a month later. About the middle of the
month the phase of the planet is crescent, 0-33 of the
disc being illuminated, the diameter lieing 35". On the
evening of the 9th, the Moon, Jupiter, and Venus all
appear in close proximity to each other.

Mars is situated in Libra, and rises about 11.20 p.m.
near the middle of the month.

Vesta the brightest of the minor planets, is in opposi-
tion to the sun on the 24th, when its magnitude is 6'3.
The asteroid is describing a retrograde path near the
star p Virginis.

Jupiter is getting more to the west and is only avail-
able for observation for a few hours after sunset, also,
on account of increasing distance from the earth, his
lustre 13 diminishing and he is altogether outrivalled in
brilliancy by Venus, which appears in the same region
of the sky.

At the beginning of the month the planet sets at
10 p.m., when the equatorial diameter is 35"'8, and on

the 31st at 8.47 p.m., his apparent equatorial diameter
then being 34""0.

The following table gives the satellite phenomena
visible in this country.

J.-

u s:

s i

2 1

B g

P.M.'s.

S g P.M.'s.

S 1 P.M.'s.

u) S

H. .M.

m 0. H. M.

m U. K. M.

Mr.

Mar.

I I, Tr. E.

7 15

I. Tr. I. 7 2

II. Oc. D. 7 10

I. Sh. E.

8 15

I. Sh. I. 7 58

I. Tr. E. 7 50

5 1 II. Tr. I.

7 17

I. Ec.R. 7 28

1°

II. Tr. E. 7 41

III. Oc. R.

7 2

II. Ec. R. 8 31

I. Tr. I. 7 39

*' Oc. D." denotes the disappearance of the Satellite behind the disc, and
' Oc. R." its re-appearance; "Tr. I." the ingress of a transit across the disc,
and "Tr. E." its egress ; " Sh. I." the ingress of a transit of the shadow across
the disc, and " Sh. E." its egress.

Saturn is a morning star, rising about 5.30 a.m. near
the middle of the month.

Uranus also does not rise till early morning through-
out the month.

Neptune is on the meridian about 7.45 p.m. on the ist,
and at 5.50 p.m. on the 31st ; he is in quadrature with
the Sun on the 26th. The planet is near m Geminorum,
and can readily be found by reference to that star.

Right Ascension. Declination.

Neptune (Mar. 15). 6^ 23™ 14^ . . N. 22° 21' 8"

fj. Geminorum . . 6'' 17™ 13'' . . N. 22° 33' 38"

Meteok Showers: —

Date.

Radiant.

Near to

Characteristics.

R.A.

Dec.

Mar. 1-4
14
24
28

h. m.
II 4

16 40
10 44

17 32

+ 4°
+ 54"
4-58°
-f 620

T Leonis
M Draconis
(SUrsseMaj.
f Draconis

Slow ; bright.
Swift
Swift
Rather swift.

Minima of Algol occur on the i8th at 0.34 a.m., and
on the 20th at 9.23 a.m.

Double Stars. — 7 Leonis, X.'' 14"% N. 20° 22', mags. 2,
4 ; separation 3"-8. In steady air, the prime requisite for
double star observations, this double may be well seen in
a3-in. telescope with an eyepiece magnifying about 30 to
the inch of aperture, but on most nights one with a
power of 40 is better.

The brighter component is of a bright orange tint,
whilst the fainter is more yellow.

t Leonis, .Xi."^ 19'", N. 11" 5', mags. 4^, 7A ; separa-
tion 2"-2. A pretty double of different coloured stars,
the brighter being yellow, the other blue. This object
requires a favourable night and a fairly high power on
small telescopes.

a Leonis (Regiilus) has a small attendant about 180"
distant, magnitude 8-5, and easily seen in a 3-inch
telescope.

a Canum Venat. (Cor Caroli), XI I.^ 52'", N. 38'^ 50',
mags. 2-5, 6-5, separation 20"; easy double, can be seen
with moderately low powers, even in 2-in. telescopes.

Cluster. — M 44, the Pra'sepe in Cancer, visible to
the naked eye as a nebulous patch, best seen and easily
resolvable with a pair of opera or field glasses. On
account of the scattered nature of the group the cluster
effect is lost when observed with a telescope unless \ery
low powers be employed. Situated about midway and
a little to the west of the line joining " and S Cancri.

KDomledge & Seientifie Hems

A MONTHLY JOURNAL OF SCIENCE.

Conducted by MAJOR B. BADEN-POWELL and E. S. GREW, M.A.

Vol. II. No. 4.

[new series.]

APRIL, 1905.

Entered at -[
Stationers' Hall J

SIXPENCE.

CONTENTS.— See Page VII.

TKe Coming Total
E^clipse.

By W. Shackletox, F.R.A.S.

In addition to registering tlie corona on the photo-
graphic plate, bright stars included in the field of view
of the lens may be recorded.

The sun will be situated in the constellation Leo,
about 8° S.E. of Regulus. The chart given below shows
the aspect of the sky at the time of the eclipse. It will be

seen that it is the same as the evening sky near the
middle of the present month about g p.m. Mercury will
appear in close proximity to the sun, being about 3^^ to
the S.W. ; the eclipse taking place only 10 hours after
inferior conjunction of the planet with the sun, thus he
will appear as a very delicate crescent. Venus is situ-
ated about 39' to the west, and is gibbous.

Observers provided with telescopes could not do better
than confine their attention to the examination of coronal
detail in the neighbourhood of prominences or near the
poles.

Quoting from the British Astronomical Association's
Report of the eclipse of igoo : " In spite of the diffusion
of photography, it may well be that in the future from
time to time an observer may find himself at a total
eclipse with a telescope, but without photographic appli-
ances. There will be still work for him to do in such a
case ; and in any case we cannot assume, until we have
both telescopic scrutiny and photographic records
throughout all the varying phases of a complete solar

A-d

3C
20"
10

izir

XVI sv

\IV XIII

-XIL JU_ JL

ix:

VIII VII

XI x:

'VUrsa

Zen

itk

3u'
10'

Jo"

40"

»Ca.st

'~'f

•/=ciiu.,

1 •/

• .

^,-oUru.s

/-.

~~^^

7
fiegii

las

£0 UA tr.r

\
\

TgO

. frocy

/ '

•

y^r.^

£'-is/'\

'S/,

• Si

r.u

/We.t

--^

afA__,^^^''''^

QZK

X7T :X3"

XIV Xlll

xn 3r X

Tx:

"VTTT "VTT

~m. :e

Aspect of the sky at the time of Eclipse (Spain). 5 Mercury. ? Venus.

KNOWLEDGE >S: SCIENTIFIC NEWS.

[April, 1905.

cycle, that the more complex and elaborate structure of
the corona at the sunspot maximum may not giveto tele-
scopic examinations greater minuteness of detail than
any but exceptional photographs can supply."

In recent eclipses the best photographs taken with the
prismatic camera show that the images of the corona in
1474 K light are not smooth rings, but rings having a
definite form not necessarily coinciding with the outline
of the corona as photographed in ordinary cameras, but
probably recording a true iiDier corona composed of the
unknown gas cnronitim. The disentanglement of this
" inner corona," or that part giving foro«/«w/ emanations
and self-luminous, from the outer corona, which is com-
posed of particles or droplets, and luminous chiefly by its
reflective power, is a difficult problem, since even in an
eclipse it is the enveloping atmosphere and not a section
of it which is presented to us. Here it seems to indicate
that advantage must be taken of the outer corona giving
a continuous spectrum, whilst the inner corona gives a
line spectrum with its principal radiation in the green,
the "corona line." If, then, a light filter be employed

rommence •

Coronal detail round p

nee. (Eclipse, 1896.)

which only allows this green light to pass through in
effective quantities, one may succeed in photographing
the inner corona alone, and thus determine the distribu-
tion of coronium in the corona. Gelatine films stained
with aniline blue and tartrazine form a light filter of this
nature ; but even this may prove insufficient by itself,
and possibly the spectroscope will have to be called in as
an additional aid. Suppose, then, a prism from an ordi-
nary spectroscope be fixed in front of the lens of the
camera, thus making a small prismatic camera which can
be accurately focussed by allowing Polaris or a bright
star like \'ega to trail and impress its spectrum on the
plate; when this is pointed to the eclipsed sun a series of
rings partially superposed will result from the radiations
of the inner corona, whilst the light of the outer corona
will be spread out as a continuous spectrum, and conse-
quently enfeebled at any one point ; hence, by the inter-
ception of a light filter as above described, one may pos-
sibly prevent all but the bright green ring from leaving
any record. Another suggestive method, which will
enable one to discriminate between these two kinds of
radiations, is to take advantage of the fact that light
reflected from particles is polarised, and thus, by
attaching a Nicol prism in front of the lens, and
making several exposures on the corona with the Nicol
at various known degrees of rotation, one may be able
to sift out the two kinds of radiations. A polariscope
opera glass, with the Nicol between the eye and the eye
lens, somewhat similar to the prismatic opera glass, would
be of service as a supplementary aid. The distribution
o{ coronium is a long-standing problem, and, quoting from
Professor Eastman's report of the total eclipse of 1878,
he says : " The limits of all the known coronal elements

should be carefully determined by measurement, at each
eclipse, and then the study of one important branch of
solar physics will rest on definite data. The existence of
the ' green line ' has been established for several years,
and it is a waste of valuable opportunity to stop at simply
saying it was seen." The spectrum of the corona requires
in general to be studied with a more powerful equipment
than that so far considered. Some observers have
reported no Fraunhofer lines in the spectrum of the outer
corona, but it would have been more surprising if they
had been seen when we learn what apparatus was
employed. It is important, therefore, to devote certain
apparatus to particular work ; negative evidence is valu-
able if obtained with suitable instruments, otherwise it
may be misleading. Ade(]uate instruments does not
necessarily mean " big," for, referring to the case above,
an observer with a powerful spectroscope would in all
probability record the absence of Fraunhofer lines, whilst
another with a less powerful piece of apparatus would
register their presence, and rightly so.

Yet another instance is the observing of certain
phenomenon in one instrument, whilst other means fail
to record it. In several eclipses observers using a slit
spectroscope have recorded the presence of bright hydro-
gen, magnesium, and iron lines in the spectrum of the
corona, and yet the prismatic camera failed to show any
of these lines. In the slit spectroscope any light falling
on the slit will be observable as images of the slit, and in
addition to the direct light from the corona and chromo-
sphere, there is a certain amount of light derived from
the same source, but diffused by particles in our atmo-
sphere, which is capable of illuminating the slit sufficiently
to be observable. Thus, the bright lines of hydrogen have
been observed to extend over the dark disc of the moon.

The prismatic camera, however, fails to register such
spurious radiations of hydrogen and calcium in the
corona, as no images of the scattered reflections can be
formed.

The recording of the flash spectrum will form an im-
portant item in the programme, both with slit and slitless
spectroscopes. It is extremely doubtful, however,
whether the spectroscope suitable for this work is also
efficient for capturing the spectrum of the corona ;
in fact, the " flash " requires both a large image and great
dispersion for its disintegration and comparison with the
Fraunhofer spectrum, whilst the corona would be more
favourably attacked with a small image and high disper-
sion, in order that the lines or rings may be intense,
whilst the continuous spectrum is either resolved or
so enfeebled that the lines are exhibited in better
contrast.

The "shadow bands" are a subsidiary phenomenon,
and on this account they have usually been neglected or
treated in an unscientific manner; thus we read that their
progress was at the rate " of a trotting horse," and
observations have usually been confined to one plane.
It seems important to gain more definite information
about them, whether they are due to scintillatory effects
of the atmosphere, in which case wind direction may be
important ; or, what is more doubtful, are they some
difl'raction effect ? Whatever be the true explanation,
it seems necessary to observe them on two planes at
right angles to one another, whence the plane in which
they lie, or its normal, may be ascertained, and its
reference to the sun or the cusps may be determined.
Observation should also be made to see if they persist
during totality, and especially should they be looked
for at any stations of high altitude to note the effect of
diminished atmosphere.

If their movement be too great for accurate eye esti-

April, 1905.

KNOWLEDGE & SCIENTIFIC NEWS.

mation over a known length, observation might be made
by intermittent vision, say by rotating sectors, and thus
determine when they appear at rest.

Observers will be stationed at various points of vantage
along the belt of totality, and arrangements have been
made for the following British observers to occupy the
places named :- —

Spain.

Mr. J. Eversbed Burgos.

Kev. A. L. Cortie, S.J Tortosa.

Prof. Callendar \

Prof. Fowler - Oropesa.

Mr. Shackleton I

Majorca.
Mr. Crommelin Palma.

Algeria.

Sir Norman Lockyer ]

Dr. Lockyer - Philippeville.

Mr. Butler I

Mr. Newall Bona.

Tunis.
Sir William Christie (The Astro-i

nomer- Royal) ' c^^^

Mr. Dyson "

Mr. Davidson )

Egytt.

Prof. Turner |

Mr. Bellamy I

In addition to the above, American parties will
observe from Canada, Spain, and Egypt, whilst three
French astronomical parties have selected Burgos,
Tortosa, and the Mediterranean coast, and two others
intend to observe it from Sfax and Philippeville, Algeria.

It is to be hoped that the weather will be propitious,
and that observers may obtain good results all along the
line.

Eclipse, as visible in London.

In London the eclipse will be visible as a partial one,
8-ioths of the sun's diameter being obscured ; the dia-
gram'given above exhibits the appearance at maximum
phase, which takes place at 1.5 p.m., on August 30.

With 73 per cent, of the light cut off, it should be
possible to make observation of the remaining chromo-
spheric arc to a greater depth than is usually done in full
sunlight, and observers remaining at home would be
doing useful work in measuring the depth visible, or in
searching for the corona line at x 5303.

It is too much to hope that the corona itself can be
recorded, but it would be well worth trying to photo-
graph the dark moon beyond the limb of the sun, for
both Mercury and Venus have been visible as black
discs, just before transit, signifying a background of
sensible brightness compared with the aerial illumi-
nation.

Na-tural Ga.s irv America.

.'\ccoRDiNG to the annual report of the United States Geo-
logical Survey, the natural gas industry in the United
.States, so far from decreasing, has shown in the last re-
ported year a considerable increase. .A.ccording to the last
report of the United States Geological Survey its value in
1903 increased from ;/76,ooo,ooo to ;/77,ooo,ooo (not dollars) ;
and there was a remarkable increase of production in
Pennsylvania and Ohio. West Virginia and Indiana were
the other two States in which natural gas production was
of any importance, and Indiana is the only one of them
recording decreased production. The general average of
the price paid by the consumer increased slightly, and was
about 75d. per 1,000 cubic feet at a pressure of a quarter of
a pound to the square inch. The increase in the use and
consumption of natural gas in the States is no doubt to be
attributed to legislative restrictions with regard to boring ;
and to improved pumping machinery. The prodigal waste
which characterised the early discovery of natural gas —
when people used to use it almost as a plaything — has
ceased, and new borings can be made only under State
supervision. There seems no reason to suppose that any
new areas of great extent will be found ; the gas-bearing
strata are now fairly well defined, and their possibilities
ascertained.

It is not a little remarkable that side by side with the
increased use and value of natural gas, the output of
petroleum should also be on the increase. .According to
Mr. F. H. Oliphant, of the United States Geological
Survey, the total production of crude petroleum in the
United States in 1903 was 100,461,337 barrels, a gain of
11,694,421 barrels, or 13.17 per cent, over the production of
1902. The great increase was mainly due to the remark-
able output in California, which is now larger than that of
any other State. California produced 24.27 per cent., or
nearly one-fourth of the entire production. Next to Cali-
fornia the largest gain in production was in Indiana, which
was 1,705,515 barrels, an amount that represents a gain of
22. So per cent, over the State's production in 1902. Kansas
showed a remarkable gain in production — 600,465 barrels,
or iSi per cent.; Kentucky and Louisiana showed" gains of
about 369,000 barrels each; Indian Territory gained 101,811
barrels, or 274.4 P^"" cent.; and New York "gained 43,248
barrels, or 3.86 per cent. On the other hand, there was a
slight decrease of production, 128,086 barrels, or 0.70S per
cent., in Texas ; and Ohio, Pennsylvania, and West Virginia
all showed decreased production, amounting to a total of
1,856,619 barrels, or 3.98 per cent., in 1903 as compared
with 1902. The largest decrease in production in 1903 was
in Pennsylvania, and amounted to 708,724 barrels. During
the last six years there has been a very remarkable change
in the percentage of the local production. The .Appalachian
and the Lima-Indiana fields, which for many years pro-
duced all but a very small percentage of the' whole, pro-
duced in the year 1903 only 55.38 per cent, of the total,
whereas in 189S these fields produced 93.99 per cent, of the
total. California and Texas have been the most important
factors in bringing about the readjustment of the percent-
ages of production.

KNOWLEDGE & SCIENTIFIC NEWS.

[April, 1905.

"Ad Infinitunv.'

The Structvire of the Atom.

By Beresford Ingram, B.A. (Cantab.), F.C.S.
Prof. J. J. Thomson's lecture at the Royal Institution
on March 10 on " The Structure of an Atom " must
have been bewildering to an extreme to all those who
are not acquainted with the most recent developments
of science.

To many of us an " atom " conveys but a very vagfue
idea. We think of it as something smaller than one of
those fine dust particles we see floating about in air
when a beam of sun-light enters a room. We are told
it has weight, but at the same time we are instructed
that we have no means of weighing it. A rea.sonable
conception of its size can be gained by imagining an
ordinary drop of water to be magnified to the size of
the earth, then the particles composing the drop would
be the size of cricket balls.

Chemistry has taught us how these particles arrange
and behave themselves one to another, but physics
goes further than that, and proposes to show us of what
and how these particles are made up.

Over ten j'cars ago Prof. Thomson proved that one
of these a/cms* of hydrogen is composed of one
thousand smaller particles. ' All these particles or
" corpuscles " have the same mass, and are similarly
charged with negative electricity.

If this be so, then they must all repel one another.
This fact compelled the physicist to consider all these
particles being held together by a positive charge of
electricity, an assumption which, to some extent, was
warrantable by reason of the fact that positive elec-
tricity is always found associated with large masses of
mntter.

Thus the simplest form of matter that can be
imagined is one of these negatively-charged corpuscles
being surrounded by a sphere of positive electrification.

Before anything further can be known about the
atom we must find out how these corpuscles arrange
themselves when there is more than one in the atom.

This is, to .some extent, experimentally demonstrated
by taking some short thin rods of steel and magnetis-
ing them. They are then stuck through corks, and so
arranged that when placed in water they will float
perpendicularly with their north poles uppermost out of
the water. In this way the magnets can move in one
plane only, i.e., that of the surface of the water; but it
must be borne in mind that the corpuscles composing
an atom are assumed to be free to move in any direc-
tion.

When two such magnets are placed in water they, nf
course, assume some position apart from one another;
three form an equilateral triangle; four form a square,
five form a circle with the magnets at equal distances
from one another, six form a circle with one in the
middle.

The following list shows how the magnets would
arrange themselves when thrown indescriminately into
the water, from which we conclude that such is their
position or arrangement of equilibrium.
No. of magnets 5, 7, 8, 9,
Outer ring . . 5, 6, 7. 8,
Innijlf^ing .. o, i, i, i,

* An atom is defined as the smallest quantity of an element
which can enter into combination with any other element.

. II,

13.

19.

23.

30,

.ir..

■272

. 9.

10,

12.

13.

I.?.

16.

. 40

I 2i

10,

i5(

20.

•232

The arrangement is found to be more stable, the
greater the number of magnets within the inner ring.

Supposing an atom to contain twenty such particles,
then from the above table we could find out how they
arranged themselves. Look along the first line of
numbers and select the one nearest to twenty; it is
nineteen. This, as is observed, arranges itself twelve in
the outer ring and seven in the inner; there is still one
corpuscle over which would go within the inner ring
and increase the stability of the atom. Similarly, an
atom with 21 corpuscles would have twelve in the outer,
seven in the inner, and two in the inmost, and would
be even more stable than the atom with twenty
corpuscles. Twenty-two corpuscles would make a
more stable atom still. When, however, we get to
twenty-three corpuscles a new arrangement takes place
in which we get two rings only — thirteen in the outer
and ten in the inner. .As the number increases from
twenty-three to thirty, we get a whole series of bodies
with increasing stability (since the extra corpuscles arc
entering the area of the inner ring) until we come to
thirty, when we suddenly get another arrangement.

But this is exactly what we get in the periodic classi-
fication of elements. .Starting with lithium, and taking
the elements in order, as their atomic weights increase,
we find we go from elements of marked electro-positive
nature to those of decided electro-negative, then
suddenly it reverts to an electro-positive element
and the gradation to the negative clement starts all
over again.

Thus sodium, which marks the sudden reversion
from electro-negative to electro-positive elements, may
be considered as containing the arrangement necessary
to give lithium its electro-positive properties with
another ring (arrangement) or rings, that have no odd
corpuscles, added on to it. If, by any means, hereafter
to be discovered, the atom of sodium could be robbed
of its extra ring or rings, as a whole, we should expect
the transmutation of sodium to lithium to have been
effected.

-So much, then, for the arrangement of the corpuscles
forming the atom; now let us turn our attention to the
behaviour of the atom itself.

Even a superficial knowledge of chemistry would be
enough to force upon us the conviction that there
exists some constant law controlling the mo\cments of
the atoms composing an element.

A study of the following experiment will show very
clearly that the atom does not obey any of the exi.sting
laws which are known to control matter.
Three electro - magnets are placed' as in figure,
/ with their nortii

poles pointing to-
wards a centre.
Between the an-
gles so formed
are placed three
vessels of water
which allow one
magnet to fioat
perpendicularly in
each, north pole
uppermost. The
magnets are so
arranged by guid-
ing wire that
they can only
move along a line which bisects the angles
between the magnets. Imagine, for the sake of illus-
tration, that the electro-magnets in the centre form a

April, 1905.

KNOWLEDGE & SCIENTIFIC NEWS.

nitrogen atom, and that the magnets in the water are
hydrogen atoms.

N'ow switch on the current and observe the floating
magnets; they all approach the " nitrogen atom " up to
a certain distance and no further. The movement is
very decided at first, but slows down gradually up to
the said point. Move the " nitrogen atom " round so
that the movable magnets (" hydrogen atoms ") are
in a direct line with the electro-magnets and the move-
ments of the former obey the ordinary laws of magnetic
repulsion.

The experiment seems to point out that the condi-
tion essential to stability in chemical combination is
that " the attraction of one atom to another (or others)
increases as the distance increases." It is thus the
opposite to the law of inverse squares.

It would also seem to show that combination is only
effected when the atoms have taken up a definite posi-
tion one with another.

We may suppose an atom to have around it certain
regions which are habitable by other atoms, and when
the former are occupied by the latter a stable body
results.

This would harmonise with our ideas of valency and
make the suggestion reasonable, that an element may
be polyvalent, since it is supposed to have so many
" valency regions " which may or may not be occupied
by other atoms.

A carbon atom is said to have four such valency
regions. If, now, two carbon atoms are brought to-
gether in such a way that one valency region of one
carbon atom comes into intimate contact or coincides
with one valency region of the other carbon atom, then
the region referred to is rendered uninhabitable; the
two carbon atoms are held together by a force which
obeys the law enunciated above, and we get a ready
and adequate conception of the constitution of ethane
C, H,;. Similarly when two " valency regions " of
the carbon atoms coincide we get the constitution of
ethylene C2 H4, and when three (since the regions must
not be supposed to be in one plane), we get the con-
stitution of acetylene C2 H2.

So little is known about the properties of electricity
that it may be doubted whether the atoms are, indeed,
electrified; but apart from the mathematical calcula-
tions based on that assumption, which confirm all the
known facts, there are other sources from which evi-
dence can be drawn, one of which is especially worthy
of attention : —

" Solutions of certain compounds are observed
to rotate the plane of polarization."

If atoms are charged, the explanation of this
phenomenon is simple and straightforward. If, how-
ever, the assumption is rejected, the explanation be-
comes complex and unsatisfactory.

For many years the scientific world has been satisfied
with its conception of the atom as first taught by
Democritus and afterwards strengthened by Dalton as
a result of his quantitative experiments.

This conception successfully grappled any difficulty
that could not be explained except by assuming that
the atom was a small indivisiljle particle.

It is only comparatively recent research in physics
that has demanded its sub-division, and although this
does not effect its definition as far as the chemist is
concerned, yet others may ask " Can this corpuscle be
divided? " Shall we hear some physicist in later years
expatiating on the structure of this corpuscle, or shall
we be told that now we are as far as we can go, since
the corpuscle is the smallest mass conceivable?

How Britain, becscme
IsldLiid.

By Edward A. Martin, f.g.s.
Author oj "A Bibliography of Gilbert White,' &-c.

There are few phenomena which appeal to the
imagination so vividly, and bring to mind the solid
geological fact that what is now land was not always
dry land, and that where now rolls the open sea was
not always covered by the waters of the ocean, than
what is known to sea-faring men as the Dogger Bank.

As a geologist, one is frequently being asked
whether it is a fact that this or that place in which
the questioner happens to be interested for the time
being was at one time beneath the sea. Those who
have not grasped the great geological truth that the
level of the land-surface has constantly changed in
the past, and even now, in many parts of the world,
\i undergoing either subsidence or elevation, fre-
quently express considerable surprise when they learn
that the earth's crust is continually subject to vertical
movements; and greater surprise still is shown when
it flashes upon them as a geological fact, that Great
Britain was not always an island; and that since the
time that our country was inhabited by mankind, it
had a continental existence, being, in fact, but a
portion of a north-western extension of the continent
of Europe.

Although, at a later period in its history, England
formed a peninsula which was connected with Europe
only by a narrow neck where now are the Straits of
Dover, yet, at still earlier time, we have ample evidence
to show that Ireland was joined to Great IBritain, and
the latter to Denmark and Scandinavia. Tliis could,
of course, only be so when all those now isolated coun-
tries formed portions of a vast plateau, when the sea-
board was at some considerable distance from the
present coast, and the whole was at a much greater
elevation above the sea than now.

It is a well-known fact to mariners that when they
pass out of the English Channel into the Atlantic, in
a comparatively short distance they pass from shallow
depths to those which are ten times as great. The
same experience is gained in going west from any
point on our west coasts, and also in a northerly
direction from the north of Scotland. But it is very
different on our eastern coasts. With exception of
a narrow strip off the Norway coast, which would ap-
pear to have been at one time the bed of a rapidly-
flowing river with considerable power of excavation,
the whole of the North Sea is shallow, as compared
with the depths found in other seas of the same mag-
nitude.

If we look at one of the hydrographical maps of the
Admiralty, we shall see that the hundred-fathom
line is found some little distance beyond the north of
Scotland, and that thence it proceeds in an easterly
direction almost to the coast of Norway, leaving the
North Sea to the south of it, and all of that sea en-
closed within that line is under 100 fathoms, or six
hundred feet deep. This is a very shallow depth for a
sea of the size of the North Sea.

Now follow the same loo-fathom line around_our
west coasts, and we find that it proceeds some consider-
able distance bevond the outermost of the Hebrides,

KNOWLEDGE cV SCIENTIFIC NEWS.

[April, 1905.

when it turns south, so as to include within it the whole
of Ireland. Then, following the same line still further
south, it is found off the entrance to the English
Channel, when, crossing the Bay of Biscay, it reaches
very near to the coast of Spain. It is when we pass
beyond the limits of this line that we find a compara-
tively rapid descent into oceanic depths. In fact, it
roughly represents the coast-line of the plateau-like
extension on which the British Isles stand, and is in
itself evidence of a great probabilitv that up to that
limit what is now the bed of the ocean was once dry
land.

The changes which have since taken place form a
history of extreme interest, but it must be borne in
mind that great though the changes were, they were
extremely gradual in their accomplishment. After the
great plunge which had visited these islands in the
middle of what is known as the Ice Age. the area of
the North Sea had become a mass of ice, and this,
travelling westwards from the heights of Scandinavia,
had turned aside the numerous smaller masses of
moving ice which had been given birth to by the
Scottish mountains, and the heights of the Pennines
andWales. The result was that such parts of our higher
lands which were above the sea-level were submerged
beneath ihe ice-sheet, and the whole country must have
presented an appearance not unlike fireenland of the
present day. Possibly here and there the highest
points of our mountains projected through snow and
ice, forming prominences, or "nunataks," similar to
those seen by Nansen when crossing Greenland. But
at the height of the glacial period, probably even these
were covered, and right away from an elevated Scan-
dinavia the ice slowly moved westwards, and, over-
flowing our islands, passed on to break up into ice-
bergs in the ocean to the west and south-west.

The submergence of the islands lasted, humanly
speaking, for a long period of years. From a geo-
logical point of view it lasted long enough to allow of
the formation upon the glacier-formed boulder-clay
of certain shell-bearing gravels; but as these are now
at heights of 1,800 or 2,000 feet above the sea-level,
there has apparently been, since these inter-glacial
days, an uprise of the land to that extent. Such shell-
beds are found near Macclesfield, at Moel Tryfaen,
and on the shores of the Clyde.

We are here therefore presented with the fact that
an enormous elevation of the land took place, and that
this happened after both sea, and what little land there
was left, had been submerged beneath the great ice-
sheet.

Apparently by this time a decline had set in so far
as the severity of the climate was concerned. The
glaciers in our own mountain regions commenced to
reassert themselves, this being only possible when the
Scandinavian intruder commenced to retire. There
was no longer a sea of ice. Switzerland or the Hima-
layas would give us a truer picture of our country at
this time, when the glacial conditions were on the
wane.

.Many of the boulders which are now scattered about
far from their place of birth may have taken their
journeys at this time; or those that had journeyefl
during the period of the first formed boulder-clay
may now again have been taken up by the recurring
glaciers, and sentenced to retransportation. The great
lumps of shap granite that one sees at Robin Hood's
Bay and at Heyburn Wyke, or in the churchyard at
Orosmont, may have been brought to rest now, far

from the home of their birth in the Westmoreland
Hills.

The re-elevation of the land must have had marked
effect upon the coast-line. Probably the movement
went on until the coast was thrown outward to the
loo-fathom line, and our country was but a central
portion of the great plateau then exposed. There was
no English Channel left, and hence the Channel Islands
and our own Isle of Wight were continentally con-
nected. The Bristol Channel was non-existent. There
was no St. George's Channel between Ireland and
Great Britain. The Hebrides, the Shetlands, and
Orkneys were all part of the land-mass, and the North
Sea was non-existent.

In the centre of the North Sea there was at this time
an area of about 300 square miles, which was con-
siderablv higher than the surrounding North Sea Plain.
This was situated some 100 miles off our present
Northumbrian and Yorkshire coasts, and what is now
left of it beneath the sea is the famous Dogger Bank.

On the whole, this plain must have been a wide, dull,
and uninteresting flat extent of land, but although it
had but few heights, it was eminently suitable to be
the habitat of herds of wild animals. For, in the
course of time, the ice passed away completely, forests
grew upon the land, with pasturage suitable for the
vegetarian livers who swarmed upon it. This was at
the time when the British elephant was in his prime.
I lerds of bisons roamed over it. Crowds of reindeer
and Irish elks added picturesqueness to the landscape.
And in the waters and rivers the woolly rhinoceros
and the hippopotamus disported themselves.

But what of the rivers which watered the land ?
Where did the rivers of Germany turn to in order to
find an exit into the sea? Where went our Thames,
our Severn, and our southward-flowing rivers?

There being no English Channel, a river which rose
in the submerged \\'ealden area between Hastings and
the French coast no doubt passed westward to the
ocean, receiving on its way as tributaries the rivers on
the French and English coasts. The Severn and a
river from the Irish Sea may have joined to form
another such river, and this may have also joined the
Channel stream. Our Neolithic progenitors, in coming
to us from the Continent, would have had to cross this
river, but with the many monuments which they have
left of their civilisation this would not probably have
caused them any dilliculty. For the greater part their
journey would have been on dry land.

The German rivers no df)ubt excavated their own
valleys across the plain and emptied thcmsehes into
the northern ocean.

But what became of the great Rhine? As it now
emerges into the sea, it seems to point to the west.
But it could scarcely have continued in that direction,
for the parallel ranges of chalk downs were then
existent between the luiglish and French coasts, and
these would be sufficient to turn the river northwards.
There is little doubt, in fact, that it travelled north,
some little distance off our British coasts, and that the
Thames and all our eastward-flowing rivers formed
tributaries on its left bank. Some of the most im-
portant fishing grounds now seem to be in the valleys
scooped out by this long-ago greatly-extended Rhine.

This condition of iiffairs did not last long in geologi-
cal time. The sea had for some time been creeping
up the English Channel and forming raised beaches at
Freshwater, Brightr)n, and elsewhere, and, when Scot-
land and Northern England began to sink, together
with the North .Sea Plain, the sea began to encroach

April,

1905.

KNOWLEDGE & SCIENTIFIC NEWS.

upon its former dominions. The animals retreated
farther and farther south, until many of them took
lefuge upon the high land of the Dogger Bank. This,
in the course of time, became an island, the sea soon
enclosing it on every side. In the trawling operations
which are constantly going on in the region of the
Dogger, many bones and teeth of the mammoth and
other animals now- extinct in those regions are con-
stantlv being brought up. In fact, scarcely a trawl is
brought to the surface that does not contain some of
these remains. Now why should they be found there
in such abundance? Probably the various currents
which were brought into play as the surrounding parts
came to the surface may have been responsible for
banking up hereon many of the bones, &'c., collected
from the area which was sinking into the sea. But
there seems also good reason to believe that the Dogger

Island formed a veritable place of refuge, where were
congregated during the last years of its existence the
numerous animals who had been driven south, who
had here been stranded involuntarily while the ad-
vancing sea cut off their retreat. Betw-een the time
of its having become an island and its own final dis-
appearance beneath the ocean, not many thousands of
years may have elapsed. There would be no time for
the evolution of fresh species. Those that were first
here isolated were of the same kind as those who w^ere
finally starved out, or overwhelmed in the advancing
waters. There in the end they succumbed, and their
remains are now- brought up in the North Sea trawling
nets.

We can pursue the evolution of the British Isles a step
further. Britain had by this time received its comple-
ment of Neolithic savages, whilst Palaeolithic man,
who had seen the advent and disappearance of the great
ice age, had also disappeared before the march of the
more civilised Neolithic man. Owing to the absence
of true glacial formations in England south of the
Thames, it is considered that these parts at no time
were the nursery grounds of glaciers, and that they did
not participate in that great subsidence which visited
all those parts which were subjected to the enormous
weight of the great ice-sheet. The North Downs were

all the while continuous from the Forelands and from
Folkestone to the Continent, as w-ell as the South
Downs from Beachy Head, and the intermediate
Wealden Heights from the neighbourhood of Hastings.

When the sinking took place in the bed of the
English Channel, which allowed of the approach of the
sea, the action of the waves, aided to an important
extent by tide action, soon widened the Channel by
eating away the soft tertiary strata which probably
covered the chalk. Then attacking the chalk it formed
cliffs of this rock, and the work proceeded until the
sea had encroached to a point east of Brighton on the
British coast, and a corresponding position on the
French coast. Here was a pause, to which are to be
attributed the raised beaches, which rest upon ledges
in the chalk, w-ith the old chalk cliffs behind them.

But soon the pause came to an end. The sea again
advanced, and cut through the beaches it had formed
at the eastern end of the English gulf. Thus was lost
the connecting sea-margin between England and
France. Probably this eastern shore was pierced at
more than one place by short rivers, w-hich were then
draining the Wealden saddle-back ridge which formed
the backbone of the Anglo-French isthmus. Others
may have flowed in the opposite direction and have
been at one time part of the great Rhine system. Simi-
lar ri\-ers piercing our present chalk downs and taking
their rise in the Weald are seen in the Sussex Ouse,
the .-\run, and .Adur; in the Mole, the Wey, and the
Darent; but in these days thev were powerful rivers,
and flowed from a greater height than now.

The advancing sea w-ould creep up the beds of these
imaginary rivers, widening their valleys as it advanced.
Soon it would reach the low parts of the Weald clay
between the two parallel ridges of chalk downs, and
the English Gulf and the North Sea would join hands
by the connection provided by the river valleys. Thus
the chalk hills would be attacked in the rear, and in
the course of a short geological period the chalk
isthmus would be gradually planed down, and the
incipient Strait of Dover become an accomplished fact.
Once the passage had been made for the tides, the
breach would quickly widen, and the isolation of
Britain thus became assured.

The position gained has been maintained. Britain
an island had been the end to which geological agencies
had been moving for many thousands of years. Now-
the end was gained. Britain an island had become an
accomplished fact, and in spite of numerous sub-
sequent minor movements she has retained that posi-
tion w-hich Nature gave her — an island set in the silver
sea.

Absorption of Mercury Va.pour by
Aluminium.

M. Tarigi has recently been investigatins the power which
alumiQium has for absorbins; mercury vapour. This is mani-
fest even when the vapour is largely diluted with air. and at
the temperature of the surrounding atmosphere. This pro-
perty constitutes a very delicate method of analysing the
presence of mercury, and furnishes a means of prevention
against poisoning by its vapours. .A respirator has been con-
structed in which the air, before entering the lungs, has to
pass through a mass of finely-pulverised aluminium, and in
this way all traces of mercury are absorbed so completely that
breathing can be carried on even in the dense vapours pro-
duced by the burning of chloride of mercury.

KNOWLEDGE & SCIENTIFIC NEWS.

[April, 1905.

MonocleoL Forsteri.

By Leo Farmar.

This little plant is a glorified relative of the Common
Liverwort, which is so frequently seen growing on the
soil of pots in conservatories.

The genus Monoclea is an interesting exemplification
of the evolution of types, forming as it does a connecting
link between the liverworts proper (Marchantiaceae)
and the scale mosses (Jungermanniace;c).

It has always been a matter of contention as to which
section it belongs, some botanists placing it in the one
while others placed it in the other group.

Professor Duncan S. Johnson, of the Hopkins
University, U.S. .A., has recently investigated and been
able to throw additional light on the subject,* showing
beyond doubt that the hepatic plant in question belongs
to the order of Marchantiaceae.

.Moncclej I-orsteri. Hooker.

Among other important characters, Professor John-
son has discovered that some of the rhizoids, or one-
celled roots, ha\e minute tubercles on the inner surface
i»f their cell wall, just as in the Liverworts proper.
These tuberculatc rhizoids have been overlooked by
earlier observers, probably because of their comparative
rarity.

The conclusions arrived at are: "That the thallus
(the plate-like vegetative portion) of Monoclea is like
that of the Marchantiacea in gross structure, in the
mode of growth and branching, in the type of initial
cell, and ... in the possession of tuberculatc rhizoids,
as well as thin-walled ones, in which latter character
Monoclea differs from all described Junger-
manniacese."

He further adds that " the facts of vegetative struc-
ture referred to strongly indicate a relationship with
the Marchantiacea- and the structure and develop-
ment of the reproductive organs seem to me to con-
firm this beyond reasonable doubt."

Monoclea occurs in Jamaica chiefly on wet rocks and
banks in the mountain forests. It may be seen grow-
ing most luxuriantly in some of the small depressions
near \ew Haven Gap in the Blue Mountains. It is
distributed also in New Zealand and Patagonia, and
was first brought home by a naturalist who accom-
panied Captain Cook on his famous voyage.

The annexed photograph is of a specimen cultivated
in the Physic Garden at Chelsea. It is a beautiful
object, its delicate dark-green crisp and crested foliage
makes it worthy of a place among the choicest of tropi-
cal plants.

The Unfolding of tKe Wings of

Insects Emerging fron\ the

Pupa.e State*

Jiy The Kev. Arthur East.

XoT the least astonishing detail of the marvellous
change from a mummified chrysalis, or an unsightly
nymph into a winged insect of more or less surp.issing
beaut)', is the manner in which the wings unfold.
Looking at the small size of the wing cases in the
chrysalis, and contrasting these with the comparatively
enormous wings of the perfect insect, it seems im-
possible that these wings should have been folded into
so small a space.

•"Ihe Development and Relationship of Monoclea.
S Johnson. Dolaniial Gazeltt, SeplemSer. 1904.

Fig. I.— Crumpled appearance of the wings upon cmerKcnce from
the nymph skin.

The process of unfolding is most easily studied in
the case of clear-winged insects, as when the wings
are clothed with scales the effects, to which the pre-
sent article is intended to draw attention, are marked.
I'robably one of the best examples is one of the larger
dragon-flies, as the wings are excessively large, and
the body, being also bare of .scales, shows clearly the
part which it plays in the unfolding of the wings.

Fig. I shows the appearance of the wings of the great
green dragon-fly/lisrhna Cyanea, when emerging from
the nymph skin — little more than a lump of damp,
crumpled wing material, greyish in colour, ;m(l (|uitc
opaque ; yet in three hours these insignificant
excrescences have to expand to wings considerably
longer than the body, and to become perfectly flat and
transparent.

April,

1905,

KNOWLEDGE & SCIENTIFIC NEWS.

How is the unfolding done? It might be supposed, | shown by the fact that if the wing is injured at this
from the fact that such a large number of the heavier stage large drops of emerald green fluid are extruded,
insects climb up some support and let the wings hang An instance'of this came under my notice ; this particular

..sect hanging erect, the
beginning to unfold.

Fig- 3— The wings unrdding, the abdo
strongly bowed and much distended.

Fi2.4.— The wings unfolding, the abdomen
strongly bowed and much distended.

down as they expand, that the weight of the wings
alone would account for the unfolding; this, no doubt,
is a considerable help, but it is not sufficient to account
for the perfect flatness ultimately obtained, and, more-
over, it takes no account of those winged insects which
do not hang themselves up, the common gnat, for
instance.

We may reject, I think, the notion that air is in-
jected, as that would probably cause a certain " puffi-
ness " in the wing, of which there is no sign. I hope
to show that the expansion of the wing is effected, in
one instance at least, by the injection of fluid, and thus
it is a spontaneous action, and entirely under the
control of the insect itself.

Now, in the case of the dragon-fly illustrated, the
insect, on emerging, hangs head downwards for some
little time, for twenty minutes or more ; during that
time there is not the smallest tendency of the wings to
unlold, but directly the second stage of emergence is
reached and the insect hangs right way up, the wings
begin to unfold at once ; careful observation will show,
moreover, that the unfolding is not continuous nor
regular as if the creases were simply falling out, but
is by fits and starts, and that these irregular movements
correspond exactly with great muscular efforts, the
segments of the abdomen are contracted, and the im-
pression given is that of someone taking a deep breath
and exerting great force. Occasionally there are
spasmodic jerks and quiverings, as if to' shake loose
the folds of the wings. All this time the abdomen is
strongly bowed to the exact curve to be occupied by
the wing, no doubt to avoid injurv to the excessively
tender fabric of the wing. It is scarcely possible to
doubt that the wings are being forced out of their
folds by the muscular energy of the insect.

And that it is fluid which is injected seems to be

Fig. s.-The abdomen straight, wings nearly dry.

insect was injured by a grass stem, and the wing did not
recover, it remained crumpled and was a complete
failure.

KNOWLEDGE cS: SCIENTIFIC NEWS,

[ArRii., 1905.

An interesting question remains as to what becomes
of this fluid, for at a later stage the wings are per-
fectly dry. Some of it probably escapes through the
pores of the wing, but I am inclined to think that the
greater part is withdrawn into the abdomen by an
action the reverse of that by which it was injected.

For hours after the wings are perfectly flat and dry
the abdomen is greatly distended throughout its whole
length, and at intervals during the first day after
emergence, fluid is ejected, a drop or two at a time,
from the rectum. This fluid is perfectly colourless, the
green colouring matter being retained in the body of
the insect (in this case of ^Eschna Cyanea or green
insect). And not for several days does the abdomen
become dry and quill-like as when we see the insect
on the wing.

Forecasting Seasons.

To THE Editors of " Knowledge."
Sirs, — While there are many weather prophets, we seem to
have at present little or no sound knowledge as to the character
of future seasons, though the cyclical nature of much of our
weather, on which fresh light is being thrown, gives reason to
hope that this important art of long-range forecasting will one
day be achieved, in some measure.

I have lately met with a case in which, I think, one could
feel something like certainty regarding a forecast of distant
weather ; and a forecast sufficiently definite to be useful.
The subject is that of the number of frost days at Greenwich
in the latter half of 1904 (the average in that half being
about 18).

J ISvi '6 'so 'h 'g ^^•^ '6 '7° '•' 'S 'y^ '6 ''?'» '^ 9 oa fiPl,

For such inquiries I have been making use o( lii'iccsmoolliid
curves. Thus in the present case, the series of numbers of
frost days in the latter half, from 1841, is first smoothed in
sums of five (grouping 1841-45, '42-'46, and so on). Then
these sums are smoothed in the same way. The sum in each
case is put opposite the middle member of the group.

The series thus obtained yields the lower curve of the
diagram. The upper curve is got in the same way from the
numbers of frost days in the earlier half of the year (average 37).
Above are indicated the years of maximum and minimum sun-
spots (without regard to numerical relations), the influence
of which, I believe, comes out in these curves ; but without
entering into this question, or considering how this double
smoothing affects the truth of Nature, I would merely call
attention to the continuous up and down course of the curves —
the rise for several years from the lowest points, and fall for
several years from the highest.

The lower curve, ending in 1899, is derived from the actual
series ending in 1903. Now, in prospect of the latter half of
19<J4, we might ask, What will the curve do next, go up or
down ? Few. probably, would hesitate to say, go up. Then
how much will it go up ? Here it often seems difficult to form

a right conjecture. But in the present case it so happens that
a rise of only i, that is, an addition of one day to the figure for
iSgg, means that the actual number of frost days for 1904
would be in excess of the average (over
figures from 1S90 to make this clear :

1S90

1891

(-)

ib)

189S

1S99

(<')

I J

. 18

(*)

t'3

314

320

1892

1S93
14
75

1901

1894
II
79
374
1902

1S95

65
348
1933

1 will give the
1896

61
330
1904

(20)

1S97
8
68
314

1900

3 24 10

65 67 (6g)

()20
(a) Actual numbers. (/') First smoothing, (c) Se-ond smoathing.
The figures in brackets are those for an addition of i to the
curve-value of uSgg, giving the value 20 for (ii) in 1904; 2 above
average.
The actual number proves to be 23 ; 5 above average.
One could thus safely predict a cold last quarter (frost days
over average), and might even estimate the amount of excess
approximately.

Doubtless other cases equally clear may be met with.
I am, yours, &c.,

Alex. B. MacDowall.
g, Saltwood Gardens, Ilythe.

Wireless Telegraphy.

Those particulars that have been made public of the opera-
lions of wireless telegraphy in the Russo-Japanese war have
amply served to endorse the soundness of the official view
that all the wireless tele{;raphic installations of a country
should be licensed and known, so that in case of war they
could be immediately brought under Governmental supervision
and control. We are in a position to say that the Government
Wireless Telegraphy Bill, which was at first vigorously con-
demned by more than one electrical engineer as likely to
hamper and stiHe enttrprise, has been found in practice to do
nothing of the kind, and is now acclaimed by some who were
at first its opponents. Tlie Act is being administered in a
broad-minded spirit, and it has been recognised that it
operates for the convenience of investigators. " Before the
Act," Professor J. A. Fleming has recently said, " we were in
the position of a number of people at a public meeting who
might by all speaking at once prevent anyone from being
heard. The Act regulates and distinguishes our utterances,"
which is another way of saying that as yet wireless telegraphy
has not yet reached the stage when it is secure against violent
" interference " from conflicting stations. The same is true
in a less degree of ordinary telegraphy along wires, which
might be upset by anyone rich enough or malicious enough to
set the requisite quantity of electric energy in motion. But
it is the fact that wireless messages, if regulated and controlled,
can be sent and received without interfering with other wire-
less stations with which they are not concerned. The next
step in wireless telegraphy will be to ascertain the jioint of
origin from which a wireless wave is sent. That can be done
to a limited extent now, but it will become more easily accom-
plished when the measurements of electric waves and the
measurements of the sources of energy in, and produced by,
wireless telegraphic instruments can be much more accurately
measured. Tho present stage of wireless telegraphy resembles
that of cable telegraphy before electricians like Lord Kelvin
and Mr. Latimer Clark had shown that accuracy and distance
could only be attained by instruments of measured refine-
ment, and that the first step to this daidcratum was refined
measurement.

Star Maps.

In our next issue (May) we propose to coninu'nce the
series of new star maps. These will be on the system
used in Proctor's Atlas, comprising in all twelve maps.
The stars will be in white on a dark blue ground so as
to stand out clearly, oM-r which will be printed the
names of the constellations, letters (and some names)
of stars, and R.A. and Declination.

April, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

Stellar Brightness Qcr\d
Density.

By J. E. Gore, F.R.A.S.
The absolute brightness of a star, or its so-called
" magnitude," depends on three factors — (i), its
distance from the earth ; (2), its diameter ; and (3), its
intrinsic brilliancy, or the actual luminosity of its sur-
face per unit of area. The first of these factors — the
distance from the earth — has, in a few cases, been
determined with considerable approach to accuracy,
either by micrometrical observations of comparison
stars, or from spectroscopical observations of binary
stars. The second factor — the actual diameter of the
star — is more difficult to determine, and its measure-
ment has not been satisfactorily accomplished, except
in some variables of the Algol type. An approximation
to its probable value may, however, be arrived at from
other considerations. The third factor — the luminosity
of the star's surface — may be inferred — to some extent
at least — from the character of the star's spectrum.
This luminosity of surface, or intrinsic brightness, as it
is also called, probably depends on the mass and density
of the star. Two stars may have the same mass, but
one may have a large diameter and small density, and
the other a smaller diameter and greater density. The
difference is probably a function of temperature. And
then the question arises, which of the two stars will be
apparently the brighter? We know that heat causes a
mass of gas to expand, and the greater the heat the
greater the expansion. And with a gi\en mass, the
greater the expansion the smaller the density will be.
This is evident. Hence a star with a high temperature
will have a large volume and small density. And it
seems highly probable that the higher the temperature
the greater will be the luminosity of its surface. From
this it would follow that a star with a high temperature
would have a large volume and light-giving surface,
and also a greater luminosity of surface, and both
causes would thus combine to increase its apparent
brilliancy. This would not, however, apply to the
nebulae, but only to bodies, like the stars, which have
consolidated to a certain extent.

It is now usually admitted that stars with the Orion
type of spectrum (B, Pickering), such as Bellatrix
(7 Orionis), 5, e, and f Orionis,' are — with the possible
exception of the " Wolf-Rayet," or bright line, stars —
the most luminous among the brighter stars. Next to
these come stars with the Sirian type of spectrum (A,
Pickering), followed probably in decreasing order of
surface luminosity by stars of the second (or solar)
type, and then by the third and, perhaps, the fourth
type stars. The " Algol variable " U Ophiuchi has a
spectrum of the Orion type, and some of the other
" Algols," such as Algol itself, X Tauri, and V Puppis,
show a spectrum intermediate between the B and A
type. These will be considered further on.

The probably great luminosity of stars with the
Orion type of spectrum is shown by the fact that
Sir David Gill finds that the parallax of Rigel is almost
certainly not more than the hundredth of a second of
arc, and yet it is one of the brightest stars in the
heavens; se\enth in order of brightness, according to
the Harvard photometric measures. At the vast
distance indicated by this minute parallax our sun
would be reduced to a star of about the tenth magni-
tude, and would, therefore, be invisible even with a
binocular field glass. Rigel is, therefore, about 7,800
times brighter than the sun would be if removed to the

same distance. It has a small companion of the eighth
magnitude, but as the pair have not yet been proved to
be a binary (although the companion itself, which is
double, probably is), we cannot determine its mass.
But it is evident that it must be a body of enormous
size and great luminosity of surface to shine as brightly
as it does at such a vast distance from the earth — over
300 years' journey for light. Comparing it with Sirius,
whose mass and parallax have been well determined, I
find that the mass of Rigel is probably about 20,000
times the sun's mass.

The great brilliancy of stars with the Sirian type of
spectrum is shown by Sirius itself, the distance of which
is now well determined. From its apparent brightness
and parallax I find that Sirius is about 31.6 times
brighter than the sun would be at the same distance.
From the orbit of its satellite Dr. See finds the mass of
the bright star to be 2.36 times the sun's mass, and
from this it follows that its real brightness is about 18
times greater than that of the sun in proportion to its
mass. Its spectrum shows that it is probably at a
higher temperature than our sun. Its volume is,
therefore, probably larger, and, as Dr. See says, there
" is some reason to suppose that Sirius is very much
expanded, more nearly resembling a nebula than the
sun." But here the question suggests itself. Is its
greater brilliancy due to its larger volume, and, there-
fore, smaller density, or to its greater surface
luminosity, or to both causes combined? As it is 31.6
times brighter than the sun, a diameter equal to the
square root of 31.6, or 5.62 times the sun's diameter,
would give the necessary brightness, if the surface
luminosity of Sirius and the sun were the same.
Assuming this for a moment, I find that with a dia-
meter of 5.62 times the sun's diameter — or about five
millions of miles — its volume would be 177 times the
sun's volume, and its density only o.oig (water=i).
This seems improbable, judging from the known case
of Algol, which has a much higher density than this.
We may, therefore, conclude, I think, that the great
brilliancy of Sirius is probably due to both causes com-
bined— namely, a somewhat larger volume and a
greater luminosity of surface than the sun, both
probably due to its higher temperature. If we assume
its density to be the same as that of Algol, say 0.34,
we have the diameter of Sirius about 1,860,000 miles,
and its luminosity about seven times that of the sun.

The well-known double star. Castor (a Geminorum),
has a spectrum of the same type as Sirius. The orbit
is rather uncertain, but Dr. Dobeeck has recently found
a period of 346.82 years, with a semi-axis major of
5" 756. A doubtful parallax of o'J.igS was found by
Johnson. From these data the mass of the system
would be only 0.2042 that of the sun. In 1894 the
fainter component of the pair was found by
Belopolsky to be a spectroscopic binary with a period
of about 2.98 days, and an orbital velocity of 20.7
miles a second, the companion being relatively dark.
If we assume that the components of the spectro-
scopic pair are equal in mass I find that its mass would
be o.ogii of the sun's mass. Now as the brighter
star of the visual binary is one magnitude brighter than
the companion, its mass would be — if of the same sur-
face luminosity — four times that of the other, or 0.3644.
Hence the total mass of the system would be 0.091 i-f
0.3644, or 0.4555 of the sun's mass. We may, there-
fore, conclude from the spectroscopic observations that
the mass of the system is comparatively small.
Assuming the masses found above, namely 0.091 1 and
0.3644, the areas of their surfaces would be 0.2024 and

KNOWLEDGE & SCIENTIFIC NEWS.

[April, 1905.

0.5102, or a total surface of 0.7126. Now the mass of
Sirius being 2.36, its relative surface would be— if of
the same density as Castor — 1.7726. Hence the sur-
face of Sirius would be 2.487 times that of the com-
bined surfaces of Castor's lucid components. But
Sirius is 3.16 magnitudes {i.5Si-i.5Sj brighter than
Castor. From these data I find that the parallax of
Castor would be about o'/. 136, which docs not differ
widely from the result found by Johnson. The brighter
component of this interesting pair has recently been
found at the Lick Observatory to be also a spectro-
scopic binary, but the period lias not yet been deter-
mined. The fact that bolh components are spectro-
scopic binaries makes Castor one of the most
remarkable objects in the heavens.

For * Equulei, a binary star with the very short
period of 5.7 years, Hussey finds from spectroscopic
measures a parallax of ©".O/i, and a combined mass of
1.89 times the sun's mass. He says, " The com-
ponents of the pair are slightly unequal in brightness,
and, perhaps, also in mass. One may be as massive
as the sun, but it cannot much exceed it."* The
parallax found by Hussey would, I find, reduce the
sun to a star of 5.81 magnitude, and as the photo-
metric magnitude of * Equulei is 4.61, we have the
star 1.20 magnitude, or three times brighter than the
sun. Assuming that the masses of the components are
1. 00 and 0.89 (as suggested by Hussey), I find that if
the surface luminosity of each were equal to that of
the sun, the combined light of the two components
would be 1.9247, or nearly twice the sun's light. The
star's spectrum is of the type F, probably indicating a
somewhat brighter sun than ours. The difference in
the results found above is, therefore, not inconsistent
with the parallax found by Hussey. A comparison with
Procyon is also confirmatory of Hussey's result.

Let us now consider the case of the bright star
Procyon, which has a spectrum F 5 G, or intermediate
between that or 0 Equulei and the sun. The parallax
is about o''.32s, and the mass of the system is, there-
fore, from Dr. See's orbit of the satellite, 3. 627 times
the sun's mass, that of the bright star being about
three times the mass of the sun. At the distance
indicated by the parallax the sun would, I find, be
reduced to a star of 2.51 magnitude, and as the magni-
tude of Procyon is 0.48, we have the star 2.03 magni-
tude, or 6.487 times brighter than the sun. As,
however, the mass of Procyon is three times the sun's
mass, the star should be— if of the same densitv and
surface luminosity, 2.08 times brighter than the' sun.
Hence it follows that Procyon is really ';',"' or 3.1
times brighter than our sun in proportion to its mass.
This may be due either to a larger size, and, there-
fore, less density than the sun, or to a greater
luminosity of surface per unit of area. Probably both
causes combine to produce the increased brilliancy,
and the result seems to agree well with the star's
spectrum, which probably indicates a slightly more
luminous sun than ours.

fhc binary star 70 Ophiuchi has a spectrum inter-
mediate between the .second and third types (K, Picker-
ing), probably indicating a rather fainter bodv than our
sun. An orbit computed by f)r. See, combined with a
parallax of oH.ift found by Schur, gives a combined
ma.ss of 2.94 times the sun's mass. This parallax
would reduce the sun to a star of about 4.05 magni-
tude, and as the photometric magnitude of 70
Ophiuchi is 4.07, the star is about equal to the sun in

'Aslr,:hliv:ii-,il /..,/im,i/ |i>nf. ,,.^,

brightness. But as the star's mass is 2.94 times the
sun's mass, the star should be, if exactly comparable
with the sun, about twice as bright. Hence it would
follow that the surface luminosity of the star is less
than that of the sun — about one-half, and the spectrum
indicates that this is probably the case.

Let us now consider the case of the " Algol vari-
ables." r'or .Mgol itself, \'ogel found from spectro-
scopic observations the diameter of the bright star to
be 1,074,000 miles, with a mass of 4-9ths of the sun's
mass, and for the " dark " companion a diameter of
840,600 miles and a mass of 2-9ths of the solar mass.
This result was obtained on the assumption that both
components are of equal density — about one-third that
of water. But that a dark body of such large size
should have the same density as a bright body, like
Algol itself, seems highly improbable. The density of
the planet Jupiter — which has some inherent heat of its
own — is about 1.30, and that of Saturn about 0.68.
We should, therefore, expect that a large body, like
the companion of Algol, would have a considerable
amount of inherent light, or surface luminosity. Let
us see what brightness it could have without sensibly
affecting the obser\ed light variation of .Algol. That
is, what is the maximum brightness which the com-
panion might have without producing a secondary
minimum of light when hidden behind the disc of the
bright star? Chandler finds for Algol a parallax of
o'i.o-,. The sun placed at the distance indicated by this
small parallax would be reduced to the light of a star
of 5.84 magnitude, and the photometric magnitude of
Algol being 2.31, it would be 3.53 magnitude, or nearly
26 times brighter than the sun. Let us assume that
the companion has this magnitude of 5.84 — which it
might have without the spectroscope showing it. Then
when in the course of its orbital revolution round Algol
it is hidden behind the bright star, the normal light of
.\lgol would be reduced by its 27th part. This means
that the light of Algol would be diminished by about
0.04 magnitude, or from 2.31 to 2.35, a difference
which would not be perceptible to the naked eye, and
could hardly be detected with certainty by even the
most delicate photometer. The spectrum of Algol is,
according to Pickering, B 8 .\, that of Sirius being A.
Comparing the two stars, and assuming the surface
luminosity to be the same, I find a parallax of o'.'. 1 1 for
Algol. This would reduce the sun to a star of 4.84
magnitude, and if we suppose the companion to have
this brightness, then .Mgol would be about 10 times
brighter than its companion, and when the latter is
hidden behind the brighter star, the light of Algol
would be reduced from about 2.31 to 2.41, and even
this difference could hardly be determined with cer-
tainty. It would seem probable, therefore, that the
companion of Algol has some inherent light of its own,
and is not quite a " dark body." -Assuming a parallax
'of o".o7, I find that the surface luminosity of Algol
itself would be 17 times that of the sun.

In the Algol system the components are separated
by a distance of o\er two millions of miles (between
their surfaces), but in some of the " Algol variables "
the components revolve in contact, or nearly so. .Some
have both components bright. Examples of this type
of variation are P Lyr;c, U Pegasi, V Puppis, X
Carinae, and RR Centauri. The characteristics of
the light fluctuations are, according to Dr. A. W.

• It has been recently found thai a difference in brighlncss of
two maRniludes between the components of a spectroscopic
binary is sufficient to obliterate the spectrum of tlic fainter
component.

April, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

Roberts*, as follows : (i) " continuous variation, in-
dicating that the component stars are in contact," and
(2) two maxima and two minima, showing that the
components are both bright bodies. The variation of
P Lyra; is well known. It is not usually considered
as an Algol variable, but it now seems probable that
it should be included in that class. Myers finds that
j3 Lyrie probably consists of two ellipsoidal components
revolving nearly in contact, the mass of the larger
component being 21 times the mass of the sun, and
that of the smaller g| times the sun's mass. He thinks
that the mean density of the system " is comparable
with atmospheric density " — that is, that they are " in
a nebulous condition." If this conclusion is correct
their diameters must be enormous. Taking the density
of atmospheric air as 814 times less than that of water,
I find that the larger component would have a dia-
meter of about 25 millions of miles, and the smaller
about 19 millions. The parallax of ^ Lyra? has not
been ascertained, but supposing it to be about one-
hundredth of a second, the sun would be reduced to a
star of about the loth magnitude. The maximum
brightness of the star is about 3.5 magnitude. It would,
therefore, be — with the assumed parallax — 6^ magni-
tudes, or about 400 times brighter than the sun.
From the diameters found above, the combined sur-
faces of the two components would be 1,332 times the
sun's surface. Hence their surface luminosity would
be less than one-third of that of the sun. This would
agree with Homer Lane's law, by which a gaseous
body gains in heat as it consolidates, and f* Lyra is
probably in a very early stage of stellar evolution. If
the parallax is larger than assumed above, the surface
luminosity would be still less.

Another remarkable star is the Southern Algol vari-
able, V Puppis (Lacaille 3105). Both components are
bright. The spectrum of the brighter component is,
according to Pickering, of the " Orion type," B i A,
and that of the fainter B 3 A. The period of light
variation is 1.454 day. The spectroscopic measures
show that the relative velocity is about 380 miles a
second. The combined mass of the system is, there-
fore, about 70 times the sun's mass. As the star is
variable in light, the plane of the orbit must necessarily
pass through the earth, and the accuracy of this re-
sult for the mass is, therefore, certain. This great
mass, and the star's magnitude — about 4.50, shows
that it must be at an enormous distance from the earth.
According to Dr. A. W. Roberts, the density of the
components cannot exceed 0.02 of the sun's density,
and he finds that they " revolve round one another in
actual contact." Assuming this density and a mass of
35 times the sun's mass for each component, I find that
the diameter of each would be about loi millions of
miles. Now, comparing it with Algol, of which the
diameter and mass are known, and assuming the same
surface luminosity, I find that the parallax of V Puppis
would be about o".ooi8, or a light journey of about
1,800 years. As it lies in or near the Milky Way, it
may possibly be one of the larger stars of the Galaxy.
The parallax found above would indicate that the star
is about 5,000 times brighter than our sun would be if
placed at the same distance. The star is thus a very
remarkable and interesting object. Its mass is very
large, its density is very small, and the intrinsic
luminosity of its surface is very high. Its distance
from the earth is very great. Its orbital revolution is
very rapid, and the variation of light is small and very
regular. It is, in fact, one of the most remarkable
objects in the heavens.

'Monthly Notices, R. A. S., June, 1903.

CORRESPONDENCE.

Creation of Species.

To THE Editors of " Knowledgf.."
Sirs, — Replying to Mr. Herbert Drake's letter in your March
number, the strong; hold which the "dogma of coiislancy of
species " had obtained amongst theologians of that period is
illustrated by the fact that Robert Chambers published
"Vestiges of the Natural History of Creaton" anonymously,
in order to avoid involving the firm with which he was con-
nected in theological controversy, and the storm which followed
Chas. Darwin's "Origin of Species" shows that this precaution
was justified.

From the active part taken by Bishop Wilberforce and other
prominent Churchmen of the time in this controversy, it would
appear that the objections taken to the dogma can scarcely be
dismissed as "popular prejudice or superstition," as sug-
gested by Mr. Drake. There can be no doubt that the strong
belief in this dogma held by the majority of the members of the
churches, whether popular prejudice or not, delayed the advent
of the theory of evolution.

One grave objection taken to the theory of evolution was
that it did not accord with the literal reading of the first
chapter of Genesis. This was also an important objection
raised in the heated discussion which followed the pubUcation
of " Essays and Reviews," in which discussion many of our
Bishops took a leading part.

J. C. Shenstone.

" Common " ats a. Scientific Ternn.

The word "Common "is a useful one for ordinary use, but
as a scientific term it has many disadvantages. Not the least
of these is its ambiguity. We may say " the common snipe,"
or " the snipe is common there," or " the snipe is common to
several countries," and use the word thus in three different
ways, and not be sure that we shall be perfectly understood in
any of them. I had always myself understood the expression
"the common snipe " to mean the snipe that is ordinarily
meant by the word snipe without qualification. But Mr. F. G.
Aflalo {" Knowledge " vol. 2, p. 52) takes it to meau the
" prevalent " species of that bird.

With regard to the Latin equivalents, coininunisin either of
these senses simply is not Latin. It can only, in that language,
mean common to two or more places. While vulgaris means
" ordinary," " as used by uneducated people."

In this latter sense, which is I think the one in the minds of
most people, one could well speak of " The Common Dodo,"
so as to distinguish the Didus Incptus of Mauritius from the
less well-known Didine birds of Rodriguez and Reunion. Vet
Mr. Aflalo would deny its appropriateness to any species
which is growing extinct.

Another objection to vulgaris is that it connotes the idea
of popular error ; it would be more appropriately used to
stigmatise an incorrect title, than as a scientific distinction.

To introduce the term " common sense " in this connection
seems like making " confusion worse confounded." We are
given three derivations of the expression. First, a man's five
senses were supposed to be the five avenues of one common
organ, hence styled " the Common Sense." Next, there is the
meaning of " the ordinary judgment of mankind." And then
there is the philosophical definition, which makes it equivalent
to the first principles of belief which ordinary men accept.
None of these have anything to do with the Latin communis
sensus, or the feeling common to all men as to what is right
and proper. In actual use these various ideas are so
confused that one can rarely meet two people to whom the
word conveys the same meaning. I remember a scientist
telling me that his common sense told him that miracles do not
happen. I pointed out to him that whether that were an
argument for or against miracles depended on the meaning
attributed to " common sense." Once I heard, shortly after
one another, two preachers, one of whom denounced, and the
other pleaded for, the use of common sense in religion. They
both meant the same thing, but used the term in contrary
meanings ! We need to be well on our guard against such a
doubtful expression.

Verwood, Wimborne, March 13. Herbert Drake.

KNOWLEDGE cS: SCIENTIFIC; NEWS.

[Apkii,, 1905.

A White Raccoon Dog.

A New Species.

By Emile GbARiNi.
This strange specimen of dog was obtained by Captain
Golding in Nagasaki, Japan, of a native dealer in live
animals, who was unable to give its history, and could
only state that it came from the northern portion of
Japan. It bore a slight resemblance to an immature
Arctic fox, but it was at once apparent that the creature
was not a fox, and during the 15 months it has lived in
the Zoological Park, of .\ew York, it has not under-

weak. Although the claws are long, they are slender,
remarkably straight, and have little strength, either for
offence or defence. The ears are short, and in shape
most nearly resemble those of the .'\rctic fox. As a
whole, this animal is not physically robust, nor is it
vicious in temper. Its teeth are small and weak, and
it is poorly equipped for self-preservation. It requires
a home that is not overrun by bears, wolves, foxes, &c.,
and very probably it inhabits moist lowlands rather
than dry and rugged mountains. The feet are very
thinly haired as if this creature had been specially fitted
for life in swamps and tundras, where frequent wading
in water is necessary.

On the neck, body, tail, and thighs the pelage is
dense and fine, and consists of two coats. On the

\\ hiLc ka^L.,.jii IJu;:

gone any noteworthy change in pelage, nor has it
perceptibly increased in size. It therefore seems con-
clusive that the creature is adult, and that its colours
are constant throughout the year. An examination of
its external characters revealed an unmistakable re-
semblance to the raccoon dog of Japan and China, but
it is not an albino individual of this well-known species.
There appears to be no escape from the conclusion that
this specimen represents a species hitherto unknown.

In general form this animal resembles a sharp-nosed
raccoon. Its weight is 7^ pounds, its length of head
and body 21 inches, the height at shoulders being 10.29
inches. The tail is 6.29 inches to end of vertebra;, and
8 inches to end of hair. The back is highly arched, its
head is carried rather low, and its tail has a very
raccoon-like droop. The feet are small and delicately
formed, and the front feet in particular are short and

upper surface the inner coat is very fine and woolly,
and about one inch long. The outer coat is two inches
long, straight, and of coarser texture, as is usual in a
rain-coat. The hair on the tail is abundant, but ends
abruptly at the tip, like a tail artificially shortened.
The pelage on the lower half of each leg is exceedingly
scanty. On the abdomen the pelage is about one-half
the length of that on the upper surface, and consists
chiefly of the fine woolly under-fur. Excepting upon
the feet and lower half of the legs, the pelage is like
that of a small .Arctic fox. The entire neck, body,
legs, feet, and tail are pure white. On each side of
the head is a large and conspicuous triangular patch of
blackish-brown hair, the top of the muzzle is white, and
the upper lip shows a light-coloured blending of brown
and white. The forehearl is white; the ear is conspicu-
ously dark, the edge being quite black.

April, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

8=5

ASTRONOMICAL.

Secular aind Seasonal Changes orv the
Moorv's Surface.

For some years past Professor \V. H. Pickering has been
engaged in a series of special studies of the lunar surface.
The work has been undertaken in connection with the Astro-
nomical Observatory of Harvard College, and a full account
of the results obtained will be found in volume 53 of the
"Annals" of that institution. .A short ycsuntc has recently
been presented in Xatiire over the signature of Professor
Pickering.

Briefly summarised, it may be stated that the evidence of
structural change on the visible hemisphere of our satellite has
been suspected from time to time by various eminent selenogra-
phers, notably by Madler, Schmidt, Webb, Elger, and Niesen.
In more recent ye.ars the work of Professor Pickering during a
long series of special observations in Peru, Jamaica, and
California, has led him to the conclusion that physical
changes do occur upon the moon, and that they may be
classified under three heads, due respectively to (i) volcanic
action, (2) formation and melting of hoar-frost, (3) growth and
decay of vegetation.

The first class of phenomena has its most forcible example
in the crater Linne, which, according to Lohrmann, Madler,
and Schmidt, prior to 1S43, had a diameter of between four
and seven miles, whereas its present diameter is three-quarters
of a mile. A new crater has also been announced in the
vicinity of the well known formation Hyginus. Again, the
floor of the crater Plato has repeatedly furnished new forma-
tions under telescopic examination at various times. Picker-
ing's latest observations show the existence of a crescent-
shaped bank, about six miles long by one or two miles broad.
Reference to the maps made by A. S. Williams during the
period 1879-90, indicates that no object similar to that now
existing was to be seen at that time ; but the maps themselves
show that slight variations were apparent at different epochs
of observation.

Considering now the second variety of changes, there are
numerous tracts on the moon's surface which exhibit varia-
tions in light and shade, which from their character lead to
the assumption that they are due to the alternate condensa-
tion and volatilization of hoar frost. Professor Pickering
especially draws attention to the evidences of aqueous erosion
on the central peaks of Theophilus and Eratosthenes, and
further considers that the strongest evidence for the former
presence of water lies in the dried-up river-beds, of which the
best example is to be seen on the eastern slopes of Mount
Hadley, at the base of the Appenines. Another, discovered
only in the summer of 1904, lies about 60 miles due south of
Conon. Still more positive, however, is the evidence the
author gives of personal observations of the periodical changes
in the craters Messier and Messier A, according to the pro-
gress of the lunar day — changes which he asserts inay be
followed with a telescope, of 4 inches aperture under good
atmospheric conditions.

The third class of phenomena, possibly due to the growth
and decay of vegetation, are stated to be more conspicuous
than the effects produced by the two former causes. Repro-
ductions are given of photographs obtained by Professor
Pickering in the island of Jamaica in 1901, showing undoubted
evidence of changes in the crater Eratosthenes, progressing
very regularly with the age of the moon. Every precaution
has been taken to exclude effects due to varying angles of
lighting, and it remains quite certain that growths of dusky
matter have taken place. As we have no knowledge of any
mineral matter which could produce this appearance, it seems
proper to ascribe it to vegetable growth.

Law of the Sun's Rota^tion.

Professor N. C. Duner, of Upsala, has within the last
few years been engaged in a series of observations for the
determination of the Sun's rotational velocity at different
heliographic latitudes. The observations were made by deter-
mining the linear velocity at various points on the Smi'slimb,
by measures of the displacement of spectrum lines in the line
of sight. In the latest list given he brings together results
obtained from various determinations during the period 1887-
igoi. The following is a summary of the values found, taking
zones of latitude of 15°.

Heliocentric
latitude.

Rotation

Velocity at

Limb.

No. of
Observation

^ cos p

Angle of

Daily
Rotation.

K.M.

Degrees.

0-4

+ 2-o8

183

14 770

14-77

150

+ i'97

180

13989

14-48

30-1

+ I 70

1 84

12 072

13-95

450

+ I 27

181

901S

12-75

600

+ o-8i

183

5-752

11-50

750

+ 039

1S4

2-769

10 70

Ne>v Determination of Solar Constant.

Monsieur A. Hansky has recently published an interesting
account of a series of determinations of the solar constant by
actinometric observations on the summit of Mont Blanc,
.^s given by various observers, this important quantity has
been assigned many values, of which the following are the
more important : —

Pouillet .. .. .. .. .. .. 1-763

VioUe (Mt. Blanc) 2-54

Crova (Mt. Ventoux) 2-83

Langley (Mt. Whitney) 3068

Savelieff .. .. .. .. .. .. 347

Angstrom (Peak of Teneriffe). . .. .. 400

The two latter values are obviously too high in view of the
more recent refined determinations. Later determinations
with the bolometer by Langley gave the revised value of 2-54
as the more probable value.

M. Hansky's observations were made on the Mont Blanc
station during the years 1897,1898, and 1900, giving the mean
value of 3-29 as his final result. The series of igoo were made
under specially favourable conditions, and full details are
given of that section. During twelve days' sojourn there he
secured five actinometric curves, and numerous direct deter-
minations of the solar thermal radiation, all of the observations
being obtained with Crova's actinometer. From July 23 to 28
the weather was extremely fine, but the temperature high.
The air was almost quite calm, but the aerial currents from
the valley were evidently strong, as indicated by the formation
of cumuli above the summit of the mountain. The hygro-
metric state at the summit was 70 per cent., indicating a
vapour tension of about 1-2 mm.

The polarisation of the sky was about 0-50, and never ex-
ceeded 0-67 ; the colour of the sky was normal blue ; baro-
metric pressure varied from 426 to 430 mm.

The actinometric curves were very regular during the morn-
ing and evening hours, but showed strong depressions a little
before and a little after midday (from 9 h. — 1 h.), exactly as
Crova had already found at Montpellier and Mont Ventoux.
This depression may in part be attributed to the ascend-
ing air currents from the valley carrying with them large
quantities of aqueous vapour, thus exerting considerable ab-
sorption of the calorific rays.

* * *

Seventh Satellite of Jupiter.

A telegram received from the Kiel Centralstelleon February
28, too late for inclusion in our last issue, announced the dis-
covery of yet another satellite of the planet Jupiter, presum-
ably by Professor Perrine, although the authorship was not
mentioned.

The new satellite was stated to be of the i6th stellar mag-
nitude, and its position when measured was

Position angle from Jupiter = 62° )_ d.

Distance = 21' ' 1905, February, 25-6

KNOWLEDGE c\: SCIENTIFIC NEWS.

[April, 1905.

The daily motion was determined to be 6c- of arc in a south-
easterly direction.

Professor Campbell, in a later ccnErmalion of the above,
informs us that the discovery was made by Professor Perrine
with the Crossley reflector of 36 inches aperture, and that the
object had been under observation since January 2. The
apparent motion of the satellite is direct, and the provisional
elements indicate an orbit considerably inclined to the
ecliptic.

CHEMICAL.

By C. .A. MiTCHi I.I.. H.A. lOxon.i. K.I.C.

The Electric Bleaching of Flour.

A NEW electric process of producing an extremely white flour
has recently been adopted in Paris. Specimens of the flour
before and after the treaiment have been examined by
M. Balland, who finds that although the whiteness is
undoubtedlj- increased, yet the flavour and odour are not so
good as before. This is shown by the analyses to be due to a
partial decomposition of the wheat oil, to which flour owes its
aroma, and the flour increases greatly in acidity throuj^h this
decomposition. In fact the process is essentially an artificial
ageing accompanied by the usual whitening that occurs in old
flour.

♦ » »

Ra.dio-Active Substa.nces in Natural
Watters.

The water and the gases of the hot springs in Wiesbaden
have been shown by Dr. Henrich to be strongly radio-active,
whilst the stalactites also exhibited the same phenomenon.
The water could be rendered nearly inactive by boiling it so
as to expel the dissolved gases, but the stalactites retained
their radio-activity on keeping. The element helium, which is
known to be formed from radio-active substances, has been
identified by M. C. Mouren in the gases from 12 French
mineral springs, some of which contained 50 times as much as
the others. Helium has also been detected by Sir James
I^cwar in the gases from a mineral spring in Bath.

* » ♦

The Gum Disease of the Sugar Ca-ne.

The Australian sugar cane suffers from a disease which is
characterised by the formation of a yellow gum within the
vascular fibres of the plant. It was first described in 1S93 by
Mr. Cobb, who attributed it to a species of bactcriimi which he
isolated from the gum, but his attempts to inoculate healthy
plants with the disease were inconclusive. Professor E. Smith,
however, has recently prepared pure cultivations of the micro-
organism which he terms pseinldmnniis vmcularum (Cobb), and
has successfully inoculated common green sugar canes with
them so as to produce all the symptoms of the Australian gum
disea.se. The acidity of the juice appears to have considerable
influence upon the susceptibility of the plant to infection, for
two other varieties of sugar cane, Louisiana .No. 74 and the
common purple cane, with a much more acid juice, offered
great resistance to the attack of the psciidnmoiias. The prac-
tical remedy of planting varieties of cane that are not readily
affected has already given good results in the sugar plantations.

• ♦ »

The Use of Specific Sera in Chemical
Analysis-
One of the most difficult problems in analytical chemistry is
to distinguish between the flesh or blood of different animals,
and until recently the tests employed left much to be desired.
In I NfjS, however, it was discovered by M. Borget that when
a rabbit was inoculated with the s<;nmi of cow's milk its own
blood serum became so modified as subsequently to give a
precipitate when added to the serum (whey) of any cow's
milk. This discovery was shown by Dr. von Kigler (1902) to
be capable of extension, and that when rabbits were inocu-
lated with extract or broth of a given animal the serum from
their blood would then give a precipitate with extracts of the
flesh of that particular animal, but not with those of any other
animal. Thus sera rendered specific to horseflesh would not

react with extracts of beef venison, pork. Sec. A still more
important development of this idea seems likely to effect a com-
plete revolution in the methods of examination in criminal cases.
For when human serum is injected into a rabbit or guinea-pig
their sera become specific for human blood serum, and the test
can be applied even in the case of a blood stain several months
old. In a recent criminal trial in France the prisoner asserted
that certain stains were caused by rabbit's blood. Sera
specific for rabbit's and human blood were therefore prepared,
and when it was found that a saline extract of the stain gave
no pronounced reaction with the former, while it did so with
the latter, the chemical experts considered that they were
justified in reporting that the stain was certainly not rabbit's
blood, but in all probability consisted of human blood. The
nature of the specific substances in the sera is not known, but
they are probably albuminous derivatives formed by certain
constituents in the rabbit's cells in their attempt to expel the
intruding substance. They can be precipitated and dried
at a low temperature in a vacuum, and the pracipitiiics thus
obtained only require the addition of water to produce a solu-
tion acting almost as readily as the fresh specific serum, and
have also the great advantage that they can be kept in the
dark for months without undergoing any change.

GEOLOGY.

Conducted bv 1".ia\.\ki) A. Mai;tin. F.G.S.

A Well -Boring att Holborn.

\\'ater to the extent of 3000 gallons per hour is being
obtained from a new well at the Birkbick Bank, Holborn,
F.C. The strata passed through in the boring is as follows,
kindly supplied b\' Mr. Heywood, of the firm of Messrs.-
Robert Warner and Co. : —

Alluvial

12 Basement.
15 Ballast.

London ( 85 London clay.

Clay 15 Coloured clay.

Oldhaven 7 Sand and water.

Woolwich I 15 Coloured sandy clay and pebbles.

and Reading - 2i Sand pebbles and oyster shells.

Beds ( 4 Sand and small pebbles.

Thanet sand 22^ Thanet sand and water.

Chalk 284" Chalk.

The well is sunk 5 feet into the chalk (5 feet diameter),
lined with brickwork and iron cylinders; then an open sinking
in the chalk for about 30 fcst, and a boring in the bottom of
the well to 462 feet. It will be seen that there is a total thick-
ness of 178 feet above the chalk.

» # *

A New British Tortoise.

An interesting find is recorded from the lower Headon
Beds of Hordwell, Hants, in the shape of bones of the
carapace and plastron of a new species of tortoise. If has
been given the name of Xicoria Hcadoiicnsis by Mr. R. W.
Hooley, F.G.S. The bones were scattered over a space of
about four s(|uare feet, the broken edges of the entoplastral
and right hyoplastral being found sticking out of the face of
cliff. The specimen has been referred to the Tcstndiuidir,
genus Xicoria, this being the first record of the genus from
Kngland. To-day it is found in the East Indies and in South
America.

MaLryla-nd Miocene Forma.tion.

The two new volMints of the Maryland Geological Survey,
dealing with the Miocene deposits of that State, are models of
what Government publications should be. Comparisons of
these voluuies with those isNued \>y our own Survey are forced
upon our notice, and we can only hope that in the course of
time our own Government may be induced to make larger
grants towards our half-starved Geological Survey. Of the
two volumes now to band, one contains over 500 excellently-
printed pages of text, whilst the second volume contains 125
full-page engravings of fossils. The Miocene deposits of Mary-
and have long been known to geologists for the rich faunas

April, 1905.'

KNOWLEDGE & SCIENTIFIC NEWS.

which they contain, and collections brought therefrom hav
for many years enriched museums all over the world; Con-
sidering the barrenness of our own country as regards this
formation, it is interesting to note that the Maryland Miocene
shows a greater diversity of species than does the Eocene. The
former are known as the Chesapeake group, from the superb
sections seen on the shores of Chesapeake Bay. The group
is divided into three well-defined formations, called Calvert,
Choptank, and St. Mary's. They lie uncomfortably upon the
Eocene, overlapping them along their western border. Beds
of nearly pure diatomaceous earth, of between 30 and 40 feet
thick, are met with in the lower portions of the Calvert forma-
tion ; whilst the Chesapeake group, as a whole, is characterised
by the great masses of molluscan shells which it contains, these
forming sometimes so large a proportion as to produce nearly
pure calcareous strata. The State Geologist (Mr. William
Bullock Clark) and his assistants are to be congratulated upon
the thoroughness and excellence of their work.

ORNITHOLOGICAL.

By W. P. PvcRAi-T, A.L.S., F.Z.S., M.B.O.U., &c.
Ivory Gull in Fife.

An Ivory Gull {Pdi;opliila ebnrnca) is reported, by the
" Annals of Scottish Natural History," to have been seen in
Largo Bay on Sept. 15. It Hew past the observers so closely
that '-an excellent view of the pure white plumage, black eye,
and yellow bill " was obtained.

* * *

Pied Flycatcher in Fife.

Two examples of this rare visitor to Scotland are reported in
the "Annals of Scottish Natural History," as having been
seen in Fife during May, 1904 — one at Gilston on the Sth
and one at Largo on the 12th. Both left on the 14th of this
month.

* ■» *

Nutcracker in Kent.

At the meeting of the British Ornithologists' Ckib held on
January 18, Dr. N. F.Ticehurst exhibited a nutcracker (Niicifraga
caryocatactcs), which had been killed on the 14th of that
month by a gamekeeper at Benenden, in Kent. It proved,
on dissection to be a male. This makes the fourth occur-
rence of this bird in Kent.

* * »

Sa-bine's Snipe in Anglesey.

A melanistic variety of the common snipe, known generally
as " Sabine's snipe," was killed in a turnip-field in Anglesey
on January 21.

* * *

A White Water Rail.

Mr. R. Patterson, in the Irish yattintlist for February,
records the fact that a pure white water rail has just been shot
at Seaforde, Co. Down. While the beak retained its normal
colour, the legs and feet were of a pale pink orange. The bird
was in splendid condition, and weighed 55 02s.

* * ♦

Little Auk at PortmoLrnock.

Mr. J. Turubull, in the Irisli A'(7<»r((/;i/ for February, reports
the fact that a little auk (Mcrgiilus allc) was picked up in an
exhausted condition in a lield at Portmarnock on November 27.
This makes the sixth occurrence of this bird in Co. Dublin.

Th3 Pacific Eider.

In our notice in February of the occurrence of the Pacific
Eider (Somatcria V-nigra), we inadvertently described it as
having been shot at Scarborough. We learned, too late, that as
a matter of fact it was killed at Graemsay, Orkney, in the
early morning of December 14, by a wildfowler named George
Sutherland, and was sent, with some common eiders, to a
dealer at Scarborough.

The Migration of Birds.

We are glad to say that the British Ornithologists' Club has
just appointed a Committee to inquire into the " migration of
birds within these islands." The need for such an in(iuiry is
now most necessary since this work has been relinquished by
the British Association.

For the present observations are to be confined to the
" arrival in England and dispersal through England and Wales
of the thirty or so strictly migratory species which winter
abroad and nest fairly commonly in England and Wales."
Later, it is proposed to considerably extend the range of these
observations.

Thus it is suggested that the services of lighthouse keepers
should be enlisted, subject to the permission of the Master and
Elder Brethren of the Trinity House. The keepers in ques-
tion are to be asked to fill up schedules containing informa-
tion as to the birds observed or captured at the lighthouses,
and to forward the wings and feet of birds killed at the lamps.
In short, they are to continue the work which has been so
successfully carried on during the last few years by the Com-
mittee of the British Association.

Besides these helpers, other observers from a large
number of centres in England and Wales are to be asked to
co-operate, and to fill up similar schedules.

The fact that Mr. Eagle Clarke has promised to give his
advice and help should go far to ensure success for this most
valuable work.

* * *

The Study of Hybrids.

Hitherto the value of hybrid birds, from a scientific point of
view, has been open to question, inasmuch as the parentage
of the particular hybrids can never be positively demonstrated.
Even when this parentage is known no great value can be
attached to the fact. This is by no means the case, however,
with the experiments now being carried out by Mr. J. L. Bon-
hote in his aviaries at Ditton Hall, Cambridge.

As a basis of operations he selected the Mallard, Pintail.
Spotted-bill (anas pa-cilorliyiicha) and New Zealand Duck (anas
suiurciliosus). The most interesting of the results so far
obtained are those of the hybrids Mallard x Spotbill x
Pintail. The offspring of this complex mixture of blood were
divisible into two races — a light and a dark race. Of these
the drakes in full plumage favoured the Mallard and Pintail
about equally, whereas in eclipse plumage they resembled the
Spotbill. The dark females have so far proved infertile, but
this is not the case with the dark drakes when mated with
pure bred birds of either species.

Though neither the Spotbill nor New Zealand Ducks have
an eclipse plumage, when crossed with other species this
peculiar phase is always assumed. Another interesting point
which Mr. Bonhote's experiments have brought out is the fact
that while some of these hybrids resemble the parent forms,
others assume characters belonging to species which have
had no part in their ancestry ; or they develop features
entirely new, that is to say, which can be referred to no
known wild species.

The ofl'spring of the light forms prove either as hght as, or
lighter than, their parents. As these experiments are still in
progress it is probable that very substantial additions to our
knowledge of hybridization will result.
» * *

A Neu' British Bird.

At the meeting of the British Ornithologists' Club held on
March 15 an adult male of the Snowfinch (Moittifringilla
nivalis) was exhibited by Mr. M. Nicholl. This bird was shot
at Kye Harbour, Sussex, on February 22, and is the first
recorded occurrence of this species in these islands. The
Snowfinch bears a very striking resemblance to the Snow-
bunting, and is a native of the mountains of Southern Europe
extending eastwards to Palestine.

* * #

An Albino Shag in Orkney.

The Fiehl, March 4, contains an account of a true albino of
the Shag (Phalacrocoi-a.x gmcutus), which was obtained towards
the end of December last near Stromness, Orkney. A similar
example, according to the same authority, was obtained at
Mid Yell, Shetland, on February 27, 1884.

KNOWLEDGE & SCIENTIFIC NEWS.

[April, 1905.

ZOOLOGICAL,

By K. LvttKKER.

An Asiatic Ocelot.

The stTiall marbled cats known as ocelots {Felis pardalis)
have hitherto been regarded as an exclusively New World
type, where they are most abundant in Central and South
America. Re-examination of the Central Asiatic species
known as Felis tristis has. however, led the present writer to
believe that it is an Old World representative of the ocelots.
If this view be correct, it will serve to show that the ocelots
(as has always been supposed to be the case) oriRinally entered
America by way of Bering Strait. It is also urged that the
clouded leopard IK lubulosa) and the marbled cat (F. mar-
moruta) of the Indo-Malay countries are also members of the
ocelot group, but of a more aberrant type.
• * «

Arboreal Ancestral Mammals.

The majority of modern marsupials, it has been stated,
exhibit in the structure of their feet traces of the former
opposability of the thumb and great toe to the other digits ;
and it has accordingly been urged that all marsupials are
descended from arboreal ancestors. This doctrine is now re-
ceiving wide spread acceptation among anatomical naturalists,
and in a recent issue of the American Satiiralist (November
and December, 1904. p. 811) Dr. W. D. Matthew, a well-known
trans-Atlantic pala;ontologist, considers himself provisionally
justified in so extending it as to include all mammals. That
is to say. he believes that, with the exception of the duckbill
and the echidna, the mammalian class as a whole can lay
claim to descent from small arboreal forms. This conclusion
is, of course, almost entirely based upon palsontological con-
siderations ; and these, in the author's opinion, admit of our
coming to the conclusion that all modern placental and mar-
supial mammals are descended from a common ancestral
stock, of which the members were small in bodily si^e.
To follow Dr. .Matthew in his hypothetical reconstruction of
these ancestral mammals would obviously be out of place on
the present occasion ; and it must suffice to say that, in addi-
tion to their small size, they were characterised by the presence
of five toes to each foot, of which the first was more or less
completely opposable to the other four. The evidence in
fax-our of this primitive opposability is considerable. In all
the groups which are at present arboreal, the palsontological
evidence goes to show that their ancestors were likewise so ;
while, in the case of modern terrestrial forms, the structure
of the wrist and ankle joints tends to approximate to the
arboreal type as we recede in time. The available evidence, so
far as it goes, is therefore decidedly in favour of Dr. Matthew's
contention.

The author next discusses the proposition from another
standpoint — namely, the condition of the earth's surface in
Cretaceous times. His theory is that in the early Cretaceous
epoch the animals of the world were mostly aerial, amphibious,
aquatic, or arboreal, the flora of the land being undeveloped
as compared with its present state. On the other hand,
towards the close of the Cretaceous epoch (when the chalk
was in course of deposition), the spread of a great upland
flora vastly extended the territory available for mammalian
life. Accordingly, it was at this epoch that the small ancestral
insectivorous mammals first forsook their arboreal habitat to
try a life on the open plains, where their descendants develo-
ped on the one hand into the carnivorous and other groups in
which the toes are armed with nails or claws, and on the
other into the hoofed group, inclusive of such monsters as the
elephant and the giraffe.

• » »

A Fossil Loris.

The lorises or slow-lemurs, frequently miscalled sloth.s, are
peculiar to the Indian and Malay countries, where they are
represented by the slow-lorises (Xyclicehtis) and the much
smaller slender lorises ([.oris) ; the latter being restricted to
Southern India and Ceylon. Their nearest living allies are
the pottos iPcrodiclitus), of West Africa. Recently the well-
known French naturalist. Mr. G. Grandidicr, has described
an extinct lemur from the Tertiary of France, which he believes

to be nearly related to the slow-lorises, and has accordingly
named Pronycticebus gaudryi. If the determination be correct
(and the figures illustrating the memoir seem to indicate that
it is), the discovery is of considerable interest, as tending to
Imk up the modern faunas of Southern India and West
.Africa (which possess many features in common) with the
Tertiary fauni of Europe.

* * *

The Lion in Greece.

Some time ago Professor A. B. Meyer, the Director of the
Zoological Museum at Dresden, published an article on the
alleged existence of the lion in historical times in Gr?ece. A
translation of this article appears in the recently issued
.Annual Report of the Smithsonian Institution. As regards
the mention of that animal in Homer, the author is of opinion
that the writer of the Iliad was probably acquainted with the
lion, but this does not prove its former existence in Greece.
The accounts given by Herodotus and Aristotle merely go to
show that about 500 B.C. lions existed in some part of Eastern
Europe. The Greek name for the lion is very ancient, and
this suggests, although by no means demonstrates, that it
refers to an animal indigenous to the country. Although fossil
bones of the lion have been recorded, no recent remainsof that
animal are known from Greece ; but this cannot be regarded
as a matter of any importance in connection with the question.
On the wliole. although the evidence is not decisive, it seems
probable that lions did exist in Greece at the time of Herodotus;
and it is quite possible that tlie representation of a lion-chase
incised on a Mycenean dagger may have been taken from
life. In prehistoric times the lion was spread over the greater
part of Europe ; and if, as is very probable, the so called
Fi7(5 titrox be inseparable, its range also included the greater
part of North America.

It may be mentioned that the journal above-mentioned also
contains a translation of an article giving an account of the
discovery of the mammoth carcase recentl)- set up in tlie St.
Petersburg Museum. In publisliing translations of articles
of such general interest as the abovc,the Smithsonian Institu-
tion is doing good service to science, for although many of
us have a more or less intimate acquaintance with German, it
is but few who can read Russian or Norwegian.
» * »

Fish-Lizards.

Many years ago the present writer contributed to
" Knowledge " a popular account of the extinct marine
reptiles known as ichthyosaurs, or fish-lizards. The saincgroup
has afforded to Professor H. 1". Osborn the subject for an
exquisitely illustrated article in the January number of the
Century Mcif^azinc. These creatures, as anyone may satisfy
himself by a visit to the Natural History Museum, had
paddle-like limbs of a most peculiar type ; but Profes;;or
Oiborn is of opinion that these may be derived from a limb of
the type of that of the living New Zealand tuatera, a primitive
terrestrial lizard. Owing to the remarkable state of preserva-
tion of some of their fossil remains, we know not only tliat fish-
lizards had a fin on the back, and another at the end of the
tail, but likewise I hat they possessed a smooth skin and pro-
duced living yoimg; the latter feature being an adaptation to
their purelv aquatic mode of life.

* * *

Nfcw Species of Wapiti.

In the Procadini^s of the Hiolngical Society of Washington
of F'ebruary 2 Dr. C. H. Merriaiu describes the wapiti deer,
or elk (as it is miscalled in .America), of California as a new
species, under the n.iine of Ccrvu^ nannoihs. It differs from
the typical wapiti of the Rocky Mountains by its inferior
size, relatively shorter legs, and paler colour, the front of the
limbs beint' golden tawny in place of black. Of course this
animal is not a species in the sense in which that term is
employed by many naturalists, but merely a local race.
« » »

The Paddles of the Fish -Lizards.

Mr. J. C. Merriam, in the Amcriciiii Journal of Seiencc for
January, shows that so early as the period of the Trias, or New
Red S.andston(-,the fish-lizards, or ichthyosaurs, displayed two
distinct types of paddles ; the one broad and the other narrow.
The broad-paddled type (hiixosaurus) is considered to be the

April, 1905.]

KNOWLEDGE c\: SCIENTIFIC NEWS.

one from which both the broad-paddled and narrow-paddled
forms of the Lias have originated, thus upsetting the older view-
as to the narrow-paddled group being the primitive type.
* * *

Cobra Poison.

An important communication on the action on the human
system of the poison of the Indian cobra is published in a
recent issue of the Philosophical Transrictions of the Royal
Society, based on investigations undertaken at the instance of
the Secretary of State for India by Surgeon-Captain Elliot.
While earlier investigators ascribed death from cobra-venom
in most cases to paralysis of the respiratory centres, the
author concludes that the main cause is a rise of blood-pres-
sure caused by the contraction of the mieute arteries, which
thus afford a barrier to the circulation.

Papers FLead.

At the meeting of the Zoological Society on February 21,
Mr. Lydekker contributed one paper on the giraffes of Nigeria
and the Kilimanjaro district, and a second on dolphins from
India. Messrs. Thomas and Schwann gave an account of a
collection of South African mammals, describing a new species
of shrew; and Mr. Pocock pointed out that the Somali kudu
was subspecifically distinct from the typical southern form of
that animal. On March 7, at the meeting of the same Society,
notes were contributed on the marine fauna of the Cape Verde
Islands, Mr. Regan reviewing the species of certain South
American genera of fishes ; and Captain Meinertzhagen
described a new kind of oribi antelope from British East
Africa. At the meeting of the Linnean Society on March 2,
the subject of zoological nomenclature was discussed, and
the hope expressed that tautonomies, such as viilpcs vulpcs and
other comical arrangements, would be discarded.
-» « •

It is generally understood that insects, like other " cold-
blooded " creatures, have no temperature of their own, but
put themselves in equilibrium with that of the surrounding
medium, air or water. M. Acloque summarising in Cosmos
recent investigations on this subject, suggests, however,
that there are several experiments to show that the
generalisation is not true in all cases, and that there are
reasons for supposing that insects produce heat. A
Fahrenheit thermometer was found by Inch to rise seven
degrees in an ant-hill, and Swammerdam and Reaumur
observed that the temperature of beehives keeps above that of
the external air in winter. According to Huber, who repeated
these observations, this temperature is nearly constant at
88° Fahrenheit. Reaumur added that when the bees were
agitated they caused their wings to vibrate with great rapidity,
and the interior heat then increased to such a point that the
walls became warm, and sometimes even the wax melted.
However this may be, we may say that the heat given off
individually by insects is always very slight. By way of com-
pensation, they confirm the general law according to which
living creatures resist cold better as their ability to give
off heat is slighter. Caterpillars do not necessarily die when
turned into bits of ice; and this resistance to cold explains
why we can find insects in regions very near the Pole, and
why the rigours of our own winters do them so little injury.
Certain species, and in particular some lepidoptera, hatch out
only in winter, which explains again, perhaps, how it is that
some flowers like the yellow Cape jessamine, now blooming in
Surrey, can become fertilis'^d in winter. Insects bear heat as
well as cold, and Kirby and Spence have affirmed that some
can survive immersion in boiling water.

SCIENCE YEAR BOOK.

Attention may be called to the announcement that appears in
our advertisement pages of the Reduction in price of the Science
Year Book for 1905. This should be an opportunity for all
persons interested in Science to acquire, at a very small cost,
this book which Nature says " should be foitnd on the writing
table of every astronomer and meteorologist," and "all who are
interested in natural phenomena or concerned with scientific
progress."

REVIEWS OF BOOKS.

Terrestrial Magnetism and Us Causes, by F. A. Black.

(Published by Gall & Inglis ; price, 6s. net). The complex
question of the magnetism of the earth and its consequent
intfuence on the compass needle has been treated from
an entirely new basis of hypothetical speculation by Mr.
F. A. Black, in this recent work. The elucidation of the
natural laws which cause the magnetic needle to point approx-
imately North and South ; the daily, seasonal, and secular
variation in its direction, and in its inclination or dip ; the
causes of magnetic storms and their connection with sun-spots
and aurorse ; in short, every subject connected with the earth's
magnetisation and its inlfuence on the magnetic needle is
dealt with by the author in the theory promulgated by him.
He adopts the assumption, based on scientific opinion, that a
tenuous medium of an electrical nature permeates the space
through which the earth moves in its orbit; that the sun's
activity causes displacements or currents of this medium
which are impelled with great velocity towards and upon the
earth, thus causing the earth in its diurnal rotation to be enve-
loped from apex to apex by a sheet of electricity with an
apparent contrary motion, so that it is magnetised by induc-
tion, and is consequently an electro-magnet. The various
puzzling phenomena connected with the magnetic needle in
relation to the earth's magnetism are treated in an exhaustive
manner, and the deductive reasoning proved by means of
diagrams. The book is unmistakably the result of deep study
and research on the part of the author, and the able arguments
set forth in support of his theory are undoubtedly well worthy
the consideration of magnetists, physicists, and others inte-
rested in this department of science.

Astronomy for Amateurs, by Camille Flammarion, translated
by Francis A. Welby (Fisher Unwin). Price 6s. 340 pp. This is
one of those fascinating little books that do so much to spread
scientific interest among the people. Being written by so well-
known an astronomer and author, it should have an even
wider interest than many other books of its kind. Much of it
is almost poetic in its imaginative descriptions, and the trans-
lation has been most successfully carried out. It is, however,
a pity that some of the illustrations do not follow suit. They
may be poetic and imaginative — many are of young ladies in
flimsy attire gazing at the hazy heavens — but they are neither
artistic nor descriptive. The " Contents " includes an " Intro-
duction " and an " Index," but neither of these desirable ad-
ditions appears in the print.

Popular Star Maps, by Comte de Miremont, F.R.A.S. (G. Philip

and Son ; price los. 5d. net.) These maps, with an introduction
to explain the principle employed in projecting them, short
account of '• Star Nomenclature," and lists of stars shown in
the maps, both in alphabetical order and in order of Right
Ascension, certainly form " a rapid and easy method of finding
the principal stars." On the other hand, this work forms a
somewhat bulk}- and elaborate apparatus for so simple a
requirement. Ten large plates are given, in which the white
stars stand out well on a dark blue ground, each with its key
map. Yet only the brightest stars are depicted, with but few
smaller than the 3rd magnitude. The constellations are thus
distinctly portrayed for the novice in astronomy, but for those
seeking more detail there is little information.

Chemistry in Daily Life, translated from the German of Dr.
Lassar Cohn by M. M. Pattison Muir, M.A. (Grevel and Co.;
price, 5s.). This is the third edition of a cousre of thoroughly
practical lectures, which should be widely read as giving a most
necessary addition to the education of the average Englishman.
It would be hard to be.at this little work for simplicity and
clearness of language and great scope of its teachings. The
latter may be made evident from a glance at the table of con-
tents, which includes: Analysis of air, breathing, combustion,
matches, candles, oils, petroleum, coal gas, incandescent gas
lights, electric furnace, food of plants, manures, food of men
and animals, diets, digestion, wines, explosions, fabrics, leather,
dyeing, painting, inks, acids, soaps, glass, bricks, photography,
X-rays, metals and alloys, and many other items. It must be
acknowledged that to have some scientific knowledge on all
those every-day subjects is both of great interest and un-
doubted utility, and a man who can pack the information con-
tained in this book into his brain will, in our opinion, be of far

KNOWLEDGE c>;- SCIENTIFIC NEWS.

[April, 1Q05.

more practical use in the world than he who has devoted the same
amount of time to a study of Greek. We commend the book
especially to school-masters and others interested in the educa-
tion of boys and young men, but none the less do we advise all
those who are not well up in these subjects to dip into the
book, after which their interest is sure to be aroused, and the
work read from cover to cover.

Remarkable Comets, by W. T. Lynn ; 12th Edition, Revised.
(Sampson Lo*-. Marston, and Co., Limited; London, 1905;
p.p. 46; price 6d.K Ojr astronomical readers are. no doubt,
acquainted with ttiis concise summarj' of the more interesting
facts in the history of cometary astronomy, and the present
edition, the twelfth, brings the account up to date. .'\s in
former editions the author restricts himself to the appearance
and reappearance of comets and their periodicities, and only
refers in a very brief manner to the relationship between
comets and meteor-swarms. The physical characteristics are,
as usual, almost neglected, lying outside the scope of the
survey. As the book is intended as a handy book of reference
to comets which m.iy be considered remarkable, its value would
be very much enhanced if, in future editions, a brief biblio-
graphy were added at the end. This would most certainly
assist those who wish to learn more about comets than that
which is contained in these pages, and would be very etficiently
done if compiled by the author of this excellent little treatise.

A Revised System of School Teaching, by Richard Chichester
(H. J. Glaisher; is. net). This is a pamphlet describing a
new system which might be adopted in schools. The
idea is founded upon the fact that " so often a boy, on
reaching a high class, being asked a comparatively simple
question, answers that he never learnt it " (presumably mean-
ing the answer). When such an occurrence is frequent, re-
form is certainly needed, but we should have thought it exposed
a fault in the detail of teaching rather than in the principle.
An idea well worthy of consideration is here suggested, which
is that, instead of boys being placed in one " form " or " class "
for all subjects, " DiWsions " should be formed for instruction
in each particular subject. All schoolmasters should read
this pamphlet, which may suggest to them some useful
wrinkles.

A List of English Clubs (or 1905, by E. C. Austen Leigh.
M.A. iSpottiswoode and Co.), will often be found of great use,
containing as it does not only details of all the London and
Provincial Clubs, but also those of English Clubs all over the
world, with membership, subscriptions, &c.

China Decoration and Repair, by Rev. F. C. Lambert (Dawbarn
and Ward : 6d.i, h a us«-ful little guide, but contains some
very inartistic designs.

The Children's Book of Moral Lessons, by F. J. Gould (Watts
and Co. ; price 6d.). The mor.il instiuction of children is too
frequently sadly neglected, and fiiblical History supposed to
suffice in this respect. The little work before us is an attempt
to impart such moral instruction under the guise of short
anecdotes.

Williams and Norgate's International Book Circular is
practically a bibliographical risumc of the world's best literary
productions in all branches of science and learning published
during the last few weeks, and as such will be found of great
value to students of science.

How to Build a Uthe. By A. W. Burford, A.M.I.C.E.
(Dawbarn and Ward), price 6d. net. (cloth is.), forms No. 9 of
the series of " Ctility " Practical Handbooks, some of which
we have already noticed. To build up a lathe from the raw
materials is instructive as well as being a cheap means of
obtaining a valuable possession. The instiuctions herein
given are very pr.-ictical, and a number of diagrams add to the
explanations in the text.

Lessons In Experimental and Practical Heometry. By H. S.
Hall, M.A., aiiJ l'. H. Stevens, M..\. (Macmillan), price is. 6d.
It is perhaps quite sound, though not altogether in keeping
with practice, " to give to a young pupil clear mental pictures "
of geometrical principles. To graphically explain what is
meant by lines, planes, angles, and all the other constituents,
the consideration of which go to make up geometry, is the
object of this little book. The idea is well carried out, and we
can confidently recommend this brochure to teachers of
elementary Geometry.

An Improvement in the
WimsKurst Machine.

Bv Charles K. I3e.\il\.\l

M.ANV years ago the late Mr. Wimshurst established the
fact that the electric influence machine which he in-
vented will work without the tinfoil sectors if large
brushes are used and if the varnish on the plain plates
is new. Under such conditions the machine is not
only sclf-cxciting, but the sparks arc e\cn longer than
when sectors of tinfoil are present. The reason for
the increase in spark-length is no doubt the greater
immunity from leakage. On the same, or, rather, the
converse principle, the increase of the number of
sectors diminishes the length of spark on a Wimshurst
by increasing the leakage. It is obviously inconvenient
to be constantly renewing the varnish on the glass
plates, so that the sectorless Wimshurst, though
interesting for exhibition as a class-room experiment,
is not adapted for practical work. By a simple ex-
pedient, however, the efficiency of the machine may be
increased and the required immunity from leakage re-
duced to a minimum without altogether doing away
with the sectors and rendering the self-excitement de-
pendent on the condition of the varnish. The way to
do this is to make every alternate sector of a semi-
conducting substance instead of tinfoil. Thin white
card seems to answer best. The cardboard sectors
may be larger than the intermediate tinfoil sectors.
The only reason why cardboard alone cannot be used
is that self-excitement is not assured, espcciall)' in very
dry weather. Very narrow sectors of tinfoil between
the card sectors will ensure the self-excitement, and as
soon as the potential increases, the semi-conducting
card acts fully as efficiently as metal, with the ad-
vantage that there is considerably less leakage and a
longer spark. The arrangement is equally efficient in
all sorts of atmospheric conditions, a small vulcanite-
disc machine of eight inches diameter responding
promptly after being left for some hours near :m open
window on a damp, foggy day, and giving at once
strong sparks of 2i inches length. The cardboard
sectors on each plate of this machine number 16, and a
narrow tinfoil strip is placed between each two. The
cardboard should be .-ittachcd firmly with strong glue,
the corners of the sectors being carefully rounded with
scissors before they are fixed to the plate. Woiking
the machine at full strain, with the dischargers wide
apart, in the dark, its immunity from loss by leakage is
at once apparent.

Acetylene as an Explosive.

M. fiiTKDRAS has been experimenting in Paris willi
acetylene as an explosive. The carbide is granulated
and charged in a special form of cartridge, consisting
of an iron-cvlinder, in Ihe bottom of which the c.irbide
is placed. .Above this is stretched a membrane, and
the top is filled with water. .\ rod is .so fixed in the
cartridge, that when its end is struck it pierces a hole
in the membrane, which lets the water on to the car-
bide, and acetylene gas is formed. The charge is fired
bv an electric fuse inside the cartridge.

April, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

Photography.

Pure arvd Applied.

By Chapman Jones, F.I.C, F.C.S., &c.

Toning with ferricyanides. — It is very desirable, at least
for the serious worker, to know exactly what chemical
changes take place during photographic operations, so
that the operations may be intelligently controlled and
the character of the product understood. It was there-
fore with a pleasurable expectancy that I read a few
weeks ago a communication from Messrs. A. and L.
Lumifere and A. Seyewetz on the composition of the
resulting image when a silver image is toned by means
of a solution of potassium ferricyanide mixed with either
a ferric, copper, or uranium salt. But it is with a feeling
of disappointment that I refer to the paper, for the authors
appear to have done little more than begin to find the
difficulties of the investigation. They show that when
finely divided metallic silver is acted on by a solution of
potassium ferricyanide, the silver does not simply attach
itself to the ferricyanide to form a double ferrocyanide,
thus- KjFeCys + Ag = KjAgFeCyg,

but that two salts are formed,

4 KjFeCye + 4 Ag = Ag^FeCye + 3 K^FeCye,
and that the potassium ferrocyanide may be washed
away, leaving the silver ferrocyanide. But when the
metallic silver is suspended in a gelatine film, as it is in
an ordinary developed image, they get a quite different
result by the action of potassium ferricyanide upon it. The
product then contains about twice as much iron as it
ought in proportion to the silver, after allowing for a very
small quantity of potassium which appears to be due to in-
complete washing. The presence of this extraordinary pro-
portion of iron (or deficiency of silver) remains a mystery.
When the ferricyanide of potassium is mixed with
ferric citrate as in iron toning or blue toning, the ferric
ferricyanide produced might be expected to combine
with silver directly forming silver ferric ferrocyanide
(AgFe'^FeCye), or if the potassium ferricyanide first
forms silver ferrocyanide as shown above and this reacts
with the ferric citrate, the silver might be entirely replaced
by iron and Prussian blue result (Fe^(FeCyf,),). But the
analysis of the product shows about five times as much
silver in proportion to the iron as represented by the first
formula. Probably a large amount of the silver in the
original image is unattacked.

When a copper toning solution is used we might
similarly expect to get either a double ferrocyanide of
copper and silver (Cu3Ag(FeCyo),) or merely ferrocyanide
of copper (Cu.FeCyo), a chocolate coloured substance to
which the colour produced on toning is generally supposed
to be due. A considerable quantity of silver was found
but the proportion of iron was nearly double that required
according to either formula. The approximately double
proportion of iron in this case, and also when the simple
potassium ferricyanide acts on finely divided silver in
gelatine, seem to point to a reaction that would repay
investigation.

Variations in Platinum Printing. — The platinum process
has many advantages, the chief of which are the per-
manency and the beauty of the results that it furnishes.
But to let well alone is not the nature of photographers,
and it is too often the case that those who try to im-
prove processes have only an empirical knowledge of
them, and know nothing about the suggestions that they
make and the modifications that they propose, except
that the prints they get are different from ordinary'prints.

The methods initiated by such workers must always
be unsafe until they have been properly investigated.

The image in a platinum print consists of metallic
platinum, and therefore it can only be affected by adding
something to it. Many methods of toning, and so on,
have been suggested, but they all, except perhaps one
in which gold is used, consist in depositing upon the
image substances that cannot be compared with platinum
for permanency. No reliance can be placed upon such
compound images, and it is not right to call them platinum
prints, for the great advantage of platinum, itsunchange-
ableness, has been compromised. By adding a small
proportion of certain salts, especially salts of mercury,
to the mixture with which the paper is coated, or, less
advantageously, to the developing solution, the colour of
the deposited platinum may be modified to a warmer
tint. This applies particularly to hot development.
Here also the image consists, I believe, of pure platinum,
for it behaves as if it were so, and neither metallic
mercury nor mercurous chloride can exist in contact
with the platinum salt without immediately depositing
metallic platinum. The paper supplied commercially
for sepia prints gives images that seem to be as un-
changeable as the ordinary black platinum image. But
suggestions have been made and formula; given for
adding comparatively large quantities of extraneous
salts to the coating solution or the developing solution,
and there is practically no doubt that in many of these
the limit of safety has been passed and the image is not
platinum and not permanent. I belie\ethatitmay betruly
stated that if the image is affected by any reagent that
the paper it rests on will withstand, it is not a genuine
platinum print. Such reagents as hydrochloric acid,
chlorine water, and potassium cyanide may be used.

Received. — The Thornton-Pickard Company send their
new catalogue, in which the important novelties described
are the " Royal " shutter, similar to their " Standard " " time
and instantaneous " shutter, but with the mechanism inside
the case, and so protected from dust and other damage ;
and a bellows-form of ball compressor, which is better than
the simple ball in that it delivers always the same volume
of air, and thus contributes to the uniform working of the
time exposure valve. A prize competition is announced.

Mr. William Hume, of i, Lothian Street, Edinburgh,
pubhshes a list of his enlarging apparatus in their many
varieties, and with almost innumerable accessories,
including also valuable suggestions as to the selection
and using of them ; indeed, it is a guide book as well as
a list. The application of modern illuminants such as
acetylene, arc lamps, Nernst lamps, and incandescent gas,
as well as oil lamps and the limelight, are fully dealt
with. Mr. Hume was the first to use the word " canti-
lever " in this connection as a " selling name," and has
specialised in enlarging apparatus since the year 1888.

Messrs. Taylor, Taylor, and Hobson, of Leicester,
have just published their new catalogue of lenses, &c.,
which includes other items of information likely to be
useful to photographers, and will be sent to any applicant
who mentions the name of this journal. They have
introduced two new series of Cooke lenses. Series II. are
portrait lenses 'with a maximum aperture of f 4"5, and
will give sharp or softened definition at will. Series IV.
have an aperture of f 5-6, and are specially suitable for
high-speed shutter work in general.

Messrs. Kodak are again inviting competition for
several valuable money prizes for work done with Kodak
apparatus and materials. About one half are reserved
for those who have not yet won a prize in such competi-
tions. Entries will be received up to the end of September,
and full particulars may be obtained from the Company.

KNOWLEDGE & SCIENTIFIC NEWS.

[April, 1905.

Coniiided I'll F. Shili.ington- Scales, f.k.m s.

Fibrous Constituents
of Paper.

{Continued from Page 68.)

Chlor-zin'C iodine gives a characteristic bluish violet
reaction with celhilose, becoming reddish-brown to
claret-coloured for rag and similar fibres, and light to
dark yellow for lignified fibres. We have thus a ready
means of distinguishing the fibres by their colour re-
actions alone, which we may summarise as follows : —
Linen, cotton, hemp, reddish-brown to claret; esparto,
straw, and chemical wood-pulp, bluish-violet; mechani-
cal wood-pulp and jute, yellow. Jute may be more blue
than yellow, whilst manilla hemp — an entirely different
fibre to hemp itself — will be blue rather than red.

With polarized light the fibres also behave
differently. The nicols being crossed so that the field
is dark, it will be seen that linen and hemp give a
brilliant play of colours, especially if the microscope
has a stage which can be rotated; jute gives these
colours in a rather less degree, cotton or wool still less;
whilst esparto, straw, and wood-pulp are colourless.
It will be observed also that the various structural
details of the fibres are brought out very clearly by
this method, and this is of service in making the final
examination, as it will be observed that neither the
chlor-zinc iodide differentiation nor that with polarized
light are necessarily quite determinative.

The examination of the structural differences of the
various fibres is, however, the most difficult of all, and
requires more experience than is apparent at first sight,
not a little of the difficulty being due to the rough treat-
ment the fibres have undergone as already mentioned.
A study of the accompanying illustrations will assist the
reader in following the description.

Cotton shows flat, ribbon-like fibres with a large
lumen about two-thirds of its total diameter, so that
the cylinder, being weak, has collapsed in places and
thus given rise to a sort of spiral twist which forms the
most characteristic distinction of this fibre. It should
be noted, however, that the boiling in caustic .soda
largely counteracts this twist, as does the breaking up
in process of manufacture, so that the absence of the
twisted appearance does not necessarily decide the
question. The fibres also show fine, lattice-like mark-
ings, and it will be observed that they are free from
thickening or knots. The ends are often laminated.
Taken altogether, the wide lumen, the spiral twist, the
markings, and the freedom from knots form charac-
teristic features which make cotton one of the easiest
fibres to distinguish.

Linen and hemp are so much alike that it is almost

impossible to distinguish them, but they are not often
found in the same classes of paper, or where identifica-
tion and separation from each other is necessary. The
fibres are smaller than those of cotton — about half as
thick — and they have a very small lumen, so small that
it often appears little more than a narrow central line.
In places, however, the pressure which the fibre has
undergone during pulping may have flattened out the
central canal so that it bears a strong resemblance to a
jute fibre or even to cotton. The frequent thickening
into knots is very characteristic, but otherwise the fibre
is fairly uniform in thickness, and cylindrical. There
are also numerous dark cross lines which come out well
under polarized light. The ends are often drawn out
into fine fibrillae.

esporfo

Jute fibres have a peculiarly uneven appearance.
The wall is thick and thin in places, and the central
canal varies prf>porfionately in width from a thin line
to a canal as broad as that of cotton, and all these
changes may be observed without moving the slide.
They also show cross-striations and knots, but less
frequently than linen or hemp. Jute is a very intract-
able fibre, and accordingly the fibres will be often ob-
served sticking together in parallel bundles. It is most
difficult to bleach, and its use is, therefore, almost en-
tirely confined to coarse papers.

Straw fibres are smooth and even, cylindrical, uni-
form in diameter, and with a central canal of varying
size, but at intervals knots appear. Striations are

April, 1905.

KNOWLEDGE & SCIENTIFIC NEWS.

likewise seen. A certain number of flat, oblong cells
from the parenchyma are always found in papers made
from straw, and ring-like portions of spiral and annular
vessels may also be found, but the most characteristic
features are the numbers of finely-serrated epidermal
cells, which are thick-walled with jagged edges. They
must, however, not be confused with the somewhat
similar cells in esparto.

[To be Concluded.)

R.oya.1 Microscopica.1 Society.

February 15, at 20, Hanover Square, the President,
Dr. Dukinfield H. Scott, F.R.S., in the chair, the
Secretary read Mr. Finlayson's description of the Ashe-
Finlayson Comparascope. This is an apparatus designed
to show two images side by side in the microscope
for comparison, and consists of the attachment to any
ordinary microscope of a second objective, stage, and
illuminating apparatus, placed on one side at right angles
to the optical axis of the microscope. On the nosepiece
of the latter is screwed a short tube with a circular
aperture at one side, and containing a reflector extending
half-way across, placed at an angle of 45° to the axis
of the tube. The subsidiary apparatus is applied at this
aperture, the reflector thus transmitting the image of the
second slide to the eye-piece. The reflector utilises half
the diameter of the tube, the other half serving for the
passage of light from the primary objective direct to the
eyepiece. A diaphragm or division plate extends up
the tube from the reflector almost to the eyepiece to pre-
vent overlapping of the images, which appear together as
two semicircles, equally distinct. Mr. C. Beck exhibited
a new optical bench for microscopic illumination, photo-
micrography, micro and lantern projection, and a large
micro-photographic and enlarging camera, both bench
and camera being mounted on special tables. Mr. J. E.
Stead, F.R.S., delivered the first part of a lecture on
"Practical Micro- Metallurgy." He alluded to Dr.
Sorby's pioneer work on this subject some forty years
ago. Dr. Sorby's method was very simple, a small
piece of metal being ground down to a flat surface, and
finally polished on various grades of emery-paper, finish-
ing with rouge parchment. This method was still adopted,
but by means of special machinery the process was
reduced from two or three hours to five minutes. Mr.
Stead described this machinery, and explained the various
processes of cutting, grinding, and polishing, also the
different methods of preparing the polished surface so as
to render the structure visible, their mounting, and also
suitable illumination. The lecture was illustrated both
by lantern slides and by actual specimens, the beautiful
colours due to heating being shown in a quite novel way.

The Quekett Microscopica.1 Club.

The 42otli ordinary meeting, which was also the
annual meeting, was held on February 17 at 20, Hanover
Square, the President, Dr. E. J. Spitta, V.P.R.A.S., in
the chair. The annual report and balance sheet were
read, and gave evidence of a larger membership and im-
proved financial position as compared with the previous
year, the number of new members elected during the
year being 50, whilst the total membership amounted to
382. Dr. E. J. Spitta was re-elected President, and all
the other officers were also re-elected, except that Mr.
J. J. Vezey, F.R.M.S., was elected as a Vice-President
instead of Mr. George Massee, F.L.S., who retires. Mr.
A. D. Michael, F.L.S., delivered the annual address,

dealing with " Improvements Effected in Modern Objec-
tives," with special reference to the various corrections
necessary for both objectives and eyepieces, the use of
Jena glasses, and their results, as evidenced in the
apochromatic lenses and the improvement in achromatic
lenses, which justify their description under a new name as
semi-apochromatic.

Notes and Queries.

Bausch and Lomb's Portable Microscope.

With reference to my notice last month of this microscope,
and my remark that in the instrument sent me the condenser
did not quite come into focus, I am informed that this is pur-
posely put out of focus to prevent the upper and auxiliary
diaphragm being damaged by accidentally coming in contact
with the condenser top, and that by means of a screw thread
in the condenser mount the optical part can, if required, be
brought level with the stage. But as it is a primary require-
ment that a condenser should readily focus, it seems to me
that this is an undeserved concession to careless workers, the
more so as the upper diaphragm and the condenser are not
generally used together. A preferable way, if the upper
diaphragm is retained, would be to alter the construction of
the condenser so as to give it a slightly longer focus. In the
meantime, it is only fair to Messrs. Bausch and Lorab to add
this explanation.

C. A. Wineku'orth {Brighton). — I think that from your de-
scription there can be little doubt that what you have observed
was merely an amceba undergoing division. Under any cir-
cumstances, they could not be bacteria.

Dr. ir. /. Blanch (Si. Kitts). — Your question touches on a
matter which has exercised many minds, but only through a
misapprehension of the true principles involved. Assuming
that you could have a film that showed no grain under the
highest magnification, you could, of course, easily enough
magnify an image photographically impressed upon such a
film, and repeat the process as often as you wished, but in
each stage you would be merely magnifying what existed on
the original film. Now what you had upon the first film de-
pends on the aperture of the lens through which the photo-
graph was taken — in other words, the aperture of the lens
governs its resolution, and you would get no more detail by
subsequent magnification. So that the mere fact that you
enlarged a fine, but perfectly distinct, line into a broad and
coarse one would be useless. The experiments you allude to
tend to make fine detail resolved by the objective more evident
to the eye, but that does not affect the issue.

Miss F. Elliot (Staines).--! much regret that pressure on
my space prevented my answering your query last month.
Hircinia variabilis is a horny sponge, very variable in shape,
as its name implies. The simplest forms are incrusting. hori-
zontally expanded, and more or less cake-shaped. It often
grows more vertically than horizontally, and attains an irregular
globose form. Sometimes, owing to uneven rapidity of growth,
rugose, tubercular, or even lobose forms are produced, but in
any case the sponge appears as a crust from the upper surface
of which these processes arise. The crust is sometimes much
curved, raised in the centre, and attached at the margins only.
The surface is covered with conuli, the oscula are large and
conspicuous, and the colour light to dark brown in the living
state. The sponge consists of slightly fascicular main fibres,
joined by connecting fibres which form a mesh or net-work.
There are several varieties, several of which are found in the
Adriatic, and it is found also in the Pacific Islands, India,
.Australia, Jamaica, Florida, &c. For the hfe history of sponges
I am afraid I must refer you to any good book on Zoology,
and unless I know more exactly what you wish specially to
examine I can scarcely advise you as to methods. You might
begin with a little dissecting, and then cut sections by hand.
'• Knowledge " is the only English journal which deals
systematicallv with Microscopy, and I regret with you that the
space at my disposal is not larger, but I will gladly give you
any assistance in my power.

[Communications and enquiries on Microscopical matters are invited,
and should be addressed to F. Shillington Scabs, "Jersey,"
St. Barnabas Road, Cambridge.]

KNOWLEDGE c^ cSCIEXTIFIC NEWS.

[April, 1905.

The Face of the Sky for April

By W. Shackleton, F.R..\.S.

The Sun. — On the ist the Sun rises at 5.38, and sets at
6.31 ; on the 30th he rises at 4.37, and sets at 7.19. The
equation of time is negligible on the i6th. Sunspotsand
facukt-are usually conspicuous on the solar disc, marking
a return to nia.ximum activity, whilst prominences also
continue to be numerous.

For plotting the positions of spots, &c., the following
table gives the necessary data : —

Date.

Axis inclined from N.
point.

Equator N. of
Centre of disc.

April I .. 26''23'W. 6° 28'
„ II .. 26" 23' W. 5° 47'

., 21 .. 25° 45' W. 4° 58'
May I .. 24' 20' W. 4° 0'

The Moon : —

Date.

Phases.

H. M.

April 4 • •
,. 12 ..
.. 19 ••
.. 26 ..

• New Moon
5 First Quarter

0 Full Moon

1 Last Quarter

11 23 p.m.
9 41 P-m-
I 38 p.m.

II 14 a.m.

April 4 ..
,. 18 ..

Apogee
Perigee

9 0 a.m.
10 6 p.m.

OccuLTATiONS. — The only bright star occulted during
convenient hours is 7 Virginis (mag. 4-0) at 8.18 p.m. on
the 17th.

The Planets. — -Mercury is an evening star in Aries,
being at the most favourable eastern elongation of the
year on the 4th, when he sets at 8.30 p.m. He should
be looked for immediately after sunset, nearly due west
and rather low down. On the evening of the 6th he is
7* N. of the thin crescent moon. The planet is in
inferior conjunction with the Sun on the 23rd.

Venus continues to be a brilliant object in the evening
sky during the earlier part of the month, and sets about
10.10 p.m. on the ist. The planet stts earlier each day,
and is in conjunction with the Sun on the 27th. As seen
in the telescope, the planet exhibits a crescent which is
thinning out but increasing in apparent diameter ; on the
15th, 0-05 of the disc is illuminated, the diameter being 55".

Mars is not in a favourable position for observation,
being situated low down in Libra. About the middle
of the month he rises at 9.30 p.m. and comes to the
meridian at 1.50 a.m.

Jupiter is practically out of range for observation,
setting at 8.30 p.m. on the 7th ; from this date to June
1st the satellites are invisible, as the planet appears too
near the Sun. The moon is near Jupiter on the evening
of the 6th.

Saturn is a morning star in Aquarius, rising about
3.45 a.m. near the middle of the month.

Uranus does not rise until after midnight ; he is situated
low down in Sagittarius.

Neptune is on the meridian before sunset, but is ob-
servable in the west until midnight, as he sets about
I a.m. on the 15th. The planet is near ^ Geminorum,
and can most readily be found by reference to that star.

Right Ascension. Declination.

Neptune (.\pril 15). e*" 24"" 16* .. N. 22° 2i' 51"

II Geminorum . . e^ 17"' 13' . . N. 22° 33' 38"

Meteor Showers: —

Date.

Radiant.

Name.

Characteristics.

R.A.

Dec.

Apr. 1 7-May 1
,, 20-21
,, 20-22
.. 30

h. m.

16 0

17 24

18 4

19 24

+ 47'
+ 30°
+ 33°
+ 59°

T Herculids
jT Herculids
Ly rid Shower

0 Draconis

Small ; short.
Swift ; bl. white.
Swift.
Kither slow.

Minima of Algol may be observed on the 9th at 11. 5
p.m., and on the 12th at 7.54 p.m.

Telescopic Objects : —

Double Stars. — y Virginis, XII.'' 37™, S. o' 54', mags.
3, 3 ; separation 5"-9. Binary system ; both components
are yellow, though one is of a deeper hue than the other.
An eyepiece of a power of 30 or 40 is required on a 3-in.
to efiect separation.

IT Bootis, XIV.'' 36"", N. 16° 53 ', mags. 4, 6 ; separa-
tion 6". Requires a power of about 40.

f Bootis, XIV.'' 41'", N. 27° 30', mags. 3, 6i; separa-
tion 2"'7. Very pretty double, with good colour contrast,
the brighter component being yellow, the other blue
green.

f Bootis, XIV.'' 47"", N. 19° 31', mags. 5, 7; separa-
tion, 2"-5. Binary ; one component being orange, the
other purple.

Clusters.— M 3 (Canes Venatici), XIII." 38-", N. 28"
48'. This object, though really a globular cluster of
myriads of small stars, appears more like a nebula in
small telescopes. It is situated between Cor Caroli and
Arcturus, but rather nearer the latter.

Royal Institltion. — The following are the Lecture
Arrangements at the Royal Institution, before Easter: — A
Christinas Course of Lectures (eNperimcntaliy illustrated and
adapted to a juvenile auditory) on Ancient and Modern
Methods of Measurint; Time, by Mr. Henry Cunynghamc;
Professor L. C. Miall, Fnllcrian Professor of PliysioloKy, K.I.,
Si.x Lectures on Adaptation and History in the Structure and
Life of Animals ; Professor Karl i'l'arson, Tbrci- Lectures on
Some Recent Hiometric Studies; Professor W. V.. Dalby, Two
Lectures on Engineering; Mr. A. H. Savage Landor, Two
Lectures on E.\ploration in the Philippines; Mr. Churton
Collins, Two Lectures on (1) The Religion of Shakespeare,
[z) The Philosophy and Significance of "The Tempest";
Professor W. Schlich.Two Lectures on Forestry in the British
ICmpire ; Mr. J. J. IL Teall,Two Lectures on Recent Work of
the Geological Survey ; Professor H. H. Turner, Three Lec-
tures on Recent Astronomical Progress; Professor R. Meldo'a,
Two Lectures on Synthetic Chemistry (Experimental); Sir
Alexander Mackenzie, Three Lectures on the Hoheniian
School of Music (with Musical Illustrations); Mr. 1). G.
Hogarth, Two Lectures on Archeology; Professor J. J.
Thomson, Three Lectures on Electrical Properties of Radio-
active Substances; and the Rt. Hon. Lord R.iyleigh, Three
Lectures on Some Controverted Questions of Optics. The
I'riday Evening Meetings will begin on Janu.iry 20, when a
Discourse will be delivered l)y Professor Sir James Dew.ir on
New Low Temperature Phenomena; succeeding Discourses
will probably be given by Dr. E. A. Wilson, Mr. Cecil Smith,
Mr. J. W. Gordon, Professor H. Marshall Ward, Chevalier G.
Marconi, Professor J. J. Thomson, Sir Squire Bancroft, Pro-
fessor G. H. Bryan, Professor J. Wright, Professor T. C.
Allbutt, the Rt. Hon. Lord Kayleigh, and other gentlemen.

KDomledge & Seieotlfle flems

A MONTHLY JOURNAL OF SCIENCE.

Conducted by MAJOR B. BADEN-POWELL and E. S. GREW, M.A.

Vol. II. No. 5.

[new series.]

MAY, 1905.

Entered at -i
Stationers' Hall.J

SIXPENCE.

CONTENTS.— See Page VIl.

Modern Cosmogonies.

XIII. — Life qls the Ovitcome.^

By Miss Agnes M. Clerke, Hon. Mcmbsr R.A.S.

The making of world's, we are assured, was not pur-
poseless ; and its most obvious purpose to our minds is
the preparation of suitable abodes for organic life. No
other seems of comparable importance ; no other, indeed,
comes within the full grasp of our apprehensive intelli-
gence. Its limitations, however, must not be forgotten.
The human standpoint is not the only one from which
the sum of things may be surveyed ; and although we be
unable to quit it, we can still admit that the view obtain-
able from it is probably not all-embracing. We only,
then, know with certainty that the end which appears to
us supreme has, in one case, been successfully attained ;
how far it was sought to be compassed elsewhere must
always remain a matter of speculation.

On our own globe, the presence of life is none the less
mysterious for being profuse and familiar. W'e can
trace the strange history of its slow unfolding ; but the
secret of its initiation baffles our utmost scrutiny. The
cooled rind of a once molten globe serves as the stage
for the drama ; beneath it, primeval heat still reigns.
Temperature rises steadily with descent into the interior
of the earth ; at a depth of about two miles, it must reach
the boiling-point of water at the sea-level. This tem-
perature, which is absolutely prohibitive of vitality, was
formerly, beyond question, that of the surface. At some
long-past epoch, accordingly, our future oceans hung
suspended as a prodigious envelope of vapour above a
hot crust of slag and lava ; our teeming planet lay
barren ; it harboured no promise, no potency, no visible
possibility of life.

So it should have remained had the law of continuity
been rigidly enforced ; but there came a time for a new
beginning, and a new beginning was made. A momen-
tous alteration took place ; inert nature was quickened ;
what had been sterile became all at once fruitful ; an
immeasurable gulf was bridged, and movement was
started along an endless line of advance. That the
advance was set on foot and directed by an intelligent
Will is the only inference derivable from a rational survey
of the known facts.

* Continwd from February.

Life can be studied in its manifestations, not in itself.
Attempts to define it have served only to show our in-
ability to " lift the painted veil." W^e can, however, see
that its presence is attended by characteristic effects,
brought about in harmony with the laws or inorganic
nature, although not in blind submission to them. Their
operation is somehow restrained, and appears to be
subtly though securely guided towards determinate ends
prescribed by the vital needs of each animal or plant.
This modifying principle unmistakably regulates the
economy of every living organism ; the cessation of its
activity means death.

Science has made no progress towards solving the
enigma of vitality. Its evasiveness becomes, on the
contrary, more apparent as enquiry is rendered more
e.xact. Under a laxer discipline of thought the contrast
between life and death seemed less glaring. It was
easily taken for granted that creeping things were
engendered by corruption, aid being invoked if required
from the virtus codestis of the eighth sphere. Thus, the
birth of mice from damp earth was, in the ninth century,
held to be signified by the word mus (= hu-mus);* and
\an Helmont, at the height of the revival of learning,
published without misgiving a recipe for the creation of
the same animals, f Yet there was already better know-
ledge to be had for the asking ; and Francesco Redi, in
1668, crystallised Harvey's opinion in the celebrated
maxim, " Omne vivum ex vivn." Its truth is incontro-
vertible. Challenged and tested again and again, it has
as often been vindicated, and may now be said to stand
outside the range of debate. " That life is an antecedent
to life," Lord Kelvin declared in 1871, " seems to me as
sure a teaching of science as the law of gravitation."!

But the succession is not easy to start within the term^
of a strictly uniformitarian convention. The expedient
is tempting, if scarcely satisfactory, of demanding from
the past what we dare not claim from the present. Two
and a half millenniums ago, it was already in vogue.
Herodotus dismisses a genealogical embarrassment with
the remark ; yhoiTo S'av Tvar iv ru iiaKsu x^'"''^t which may b-;
freely translated, " In the long run of time, anything
may happen." Conditions, we are apt to think,
may have been more elastic long ago. The proven
impossibility of to-day becomes vaguely thinkable seen
through the mist of uncounted yesterdays. " If it were
given to me," Professor Huxley said," " to look beyond
the abyss of geologically recorded time to the still more
remote period when the earth was passing through
physical and chemical conditions which it can no more see

* Hewitt, Problems of the Age, p. 105.

t Pasteur, Annales dc Chimie el de Physique, t. XLIV., p. G, 1S62.

; Popular Lectures and Addresses, Vol. II., p. igS.

H Report Brit. Ass., 1870, p. 84.

KNO\YLEDGE cV SCIENTIFIC NEWS.

[May, 1905.

again than a man can recall his infancy, I should expect
to be a witness of the evolution of living protoplasm
from non living matter." To these first vital compounds,
he attributed a fungoid nature and mode of growth ; and
the choice deprived his speculation of any plausibility
that might otherwise have belonged to it. Fungi are not
self-supp>orting ; they cannot supply themselves with
nourishment from the raw materials of the mineral
world ; they depend "upon the hospitality of differently
organised beings. They were then certainly not among
" the first mercies of nature.'" Mr. Herbert Spencer, too,
was inclined to regard spontaneous generation as a
superannuated process. The leap from the non-vital to
the vital, now admittedly impracticable, might have been
taken, it seemed to him. when " the heat of the earth's
surface was falling through those ranges of temperature
at which the higher organic compounds are unstable."
But the " reason why " is to seek. A sterilised solution
is precisely one which has cooled from a high thermal
grade ; a baked brick is similarly circumstanced. Why
should the appearance of life in primeval times have
been favoured by a state of things fatal to it here
and now ?

The essence of the biological crux resides in " proto-
plasm." The word was coined by Von Mohl in 1846
with the object of emphasising the importance of the
substance signified, which indeed forms the bulk of every
organism, animal and vegetable, man, mushroom, and
amreba. Huxley rightly termed it " the physical basis of
life." adding, however, the infelicitous conjecture that its
production might have been one of the lucky hits
of nature. It would have been a hit of incalculable
moment, but of incalculable improbability. " Odds
beyond arithmetic " were against that particular throw
coming out of the Lucretian dice-box. The " primal
slime" (to use Oken's phrase) is composed of oxygen,
nitrogen, hydrogen, and carbon, with minute percen-
tages of phosphates and other salts. But these con-
stituents are put together in a highly artificial
manner. Eight or nine hundred elementary atoms, in
fact, go to the making of one molecule of protoplasm,
forming a structure of extreme complexity, most deli-
cately balanced, and eminently unstable. It results,
accordingly, from the employment of specially directed
forces, and stores, for the benefit of the producing
organism, the energy expended in its construction. Left
to itself, it promptly goes to pieces, and yields back its
component particles to their native inorganic sphere.
The laws there ruling are in truth adverse to the exis-
tence of protoplasm ; abandoned to their unmitigated
action, it perishes. We should then as reasonably sup-
pose that in the geological past, rivers flowed uphill, as
that inorganic naturestumbled blindly upon this wonderful
postulate and product of life.

Professor Huxley affirmed life to be " a property of
protoplasm," the inevitable outcome of " the nature and
disposition of its molecules." And he sought to cover the
absurdity of the dictum by claiming as analogous a case
wholly disparate. Water, he argued, has qualities totally
unlike those of oxygen or hydrogen ; and protoplasm
may similarly, by mere intricacy of arrangement, and the
evoking of latent affinities, become endowed with the
transcendant powers connected with animated existence.
" What better philosophical status, then," he exclaimed,
" has vitality than aquosity ? "- " True," he added, " proto-
plasm can only be generated by protoplasm, in a manner
that evades our intelligence; but does any body quite
comprehend the modus operandi of an electric spark which

* CoUuttdEisays, Vol. I., p. 153.

traverses a mixture of oxygen and hydrogen ? " The
illustration, however, is inapt. The electric spark fulfils
no constructive function. It simply agitates the mole-
cules so as to bring their native affinities into play. It
acts like a mechanical blow on dynamite. Further,
water is a stable compound, because its formation is
attended by loss of energy, and the descent to a lower
plane gives permanence to its occupation. But proto-
plasm is, in this respect, the antitype of water. It needs
force for its composition ; water needs force for its decom-
position. Protoplasm needs force plus a suitable appa-
ratus : it can be turned out only by an artfully adapted
machine with a head of steam on. It is thus continually
manufactured by plants under the stimulus of light.
They supply the apparatus, sunbeams the energy. If
the supply is cut off, the machinery comes to a halt ;
protoplasm ceases to be generated ; the plant dies of
inanition.

Many German biologists find themselves compelled by
the impossibility of explaining vital activities in terms of
chemistry or physics, to associate protoplasm with some
kind of psychical activity. ■■ Individuality, at any rale,
implies an ultra-material principle; and it asserts itself
at the very base of the animal creation. An ama'ba is
the simplest of living beings. I'ormerly called the
"Proteus animalcule," it is "everything in turn, and
nothing long." It can be round or radiated, spherical or
lenticular, as momentary convenience prescribes. Organs
it has none ; its limbs are conspicuous by absence ; it is
"sans everything " that bnlongs to the ordinary outfit of
an animated creature. Vet such-like nucleated globules
of protoplasm have flourished exuberantly during count-
less ages. Adaptability ensured survival. Anamcrbais
at home in almost an)' environment. What it has not
ready-made, it can supply at a moment's notice. Out of
any part of its substance it can improvise feelers and
tentacles for the capture of its prey, as well as a stomach
for its digestion ; and thus effectively goes through the
full round of animal economy. Some varieties, too, are
noted builders. These Foraminifera have the faculty of
secreting carbonate of lime from sea-water ; and with it
they construct fairy dwellings, perforated in all directions
to allow of the protrusion of exploratory filaments.
I'"ossil-chambered shells of this type are extraordinarily
abundant. Their dense conglomeration in the chalk
elicited Buffon's exclamation that " the very dust had
been alive !"+ The calcain grassier of which Paris is
built mainly consists of them ; and to this day, in oceanic
depths, the materials of future- capitals are in course of
preparation by the monumental industry of these un-
pretending organisms.

Such as they are, they maintain an incomparable status.
Incomparable, for instance, as regards the water in which
they float. An amoilia incarnates a purpose ; it embodies
a spark of individual existence, unconsciously swaying
the powers of inorganic nature towards the ends of its
own well-being. The subordination is most real, though
profoundly mysterious. In the organic and the inorganic
worlds, the same laws hold good ; the same ultimate
atoms exert their preferences in each ; in neither is an
uncaused effect possible. A bullet can no more be fired
from a gun that has no charge than a man can lift a
finger without a corresponding outlay of food -products.
.Accordingly, while plants store and animals expend
energy, plants and animals are equally incompetent for

• Neameister, BcirachluneeK iiber das Westn der LebeHiencheinungen ,
1903.
f Owen, I'ala-oiilology, pp. 11,' 14.

1905.,

KNOWLEDGE & SCIENTIFIC NEWS.

its origination. What they can do is to appropriate and
specifically apply it ; and herein resides the essence of
life. " It would seem," Sir George Stokes wrote in
1893, ''■' " to be something of the nature of a directing
power, not counteracting the action of the physical forces.
but guiding them into a determined channel." What
the power is in itself it would be futile to seek to define.
We are only sure of its being extra-physical. Matter
cannot evolve a principle which disposes of it as its
master. Evolution means only the unfolding into self-
evidence of something already obscurely present. The
"latent process " (to use a Baconian term) of the hatch-
ing of an egg is typical and instructive. Yet it is not
the less recondite for being familiar. A concourse of
suns, indeed, fails to impress us with the unutterable
wonder of the " flower in the crannied wall " ap>js-
trophised by the last great poet of the nineteei th
century.

The two wide kingdoms of life lack a "scientific
frontier." The boundary-line is ill-marked and irregular.
So much so that a few naturalists have set up a neutral
zone, or no man's land, inhabited by creatures of mixed
or uncertain nature, by plant-animals, or zoophytes in
the literal sense of the word. But the expedient avails
to shelter ignorance rather than to advance knowledge.
For it seems probable that there is no organism so im
perfectly characterised as to be genuinely incapable of
giving a categorical answer to the question, " Under
which king, Bezonian ? " Fungi might, perhaps, on a
superficial view be taken for hybrids. They share the
nature of animals so far as to be unable to elaborate their
own food, while appearing in other respects to be
authentic vegetables. They are, in fact, parasites and
scavengers. Not the smallest reason exists for suppos-
ing them to constitute a genetic link between the two
chief hierarchies. These are, in all likelihood, funda-
mentally distinct. Only by a gratuitous hypothesis can
they be credited with a common ancestor. Each seeks
a different kind of perfection ; their ideals, so to speak,
follow divergent tracks. That the tracks were marked
out from the beginning, may be safely affirmed ; and this
implies radical separation. Plants came first, since
animals pre-suppose and imperatively require them ; the
antecedence having quite possibly been by a vast interval
of time. On this point, geological evidence, though in-
conclusive, is suggestive. The Laurentian beds, which
are among the very earliest stratified formations, contain
no recognisable fossils. They were once supposed to en-
shrine the remains of a lowly organism dubbed Eozoon
Canadense ; but the markings that simulated animal forms
are now known to be of mineral origin. Laurentian
graphite, on the other hand, occurs plentifully ; and
graphite may be described as coal at a more advanced
stage of mineralisation. Such deposits, we are led to
believe, consist of altered vegetable substances ; and it
seems to follow that these hoary rocks are the burying
ground of a profuse succession of virgin -forests. That
they flourished beneath the sea — were in fact composed
of algae — was the opinion of Professor Prestwich ; t and
it is not easily gainsaid.

Primitive animal life was unquestionably marine, and
the Huronian strata, which overlay the Laurentian,
afford traces of it in a few sponge-spicules, the cast of
an annelid, and such-like scanty leavings. Higher up,
the Cambrian series swarms with oceanic invertebrates;
fishes, the first tyre of vertebrates, came upon the scene

• afford Lectures, p. 46.
f Geology, Vol. II., p. 22.

in Silurian times ; and so, by a various and surprising
progression, life advanced through the ages, until the
ascending sequence culininated with a being cast in a
diviner mould, who walks the earth, even now, with face
uplifted to the stars.

" Natus homo est ; ilium mundi raelioris origo
Finxit in effigiem moderantura cuncta deorum."

In the vegetable kingdom, the vital law of develop-
ment has wrought with less conspicuous effect. The
superiority of recent to ancient floras is more significant
than striking. A tree-fern or a sigillaria bears compari-
son with an oak much better than a trilobite or a plesio-
saurus with an eagle, horse, or lion. The geological
variations of plants, however, have unmistakably tended
to make them more serviceable to man — more serviceable
to his material needs, and also more gratifying to his
aisthetic instincts. For him, flower petals were painted,
and perfumes distilled; for him, the grasses of the praiiie
laid up stores of sustaining nutriment ; in preparation
for his advent, choice fruits ripened and reddened under
Tertiary sunshine ; while the barren and sombre vegeta-
tion of the Carboniferous epoch had already done its
part by dying down into seams of coal for the eventual
supply of power for human industry and warmth for
human coinfort.

It would be an abuse of our readers' patience to discuss
the futile.conjecture of an extra-terrestrial origin for life
on our globe. The agency, in this connection, of germ-
laden aerolites was first invoked by Richter of Dresden ;
and Lord Kelvin gave currency to the notion by an inci-
dental reference to it in 1871 from the Presidential Chair
of the British Association. Its adoption would oblige
us to regard the denizens of our planet, fauna and flora
alike, as salvage from the wreck of some unknown world
in space. Cvedat Judaus ApcUa. To our minds, " all the
fables of the legend " appear more credible than the pre-
natal history of the primal organism implied by this
" wild surmise." Inquiry into tlie nature of the supposed
organism serves to draw closer the web of embarrass-
ment. The remarkable aridity of meteorites excludes
the possibility of its having been of aquatic habitat.
Members of the fungoid order are unsuited to act as
pioneers, owing to their helplessness in the matter of
commissariat ; and the spores of lichens or mosses could
scarcely be expected to survive the vicissitudes of such a
journey as they must have performed if meteor-borne to
terrestrial shores. The immigration hypothesis, more-
over, even if it were plausible, could not be made useful.
Difficulties do not vanish on being pushed into a corner ;
the problem of life is as formidable in one world as in
another ; we should not expect to find it easier to square
the circle in Mars than Deinostratos found it in Greece ;
matter, we are convinced, has no more ps} chical in-
itiative in the system of Arcturus than can be ascribed to
it in the system of the sun. Profitless conjectures may
then be dismissed ; they do not help us out of the slough
of intellectual impotence.

This need not indeed be absolute. The determination
to regard things mechanically alone renders them unin-
telligible. Science becomes unscientific when it refuses
to be guided by experience ; and we have the plainest
testimony of consciousness to the working in ourselves
of originative faculties independent of, and irrepressible
by, physical agencies. Here we hold the clue to the
labyrinth. The intimation conveyed is distinct of a
Power outside nature, continually and inscrutably acting
for order, elevation, and yivification.

KNOWLEDGE & SCIENTIFIC NEWS.

[May, 1505

Seeing BeneoLth the

WSlVCS.

By THE LATE Rev. J. M. Bacon.

A CURIOUS controversy arose fifty years ago concern-
ing the old fable of the " Dog and the Shadow," which
opened up the subject of vision through water. On
the one side Doctor Lardner maintained that the story,
" handed down through so many ages, diffused through
so many languages, and taught so universally in the
nursery and the school," of a dog being able to see in
water the reflection of himself and the meat in his
mouth, " was a most gross optical blunder." On the
other hand, critics were not found wanting who im-
plied that the fable only represented a fact which
ought to be familiar in all possessing ordinary ob-
servation. Thereupon the doctor retaliated with an
experiment of his own, the futility of which should
hardly need pointing out. He filled a basin with water,
and, placing it near an open window, looked down
upon it from a height of five feet, and saw no trace of
his learned countenance therein.

Now, had the doctor simply gone to his water butt,
the water within which we will suppose to be clear
and not too near the top, and looked in, being careful
also that sufficient side light illumined his features, he
could have seen quite well enough to shave himself, or
by holding a piece of printed paper downwards, not
quite squarely but a little slanting, so as to catch the
light, he could have had little difficulty in reading
any ordinary type. Circumstances would have still
further helped this experiment if a projecting roof or
tree had overhung, so as to somewhat moderate the
overwhelming light background of sky. From this it
will be seen that experimenting with a white shallow
basin near a window was a ridiculously unfair test of
the truth of the old story, whereas were he to have
stood over a deep dark overshadowed pool, which
might reasonably have been presupposed, he would
have found that the gross blunder was hardly in the
fable.

But the controversy alluded to elicited some well-
established physical facts which supply the argument
of the present paper. It was first of all pointed out
that the image of the banks of a lake or river viewed by
an observer stationed at a considerable distance on the
onfiosite side are very vivid, but become less so if the
observer, being, we must suppose, in a boat, begins
to approach nearer, the reason being that " when a
ray falls so obliquely upon the surface of water as to
make with the surface an angle of 15°, nearly a fourth
of all the incident rays are reflected."

All this, however, can be stated more simply and
intelligibly. -Ml the world knows the difficulty of
hitting any object under water with a shot gun. If
fired nearly perpendicularly downwards over the side
of a boat it is true that the shot will penetrate the
water fairly steadily and truly, but it is otherwise if
the gun has to be pointed in a slanting direction. In
this case the shots enter the water reluctantly, taking
only a shallow dive below, and in an extreme position
the shots will not enter the water at all, but be re-
flected sheer off the surface.

It is practically the same with rays of light, and so
it comes about that the image of a distant bank, being
seen by rays which are very much aslant, and, there-
fore, very well reflected, is particularly vivid. And

the converse of this is also true, thus — Imagine a suffi-
ciently distinguishable object, say a fish's eye, three
feet below clear water. This might be seen readily
from a position directly overhead, but less distinctly
if viewed at a slant angle, and actual experiment shows
that all rays from the fish's eye which are so aslant
as to reach the surface of the water beyond a radius
of four feet never get out of the water at all, but are
simply reflected back from the water's surface, which
in this case acts as a perfect mirror. Thus an ob-
server looking towards the fish from a position which
is outside this limit will not see the fish, nor — pace
certain fishermen I have known — will the fish see him.
To put this fact beyond dispute let the following ex-
periment be tried. Stand a tumbler nearly full of
water on an open newspaper near the edge of a table,
and then, placing your eye on a level with the table and
six inches from the tumbler, look aslant upwards at
the surface of the water. You then learn in a most
convincing manner that the water's surface allows no
outside rays to pass to your eye, but simply behaves
as a mirror, revealing the print of the paper \\ith the
most perfect reflection.

We are now prepared to begin an enquiry into a
curious and all-important phenomenon which it fell to
the lot of the writer to be able to put to a crucial test.
It needs no pointing out th.nt in na\al warfare, as being
carried on at the present hour, there is nothing more
deadly or more to be dreaded than the snares which
are caused to lurk beneath the water — the mine, the
torpedo, and the submarine. It is of paramount im-
portance, therefore, to get, if by any means, some
inkling of all that may lie at a moderate distance be-
neath the water line, and it has long been known that
this may best be done by looking down into the water
from a considerable height overhead. Even in peaceful
navigation, when some danger, as, for instance, a shoal
or sunken wreck or the like, is suspected of lying in
a vessel's course, but cannot be seen from deck, then
it is customary to send a man aloft, and the higher in
reason that he can climb the further will his vision
penetrate, and the better will his eye command a view
of any submerged object. It was to determine the
full extent to which this fact could be turned to ac-
count that the writer was commissioned under the
auspices of the Admiralty to endeavour to obtain photo-
graphs of the sea bottom from a balloon. This feat
was actually accomplished during an aerial sail over
the Irish Sea from the Isle of Man, a voyage which
became historical, and which resulted in the securing
of a very remarkable photogr.iph of the sea
bed, showing varied rock and sand lying in 10
fathoms, that is 60 feet of water, and that water
strongly ruffled after a week of boisterous weather.

Now it should be clear that the half of the secret of
success in such an attempt has been already told.
For if, say, a sunken vessel were lying in a few fathoms
of water, and a man were looking down on it from a
boat, and floating somewhere just over its middle part,
then that middle part might be fairly well seen, but
the more distant parts bfith fore and aft, being viewed
at a slant angle, would probably be altogetbiT invisible.
If, however, the observer were to be let up a quarter
of a mile into the sky, and to look down from there,
all parts of the vessel would now lie practically per-
pendicularly below, .'md all would be equally well seen.

But in attempting to look beneath the water's surface
at sea there is another obstacle to be reckoned with,
and that is the usually troubled nature of that surface.
For it is an everyday experience that objects which may

May, 1905 ]

KNOWLEDGE & SCIENTIFIC NEWS.

be distinct enough below still water become indistinct
or invisible if the water be disturbed. To obviate this
difficulty it has become customary to make use of a
very efficacious and useful instrument called a water
telescope, which need be nothing more than a large
tube, say a foot in diameter, and say six feet long,
closed at one end with a sheet of glass. This end is now
plunged beneath the troubled surface of broken water,
and the observer applying his eye at the open end is
at once able to see as clearly as if the water were un-
ruffli-d, as, indeed, to his eve it now is.

But let us pass on to consider how it is that the
surface of a transparent medium when broken up re-
fuses to allow rays of light to have free passage. Let
us take the case of a piece of clear glass, lying on a
newspaper, the printed matter of which is then seen
with perfect distinctness. But now commence pound-
ing up the glass with a hammer and you find that the
more completely the glass is broken up the more is
the printed page obscured, and when at last the glass
has become mere fine powder, it appears as a white
mass like so much salt, and nothing is seen behind it.
The fact is that light cannot penetrate the mass, be-
cause each ray as it passes from fragment to fragment
glances hither and thither off a myriad minute sur-
faces, and thus wastes itself in a multitude of reflec-
tions. In scientific parlance the optical continuity is
broken and the mass of powdered glass looks white
simply because it only reflects back the white light of

day. It would have appeared just as white had the
glass been coloured, or even black. In the same way
and for the same reason the frolh on a glass of
Guinness's stout, instead of being dark brown, appears
white or nearly so.

We now grasp how it is that without a water tele-
scope it is difficult to see through the surface of
troubled water at close quarters, but the fact which
we illustrate yet remains, namely, that when the eye
is removed to a distance the distraction caused by the
broken light largely disappears, and objects below are
seen more clearly. Another example strictly analogous
of the same sort of thing is afforded by either cloud or
mist. Cloud is simply composed of particles of water
mingled with particles of air, and though both
separately are perfsctly transparent, confused together

they form a mass which stops and reflects back the
light, and for the same reason the illumined surfaces
of clouds are white, but in actual fact the stoppage of
light is not so complete as it appears, and a thin veil
of mist will behave precisely as the broken water's
edge, obliterating the view at short range, but to a
more distant observer allowing objects to be seen
through it with tolerable distinctness. Thus it often
happens that a balloonist whose view of the outside
world is wholly obscured by a shroud of thin mist can
be quite clearly seen by those at a distance.

It should then be only in accordance with theory
and known fact if the secrets of the sea depths, which
hide themselves even from the trained eye of the sailor
on board ship, should become revealed to an aeronaut
who will poise himself in space overhead, say 10 times
higher than the maintop.

It scarcely needs the further pointing out that there

KNOWLEDGE & SCIENTIFIC NEWS.

[May, 1905.

is always some of the light which, striking water, is
neither Ecflected nor refracted, but simply scattered.
It may sound strange, though it is perfectly true, that
were it not for this scattering of light the surface of
water would never be seen at all, even in broad day.
It is just in the same way that the surface of a polished
mirror cannot be seen except where there may be some
scratch or smear upon it, and so true is this that in
unfamiliar houses we sometimes surprise ourselves by
walking up against walls which bear whole length
mirrors in unexpected places. In the photograph of
the sea bottom it will be noticed that the broken sur-
face of the sea is seen all over the picture, notwith-
standing the fact that through it all and below it all the
sea floor is seen also.

Once below the surface, however, the ray travels
far more readily than is generallv sunnosed. The
swimmer who, in diving, is accustomed to open his
eyes under water is apt to imagine that very distinct
vision is out of the question, but he forgets that the
cause of this is due to the disturbance which his own
motion is causing in the water. A fish, on the other
hand, remaining motionless below, with an eye adapted
to its surroundings, may see remarkably well. And
on occasions it is brought home to the ordinary ob-
server how well light may pass into clear water, and
down to the depths below, and emerge again still in
strength enough to ensure good vision. This beautiful
phenomenon is particularly noticeable at the far end
of some of the Norwegian Fjords, where the sea water
has almost parted with its salt, and where no ap-
parent tides disturb the pure and peaceful depths.

It is on looking down into these depths that one
curious and not unimportant fact has to be thought of,
namely, that they are much deeper than they seem to
be. This follows of necessity from what has been
already said, namely, that a ray whose path lies partly
in air and partly in water takes but a shallow cour.se
through the water, a truth which is made perfectly
apparent by simply dipping a stick or finger into a
basin of water.

An amusing example of this illusion was forcibly
impressed upon a friend of the writer, who went to
take a morning dip in the swimming bath of an hotel.
The hour being early, no one was about, and being
long unfamiliar with baths of that description, he took
his plunge at an end where the depth appeared per-
fectly shallow. To his surprise, however, he found
himself the next moment in seven feet of water, and
then, and not till then, the teaching of his Cambridge
days came back to him, and he reproached himself that
he had not known better. For the rest it mattered
not, for in those olden days Cambridge had not known
a .stouter swimmer, and, happily, ' that one art .so
foreign to man, when once learnt, never deserts him
more.

Ra.diatiorv from Hydrogen
Peroxide.

Much interest has been caused in Germany by the
statement that it was found that photographic plates
were affected by hydrogen peroxide, even though
-screened by thin sheets of metal. It has been sug-
gested, on the other hand, that the hydrogen peroxide
IS capable of penetrating such screens through minute
and inperceptible holes.

TKe Intern aLtiorvQLl

CoLtaLlogue of Scientific

LiteroLtvire.

"The International Catalogue of Scientific Litera-
ture," published for the International Council, by the
Royal Society, London — Harrison and Sons. 17 vols.
Svo. Price, ^18.

It is probably known to most of our readers that one of
the greatest difficulties encountered in these days by
workers in all branches of science is to ascertain what
their fellow-w-orkers have lately done and are now doing.
This difficulty is greatly increased by the enormous
number of scientific periodicals published all over the
world. Besides the numerous journals devoted to special
subjects, every museum and other scientific institution
issues its own "Proceedings" or " Transactions," which
often contain scientific information of the most varied
character. Taking Zoology, for example, we find in the
last volume of the " Zoological Record " a list of the titles
upwards of a thousand periodicals devoted to that
science alone, and in other branches of science there is
probably a corresponding number of publications of this
sort, which have to be carefully studied, in order to find
out who is working, and what has been written on any
particular subject. It is obvious, therefore, that even a
catalogue of the titles of published books and papers
would be a very great assistance to workers in science.

The idea of forming such a catalogue of scientific books
and papers seems to have been first entertained in modern
days by the late Dr. Joseph Henry, Secretary of the
Smithsonian Institution at Washington. Dr. Henry
sent a communication to the meeting of the British
Association at Glasgow in 1855, suggesting the formation
of a catalogue of Philosophical Memoirs, which was
favourably reported upon by a committee appointed to
consider it. Two years later, in 1857, the late General
Sabine brought the subject before the Royal Society,
and requested the co-operation of that Society with the
British Association on this matter, .\fter some negotia
tions the Royal Society ultimately took up the undertaking
seriously and published the first volume of their catalogue
of scientific papers in 1867. This was subsequently con-
tinued until there are now twelve large (juarterly volumes
which contain the titles, alphabetically arranged accord-
ing to the authors' names, of all the scientific papers
published from 1800 to 1885. On referring to the last
report of the Council of the Royal Society we find it
announced that the great work of completing this cata-
logue to the end of k^oo is now making rapid progress,
but that the vast bulk of the material to he dealt with
has much delayed its issue. When it is finished it will
make the " Catalogue of Scientific Papers" complete
up to the end of the last century.

The question of the best mode of ensuring the con-
tinuance of the catalogue during the present century,
having been maturely considered by the Council of the
Royal Society, it was determined that this arduous task
could best be carried out by the mutual co-operation of
all the nations interested in the progress of modern
science, and an International Conference w'as conse-
quently summoned by the Royal Society to consider the
question. This Conference took place in London in
July, 1896, and was attended by delegates from twenty-
one countries. It was unanimously agreed by all the
delegates that an " International Catalogue of Scientific

May, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

loi

Literature " should be undertaken, and that it should
commence on January i, 1901, where the " Catalogue of
Scientific Papers " would come to a conclusion. It was
also agreed that the International Catalogue should be
controlled by a "Central Bureau" established in London,
while the other countries should each have a " Regional
Bureau " to collect the necessary information on the spot
and transmit it to the Central Bureau. At two other Con-
ferences, held by the Royal Society in London in 1898 and

1900, the scheme was further elaborated, and numerous
details were settled. It was agreed that the Catalogue
should be published in London in seventeen annual
volumes, each of which would relate to a separate branch
of science and be distinguished by the letters from A to R.
The general plan of the catalogue is given in the sub-
joined extract from the prospectus of it.

The " International Catalogue of Scientific Literature "
contains an Authors' and a classified Subject-Index of
the Scientific Literature published on and after January i,

1 90 1. Each country has undertaken to mdex its own
literature. The material thus collected is sent to the
Central Bureau in London, where it is arranged accord-
ing to ((() Authors' Names and (b) Subject-matter, and
published in annual volumes. A Schedule of Classifica-
tion and an Index thereto are prefixed to each volume in
English, French, German, and Italian. These, and Latin,
are the only languages which are used in the Catalogue
without a translation, but in the Authors' Catalogue the
titles of all publications are given in the original language.
Each volume contains the material received at the Central
Bureau since the date of completion of the manuscript of
the previous volume.

The following is a list of the seventeen volumes (A to
R) of the First Annual Issue (1903-4) of the International
Catalogue, and of the prices at which they are sold sepa-
rately ; the price of the whole set being ^18 : —

Mathematics ....
Mechanics ....
Physics (Part I.) . .

(Part II.) . .

Chemistry (Part I.) . .

(Part II.) .

Astronomy

Meteorology ....

Mineralogy

Geology

Geography

PaliEontology ....
General Biologs . . .
Botany (Part I.') . . .

(Part II.) . .

Zoology

Human Anatomy . .
Physical Anthropology
Physiology (Part I.) .
(Part II.) .
Bacteriology ....

Ordinary

Thin Paper

Volumes.

Price.

15/-

16/6

10/6

12/-

21/-

22/6

15/-

16/6

21/-

22/6

18/-

19/6

21/-

22/6

15/-

16/6

15/-

16/6

15/-

16/6

15/-

16/6

10/6

12/-

10/6

12/-

21/-.

22/6

18/-

19/6

37/6

39-

10/6

12/-

10/6

12/-

21/-

22/6

IS/-

19/6

21/-

22/6

The second and third Annual Issues are now in pro-
gress of publication.

All scientific men will, we think, approve of the general
plan of the "International Catalogue of Scientific Lite-
rature," and be very grateful to the Royal Society for
the institution of a piece of work which cannot fail to be
of material assistance in scientific research. But we will
now proceed to consider shortly the way in which the
initial volumes of the new catalogue have been prepared,
and whether they contain the information required by
the students of the branches of science to which they

respectively relate. To this inquiry, however, we fear
it is not possible to give a quite satisfactory reply.
While some of the volumes of the first Annual Issue,
to which we will confine our remarks, receive unstinted
praise, others, it is only right to say, have met with a
great deal of severe criticism. In the latter category we
may specially point out the volumes on Palasontology
and Zoology, both of which are generally considered not
to be "up to the mark," as the phrase is. It is, of
course, unreasonable to suppose that in commencing the
difficult task of inaugurating such a gigantic undertaking
as the present mistakes will not be made. We may also
be quite sure that Dr. J. Foster Morley, the director of
the whole undertaking, and his assistants in the prepara-
tion of the long series of volumes have done all in their
power to avoid errors. But in some cases they ha\e
certainly not altogether succeeded in doing this. It has
been shown on competent authority that the list of publi-
cations for the year 1901, which is, of course, the most
important part of every volume, is by no means com-
plete in the two volumes specified and in several others,
and that the subject-indexes are consequently also defec-
tive.- In the subject-indexes cases of misplaced titles are
also by no means rare. These points, we hope, will be
more carefully attended to in future volumes. But we
venture to recommend that the so- called " Referee " of
each volume should be given larger powers for additions
and alterations than, as we understand, have hitherto
been accorded to him. The Referee should be well paid
for his labour, and should be deemed to be absolutely re-
sponsible for the correctness of his volume. It is, of
course, absurd to suppose that the general editor of the
work could be perfectly acquainted with all the sciences
to which the seventeen volumes relate, and the respon-
sibility should be attributed to the so-called Referees.

Having said thus much, we will add a few words
upon some of the general features of the International
Catalogue. In the first place, we object strongly to
the shabby paper-covers in which the volumes are
issued. They are quite useless for protection, and
necessitate the immediate binding of the volumes, in
boards at least. To deliver bulky volumes of this kind
in thin paper covers seems to us to be a very unbusiness-
like proceeding, and likely to hinder their sale. On
the other hand, the paper and print of the volumes
are decidedly good, though the margin left on each side
is, in our opinion, decidedly insufficient. As regards the
prices at which the volumes are sold, they are in many
cases decidedly exorbitant. Scientific men, we are sorry
to say, are seldom possessed of large means. To charge
an unfortunate zoologist thirty-seven shillings and sixpence
as the cost of his volume is, in fact, a prohibition to
buying it, and will seriously interfere with the sale of the
work. A third point to which we must call attention is
the great delay that has taken place in the publication of
the volumes. Those relating to 1901 should certainly
have all been issued before the close of 1902. Scientific
men, like other persons in these days, are always
expected to be well " up to date," and cannot be required
to wait three or four years for the information they
require. Here, again, it may be answered thatanewand
gigantic undertaking like the present must be allowed a
little time to acquire its full organization, and that we
should not be too hard on the delay. To this we reply
that delay is dangerous in this sort of work. It is often
very difficult, if not impossible, to make up arrears, and
unless strong means are taken at once to bring the "In-
ternational Catalogue of Scientific Literature" com-
pletely up to date, it will lose, we fear, a great part of its
undoubted value to workers in science.

lOi

KNOWLEDGE & SCIENTIFIC NEWS.

[May, 1905.

The OpticaLl Convention.

The programme of arrangements for the Convention is
now beginning to assume a definite shape, and particulars
as to what is at present proposed will no doubt be of interest.
The Convention will be formally opened with an
address from the President, Dr. R. T. Glazebrook,
M..\., F.R.S., Director of the National Physical Labora-
tory, on the evening of Tuesday, May the 30th, and the
gathering will extend over the four following days, up to
and including Saturday, June the 3rd. The mornings
will be devoted to papers and discussions, and in view of
the interesting series of papers already announced, there
is no doubt that this most important section of the pro-
ceedings will result in valuable contributions to Optical
science, and will fulfil the aims which those who have
been active in promoting the Convention have set before
them. In addition to the papers, demonstrations of
apparatus of special mterest will be given in the after-
noons in the Laboratories of the Department of Technical
Optics of the Northampton Institute.

The Exhibition of optical and scientific instruments
will be held in the large Hall of the Northampton
Institute, and will be open daily to the public from 12 to
10 p.m., between May 31st and June 3rd inclusive. The
charge for admission will be one shilling during the day,
and si.xpence after 7 p.m.

The Catalogue is now in active preparation. The
arrangement made by the " Exhibition and Catalogue"
sub Committee that each section should be dealt with by
an expert in the construction of the instruments repre-
sented in the section, together with an independent
scientific member of the Committee, will ensure that all
classes of instruments shall be adequately dealt with and
described. It is proposed to fix the sale price of the
Catalogue, which will be a volume of some 300 quarto
pages, at is. 6d. ; while in large numbers of 100 and
upwards, the Catalogues will be issued to firms at a cost
of IS. each. The Hon. Secretary would be glad to hear
at once from firms wishing to take a number of the Cata-
logues for private distribution.

Arrangements for promoting the social interest of the
gathering, and for providing for the comfort and conveni-
ence of members attending from outside London, are now
being considered by a " Hospitality and Entertainments "
sub-Committee. In addition to the Presidential address,
to be given on the Tuesday evening, which has already
been mentioned, there will be an evening lecture by Pro-
fessor Silvanus P. Thompson, D.Sc, F.K.S., on " The
Polarization of Light by Nicol Prisms and their Modern
Varieties." On a third evening it is proposed to hold a
Conversazione; and for the Saturday afternoon, a visit
to the National Physical Laboratory at Teddington is
proposed, at the kind invitation of Dr. Glazebrook, the
President of the Convention.

Further particulars will be announced later, when the
programme is more definitely settled. It will greatly
help towards ensuring the social success of the Coven-
tion if intending members will send in their applications
at once ; the subscription for membership is 5s. The
Hon. Secretary, Mr. F. J. Selby, Elm Lodge, Tedding-
ton, Middlesex, will be glad to hear from those wishing
to join the Convention.

The " Local Societies and Representatives " sub-
Committee is dealing with the question of facilities for
the attendance of visitors from a distance. The Secre-
tary of this Committee is Mr. W. Rosenhain, B.A., 443,
Gillott Road, Edgbaston, Birmingham. Mr. Rosenhain
will be glad to give information in answer to enquiries,
and will also be ready to receive applications for mem-
bership of the Convention.

A Curiovis Induction
Experiment.

By Ch.^klks E. BtNii.\.\i.

The following curious experiment, simple as it is, will
probably be new to most readers. Place on a level table
two glass tumblers which have been first freed from any
superficial moisture by warming them near a fire. Lay
a book on each tumbler, the two books being of similar
size. The longer sides of the books should be parallel
with each other, and the supporting tumblers should he at
such a distance apart that the two books are about one
inch apart. Place a third book of the same size on a
sheet of glass, which must also have been well warmed
at the fire. The third book must be laid so that it rests
crosswisT over the other two. with the sheet of glass

•

FiK. I. A and li the two lower hook.%. C the upper book, reslinK ntl
the Klas» plate D, and carrying a small coin, laid on the top of
the book.

between them, as shown in fig. i, in which the dotted
line represents the piece of glass, the proportionate size
of which is thus indicated. On the top book lay a penny,
as indicated in the diagram, to act as a conductor for
drawing ofl' the electric sparks which are to be produced
by this singular arrangement. Now taking the glass
carrier, and holding it near tiie front edge, mme it, with
its book, horizontally right and left, so that the upper

c ■■

(. 1. A and II the two lower hof.kt. C t
pnrtlne kIo>* plate not nluiwn> In It* exi
»ame book In its extreme riKl'l roHilion.

lelt position. C the

May, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

103

book is in turn over each of the lower ones, in the alter-
nate positions shown in fig. 2. Whenever it reaches
either of these extreme positions, touch the book under-
neath it with the finger, taking care not to touch the
other book, nor the upper one. When the upper book is
in the intermediate position shown in fig. i it must be
touched, taking care to avoid the earthing of either of the
others. Repeat this cycle of movements twelve or twenty
times, and then, on lifting the glass plate with its book
away from the influence of the other two, a little spark may
be drawn from the penny on presenting a finger to it. After
drawing the spark replace the plate in the intermediate
position (fig. i),and on earthing the upper book again by
touching it as before, its charge will be restored. Con-
tinuing the movements, it will be observed that the charge
is a growing one, increasing at each cycle, being only
limited by leakage from the book corners and by the capa-
city of the book surfaces. The charge on the upper book
may be given up to a Leyden jar each time without loss
if the communication from it to the jar is always made
previous to its intermediate position, in which, when it is
earthed, its loss is made good by induction from the books
below. Using large books on the tumblers and, for the
upper one, a book of equally extensive surface, though thin
for the sake of lightness, quite a strong charge may soon
be accumulated in the Leyden jar. If the tumblers and
glass sheets are coated with shellac varnish they are less
liable to be affected by moisture, and the preliminary
warming is unnecessary unless the atmosphere is very
damp. The effect is enhanced by using rounded pieces
of board instead of the books, and the best effects of all
are produced if the conductors are of metal. Three
shallow cake tins, about eight inches in diameter, will
give very fine sparks, and the snap of the induced charge
quickly becomes audible at each successive earthing, the
spark of inflowing electricity becoming larger each time
until the limit of capacity is reached. The glass will
indeed soon become so highly charged that in moving it
the cake tin will adhere to it by attraction, while if the
lower tins are close together a spark will also frequently
ffy between them as the upper tin passes from one side
to the other. When this happens, however, the process
of accumulation is to some extent checked, and the proper
distance apart is the shortest distance at which such
cross-sparking does not occur.

The experiment is really a modification of one which has
already been described and explained in " Knowledge "
(November, 1904). Each of the lower books receives an
infinitesimal charge by induction from the upper one,
which, without losing any of its own, is in its central
position enabled, when temporarily earthed by touching,
to take up an induced charge from the joint influence of
both the under ones. Its original charge is thus multi-
plied at each cycle. Where that original charge comes
from is, of course, a mystery. It is infinitesimal, but it is
there somehow, and may be either positive or negative —
sometimes one, sometimes the other. It appears that all
insulated bodies are at a slightly different potential from
earthed bodies, and though it may be difficult to say
exactly why they should be, the fact that they are is
sufficient to account for the apparent miracle of self-
excitement which characterises nearly all induction
machines.

Perhaps one of the most interesting suggestions arising
from the experiment suggested above is in connection
with the phenomena of atmospheric electricity. The
effect of the movements of the books is so obviously sug-
gestive of the influence which cloud masses must exert
upon each other when one passes over two, with an
intervening space to separate them, that there is no resist-

ing the conclusion that in the phenomena of the thunder-
storm we frequently witness on a large scale an almost
precisely similar experiment of Nature to that which we
have been performing on the dining-room table with the
three books to represent the cloud masses. Especially
suggestive is the flashing of the sparks from one of the
lower plates to the other, which occurs, as already men-
tioned, when they are placed very close together every
time the upper plate passes across them. Here undoubt-
edly we have the very counterpart of the phenomenon
often observed in a thunderstorm, when, drawn by the
influence of some upper layer of moving cloud, the light-
ning flash darts across from one charged cloud mass to
another in a lower stratum.

Star MoLps.

With this number we present the first of a series of Star
maps, which we hope will be found useful to our readers.
These charts of the heavens embody some new ideas of
design which, while causing the stars to be clearly
depicted as they appear in Nature, yet enable the
student at once to identify the individual stars and con-
stellations.

One of the most difficult points to decide upon has
been the method of projection. It is, of course, im-
possible to represent all the objects on a spherical sur-
face, such as that which the heavens appear to be to our
eyes, in their exact relati\e positions on a flat piece of
paper. If, however, that piece of paper be cut up into a
number of small independent planes, each can more
accurately represent one portion of the sphere. So if
the surface of a globe were cut up into a hundred equal
parts, each of them would be practically flat, or if abso-
solutely flattened the position of the stars marked thereon
would not be greatly distorted. But such a series of very
small maps would be of comparatively little practical use.
The principal constellations would be split up into many
parts, and their general appearance lost. It is desirable
to form the maps in sheets as large as possible, both for
convenience of reference and for noting the relative
positions of stars and groups of stars. If we find one
object on a map we may wish to see in which direction
the various neighbouring stars lie, but this would be
almost impossible on very small maps. So for practical
work we require the maps to be as comprehensive as
possible. But any division of the globe into parts has,
to some extent, the objection that constellations and other
groupings are often divided. This may be overcome by
so arranging the maps that they overlap somewhat, and
the stars appearing near the borders of one may be
repeated on an adjacent map.

Taking all these points into consideration, we believe
that no method can be better than that adopted by
Proctor in his " Star Atlas " (published in 18701, and it
seems appropriate that we should adopt the system
first introduced by the founder of "Knowledge."
We can but repeat the words of his Introduction.
"It is clear that, cceteris paribus, that plan is best
which represents the celestial sphere in the smallest
number of maps. Further the maps should be con-
venient in size but yet on a sufficiently large scale ; and

I04

KNOWLEDGE & SCIENTIFIC NEWS.

[May, 1905.

of two plans, otherwise equal, that one will be best which,
on a given scale, and with a given number of maps,
makes the maps cover the least possible area. It is also
obvious that the distortion and scale variation of a map
should be as small as possible." He also says " There
is only one plan according to which such an atlas can be
constructed so as to satisfy even the chief requisites
which Star Charts are intended to meet." If the maps
are to be of equal size and shape, the surface of the
sphere must be approximated by a solid figure com-
posed of a number of faces each forming a polygon.
But of these the most suitable is the dodecahedron, or
solid figure composed of twelve pentagons. From the
figure it will be evident how each one of the pentagons,

though forming a flat plane, will not require that the
position of the objects depicted upon them will be much
distorted from those on the surface of a sphere. It will
be noticed that the distortion is greatest in the angles of
the pentagons, so if a circle be circumscribed around the
pentagon, the distortion of those part* outside the penta-
gon will be no greater than those in the angles, and the
circle will practically occupy no greater space of paper
than the pentagon. By adopting the circle instead of the
pentagon we also obtain another important feature, and
that is the overlapping of the adjacent maps. In these
12 maps one-fifth of the hea\ens is included in the over-
laps. Occasionally stars lying near, but outside, the
border are shown, so as to complete the principal mem-
bers of a constellation.

Having decided upon this system, the ne.xt question
was as to the colouring and mode of representing the
stars. Most maps mark the stars in black on a lighter
ground, the opposite to Nature, and causing much con-
fusion with letters and signs. White stars on a blue
ground have therefore been adopted.

The names of the constellations are here put in large
letters, so arranged as to cover as far as possible the con-
stellation, and yet being so placed as not to interfere with
the individual stars. The lines of R.A. are only given for
the hours, though around the border divisions are put
corresponding to each ten minutes, and Declination lines
are put at each 5 degrees.

As regards the nomenclature of the stars, we have
added names to all those mentioned in the Comte de
Miremont's Popular Star Maps, the Greek letters to those
recognised by such, and I-'lamsteed's numbers to others.
There remain many other smaller stars, which bear various
numbers according to different catalogues, but we have
thought it best to leave them unnamed, as otherwise con
fusion may be caused.

The brilliancy of the stars, known by the misleading
designation of " magnitudes," but which, of course, has
nothing to do with the actual size of the stars, are here
given according to conventional shapes (as shown on each
sheet). The actual si/.e represented varies slightly, since
the stars are not, as a rule, of any txaci magnitude. These
are entered in accordance with the Harvaid I'hotometry.

The Milky Way has been added in a manner which

may not perhaps appear wholly satisfactory, but it be-
comes a practical difficulty to depict that which is but a
mass of stars in such a way as to interfere as little as
possible with stars superposed upon it. Many other
practical difficulties have appeared during the construc-
tion and printing of the first map, but in future we pro-
pose to employ a slightly different system, which should
secure greater clearness and accuracy.

MAP I.

North Polar Stars.

This is perhaps the most important map of the whole
series for several reasons. All the stars here represented
are always above the horizon in England. One of the
chief practical uses in a knowledge of the position of the
stars is to be able to ascertain the direction of true north.
l>y becoming conversant with the lie of the chief stars
in tliis region the north point is readily noted. Besides
these this map happens to include several of the most
conspicuous and easily remembered constellations in the
heavens, viz., the Great Bear, the Little Bear, and
Cassiopeia.

It may be almost superfluous to mention that the North
Pole of the heavens is found by prolonging the line of the
" pointers " (jt and 0. Ursa Majoris) towards Polaris, which
star stands very much alone, and close to the Pole. If
Polaris be joined by an imaginary line to the end of the
"tail" of the Great Bear (-n) the Pole will be approxi-
mately where these two lines cross.

Among the more noteworthy stars and other interest-
ing objects to be found in this map are the following : —

0 Cephei {2 ih. 2^m. + 5/' 54')- Double. The princi-
pal star is variable from 3-7 to 4-9 magnitude, and is a
spectroscopic binary of great interest. The variability,
in this case, is proved not to be dependent on eclipse
obscuration with a darker body, but seems to be due to
an actual variation in radiating power.

o Cassiopeia (oh. 34m. + 53' 59') is a quadrupal and
irregular variable ranging from 2-2 to 2'8 mag.

V Cassiopeia (oh. 43m. -|- 57" 17'). A binary, the two
stars being of 3-5 and 7-5 magnitudes respectively, at a
distance apart of 5"-b8.

a Cassiopeia (23h. 54m. + 55° 12'). A double star, one
white, of the 5th magnitude, the other blue of 7-5 magni-
tude. Distance apart 3"-o.

Perseus, between 9 and 5 are two clusters. Near this
point a Nova was discovered in 1895, of the 9th magni-
tude.

a Ursa Minoris, "Polaris" (ih. 23m. -f 88" 46').
Mag. 2-12. This is a double star, the smaller one at a
distance of 19" being of 9th magnitude. The larger star
is a spectroscopic binary, period 4 days, probably having
two dark companion stars.

In Ursa Major close to ji is situated the " Owl Nebula "
(iih. gm. + 55' 34') invisible to the naked eye, but by
aid of powerful telescopes is seen to consist of two spirals
formed in opposite directions.

(Ursa Majiiris, "Mizar" (i3h. 20m. + 55" 26'). A
well-known double star, magnitude 2-i and 4-2, distance
apart J4"'4- Position angle i47""4. The larger star is a
spectroscopic binary of two bright and equal components.
"Alcor," 5th magnitude, is ii" away from (.

Draco. A gaseous nebula, of a pale blue colour, lies
close to the north pole of the ecliptic. (i7h. 59m. +
66'^ 38').

From a point in Perseus dh. om. -f 57'"') come the
well-known Perseids, or meteor showers, about the 9th-
iith of August.

PPLEMEKT TO "KXOWI.EDUE & SCIENTIFIC NEWS, " Mail, 1005.

MAP No. 1.

A P 2

£■/

:st

■■T

■v"l

. 1

MAP No. 1.
Northern Polar Stars.

May, 1905.

KNOWLEDGE & SCIENTIFIC NEWS.

105

MoLmmals that Carry
Their Young.

By R. LVDEKKER.

" While taking bats one day in December, I captured
a female of our common Buenos Ayrean species
(Molnssus bonariensis), with her two young attached to
her, so large that it seemed incredible she should be
able to fly and take insects with such a weight to drag
her down. The young were about a third less in size
than the mother, so that she had to carry a weight
greatly exceeding that of her own body. They were
fastened to her breast and belly, one on each side, as
when first born; and possibly the young bat does not
change its position, or move, like the young developed
opossum, to other parts of the body, until mature
enough to begin an independent life. On forcibly
separating them from their parent, I found that they
were not yet able to fly, but when set free fluttered
feebly to the ground. This bat certainly appeared
more burdened with its young than any animal I had
ever observed. "

Thus wrote Mr. W. H. Hudson in that delightful
book, " The Naturalist in La Plata," rather more than
a dozen years ago. The passage appears, . however,
to have been generally overlooked by later naturalists
(the present writer among the number), for in 1902 the
fact that certain female North American bats habitu-
ally carry about with them more than a single offspring
clinging to their own bodies was brought to notice as
an entirely new discovery. So utterly incredible, in-
deed, did it appear to naturalists of an earlier date,
that a bat should be able to fly with a couple of young
ones clinging to her breast, that in 1878 the late Dr.
G. E. Dobson expressed the opinion that, in the case of
twins, one of the pair might be transferred to the male
parent, and carried about by him. Not only, how-
ever, has no instance of such a transference ever been
observed, but the discovery that female bats are cap-
able of carrying not only two but actually four offspring
about with them indicates that, in the great majority
of species, it never occurs at all.

The case of the above-mentioned North American
bat (Lasiurus borealis), of which a full description wull
be found in " Knowledge " of November, 1903, alto-
gether eclipses the instance quoted by Mr. Hudson, for
two specimens of this species have been brought to
notice with four young ones clinging to their nipples.
And although no one has hitherto taken a female thus
loaded in actual flight, from the fact that bats of the
genera Lasiurus and Dasyptcrus are furnished with two
pairs of nipples, it appears probable that a quartette of
young ones is commonly carried by the female parent
during her aerial wanderings. On the other hand, as
European bats have but a single pair of nipples, it may
be inferred that the females never carry more than two
young, although an instance of even this does not ever
appear to have been observed.

As already mentioned, the weight of the twins
actually seen to have been carried by the South Ameri-
can species is reported to have greatly exceeded that
of her own body. In the case of one of the North
American specimens, the weight of the quartette was
12.7 grammes; while that of the mother was only 11
grammes. The offspring in this instance were, how-
ever, much younger than in the case recorded by Mr.
Hudson, so that it is a fair inference in the instance of

the North American species that the weight of the off-
spring would have eventually doubled that of the
parent before the burden was finally discarded. How
such a sorely over-burdened mother could have
managed to fly at all is little short of a miracle.

From their peculiar mode of life it is, of course,
evident that bats of all kinds must habitually carry
their young about with them; and in the case of the
large fruit-bats, or flying-foxes, which can be easily
kept in captivity, it has been observed that in repose
the young cling head-downwards to the under surface
of the body of the female parent (Fig. i). In the re-
markable naked bat (Chirnmchs torquata), of the Malay
countries, the absence of fur would, however, effectually
prevent the young being carried about in the ordinary
way; and we accordingly find the nipples enclosed in
large pouches of skin, which doubtless form receptacles
for the young bats. From the fact that these pouches
are present in both sexes, it has been suggested that,
in the case of twins, the care of one of the pair is
undertaken by the male parent. Even, however, if
twins are ever produced by this species, the case of
the above-mentioned American bats suggests that no
such transference of a share of the burden is essential.

Fijf. 1. -Female Fox=Bat with young

1__^^ ..J

, (From Sclaler, Pruc. Zvol. Soc.

Next to these sorely-tried American bats, the most
overburdened animals would appear to be the females
of the American opossums, some of which are in the
habit of carrying their numerous progeny about with
them on their backs, as many of the young as can find
room securing a firm hold by twisting the tips of their
own prehensile tails around the tail of their parent,
which, in some instances, at any rate, appears to be
bent forward over her back for this special purpose. _ In
the case of one of the larger South American species,
which is considerably inferior in size to an average
cat, Mr. Hudson tells us that he has seen as many as
eleven young ones, each as large as a full-sized rat,
carried about on the parental back. In this instance
the burden must be proportionately greater than in the
case of a terrestrial animal, for these opossums when
thus loaded follow their usual practice of climbing
swiftly and with the greatest agility among the higher
branches of trees. Indeed, it would seem that the
creature must capture its prey while thus burdened
for the members of the family, like Sinbad's old man of
the sea, seem never to voluntarily relinquish their
equestrian position until old enough to shift for them-
selves.

io6

KNOWLEDGE & SCIENTIFIC NEWS.

[May, 1905.

To make the parental back serve the purptose of a
perambulator seems, indeed, to be fashionable among
South American animals, for Mr. Hudson tells us that
the females of the large aquatic rodent of that country
locally known as the coypu or nutria (Myopolamiis
coypu) are in the habit of carrying at least some por-
tion of their family \\hile swimming. Not that the
little coypus, which usually number eight or nine,
cannot swim perfectly well by themselves, but
they are probably unable to keep up the pace for any
distance, and it is quite common to see as many as can
find room comfortably seated on their mother's back,
and the rest swimming behind on the look-out for their
turn for a ride. Whether beavers and water-voles ever
carry their offspring about in this manner I have been
unable to ascertain.

It is stated, however, on good authority, that the
young hippopotamus is often carried on the back of its
mother as she swims, although it is somewhat difficult
to imagine how the little creature can maintain a
secure foothold on such a slippery surface. Be this as
it may, it is evident that the hippo, even though larger

HiK. 2. — Female Opossum

-.jd Vojnif. From Elliot's "Mail
Middle America.")

than a good-sized boy, cannot be much of a burden to
its colossal parent. A creature which habitually
carries about its offspring on its back is the female
koala (Phascolarctiis koala), the native bear of the
Australian colonists, which dwells among the highest
branches of the lofty blue gum-trees, where it may be
descried on moonlight nights by a practised observer
when thus loaded (Fig. 3). The thick woolly coat of the
parent affords excellent foothold to the young koala ;
and since there appears to be never more than one of
the latter, the burden to the female cannot be excessive.
The koala is a member of the marsupial order, in all
the species of which the young are born in a helpless
condition, and cling for some time to the nipples of
the parent. After this they are usually carried for a
period in the pouch in which the nipples are situated.
The sojourn of the young koala in the pouch after
leaving the nipple, if it takes place at all, must, how-
ever, be very short, as the creature takes a seat on the
maternal back while still small.

The American opossums are likewise members of the
marsupial order, but they present some very remark-
able variations in regard to the development of the
pouch. The common or typical species, for example,
takes its name of Didelphyi marsupialis from the pre-
sence in the female of a large and capacious pouch, in
which the numerous members of the family are carried
about until they attain a very considerable size and
become a serious hindrance to the parent in getting
about. On the other hand, in the above-mentioned
South American species, commonly known as the
thick-tailed opossum (D. crass icaitdata), and likewise
in the much smaller D. darsigtra, the pouch is rudi-
mentary and functionless, and the young arc carried

about on the back of the female parent in the manner
alreadv described. Considering that all three species
are thoroughly arboreal in their habits, the reason for
the loss of the pouch in the two latter seems altogether
inexplicable. If the female of one species can climb
with her pouch full of young, there is no apparent
reason whv those of all the species should not be al)le
to do the same; and so far as the young are concerned,
they would seem, at all events in the younger stages
of their existence, much better off in a nice warm
pouch than in a somewhat precarious and decidedly
exposed position on their parent's back, where, how-
ever, they have much better opportunities of seeing
somethintr of the world.

Fijf. 3. — Female Koala carrying its Cub.

The females of all the species of kangaroos,
wallabies, and rat-kangaroos always carry their off-
spring in the pouch until they are of very considerable
size and quite able to look after themselves. In most
cases there is only a single young one, but a second
may be born before the first has quitted the pouch.
In the case of the larger kangaroos, the young, or
■• Joey," which may be the size of a hare before it
finally leaves the pouch, must be a very serious burden
to the female when at speed. This is proved by the
fact that although when first pursued the female parent
will pick up and deposit in the pouch the " Joey "
running by her side, yet that when very hard pressed
she will not hesitate to eject her offspring and leave it
to its fate in the hope of saving her own life.

The cuscuses of the Austro-Malayan islands and the
phalangers — the mis-called opossums — of Australia it-
self, which are thoroughly arboreal creatures, all carry
their young in pouches. Although there may occa-
sionally be twins, as a rule there is but one at a birth,
.so that the mother is not burdened to any excessive
extent by her load. Of the breeding habits of the
flying-phalangers, or flying-opossums, of Australia,
little or nothing seems to have been recorded; but
since they have pouches, it may be assumed that
the young, which arc frequently four in number, are
carried about by the female. As to the pigmy flying-
phalangers— the flying-mice of the colonists — it is diffi-

May, 1905.

KNOWLEDGE & SCIENTIFIC NEWS.

107

cult to know what to say in this connection, as an
anonymous writer tells of having seen a family of
young ones cut out of a hollow tree without mention-
ing whether or no they were in the maternal pouch.
On the other hand, the bandicoots {Pcramclcs) and the
native cats, or dasyures (Dasyurus), invariably carry
their young about in the pouch, although in some of
the species of the latter group the offspring make
use of that shelter only for a very short period
after they have detached themselves from the nipples.
Not unfrequently there are six in a litter. Although
the members of the Australian genus Fhascologah are
commonly called pouched mice, they scarcely deserve
that title, since the pouch is generally reduced to a
mere fold in the skin of the under-parts, and the young
hold on to their mother mainly by the aid of her long
hair, in which they are more or less completely con-
cealed. From eight to ten young ones have been seen
clinging to the nipples of their parents; but how long
after being able to move about by themselves they
cling to the maternal body, and what proportion the
united weight of a litter bears to that of the parent, do
not appear to have been recorded. Eight or ten
little ones, of whatever size, must, however, be a
considerable load for a creature no bigger than an
ordinary mouse, so that these little marsupials are
certainly entitled to be included in the list of heavily-
burdened mothers. There are other Australian mar-
supials which carry their young in the pouch, but
these need not be specially mentioned. On the other
hand, in the curious banded anteater [Myrmccobius
fascla/us) the pouch is obsolete, and the young, after
becoming detached from the nipples, are probably
brought up in some hollow tree. On this point, as
well as many others connected with the breeding of
marsupials, we are, however, sadly in need of definite
information. And here it may be mentioned that few
of the numerous collectors who are now sent to all parts
of the world to obtain specimens of animals bring back
any information with regard to their habits ; their sole
object being to kill as many innocent and beautiful
creatures as possible, and thus add a few more names
to the already overburdened list of species and sub-
species. The infinitely more important life-histories of
the creatures are left alone. This is a great pity, for,
without in any way decrying the importance of
systematic and anatomical investigations, the life-
histories of animals undoubtedly deserve our best at-
tention.

Another Australian mammal, the spiny anteater
(Echidna aculcata), must receive special mention here,
since it is one of the egg-laying group, and during the
breeding season the female carries her two eggs about
with her in a temporary pouch till they are hatched.
In what stage of development the young are hatched
does not, however, seem to be ascertained, neither
does there appear to be any information with regard
to the length of their sojourn in the pouch after hatch-
ing.

We have already seen that bats of all kinds habitu-
ally carry their young about them until sufficiently
old to fly by themselves; and it is obvious that all
flying mammals must either follow this practice, or
keep their young in nests to which periodical visits
are paid. The flying-squirrels (not the marsupials
wrongly so-called), which, by the way, do not really
fly, but merely take long flying leaps by the aid of the
parachute-like expansion of the skin of the flanks,
adopt the former plan. On the other hand, the curi-
ous flying-lemurs, or cobegos {GaleopUhccus), of the

Malay countries and the Philippines, which also merely
take flying leaps, carry their young about with them
in the same manner as bats. Dr. A. R. Wallace, for
instance, describes shooting a female cobego, to whose
breast adhered a small, blind, and naked young one,
which reminded the observer of the helpless offspring
of marsupials, although it was in a somewhat more
developed condition. How long the young cobego
makes use of its parent as a kind of flying-machine,
and to what extent the mother is hampered by the
weight of her offspring, are, however, interesting
points in regard to which we have again to deplore a
total lack of information.

The only other mammals that habitually carry their
young are the members of the order Primates, which
includes the human species, apes, monkeys, and
lemurs. Among these, except when the task is
delegated to the husband, the nursemaid, or the
perambulator, the practice is universal on the part of
the female ; the male apparently never taking upon
himself the duties of nurse among mammals other than
man. In the case of monkeys and apes the young
appear to be generally carried clinging to the breast
of their mother or on her back. Some of the lemurs

Fig. 4.— Female Lemur and her Baby. (From .Sclater, Troc. Zool. Soc.)

at any rate have, however, an altogether peculiar
method of carrying their living burden, the young
lying transversely across the abdomen of the female
parent, with its head on one flank and its tail on the
other (Fig. 4). In this strange position the baby lemur
is probably carried with less inconvenience than would
be the case in any other way; and since the young of
these animals appear to be thus carried till they are
of comparatively large size, such a consideration is of
considerable importance.

In conclusion, it may be mentioned that two points
are brought into prominent notice in this article.
Firstly, the wonderful amount of care the mothers of
many species of mammals devote to the well-being of
their offspring, and the amount of physical labour and
endurance they are willing to undergo for this object.
Secondly, the extremely imperfect state of our know-
ledge with regard to the breeding habits of many of
the species noticed in the foregoing paragraphs, and
the urgent need that exists for careful observation on
these and other habits if zoology is to be raised to
something more than a mere catalogue of species and
description of anatomical details.

io8

KNOWLEDGE & SCIENTIFIC NEWS.

[May, 1905.

ASTRONOMICAL.

Ne>v Comet 1905ia) Giacobini.

A TELEGRAM rectived on the 27th March from the Kiel

CcDtralstelle announced the discovery of a new comet at

Nice, on the 26th March, by M. Giacobini, for which the

followirg co-ordinates have beeu furnished : —

RA. = 86- 3' 30" (5 b. 44 m. 14s.) i_ 1905. March 26 12. Sh.n-8m.

Decl. = + 10= 56' 56" ) Nice Mean Time.

A later telegram confirmed the discovery by the comet being

seen at Lick on March 27 in the position : —

RA. = 5 b. 48 m. 55s. I 1905. March 27. 7 h. 57 i m.
Decl. = + 12° 35' 43" » (Lick Mean Time.)

The observations indicate that the comet, on discovery, was
situated in the North-East of the constellation of Orion,
between the stars a and 7, and that it is moving in a north-
easterly direction at the following rate: —

Daily molion in RA. = -f 45'

Decl. = + 1° 15'

From the observations obtained on March 26, 28, and 30,
the following Ephemeris elements have been computed by
Herr E. Stromgren.

T = 1905, April 3-2098 (Berlin Mean Time).
« = 357' 9'49 )
fi = 156- 7'-94 - (1905 o)
«' = 4i°37'4« '
log q = o 05232.

Photoeraphy of the Solar Corona in
Daylight.

For many years astronomers in all parts of the world have
been experimenting with various devices in the endeavour to
obtain records of the solar corona at ordinary times, hut with-
out success. ^L A. Hansky has during the last four years been
pursuing this inquiry in the exceptionally favourable atmo-
sphere at the summit of Mont Blanc. He found by preliminary
trials that the spectrum of the diffused sky light was very
feeble in the red region compared with the intensity of the
green and yellow portions. It is a fortunate condition that in
the solar spectrum the red rays are relatively less absorbed in
their passage through our atmosphere than the more refrangible
rays ; and as the continuous spectrum of the corona is very
intense in the red region, it appeared feasible to attempt photo-
graphy of thecorooal structures by meansof these red radiations,
obtaining the necessary contrast by passing the light through
a screen suitably prepared to cut off all except the red rays.
After numerous tests of many aniline dyes in solution, a com-
bination was found which completely absorbed all the spectrum
radiations from X 6600 to the extreme ultra violet, the colours
used being red, orange, malachite green, and gentian violet.
The absorbing screens were made by steeping fine grained
Lumicre films, previously fixed without development, in con-
centrated solutions of the corresponding colours. These were
then placed between two glass plates, one with plane parallel
faces, the other coated with the usual sensitive emulsion.

An opaque screen slightly larger than the diameter of the
solar image was placed on the outer glass plate, so that the
light from the brilliant photosphere was prevented from reach-
ing the sensitive plate.

By the permission of M. Janssen, the photographs were
made with the 12-inch telescope of the Mont Hlanc observa-
tory. On September 3, 1904, twelve photographs were obtained
of the circumsolar regions, with exposures varying from
30 seconds to 2 minutes. The positions of the screens were

changed so as to eliminate any local effects due to them on the
plates. The negatives obtained were copied and secondary
negatives obtained by intensification, giving increased contrast,
which are stated to show remarkable resemblance to those of
the solar corona photographed during total eclipses.

M. Janssen adds a few words in support of the forms thus
photographed being truly coronal, and M. Hansky suggests
that by a suitable alteration in the colour of the screen used,
it may be possible to photograph the images of the prominences
in the red light of wave length of the C line of hydrogen.

In a short criticism of this work of Hansky, M. H. Deslandres
suggests that it would be a great improvement if special pre-
cautions were taken to eliminate the diffused light in the photo-
graphic instrument itself. In the apparatus as used, light
would be reflected back from the disc cutting out the sun's
direct image to the surfaces of the objective, and from these
some light must necessarily be again irregularly reflected
towards the photographic plate, where it will tend to produce
a diffused glow round the edge of the occulting disc. The
direct solar radiation is estimated to be about 200,000 times
as intense as that of the corona, and if we assume the irregu-
larly reflected and diffused sunlight from the occulting disc
and object-glass surfaces to be i-iooth part, it is evident that
this would still be far stronger than the corona it is desired to
photograph. It is suggested that the occulting screen be
placed outside the iuEtrument altogether, at such a distance
that it will obscure the sun's disc and also a slight amount of
the more intense base of the corona.

Search Ephemeris for Tempel's Periodic
Comet. 1867 II.

It being probable that the periodic comet discovered by
Tempel in 1867, and afterwards observed in 1873 and 1879,
may return during the present year, M. K. Gautier has pre-
pared a provisional search ephemeris to aid in its identifica-
tion. There appears to be evidence that the perihelion dis-
tance of the comet has been considerably increased by the
perturbations induced by Jupiter, the element being almost
double its former value in 1867. This factor will probably
cause a great diminution in the intrinsic brightness of the
comet. It is hoped, however, that the favourable conditions of
the coming apparition may permit of its observation ; perihe-
lion passage occurs in the spring, a little before opposition.
There is a slight uncertainty of + 12 days in the epoch of
perihelion passage, and the ephemeris is therefore given for
each of the extreme times in addition to the more probable
mean values. The following are the elements on which the
ephemeris co-ordinates are based : —

T = 1905 April 20'5 Berlin mean time.

fi = 542"-68.

0 = 23^42'-o.

1 = 10" 47''2.

n = 72'= 4i'7.

u) = i68' 4o'-3. )
For preliminary purposes until the comet be sighted it will
be suflicient to give the positions for every fourth day.

Ephemeris for Berlin mean MiiliiiglU.

(mean equinox \
1905. /

T = May 2-5

T = April 20-5

T = April 8'5

1905.

R.A.

Decl.

R.A.

Decl.

H.A.

Decl.

H. M. S.

0 .

H. M. S.

0 .

H. M.S.

0 ,

May—

'7 9 55

-19 146

17 40 58

-21 i6'5

18 10 31

-22 48*1

6-5

9 '3

39'7

41 13

43-4

II 44

23 151

lO's

8 1

20 58

40 56

22 II-4

12 25

435

«4'5

6 zo

32'9

40 8

40-4

>2 33

24 '3'3

185

4 >4

21 o'7

38 50

23 103

12 9

441

22-5

» 45

28-9

37 4

40 9

II 13

25 i6'o

26'5

16 58 58

574

34 52

24 II-9

9 48

485

30'5

55 57

22 26'0

32 18

43"0

7 53

26 21 5

June —

52 48

543

29 26

25 >3'9

5 34

545

49 37

23 22-2

26 22

442

2 54

27 27- I

"■5

46 29

494

23 II

26 13-5

'7 59 58

589

•55

16 43 30

-24 •5-9

17 19 59

-26 41 "6

17 56 50

-28 29 5

Mav, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

109

CHEMICAL.

By C. A. Mitchell, B.A. (Oxon.l, F.I.C,

ApplicaLtion of the Serum Test to
Mximmies.

Dr. Uhlenhut, of the Hygienic Institute of Greifswald, has
attempted to determine the origin of mummy material by
means of the specific serum test of which a description was
given in " Knowledge & Scientific News " (this vol.,
p. 86). For this purpose aqueous extracts were made
of a large number of mummies ranging from 1000 to
3000 years in age. It was found that these were strongly
acid and gave a turbidity with normal rabbits' serum, but that
when the acidity was neutralised they gave no reaction either
with normal serum or with the pracipitiiics that had been
rendered specific for human or other serum. This was even-
tually shown to be due to the fact that these extracts did not
contain any albuminous substances, which if still present ir.
the mummies were no longer soluble in water. On the other
hand, mummies of comparatively recent date (up to 66 years)
yielded extracts that at once showed their origin by giving
pronounced precipitates with specific sera.

* * ■»

Ancient British Gunpowder.

In the course of excavations made at the beginning of this
year in the public square of St. Martin-de-Ke (Charente
Inferieur) the workmen unearthed trenches in which lay
skeletons, presumably of those who fell when the town was
besieged by the English in 1627. Among the debris was found
a spherical iron bomb containing a moist black powder, which
had been fired by the besiegers and had failed to explode.
The powder, of which a specimen has been examined by M. L.
Desvergnes, ignited readily after being dried, and was found to
consist of about a third of nitre, a third of carbon, and a fifth
of sulphur, the remainder being iron oxide derived from the
rusting of the iron shell. After making allowance for this iron
oxide and for the fact that a large proportion of the nitre must
have been dissolved out by the water, these analytical results
are in agreement with the composition of old English military
gunpowder, which contained approximately 75 parts of nitre,
15 parts of carbon, and 10 parts of sulphur.

* * *

The Phosphorescence of Phosphorus.

Recent experiments made by Herr Jungfieisch show that the
phosphorescence of phosphorus is due to the formation of an
oxide. Thus if an inert gas such as nitrogen be passed over
phosphorus contained in a vessel the vapour issuing into the
air is only faintly luminous, but the admission of a minute
trace of oxygen with the gas causes the phosphorus to phos-
phoresce and enormously increases the luminosity of the
vapour. The oxide can be condensed by cold, for phosphorus
vapour is rendered non-luminous by being passed through a
vessel cooled to 50° F., while an inert gas sulasequently passed
through this vessel at a temperature of 60 F. becomes phos-
phorescent.

* * *

Luminescent Zinc Blende.

2inc blende which possesses the curious property of
luminescence has been discovered in California, Nevada, and
other States of North America. The ore has a flaky structure,
and varies in colour from light to dark grey. It consists, in
the main, of a mixture of white baritejbarium sulphate) and
brown sphalerite (zinc blende), and also contains a consider-
able amount of gold and about 4 ozs. of silver per ton. It is
not radio-active, but when scratched with a knife in the dark
emits a series of sparks forming a line of light which follows
the point of the blade.

* * *

Oxydases and their Work.

Everyone is familiar with the discoloration that takes place
in a cut apple or potato on exposure to the air, and there are
many analogous phenomena in the vegetable world. Thus
several species of fungi, such as Boletus luridus, turn blue when
broken, whilst beetroot rapidly darkens under the same con-

ditions. In each case such changes are to be attributed to the
oxidation of certain constituents within the plant, a combina-
tion with the oxygen of the air being brought about through
the agency of certain organised ferments or enzymes termed
oxydases. An enzyme may be defined as the material sub-
stratum of a peculiar form of energy produced by living cells,
trom which it is more or less separable. Oxydases, like other
enzymes, such as the pepsin of the gastric juice, and the (fms/rtst's
of the saliva and of malt which convert starch into sugar, have
not yet been isolated in a pure condition. Impure solid pre-
parations have been obtained by treating the juice of the plant
with alcohol and subjecting the precipitate to further purifica-
tion. MM. Chodat and Bach have recently prepared very
active and relatively pure oxydases from different fungi, &c.,
and find that they are not albuminous substances. The
activity of oxydases is destroyed by heat, and thus a baked
apple or boiled potato can be exposed to the air without
darkening in colour. A general test employed to detect oxy-
dases is based upon their behaviour with gum guaiacum
tincture. Some, the direct oxydases, cause it to turn blue by
combination with atmospheric oxygen, while others, terrrjcd
indirect oxydases, only give the blue coloration when hydrogen
peroxide is also present. This reaction is employed by M. E.
Payet as a means of distinguishing between gum arable and
gum tragacanth. The former contains an oxydase and gives
the blue coloration, while the latter produces no effect upon
the guaiacum tincture. Oxydases are also produced by animal
cells. Thus they have been detected in milk, in blood, in
saliva, in the gills of the oyster and other molluscs and in the
internal organs of many animals; and Dr. Dubois attributes
the phosphorescence of the glow worm or other animals to the
action of an oxydase, to which he gives the poetic name of
liicijerase.

GEOLOGICAL.

By Edward A. Martin. F.G.S.

Oscillattions of Shore-Lines.

Glacialists will feel considerable interest in Dr. Nansen's
paper on this subject, which he read before the members of the
Research Department of the Royal Geographical Society.
Most of his illustrations appear to have been drawn from
recent vertical movements of the Norwegian coast. This is, of
course, closely bound up with the history of the Glacial Period,
and apparently he has no difficulty in subscribing to the views
of most modern geologists as to the great downward move-
ment which occurred, at the greatest period of glaciation, in
northern and north-western Europe, and if this view once
be universally accepted we need go no farther for an explana-
tion of the arctic-shell-bearing beds, which have been found at
1400 feet above the sea, and at lesser heights, at Moel Tryfaen,
Gloppa, Macclesfield, and other places. It would be interest-
ing to know how he views the suggestion, admittedly to some
extent borne out by observations made during the last few
years in Spitzbergen, that these shell beds were pushed or
floated upward by ice, the molluscs not having themselves
actually lived in situ.

Dr. Nansen stated that 42 per cent, of the continental sur-
face of the earth stands between 600 feet above and 600 feet
below sea-level, and adduces this fact to maintain that during
a long geological period shore-lines have been at very much
the same level as now. But though the coast line of Norway
had been depressed in places 700 feet below its present level,
in Dr. Nansen's opinion, because the land had been pressed
down by the weight of the great ice-cap, yet in other places
the depression had been very much less, viz., 30 feet to 60 feet.
It was remarkable, however, that the laud appeared to have a
tendency to a certain mean position of equilibrium ; and that,
in spite of this great difference in the amount of depression,
the coast had afterwards come to be at almost exactly the
same level as that at which it stood previous to depression.
On the subject of an actual rising of the surface of the ocean
during recent geological times a decision must be postponed
for the production of future evidence. An accumulation of
ice around the North Pole might so shift the centre of gravity
of the earth as to cause a rise of the ocean around our coasts.
If, now that the Glacial Period is long past and gone, there

KNOWLEDGE & SCIENTIFIC NEWS.

[May, 1905.

remains a rise in the level of the ocean, then presumably the
tail-end of that period still remains, and there is now more ice
in Arctic regions than there was in those times immediately
preceding the period. This is to some extent borne out, of
course, by the lossil plant-remains of tertiary age, which have
been found within the .-Vrctic circle.

* * *

Drift Deposits.

In a paper on the Superficial Deposits of Central and
Southern England, Dr. .-\. E. Salter, F.G.S., has summarised
the various drift deposits over the area mentioned. The re-
print of the paper, which was read before the Geologists" Asso-
ciation, will prove of great use to students of these surface
accumulations. I should like to see more attention paid to
the Merstham Gap in the North Downs, for, although the
stream which cut it before the Weald was denuded has long
been captured by the Mole, there is no doubt that the two
intermittent bournes, from the gap, and along the Catcrham
\'allcy, represent all that is left of the river system of which
the Merstham Gap is the chief visible work. Prestwich's
thin covering of eravel at " West Ho, near Norwood,"
referred toby Dr. Salter, is much thicker than he knew. I have
described elsewhere the gravel which extends from Westow
Hill, Upper Norwood, south to Grange flill, and some reputed
palajoliths, and, according to some geologists, eoliths, have lieen
found in sub-angular gravel at the top of South Norwood Hill,
at 370 feet O. D. The high-level gravels of L'pper Norwood
are an important geological feature of days contemporary, I
believe, with the existence of the arch of the great Wcalden
anticline.

* * ♦

Geological Maps and Samples.

Geologists may perhaps be interested in knowini,' that
geological maps can now be ordered at most of the large post
offices in London, as well as at head otTices in the Provinces.
Indexes and small specimen maps are kept at upwards of 700
head post offices throughout the country. The foreign sample
post is an excellent medium for the transmission of geological
fpecimens to and from abroad, natural history specimens,
generally, being allowed by the authorities at the cheap rate of
4 ounces for one penny, when prepaid within the United
Kingdom They must not, however, be sent as articles of
commerce.

* • •

Coa.l-Meas\ire Classificatiorv.

On April ijth, a paper was read before the Geological
Society of London by Mr. Robert Kideston, E.G.S., on " The
Divisions and Correlation of the Upper Portion of the Coal-
Measures." A new classification was proposed, by which the
Upper Coal Measures were to be known as the Radstockian
Series, a Transition Series as the Staffordian Series, the M iddle
Coal-Measures as the Westphalian Serie.s, and the Lower
Coal- Measures and Millstone grit as the Lanarkian Series.
The proposed substitntion of new terms for those which have
obtained hitherto did not meet with much approval, and we
sympathise with the protest which was made ag.iinst the in-
troduction of new terms, except under conditions of the
strongest necessity.

« « «

The Phosphatic Chalk at Taplow.

A further paper read at the same meeting dealt with the
" Age and Relations of the Phosphatic Chalk of Taplow," by
H. J. O. Whiie, F.G.S., and Llewellyn Treacher, K.G.S. The
rocks were described in detail, and the following clas.sification
was adopted : —

Feet.
E. Upper White Chalk . . . . (visible) 16
D. (j'pper Brown Chalk, or rich phosphatic

band about 8

C. Middle White Chalk .. ,, lO

B. Lower Brown Chalk, or rich phosphatic

band . . about 4

A. I^wer White Chalk .. (visible) 17

The Lower White Chalk includes a thin layer of tabular
flint and one of elongated nodular flints. ,-ind the first signs
of phosphatic materi.d were observed a few inchi-s below the
tabular seam. Attention was drawn to the presence of phos-
phatic nodules and concretions at certain horizons; and the

authors concluded that the Lower White Chalk belongs to the
zone of Micrasti^r cor-aiiguinum, and the succeeding beds to
that of Marsul<ites tcstudiimrius ; while the lower phosphate-
band represents the lower part of the t'i';i/iJfn')iHS-band, and
the upper one that of the Marsupitcs-haxiA of that zone. In
each phosphate-band the base is quite sharp, being defined by
a rock-bed in the Chalk ; but the upper limit is very ill-
marked. The Middle \\'hite Chalk is in part divided into
lenticles with slickensidcd surfaces. The authors found
ActiiiPciiniiix rcnis in B, and A.gnnuilatus in D and E, but not
.! . quadi-atui in any bed. Phosphatization is not confined to
the foraminifera, and other microscopic remains, but occurs in
all shells and structures which are readily penetrable, although
not so markedly in those of a more homogeneous character.
Scalaria occurs in division E, the upper part of which may
possibly just include the base of the zone of Actiiiocamax quad-
mills, or at any rate may not be many feet below that base.
The distribution, numerical proportion, and, to some extent
also, the morphological character of the microscopic fossils
of the Phosphatic Chalk are exceptional. The authors of the
papers think that a part, at least, of the phosphatized material
has acquired its distincti\e mineralogical character on the
spot. So far as can be ascertained from existing data, the
Phosphatic Chalk is confined to a small tract of country
measuring less than 3.V miles from north-east to south-west
by less th.an i mile from north-west to south-east.

OR.NITHOLOGICAL.

By W. P. I'vcRAiT, A.L.S., F.Z.S., M.B.O.U., &c.

The Doom of the Penguin.

The Penguins of Macquarie Island and the desolate Auck-
lands are in danger of extermination at the hands of the
company promoter, and this fate will certainly overtake them
unless steps are taken to save them.

Dr. E. A. Wilson points out that for some years past a
considerable trade has gone on in the preparation of penguin
oil, which is obtained by casting these unfortunate birds by
the thousand into the melting-pot and boiling them down. No
less than 100 tons of oil so procured has recently been placed
on the market. Encouraged by success, a scheme is now afoot
whereby cauldrons are to be set upon the Auckland Islands to
facilitate this nefarious traffic. Hitherto the " rookeries " of
these Islands have suffered comparatively little; but once the
cauldron fires are lighted they will not be allowed to die out
till the last survivor of the host has been tlung into the
seething broth. Surely no effort should be spared to frustrate
this diabolical scheme.

« ♦ »

A Great Egg Collection.

Our oological readers will be glad to know that Mr. Radcliffe
Saunders has just presented his collection of 10,000 eggs to
the Natural History Museum at South Kensington. This is
the second donation of 10,000 eggs that Mr. Saunders has
sent to the Museum. His last gift includes many rarities.
The Raptorial series is complete, and so also is that of the
crows, crossbills, and buntings. The collection of cuckoos'
eggs (Ciiciiliis cauorus) is especially fine, numbering over 300
specimens. Their value is greatly enhanced by the fact that
they have in every case been preserved with those of the
hosts destined to hatch them.

The generosity displayed by Mr. Saunders cannot be easily
over-estimated. He has placed at the disposal of oologiststhe
world over a collection brought together with the most exact-
ing surveillance. Till now, only a favoured few could derive
any profit from these labours — henceforth all may benefit who

Hairy Waterhen at Bury St. Edmunds.

The /odliif^iil, for March, records the capture of one of
those curious variations of the waterhen which occurs from
time to time, wherein the feathers acquire a peculiarly loose
structure, comparable to that which obtains in Ratite
birds. In colour, this bird, as in other cases of this kind, is
described as of a warm sandy-brown above, and greyish-white

May, 1905

KNOWLEDGE & SCIENTIFIC NEWS.

beneath. The head and throat were normal both as to colour
and the structure of the feathers. The bird was killed in
January last, and is described as immature.

This makes the thirteenth recorded instance of this varia-
tion in the water-hen. So far, m really satisfactory explanation
has been given of this curious " sport." Microscopic e.xami-
nation of the feathers shows that they are always much
abraded, the tips of the shafts being broken off. The loose
character of the feathers is due to the absence of barbules.

Partially '' hairy " varieties of this type have been recorded
in hawks and gulls, and in the case of a jacana and a grey
Brahma hen.

Should any of our readers come across a similar variation
of ^this kind in a freshly-killed specimen, we would suggest
that a careful note should be taken of the colour of the eyes,
skin, and bones.

* » »

Arrival of Summer Birds,

From the FiVW, April 15, we gather the following: —

Ring Ousel .... Windermere, April 5.

Blackcap .... Wellington College, Berks, .\pril g.

„ .... Mitcham, Surrey. April 13.

Wryneck Ray leigh, Essex, April i.

Whitethroat . . Tooting Common, .-Vpril 11.

Redstart „ „ April 12.

Swallow Exeter, March 23.

., Upwey, Dorset, April i.

Kettering, April i.

,, Eastbourne, April i.

Martin Kettering, April i.

Willow-wren . . . Tooting rommon, .'^pril i.

,, ... Walsall, April i.

i-JC'Cuckoo .... Horsham, April I.

„ .... Beaminster, Dorset, .\pril i.

Yellow wagtail . . Axminster, March 1 1.

.;., Tree-pipit .... Wellington, April 4.

Stone Curlew . . . Warminster, March 27.

Common Sandpiper . Near Builth, April 4.

ZOOLOGICAL.

By R. Lydekker.

The Subterracnean Texas Sala.ma.nder.

Ele\'F.n years ago several specimens of a very curious blind
salamander were thrown up from a great depth by an artesian
well in Texas, and were subsequently described as repre-
senting a new genus and species under the name of Typliloinolgc
rathhuni. Hitherto they have been generally regarded as re-
lated to the blind proteus, or olm, of the subterranean waters
of Carniolo, whose habits were so well described years ago by
Sir Humphry Davy. A lady worker. Miss Emerson, writing in
the Proceedings of the Boston (U.S.A.) Natural History
Society, has, however, come to the conclusion that this is a
mistake, and that the creature (which she regards as a per-
sistent larval form like the axolotl) is really a cousin of the
common .American salamanders of the genus spelcrpes. So
much for external resemblances.

* » *

Miscellaneous Items.

According to a French naturalist, Mr. H. G. de Kerville, an
Indian palm-civet {Paradoxunts hermapliroditus) recently lived
for a year and a half in a forest in Normandy. The creature
had in all probability escaped from a passing ship, but it is
certainly remarkable that such an essentially tropical animal
should have made itself so thoroughly at home in this part of
Europe. The new Orkney vole continues to attract much
interest on the part of naturalists, Messrs. Clarke and Bradley
discussing its affinities in the January number of the Annah
of Scottish Natural History; while Dr. Forsyth- Major gives his
views in the March issue of the Annals and Magazine of Natural
History. The two views do not, however, altogether agree, the
first paper suggesting that the creature is in some respects
intermediate between the water-vole and the field-vole ; while
in the second it is urged that its relationships are solely with

the latter and its Continental representative. In the Zoologist
for .April the present writer describes two new species of
Oriental gorals, or goat-like antelopes, the one from the
Western Himalaya, and the other from Burma.

* * *

Skeleton of the Oka.pi.

A recent issue of the Bulletin of the Malacological Society of
Belgium contains a figure and description of the skeleton of a
male okapi which has just been mounted for the museum at
Antwerp. The structure of this skeleton is said to indicate an
animal adapted to live in thick forest, and whose body can
pass between tree trunks separated only by a very narrow
space. .\11 this is perfectly in harmony with the description
which appeared not long ago in a German periodical of the
natural haunts of the oLnpi.

* * *

Papers Read.

At the meeting of the Zoological Society on March 21st,
Mr. R. I. Pocock read a paper on the effects of certain
abnormal conditions on the horns of the .American prongbuck,
or prong-horned antelope, in captivity. On the same occasion
Sir H. H. Johnston discussed the mammals and birds of
Liberia, poinling out that although this district was closely
connected with Sierra Leone on the one hand and with the
Ivory Coast on the other, yet that it seemed to possess certain
peculiarities of its own with regard to fauna and flora. Mr.
M. A. C. Hinton, at the same meeting, described certain sub-
fossil red deer antlers ; while Dr. R. Brown contributed notes
on the affinities of the extinct South African reptile Procolophon.
At the meeting of the same Society on April iSth, the follow-
ing three papers were down for reading, viz., Mr. A. E. Shipley
on entoparasites from the Zoological Gardens and elsewhere.
Dr. E. Lijnnberg on hybrids between the common and the
mountain hare from Southern Sweden, and Mr. R. H. Burne
on the anatomy of the leathery turtle, or luth.

REVIEWS OF BOOKS.

Neolithic Dew-Ponds and Cattle-Ways, bv A. J. Hubbard.
M.D., and George Hubbard, F.S.A., F.K.LB.A. Pp. 71. 25
illustrations. (Longmans, Green, and Co.) Price 3s. 5d.
net. In this thin small-quarto the authors deal with the
evidence which we have of prehistoric man in England in
certain well-known dew-ponds, and in the cattle-wavs, some-
times made by human hands and sometimes probably by
wild cattle themselves, which lead to certain recognised
watering-places. The book deals more particularly with con-
siderations concerning Cissbury, Chanctonbury, and Maum-
bury Kings, Maiden Castle, near Dorchester, Ogbury Camp,
and Figsbury King. We are not sure the authors are alto-
gether justified in applying the term "neolithic" to all of
them, and we think the balance of probabilities goes to show
that Stonehenge is just as likely to be of neolithic workman-
ship as any of the great earth-embankments and trenches to
which the authors refer. We cannot agree in assigning so
recent a date to Stonehenge as iSoo b.c. The authors have
been at great patience in tracing out what remains of the
great Rings with which they deal, although they make no
claun to have treated the subject exhaustively. Olher well-
known Rings will perhaps be dealt with at some future date.
The book is fully illustrated, and many of the photographic
reproductions are full-plate, and admirably illustrate the text.

The subject of the formation of dew- ponds is interesting, and
the authors are apparently correct in assigning a great age to
them. We are told that in this country there is at least one
wandering gang of men, who will construct for the modern
farmer a dew-pond, which will contain more water in the heat
of summer than during the winter rains. The space hollowed
out for the purpose is first thickly covered with a coating of
dry straw. The straw is in turn covered by well-chosen, finely-
puddled clay, and the upper surface of the clay is then closely
strewn with stones. The margin of the straw has to be effec-
tually protected by clay, since if it become wet it will cease to
attract the dew, as it ceases to act as a non-conductor of heat
and becomes o£ the same temperature as the surrounding

KNOWLEDGE & SCIENTIFIC NEWS.

[May, 1905.

eartb. The puddled clay is chilled by the process of evapora-
tion, and the dry straw prevents the heat of the earth after a
hot day from wanning the clay.

We remember hearing some time ago that a well-known pro-
fessor was accumulating; material for a book on ■' dew-ponds,"
but the work is apparently yet in the future. The manner of
their formation, as shown in the book under review, is a distinct
contribution to science. There appears every evidence to
show that many of the ringed embankments and clusters of
artificially-planted trees were connected with the worship of
the sun, and this connection might well be worked out
thoroughly. We are not sure that the authors have not built
up rather much upon little, in seeing the former existence of
watch-houses and guard-houses in what are merely depressions
in the ground. That the Romans utilised the embankments
in many instances we have evidence in the tiles and other
remains which have been discovered on the sites. We have
doubts as to the amount of protection which the embankments
gave to men and cattle from wolves or human enemies. Thev
would serve to conceal their occupants, but would they not
also serve to conceal the enemy, whatever it was. when it
came ? In some cases the earth-walls would be far more
serviceable in protecting half-naked men and women from the
biting winds which cut across the downs and are practically
always blowing. This is frequently overlooked. In conclu-
sion, we would refer to the plate on page 6g, and would point
out that what look like cattle-tracks may be merely caused by
the slipping of claywith-flints upon the chalk. When over-
grown with tufts of grass, this has a tendency to form long
terraces, and in the distance these sometimes look like a series
of step-like tracks. E. A. M.

Resistance o( Air and the Question of Flying, by Arnold
Samuelson (Spon) ; price, 2S. net. — This is a work of consider-
able value, not so much for the information contained within
it as for the suggestions which may be brought to mind on
reading it. It is one of the very few books which have been
written recently on this subject, and gives in concise form
many of the latest theories and facts concerning it. But the
reader must not take for granted all the statements here made.
Many of them are but opinions held by the author, and not
shared by other authorities. In fact, he states ; " I dare not
expect that the whole world will at once agree with me,"
although he lays down dogmatic assertions which might easily
mislead those anxious to learn. The author is, of course,
German, and the main portion of the pamphlet consists of a
lecture delivered by him. presumably in Hamburg. It is a
pity that the MS. was not looked over by an Englishman, as
there are many expressions and sentences which are a little
obscure.

Report of the Bureau of American Ethnology, 1900-1901;
parts I and 2. (Washington : Government Printing Office.). —
1 hese splendid volumes, profusely illustrated with coloured
and other plates, exhibit a thoroughness of detail and pains-
taking work such as is seldom seen in these days of hurried
production. The report consists chiefly of three " papers,"
the nature of which may be gathered when we say that the
first, "Two Summers' Work in Pueblo Ruins," by Jesse Walter
Fewkes, con.sists of 195 large pages with 122 illustrations in
the text, and no less than 70 beautifully-executed full-page
plates. The other two papers, " Mayan Calendar Systems,"
by Cyrus Thomas, and " Hako, a Pawnee Ceremony," by
Alice C. Fletcher, are almost as long and complete. The first
paper comprises the report of archaological field work con-
ducted at a ruin called Homolobi, near Winslow, Arizona, and
later at ruins on the Little Colorado River, and at Chaves
Pass and other places. A large number, in all 1824 objects,
were collected from the excavations, mostly of a mortuary
nature from the cemeteries, about half of which were preserved
entire, and many of the others in pieces which could be satis-
factorily joined together. These objects include vases and
bowls of pottery, shell and stone ornaments, bone implements,
matting and basketr)-, stone implements, &c. The illustra-
tions comprise photographs of ruins and coloured representa-
tions of the pottery and other objects. The paper on the
" Mayan Calendar Systems" is in continuation of one upon
the same subject in the 19th Report, but the investigations at
the ruins at Uuirigua added much to the subject, the results of
which are now given. This account should be of great in-
terest to those investigating the calendar systems and calcu-
lation methods of the ancients. The account of the Hako

religious ceremony is the result of four years of study in
collaboration with an educated Pawnee, and is very complete.
Among other items, the songs forming a feature of the cere-
mony were recorded by graphophone, and the music, tran-
scribed from the cylinders, is here given.

Gas Producers for Power Purposes, by W. A. Tookey
(Percival Marshall), price is., is a small practical handbook
for " purchasers, erectors, and attendants," which should
prove most useful to the many persons who may now be in-
cluded in such a category. Full illustrated descriptions are
given of the various methods of generating " Producer " and
other gases.

Radium, and all about it, by S. R. Bottone (Whittaker and
Co.), price IS. net, is the second and revised edition of a
small book which we reviewed recently. It is satisfactory to
see that so much public interest is taken in the subject.

The Trojan Women of Euripides. — Tran.slated into English
verse by Gilbert Murray, M..A., LL.D. (George Allen), 2S. net.
Copious explanatory notc^ arc added.

Second Stage Magnetism and Electricity. — By R. Wallace
Stewart, D. Sc, Lond. (University Tutorial Press). Second
edition (re-written and enlarged). This little book is primarily
intended for candidates who are preparing for the second
stage examination under the Board of Education, and will bo
found to be a reliable and clear guide for them. Plenty of
illustrations are provided. The index is not as complete as
it might be, as we notice the absence of the words " accunui-
lator," ".secondary battery," "incandescent lamp," "coil,"
&c., which subjects are, however, well described in the book.

BOOKS RECEIVED.

Ambidexterity, by John Jackson. (Kegan Paul.)

Astronomersof To-day, by Hector Macpherson, Jun. (Gall and
Inglis.)

Students' Textbook of Zoology, by Adam Sedgwick.. (Swan,
Sonnenscheiu.)

Unbeaten. Tracks in Japan, by Isabella L. Bird. (Murray.)

The Hawaiian Archipelago, by Isabella L. Bird (Mrs. Bishop).
(Murray.)

Natural History in Zonlnglcal Gardens, by 1". E. Beddard.
(Constable.)

What Do We Know Concerning Ulectriclty ? by A. Zinunern.
(Methuen.)

Modern Theory of Physical I'hcnomena, by Augusto Righi.
(Macmillan.)

The Electro-magnet. C. R. Underbill. (New York: Van
Nostrand.)

Introductory Mathematics, by R. B. Morgan. (Blackie.)

Electro-magnetic Theory of Light, by C. E. Curry, Ph.D.
(MacMiill.ui.)

Divine Dual (iovernment, by W. W. Smyth. (H. Marshall.)

Elemcntar> Microscopy, by F. Shillington Scales. (Baillitre,
Tyndall.)

Moths and Itiitterflics, by Mary C. Dickerson. (Boston:
Ginn.)

Our Stellar I'niverse. Iiy 1. I". Heath. (King, Sell, and
Olding.l

Pattern Making, by J. IC. n.iiigcrficld. (Dawbarn and Ward.)

Preparatory Course of Geometry, by W. P. Workman and A.
C. Cr.Kknell". (Clivc.)

Positive Knowledge, by J. Logan Lobley.

Poisonous Plants, by A. Bernard Smith. (Bristol: J.
Wright. I

The Harvelan Oration, 1904, by Richard Caton, M.D.

Zodiacs and Planispheres, by the Rev. A. B. (Irimaldi. (Gall
and Inglis.)

Annual Report of the Royal Society of St. George.

The Iron and Steel Magazine. (Boston, Mass.)

Petrol Motors Simply Explained, by T. H. Hawley. (Percival
M.-.rsl,.,ll.,i

May, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

113

Photography.

Pure arvd Applied.

By Chapman Jones, F.I.C, F.C.S., &c.

Photographic Photometry. — It may seem to be a very
obvious suggestion and a very simple matter, seeing
that an increase of brightness of the light that impinges
upon a photographic plate, causes an increase in the
darkness of the resulting deposit, to use a photographic
method for the purpose of comparing the brightness or
luminosity, especially of those sources of light that cannot
be brought into the laboratory, such, for example, as the
heavenly bodies. The fact that the increase in darkness
of the deposit is not simply proportional to the increase
in brightness of the light (with equal exposure time) is
easily o\ercome by impressing a light-scale on the plate
so that this shall be subjected to whatever treatment, as
in development, &c., that the other exposed parts receive.
A light-scale is nothing more that a series of small
patches that have been exposed to a uniform light for
different times, generally so that the amount of light
impinging on the respective patches is proportional to
the simple series, 1, 2, 4, 8, 16, &c. By measuring the
opacities of these patches and plotting them against the
amounts of light,-a curve can be drawn that will show
at once the relationship between opacity and light in that
particular case. Since writing this, a suggestion has
actually been published to determine luminosity by esti-
mating by chemical means the metallic silver produced
on a photographic plate by the agency of the lights that
it is desired to compare.

Thus far all is easy, and it is at this stage that the
thoughtless worker too often leaves off, considering that
he has completed his task. It is easy to teach students
to measure and to weigh, nothing of its sort is more
easy, but the difficulty begins with the consideration of
what it is that has been measured or weighed. The
student of chemistry weighs things and gives them
names, but the things he weighs rarely are what he calls
them, and in some cases I have known the material
weighed not to contain a vestige of the substance that it
was supposed to consist of. And so it is in other work,
the whole difficulty is to know what it is that has been
dealt with. In investigational work, there is a strong
temptation to move along the line of least resistance, and
this distinctly is to perfect the methods of measurement.
It is only necessary to get a little knowledge and a good
instrument maker, to reduce the differences between the
results of the repeated measurements of the same thing.
But if the thing measured is not what we take it to be,
if there is, for example, 10 per cent, of uncertainty here,
it is mere deception and waste of time to seek to reduce
the I per cent, of uncertainty in the method of measure-
ment. I am convinced that in a vast number of cases
of very many kinds instrumental perfection is already
far beyond what we can do justice to, and that the
pressing difficulties are the avoidance of loss, and the
more perfect isolation and more truthful recognition of
the thing that is measured.

In the example quoted above in response to the sugges-
tion to use a photographic method for comparing light
intensities, it is not the brightness of the lights that
would be compared, nor is it their activism, nor their
radiant energy. It would be nothing whatever more
than a certain effect that they could produce upon a
certain sensitive surface. If the sensitive surface w-ere
varied the results would be different. The old idea that

activism could be equally well measured by any chemical
change that light can produce, and that the selection of
the sensitive substance is a mere matter of convenience,
cannot, of course, be maintained, and so far as it remains
of use is a testimony to the clumsiness and the want of
discrimination of the methods that we employ.

Brightness is essentially a matter of sight, and the eye
is therefore the only standard instrument for its measure-
ment. By putting over a sensitive plate a coloured
medium so exactly prepared that a continuous spectrum
photographed through it on the plate would give a density
of deposit truly proportional to the brightness of the
spectrum in all its various parts, a combination would
be obtained that would give proportional brightnesses if
used in the manner already described.

Time Development as Afeded by Temperature. — In the
March number I made some remarks on the mechanical
method of development employed by some, in which the
exposed plates are allowed to remain in the developer for
a fixed and predetermined time instead of allowing one's
judgment to decide when the image is sufficiently dense.
I there pointed out what I believe to be the advantages of
such '• time development." In the March number of the
Journal of the Royal Photographic Society is published
a paper by Messrs. Ferguson and Howard, in which they
suggest that plate makers should give with their plates
the times necessary for development at various tempera-
tures with the formula they recommend. For a given
pyro. soda formula, which, by the way, has too little
sodium sulphite to secure a deposit free from the oxidised
products of the pyro., they find that "kodoids " give the
same steepness of gradation at 17" C in 6 minutes, as at
at I7p C in 7 minutes 25 seconds, or at 7'^' C in g minutes
50 seconds. They describe in detail a method of deter-
mining the relationship between time and temperature
when the contrast (or " development factor ") remains
constant.

If makers of plates do this, and photographers, one
and all, do as the makers tell them, then photography
as an art may gain something in the ways I indicated
two months ago, but it will lose an incalculable range of
possibilities in the hands of the skilful. It is one thing
to use mechanical methods when the balance of advan-
tage appears to be in favour of them, but quite another
to seek to supplant all discretion by rigid rules. The case
may be compared to the feeding of convicts who have
their food w.eighed out to them, and the work expected of
them definitely catalogued. There is much advantage
in this exact balancing of work and food ; gluttony and
starvation are avoided and economy is secured. But we
who are not convicts do not weigh our food nor measure
our work, and think that on the whole we have reason
for believing that our health is rather better for the dis-
cretion that we prefer to exercise. We consider that our
experience is worth something.

Iron Lightning Corvdvictors.

Sir Oliver Lodge is reported to have expressed his
opinion in favour of iron lightning conductors in pre-
ference to copper ones. The former allow the current
to flow more gradually and to leak more slowly, while
with copper, especially if it be of large diameter, a more
sudden effect is produced, which may cause side flashes
and do damage. The iron rod may be fused, but only
after it has done its work, and it is easily renewed. A
lightning conductor should be looked upon as a safety
fuse, to be replaced when it has been struck.

KXOWLEUGE .'v: SCIENTIFIC NEWS.

[Mav, 1905.

Conducted by F. Shili.ington Scales, f.r.m.s.

Fibrous Constituents
of Paper.

(Concluded from Page 93.)

Esparto fibres are generally finer and much shorter
than those of straw. They are smooth and cylindrical,
and free from knots. The walls are thick, and the
central canal accordingly very small and uniform.
The ends of the fibres are generally rounded. The
serrated epidermal cells found in straw are also found
in esparto, and can scarcely be distinguished from
these, but the large, thin-walled parenchyma cells are
absent. The esparto leaf, however, bears on its inner
surface a number of little hairs or teeth, some of which
are nearly always found in papers made from esparto,
and which are quite a trustworthy characteristic.

Chemical wf)od-pulp shows flat, ribbon-like fibres,
not unlike cotton, and even at times twisted like the
latter, but with unbroken ends. It would take up too
much space were I to endeavour to discriminate be-
tween the various kinds of wood, such as pine, birch,
poplar, etc., but they all show distinct woody charac-
teristics. The pits in pine wood are quite unmis-
takable, as are the obliquely-placed slit-like pores of
birch and poplar.

Mechanical wood has a strongly-marked woody ap-
pearance, but the fibres are not properlv separated, and
the fragmented nature of the material, due to the way
the fibres have been torn and wrenched across instead
of separated, is quite unmistakable.

It only remains to add that fibres stained with
chlor-zinc iodine are, unfortunately, not permanent.
Permanent preparations can be stained with benzo-
brown with a trace of soda to deepen the colour,
washed slightly, and then stained with benzo-azurin
without soda, and gently warmed, and will form beauti-
ful and instructive mounts, though the differentiation
will not be that of chlor-zinc iodine.

The mounting medium may be water or glycerine and
water, but for permanent mounts glycerine is not con-
venient to use owing to the fact that it will not harden or
dry. To get over this difficulty, glycerine jelly may be
used with advantage, the fibres being first carefully
soaked in water from which the air has been expelled by
previous boiling. Even then there is often much trouble
with minute air bubbles entangled in the fibres. I
have found it quite satisfactory to proceed as follows:
The fibres, whether stained or not, after soaking in
boiled water, are arranged in the centre of the slide,
which is placed upon a brass mounting table. Sufficient
glycerine jelly is then added, and, after melting, the
cover-glass is placed in position and held lightly in place
with the point of a dissecting needle. The glycerine
jelly IS now heated until it just begins to boil, when the
lamp is quickly removed. This disentangles and carries
away from beneath the cover-glass any air bubbles.

After the glycerine jelly has set it should be cleaned up
by dipping the slide in water and wiping it carefully with
a rag, and then the cover-glass is surrounded with two
coats of gold size. Farrant's solution is also useful, as
it is a glycerine mounting medium which hardens at the
edges. Canada Balsam is less suitable than glycerine
media for mounting fibres. They may also be mounted
in water with a little added carbolic acid, enclosed in a
thin cell of gold size.

High-power Microscopy.

Mr. |. W. (iurdon, IMC.M.S., who has contri-
buted several interesting papers on Microscopical
Optics to the Royal Microscopical Society, which
have, however, led to some controversy, recently
gave an address at the Royal Institution, in which
many of his views were summarized in a more
popular way and without the mathematical argu-
ments which are necessary to an adequate discussion of
such a subject. A resume will doubtless interest many of
the readers of "Knowledge iS: Scientiiic News."
Mr. Gordon observed that in the exhibition of a micro-
scopic object under high magnifying power there are
three stages in which difficulties have to be met and sur-
mounted— (i) In the preparation of the object for exhibi-
tion under suitable conditions of illumination ; (2) in the
representation of the object by means of an image ; (3)
in the transmission of the image so found in the instru-
ment to the eye of the observer. Professor Wright
classified the preparation of objects into colour pictures
by means of stains and outline pictures. The method of
staining having manifest limitations, Mr. Gordon pro-
ceeded to refer to the use of cross-lighting or "dark-
ground illumination" in order to show outlines, with
especial reference to Dr. Siedentopf's application of this
principle to the exhibition of so-called " ultra-micro-
scopical particles." In ruby glass, for instance, the
colour is due to minute particles of gold difTused through
the glass, so small as to be beyond the powers of the
microscope as ordinarily used. l!y special methods of
illumination, however, at right angles with the optical
axis of the microscope, and by limiting the plane of such
illumination, the particles come into view as diffraction
discs. Mr. Gordon then dealt with some experiments of
his own, originally suggested by a paper of Lord Ray-
leigh's, but which were still incomplete, which consisted
especially of a method of lif^hting up the object by means
of diffracted light, the principle being explained by a
diffraction slit formed by the edges of two knives stuck
in a board so that their edges overlapped towards the
points, but were about an eighth of an inch a()art near
the handles. It was with such a piece of apparatus thai
Sir Isaac Newton worked when he made his first precise
recorded observations on the subject of difl'racted light.
Mr. Gordon referred to the observation of Ilclmholtz, as
far back as 1H74, that the limit of useful power in a high-
power objective is reached when the lens of the objective
is of such focal length that its diameter is rather less
than the diameter of the pupil of the eye, and that beyond
that point there was no advantage in increasing the
magnifying power of the objective, but that further mag-
nification was best obtained by increasing the power of
the eyepiece. Hut this method had also drawbacks owing
to the smallness of the emergent pencil of light ; such,
for instance, as the greater prominence of dust ujwn the
lens or of (loatinj; particles in the eye. Mr. Gordon con-
sidered that this was responsible for the limitation of
magnifying powers at present in use by microscopists to
ijof) or 2000 diameters, whilst most good work was done

May, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

with magnifications of from 400 to 600 — a statement,
however, which surely needs some qualification, whatever
may be the incidental disadvantages due to high eye-
piecing. However, Mr. Gordon's method of getting over
the difficulty is by the interposition in the tube of the
microscope of a ground-glass screen on which the image
is received from the objective, so as to scatter the inci-
dent rays of light, the screen being made to oscillate in
order to prevent its grain from becoming visible, and so
impairing the details of the picture. This picture can
then be magnified again by means of a second microscope
in place of an ordinary eyepiece, with consequent greatly
increased magnification. It may not perhaps be super-
fluous to remind my readers that the mere magnification
of an object, or even the rendering visible of what could
not otherwise be seen to b^ existent, as under Siedentopf's
experiment, does not give any optical solution as to its
true shape and size. In fact, it has been mathematically
proved, and remains true, to quote Lord Rayleigh's own
words, " In the microscope there is nothing except lack
of light to hinder the visibility of an object however
small. But if its dimensions be much less than half a
wave-length, it can only be seen as a whole, and its parts
cannot be distinctly separated, although in cases near the
border-line some inference may possibly be founded upon
experience of what appearances are presented in various
cases. . . . What has been said about a luminous
point applies equally to a luminous line. If bright enough
it will be visible, however narrow ; but if the real width
be much less than the half wave-length, the apparent
width will be illusory."

Royal Microscopica.1 Society.

March 15th, at 20, Hanover Square, Mr. A. U.
Michael, F.L.S., in the chair. Mr. J. E. Stead delivered
the second part of his lecture on micro-metallurgy, en-
titled " A review of the work done by metallographers,"
illustrated by lantern slides supplied by prominent autho-
rities in several countries. Over 120 slides were shown
on the screen by means of the epidiascope, and were
accompanied by explanations and comments by the lec-
turer. The series commenced with the earliest work of
Dr. Sorby, followed by illustrations of the microscopic
characters of iron and steel, silver, lead, copper, tin, and
antimony. Illustrations were also shown of the changes
produced in metals by strains, a diagram of the apparatus
by which rapid reversals of strains were effected being
exhibited in illustration of this portion of the subject.
The effect of continued heating of an alloy of copper and
tin in boiling mercury and also that produced by immer-
sion in liquid air were demonstrated. Slides were also
shown to illustrate " surface flow " in antimony, and the
microscopic structure of the new silver standard. The
following were elected as Honorary Fellows of the
Society : Prof. Wm. Gilson Farlow, Prof. Herbert S.
Jennings, Prof. Edmund B. Wilson, and Prof. R. W.
Wood.

Notes and Queries.

Bausch and Lamb's New Catalogue.

Messrs. A. E. Staley and Co., of 19, Thavies Inn, Holborn
Circus, E.C., have sent me the new illustrated catalogue and
revised price list of the Bausch and Lamb Optical Company,
of Rochester, New York. The illustrations, most beautifully
reproduced, make the catalogue quite a work of art. I
understand that it will be sent to any applicant on receipt of
three stamps to cover postage.

Miss Frances EHiotl (Staines). — Crystals of lead nitrate would
be best shown by polarized light. Asbestos can be shown by
reflected light with a low power ; geological slides should
generally be thin enough to be shown by transmitted light.
A binocular would exhibit all these very well. I should strongly
recommend you to lose no time in beginning to make your own
slides — until you do this you can scarcely consider yours<!lf as
having started microscopical work, and you will not only find
the work most interesting, but will feel your interest deepened
in many ways. In the meantime dissect as much as you can,
so as to find out for yourself all you possibly can about
the object you are studying, aud read it up at the same time.
It is of the utmost importance to get an interest in some
definite line of study, and to endeavour to master the subject.
Pond life is most fascinating and teaches one many things
both in zoology and botany, and the present is a very good
time to begin. Ready prepared slides have, of course, an
undoubted educational interest, but they are not to be com-
pared in this respect with work done by oneself, especially if
it is the outcome of a definite aim.

Alfred GoUisbnry (Mdxu\-Utozi'n, N.Z.). — It is quite common
to find parasites in insects such as you describe, but the in-
formation you give does not allow me to say more. The ova
also are in quite the usual place. If you want any further
information please send the slides themselves — they will be
duly returned if you wish it.

A. H. Glaister (Darlingloii). — A 1-12 inch immersion of N.A.
f25, such as you possess, will readily resolve Amphlplciira
pelluciiia, and the Watson universal condenser is quite suitable,
but there is no advantage in using the latter in oil contact as
its aperture does not exceed I'o N..\. You say, however, that
your objective is corrected for the short tube, and it must
therefore be used with the short tube only. I think if you
carefully carry out the instructions I gave m " Knowledge "
for November last (page 279), you should has'e no difficulty in
resolving the diatom by means of oblique light, especially
if it is mounted in a medium of so high a refractive
index as realgar. The resolution by means of axial illumina-
tion is less easy ; it is best shown by carefully focussing the
edge of the lamp flame with the condenser and then slightly
racking the condenser up within its focus. Are you sure that
your objective is clean and free from oil on the front lens
behind as well as in front ? Human blood corpuscles may be
classified as follows : Red corpuscles, which appear yellow
when looked at singly, aud white corpuscles. The red cor-
puscles are circular discs, thicker at the sides than in the
centre, about 7'5 ^ wide and i'6 ij. thick (/i = "ooi millimetre)
and without nuclei. The white corpuscles are much less
numerous (about i in 500). They are nucleated and are
classified according to the shape of this nucleus and their
affinity for certain stains, but they vary somewhat. They are
known as leucocytes, and those which take up foreign particles
are phagocyctes. Those which stain with basic dyes such as
methylene blue arc known as basophil, whilst those which
stain with acid dyes such as eosin are termed eosinophil. X
verv general classification of the white corpuscles is poly-
morphous, with lobed, or multipartite nuclei ; lymphocytes,
with large nucleus and little protoplasm ; hyaline, with some-
what, similar nucleus, but more surrounding protoplasm ;
eosinophil, with large granules staining deeply with eosin ; and
basophil, staining with methylene blue.

E. G. W. (Hull). — Many objects, especially botanical
subjects, can be cut quite satisfactorily by hand. The object
is held between the finger and thumb, the index finger being
curved round the tip of the thumb and held horizontally so as
to form a support for the razor. The object may beheld in a
piece of pith or even cork. Inexpensive hand microtomes can
be purchased from any of the instrument makers if necessary,
and in these the object is wedged with pith or cork, or in a
piece of carrot. The knife should be drawn steadily from
heel to toe with a drawing or slicing movement, the cut being
towards one. It should he dipped frequently in water or
spirit and water, and effort should be made to cut thin sections
rather than complete ones. Most objects cut much better if
previously hardened in methylated spirit.

[Communications and inquiries on Microscopical matters arc invited,
and should be addressed to F. Shillington Scahs, "Jersey,"
St. Barnabas Road, Cambridge.]

ii6

KNOWLEDGE & SCIENTIFIC NEWS.

[May, 1905.

The Face of the Sky for May.

By \V. Shackleton, F.R.A.S.

The Son. — On the ist the Sun rises at 4.36, and sets at
7.20 ; on the 31st he rises .at 3.52, and sets at S.3.

Sunspots and faculjE may be observed on the solar
disc on any clear day, whilst spectroscopic observations
usually show conspicuous prominences on the limb. For
locating the positions of spots, &c., with respect to the
Sun's axis, the required data is as follows : —

Date.

Axis inclined from N. 1 Equator N. of
point. j Centre of disc.

May I ..
,, II ..
,, 21 ..
.. 3« ••

24° 18' W. 4° 3'
22" 8' W. 2° 59'
19° 21' \V. 1° 50'
15° 56' W. j 0° 39'

The Moon

—

Date.

Phases.

May 4 ..
.. 12 ••
„ 18 ..
., 26 ..

• New Moon
]) First Quarter
0 Full Moon
d Last Quarter

3
6
9
2

50 p.m.
46 a.m.
36 p.m.
50 a.m.

OccuLTATioNs. — The following occultations of the
brighter stars are visible at Greenwich

Disappearance.

Reappearance

EUi's

Angle from

Name.

e
a

Mean
Time.

Mean

Time.

Ver-

1 point

tex.

point.

tex.

p.m.

pm.

d. )>.

May 6. .

a Taori

!•!

5.28

61"

**^

6.30

287"

246-

2 2

A Leonis ,.

4-6

8.46

124°

It"

9-53

279"

245

8 1

c Leonis ..

5'«

7.a6

n6"

S.M

27i'

2.i8-

9 3

., 15..

38 Virginis . .

6-2

8.30

191°

SCO"

8.48

220=

226'

11 4

.. «5..

k Virginis ..

5-9

11.30

5<^

M°

0.24

329°

:Otf>

II 8

The Planets. — Mercury is a morning star in Aries,
and is at greatest westerly elongation of 25" 26' on the
2ist, when he rises at 3.26 a.m.

\'enus is also a morning star in Aries, rising about
3 a.m. near the middle of the month.

Mars is a conspicuous object in the evening sky, look-
ing S.E. and rather low down. The planet is now at a
favourable point for observation, as he is in opposition to
the Sun on the 8th.

IB90- _ .

0|. position of Maij \'K)b

The present opposition is more favourable than that of
1903, in that we approach nearer the planet by some
9 millions of miles, the apparent diameter of the planet
now being 1 7"- 2, as compared with i4"-6 in 1903. The
position of the planet in the sky, however, is more
unfavourable for these latitudes, since the meridian alti-
tude is 17° lower than at the last opposition. .\s will be
seen from the appended diagram, the present opposition
is not the most favourable since the distance of the planet
from the Earth is 50 millions of miles, whilst under the
best conditions the distance is only 35 million miles.

The latitude of the centre of the planet's disc is + 15°.
Thus the northern hemisphere is presented to us. The
season on Mars corresponds to our .\ugust. On the ist
the planet rises at 8.3 p.m. and on the 31st at 5.15 p.m.

It is interesting to note that the Earth and NIoon as
seen from Mars will appear to transit across the Sun's
disc on May S, since the planet happens to be near the
descending node. The last two transits occurred in 1879
and 1800 at the other node. The next will be in 1984.

According to Mr. Crommelin the diagram below re-
presents the transit of the Earth and Moon as seen from
Mars, across the Solar disc.

The beginning and end of the liarlh's transit across
the Sun's disc will be 4.10 p.m. on the 8th and 0.52 a.m.
on the 9th respecti\ely, hence owing to the absolute
symmetry of the illumination of the planet between these
times, it will be a favourable opportunity for measuring
the diameter and polar compression of Mars.

Jupiter is invisible, being in conjunction with the Sun
on the 4th.

Saturn is a morning star in y\quarius, rising about
2 a.m. near the middle of the inonth.

Uranus is situated in Sagittarius, and rises about
1 1 p.m. on the 15th.

Neptune appears in proximity to the staryaGeminorum,
but it is now getting well to the west, and sets about
1 1 p.m. near the middle of the month.

MiniioRs. — The principal shower during May is the
i\quarids. This may be looked for between May 1-6;
the radiant being in R.A. 22 h. 32 m. Dec. S. 2°., near
the star Aquarii.

KDomledge & SeieDtjf je Nems

A MONTHLY JOURNAL OF SCIENCE.

Conducted by MAJOR B. BADEN-POWELL and E. S. GREW, M.A.

Vol. II. No. 6.

[new series.]

JUNE, 1905.

r Entered at
LStationers' Hall.

SIXPENCE.

CONTENTS.— See Page VII.

Thorp GroLtings a^nd

SmsLll CacmeraLS in

Kclipse Work.

By WiLLi.AM J. S. LocKVER, M.A., Ph.D.

The total solar eclip.se of Augfust next will, no doubt,
attract a large number of people away from these
shores, and possibly the great majority will go armed
with a kodak or some other form of small camera, in
order to bring back a record of the corona.

It is unfortunately generally considered that the work
accomplished with small cameras, that is, those having
an aperture of about one inch, has no scientific value,
because the employment of larger instruments by the
numerous official parties gives all the information that
is desired, and in a more eflicient manner.

During the last few eclipses the small camera has
demonstrated that it is capable of obtaining results
which cannot be secured with instruments of large
dimensions. Perhaps the first most notable instance
of this is the success that was achieved in the photo-
graphy of the coronal streamers. Thus, in the Indian
eclipse of 1898, with lenses of li inches in diameter,
and 9 inches focal length, Mrs. Maunder obtained a
photograph of the corona, showing one streamer ex-
tending to a distance of 12.9 lunar radii from the
moon's limb. At the same eclipse, a blue-jacket made
exposures with the writer's camera (lens aperture 0.8
inches, focal length 8.8 inches) fixed on a stand, and,
with an exposure of 15 seconds, obtained a picture
showing one streamer extending to 10 lunar radii from
the moon's limb.

A reproduction of this photograph is here shown
(Fig. i), but unfortunately the extensions are too
delicate to be satisfactorily indicated.

The special object of the present article is, however,
to draw the attention of those who will employ small
cameras to the use of Thorp's replicas of Rowland
gratings in connection with them. Not only can a pic-
ture of the corona be obtained, but ai the same time, and
on Ihe same plate, the spectrum of the corona is also
secured. This spectrum is in the form of rings, like
that obtained with the prismatic cameras.

It may be said that the spectrum of the corona is
obtained best with apparatus of large dimensions. This
is true if the spectrum of the chromosphere be inferred,
but in the case of the coronal rings, which are faint
(with perhaps the exception of the green ring), there
seems a great chance of small cameras rendering valu-
able assistance.

The main objects then of using these small instru-
ments fitted with these gratings are to give us (a) long
coronal streamers (if there be any), and ifi) a record
of the coronal rings. With this aim it is therefore
best to be well within the shadow-, as near to the central

he bclipse of 1 89S as photographed with a
iches aperture and 8 '8 inches focal length,
seen in the right-hand bottom corner.

line as possible, and to commence the exposures some
seconds after totality has begun, and finish the last
exposure some five or ten seconds before the end ot
totality. This course is suggested to eliminate as fat
as possible the chances of photographing the chromo-
spheric spectum, which might mask the coronal rings.

At the present time Thorp gratings can be procured
in two sizes, the ruled surfaces covering an area of
ij;; by \\ and JJ by J;- inches respectively. The

former are mounted on selected or worked glass 2\ by
2 by is inches in size, while the latter are placed on
glass plates 2 by ij by l-, inches. The prices vary
from fifteen shillings each to ten and even lower.

The grating should be fixed square on to the front
of the camera lens with the lines of the grating in a

ii8

KNOWLEDGE & SCIENTIFIC NEWS.

[June, 1905.

vertical plane. This is accomplished by makings a
small wooden frame, on the insidcs of which grooves
are cut for the insertion of the efratingf. At the bacic

Such an adapter as above described is shown in the
accompanying; illustration. (Fig. 2). This shows ,i
gfrating attached to a 5 by 4 Kodak, and experience

_^ ^fl^^fl^ > jMrTTJIlW^ ^

m5^^^^

^^Ri\ %|5o^^

■

^^^^^^f^'^y^flflr .^^^

■

^' ;^

Plgr. a.— The K"*.\a% attached to a 5 by 4 Kodak Ca

of this frame a circular adapter is fixed so that the
frame can be placed tightly on to the hood of the lens.
It is advisable to make the frame and circular adapter

Fljf. 3. -A rough home* made Camt-r

ilh KratinK attached.

as close fitting as possible, and Id pia. e the grating-
side of the g^lass towards the lens, because the front
lens should be as near to the grating as possible. .A
great advantage of the latter instruction is that the
grating surface is protected from damage.

has pro\ cd tiiat the arrangement serves all practical
purposes.

Those who possess more lenses than cameras can
easily make a box-form of camera, the focussing being
done either by moving' the lens or by mounting the
dark slide in a framework which moves in and out of
the box. The accompanying figure (Fig. 3) illustrates
a home-made camera, which has already done yeoman
service on many occasions.

A camera fitted with a grating- in the way above
described when lurncd directiv towards the sun shows

an image of the sun in the centre of the ground glass,
and a spectrum on each side of this image; these arc
the first order spectra given by the grating-. l'"urther
away from the direct image still, and again on each
side of it, will be found another spectrum, fainter, but

June, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

119

of greater length than the first; these are the second
order spectra.

It may happen that the two spectra of the first order
cannot both be made to fall on the ground glass, be-
cause the plate is not sufficiently large. In this case
no attempt should he made to photograph both spectra,
but the solar image should be moved a little to one
side of the centre, and one of the spectra made to
appear on the plate.

To take fuller advantage of the grating, especially
on such an occasion as an eclipse of the sun, more en-
terprising observers can easily construct a special form
of box camera. By this means both the corona and
the first and second order spectra can be secured.

Such a camera as this is shown in the accompany-
ing illustrations (Figs. 4 and 5), and was used with
successful results in the Spanish eclipse of 1900. Even
the form here given did not take the fullest advantage
ol the grating, because it was arranged only to photo-
graph the direct image of the corona, and the two
orders on one side of this image.

In the figures it will be noticed that the camera is
constructed flat, the lines radiating from the lens
(shown on the top of the box) indicating the directions
of the incident light falling on the photographic plate.
The thicker line on the right (Fig. 5) represents a
diaphragm to cut off the reflections from the side of
the box of the first and second order spectra that were

on the photographic plate and so spoil the result. For

such exposures, therefore, very fast plates should be

Fig, s- The same Camera
above. The white lines in
the Corona and the Spectra.

as illustrated in Fig. 4, but seen from
dicate the directions of the images of

used, and the spectrum plate is one to be recommended.
It is hoped that by employing gratings in this man-

Fig. 6.— The Corona and first order Spectrum as photographed with the Camera shown in Figs. 4 and 5. Enlarged

twice. Exposure 6s seconds.

not required. The focussing of the camera was ac-
complished by making the lens capable of being moved
in and out of the box. It may be remarked that the
grating in front of the lens makes no difference to the
ordinary focal length of the lens, so that cameras which
are tocussed according to distance require simply to
be set for infinity, as if an ordinary landscape was
being- taken.

Fig. 6 will, perhaps, give the reader some idea of
the nature of the picture he will secure, but in this case
only the first order spectrum has been reproduced.
Owing to the fact that the solar light was thrown on
to the grating by means of a siderostat, it was possible
to give a long exposure to the eclipsed sun; for this
example the exposure lasted 65 seconds.

Unfortunately, the plate was begun to be exposed
before the chromosphere was covered by the moon, so
that the spectrum in this instance is chiefly chromo-
spheric. Nevertheless, the green ring forms a very
conspicuous feature in the original negative.

In cases in which the camera is not equatorially
mounted or used in connection with a siderostat, helio-
stat or coelostat, the exposures have to be restricted to
about 20 seconds, otherwise the apparent movement
of the sun would cause the image to change its position

ner a new interest will be given to the user of small
cameras, and that they will be rewarded with results
that may prove of service to the cause of Solar Physics.

The Action of Wood on

Photographic Plates

in the DdLrk.

By C. Ai.N'swoRTH Mitchell, B.A. (O.xon.), F.I.C.

Some years ago Mr. T. C. Hepworth informed the
writer that he had taken away some plates wrapped in
dark paper in a wooden box, and that to his surprise
many of them were " fogged " when unpacked a few
days later. The phenomenon appeared inexplicable
until in 1897 Dr. W. J. Russell showed that turpentine
vapour had a pronounced darkening action upon a
photographic plate, and in 1899 contributed a paper to
the Royal Society in w^hich it was shown that many
other hydro-carbons, such as resins, had th'j same

I20

KNOWLEDGE & SCIENTIFIC NEWS.

[June, 1905.

property. The reduction of the silver was also found
to be effected by vegetable substances with a strong
odour, such as coffee, brandy, and linseed oil, which
contain compounds, terpenes, allied to turpentine.

Dr. Russell attributed the phenomenon to the action
of hydrogen peroxide formed by the oxidation of these
terpenes in the presence of water (see " K.nowledge
.■\.\D Scientific News," this vol., p. 100).

Dr. Sperber, however, held a different theory and
concluded from the results of a simple experiment that
the action of the turpentine was due to photo-chcniically
active radiations. He found that when three plates
were placed horizontally on a skeleton stand under a
bell-jar with the bottom and middle plate film upper-
most and the top plate film downwards, while a dish of
turpentine was placed on the middle plate, all the films
were completely blackened after four days. The ex-
periment was now repeated with the position of the
films reversed, so that the top plate was film upwards
and the other two film downwards. In this case only
the edges of the films were darkened, although the jar
was equally full of turpentine vapour, and there would
thus be the same possibility of chemical reduction. iXc-
cording to the radiation theory, only the edges of the
plates in the second experiment would receive reflected
rays from the wall of the bell-jar, whereas in the first
experiment the rays would strike directly on the upper
film and be reflected directly on to the lower films.

Last year Dr. von .'\ubel showed that various resin-
ous substances could affect a photographic plate
through black paper, but that the property was lost on
heating the substance above its melting point.

Prior to this, experiments had been made by Mr.
Hepworth and the writer to determine whether the
" fogging " phenomenon mentioned above might not
be due to the presence of resinous constituents of the
wood, and it was found that many different kinds of
wood possessed the property of so affecting a photo-
graphic plate in the dark that when developed in the
usual manner a good impression of the section of wood
was obtained.

Later in the year Dr. Russell communicated to the
Royal .Society the results of his very complete experi-
ments on the same lines. He found that the impression
was formed in 30 minutes to 18 hours, and that differ-
ent kinds of wood showed great differences in their
behaviour. Thus conifer woods were particularlv
active, as was also the case with oak, beech, .Spanish
chestnut, sycamore, and rosewood, while elm, ash,
hor.se chestnut, and plane had but little action on Ihu
plate. liut these relatively inactive woods could be
rendered active by exposing them beforehand to sun-
light or to blue rays, and this treatment also rendered
the active woods still more active. Larch gave inter-
esting pictures, the dark rings of the wood being
active and the light rings inactive, while the reverse
was the case with .Scotch fir. The true bark of a tree
and al.so the pith were found to be entirely inactive, but
very old wood and bog wood had retained their activity.

In the present writer's experience very dry wood is
less active than that which has been in :i moist atmo-
sphere. The effect produced by a piece of old very
dry oak is shown in the accompanying figure. The
piece of wood was left for several days on a Barnet
medium plate enclosed in a well-fitting cardboard box
in the dark room. As it had app;ircntlv had no effect,
the experiment was repeated, and the plate developed
after a year.

The print is interesting as showing certain features

not seen in the beautiful pictures obtained by Dr.
Russell. There is a curious halation round the edges
of the wood which seems to indicate that the cross
section of the grain is more active than the longitudinal
section. It also shows that wood that is apparently
inactive may give an impression if left for a very long
period.

Oak left in contact with Photographic Plate- in the darlv for a year.

Herr G. Lunn has recently shown that a straw-
board box is radio-active, the rays apparently proceed-
ing from a number of points over the surface so that
they form an irregular outline of an object placed upon
a photographic plate in the box. The board becomes
spent after an experiment, but recovers spontaneously
if left to itself.

Here, again, it is probable that resinous substances
are the active bodies, but further experiments are re-
t|uired to determine whether hydrogen peroxide is
formed and plays the part of an intermediate agent in
any of these phenomena.

A Bird-like Flying
MoLchine.

By F. W. 11. Ill TciiiNso.v, .M..\., H.Cii. (C.wtah.).

' A Paper read before the Cambridge University Engineering
Society. )

To those who have not given .'ittention to the structure
of a bird's wing, the following rough description may
be of interest. The wing of a bird may be regarded
as having two portions, (i) That part to the outer
side of the wrist joint. The main feathers of this por-
tion arc usually about 10 in number and are known as
the primary feathers. (2) That part to the inner side
of the wrist joint which may be called the body of the
wing. The main feathers of this portion vary accord-
ing to the length of wing.

(a.) A salient characteristic of a bird's wing as a
whole is the comparatively rigid and heavy anterior
edge, and the light, yielding, elastic posterior margin.

June, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

121

(b.) If the primary feathers be examined carefully it
will be seen that each one differs from its fellows, and
that they differ in a graduated series. The quill is
curved, r.nd the feathered portion or penna is set
round this in a helicoidal curve. Here, again, the
portion anterior to the quill is stiff compared to the
portion behind it.

(iT.) Another characteristic of a bird's wing is that
a fore and aft vertical section through the body of the
wing discloses a curve somewhat of this shape.

This curve is more pronounced about mid-way be-
tween the wrist and the shoulder joint, t.e., in the
region of the elbow. When the wing is in the ex-
tended position for flight, this joint is distinctly behind
the front edge of the wing. (Mr. Hargrave, of New
South Wales, has devoted study to this curved por-
tion, and it may, perhaps, be convenient to describe
the curve as the Hargrave curve.)

Mr. E. P. Frost, of West Wratting, a well-known
member of the Council of the Aeronautical Society of
Great Britain, as a result of careful observation of the
structure of natural wings of all kinds, and of the
movements of wings in flight, came to the conclusion
more than 20 years ago that for ordinary flight a wing
is merely beaten up and down.

It is obvious that, owing to the yielding elastic
posterior edge of a bird's wing, on the wing being
beaten downwards both a lift and a drive is obtained.

It is also obvious that on the wing being elevated, a
forward and downward resistance is evoked. (But
the wing is so shaped that the down stroke must en-
counter greater air resistance than the up stroke, apart
from considerations of the amount of energy put into

the up and into the down stroke. Also the arrange-
ment of the wing feathers causes a valvular action.
Air passes through the body of the wing on the up
stroke.)

Mr. Frost has contended that the result of the
arrangement of the primaries must be that on being
struck downward in the air, their ends travel forwards
and upwards. In flight the wing tips of a bird {e.g.,
a rook) can be seen to be curved upwards. If a shed
primary feather be taken and held in its natural
orientation and struck smartly down in the air the tip
can be seen to spring markedly forward. Then the
posterior edge of the penna becomes tense. But when
the feather is not so stressed the posterior edge is
sinuous and has a fullness. Other (normal) movements
have been described, notably the so-called " figure of
eight " curve generated by the movements of the wing
tips; but Mr. Frost has contended that the movements
of the wing tips in what may be considered normal
steady flight are the automatic results of the peculiar
construction of the wing and of its being beaten up and
down against the air.

If during the down stroke the primary feathers are
strained forward and upward within their elastic limits,
it is obvious that energy is stored in them; and its
restoration may in part occur even on the up stroke.

The curve (Fig. A) is taken from Marev's " Le vol
des oiseaux," and the following description extracted
from the text. It was photographically obtained, and
shows the movements of a piece of white paper fixed to
the tip of the first primary of a black crow. The crow-
was caused to fly in front of a dark screen, and the
lens exposed during five beats of the wings. The
curve shows only the trajectory of the white paper;
and Marey directs attention to the increase of distance
between successive loops due to the increasing mean
velocity of the bird.

The recurving at the bottom of the loops would seem

Dirt
Fig. B.

.tion of Flight. <

—Trajectory of Bird's Wing,

KNOWLEDGE A: SCIEXTIEIC NEWS.

[JUNli, 1(,05.

to be due to the restoration of energy from the forward
stressed feather. (The portion which the present
writer ventures to indicate between the lines k and k'
seems to be from just before the commencement of the
down stroke to the commencement of tne next.)

The curve (Fig. B) was recently obtained by Major

B. Baden-l'owell in the loilowing wav : -Small birds
were procured, and tubes of paper were prepared,
whose internal diameters were approximately the
distance between the tips of the outstretched wings of
these birds. The internal surfaces of the tubes were
covered with a coating of lampblack. A tube was
then arranged with one end in a room and the other
end pointing out of doors through an open window,
and a bird liberated within the inner end of the tube.
.\s it P.cw out towards the light a record of the move-
ments of the wing tips was obtained by the tips of the
feathers scratching off the lampblack. Several

observations were made, a fresh tube being used each
time. On page 121 is a reproduction of one of the actual
records (reduced in size).

Major Baden-l'owell considers these marks to repre-
sent the down stroke, and the light scratchings seem to
show that the wing is flexed on the up stroke.

The writer ventures to think that the difference in
the distinctness between the two portions is due to the
wrist being in a slightly flexed condition on the up
stroke in what may be considered the normal position,
and that on the down stroke the stressing of the
primaries automatically increases the distance between
the wing tips and opens the wrist automatically against
its elastic re-action. The wing as a ivholc is essentially
an elastic structure. The absence of recurvation at
the lower portions of the record taken in conjunction
with the form of the down stroke record, would seem
to show that (being in the tube) the bird was not
flapping at full vigour, or quite normally, and that the
stored energy of the primaries was given out during
the latter part of the down stroke.

During flapping flight the primary feathers auto-
matically exert a clawing swimming action.

In reference to the Hargrave curve, Mr. Hargrave
has demonstrated that when air is blown against such
a curved surface — thus

— a lift is obtained against the bight of the curve. He
arranged little trap-doors opening upwards, which

liK. 1.

June, 1905.

KNOWLEDGE & SCIENTIEIC NEWS.

123

opened under the influence of an air current as shown
by the arrow.

This is doubtless due to the formation of eddies by
the air flowing over the rigid lip.

It is obvious that a bird's wing both as a gliding
and a propelling surface is a beautifully efficient instru-
ment.

To test these views, in 1902, Mr. Frost and the
writer, with the co-operation of Mr. C. R. D'Esterre,
arranged the apparatus shown in Fig. i. A pair of
dried natural wings (area about three square feet) were
arranged with a small electric motor and a reduction
gear to flap up and down, the arrangement being

various authorities as that obtaining with birds, and
is not in marked contrast with the ratio obtained (ac-
cording to puljli.shed reports) with the large machine
of Messrs. Wright in U.S.A.

One may describe a flying lift and a hovering lift.

The hovering lift obtained in a confined space, and
only three feet above the floor with the figure i
apparatus with i h.p. gave a lift of 10 lbs.

We considered we had justification for proceeding
with a larger model. This has been constructed and
partly tested and I'igs. j and 3 show it o,i the rough
carriage.

It is intended to run this car on a special trough

Fig. 2.

suspended bv a spring balance from the balanced arm.
The best result was obtained as hereunder : —

slimated

Est

mated loss

No.ol

H.P. (.11
Wings.

m Mo
Trar

or and Gear

Flaps per
minute.

Amps

24 12 10 75% 350 to 400 5 lbs.

The effect was striking. The " bird " flapped itself
round and round, although it fell between the down
strokes. But against this must be set the fact that its
rate of progression was only four or five miles an hour,
no doubt owing to air resistance and friction, which
were considerable, for the apparatus was crude. .'Mso
the "bird" weighed about 21 lbs., which would, of
course, pull it down on tlie up strokes. The oscilla-
tions to .1 iiii.rked extent diminished after the tail was
lilted.

It will be noted that the ratio of h.p. to lift was
I h.p. to 50 lbs. This ratio tallies with that given by

section track, and to arrange in the frame 4 \ertical
guides, one at each corner, of stretched cord or wire.

The machine will be suspended from a spring balance.
The model has certain crudities in the motive portion,
although the workmanship (which, apart from the
wings, was carefully carried out by Messrs. Pyc,
scientific instrument makers, of Cambridge, and the
Cambridge .'\utocar Co., Ltd.) is good. But it is a
testing model only, and is merely intended to obtain
data from.

The wings are of special construction, designed in
accordance with the above enunciated principles. The
total wing area is about 20 times that. of the No. I
model {i.e., about fio square feet). The machine
measures about 20 feet across.

The transmission is by coned friction clutch, and
chains in two stages, to connecting rod. The crank
throw is adjustable for altering the size of angle of

124

KNOWLEDGE & SCIENTIFIC NEWS.

I June, 1905.

flap. The top sprocket of second motion can be raised
or lowered for altering the limiting positions jai the
wings (i.e., the position of the arc). The lower end
of the connecting rod actuates the inner ends of the
levers for wagging the wings by a simple device of two
oscillating roller-carrying links attached to the cross
head, whose pin is constrained by vertical guides.

To the brackets, seen below the wings, are attached
" pectoral cords " of elastic. These store up energy
on the up stroke, and so obviate too violent alternations
of load on the driving mechanism.

The motor is a nominal 3 to 3^ h.p. petrol cycle-
engine.

The wings are at present arranged to flap 100 times
a minute, which is, of course, considerably less than

powerful sweep of the wings. The spring balance
reading is here obviously fallacious so far as register-
ing the lift goes, because the rope is pulling the machine
back. However, at the rough tests so far made, the
balance shows a diminution of reading of 80 and 160
lbs. at the down stroke when the machine springs up-
wards but also forwards.

.\t the preliminary trial already made the wings de-
scribed a diminished angle to that of the No. i model.

It should be noted that with this angle and 100 flaps
per minute the wings appear capable of evoking a
resistance of about 100 lbs. each, and the machine is
raised about two feet at each stroke. It is difficult at
present to form a correct idea of the position of centre
of pressure, but we think that it goes through an arc of

Fig- 3

proportionately corresponding to the increased area
and h.p. But increased area does not imply propor-
tionajly increased resistance.

The machine has been suspended from a tree bough,
and the wings flapped under power. The results are
very promising. .At each down stroke the whole
machine, apart from the carriage, weighing 232 lbs.,
is lifted up bfjdily into the air and forwards. It rises
about two feet each stroke. It looks just like a gigan-
tic bird trying to fly under similar conditions. At the
down strokes the suspending rope leaves the vertical
and becomes markedly inclined. The pull on the rope
then pulls the machine back, so that even if it be
capable of flight it cannot fly under these conditions.
At the down stroke it seems that, if the rope were then
severed, the machine would travel up and away with the

2.25 feet on the down stroke.

In the model, which is susceptible of considerable
lightening, we have nearly 33 square inches per lb.

There arc grounds for believing that a feathered wing
made of a number of units can exert a greater resist-
ance than a simple wing; such as that of the insect or
bat type, or the various simple mechanical wings which
have been hitherto used in wing flapping machines.
There are experimental grounds for believing that re-
sistance is more dependent on periphery of an aeroplane
than on its superficial extent.

Furthermore, the primary feathers must certainly
act as a series of stepped aeroplanes, each acting on
air from a different level which has no/ had a downward
velocity imparted to it by having had to sustain the
weight of a previously acting supporting surface.

June, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

TKe Nature of Life.

By Geoffrey Martin, B.Sc. (Lond.)

[This interesting paper, by Mr. Martin, opens up some new
conceptions regarding the nature and origin of life.

In the first part the author commences by explaining how
all chemical compounds decompose at a certain critical tem-
perature and pressure, and how the number and kind of atoms
m the molecule decide the degree of temperature. He then
discusses what would be the composition and properties of a
substance whose critical temperature and pressure coincide
with those now prevailing on the earth's surface, and becomes
to the conclusion that living protoplasm possesses in every re-
spect the properties of such a compound. He then develops
this idea. Some parts of the protoplasm decompose some-
what more rapidly than other parts, and, corresponding more
sensitively to certain influences, thus develop into different
organs.

In the second part (to be published next month), it is suggested
that since the temperature of the world's surface wasiu tormer
times very difi'erent to that which now prevails, the modern
protoplasm is simply the product of evolution of older kinds
of protoplasm, living at high temperatures, in which heavier
elements, such as silicon, phosphorus, sulphur, &c., replaced the
lighter elements which now principally compose it.

In a third part, future developments are discussed. — Ed.]

If we place a given chemical compound (say CaC03)
in a closed cylinder and subject it to a continually in-
creasing temperature, keeping the pressure constant
by means of the piston, then at a certain temperature
range the compound begins to decompose. If, now,
we increase the pressure sufficiently, the decomposition
ceases and the substance can now bear a higher tem-
perature than before without decomposing. Proceed-
ing in this way, it is obvious from the finite nature of
the mass of the atoms, and from the limited intensity
of the forces holding them together in the molecule,
that ultimately at some definite temperature the ex-
ternal forces tending to drive the atoms apart will
become equal to the maximum internal forces that the
atoms can exert on each other in the molecule. It is,
therefore, obvious that above a certain definite tem-
perature, depending upon the nature of the molecule,
no pressure, however great, can -prevent the substance jrom
completely decomposing. This temperature and pressure,
above which a compound is incapable of existing, we
will call the critical temperature and pressure of decom-
position of the compound.

The critical temperature of decomposition v.ould,
therefore, be completely analogous to the critical tem-
perature of liquefaction of a compound — only in the
latter case we are dealing with the temperature whereat
a certain molecular condition of existence disappears;
and in the former case with the temperature whereat
a certain atomic condition of existence disappears.

Since atoms are a very much more finely divided
form of matter than molecules, it is clear that the criti-
cal temperature of decomposition of a compound must
be a very much sharper and clear-cut constant than its
critical temperature of liquefaction.

The critical temperature and pressure of decomposi-
tion of even very unstable compounds is usually very
high. For example, although AUCI3 is almost com-
pletely decomposed at about 200°, yet Rose's experi-
ments show* that it is capable of existing in traces at
very high temperatures indeed. Cyanogen, ozone, and
• /■). Chem. Soc. (1895) 67. 8S1.

the oxides of nitrogen, although very unstable at
ordinary temperatures, seem capable of existing at ex-
cessively hign temperatures.

In general, the smaller the number of atoms in the
molecule of a compound, the higher is its critical tem-
perature of decomposition; whereas the greater the
number of atoms, the lower the critical temperature.
1 he reason of this is, of course, due to the general fact
that the more atoms there are added on to a molecule,
the feebler is the intensity of the forces holding the
atoms together in the molecule — as is evident from the
general observation that the more complex a compound
is, the more easily decomposable it is.

If, now, by some means or other we proceed to
steadily add on atoms to a molecule so as to make it
more and more complex, we steadily lower its critical
temperature of decomposition. And by adding on a
suitable number and kind of atoms, we could reduce
the critical temperature and pressure of the compound
until they coincided with the normal temperatures and
pressures ivhich hold upon the earth's surface.

Such a compound would be possessed of an extra-
ordinary sensitiveness to external influences on ac-
count of the sharpness of the constants called above
the critical temperature and pressure of the compound.
A slight increase of temperature, or a slight decrease of
pressure, would serve to throw it into a condition of
rapid chemical decomposition; whereas a slight in-
crease of pressure and decrease of temperature would
cause the substance to suddenly cease to decompose;
and even did we maintain the external temperature and
pressure exactly at the critical temperature and pressure
of the compound, nevertheless, the external impulses
which are continuously pervading all space in the
neighbourhood of the solar system, beating inter-
mittently upon the sensitive substance, would alone
be sufficient to throw it into a series of rapidly
alternating states of decomposition and repose.

In order to generate such a complex compound, we
must first take as the central atom an atom capable of
exerting a high grade of valence, and possessing a
well-developed power of self-combination. The high
valency grade of the central atom is necessary in order
that we may be able to add on to it atoms of different
natures so as to regulate precisely the stability of the
resulting compound; and the power of self-combination
is advisable in order that the molecule may be of the-
necessary grade of complexity, so as to reduce its
critical temperature and pressure of decomposition
exactly to the temperature and pressure which hold
upon the earth's surface. The atoms added on to the
central atom must possess a small but perceptible
affinity for the atom and for themselves.

What known elements, therefore, would be most
suitable to enter into the structure of such a compound?
A study of the elements will convince the reader that
the element of high valency grade which possesses the
power of self-combination (and, therefore, the possi-
bility of generating complex compounds) most highly
developed is carbon; and the five elements most
abundant upon the earth, which possess a small but
quite definite mutual affinity for carbon and for them-
selves, are hydrogen, oxygen, and nitrogen, and in a
lesser degree sulphur and phosphorus.

We should expect, therefore, to find such a complex
compound to be composed chiefly out of carbon,
hydrogen, oxygen, nitrogen, and containing small
amounts of sulphur and phosphorus. Our conclusion
is confirmed when we come to survey the nature of the

KNOWLEDGE & SCIEXTIEIC NEWS.

I June, 1905.

complex compounds containing carbon, hydrogen,
oxygen, and nitrogen — namely, the proteids. We find
that thev are almost invariably characterised by their
feeble stability, and have undoubtedly a comparatively
low critical temperature of decomposition. So feeble,
indeed, is the general affinity of carbon for hydrogen,
oxygen, and nitrogen, that at a red heat the whole of
organic chemistry is destroyed.

From the facts discussed in my work, " Researches
on the Affinities of the Elements," chap. II., pp. 120-
123, it is probable that such a compound would have
definite physical characters. For since its atoms at-
tract each other but feebly, the molecules would also
attract each other but feebly. It would, therefore, be
either of a fl.iid or semi-fluid nature, and soft. Be-
cause its molecules are very great it would not be
volatile. Does such a compound exist? I believe so,
the compound being nothing more nor less than the
protoplasm v.hich forms the basis of living matter.
All its chemical and physical characteristics agree with
what we should have expected. It is formed out of the
four elements, carbon, hydrogen, oxygen, and nitrogen,
with small amounts of phosphorus and sulphur; it is of
a semi-fluid and soft nature; it is in a state of continual
and intermittent change so long as life continues; the
temperature of living matter keeps remarkably con-
stant, precisely as it should do on our supposition — a
temperature too high exceeding its critical temperature
of decomposition and thus destroying its structure,
while a temperature too low causes it to cease to de-
compose and the living matter becomes inactive.

The temperalure range of animal life, then, is probably
nothing mere nor less than the range of the critical tem-
peratures cf decomposition of a certain series of very
complex carbon compounds grouped together under the
name ' ' protoplasm. ' ' The external pressure of the
atmosphere coincides roughly with the critical pressures of
decomposition.

The incessant varying in the external conditions of
temperature and pressure, and the external influences,
such as radiation and light, which are continually beat-
ing upon the earth from external space, are thus the
cause of the continuous change characteristic of living
matter. In fact, just as a tuning fork is set into motion
by vibrations of a certain definite frequency, and by no
others, so living matter is so constructed as to respond
continuously to the incessant minute fluctuations in
the external conditions which hold upon the earth, the
state of response being what is known as life.

The difference in the functioning of the different parts
of the protoplasm (which exhibits itself in the tendency
to produce different organs) is probably due to the
different sensitiveness of the different sorts of proto-
plasm to different specific external influences. .Such a
differentiation in the nature of the protoplasm in the
different organs is probably brought about by the sub-
stitution of minute quantities of light or heavy elements
for the other elements in its structure. Such a sub-
stitution alters to a slight extent the critical tempera-
ture of decomposition of the protoplasm, and thus
makes it more or less sensitive to certain specific ex-
ternal influences according to specific needs. This
probably explains why certain specific heavy elements
are retained in considerable quantities in certain organs,
and are almost entirely absent from other organs. The
different modes of action of the protoplasm are thus
probably due solely to the different critical temperatures
and pressures of certain parts of the protoplasm.
(7'o he continuid )

The ConservsLtion of

MSlSS.

By Alfred W. Porter, B.Sc.

Fellow of, and Assistant Professor of Physics in, University

College, London.

{Continued from December, 1 904.)
IL

Ls the first part emphasis was placed on the fact that an
ordinary balance compares two forces witli one another —
viz., the u'ciglits of two bodies — and that the weight of a
body is not a satisfactory measure of the amount of stufT
in it, because the weight varies from place to place. We
further defined another quantity — the mass of the body —
which was asserted to be a constant for the same body
under all conditions. It is our intention now to show
that a relation exists between these quantities. For, in
fact, the weight of a body is only another term for the
action between the body and the earth. These are two
bodies which change each other's motion by their mutual
influence. The motion of the earth produced by a falling
stone is, indeed, too small to be directly observed; and,
moreover, as we are on the earth, and move with it, it
would in any case be liable to escape our observation.
ISut we nevertheless do not doubt that this case falls in
with the general rule that every action is accompanied
by an equal but opposite reaction.

If we take this for granted, we may write clown an
equation for the earth and stone similar to that between
the inter-acting billiard balls : —

Mass of stone increase in velocity of earth.
Mass of earth ~ decrease in velocity ot stone.

The time during which the change is observed may be
any whatever ; but it will be most convenient to refer to
the changes in velocity that take place in unit time —
that is, to the rate of increase, which is called the accelera-
tion. Denoting the masses of stone and earth by the
letters m and E, and the accelerations by a and g, the
equation becomes

m a

'^ ^ " S
which may be written

ing = — E(j.

It is this product which measures the action between
the two bodies ; nig is the action of the earth on the
stone — i.e., its u'eight — whereas — Ma is the opposite and
equal reaction of the stone on the earth. The connection
betweenjwi^/i/and niassis that the former is the latter mul-
tiplied by g (the acceleration while falling freely). Now
all experiment goes to show that when disturbing causes
are eliminated, all bodies have the same acceleration in
the same locality ; so that with this restriction as to
locality, weight and mass are proportional to one
another. On the other hand, the relation between the
two is difTerent even for the same body when the locality
is changed. For the sake of clearness think of one body
alone. In any particular locality it has a certain weight,
a certain mass, and a definite acceleration under the
action of the earth's pull. In another locality it con-
ceivably has a different weight, mass, and acceleration.
In each locality these three quantities are not indepen-
dent of one another, but are related by the etjuation —
Weight = mass x g.

And the important question to which an answer must
be given is — Can we account for the variation in weight
by the variation in g alone, without supposing the mass
to vary, or is the mass also subject to variation ?

June, 1905.]

KiNOWLEDGE & f SCIENTIFIC NEWS.

127

Or again, we take the same substance in a definite
locality, but in more tlian one chemical state, e.g., iodine
and silver, at first uncombined and then in the state of
combination. The questions to be asked are : Is the
weight conserved during the reaction ? Is the mass con-
served ? Is the acceleration g conserved ?

The question to which most attention has been given,
though not always with a clear perception of the issues,
IS, Does chemical change influence weight ?

It is easy to produce a chemical transformation in a
closed vessel, and tolerably easy to test on a balance the
weight of the contents both before and after the action.
Measures were made to this end in 1893 by Landolt on
(amongst other things) the combination of silver with
iodine, but with uncertain result. Later investigations
made by him (in 1900) on the transformation of a ferrous
into a ferric salt, in which the clearest evidence of
apparent weight was obtained, are unfortunately com-
plicated by the fact that there is here a change also in
the magnetic properties. A piece of iron placed in a
magnetic field becomes magnetised, and tends to move
in it unless the field is quite uniform. Any variation of
its magnetism due to a change of its magnetic perme-
ability would entail a corresponding change in the pull
from magnetic causes ; and this action might conceivably
be the cause of the apparent change in weight. Besides,
there might be a more direct connection between mag-
netism and gravity, so that change in one necessarily
provoked a [change in the other, whether the magnetic
field were uniform or not. It is interesting to be re-
minded that Faraday in 1850 had sought for a connec-
tion between electro-magnetism and gravity. He had a
" long and constant persuasion that all the forces of
Nature are mutually dependent " and although his
experiments led to a negative conclusion, yet the results
did not shake his " strong feeling of a relation between
gravity and electricity, though they give no proof that
such a relation exists." Leaving aside some unsatis-
factory experiments of Sanford and Ray in America this
was the state of affairs in 1901 when Heydweiller, of
Breslau, published in "Drude's Annalen " the results of a
series of experiments. These were made with every pre-
caution, employing a variety of reactions ; and in every
case but two a diminution of weight was found to have
occurred during the chemical change. The total weight
of reacting substance varied from 160 to 280 grammes, and
the alteration in weight amounted in one case to more
than one-fifth of a gramme. Excluding all those cases in
which the observed change did not exceed, or barely
exceeded, the expected errors inevitable to the experi-
ments, Heydweiller considers that an alteration of weight
has been safely established as taking place [a) when iron
reacts on alkaline or acid (but not neutral) copper sul-
phate solution, ih) during the solution of acidified copper
sulphate in water, and [c) during the action of caustic
potash on copper sulphate. No conclusion could be
arrived at as to the dependence of the change upon the
amount of action taking place. Nor does there seem to
be any obvious reason why alkaline and acid solutions
should exhibit a different behaviour from a neutral
one if the change in apparent weight is in reality due to
an alteration in gravitational pull. It should be observed
that the reactions employed are only mild ones. The
impossibility of employing more vigorous ones arises from
the necessity of preventing any action from taking place
until after the first weighing. The transformation took
place in an inverted U-tube, each limb at first containing
one of the substances that were afterwards to be mixed.
And, indeed, Lord Rayleigh has pointed out that a pos-
sible source of error in the experiments is that, even with

the materials actually used, some change may have been
progressing during the first weighing. If, for example,
copper sulphate is in one limb and water in the other,
there will not be complete equilibrium; water will distil
over to the salt, and although this motion will not directly
modify the pull on the balance, since the forces called into
play are internal forces, yet thermal change will accom-
pany the evaporation and condensation of the water (the
hmb containing the water will cool and the other will
rise in temperature), and the difference of temperature
thereby set up will interfere with the accuracy of weigh-
ing owing to the con\ection currents that it will produce.
It must be remembered that the effect observed is only
small, and although every endeavour was made to ex-
clude possible sources of error, it must be admitted that
the results form a very precarious foundation for theory.
The evidence would be strengthened if there were some
degree of regularity in the amount of the change ; but no
regularity exists apart from the fact that the change is
negative in all the cases in which it is greater than the
expected error. The magnitude of the change observed
is well within the powers of a good balance to demon-
strate ; there is therefore every reason to hope that by
the accumulation of evidence all doubt will eventually be
removed.

It would be of great theoretic importance to learn that
some change does really occur. At present, gravitation
is somewhat of a stumbling-block from the point of view
of theory. It is so indifferent to circumstances. How is
it that the earth pulls a body with sensibly the same force
whether a plank (say) is interposed or not ? What is the
nature of this tie between the two bodies which is not
severed thereby ? It is true that by inserting a
plate of a magnetically indifferent body like copper
between two magnets the attraction (or repulsion)
between them is not modified. But in what sense can
we regard a plank as being gravitationally indifferent ?
Again, it has recently been shown by Poynting that the
pull on a crystal such as quartz, which is a substance that
in most respects exhibits different physical properties in
different directions, does not sensibly depend upon the
orientation of it with respect to the earth. Whether it
will turn out or not that the ether is the medium con-
cerned with the transmission of gravity, it is clear that
the propagation takes place in practical independence of
the structure of the matter through which it passes.
From the general physical behaviour of bodies, therefore,
it is not to be expected that any modification should be
brought about by chemical change which, as far as we
know, simply consists in a re-arrangement of the finer
parts of which a substance is composed. Any modifica-
tion, then, which may eventually be demonstrated to take
place will introduce a new element into the theoretic
consideration of gravity. It will indicate that, from the
point of view of this question, the nature of the changes
which are dealt with in chemistry are of an essentially
different type from the coarser changes which are termed
physical. Mixing two substances together may not
change their weight, and, in view of Poynting's experi-
ment, we do not expect that it will ; but bring about the
more intimate chemical union, and the grip of the earth
on the body may have changed. The knowledge gained
by the final settlement of this question will affect not
only gravitational theory, but will have to be taken
account of also in the consideration of the exact nature of
the forces which come into play in chemical change.
On the other hand, if it should turn out that the varia-
tions found by Heydweiller are due to unsuspected sources
of error, there will be no fact known connecting gravita-
tion with any other physical property of matter.

128

KNOWLEDGE & SCIENTIFIC NEWS.

[June, 1905.

Although the question of the alteration in weight is not
yet settled, it is not premature to consider what is in-
volved in the acceptance of it. We have seen that it is
bound up with other questions. Its acceptance involves
that there shall also be a change in the mass of the body
or in its free acceleration under gravity, or in both. Not
long ago a possibility of the change in the mass of a
body would not have been considered even except with
great reluctance. The constancy of mass has been one
of the fundamental tenets of the creators of the present
state of physical science. Physicists of the Xineteentii
Century would have turned with preference to the alter-
native possibility. We shall consider these points in the
next part in connection with the electrical origin of mas-.

{To be continued.)

-j.^^.^^^

Star MqlP.— No. 2

Pegasus. AndromedaL, and Pisces.

.\s regards the general configuration of stars, the chiel
feature included in the present map is the " Square of
Pegasus " (although, be it remembered, one of the stars
is not in I'egasus). This will Le easily recognised near
the centre ot the map, and in the actual heavens is a
ready means of determining the true North. At the top ol
the map is the greater portion of Cassiopeia, which con-
stellation is included complete in Map 1.

One of the most remarkable objects within this region
is the Great Nebula in Andromeda (R. A. oh. 3«m. Dec.
40' 45' N.), one of the itw visible to the naked eye.
This was tlie first nebula noted, having been described
long before telescopes were invented. It is of elliptical
shape, and when viewed in a powerful telescope it seems
to consist 01 a numb.r of rings with bright centre, pre-
senting an appearance somewhat similar to a hazy view
of Satarn. The spectrum of this nebula is continuous,
and would therefore be that derived from a large number
of stars of different compositions. Hence it has been
inferred that this object may ba in reality a vast group of
very distant stars, and not a gaseous neDula. hi i«S5 a
«' Nova " burst forth in this nel)ula.

7 Andrcmeda (I. h. 5tm. + 4i''5i') is a fine triple star.
Two stars, magnitude 2i yellow, and 5J blue green, are
at a distance of io"-2, and the latter seen in a powerful
telescope resolves itself into a binary at a distance of
o"-45. Near this another peculiar nebula of very
elongated form occurs.

o, T), and ' Cassiopeia, as well as 5 Cephci, are double stars,
the first and last named being also ■ ariables which have
already been referred to in the description of Map I.

7 Arietis (I. h. 48m. + iS'49') is one of the earliest dis-
covered double stars, magnitude 4 2 and 4-4, distance 8"-3.
I Triangiili (II. h. 7m. + 29' 50') is a double star, one
5th magnitude yellow, the other 7th magnitude blue.
Distance 3"-5.

tiCygm iXXI.h. 40m. + 2a'^i8') is a double star, of4th
and 5th magnitudes. Distance 2"-6

^Aqiiarii [XXll. h. 24m. — o" 32';, double star, both of
4th magnitude. Distance 3"'i.

(Star Map No. 1 (North Polar Regions) appeared in
the May number.)

The Nation's Latest
Acquisition.

By W. P. PvcK.\ir, A.L.ti., F.Z.S., &c.
" There are no examples of Dtplodocus at present in
the collection." Such is the statement to be found in
the Guide to the Geological Galleries of the British
Museum. To-day, thanks to the generosity of Mr.
Carnegie, this gap has been filled by the splendid gift
of a replica of the magnificent specimen of this enor-
mous creature in the Carnegie Museum at Pittsburg.
Since the Dinosaurs hold so important a place among
the reptiles, a short account of the remarkable speci-
men just added to our National Natural History
treasure-house may be of interest to many readers of

" K.NOW LEDGE."

Diplodocus Carnegii, as this specimen has been named,
represents one of the largest land animals known,
measuring some eighty-lour feel from lip of snout to
tip of tail, and between thirteen and fourteen feet high
at the top of the haunches. Of this enormous length,
over fifty feet belong to the tail, and about twenty to
the neck. .Apart from its great length, the vertebral
column is remarkable in several particulars. The neck
\ertebra', liftecn in number, recall those of birds, in
their great pneumaticity, as well as in the shape and
disposition of the cervical ribs. The neural spines of
Ine thorauic \ertebra; are of great height, as one would
expect from the great length of the neck. But the
caiidals, perhaps, are the most interesting. These
taper rapidly, terminating eventually in a number of
long cylindrical \ertcbra; forming a whip-like
termination to this appendage. W'hether this
peculiarity is the result of degeneration, or
whether of specialization to some peculiar function,
is not known, but the former is probably the case. At
the place where the tail first rests upon the ground two
separate sets of two vertebrae each are found to be
firmly fused together. Prof. Osborn suggests that
this fusion is the result of mechani-
Jcal strain brought aljout by the use
<>f the tail to form a tripod, inas-
(much as this beast, he believes, was
jin the habit of rearing itself upon
',its hind legs, after the fashion of a
kangar(K). .\n cxamiii:ition of these
vertebral, however, rather
C<vv.>y seems to show that this
' fusion is the result of injury.
The whole aspect of the
:;:ii:ral seems to contradict the
possibility of any such acrobatic
feats as standing erect.

The pillar-shaped legs terminated
in five short, stout toes, of which
the three innermost on each foot
bore large claws, which, it is
significant to note, are twisted out-
wardly. The outermost digits
were clawless.

The skull, which was about twf)

feet in length, is curiously flattened,

presents a rniinded muzzle, and an

extraordinarily small brain cavity;

so small, that the brain has been

Kig... section 01 upper described as scarcely larger than a

ol Diplodocus to large walnut ! Teeth were con-

oi 'the t«iT"'°" fined to the fore part of the jaws,

aCPPLZMKNT TO " KNOWIEDQK & SOIENTIFIO NEWS," Jimt, 1906.

MAP No. 2.

MAP I

("I^ortK. Pola.7- ^^S'or,

MAP No. 2.
Pegasus, Andromeda, and Pisces.

June, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

129

and were long and peg-like; as worn out they were
replaced in constant succession. The manner of this
replacement is indicated in Fig. i, which shows a sec-
tion through the upper jaw.

It has been suggested that this monster was largeb'
aquatic in its habits, partly on account of its enormous
bulk, and partly because of the position of the nostrils.
These opened, not at the end of the snout, but in the
form of a large hole between the eyes — the white shield
in the front of the skull in the photograph. There can
be little room for doubt, indeed, but that the peculiar
position of these apertures represents an adaptation to
an aquatic habitat. Probably Diplodocus, like the
modern hippopotamus, passed most of its time sub-
merged in rivers, and thrust the head out of the water

ing. It seems more probable that the Dinosaurs were
viviparous.

A more plausible hypothesis as to the causes
of extinction of Dinosaurs, and other animals which
have attained huge proportions, is that of Dr. C. W.
Andrews. " An almost necessary corollary," he re-
marks, " of this increase in bulk, is . . . the lengthening
of the time taken to attain sexual maturity .... A
necessary consequence of the longer individual life
will be that in a given period fewer generations will
succeed one another, and the rate of evolution of the
stock will, therefore, be lowered in the same propor-
tion. If, now, the conditions of life undergo change,
the question whether a given group of animals will sur-
vive or become extinct, will depend upon whether it

Replica of Diplodocus, (Fmm the l

at intervals, just far enough to enable breathing to take
place. Here it lived upon succulent vegetation, which
was torn up by the rake-like teeth.

The causes which led to the extinction of this
monster, and of others of like kind, will always remain
a mystery. These leviathans represent the high-
water mark attained by the reptiles, and it is
significant to note that they disappeared just as
the mammals were entering the arena of life. The
late Prof. Cope, indeed, suggested that these early
mammals (Jurassic) played no small part in the over-
throw of their giant neighbours; that beasts of the size
of the shrew and hedgehog hunted out the nests of
these colossal creatures and gnawing through the shells
of the eggs, destroyed the young. This explanation
savours rather of wild conjecture than scientific reason<-

giiialin tilt: Cai-negie Miiicum at i'l/tshuii;.}

can undergo sufficiently rapid variation to enable it to
avoid getting so far out of harmony with its surround-
ings that further existence becomes impossible. ..."
Finally, it may be well to remind our readers that
the great American continent has by no means the
monopoly of these titanic Dinosaurian beasts. In the
British Aluseum, for example, there may be seen the
limbs of an enormous Dinosaur known as Cetiosaurius,
obtained some years ago in Oxford. This creature
must have rivalled Diplodocus in size. The Great
Iguanodon, again, which once roamed over our islands,
might well have disputed the right of way with Diplo-
docus, inasmuch as it stood some i8 feet high, and had
the fore limbs armed with powerful spurs. But of
these, and others, we may have more to say on another
occasion.

I30

KNOWLEDGE & SCIENTIFIC NEWS.

(June, 1905.

R©Lre Living AnimoLls
in London.

By P. L. ScLATKR, Dk.Sc., F.K.S.

v.— Scoresby's Gull iLeucophaus scoreshii).
This uell-markcd species of gull was first described
in 1823 by the late Dr. T. S. Trail in a paper read
before the W'ernerian Society of Natural History, and
subsequently published in the fourth volume of that
Society's " Proceedings." It was named by Trail
after Scoresby, the " celebrated Navigator of Icy
Seas," and the description was based on a specimen,
then in til ■ Miisriini of tin- Rovnl Iiistiliitidn at IJver-

-hl

" frequently laying its two eggs in the communities
of the large Dominican (iull, Lanis tfoniiiiicanus, but it
also has separate breeding-places." Kggs received
from Capt. Abbott are in the collection of the Britisii
Museum.

More recent intellii^ence respecting -Scoresby's Ciiill
in the I-"alkland Islands has lately been procured by
Mr. Rupert \"allentin, who informs us* that this bird,
locally called " The Dolphin," is fairly common in the
neighbourhood of Stanley, Port Louis, and Roy Cove,
but that none were seen after the end of I-'ebruary.
At Stanley and Port .\rthur both adult and young speci-
mens were always to be met with near the slaughter-
houses in quest of offal in the months of November and
December. .\t Rov Co\e Mr. ^'allentin frequently
ohsrrwd tlu-ni walkin- '>n llir nM:itliis^ ln-ds u( kelp

v.— Scoresby's QuII.

Ill that |)iirt engaged in the whale-tishery at the .South
.Shetland Islands. .Sctjresby's gull is, in fact, ex-
clusively an inhabitant of the .Antarctic seas, and does
not occur in the North Polar region, where the naviga-
tor after whom it is named made so many discoveries.
X'igors had, no doubt, overlooked Trail's description,
or he would not have renamed this bird in 1H2S, when
it was called by him Imtiis lutmalorlyiutits frf>m its bright
red bill, and was subsequently figured under the same
name by Jardine and Selby in their " Illustrations of

(I ihillKT l)V

and feeding on the crustaceans at
the decaying seaweeds.

By recent authorities Scoresby's Gull lia.> been
separated from the more typical forms under the
generic title Lcucpplniui. Mr. Howard Saunders, our
principal authority on this group of birds, points out
that it has " a remarkably short, stout crimson bill,
coarse feet with somewhat excised webs, and a decided
hood in the immature stage, which wears off as the
bird attains adult plumage." These characters were

Ornithology." Vigors' specimens were procured by I fully shown in the two specimens of this rem:irkabie

Capt. King at Port Famine in Patagonia, during the
voyage of the Beagle, and nearly all the subsequent
explorers of the coasts of the NIagellan-Slraits and
Cape Horn appear to have met with this gull, which
seems to be by no means uncommon in far southern
latitudes.

This gull also inhabits the Falkland Islands, and, as
recorded by Capt. Abbott, breeds there in December,

species which reached the Zoological .Society's Cardcns
in October, 1903. One of these died in l-'ebruary,
1904, the other, which is still living, is the original of
the accompanying drawing by Mr. Goodchild. .So far
as I know these are the only specimens of this bird tli.it
have ever been brought alive to Europe.

' " MttiuhisUr Mtmoirs," Vol. XLVIll. (1904), No. 2j.

June, 1905]

KNOWLEDGE & SCIENTIFIC NEWS.

131

ASTRONOMICAL.

By Charles P. Butler, A.R.C Sc. (Lond.), F.R.P.S.
Tenth Satellite of Sa-txirn.

Another interestiiif^ communication from the Harvard
College Obser%-atory announces ttie discovery by Professor
W. H. Pickering of a new satellite to the planet Saturn, bring-
ing the number of its attendants up to ten. The period of
revolution of the new satellite is stated to be 21 days, which is
very nearly equal to that of the seventh satellite Hyperion.
The body is evidently extremely faint, as it is estimated to be
three magnitudes fainter than Hyperion (which is about 17),
so that it is doubtful if the new object will be detected visually
for some time. The orbital motion is believed to be direct.

* * *

Seasonal Changes on Mars.

A telegraphic communication from Cambridge, U.S.A.,
announces that Mr. Percival Lowell, at the Flagstaff Obser-
vatory, Arizona, has again detected the evidence of seasonal
changes on the Martian surface during the present opposition.
The observational evidence consists chiefly of colour changes
on the various well-known areas, and was first noticed by
Lampland on April 4. The most prominent feature is seen in
the Mare Erythrjeum, just above the Syrtis, which has again
altered from blue-green to chocolate-brown. The Martian
season at the time of observation, April g, corresponded to the
terrestrial February.

* * »

The Lens Mirror Telescope.

In an excellently-worded booklet, Mr. G. Whittle, of Liver-
pool, describes the construction of a new form of lens-mirror
telescope that he has recently devised. In this the reflecting
surface consists of the back of the lens, which is silvered and
varnished, thus being completely protected from deterioration.
Moreover, the length of the telescope body is greatlv reduced.
The lens adopted is a concave-convex for the main mirror,
and a small meniscus is employed near the focus as a secondary
mirror on the Gregorian plan for magnification. We have not
had the opportunityof using the instrument, but its adaptability
is stated to depend mainly on its absolute achromatism, and
perfect intcvnal reflection from a surface of pure silver
deposited on a true surface of optical glass.

The Gregorian mounting has been chosen on account of the
resulting image being in an erect position.

* * *

The New Solar Observatory on Mount
Wilson in California.

Recent changes in the arrangement of the stafl'of the Yerkes
Observatory, resulting in the transference of its former
Director, Professor G. E. Hale, to the superintendence of the
new solar observatory established by the Carnegie Institution
on Mount Wilson. Pasadena. California, will probablv mark
an important epoch in the progress of scientific astronomical
investigation.

It was only after very exhaustive preliminary tests that this
station was selected by Professor Hale and his colleagues, and
the numerous data supplied fully support their decision.
Situated at an elevation of nearly 6000 feet, the station affords
exceptional facilities for many solar investigations which
cannot be efliciently carried out at places nearer sea-level.
The plan of work outlined for the Institution includes : —

I. Frequent measurements of the heat radiation of the sun
to determine whether there may be changes during the

sun-spot cycle in the amount of heat received from the
sun by the earth, and in the relative radiation of the
various portions of the solar surface.
2. Studies of various solar phenomena, particularly through
the use of powerful spectroscopes and spectrohelio-
graphs.
3. Photographic and spectroscopic investigations of the
stars and nebula: with a very powerful reflecting tele-
scope, for the principal purpose of throwing light on the
problem of stellar evolution.

From the records now in e.xistence, it appears that solar
observations will be possible on 300 days of the year, and the
mean daily range of temperature only varies from 18-5° F. in
April to 27- 1 = F. in November. The anemometer records indi-
cate that the average wind movement is exceptionally low,
indicating a uniform atmosphere. Operations were started
with a 15-inch coelostat and a lens of 6 inches aperture and
6ii feet focal length, and many interesting observations made
on"the effect of heated air rising from the ground across the
sit'ht line of the instrument. By raising the piers as far as
possible above the ground and taking special precautions for
eliminating variations of temperature in the observing room,
it has been found possible to obtain nmch better definition
than usual.

.Associated with Professor Hale in the new institution are
Messrs. Ritchey, EUerman, and Adams, all from the Yerkes
Observatory. They hope to have the 5-foot Snow reflec-
tor available for use very shortly. Two concave mirrors
of 24 inches (61 cm.) aperture, 60 feet (18-3 in.) and 145 feet
(44-2 m.) focal length respectively are to be used for forming
the primary images of the solar disc. The spectroscopic
apparatus to be used in conjunction consists of: —

1. A spectroheliograph with portrait lenses of S inches
|20'3 cm.) aperture and 60 inches ( 152 cm.) focal length,
provided with four dense flint prisms. This will be
floated in mercury, to reduce the friction on the rolling
surfaces. Daily photographs of the entire solar disc
with the calcium and hydrogen lines will be taken with
this, using the image of 67 inches (17 cm.) diameter
given by the concave mirror of 60 feet focal length.

2. A spectroheliograph of 5 inches (127 cm.) aperture and
30 feet (9-I4 m.) focal length, provided with three light
flint prisms of 50- angles. In this instrument the spectro-
heliograph will remain fixed, and the traverse of the
image across the slit obtained by a slight rotation of the
large mirror, and a corresponding motion of the photo-
graphic plate. The whole will be used for studying
special zones of the solar image, and with a plane grat-
ing, for the study of sun spots, &c.

3. A Littrow spectroscope of 18 feet (5-49 m.) focal
length, with large plane grating, to be used for study of
solar rotation and spectrum of sun spots.

4. A large concave grating stellar spectrograph, of about
15 feet (4-57 m.) equivalent focal length, used with a
collimatiug lens of 5 inches (127 cm.) aperture to elimi-
nate astigmatism.

5. A prism spectrograph, with collimator of i* inches
(3-8 cm.) aperture and 48 inches (114-5 cm.) focal
length ; dispersion train of one to four prisms, and
various camera lenses. This will be used in the deter-
mination of wave lengths of stellar spectra, especially in
the ultra violet regions.

The activity of Professor Hale and his staff is well shown
by the recent publication of a beautiful reproduction from a
photographic spectrum of the solar surface. This shows the
violet region, including the H and K lines of calcium, which
are about 4i inches apart. This photograph was obtained at
Mount Wilson with the Littrow spectrograph above men-
tioned, the grating being 4 inches in aperture with 14.43S lines
to the inch, using the third order. An interesting feature of
the photograph'" is the strength of the reversals over the
regions occupied by faculas on the sun's disc, and the scale is
sutflcient to show clearlv that the continuous spectrum of the
facula: rapidly decreases in intensity as it approaches the
centre of Hi and Ki, where it almost disappears. This fact
will prove most useful in future theoretical considerations.

13^

KNOWLEDGE & SCIENTIFIC NEWS.

rj.)

1905.

Ephemeris for Observations of Comet
1904 II.

(i^h.. Berlin Mean Time

I.J05.

K, \.

Declina

lion.

Relative
Brightness.

June I

4- 64

508

016

5I-6

52-6

0-15

53-7

551

0-15

567

58-5

014

0-5

»7

2-8

014

^ i

0 13

II-I

•3

14-3

0 13

I7«

21 5

0-I2

July I

254

29'5

0 12

33-9

38-5

012

432

1 1

- 65

48 2

012

CHEMICAL.

Bv C. A. MiTCHKLL. B..A. ii i.xoii.i, F.I.C,

New Experiments on the Making of
Diamonds.

A BLOCK of meteoritic iron troin Canon Diablo was recently
examined by Professor Moissan, and its composition sug-
gested improvements in the artificial manufacture of diamonds.
A section of the meteorite contained numerous diamonds,
both black and transparent, together with amorphous carbon
(graphite), and phosphorus and sulphur combined with iron.
Experiments were therefore made to determine the influence
of sulphur, silicon, and phosphorus upon the crystallisatioa
of carbon under the artificial conditions of the laboratory.
Iron was fused with a large e.xcess of sugar in a crucible in an
electric furnace, and as soon as the molten iron had become
saturated with carbon (derived from the sugar) a small pro-
portion of iron sulphide was introduced, and the crucible then
rapidly cooled by immersion in cold water. It was found that
the carbon had crjstallised out in diamonds from the centre
of the mass, and that the iron sulphide had considerably in
creased the yield of crystals. Rapid cooling of the fused
mass, however, was essential, for otherwise no diamonds were
formed. Silicon also promoted the crystallisation of the
carbon, but phosphorus had no effect upon the results.
• • •
The Specific Servim Test as a Proof of

Evolution.
Professor Haeckel in his latest work the " l-.volution of
Man," cites the recent results of physiological chemistry as
additional proofs of the origin of man. Although a serum
that has been rendered specific for one species of animal
should give no precipitate with the sera of other animals (see
Knowledok & SfiK.NTiiK Nf.ws this vol. p. 86), the test
breaks down in the case of animals of very closely allied
species, and hence it is not surprising that a preparation that
has been made specific for human serum should also react
with the serum of an anthropoid ape and vice versa. It
would thus be impossible to infer that a given stain consisted
of human blood it there were a possibility of an anthropoid
ape having been near the place. Another possible source of
error in the serum test has been pointed out by MM.
Linossier and Lemoine, who find that the differences are not
so pronounced as has been asserted. They slate that if solu-
tions of too great a concentration be employed, the prepared

sera are no longer absolutely specific, although the preci-
pitates are much more marked with the serum of an animal
of the particular species in question than with the sera of
animals of other species. To obviate this error they recom-
mend that the solutions employed should not contain more
than one part in a thousand.

* « »

The Preparation of Pure Ta.ntalunn.

The rare metal tantalum occurs in various minerals, such
as niobite, tantalite, and samarskite, and is usually found in
association with another rare metal, niobium. Hatchett, in
1801, came to the conclusion that some of these minerals con-
tained a new element, and different chemical compounds
containing it were subse(|ueDtly prepared. It is only quite
recently, however, that Dr. \\". von Bolton has succeeded in
preparing the metal in a state of purity, and in his opinion
the substance prepared by M. Moissan in his electric furnace
was contaminated with carbon. Dr. Bolton's method of ob-
taining it consists in passing an electric current through a
filament of brown tantalum oxide in a globe from which the
air has been previously exhausted by means of a vacuum
pump. This causes oxygen to be evolved from the incan-
descent filament, which gradually turns grey as it is reduced
to the metallic state. Tantalum can also be prepaied by
fusing tantalum fluoride with potassium in a vacuum by means
of an electric furnace. Metallic tantalum, which has an
atomic weight of about iSo, is extremely ductile. When the
sheets are again heated and hammered they become ex-
tremely hard, and the metal may find a possible use as a
substitute for the diamond in drills. Tantalum resists the
action of acids, including iKjiin ligin, and it can be heated to
redness in the air without burning. It forms alloys with
many other metals, but apparently does not amalgamate with
mercury. When combined with about one per cent, of carbon
it becomes very brittle. Messrs. Siemens and Halske have
employed filaments of tantalum for electric incandescent
lamps, and as a length of over 20 inches is necessary for a
lamp of 22candle power, they have constructed a special
lamp for the purpose. The central support Un- the filament is
of glass and has a number of radiating supports over which
the wire is stretched. This lamp is stated to consume only
half the electric energy required by the ordinary incandescent
lamp, while a pound of the tantalum is sufficient for more
than 20,000 lamps, so that a great saving is effected by its use.

GEOLOGICAL.

By EmvAuii A. Maktin, F.G.S.

Gravels on South Norwood Hill.

W'k have received a couiinunicaticjii from .Mr. J. K. I^arkby in
regard to the reputed eoliths found at the top of the hill by
Mr. .\. F. Kobarts, F.G.S., two years ago, to which a reference
was made last month. He has been unable to accept the
flints as true eoliths, and it is to fair to say that others have
questioned their authenticity. On the other hand they have
been accepted as of human workmanship by many of the best
local geologists, and they deserve mention in any work dealing
with implemeiitiferous gravels. We shall all agree with Mr.
Larkby when he says : " Whilst fully accepting the artificial
nature of eolithic forms, I recognise that the indiscriminate
admission of evidence must serve to confirm the impression
that the acceptor of eoliths is ipso /ado a ' crank.' "
« • •

A Lost R.iver.

The gravel which is found .iloiig the valley which leads from
Caterham to Purley gives evidence of an important river which
at one time flowed here. Early last year there was evidence
of the stream in the rising again of what is known locally as
the Bourne. This had not flowed since 1H96, although previous
flowings had generally occurred at shorter intervals. The
rising of the feeders were to be seen at various spots in the
valley, e xtending from the grounds of the " Hose and Crown "
at Warlingham, where they were seen bubbling up at several
places, notably on the site of the cocoa-nut pitch, to the gas-

June, 1905.^

KNOWLEDGE & SCIENTIFIC NEWS.

133

works farther up. At Kenley, where building has been going
on for some time, the gravel has been excavated and sifted. In
a heap of gravel which I examined, in addition to a great
number of sub-angular flints, there was a fair proportion of
rounded stones and pebbles, of Oldhavcn pebble-bed origin.
Many of the tlints had become encrusted with a covering of
lime, after the manner of the action of so-called petrifying
springs. Lumps of conglomerate were also found, and
occasional pieces of red sandstone. The limestone encrusta-
tion of some of the flints clearly showed the present origin of
the feeding springs from the chalk, whilst the presence of the
sandstones takes one back to times when the river had a por-
tion of its flow over the Lower Greensand farther south, and
possibly over some of the sandstone beds of the Weald.
» » »

Pre-Gla.cia.1 Valleys of the Northximber-
latnd and Durham Coalfield.

By a detailed examination of about 600 different borings in the
areaspecified. Dr. D. Woolacott, F.G.S., has reconstructed with
considerable pains some of the valleys which existed prior to the
Ice Period, many of which have been completely hidden since
by thick wrappings of boulder-clay. Although the subsequent
existing drainage systems of boulder-clay areas are in most
cases much the same as those on which they were super-
imposed, there are notable cases in which the subsequent
drainage has been completely different to that previously
obtaining. The greatest thickness of superficial deposits found
was that at Newton Hall, in the Wash valley, when 233 feet
of these lay above the old rock surface. A number of the
borings show the rock-surface at a considerable depth below
sea-level, such at Burdon Main, in the Tyne valley, where
the rock was not reached except at a depth of 141 feet, this
affording good evidence of considerable subsidence, as
compared with pre-glacial time?.

* * *

The Great Peak Fault.

In the course of a paper read before the Geological Society
by Mr. R. H. Rustall. B.A.. on the Blea-Wyke Beds and
the " Dogger " in N.E. Yorkshire, the subject of the age of
this well-known fault was touched upon. The author leaned
to the view that it was partly of pre-Oolitic date. There is
every reason to think, as suggested by Mr. Hudleston many
years ago, that the fault was a distinct line of weakness, and
that probably movement had taken place more than once in
the history of the district. Disturbances in the earth's crust
were apt to follow old lines.

* * ♦

Earthquake in England.

A reminder on a small scale of the earthquake convulsions
which have taken place recently in India was experienced in
the Midlands on the early morning of Easter Sunday. It is
not improbable that the shock had a connection with the
Indian catastrophe. The crust of the earth will for some time
be occupied in settling down, so to speak, into greater per-
manency than it was left after the great underground earth-
slides which gave rise to the Lahore shocks. In fact, anyone
great quake may generally be regarded as the forerunner of
other minor ones, and the shocks so caused may travel to
regions where earthquakes are infrequent.

-^^^^^^

ORNITHOLOGICAL.

By W. P. Pycraft, A.L.S., F.Z.S. , .B.O.U., &c.

Greenland Fa.lcon in Co. Donegal.

In the Irish Naturalist for May, Mr. Robert Patterson records
the occurrence of a Greenland Falcon at Horn Head, Dun-
fanghy, on March 21. The bird was taken in a trap, and
proved to be a female. The total length of this bird from the
tip of the beak to the tip of the tail was i ft. 1 1 ins. ; the expanse
of the wing 4 ft. 3 ins. The weight is not recorded.

Corn Crake in Winter.

Though it is now generally believed that th<! Corn Crake not
seldom remains throughout the winter in Ireland, authenticated
instances of this stay are valuable. Mr. Robert Patterson
records in the Irish Naturalist for May the fact that one of
these birds was shot near Lurgan in January last. In England
such cases are very rare.

Bittern in Co. Wexford.

One of these unfortunate liirds was shot in November, 1904,
at Curracloe, near Wexford. Accordingto Mr. J. H.Johnson,
who records this occurrence, a Mr. O'Neill heard the booming
near his house. This statement requires some qualification, as
the Bittern is generally believed to utter this note only during
the breeding season.

Snowy Owl in the ShetlaLnds.

One of these birds was killed in November last, .according to
the Ayinals of Scottish Natural History for April (which reached
us too late for comment last month) at Ballinata. No parti-
culars are given as to sex or measurements. News has just
come to hand of another Snowy Owl killed in Norfolk during
April last. Further particulars thereof we hope to give next
month.

» * *

Albino Redshank in the Outer Hebrides.

A so-called albino Redshank was killed in October last in
the Outer Hebrides, according to the Annals of Scottish Natural
History for April. This bird, however, should rather have
been described as isabelline and white, inasmuch as buff and
cinnamon appeared conspicuouslv in the plumage intermixed
with white. In true albinos, all pigment is wanting ; hence the
pink iris, which is hall-mark of the albino.

Arrival of Summer Birds.

From The Field for .^pril 22 we gather the following list :-
Garden Warbler — St. Neots April 13

Nightingale

Landrail

Eastbourne

Tonliridge

Shoreham

Shere

Hockley ...

Barnstaple

PHYSICAL.

By Alfred W. Porter, B.Sc.

All who had the privilege of listening to Professor Nichols
(of Columbia L'niversity, New York) at the Royal Institution,
on the 12th May, were delighted with the apparent ease with
which a difficult experiment was shown. The subject of the
lecture was " The Pressure due to Radiation." It had been
predicted by Maxwell that if his electro-magnetic theory were
true, light falling on a body should repel it, and he calculated
the force of the repulsion which would correspond to a par-
ticular amount of light; but this was exceedingly small.
Crookes at first thought he had obtained experimental evi-
dence of this pressure when he discovered that light vanes,
mounted in a partial vacuum so as to be capable of easy rota-
tion, were set in motion when one side of each face was
blackened and light fell on the blackened face. This action,
however, was afterwards traced to the effect of heat and not
to light, and depends upon the presence of residual air in the
exhausted vessel.

This air effect, when at a maximum, is thousands of times
as great as the effect which would exist if no air were present ;
and it is its presence which creates the chief difficulty in
measuring the pressure due to radiation itself.

134

KNOWLEDGE A: SCIENTIFIC NEWS.

IJuNli, 1905.

The apparatus employed by Professors Nichols and Hull
consists of two light mirrors mounted on a horizontal capillary
glass tube which is suspended at its middle by a quartz fibre
about an inch long. \\'hen a strong light (from the sun or
electric arc) is focussed on one of the mirrors, it drives it
back and thereby twists the fibre. The angle through which
the suspended mirrors turn can be observed by reflecting a
second beam of light from another mirror mounted on the axis
of rotation.

The chief beauty of the e.xperiraent consisted in showing
that for a particular pressure of the air the disturbance
arising from it is almost zero ; and most of their measure-
ments were therefore made at this pressure. Bat even at
other pressures the fint motion of the siispiiuial iv/jits is ahiuiys
due to the radiation. The reason of this is that the pressure
due to the radiation acts instantaneously ; but the air effect
depends upon the vanes gradually warming up, so that the
action arising therefrom is always delayed.

The results of Nichols' and Hull's experiments are in satis-
factorj' agreement with Maxwell's theory.

ZOOLOGICAL.

By R. Lydekker.
The Pelatgic Lancelet,

The border-land between vertebrates and invertebrates
naturally possesses an interest surpassinji that which attaches
to what we call ordinary members of the animal kingdom ;
that is to say, to those which conform more or less completely
to a normal type and possess a host of near relations. One
of the most remarkable of these inhabitants of the border-
land is the tiny translucent creature of little more than an
inch in length not uncommon on sandy shores in the Mediter-
ranean, to which our great ichthyologist gave the appropriate
designation of lancelet. Long considered a fish, it is now
regarded as more nearly related to the sea-squirts, or asci-
dians ; and with the latter is ranked as chordate rather than
a vertebrate animal. .Among its many peculiarities is the
absence of any distinct head, the position of the mouth on the
under surface of the anterior end of the body, and the ring of
tentacles with which the opening of the mouth is surrounded.
Many kinds of lancelets are now known, all save one of
which conform more or less closely to the general type. The
exception is a species long represented only by a single
specimen taken during the scientific cruise of H.M.S.
Challenger in the open s(ra. Of this species a number of
specimens have recently been described, and these serve to
show that it is a very distinct type indeed, characterised not
only by its pelagic habitat, but by the position of the mouth
on one side of the body, the absence of the ring of tentacles
fringing the mouth-opening, and several other equally im-
portant structural pecul aritics.

Luminous 2»hrimps.

The Prince of .Monaco, whose aetive interest in the fauna
of the deep sea is well known, is reported to have lately dis-
covered luminous shrimps, which live at a great depth where
all, of course, is dark. When placed in a(|uariiims these
crustaceans soon, however, loo?c their luminous properties.
Probably most, if not all, abyssal organisms arc luminifcrous,
or phosphorescent, some giving forth light from the general
surface of the body, and others from special organs.

The Cak.rnegie DinosaLur.

On May 12th. [...rJ .\vel,iry. on I. half of the TrusteeF,
formally received from Mr. Carnegie the gift of a model of
the skeleton of the great dliiosaurian reptile Diplodocua car-
nei^ii. which has been recntly set up in the reptile gallery of
the Natural Hislorv Mnsenm under the imine;dialc superin-
tendence of Ur. Holland, Director of the Carnegie Museum
at Pittsburg. The skeleton, as now set up, gives a far better

idea of the enormous proportions attained by these gigantic
reptiles than was ever previously possible in this country,
even with the aid of the imperfect skeleton in the Geological
Department of the Museum collected by Mr. A. N. Leeds,
near Peterborough. The skeletons from which the model in
the Museum were constructed were obtained from the Upper
Jurassic formation of Colorado and Wyoming; from which
horizon the late Prof. Marsh long since secured the remains
of the typical species to which he gave the name DiploJocus
longiis. .Vs set up, the skeleton measures about 75 feet in
length, but were the skull and vertebr;c arranged in a straight
line the length would be some ten feet more. At the shoulder
the creature stands about 14 feet in height. The skeleton
is mounted with the head and neck stretched out nearly in
the line of the back ; but we may be permitted to doubt whether
this was the normal attitude of the reptile in life, especially
in view of the fact that the nostrils opened on the top of the
head, which suggests an amphibious existence. Diplodocus
differs from its relatives by its feeble teeth, which resemble
lead-pencils, and are confined to the front of the jaws. Such
a feeble dentition suggests that the creature procured its food
in the water. By his numificent gift Mr. Carnegie has laid all
in this country who arc interested iu natural history under a
deep obligation.

Fossil Marmot Burro>vs.

Some years ago .American geologists described certain large
spirals of hard stone met with in rocks of soft structure under
the name of " devil's corkscrews," or, more scientifically, as
JhTiiKincluiix. How the.se strange and gigantic spirals were
formed h.id long been a mystery, although some naturalists
suggested that they were of vegetable origin. Dr. Holland
has explained that they are really the solidified burrows of a
marmot allied to the existing " prairie-dog " (Cynoiiiys liiduvi-
cianiis). Hence, we presume, Damonohelix becomes the
generic name of a mammal.

The Ma.n-like Apes.

Naturalists will proli.ihly be divided in opinion as to the
value of Mr. Rothschild's paper on anthropoid apes in the .April
number of the Zoological Society's Proceedings, and some
of them, at any rale, will not endorse all his views with
regard to the nomenclature. One of the most interesling
observations records the fact that two different types of orang-
utans are to be met in the same districts, in one of which the
faces of the old males are expanded into a kind of warming-
pan shape, while in the other they are of more normal con-
tour. Mr. Rothschild explains this by " dimorphism," and
regards both types as belonging to a single f pecics, and even
to the same race. Amorg chinipanzis two distinct lyptsare
likewise stated to inhabit the same districts, but lure the
author regards the two forms as separate species, each of
which may have several local races. Whether this explana-
tion of a very curious puzzle will be generally accep:ed
remains to be seen.

Pa-pers R^ead.

.At the meeting of the Zoological Society on April iStli Dr.
A. Smith Woodward read a paper on the skeleton of Cetio-
sauriis (or, as being derived, k^T.7, Ceteosaurtis) o.xoniensis
from the Oxford clay of Peterborough ; while the Secretary
described a young Nigerian giratl'e (diraffd camclopardalis
peralta). As mentioned in our last issue, Mr. A. E. Shipley
described various infernal parasites obtained in the Society's
Gardens and elsewhere, and Mr. R. H. Burns discutsed the
anatomy of the leathery turtle. Messrs. Thomas and Schwann
gave an accoimt of a colUxlion of South -African quadrupeds,
Mr. G. A. Honlenger described a new \'nnnan newt, Dr. I".
Lonnberg noticed hjbrid I'mopean han^s, and Mr. .A. L.
Butler referred fothegiant eland of the Bihr el-flhazal. The
papers read on May 2nd included one, by Prof. Minehin, on
sponges of the group I.cticoselenia, &c., a second, by Mr.
Bf-ddard, on the anatomy of the ferret-badger, and a third,
by Mr. W. P. Pycraft. oii th«! osteology and aftinilies cf the
birds of tjie f.imily KniyUcnidcc.

June, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

135

REVIEWS OF BOOKS.

The Principles of Heredity. G. Archdall Reid, M.B.,
F.R.S.E. (Chapman and Hall, 1905.) This volume is, we
are told, addressed to medical men, the evidence relied
upon being largely drawn from medical sources. Never-
theless the author has so consistently avoided the use of
technical language, and his reasoning is so clear and acute,
that it should prove very interesting to the general reader.

The author commences with a chapter upon the " Theories
of Heredity," following on with chapters upon " Theories of
Evolution. Use and Disuse, and Spontaneous Variation." In
these chapters he reviews the main features of the evolution-
ary theory, as accepted by the majority of biologists of the
present day. The Bathmic theory and the Lamarchian
theories are dismissed as fundamentally opposed to observed
facts, there being little or no evidence to justify belief in the
inheritance of acquired characters, even in the lower forms of
life. The theory that organisms are gradually adjusted to
their environment by processes of variation and selection is
accepted.

The effects of use and disuse are dealt with in a lucid and
most suggestive manner. Man and the higher animals are
described as large superstructures of " acquirements " built
upon comparatively slender foundations of inborn characters.
The hair, the teeth, the nose, the nails, &c., are wholly inborn
characters, and are quite unaffected by use and disuse, but
the muscles of the legs and other limbs, the heart, the blood
vessels, the lungs, &c., can only reach their proper develop-
ment by acquirement, and can only be maintained by the
e.xercise necessary for their acquirement. It is thus clear
that the modifications resulting from use and disuse are not
transmitted to subsequent generations, but only the power of
acquiring modifications under similar circumstances.

Under the title of " Recapitulation " the author endeavours
to establish and remodel the old theory that the development
of the individual is a blurred recapitulation of the history of
the race. This theory, as stated by Mr. Reid, lil<e the many
other theories of " Heredity," contains much truth, but not
the whole truth. Each theory may form a stepping-stone to
some final and completely satisfactorv laws of heredity, but
one feels that the pressing need nf the moment is work. The
laws governing the inorganic world were established by a host
of workers experimenting until a mass of organised knowledge
was accumulated which placed those laws beyond dispute.
Each new work upon this subject impresses one that students
of heredity rely too much upon empirical observation, and
upon the work of the practical man in rearing animals
and plants. Such sources of knowledge are too incomplete
and disconnected to enable us to attain a complete know-
ledge of this important subject.

Under the title of " Biparental Reproduction " we are told
that its tendency is to result in regression to the specific
mean, and that there is not an iota of evidence to prove that
biparental reproduction is connected with variation as a cause
and effect. The author appears to disregard the fact that in
the words of E. Ray Lancaster • : " Breeders of horses, cattle,
and sheep, and dog, pigeon and poultry fanciers, crop growers,
nurserymen, tulip maniacs, and the like cross-
breed here, and crossbreed there, until the specific potential
is broken down and strange and unlocked for variations are
born ana grown up irrespective of strange and abnormal sur-
roundings. From these congenital variations they select the
desired forms, and perpetuate them with perfect assurance
and security." A good example of what can be accomplished
in this manner by biparental reproduction is the result of
some hundred years' work upon the rose. From a compara-
tively few wild forms, many thousands of cultivated species
and varieties have been produced. Chapters upon " Regres-
sion " and the causes of " Spontaneous Variation " conclude
this section of the work, and chapters upon the " Evolution
against Disease," "Narcotics," ".Automatic and Voluntary
Action," " the Mind of Man," Methods of Religious and
Scholastic Teaching," and other subjects treated from an evolu-
tionary point of view, occupy the remainder of the volume.

In a work of this character, extending over a wide field
of knowledge, one naturally finds statements which invite

* Nature, Nivember 29, 1S94.

criticism. Mr. Reid may, however, be congratulated upon
having contributed a work to the literature of evolution in
which he has approached the subject from a new point
of view, and which contains much that deserves careful
attention.

The Tutorial Chemistry.— Parts I. and II., by G. H. Bailey,

D.Sc, &c. Second edition (University Tutorial Press), 3s. 6d.
each part. This work, first issued some ten years ago, has
already earned a good reputation, but modern progress, with
its reforms in the methods of chemical teaching, has demanded
that it should be brought up to date. The main features of
the work have been retained, but Part I. (non-metals) now
contains two distinct sections. Of these, section I. consists of
an introductory course based on a series of simple experiments
and designed to illustrate the leading laws and principles of
the science and to train the student as early as possible in
'■ scientific method." Section II. contains a systematic treat-
ment of the non-metals illustrated by numerous instructive
and typical experiments ; the proofs of composition and con-
stitution form a special feature, and in the case of each
important substance some account is given of its history and
the purpose for which it is employed. Part II. (metals) also
consists of two sections, section I. being anaccount of physical
chemistry, which has been here brought completely up to date.
Section II. is a full account of the metals; the chemistry of
radium, electro-chemical methods for extraction of metals, the
determination of atomic weights, and many other matters of
interest depending upon recent researches and discoveries
have received special attention. The book, as it now stands,
gives a complete account of chemistry as usually studied for
University final degree examinations. For intermediate science
students of London University who wish to keep closely to its
syllabus, asterisks have been placed to those paragraphs
which do not fall strictly within the scope of the examination.
There are one or two instances in which one might have ex-
pected the book to be rather more up-to-date. For instance,
very little is said about calcium or the new method of obtain-
ing it. The new alloy " Invar " is not referred to b\' name, nor
can we find any allusion to the recently discovered magnetic
alloy of copper and manganese.

Modern Industrial Progress, by Charles H. Cochrane (Lip-
pincott Co.), price los. Gd., is really a very fascinating book.
It is not by any means a scientifically accurate account of this
exhaustive subject, but the story is well told, the illustrations
profuse and alluring (if not always very correct), and the
matter abundant and of great variety. We are told of elec-
tric generators and .X-rays, of electric trains and " converters,"
of wireless telegraphy, of steel manufacture and the treatment
of ores, of aerial navigation and kites. Evolutions in vehicles
and roadways, in ships, and in tools of destruction are
described, as are canals and tunnels, timber gttting and work-
ing, mining, food, and water. Engineering enterprises of all
sorts are gone into, and, in fact, to give even a list of the
matters which are here attractively described would fill
more space than we can devote to it. What is here tcld must
be taken with — well, a milligramme — of salt, but this minute
saline admixture does not detract from its forming a very
readable and even instructive book.

N-Rays : A collection of Papers communicated to the
Academy of Sciences, by R. Blondlot ; translated by J. Garcin
(Longmans, Green and Co.; price 3s. 6d. net). — Professor
Blondlot has experienced in his efforts to make known the N-
rays the truth of the maxim that the way of the scientific dis-
coverer is hard ; and though other theorists before him have
had to battle quite as hard for their theories, it is doubtful
whether the scepticism expressed about the reality of the
phenomena he has observed has ever been quite of the same
kind. One might say that the sceptics, except in France, still
outnumbered the disciples, and that the proselytes were few
in number. But in a case of this kind one piece of affirmative
testimony must outweigh a great deal of negative evidence,
and M. Blondlot's critics^are divided among themselves, some
maintaining that the alterations which the hypothetical N-
rays produce in the luminosity of a testing screen are due to
heat, while others say that the alterations do not exist at all.
In the domain of affirmative testimony there has lately
been added evidence of the greatest importance from Pro-
fessor Hackett, of Dublin University, who has attained such
definite results that he is able to discern, through the aid of

136

KNOWLEDGE >S; SCIENTIFIC NEWS.

[June, 1905.

his detector screen, the emission of N-rays from a silent
tuning fork ; and from Professor Broca, who has examined
and distinguished the so-called physiological causes of the
rays. We may perhaps sum up the case for the real existence
of the rays by a method of questions and answers. Is the
change (in the detector screen) due to physical causf s pro-
ceeding to the screen? If so, then the physical existence of
the N-rays, or of something analogous to them, is established.
Is the phenomenon due to changes produced within the eye
itself? If so, then physiology must explain all the correlated
and complicated phenomena which result — in terms of optica!
illusion such as the structure of the eye could produce.
Lastly, is the phenomenon due to the mind of the observer?
Then, if so, psychology has a task similar to that we have
suggested for physiology. If on the contrary all these hypo-
theses are false, and there is no appearance of change in the
detector screen : that is to say, if, in other words. M. Blond-
lot, Professor Charpentier. Professor Hackett, M. Broca, and
M. dWrsonval are united to bear false witness, the whole
matter seems one for the alienist, for such a tissue of related
and corroborative falsehood was never before recorded. We
do not hesitate to say. therefore, that we believe the establish-
ment of the objective reality of the N-rays to be merely a
matter of time and careful experiment. This end will be
furthered by the translation before us of the extremely straight-
forward, clear, and workmanUke papers which M. Blondlot
has communicated to the Paris .-\cademie des Sciences. Here
we have collected his own observations, the gradual process
of development of his exDeriments. and his candid efforts to
meet and reply to criticism. No one can pretend to pass
judgment without carefully reading this collected series of
papers, to which additional value is given by M. Blondlots'
directions for preparing the detector screens. A screen of the
kind is furnished as a frontispiece to the work ; and we cannot
do better in taking leave of it than to quote M. Blondlot's
warning as to the method of observation of N-rays: "It is
indispensable in these experiments to avoid all strain on the
eye, all effort, whether visual or for eye accommodation, and
in no way to try to fix the eye upon the luminous source
whose variations in glow one wishes to ascertain. . . In
fact, the observer should accustom himself to look at the
screen just as a painter would look at a landscape. To attain
this requires some practice, and is not an easy task. Some
people, in fact, never succeed."

On False Education, by Frederick Hovenden, F.L.S., F.C.S.,
F.K.M.S. (Watts; price 3di. — It is perhaps invigorating and
salutary occasionally to read attempts to upset and prove
illusory one's deeply-imbibed dogmas, or at all events to hear
• hem investigated, dissected, and criticised. We have been
brought up to believe in mathematics as a subject deserving
of our highest respect ; infallible, conclusive, beyond argu-
ment. Yet here we are suddenly confronted with an assertion
that the whole thing is a mockery and a delusion I Arith-
metic exists : two and two still make four. Multiplication
is but addition repeated ; two and two and two, that is, two
added three times over, make six. But according to this
author, 2 X 3 is not at all the same as 3 x 2. Algebra is
delusive ; 2rt x 3'' is nonsense ; as well say multiply two apples
by three pears ! All this starts one thinking. Where arc we ?

What Do We Know Concernlni; Electricity? by A. Zimmern,
B.Sc. Pp.140. (Methuen and Co., London; is. 6d. net). —
This is a delightful elementary account of electrical phenomena
intended for readers who may wish to obtain some knowledge
of the subject, and who " yet may not have the desire or oppor-
tunity to make a thorough study of the subject." The aim of
the author will certainly be fulfilled. Simple though the lan-
guage is, it seems to be wonderfully accurate; and throughout
a style which appro<aches distinction is maintained. The
following extracts — which refer to different questions — will
illustrate the author's cautious attitude : " The pictorial repre-
sentation fof the processes of electrolysis] which scientists
now adopt as' a ' working hypothesis ' is this ! " " The modern
conception of an ether is an invention due to Huyghens. I
use the word invention advisedly because we have no experi-
mental evidence for its existence. . . . Yet . . . there
is a great and increasing amount of circumstantial evidence
for the existence of somf</ii(i(^ of which the ether as we conceive it
is the expression suited to our present knowledge." This is excel-
lent. We leave the book with regret that we have not referred
to"t)ie chapters on the passage of electricity through gases and
on radio-activity.

Bacteriology. — .A. Laboratory Guide in Elementary Bacteri-
ology, by William Dodge Frost, Ph.D. Third edition (Mac-
millan; price. 73. net). -If one wished to review Dr. Frost's
guide to the bacteriological student in the shortest possible
number of words, one would say that it was exactly what it
professes to bs in its title. It details for the student the exact
methods that he will have to follow in the bacteriological
laboratory in order to obtain a thorough working knowledge
of the science, and to fit him for more extended research.
It is arranged with two ideai in view ; the first, and perhaps
the more important, to indicate the experiments which a
student will have to make and the best way of making them —
and in this respect the third edition differs from those which
have preceded it by substituting new and improved methods
of established examinations of bacterial cultures; and. the
second, the best order m which to take these experiments. Thus
we proceed from the making of bouillon for cultures to the
inoculation of animals and the bacteriological examination
for human autopsies. The second subdivisional arrange-
ment of Dr. Frost's volume is that which suggests the studv
of the various bacteria in groups, the most logical and
reasonable method, and the one which is most in keeping
with recent tendencies. It is a most valuable and practical
manual.

Sociology. — Sociological Papers, by Francis Galton, E.
Westermarck, P. Geddes. E. Durkheim, Harold Mann,
V. V. Branford, and James Bryce. (Published for the Socio-
logical Society: Macmillan). — The contents of this volume
consist principally of the papers read before the Sociological
Society last year, and amid a mass of interesting material,
the essay by which Dr. Francis Galton strove to establish the
new science of " Eugenics " is. perhaps, the most important.
Dr. Gallon's idea is that we niav establish the coming race,
sound in wind and limb, in mind, and in morals, by selective
breeding. It is a hypothesis which we believe to be vitiated
by the fact that we do not know what to breed for ; that it
is not the fittest that survives, but tiic more fit; and short
of exterminating the unfit at birth, a proceeding to which
mankind still entertains a sentimental objection, we do not
think any method of artificially improving the births of the
world would effect much. More entertaining, however, is
Dr. Gallon's effort to remedy a noticeable omission in the
annals of talent. We have many biographies of great per-
sons, but no collection of biographies of gifted families; and
since it is probable that brain is as much a heritage as bone
or muscle, it is as well for those who wish to improve the
race to know how far and in what directions the cleverness
of a pareot is transmitted or inherited. Dr. (^lalton's way
was to send a letter to Fellows of the Royal Society asking
them to give particulars of the noteworthy achievements of
their near relatives ; and from the 250 replies received, he
arrived at the general conclusion that ability as measured
by achievement tended to be a family characteristic in
a marked degree. Achievement as a rule was measured
by mention in the " Dictionary of National Biography,"
m the " Encyclopiedia Britannica," and in a lesser degree
in " Who's Who ? " but besides families distinguished in
this way, there were others whose members were reputed
to have a high level of ability. We each of us have on
an average ten near male relatives who live long enough to
attain distinction if they have it in them — two grandfathers,
one father, two uncles, one brother, and four first cousins.
Usually distinction is sufficiently rare to make it probable
that if one of these ten reaches Dr. fialton's standards of dis-
tinction, there is genius in the family ; but Dr. Gallon's statis-
tics show that where Fellows of the Royal Society are con-
cerned there is the average of no fewer than four distinguished
persons in the ten. Some of the family trees are so remark-
able as to be worthy of special notice — that of the Darwins,
for instance. Charles Darwin was the grandson of lirasmus
Darwin, F.R.S., physician, poet, and philosopher ; and of
Josiah Wedgwood. F.R.S. He was the son of Robert Darwin,
F.R.S., a distinguished physician ; ;ind was the nephew of
Charles Darwin, who h.id a career of extraordinary promise.
He was, of course, related to other descendants of Josiah
Wedgwood, and to the Galton family among them. Of his
four sons, Francis, George, and Horace are all I-"ellows of the
Royal Society, and Leonard Darwin is a brilliant scientific
Engineer officer. Similarly, the Horslcys are related to the
Hadens, the Brunels, and the Bramwells.

June, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

137

Photography-
Pure and Applied.

By Chapman Jones, F.I.C, F.C.S., &c.

Tlie selection of a pnniing process. — In scientific work
one is often satisfied with the production of the nega-
tive, and sometimes rightly so, but for demonstration,
reproduction with letterpress, storing for convenient
reference, and in other cases, it may be desirable, if
not necessary, to make prints. In one sense a print
must always be inferior to the negative because it is
a stage, further from the original, but it may be practi-
cally far superior because it gives the photographer
further opportunity for making more conspicuous the
very matter that he wishes to investigate or demon-
strate. In the choice of a printing process there are
more possibilities than are generally recognised.

There are now to be obtained silver printing-out
papers specially prepared for giving vigorous prints
from poor and flat negatives, and by the use of them
important detail in a photo-micrograph or a spectrum
photograph that is feebly represented in the negative
may be made much more conspicuous, .'\mong de-
velopment papers, slow bromide or " gas-light "
papers are specially suitable for this purpose. A
smooth surface should always be selected, and if it is
made more shiny still by drying it on a sheet of ebonite
(or glass or ferrotype iron), the detail will show still
more markedly. It may be that in a print so obtained
much of the other parts of the subject will be lost in
obscurity, but then it is easy to prepare another print
on an ordinary paper, making the best of the subject
as a whole, and to show this with the special print of
the particular part that needs emphasis.

If it is desired to show the general characters of a
subject without special emphasis of detail, as may be
the case with photographs of some geological sub-
jects, a rougher surfaced print is an advantage. A
matt-surfaced bromide print, or a print on a paper that
has no layer of medium on it (gelatine or albumen),
such as platinotype paper and some silver papers, will
serve this purpose. Here the detail will not be lost,
but it will be less obtrusive.

If permanency is the chief desideratum, there are
three processes that specially come to mind, namely,
platinum and carbon printing, and the production of
enamels. Of these, undoubtedly the most convenient
for those who do not make a business of photography
is printing in platinum, and, although it is making
rather a fine distinction to compare the probable last-
ing properties of these three kinds of photographs, I
think that a platinum print would probably out-live
the others. If it were my duty to prepare photographic
records for the express purpose of being in usable
condition a thousand years hence, I should be inclined
to prepare prints by these three processes, unless the
subject was too large for making an enamelled plate
from it, and then I should not much regret having to
rely on the other two. But if I omitted to prepare
platinum prints, I should feel that I had not been
faithful to my trust. If a platinum print is not brilliant
enough to clearly show the detail to which attention is
to be directed, it may be waxed, a process that used
to be in vogue years ago in connection with silver
prints, but is rarely used now. For this purpose white
wax is melted with turpentine in such proportion that
the mixture, when cold, is of the consistency of a thin

pomatum. This is applied to the surface of the
mounted print by means of a small flannel pad with a
light polisiiing movement similar to that adopted when
"French polishing" wood-work.

Gelatine v. Collodion, etc. — It has sometimes been
deplored, for the sake of experimental rather than
practical photography, that collodion has given place
to gelatine as the vehicle of the sensitive salt. Gelatine
is supposed to be comple-v, variable, and uncertain,
and no doubt it justifies its reputation, but whether
the collodion film is either more simple, stable, and
reliable is open to considerable doubt. Those who
iiave stored both gelatine and soluble guncotton will
know that the former appears to remain unchanged
indefinitely, while the latter cannot be preserved in a
glass bottle for very long, because of the continual
evolution of acid vapours that must be allowed to
escape, and that if stored as is usual in paper lined tin
canisters or cardboard boxes, the paper gets rotten
and the tin corroded. It is too often taken for granted
that guncotton is merely cellulose nitrate, and that the
sulphuric acid used with the nitric acid in its prepara-
tion merely facilitates the action of the nitric acid on
the cotton, perhaps chiefly by its dehydrating action.
But it has long been known that sulphuric acid has a
specific action of its own upon cotton, and Messrs.
Napier Hake and R. J. Lewis have recently shown
[Jnl. Soc. Chem. Ind., 29th April, 1905) that cellulose
sulphates are generally, and probably always, formed
in small quantities in the preparation of guncotton, and
that they often, if they do not always, remain in the
finished product, and are an element of instability.
This investigation refers to the guncotton of warfare,
and photographers who refer to the paper should bear
in mind that soluble guncotton or pyroxyline is pre-
pared with far less care than the other.

Experimentalists who want a pure sensitive film free
from the uncertainties of either gelatine or collodion
have sometimes regarded the daguerreotype process as
very advantageous. But even here there are uncer-
tainties, for General Waterhouse has shown that an
ordinary clean silver surface is sensitive to light, while
if thoroughly cleaned by heating and treatment with
acid it becomes insensitive. These is little doubt that
whatever support or medium is used for the sensitive
salt, its character must be taken into account in in-
vestigational work, and that none of those hitherto
shown to be available can be regarded as inert. But
this is no justification of the extreme view that has
sometimes been expressed to the effect that the sensi-
tive substance in ordinary plates is not silver bromide,
but a product of the action or combination that has
taken place between it and the gelatine.

Radiation or Emanation.— The. fact that many sub-
stances give off something, whether a radiation or a
gaseous emanation, that produces the developable con-
dition in gelatino-bromide plates is being gradually ex-
tended. The latest additions to the list of " active ''
substances are mercuric cyanide, mercuric chloride, a
few other mercury salts, and a compound of mercuric
cyanide with phe'nylhydrazine. Metallic mercurv-vvas
found to be quite inactive, as Dr. Russell stated it to
be some years ago. Messrs. R. de J. F. Struthers and
J. E. Marsh have obtained these results, and further
details concerning them will be found in their paper
published in the Journal of the Chemical Society for
A pril (p. 377)-

We regret that the word actinism in two places i
spelt activism-contrary to author's copy.

the May issue appeared

138

KNOWLEDGE lV SCIENTIFIC NEWS.

[June, 1905.

Cunditcted by F. Shillkngton Scales, f.k.m.s.

Photo-Micrography with Ultra-Violet
Light.

The resolution of a microscope objective is deter-
mined by its aperture, and though the use of immersion
objectives has enabled us to increase the latter, and,
consequently, the former also, to an extent undreamt
of in the days when we were limited to the use of
lenses used drj", a suitable all round medium has net
yet been discovered which will satisfactorily replace
cedar oil and so enable objectives to be made of still
greater aperture. True, an immersion lens has been
made which is used with mono-bromide of naphthalene,
and which has a proportionately greater aperture even
than those used with cedar oil, and, therefore, greater
powers of resolution, but this medium is, unfortunately,
not a suitable mounting medium for most objects, so
that the lens is but little used. Without entering into
the diffraction theory, it may be stated that with an
objective of given aperture — say 1.4 X..'\., w'hich is
approximately our present practical limit — we can only
increase the resolution by reducing the velocity of the
light by which we illuminate the object — that is, by
increasing the refractive index of the medium in which
the object is mounted — for example, when it is mounted
in realgar, or by using light of shorter wave-length.
The first method has, of course, its limits as already
mentioned, but there remains the second. Now, it is
well known that white light is made up of rays of
different refrangibility, and, accordingly, of different
wave-lengths, of which those at the red end of the
spectrum are the longest, and those at the violet end
the shortest. Therefore, mono-chromatic light,
selected by means of a prism or screen, and taken from
the blue, or, still better, the violet end of the spectrum,
will give us greater resolution than ordinary white
light which combines so many rays of longer wave-
lengths. This fact is taken advantage of in photo-
graphy, and the result is a very definite increase in
resolution, say, of the markings of a difficult diatom.
U'hen violet light is used the eye is, unfortunate!}',
little sensitive to these rays, so that it is not easy to
see the object, and though such light has high actinic
value, it is difficult to focus the object satisfactorily
when it is used. Dr. Kohler, of Jena, has, therefore,
experimented with ultra-violet rays, which are in-
visible, but can be used for photography, and their
still shorter wave-length, 275 ^m. has proportionately
greater resolving powers. The lenses are made of
crystal and fused quartz, and as mono-chromatic light
is to be used, they need correction only for spherical
and not for chromatic aberration. The light is ob-
tained from electricity passing between cadmium
electrodes. But the human eye, as we know and have
just stated, cannot sec these rays, and so cannot focus
and adjust them. Therefore, Dr. Kohler has devised
what may be called an artificial eye; in other words, he
constructs what corresponds to an eye-lens, made of
crystal, and a retina made of fluorescent glass, which

responds to these ultra-violet rays. The image on this
■' retina " is examined visually by means of a lens, in
which case Dr. Kohler has found magnesium light, of
wave-length 280 M/i, better than the cadmium light.
The fluorescent light, however, is, unfortunately, harm-
ful to the eye, and, apart from this, the best results
are given by photography. The objects, mostly
organic tissues, have been so far mounted in dilute
glycerine or in salt solution, and structure has been
made evident, which, before, required staining to
bring out, morv? especially because of the comparative
impermeability of certain structures, such as the horny
layer of the skin, and plant membranes. The lens and
its adjuncts were made by the firm of Zeiss, and has
recently been exhibited at the Natural Science Club in
Cambridge. It may have considerable possibilities.

Royal Microscopica.1 Society.

April 19, at 20, Hanover .Square, Dr. Dukinfield H.
Scott, F.R.S., President, in the chair. The Secretary
read a description c;f an old portable microscope made
by W. and S. Jones, which was said to have been the
pocket microscope of Dr. Jenner. Mr. W. J. Dibdin
exhibited a slide of Bacillus typhosus., and explained
the method adopted in staining and mounting. He
also exhibited photo-micrographs of the slide at magni-
fications of 2,500 and 5,000 diameters, with the flagella
well displayed. Mr. .'\. E. Conrady gave a resume of
his paper, " On the Application of the Undulatory
Theory to Optical Problems," illustrated by diagrams
shown upon the screen. Dr. Spitta said that in using
the method of graphical representation, Mr. Conrady
rendered the subject intelligible to most people, and
inquired if the method of explaining the subject
originated with the author, as he did not remember
having seen it in any of the text-books. Mr. Conrady
said the method was not devised by himself, but would
be found in the article on the Wave Theory, by Lord
Rayleigh, in the " Encyclopaedia Britannica."

Quekett Club Journa.!.

1 he h:ill-vearlv issue ol lliis j()urii:il contains ralher
less matter than usual. It appears from the .'\nnual
Report that owing to an increase of rental it was found
necessary to economise in the Journal by shortening
the reports of meetings — which is probably not much
loss — and in omitting the reviews of books, which were
a useful feature. However, I am glad to see that the
membership has considerably increased during the past
year, and that the finances of the Club are in a satis-
factory condition. The Journal contains Dr. Spitta's
address on " Improvements in Modern Objectives," a
translation by Mr. Rheinberg of Prof. Ambronn's re-
view of Prof. Abbe's work, and other papers and notes.

Watson-Conrady Photo-Micrographic
Apparatus.

Mr. A. E. Conrady has computed for Messrs. W.
Watson and Sons an entirely new system of lenses for
photo-micrography, which I have found to give better
results than any other apparatus which has come under
my notice. It is mounted in the modern way on an
optical bench, by means of which each part is capable of
ready adjustment whilst keeping in exact alignment,
centring screws being provided for the preliminary ad-
justments. Taking the parts in order we have first a
source of illumination. This may be by arc light or by
oxy-hydrogen jet, mechanical adjustments, both vertically
and horizontally, being provided, and the whole enclosed

June, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

139

in a Russian iron case. The usu il lar^^e condenser of
two simple plano-convex lenses is replaced by an achro-
matic and aplanatic doublet about 2 J ins. diameter, which
projects a sharp, enlarged, aerial image of the source of
light. The corrections of this condenser are of an un-
usually high order. Condensers of four inches or more
have generally been considered essential, but a little
consideration will show that no microscopical apparatus
can utilize a cone of light of so large an angular extent,
whilst the spherical aberration of all but the innermost
zone of such uncorrected condensers is so considerable as
to render the greater portion of these lenses quite useless
for practical purposes. Thus the small but really aplana-
tic condenser yields a brighter illumination than could
otherwise be utilized, because losses by absorption and
reflection are reduced to a minimum, whilst those due to
spherical aberration are entirely done away with. In
fact, the clear diameter even of this condenser is too
large for most microscopical purposes, and an iris dia-
phragm is therefore provided close to the lens so that its
aperture may be reduced to any desired extent. The
condenser is so adjusted as to project an aerial image of
the source of illumination from 10 to 15 ins. away from
the microscope stage — i.e., at a suitable distance from the
sub-stage condenser of the microscope. In the plane of
this aerial image is provided a second iris diaphragm, by
means of which the flame image can, if necessary, be re-
duced to such a size as will just cover the amount of
object that is to be photographed. This second iris dia-
phragm also materially assists in diminishing internal
reflections in the microscope tube. A thin auxiliary lens
is provided as an accessory which, when placed close to
the intermediate diaphragm, forms an image of the large
condenser on the iris of the second condenser, thus
collecting all the light passing through the latter, and
filling even large sub-stage condensers with light. For
low powers the large aplanatic condenser alone can be
adjusted so as to project an image of the source of light
on the diaphragm of the lens in use, thus evenly illumma-
ting objects two inches or more in diameter. The usual
cooling trough is provided. I have been using this
apparatus for some time and have found that the neces-
sary adjustments are very readily made by means of the
iris diaphragms, and that once made they require but
Ittle subsequent alteration; in fact, it is only a matter of a
fewminutestoremovethemicroscope from the table where
one is working and to place it m position for photography,
with the knowledge that very simple adjustments will
give perfect optical results. The condenser not only
gives unu ually perfect illumination, but very consider-
ably reduces the necessary exposure. I do not, of
course, mean to imply by this that successful photo-
micrography is merely a question of optical adjustment
and exposure.

Notes and Queries.

J. E. Blomficld [Scvcnoaks). — I am afraid you will not find
anyone who lays himself oat to supply the rarer fresh-water
algae. I have made inquiries here and cannot hear of any
such person. An advertisement might be of use. Do you
know Prof. G. S. West's " British Fresh-Water Alga; " ? — it
contains useful hints as to collecting.

John Hume {Nc-u'casllc-on-Tync). — Soft sections want very
careful dehydrating and clearing. The alcohols must be care-
fully proportioned, as 30 per cent., 50 per cent., 75 per cent.,
and 95 per cent., and the section should stay a good time in
each bath. It would be best to clear in xylol and mount
in xylol-balsam, and it would be advisable to have an inter-
mediate bath of hall xylol and half alcohol between the 95

per cent, alcohol and the xylol. Perhaps also your sections
are too thick, in which case they do not get properly per-
meated with the media and shrinking at one stage or another
is very likely to happen. Benzine and benzole are different
names for the same substance. Sections preserved in alcohol
cannot be stained with carmine or haematoxylin made up as
watery stains — alcoholic solutions must be used. Probably
your trouble is due to your overlooking this fact. Eau dejavelle
is practically hypochlorite of potash, and in using it you
are putting back into the section the water which the alcohol
had removed, alcohol being essentially a dehydrating agent.
Sections stained with a watery solution of haematoxylin
should mount well in glycerine jelly if properly stained. After
staining, they should be washed in tap water, not distilled
water. This deepens and fixes the colour, owing to the calcium
salts it contains.

jY. L. Gillespie (Fulham). — Slides for sending abroad are best
packed in the little wooden boxes which can be obtained from
the opticians, fitted with upright racks. They are very cheap.
Each slide should have its edges well packed into the rack with
cotton wool. A good way, however, is to fold a strip of paper
of suitable length into a strip one inch wide, so that it contains
several thicknesses of paper, and then fold two such strips in
and out between the ends of the slides, one strip at each end, in
in such a way that a double tongue of the strip lies between
the ends of each slide, projects inwards for about an inch (not
reaching the mount), and so separates it from those imme-
diately above and below. The nest of slides is then tied
tightly round with string and carefully packed in any haudy
box. Care must, of course, be taken that the last slide of
the nest has its mount turned in.vards for protection like the
others.

/. Cooper (Wi'^an). — The best pocket lenses are those made
on the Steinheil principle. They are aplanatic — which means
flat in the field right up to the margin of the lens — and achro-
matic, or free from colour. They are of brilliant definition
and a great comfort to the eyes. Such lenses are known as
aplanatic pocket lenses, and are made by all the leading
microscope makers (see the advertisement columns of this
Journals and there is little to choose between them. They
cost from 12s. to 153. each, and the powers run 6, 10, 15,
and 20, or thereabouts. I think 5 is the handiest size, and
certainly it is the most comfortable to use ; the higher powers
are very tiring to the eyes. The lens should be mounted for
the pocket.

/. Strachan (Ballyclare). — With reference to my recent
article on the Fibrous Constituents of Paper I must confess
that I have never found anj- quantitative method of esti-
mating the percentages of various fibres to be trustworthy,
except in a very rough and ready way. Your method of
counting the various fibres is probably the best and is accurate
within its limits, but is very laborious ; and I am afraid I
must ask you to forgive me if I am not able to check your
results as my time is very fully taken up with work of many
kinds. If you will be good enough to send on the samples
of chemical wood pulp and mechanical wood pulp, which
you kindly offer, I shall be glad to accept them on behalf of
my readers, and to distribute them to any who care to apply,
provided they will enclose a stamped addressed envelope for
the purpose.

A. H. Glaister (Darlington). — Your method of marking the
actual magnification on the negative of a photo-micrograph
has been ofte.i used, but I am obliged to you for your com-
munication; and as some of my readers may not know of it,
I will give the method herewith as emanating from you.
Briefly, it consists in first taking a photo-micrograph and then,
without altering the adjustments of camera-length, tube-
length, eyepiece or objective in any way, of replacing the
dark-slide by ground-glass, and projecting thereon the lines of
an ordinary stage micrometer. The distance between the
lines is then marked on the edge of a slip of paper, and this is
used as a template, by which the marks can be scratched
across the negative at the side of the photograph. The
value of the lines is added, and the whole reproduces on the
positive as part of the photograph.

[Communications and enquiries on Microscopical matters are invited,
and should be addressed to F. ShiUington Sc^ihs, "Jersey,"
St Barnabas Road, Cambridge ]

I40

KNOWLEDGE & SCIENTIFIC NEWS.

[June, 1905.

The Fa^ce of the Sky
for June.

By \V. Shackleton, F.R.A.S.

The Sun. — On the ist the Sun rises at 3.52, and sets at
8.4 ; on the 30th he rises at 3.48, and sets at 8. 18.

Summer commences on the 22nd, when the Sun enters
the sign of Cancer at 3 a.m. ; on this, the longest day,
he rises at 3.45 and sets at 8.18.

The equation of time is only 6 seconds on the 14th and
15th, hence these are suitable dates for adjustmg sundials
by the clock, as correction for longitude need only be
applied.

The solar cycle is approaching a maximum, and sun-
spots may be observed on any clear day, whilst spectro-
scopic observations of the Sun's limb have, of late, shown
many fine prominences.

The position of the Sun's axis aud equator, required for
locating the spots, is as follows : —

T^,,„ Axis inclined from N.
"^'*- point.

Equator N. or S. of
Centre of disc.

June I .. 15° 33' W.
., 10 .. 11° 59' W.
.. 20 .. 7° 41' W.
,, 30 .. 3° 10' W.

0° 28' N.
0° 37' s.
1° 49' S.
2" 57' S.

The Moon : —

June 3

Phases.

# New Moon
]) First Quarter
O Full Moon
d Last Quarter

5 57 a.m.

t 5 p.m.

5 52 a.m.

7 46 p.m.

Jane 14 . .
.. 25 ..

Perigee 227,500 miles.
Apogee 251,200 ,,

I o a.m.
II 48 p.m.

Occult ATiONS. — The only occultations occurring before
midnight are as follows : —

Date.

June

Star's Name.

1' Virginis
1* Virginis
20 Capricorn!

Magni-
tode.

61
49
5-5

Disappear-
ance.

Reappear-
ance.

7.56 p.m. 8.41 p.m.

8.22 p.m. 9.24 p.m.

(Star below I 10.52 p.m.
horizon.)

The Planets. — Mercury is a morning star during the
former part of the month, and is in superior conjunction
with the Sun on the 24th. Throughout the month the
planet is not well placed for observation.

Venus is a conspicuous object in the early morning
sky, rising about 2 a.m. near the middle of the month.
The planet is at greatest brilliancy on the 2nd.

Mars comes to the meridian at an altitude of 23' shortly
before 9 p.m. on the 15th, and is situated near the double
star o Libra; he is readily distinguished by his bright-
ness and ruddy colour. The diameter of the planet is

16' ; t'ae disc as seen through the telescope appearing
slightly gibbous with dark markings in the southern
hemisphere. The northern hemisphere of the planet is
inclined towards the earth, but the snow cap is scarcely
discernible, as the season of this hemisphere on Mars
corresponds to our early September. The planet is at
the stationary point on the i8th, after which his motion
is direct or easterly ; on the evening of the 13th the Moon
is 6 N. of the planet.

Jupiter is a morning star in Aries, rising at 2.0 a.m. on
the 19th.

Saturn is a morning star in Aquarius, rising shortly
before midnight near the middle of the month. The
planet is stationary on the 14th.

Uranus is in opposition to the Sun on the 24th, hence
about this date he is on the meridian near midnight, but,
on account of his great southerly declination, he only at-
tains a meridian altitude of 15 =. The planet is situated
about midway between the stars ix and x Sagittarii, and
although just perceptible to the naked eye, is readily
found with slight optical aid.

Neptune is in conjunction with the Sun 011 the 30th,
and consequently is unobservable.

Meteor

Showers

:—

Date.

Radiant.

Name.

Characteristics.

R.A.

Dec.

June— July
June 13

h. m.
17 16
20 40

— 21°
■ 4- 61°

0 Scorpiids
a Cepbeics

Fireballs.
Streaks, swift.

Double Stars. — o Librae, XIV.'' 46™, S. 13° 39', mags.
3, 6 ; separation 230" ; very wide pair.

/9 Scorpii, XVI.'' C", S. 19° 33', mags. 27, 5-2 ; separa-
tion 1 3"- 1.

M 80 (Scorpio). A compact globular cluster half way
between " and p Scorpii ; looks like a nebula in small
telescopes.

The

International Ornithological
Congress.

The fourth meeting of the International Ornithological
Conf^ress, under the Presidency of Dr. R. Bowdler Sharpe,
will take place in June at the Imperial Institnte, South
Kensington. H.K.H. the Prince of Wale?, K.G., has graciously
accepted the post of Patron. The General Committee
contains the names of many of the best- known ornithologists
throughout the world who are likely to be able to attend the
meeting.

The first meeting of the Congress will be held on Monday,
June 12, at q p.m., when there will be an informal reception
at the Imperial Institute. A General Meeting will take place
next day at 10 a.m., and the five Sections (Systematic Orni-
thology, Migration, Biology, Economic Ornithology, and
Aviculture) will assemble at 3 p.m. on that day. The Sections
will meet again at 10 a.m. and 3 p.m. on Wednesday, June 14,
and in the evening of that day there will be a conversazione
at the Natural History Museum. Thursday, June 15, will
be devoted to an excursion to the Zoological Museum at
Tring, where the Members will be the guests of the Hon.
Walter Rothschild, M.P. On Friday, June 19, there will
be a General Meeting of the Congress at 10 a.m. In the
afternoon the Lord Mayor of London will receive the orni-
thologists at the Mansion House, and in the evening the
British Ornithologists' Union will entertain them at dinner.
On Saturday, June 17, the Sections will meet in the morning
(10 a.m.), and the concluding General Meeting w.ll take place
in the afternoon of the same day.

141

Koomledge & Seientifie Neuis

A MONTHLY JOURNAL OF SCIENCE.

Conducted by MAJOR B. BADEN-POWELL and E. S. GREW, M.A.

Vol. II. No. 7.

[NEW SERIES.]

JULY, 1905.

SIXPENCE.

CONTENTS. See Page VIL

Ovir StelloLr Universe.

Bv T. E. Heath.

It is related by Campbell that Sir William Herschel
told him he had observed stars the light of which
must take two million years to reach thi.s earth. Did
Herschel grasp what this meant? It is supposed his
reflector could show stars to the 15th magnitude; if so,
he might have seen a star the light of which had been
travelling for two million years, provided it gave
438,000 times as much light as our Sun.

Professor Seeliger thinks our Stellar Universe is in
shape like a thick lens, and estimates the nearest parts
of the Milky Way are about 4,400 light-years distant,
and the most remote about 9,700. Other astronomers
appear to have very vague ideas as to its limits. Some
estimate its probable radius at from 10,000 to 30,000
light-years. Few seem to have checked their con-
clusions by considering what the sun-power of stars at
the supposed boundary would be.

I have drawn a section of our Stellar Universe of the
shape which Professor Seeliger's statistics of stellar
density seem to require, but I have not adopted his
dimensions. The maximum size I think probable in
light-years is indicated by circles struck from what ap-
pears to be the most likely present position of the Sun.
The drawing pretends to no accuracy of stellar distribu-
tion, save that I have, very roughly, made the stars
congregate about the Galactic Zone and the nebulfe
about its poles. So far astronomers are agreed, but
for the rest some think the stars thin out, others that
they get more numerous towards the boundary.
Probably the Milky Way is very much what it appears
to be, a congregation of stars, clustering here,
separating there; irregular forms and masses such as
we see in Spiral Nebulfe; nearer to us in parts, more
distant elsewhere, but lying generally in a great circle
round us. There seems to be no reason for thinking
the thickness is greater than the lateral extension; in-
deed, the rifts and openings give the opposite im-
pression.

I remember how thirty or forty years ago most of
the stars were supposed to be almost infinitelv distant,
but yet revolved in some mysterious way round Alcyone.
No one did more by star-charting and lecturing to
change the general opinion about the \'isible Universe
than Richard Proctor. His equal surface chart of
324,000 stars to about gth magnitude shows the chief
features of the Milky Way and even the wonderful
complexity of its interior structure. He savs it has on

it 1,115 lucid stars, and it covers 9 per cent, of the sky;
the gaps in the Milky Way cover 1.6 per cent, and
have on them only 20 lucid stars, whilst the remaining
89.4 per cent, of the sky has on it 4,715 lucid stars.
He concludes the 640 stars in excess of normal density
which we see upon the Milky Way are actually in it.
Professor Newcomb has shown that the circle of the
Milky \yay can be found within 5° of its true position
by the clustering of lucid stars alone, and proved that
about 70 per cent, of stars up to 6th magnitude and
about 140 per cent, up to 7th magnitude, which appear
to be on the Milky Way, are in it.

Possibly there are no stars in the Milky Way greater
than the 3rd or 4th magnitude, and but few of them;
of the 5th there would be more, of the 6th a consider-
able number, and of the 7th and 8th very many
thousands. According to Profe.ssor Kapteyn, in anv
group of 15,000,000 stars, 13J per cent, would be about
one sun-power each, 3I per cent, would be more, and
833 per cent, would be less. If this be true, from what
we know of the probable number of stars of each magni-
tude (see Mr. Gore's estimate, " Knowledge," 1901,
page 178), a star of one sun-power at the Milkv Wav's
average distance would appear about the 12th' or i '^th
magnitude.

Assuming the Sun's magnitude is - 26.4, I worked
out his magnitude at different distances in light-years;
they come thus, at 479, nth magnitude; at 759,' 12th;
at 1,210, 13th; at 1,910, 14th; at 3,020, isth; at 4,790,
i6th; at 7,590, 17th; at 12,100, ^8th: and at 19,100,
19th magnitude.

Now there are very few i8th magnitude stars, and it
is doubtful if there are any 19th, but it will be seen that
if the Sun were removed to Professor Seeliger's esti-
rnated mean distance of the Milky Way (viz., 7,550
light-years), he would be reduced to the 17th magni-
tude. There may be 20 or 30 per cent, of' the Milky
Way stars as small as this, but thev are certainly
nothing like 83 per cent, smaller.

Profes.sor Newcomb writes that " the bluest and
most luminous stars are situate mainly in the regions
of the Milky Way," but apparently he comes to this
conclusion because he thinks the Milkv Way begins
beyond a distance of 1,300 light-years, and considera-
tions based upon proper motions lead him to place
these stars even beyond the sphere of 3,260 light-years

Proctor thought the Milky Way stars are for the
most part small.

It seems not unreasonable to suppose that
tor any considerable group of stars, such as the
Milky Way, we can make the best estimate of probable
distance by assuming that none of them are much more
luminous than the giants of the same class we have
measured, and that they contain a fair proportion of the
stars of all sizes we have discovered in the only space
sphere at all thoroughly surveyed (that of 15 light-years
radius).

14^

KNOWLEDGE & SCIENTIFIC NEWS.

[July. 1905.

In my " Road-Book to the Stars " I asked for correc-
tions and additional data. Mr. Gore kindly sent mc
the paper on the " Relative Brightness of Stars,"
which he communicated (January, 1905) to the Royal
Astronomical Society. In this he only gives stars for
which he thinks the parallaxes are fairly good; those
mcst reliable he marks (*), whereas in my "Road-Book"
I gave all the estimates I could collect. So far as Mr.
Gore's list goes my distances agree with his; I have
now in the list for ist magnitude stars herewith put (*)
to the distances he considers most reliable, and (?)
against those he does not give at all. Otherwise the
light-years remain as in my book. Mr. Gore has taken
the Sun's magnitude as - 26.5, whereas I took if as
- 2(-).^; so that, other things being equal, where he
called the relative brightness of a star 1,000, I should
call its sun-power 1,095.

Mr. O. R. Walkey also has .sent me a long and very
interesting account of his method of getting at the
.\bsiilule Parallaxes for ;ill the ist magnitude and
some other stars. Onlv he himself could do jitsticc to
his method, but I give his absolute parallaxes and sun-
pf)wers. (He takes the .Sun's magnitude as — 26. .4.) If
Canopus is, as he thinks, of 71,8^0 sun-powers, and if
the surface brightness is the same as the .Sun's, the
-Sun might be situate at the centre of Canopus, the
earth would revolve about 22 million miles below its
surface, and we should find it quite unpleasantly hot.

In the following list I have divided the first magni-
tude stars into two classes : the first, Orion, tvpe O,
Sirian, type I, and Procyon, type I-II. The second,
Solar, type II, and .Autarean, type III. Parallaxes ob-
served at the Cape are marked C, at Yale, Y. The
magnitudes arc revised Harvard.

In the Appendix to my " Road-Book to the Stars " I
give all the data as to other magnitudes I could collect,
but they are too few to enable me to work out,
correctly, the average distances and sun-power for each
type and magnitude. ICstimates may, however, be
made from Professor Kapteyn's formula derived from
parallactic motions. Professor Xcwcomb has done this
in his book on the ".Stars," doubling the di.stance
everv two magnitudes, but Mr. O. R. W'alkcy has
corrected his parallaxes bv going carefullv through
Kapteyn's original work. From these corrected
parallaxes I have worked out the distance in light-years
:md the sim-power for each type and magnitude. T/ie
rt'Siif/s, if they can Ix relied upon as averages (not, of
course, for individual stars), are of great importance.

Mag.

I.isht-
Vears.

Type

Sun-
Power

185

333
2j6

247

—

ib7

438
587

lis

«4

f)0

779

—

104 1

—

10
II

1392
1845

21
15

The average sun-power

ha\'e fouiul

to be

."^.1.

,2/.S,(

Type

11.

Light-

.Sun

Years.

Power

—

4.S

loy

—

144

—

2.^

193

—

257

—

1 1

341

4.')7

—

.S-7

6oq

—

812

—

2<)

for the first magnitude we
)()5 for type 1, and 529/397
for type II. I'"ar beyond the second magnitude ! From
the second down the sun-power is halved everv two
magnitudes — tlie further we go the smaller is the average
size/ But in my " New X'iew of the Stars " I show
that in the only space-sphere thoroughly surveyed, the
pcrcciil;i.^i s are as follows: — :?.( of [ to 56 sun-

Type. Masnitude, Parallax

'Rflntivc !

Error.
±

My ■■ Koad.Book.

Mr. VValkey's Kstimates for

Mr. Gore's

Relative 1 ]

Light- Sun- Brightness. Absolute i Light- Sun-

Years. Power. Parallax. , Years. Power

Sirius I - ''58

Canopus Ill - o-!S6

Vega I -j- 0-14

Rigel 0 0-34

Procyon I-II 0-48

Achernar () o'6o

ft Centauri O 0-86

.-Mtair I o'Sg

a Criicis () i'05

Spicn O I '2 1

Foinalhant I rag

oCyKni . . I 133

Kegiiliis . . ( ) 1-34

fl Criicis ( ) I '50

First Class 14 Stars a veraRe o'5o

•370
•000
•082
•000

■334
■043
•030
•232
•050
•000
•130

Y — -012

Y -024
C '000

005

'■■■ S-8

•377

8-64

•010

? 296

21357

—

•006

543

71880

016

397

154 a

139

•090

36-2

127

OIO

•' 367

110250

—

•oo5

543

23800

•015

IO-2

7-6

0-49

•335

973

0-7

•015

? 76

362 a

—

■045

72-4

333

•015

? 108

605

—

•036

90-5

410

■019

■'■■■ 14-2

9-6 0

879

•239

13-6

•019

65-2

183

leo

•044

23"

■020

? 326

38440

—

•010

326

3845

•014

18-9

■133

24'5

•023

? 271

2565

—

•004

815

21520

•020

148

700

642

•031

105

355

■008

? 326

2981

—

•010

326

2944

•02191 -015

3132

8965

a Centanri

Arctiirii

Capell.i

BctelRiiese

Aldebaraii
Pollux .
.•\nlar(~

SL'cond CI. I

. . 11-

i.-i)6

•752

•oto

f. t

r-.,«)

. . 11

0-24

•026

■017

>.ib

ir.480

. . II

0-2I

•079

■021

146

\t m.ix iniiim

' 0-34 1

III

'••■m'

•024

■024

.- 142

933

I -of.

•109

■014

'' 3"-5

1 1

I-2I

•056

■023

? 58

118

III

1-22

•021

■012

? 155

820

148()

757

4'3

I "9

034

95-8

950

087

37-5

128

m axunnin

1047

029

1 12

—

■I If)

28-1

0()(>

49-4

•027

121

533

. 7 .St;ir.s .ivt-r.-i^f;

N.B. Some of my sun-powers i narkeil a) arc slightly altered from Uiose n'ven belore owing lo corrected magnitudes.

July, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

143

t^VLV .stellar ftttiber^e.

2' 5-00

'-y-

21000LY

'• "■'*■•*•'• "J"'.' y^."' .' '*' ',' *•'•* ' I'r'ii''* -'•-**'""/.'■*<;•• ' ' '■ •"<'\»**''' ■'■• N

^ • ." •/•• ••. * 'y.'ot •.;.-•■■•■.'•' v' .• , ''•.:• '^. ." ■. • •• * •«.-•' • •- 'v • / , . ^

.*\ •. «;■• - •,•'.•.',•• ■■-.■•■'■■■'. V..V- •".•.•/.'■: •;■•]'•'■%•'■''.■-■'■ ' .' '- . -* " .♦'■ - '■•/••

A v;a;Av.^-V-;; ^^r:v>1^'''^^'vrr^."-A'^'":'' aV'' '.V.'v''-'- v.v;'.*.''-;..,r

aa: v^ 'ft v'aMs'^;^^^?^^^'': ^^'^ ■ ^9 « ^' ■ •"^'' V<^ '

•A' - f' •■••V-. .H^ . ••*■•" •<*•"•• •:■.•:••-..■•'.»••■!."'=.':■•., -' > .■--'■•A^

v; 'Av^'iA'V ■''"'•■V' A^^'fAiA'- ' "%■••■-• •-5A-r-^''XAi^'*' '
• ^.' "AAAX;.iA.>; '•. • •• , ■.■/!.:.'"**.•.';.,. .'.'•?•.■*

■^Av:^'-*^

^c."jCc oi- Ico ^uC - (J eaA.6

144

KNOWLEDGE A: SCIENTIFIC NEWS.

[JlLV, 1905.

powers, 29 averaging 0.23 sun-powers, 19 averaging
.034 sun-powers, and no less than 28 averaging only
.005 sun-powers. The majority arc dwarfs : it i'-
quite as necessary to provide for dwarfs as for giants
in the Milky Way, but there appear to be very few
stars of less than the 17th magnitude ! The highest
authority on this point, the late Dr. Isaac Roberts,
writing in "Knowledge" (1901, page 11) about a
photograph of the Milky Way, which shows stars down
to the 17th magnitude, says, " The evidence of photo-
graphs stroni;ly indicates that those vacant places
which appear after exposures of 7 to 12 hours are
really void of stars, because exposures of only 90
minutes show the same stars down to the faintest
magnitudes." His remarks should be read in cxlensa,
as they are more conclusive than thus condensed.

To enable my readers to weigh for themselves the
value of the evidence given here, in my first article and
in my " Ivoad-Book," 1 worked out a table which gi\es
the sun-power of stars of different magnitudes at differ-
ent distances. I think it comprehends all the .Milky
Way stars, but it can be readily extended up or down,
or right or left, e.g., 3rd m;ignitude, at 1,000 light-
years =6,800 sun powers; or 6th magnitude at ion
light-years = 4.37 sun-powers.

From the evidence produced, my readers can judge
as well as I — some better — what are the probable
dimensions of our Stellar Universe. The first magni-
tude stars are exceptionally large, and if they only are
considered, and if Mr. Walkey's estimates be correct,
we might allow a radius of about 5,000 light-years for
the Milky Way, but if 80 per cent, of the stars are
smaller than the .Sun, the radius would not be more
than about 1,500 light-years. I have assumed in my
drawing the truth lies between these extremes. I
claim to be no aiithirity in such matters, but seek onl\
to illustrate by my diagrams and stereograms such
data as I can collect, so that anyone c;m see what they
mean. The scale I discovered, which, taking the -Sun's
mean distance as one inch, makes the distance travelled
by light in one year one mile, is, I find, to most people,
a real help. Objects in space of three dimensions can
be drawn without distortion as well upon a flat surface
as upon a sphere. The excellent maps now being pub-
lished in " Knowledc.e " appear to have no distortion
if they are viewed with a lens so that the eye is 5^
inches above the centre. It is greatly to be desired
that some owner of a clock-driven telescope would
take and publish a set of lantern slide star maps (which
could be enlarged as required), using a stigmatic lens of

L.Y.

Sun-powers of

Stars at Different Distances.

Magni-

L.Y.

1 L.Y.

L.Y.

I..Y.

Star.

1,000

i.Soo

2,000

2,500

3.000
S.P.

3.S0O

4,000

S,c^

6,000

7,000

7.500

8,000

9,000

S.P.

''s.pT

S.P.

2,700

6,080

10,800

16,900

24.300

33.100

43.300

67,600

97.300

132.500

152,900

172,800

218,700

1,140

2,550

4.550

7,060

10,200

13.900

18,200

28,200

40,800

55.700

64,000

76,900

91,800

437

980

1.750

2,720

3.920

5.330

7,000

io,goo

15.700

21,200

24,500

28,000

35.300

«75

392

700

i,ogo

'.570

2,130

2,800

4.360

6,280

8,540

9,900

11,200

14,100

•54

272

428

615

840

1,090

1,710

2,460

3.560

3.840

4,360

5.530

108

i6g

243

330

433

676

973

1.325

1.529

1,728

2,187

114

255

45-5

I02

'39

1.82

282

408

557

640

769

gi8

4'4

9-8

175

IO<J

157

212

245

280

353

1-7

3'9

7-0

112

141

1-5

4'3

0-27

0-6

I -08

2-4

4'3

6-8

0-25

o"45

I 02

'•4

1-8

2-8

4-1

5-6

6-4

(J-2

0-04

o-io

017

0-27

0-39

0-7

i-i

2-1

2-4

2-8

3'5

0-02

o'o4

0*07

o-ii

0-16

0-21

0-28

0-44

0-63

0-85

i-o

i-i

■'4

0-007

0015

0-027

0-04

006

0-08

o-ii

0-17

025

0-35

0-38

0-4

0-5

0003

o*oo6

0-0 1 1

0-017

0-024

0033

0-04

0-07

o-io

"■'^M

0-15

0-17

[0-2

Dr. F'laston in an interesting article (" Knowledge,"
1903, page 154) gives a sample of the Milky Way
(area Man part of sky). He has estimated magnitudes
(from 5.2 to 14) of the 1,761 stars shown therein.

To help our judgment I worked out the sun-powers
ff)r these stars, upon the supposition they are either
1,500, or 3,000, or 7,500 light-years distant. They
come out as follows : —

verage

1500

3000

7500

Mag.

L.Y.

5-2 — I Star

2075 S.P. .

. 8300 S.P.

.. 52,900 S.P

7-8- 1 „

225 „ .

. 900 „

- 5.730 „

8-3- 6 ..

120 „

480 „

3,060 „

8-8 - 6 „

80 „ .

320 ,.

2,040 „

93- >7 ..

51 .. •

205 „

1,300 „

g-8- 42 „

33 .. •

132 ..

S40 „

10-3— 61 „

20 „

81 ,.

516 ,.

ic-8 — 103 „

12-5 ., .

50 „

3'8 ..

"•3 -'35 ..

8 „ ,

32 ,.

204 „

11-8-134 „

5 .. •

20 „

130 „

12-3 -141 ..

3-25 .. •

'3 ..

84 ,.

12-8 - 188 „

2 „

8 „

51 ..

13-3 - 229 „

1-25 „ .

5 »

32 ..

13-8 - 697 „

075 ..

3 ..

20 „

3I inches focus and short exposure, so ris not to go
much below the 6th magnitude.

In my first article I suggested a model which would
show the Sun and stars of estimated parallax shining
with proportionate luminosities. I have constructed
such a model more efhcicntly than I had hoped, and
upon convenient tlal surfaces, in the six large stereo-
grams I recently exhibited in London. 1 may even say
that when 1 took the members of three learned societies
many hundred billion miles out into space and showed
them the .Sun and stars shining in their prr.pcr colours,
with their relative luminosities and hanging in space at
their eslimalcd dislaiircs, I broke through ihe crvstal-
line vault which iias so long imprisoned even those who
know it is but an illusir)n.

Notice to Readers.

We beg to remind regular subscribers that the Special Number,
to be published on July 15th, will run concurrently with the
usual numbers, the paging being continuous, and the matter
will be included in the index for the year.

July, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

145

A New Process for
Welding Aluminium.

The Cowper-Coles process for welding aluminium re-
quires no flux, and does not necessitate the hammering
of the joint when in the semi-fluid state. The process
is especially suitable for wire rods and tubes and other
drawn or rolled sections, and consists in placing the
parts to be welded, after being faced off square, in a
machine (illustration No. i), fitted with clamping

Cowper-Colcs's Machine for Welding Aluminium.

.-1, Serten; B. Aluminium Bo els ; C, Lamp; D, Levers for applying prcsiuve :
E, Pump; Fj Water Remivoir.

screws, which are capable of moving horizontally on
guides; the movement of the clamping sciews is con-
trolled by the levers D. The aluminium to be welded
is heated by means of an ordinary benzine lamp. As
soon as the rods have arrived at the necessary tempera-
ture, slight pressure is applied to the levers D, which
causes the aluminium rods to unite, and a ring of metal
is squeezed out, as shown in illustration No. 2. This

Joint after Welding.

ring is largelv composed of aluminium oxide, and acts
as an insulating and supporting collar, the molten metal
being retained within this collar. The weld is then
instantaneously quenched by turning a handle attached
to the screen A, which allows water, under pressure,

to be projected on to the joint from the reservoir F.
The same handle which turns the water on, places the
screen A in front of the heating flame. The water
pressure is maintained by air supplied by the hand
pump E. The rod is finally removed from the machine
and the collar filed off, when it will be found that the
joint is as strong as the rest of the metal. An oxygen-
hydrogen flame or ordinary gas with or without air can
be substituted for the benzine lamp. The process is a
simple one, and can be worked by any unskilled work-
man.

Illustration No. 3 clearly shows the molten aluminium
supported by a pipe or case of aluminium oxide,
the case havincr been pricked with a steel point
to allow some of the molten metal to flow out.

The following table gives the result of tests for
tensile strength on twelve consecutive welds (not
picked specimens) made by the process just
described. The fractures occurred at a con-

siderable distance from the weld, showing that the
metal has not deteriorated at the weld. In the twelve
tests referred to, not one specimen broke through the
welded portion.

Pp-

Extension.

On Original Area.

duo-

Elastic Limil

area

2 in

(Yield Point).

stress.

at
frac-

on
4 in.

Remarks.

sions.

Square
inches.

ture.

Pounds.

Tons

Pounds. Tons

Per
cent.

Per square in.

Diam.

( Hroke outside

0-249

0-0487

7-4

11491

5-13

9-04

Idaluiii points.

0-24S

0-0483

7'4

•13

8803

T93

22265

9-94

0-254

0-0507

7'5

1 1043

4 93

19868

8-87

0-252

7'4

14358

0-41

16150

721

7'7

. 21996

9-82

21996

9-S2

7-6

14134

b-3I

19622

0-0491

7-7

14134

b.31

14134

6-31

7'P

15030

6-71

24304

10-B5

7-«

14940

b-67

20361

9-09

0-0503

7 7

10236

4-'i7

19152

8-55

7-7

12320

5-io

20070

0-247

0-0479

8422

3-75

■

18704

8-35

146

KNOWLEDGE & SCIENTIFIC NEWS.

(July, 1905.

The Nature of Life.

By Geoffrey Martix, B.Sc. (Lond.).

II.

Now the temperature and pressure on the world's
surface have not always remained exactly the same as
they are at present. Indeed, it is probable that the further
we go back, the higher was the temperature conditions
which held upon the world's surface. Probably, in-
deed, at the earliest times, the world's surface was a
white hot fluid mass surrounded by vast masses of
vapour. Consequently, in very early times, if living
matter existed, its structure must have been quite
different to that which it has at present. And the
further we go back, the greater must have been the
difference between the structure it possessed then and
the structure it possesses now. For at ordinary tem-
peratures and pressures, living matter contained the
exact quantities of the necessary elements (namely,
cartx)n. hydrogen, nitrogen, oxygen, sulphur, and
phosphorus) to make its critical temperature of de-
composition coincide with the conditions which hold
upon the earth. .And as the temperature and pressure
of the world altered, the relative quantities of these ele-
ments entering into the structure of living matter would
also have to alter in order to make its critical tempera-
ture and pressure coincide with the new temperatures
and pressures.

The higher the temperature and pressure, in general,
the greater would be the tendency to let heavier and
less volatile elements enter into its structure, and at the
highest temperatures and pressures, living matter, if
it existed at all, must have been composed out of alto-
gether different elements to those which at the present
time enter into its structure.

I would, in fact, suggest that the structure of living
matter has, like most other things, undergone a con-
tinuous process of evolution (and is still undergoing it)
with the changing extern.il conditions, and that at the
time when the earth was a white hot fluid sea, life still
existed in a form quite different to that which it now
nossesses; that the chief elements entering into its
structure were at that time heavy non-metallic elements,
such as silicon, sulphur, phosphorus, and oxygen;
and that as the world gr.iduallv cooled, the heavier
clements were gradually eliminated and the lighter ele-
ments took their place by a natural process of circula-
tion, until finally the composition of living matter
assumed its present one.

N'ow is there any element which could play at high
temperatures in living matter the part plaved therein
at ordinary temperatures by carbon? .Silicon is such
an element. .Silicon, like carbon, possesses a high and
constant valency, has a very considerable capacity for
self-combination, and is capable of giving rise to an
enormous number of very complex bodies— the silicates
and their derivatives— which well vie in complexity
with the most intricate carbon compounds. The
fundamental difference between the two sets of com-
pounds is essentially one of temperature, the carbon
compounds being at ordinary temperatures much nearer
thf^ir mcltmg and decomposing points than the silicates.

Seemg that the temperature whereat carbon gives
rise to protoplasm is at a temperature at whirh most of
Its compounds with hydrogen, oxygen, and nitrogen
are (probably on account of thr-ir instability; spp

the author's work, " Researches on the Affinities of
the Elements," pp. 120-123) '" a fluid or semi-fluid
state, we should expect that the most suitable tempera-
ture for silicon to give rise to an unstable compound
would be the temperature whereat the silicates are un-
stable and, therefore, in a fluid or semi-fluid state —
that is to say, at a white heat. Have we any evidence
to support the view that living matter did not start
originally with carbon, hydrogen, oxygen, and nitrogen
as its fundamental elements, but started with elements
of far higher atomic weights, such as silicon, phos-
phorus, sulpluir, ;in(l oxygen, of which only \esliges
now remain in the protoplasm? In this connection it
must be remembered that our evidence could be only
indirect. For such life might have flourished to an
enormous extent in the molten sea of siliceous matter
which covered the earth's surface in bygone ages, and
yet have left no traces of its existence behind; for when
such forms of life died, their bodies would but blend
again into the molten rock, in the same way that a
jelly-fish dies and blends again into the ocean of salt
water, without leaving a vestige behind to show that
it has been and gone. Except under exceptional cir-
cumstances, organised matter, when dead, very quickly
disintegrates.

However, many remarkable siliceous minerals exist —
for example, the mineral " Asbestus " or mountain
leather — whose peculiar fibre-like structure may be due
to its previous organic nature in bygone ages. Again,
in some of the most rudimentary forms of organised
existence — for examples, the diatoms and sponges —
silica still remains in considerable quantities.

Now it is clear that in consequence of the progressive
cooling of the earth, the range of temperature at which
silicon possesses the capacity for forming the central
element of living matter would soon be passed, and
hence its complexes would solidify out into stable
masses, thus causing all life to cease.

But if carbon entered more and more fully into the
composition of living matter, and the silicon as steadily
solidified out as the cooling continued, the critical tem-
perature of decomposition (or temperature whereat life
is possible) would become progressively lower in pro-
portion as the amount of carbon in the organism in-
creased, and hence the cooling of the surrounding
medium, and the alteration in the living temperature
of the organism, would proceed together and keep pace
— the temperature of the organism lagging slightly be-
hind the falling temperature of the surrounding medium
— -as it actually does now in world life. The silicon
age would thus blend imperceptibly into the carbon age,
and when the modern thermal conditions were attained,
the carbon would long since have replaced completely
the silicon in living matter, and the last era of organic
existence would have been entered upon.. I believe
that silicon once completely replaced carbon in matter
living at a white heat, but that at ordinary temper.i-
tures it has been completely replaced by carbon, and
remains now merely in certain forms of life as an in-
active sediment solely because it can be put to a useful
purpose by imparting rigidity to the frame. In cases
where it serves no such purpose it has been already
completely eliminated; for example, in animal proto-
plasm only minute traces remain; on the other hand, in
grasses and diatoms very large quantities of silicon
still exist.

Just as water, the mother liquid in which modern
protoplasm first throve, enters to a very large extent
into its composition; so also we should export thnt

July, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

147

silica of the molten earthy sea would also enter very
largely into the composition of the life which flourished
at the time when the earth's surface was a red or white
hot mass of molten rock. Let me now quote some
other facts which make it probable that as the thermal
conditions of the earth altered there was a correspond-
ing alteration in the composition of living matter, the
denser and less volatile elements steadily solidifying
out and their places being filled by analogous lighter
and more volatile elements.

Albumen contains a small quantity of loosely-bound
sulphur which does not appear to be a very intimate
constituent of it. No one knows the function of this
sulphur; according to my theorj' it is simply lingering
on, the relics of a time when it almost entirely replaced
oxygen in the organism. As the temperature of the
living matter fell, the sulphur was superseded by the
lighter and more volatile oxygen, and consequently
the sulphur which remains is merely an inert mass in
the process of elimination, separating out on account
of its heaviness, in exactly the same way I have sup-
posed silicon to have separated out in previous ages.

Much the same applies to phosphorus in the tissues
of the brain and nerves. It has almost entirely been
replaced by the lighter and more mobile nitrogen.
The small amount of phosphorus remains mainlv be-
cause it can perform functions of which nitrogen is
incapable. Not only is this so, but traces of a still
heavier member of the same group of elements — arsenic
— have been recently found in certain animals, where it
partially replaces the phosphorus in nucleinic matter.*

In these cases, then, we have a whole chain of chemi-
cal analogous elements replacing each other in continu-
ally decreasing amounts as thev increase in heaviness.
Thus : —

(■Nitrogen (at wgt. 74) abundant.

J Phosphorus (at wgt. 31) less abundant.

I Arsenic (at wgt. 75) minute traces.

(Oxygen (at wgt. i6) abundant.

J Sulphur (at wgt. 32) less abundant.

(Selenion (at wgt. 79) minute traces, if at all.

(Carbon (at wgt. 12) abundant.
1 Silicon (at wgi. 28) traces.

These facts favour our supposition that the presence
in protoplasm of elements having a high atomic weight
are the links which connect the gradually-evolved
protoplasm of to-day with the molten minerals of the
past. It is very probable, I think, that in many cases
formerly abundant elements have ceased to perform
any vital function and solely remain as witnesses to the
process of evolution, much as the gills on the neck of
an embryonic babe bear witness to the aqueous origin
of its ancestors. In some cases, perhaps, they are
retained on account of the fact that they can be put to
useful purposes by being substituted for their lighter
chemical analogues, in order to modify the functioning
of certain definite organs by reason of certain specific
needs. Such would be selenion in place of sulphur;
negative sulphur substituted for oxvgen; Cu, Zn, or
Mn replacing iron; P, As, or even Va itself playing the
part of nitrogen in the atomic complexes which make
up protoplasm. The whole problem of the secretion of
mineral matter by living beings is ably explained by
supposing the mobile protoplasm of to-day evolved in a
continuous matter from the molten minerals of the past.

By adopting this conception the range of world life
would widen magnificently out from the few billion

' Gautier, Chem. Nra's, March 23rd, 1900.

years of Lord Kelvin to countless billions of years,
when the world was a white hot globe and its surface
a sea of rolling fire. From first principles, indeed, it
is very improbable that life could exist only within such
narrow limits of temperature and pressure such as are
at present prevalent upon the earth. Out of the almost
infinite time which has passed before the world cooled
to its present state, and the ages that still must run ere
the world reaches the absolute zero of temperature, is
it to be imagined that during an only infinitesimal por-
tion of this time could organised life exist? To assume
this is to place oneself in the position of those early
astronomers who held that the sun and stars and the
infinite universe itself revolved about the earth as
centre.

Again, are we to assume that out of an unknown, but
probably enormous, number of elements, only some four
namely, carbon, hydrogen, nitrogen, and oxygen, are
capable of producing vital matter? When we study
the properties of these four elements and compare them
w'ith those of other known elements we find that there
is absolutely nothing which inherently distinguishes
them from the other elements. Every property
possessed by them is shared to a greater or less extent
by the other elements also. Why, then, should we
imagine that only these four elemants can give rise to
living matter? Why they enter so largely into the
constitution of living matter upon this earth is probably
a pure accident of temperature and pressure. They
merely happen to possess the proper degree of volatility
and the capacity for exerting chemical forces of the
requisite intensity, which make them somewhat more
adapted than the other elements to enter into the con-
stitution of living matter under those particular tem-
perature and pressure conditions which hold upon the
earth. But vi'e know that the chemical properties ex-
hibited bv an element alter very considerably with the
temperature and pressure conditions under which it is
viewed. Indeed, it has been suggested* that by alter-
ing the external conditions upon which we view an
element, we can make it assume in succession the vari-
ous chemical conditions which the various other ele-
ments find themselves in at ordinary temperatures and
pressures. If this be so, it is ditficult to avoid the infer-
ence that under other external conditions, other ele-
ments would so change their nature as to become
capable of entering into the structure of living matter,
although under ordinary temperatures and pressures
they are quite incapable of so doing.

Sweeping through space are myriads of vast planets,
countless swarms of mighty white hot globes and
dark suns, whose physical conditions differ utterly from
those which hold sway upon the earth. Surely these
are not devoid of life? Nay, on such mighty globes
life exists on a far grander scale of creation than any-
thing that we can conceive of; life utterly different in
form and motion to that which exists on our puny
earth, and even composed, perhaps, out of entirely
different elements to those which compose the living
matter of world life.

Life is old, old as the universe itself. It has always
existed generally throughout the universe in some form
or other, and always will exist, no matter what happens
to our little earth. The protoplasm of the earth is but
the product of evolution of untold ajons of ages,
coming down to us in an unbroken line from ages when
the world was a vast liquid globe of white hot material.

'Chemical News, Oct. 14th, 1904. See also the author's work
,. Researches on the Affinities of the Elements," p.p. 206-225.

KNOWLEDGE & SCIENTIFIC NEWS.

fJlLY, 1905.

All the elements have circulated in succession through
its structure, and then passed out again. First at the
highest temperatures came the heaviest and least vola-
tile elements, then as the temperature fell they gradu-
ally were eliminated and their places were filled by
analogous lighter and more volatile elements, until at
last living matter assumed its present composition.
But this replacement of denser by lighter elements is
now almost complete, for the principal elements already
present in living matter are carbon, nitrogen, oxygen,
and hydrogen. ^ And these it w ill be noticed are among
the very lightest non-metallic elements which, so far
as we know, exist. No lighter elements, then, can
replace those already present in the organism, and,
therefore, there can be no further very great alterations
in the temperature of living matter in the coming ages;
but the world is still cooling. Consequently, age by
an-e, century by century, the contrast between the tem-
perature of living matter and the temperature of the
surrounding medium is becoming more and more ac-
centuated, " and the difficulty of maintaining life is
steadilv increasing. I think, therefore, that .so far as
the surface of this earth is concerned, organic life is
entering into its last stage of evolution.

University of Kiel, May. 1005

A Ra^ised Beacch in
Anglesey.

By G. H. I^.KVAN, F.R.S.

In the island of .Anglesey, alxjut three miles north-east
of Beauniaiis and about one mile from Penmon, I came
across an interesting example of a raised beach, of

are all common species, apparently. Many of the
specimens are, however, more or less worn and d'S-
coloured by iron oxide. Tlie boulder clay itself is of a
dark purple colour.

The existence of these raised beaches is interesting
as showing the changes which have taken place in the
level of tlic earth. The section shown in the first photo-

Fij(. I.— Section ol boulder Clay near Penman. AnKlt'.<ey
beach of sand overlyinf; It.

which the accompanying photographs may give some
idea. It is situated in a small bay, and rests on the
top of a deposit of boulder clay at a height of some six
feet above the existing beach. At the eastern extremity
a stratum of broken shells occurs in the sand in several
places, and is well shown in the second of the two
photographs. In this shell deposit foraminifera arc
frequent; these are of large size and are mostly similar
to the recent forms occurring on the sands lx;low. They

nf the Raised Bsach sh<
<;hcll Deposit.

vhite streaks of

graph h<is been exposed bv the action of the sea, which
at high tide reaches tlie foot of the bonkler clay which
it has exposed, and the identity of the foraminifera in
the shell deposit with the recent ones in the sand below
suggests that the changes of level have occurred in com-
paratively recent times.

COR. DESPONDENCE.

The Action of Wood on Photographic
Plates.

To THE Editors of " Knowlicix;i:."

Deak Sirs, — I have read with much interest the article on
the action of woods on photoRraphic plates in the dark, which
appears in this month's " Knowi.kdgi;," and, believins the
action due to the actual radio-activity of the wood, 1 was of
opinion that an emanation should I)e visible under proper con-
ditions, as is the ca.sc with tlie recognised radio-active sub-
stances—the intensity of the action of any radio-active
substance appearing to depend on the /nv/ncnn' of the atomic
disintegration rather than on the intensity of disintegration of
each individual atom. Hy using a very sensitive screen, I
have distinctly observed a homhardment from a piece of wood
fl used white frctwood), each individual scintillation being
about as bright as any I have observed from L'ranium, I'itcli-
blende, Polonium, or even Kadiuni, the great difference being
that, whereas from such substances the emanations pour forth
in such numbers as to light up the screen with countless
flashes, in the case of the wood they came singly or now and
again in twos and threes, with a considerable interval between
each. This would seem to account for the comparatively
feeble and slow action of woods, as it would of necessity take
considerable time before the cumulative effect would become
evident.

I shall be very glad to know if scintillations from wood have
been observed before.

\'ours very truly,

Charles W. Raffetv.

Strathmore, Streafham Common, S.W.
June 8tb, 1905.

July, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

149

Electrotyping.

By Dr. F. Mollwo Perkin.

In the article on electrotyping in the January number
of " Knowledge " various methods for reproducing
medallions, coins, &c., were given. But this does not
by any means exhaust the possibilities of electrolytic
reproduction. Statuettes, and even large statues, can
be, and often are, copied in a similar manner. Thus
a statue of the Earl of Eglinton, which is 13 J feet
high, was reproduced by Messrs. Elkington and Co.,
the weight of the electrolytic copper being about two
tons. The reproduction of a statue, as may readily be
imagined, is not by any means an easy or simple pro-
ceeding.

Generally speaking, the original is first formed in
plaster of Paris. The plaster cast is then thoroughly
saturated with boiled linseed oil or with melted paraffin
wax. After standing for some time to allow the oil
or wax to thoroughly set and harden, the entire surface
is brushed over with graphite, and is then polished, so
as to form a homogeneous conducting surface.

The model so prepared has conducting wires fixed
against different portions of the surface, so that the
electric current may be evenly distributed, and is then
connected with the negative pole of the source of
current and placed in a copper sulphate bath. When
a coating of sufficient thickness has been obtained—
about i: or more of an inch — the figure is removed from
the bath and carefully washed. It is now necessary
to remove the plaster form, and this is done bv cutting
the deposited copper in appropriate parts, so that the
copper shell can be removed in portions. The fewer
cuts that require to be made, the better, so that the
portions of shell may be as large as possible.

The parts or " formes " of the copper shell so ob-
tained represent the negatives or moulds upon which
the positive is to be deposited. The inner portion of
the formes are exposed to the fumes of sulphuretted
hydrogen or are washed with a dilute solution of
potassium sulphide. By this means the copper becomes
coated with a thin film of copper sulphide, which is
conducting, but upon which the copper to be deposited
will not adhere. The outer surfaces of the mould are
varnished to render them non-conducting. The vari-
ous portions of the shell are then placed in a coppering
bath and the current passed. When the deposited
copper reaches a thickness of about J of an inch, thev
are removed from the bath and well washed. The
freshly-deposited shell is now carefully stripped off
from the outer shell and the different parts joined to-
gether.

Stereotyping. — The most important application of
electrotyping is in the preparation of stereotypes.
When a large number of copies of a book require to
be run off, and in order not to keep too large a quantity
of type set up, a copy is reproduced in stereotype.
The following description of the procedure adopted is
the principle of the process, although individual firms
adopt methods which vary in detail. Suppose it is re-
quired to produce a stereotype of a page of a book.
The set-up type is placed face downwards upon a wax
plate (gutta compositions are very often employed)
cast upon a sheet of lead. It is then placed under an
hydraulic press, by which means a perfect impression of
the type is obtained in the wax. The type is then re-
moved from the wax impression, which is then

graphited, being generally first slightly warmed to
render it just soft, so that it takes the graphite more
thoroughly. Of course, it must not be sufficiently
heated to blur the sharp edge of the impression.
Pieces of stout brass wire are now pushed through the
wax imtil they come in contact with the graphite at
variou.^ parts where they will not injure the impression
of the type. These pieces of wire are to make electrical
contact so that when the current is passed it may be
evenly distributed.

The prepared impression is now placed in the copper-
ing bath and subjected to a fairly low current until the
whole of it has obtained a complete coating of copper.
It is now either left in this bath until a sufficiently thick
shell has been produced or else it is taken out and
placed in the quick-depositing bath, where a much
higher current density is employed and the electrolyte
is kept well agitated by blowing air through it. In the
quick bath the shell may be finished in an hour or two,
but may take a day or two in the slower bath (some-
times it is placed directly in the quick bath without
being first treated in the slower one). As soon as a
sufficiently thick deposit of copper has been obtained, it
is removed from the bath, and if the stereo is small the
wax is stripped away by hand. But in cases where the
shell is of any considerable size, and, therefore, liable
to be damaged, the wax is usually melted out with hot
water or by blowing on steam. The galvano is now
thoroughly cleansed from adhering wax and graphite
by brushing it in hot water and with caustic soda or
dilute hydrochloric acid. The next process is to back
up the copper, because as the shell is less than one
millimetre thick it is much too thin and fragile to use
ff)r printing purposes. But before the backing up
metal, which usually consists of lead containing about
6 per cent, of antimony to harden it, is poured in, the
shell must be tinned, otherwise the lead will not adhere.
A very satisfactory way to do this is to first brush the
inside of the shell with some soldering fluid, then place
the shell face downwards upon a flat iron plate and
float the iron plate upon a bath of molten metal slightly
hotter than the melting point of tin. As soon as the
copper shell has become properly heated, powdered tin
is sifted over it, care being taken to give it a perfectly
homogeneous coat. The tin melts and alloys with the
copper, and now the lead can be poured in and it in
turn alloys with the tin. After cooling and machining
the edges and planing off the excess of lead, the stereo
is ready for use.

Facing stereotypes. — When the copper stereo has been
used for some time, owing to the copper being a soft
metal, there is a tendency for the sharpness of the im-
pression to become blurred; furthermore, certain print-
ing inks, such, e.g., as red ink, which contains Ver-
million— sulphide of mercury — act upon the copper and
unite with it. In order to get over these difficulties
the stereotypes are very often " steel " or nickel faced.
The term steel facing is not quite correct, but it has
been the custom to call iron when electrolytically de-
posited steel, because, although its hardness is not due
to its carbon contents, yet it has very much the pro-
perties of steel. It is more usual to employ iron as a
facing rather than nickel, because when used for a
considerable time even iron and nickel facings wear off.
It is then necessary to reface, but before this can be
done it is essential that all of the original facing should
be removed. The iron facing is very readily removed
with dilute sulphuric acid, which has practically no
action on the copper, but nickel is extremely difficult to

150

KNOWLEDGE & SCIENTIFIC NEWS.

[July, 1905.

dissolve, and the copper is very likely to be damaged
at the same time. In order to steel face an electrotype,
the surface is thoroughly cleansed from all traces of
grease and made the cathode in an iron bath; a typical
solution is one consisting of 100 grm. of ammonium
chloride and 1J5 grm. iron sulphate, or 150 grm. iron
ammonium sulphate in one litre of water. Generally
a high current density is employed for one or two
minutes, after which a current of 0.4 ampere to the
square decimetre is employed for about five or 10
minutes, when the stereo is removed and carefully
washed and dried. Nickel facing is done in the same
manner, a nickel bath being employed in place of the
iron bath, and the stereo left in for from seven to to
minutes.

Reproduction of Gramophone Records. — .As an illustra-
tion of the extreme accuracy of the impressions ob-
tained by electrolytic means, the reproduction of gramo-
phone records might be mentioned. As is well-known,
the original gramophone record is made on a wax or
composition cylinder, the mechanism of the instru-
ment causing impressions of various degrees of fine-
ness to be made upon the cylinder, the thickness de-
pending upon the tone and pitch of the sound to be
reproduced. Now, of course, the least fault or un-
evenness in the reproduction would completely ruin the
record. In reproducing a record in copper the wax
cylinder is carefully graphited and then, after being
connected by means of conducting wires with the nega-
tive pcle of the source of current, placed in a rapid de-
positing bath, where it is left for from 70 to 80 hours,
a current of from three to four amperes per square
decimetre being employed. By this means a good
thick negative is obtained which can be used for pro-
ducing duplicate copies of the original voice.

Dentistry. — Electrotyping is also employed in
dentistry for producing mouth plates, &c. A model
of the part of the mouth for which a plate is required is
taken in wax and a plaster cast obtained from the wax
model. The .plaster cast is then prepared as already
described, and placed in a silver bath, a silver electro-
type being prepared; when the silver deposit is suffi-
ciently heavy the model is placed in a gold bath and a
heavy coating of gold deposited upon it. Drs. Pfan-
hauser and Hillischcr have also experimented success-
fully with pure nickel in place of silver or gold.

Deposition upon Flowers, &e. — I will conclude this
article by describing an interesting and artistic method
for coating plants, leaves, or even insects with metallic
deposits. A flower or leaf will not, under ordinary
circumstances, conduct the electric current, therefore
it is not possible to coat it with metal. It is, however,
possible to render the surface conducting by chemical
means in such a manner that the structure of the leaf
is not spoilt. If a leaf is dipped into an ammoniacal
solution of a silver salt and then exposed to the fumes
of phosphorus, the phosphorus reduces the silver salt,
and the whole surface becomes coated with a very thin
film of metallic silver. The surface of the leaf is now
conducting, and if a wire is fastened to the stalk and
the leaf placed in a copper-plating bath, a coating of
copper of any desired thickness can be deposited upon
the leaf. \ better method is to dip the leaf or flower
into an alcoholic solution of silver nitrate and to then,
after draining off the excess of the solution, exoo.se to
the action of sulphuretted hydrogen gas. By this
means a thin and homogeneous film of silver sulphide —
which will conduct the electric nirrtnt— is obtained.
The leaf is now placed in the depositing bath and coated

with copper or silver as the case may be. If the opera-
tion is carefully carried out with a very low current
and only a thin coating of metal deposited, all the vems
and markings of the leaf remain. Leaves, flowers,
and even insects, such as beetles or flies, when coated
in this way can be kept for years without withering or
decomposing. Of course, the actual leaf or insect is
not seen, but is covered with a metallic shell which
almost exactly represents the original.

Star Map.— No. 3.

Cetus, Erida.n\is.

The constellations here shown are of no special in-
terest. It may he noticed that there are two boundary
lines dividing Forna.x from Eridanus. The enclosed
portion is included in the latter constellation by Pro-tor
and some others, but,accordingt:omostauthorities(incli:d-
ing Gould) belongs to Fornax, and is lettered accordingly.
The star at the top of the map marked m is included by
Proctor (and B.A.C.) in Aries, but other authorities call
it M Ceti.

" Piscittm (I. h. 56 m. + 2"^ 14.'), a double star of magni-
tudes 3 and 4. Distant 3A".

o Ceti (Mira) (II. h. 14 m. — 3° 23') a remarkable
variable, usually varying from about 3rd magnitude to
9th. Though it has long been known, iiaving been one
of the first variables noted, it is still an enigma. Its
period seems to vary grtall)', but is usually about
331 da)S. In 1779 it was estimated as ist magnitude;
in ib68 it never attained more than 5th magnitude.
Daring the last twelve periods the magnitude at maxi-
mum has varied from 2'5 to 4-7. The spectrum shows
no signs of the star being double, and the variability
is probably due to its own disturbances rather than to
any outside cause.

7 Ceti (II. h. 38 m. -|- 2° 46'), a double star, distant 3i".
One of 3rd magnitude, yellow; other of 6th magnitude, blue.

e Eridani (II. h. 54 m. — 40^ 45')> ^ double star, dis-
tant 8-2". Magnitudes 3* and 5^. This star is supposed
to have dwindled considerably in magnitude, having been
classed as ist magnitude in the time of Ptolemy, though
now considered as 3-06.

With our special number for the British .Association
meeting will be issued Map No. 12 (South Polar Regions),
which should prove of use to those visiting South Africa.
With the August number, Map No. 6 (Leo and Cancer)
will appear, which will show the region around the sun
at the time of the coming eclipse.

The Word "Patent."

To THE EuiTOltS oi- " Knowi.i-.ijoi.."
Sirs, — The word " Patent " is one of those curiosities of the
li^Dglish languaf^e which tend to make it so puzzling to
foreigners, and even to ourselves. Now this word is perhaps
most generally pronounced f'aylcnt, but in the profession it is
more usually referred to as I'altcnt. There is one reason
which I should like to point out in favour of using the former,
and that is the confusion that is sometimes caused in mistak-
ing the latter pronunciation for the word " Pattern." Jones
may say, "That machine is my pattern," and Brown may later
say, " That machine is Jones's patent, I heard him say so him-
self." When shall we take to teaching phonetics?

Vours faithfully,

SnPFLEMENT TO "Knowledqe & acisNTirio Nkws,' July, ItfOli.

MAP No. 3.

MAP No. 5.
Cetus, EridaLiwis.

July, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

151

The MigroLtion of
Flact-Fish.

By J. Travis Jenkins, D.Sc, Ph.D.

At the present time when so much is heard of over-
fishing and the consequent depletion of the fishing
grounds, the question of the movements of sea-fish is
one of considerable practical importance.

The majority of scientific experts agree that round
fish, i.e., fish of the herring and cod type, perform
migratory movements of considerable magnitude, but
as regards flat fish, i.e., plaice, soles, and flounders, the
consensus of opinion is by no means so unanimous.

The International Committee for Investigation of
the Seas, which has quite recently been established, has
taken up, among other problems, the question of the

any given area can be determined by the proportion of
fish recaptured to the total number of marked fish re-
turned to the sea. Since each marked fish is carefully
measured both when it is returned to the sea and when
re-captured, the rate of growth can also be determined.
Plaice seem to withstand the marking operation wonder-
fully well, but soles are far more difficult to deal
with successfully. No doubt other results will be
arrived at, notably the efficacy of closed grounds in
maintaining a reserve of fish and the effect of the
density of fish population on the rate of growth.

The interest and co-operation of the fishermen is
secured by means of a system of rewards payable for
marked fish, the amount depending on the amount of
information as to the locality of re-capture. It is sur-
prising to find how many hands a marked fish will
occasionally pass through before the label is detected.
In one instance a label which was returned showed
unmistakable signs of having been in the frying-pan.

Marked Plaice which travelled 40 miles in 20 days and was then recaptured.

migration of members of the flat fish family or
Pleuronectidae.

This international committee consists of scientific
experts nominated by the Governments of England,
Norway, Sweden, Germany, and Holland, and is sub-
sidised by grants from the respective Governments.

Batches of marked Pleuronectids, chiefly plaice, have
been marked from time to time and then liberated at
various points in the North Sea. The mark used con-
sists of a silver wire, which is threaded through the
body of the fish in the position indicated in the diagram.
To this wire are attached on the under side a bone
button (shown to the left beneatTi the tail of the fish),
and on the upper side a numbered brass label, in the
present instance L. 169. Each fish is carefully
measured and labelled, the whole operation from the
time the fish is removed from the tank to the time it is
replaced taking less than one minute.

It is hoped that by these experiments the amount and
nature of the migration of flat fish will be determined;
and attempts will be made to show the influence of the
environment on migration. The intensity of fishing in

It is yet somewhat premature to discuss the results in
detail, but it may be said that the idea of plaice and
soles being sedentary fish is now exploded. Plaice
have been returned which have travelled iio, 130, and
210 miles respectively. As to rate of growth, an eight-
inch plaice grows on the average from two-and-a-half
to three inches per annum. More detailed reports will
shortly be issued and are awaited by practical fisher-
men and biologists with equal interest.

Scientific Agriculture.

We have received from the Committee of the Lawes
Agricultural Trust a copy of the Directors' report on the
work done at the Rothamsted Experimental Station for
the year ending March 31st, 1905. The well-known
experimental fields are still continued without any
essential change; in addition a new field has been laid
out to test the residual value of various manures in the

KNOWLEDGE & SCIENTIFIC NEWS.

[July, 1905.

second and succeeding- years after their application.
Other experiments deal with calcium cyanamide, the
new manure containingf nitrog-en derived from the
atmosphere, and with the various cuhivations of bac-
teria which have been recently introduced for the inno-
culation of leg^uminous crops, with the view of makinj^
them more elKcient collectors of atmospheric nitrogen.

During the year in question seven papers have been
issued from the Station in the " Transactions of tlic
Chemical Society," the "Journal of .Agricultural
Science," &c., all of which deal with investigations on
the soil, methods of soil analysis, &c. The annual losses
of carbonate of lime in the Rothamsted soil has been
determined, both that due to natural agencies and that
caused by the use of manures. Certain restorative
actions have been investigated which account for the
maintenance of the fertility of many soils which are
almost devoid of lime. .Another of the papers de:Js with
the remarkable accumulations of fertility in certain
plots of land which have been allowed to run wild for
the last twenty years, and have in that time gained
nitrogen to an extent not readily explicable by the
accepted theories.

A considerable list of investigations in progress is
indicated, in which respect the Station receives con-
siderable help from several voluntary workers, e.g., two
Carnegie Research scholars from the University of
Hdinburgh, and other post graduate students from
Oxford and Cambridge are accommodated and provided
with material for investigation, so that the Station, with
its unrivalled opportunities for research, is becoming .i
training ground for experts in agricultural science.

The Lawes Trust Committee continue to find their
income very inadequate to the proper development of
the Station, only donations and subscriptions from
various sources, including £300 from the Goldsmiths'
Company, £50 from the Clothworkcrs' Company, £.^0
from Lord Rothschild. &c., have prevented a serious
deficit on the year's working. Mr. J. F. Mason has also
promised to erect and equip a new laboratory for agri-
cultural bacteriology, which will be the first of its kind
in this country, as a continuance of the experiments
carried on for many years by his father, the late Mr.
James Mason, at Eynsham Hall, Oxon.

RoLdiation. Pressure.

Pkof. J. H. i'owiiNG, I'.R.S., the newly-clectcd
President of the Physical Society, delivered an interest-
ing address before that Society on " Radiation Pres-
sure," of which the ff)llowing is an abstract : —

" A hundred years ago, when the corpuscular theory
held almost universal sway, it would have been easier
to explain the pressure of light than it is to-day, when
it is certain that light is a form of wave-motion. The
means at the disposal of early experimenters were in-
adequate to detect so small a quantity; but if the
eighteenth century philosophers had been able to carry
out the experiments of Lcbedew and of Nichols and
Hull, and had they further known of the emission of
corpuscles revealed to us by the kathode stream and
by radio-active bodies, there can be little doubt that
Young and Fresnel would have had much greater diffi-
culty in dethroning the corpuscular theory and setting
up the wave theory in its place. The existence of
pressure due to waves, though held by Kuler, seems to
have dropped out of sight until Maxwell, in 1872, pre-

dicted its existence as a consequence of his electro-
magnetic theory of light. The first suggestion that
it is a general property of waves is probably due to
Mr. S. T. Preston, who, in 1S76, pointed out the
analogy of the energy-carrying power of a beam of
light with the mechanical carriage by belting, and
calculated the pressure exerted on the surface of the
sun by the issuing radiation. It seems possible that in
all cases of energy transfer, momentum, in the direc-
tion of transfer, is also passed on, and that there is,
therefore, a back pressure on the source. Though there
is as yet no general and direct dynamical theorem ac-
counting for radiation pressure. Prof. Larmor has given
a simple indirect mode of proving the existence of the
pressure which applies to all w.ives in which the average
energy density for a given amplitude is inversely as the
square of the wave-length. He has shown that when a
train of waves is incident normally on a perfectly reflect-
ing surface, the pressure on the surface is equal to
E (i + 2«/L'), where E/2 is the energy density just out-
side the reflector in the incident train, U is the wave-
velocity, and u the velocity of the reflector, supposed
small in comparison with U. In a similar manner it
can be shown that there is a pressure on the source,
increased when the source is moving forward, decreased
when it is receding. It is essential, however, that we
should be able to move the reflecting surface without
disturbing the medium except by reflecting the waves.
Though Larmor's proof is quite convincing, it is inter-
esting to realise the way in which the pressure is
produced in the different types of wave-motion. In the
case of electro-magnetic waves. Maxwell's original
mode of treatment is the simplest. A train of waves is
regarded as a system of electric and magnetic tubes
transverse to the direction of propagation, each kind
pressing out sideways; that is, in the direction of
propagation. They press against the source from
which they issue, agairjst each other as they travel, and
against any surface on which they fall. In sound-
waves there is a node at the reflecting surface. If the
variation of pressure from the undisturbed value were
exactly proportional to the displacement of a parallel
layer near the surface, and if the displacement were
exactly harmonic, then the average pressure would be
equal to the normal undisturbed value. But consider
a layer of air quite close to the surface. If it moves up
a distance, y, towards the surface, the pressure is in-
creased. If it moves an equal distance, y, away from
the surface, the pressure is decreased, but to a slightly
smaller extent. The excess of pressure during the
compression half is greater than its defect during the
extension half, and the net result is an average excess
of pressure on the reflecting surface. Lord Rayleigh,
using Uoyle's Law, has shown that this average excess
should be equal to the average density of the energy
just outside the reflecting surface. In the case of
transverse waves in an elastic solid, it can be shown
that there is a small pressure perpendicular to the planes
of shear, that is, in the direction of propagation, and
that this small pressure is just equal to the energy
density of the waves. The experimental verification
of the pressure of elastic solid waves has not yet been
accomplished, but the pressure due to sound-waves
has been demonstrated by Altberg, working in Lebe-
dew's laboratory at Moscow, the pressure obtained
sometimes rising to as much as 0.24 dynes per sq. cm.
By me.'ms of a telephone manometer it was found that
through a large range the pressure exerted on a surface
was proportional to the intensity of the sound.

" Both theory and experiment justify the conclusion

July, 1905

KNOWLEDGE & SCIENTIFIC NEWS.

153

that when a source is pouring out waves, it is pouring
out with them forward momentum which is manifested
in the b;]ck pressure against the source and in the for-
ward pressure wlicn the waves reach an opposing sur-
face, and which, in the meanwhile, must be regarded
as travelling with the train. It was shown that this
idea of momentum in a wave-train enables us to see the
nature of the action of a beam of light on a surface
where it is reflected, absorbed, or refracted without any-
further appeal to the theory of the wave-motion of
which we suppose the light to consist. In the case of
total reflection there is a normal force upon the surface,
in the case of total absorption there is a force normal
to the surface and a tangential force parallel to the
surface; while in the case of total refraction there is a
normal force which may be regarded as a pull upon the
surface or a pressure from within. In any real re-
fraction there will be reflection as well, but with un-
polarized light, in the case of glass, a calculation shows
that the refraction-pull is always greater than the
reflection-push, even at grazing incidence. An experi-
ment, made by the President in conjunction with Dr.
Barlow, was described to serve as an illustration of
the idea of a beam of light being regarded as a stream
of momentum. A rectangular block of glass was
suspended by a quartz fibre so that the long axis of the
block was horizontal. It was hung in an exhausted
case with glass windows, and a horizontal beam of light
was directed on to one end of the block so that it
entered centrally and emerged centrally from the other
end after two internal reflections. Thus a stream of
momentum was shifted parallel to itself, or in this
particular case a counter-clockwise couple acted on the
beam. By suitable means the clockwise couple on the
block, due to the pressures at the two internal reflec-
tions, was distinctly observed and approximately
measured. The result obtained was of the same order
as that deduced from the measurement of the energy
of the beam by means of a blackened silver disc.

" The extreme minuteness of these light forces ap-
pears to put them beyond consideration in terrestrial
affairs, but in the solar system, where they have freer
play, and vast times to work in, their effects may
mount up into importance. On the larger bodies the
force of the light of the sun is small compared with the
gravitational attraction, but as the ratio of the radiation
pressure to the gravitation pull varies inversely as the
radius if tlie density is constant, the pressure will
balance the pull on a spherical absorbing particle of the
density of the earth if its diameter is about a hundred
thousandth of an inch. The possible effects of radia-
tion-pressure may be illustrated without going to such
fineness as this. In the case of a particle of the density
of the earth, and a thousandth of an inch in diameter,
going round the sun at the earth's distance, there are
two effects due to the sun's radiation. In the first
place, the radiation-push is -^ of the gravitation-pull,
and the result is equivalent to a diminution in the sun's
mass. In the second place, the radiation absorbed by
the particle, and given out again on ail sides, is crushed
up in front as the particle moves forward and is opened
out behind. There is thus a slightly greater pressure
on the advancing hemisphere than on the receding one,
and this appears as a small resisting force in the direc-
tion of motion. Through this the particle tends to
move in a decreasing orbit, spiralling in towards the
sun. As there is good reason to believe that some
comets, at least, are composed of clouds of dust, there
is hope that some of their eccentricities may be ex-
plained by the existence of radiation pressure. If the

particles of a dust cloud circling round the sun are of
different sizes or densities, the radiation accelerations
on them will differ. The larger particles will be less
affected than the smaller, will travel faster round a
given orbit, and will draw more slowly in towards the
sun. Thus a comet of particles of mixed sizes will
gradually be degraded into a diffused trail lengthening
and broadening, the finer dust on the inner and the
coarser on the outer edge. If a planet, while still
radiating much energy on its own account captures and
attaches to itself, as a satellite, a cometary cloud of
dust in which there are several different grades, with
gaps in the scale of size, it may be possible that in
course of time the radiation pressure effects will form
the different grades into different rings surrounding
the planet. -Such may possibly be the origin of the
rings of Saturn."

REVIEWS OF BOOKS.

Geology: Processes and Their Results. By T. C. Chamberlin
and K. D. Salisbury (Murray). Pp. XIX. and 654, plates 24;
21S. net. — This excellently printed and fully illustrated work
will meet with a hearty welcome from English geologists. Its
treatment of the subject is original, and proceeds from the
point of view that the science is a unit, that its one theme is
the history of the earth, and that the discussions of dynamic
geology, physiographic geology, &c., apart from their historical
bearings, lose much of their significance and interest. The
present condition of scientific knowledge is set forth in such a
way that the student will be introduced to the methods and
spirit of the science, and a sympathetic interest excited in its
historical progress.

In a chapter devoted to the work of running water, examples
are freely drawn from North American rivers, in which are
seen every condition of existence, old, middle-aged, and
juvenile. In our countr)', we have few instances which show,
for instance, such as does the Mississippi, the ox-bow lakes,
evidence of the former existence of meanders which have since
been abandoned. Most of our rivers are in a condition of
early old-age, and only by some sudden tilt of either east or
west coast, or an uprising of the central axes of our country,
would rejuvenation of our rivers take place, and the cycle com-
mence over again.

It is pleasing to see the authors utilising the miniature deltas,
which occur anywhere on a muddy coast, or even in a street
in rainy weather, where a drain has been choked up, to illus-
trate the formation of the great deltas of the world. I remem-
ber being greatly struck by the deltas which are formed at the
base of the muddy parts of the Lower Greensand Cliffs, near
Luccombe Chine, in the Isle of Wight. Homely object
lessons can be obtained of immense value from such examples
close at hand.

In the chapter on Structural Features of Igneous Rocks,
the authors discuss the origin of hexagonal columnar struc-
ture. In nature, generally speaking, the hexagon is the
result of the pressure exerted by the walls of circles upon one
another. In the cooling of homogeneous lava, it is postulated
that it contracts about equally in all directions. If the con-
tractile force be regarded as centring about a number of equi-
distant points, then at any one point the least number of cracks
which will relieve the tension in all directions is three, and these
cracks, if radiating symmetrically, would enclose angles of 120°,
the angle of the hexagonal prism. The theory is interesting, but
scarcely explains the breaking-up of the columns into parallel
laminae, nor why the supposititious points about which the con-
tractile force centres should be, almost invariably, immediately
beueath one another. If they were not, the columnar struc-
ture would be lost.

We are so accustomed to talk about the extinct volcanoes
in the moon that we perhaps sometimes overlook the theory
that holds weight in some quarters, that what appear to be
craters may be indentations produced by infalling meteorites
or planetoids. The reproduction of a portion of a photo-

154

KNOWLEDGE & SCIENTIFIC NEWS.

[July, 1905.

graph of the moon's surface in the volume before us certainly
suggests, as a cause of the shallow craters, the falling-in of
bodies, as much as the belching-out of lava or bombs. The
reproduction in another part of the book of fossil rain-mark-
ings bears a remarkable resemblance, on a small scale, to
what have been long regarded as lunar craters, except that the
small central cones are nearly always absent in the former.
This may, however, be due merely to the great fluidity of
water, and because the rain-drops were quickly absorbed in
the sedimentarj- deposit forming, and since the falling body
was more fluid than the receiving body. Let the falling body
be the more solid of the two, then the more fluid will give rise
to a central cone, on the disappearance within of the falling
body, and the permanence or otherwise of the cone will
depend on the degree to which the receiving body has
approached solidity. The subject is fascinating. The moon
may have been the recipient of a bombardment, rather than
the bombarding clement itself.

In the 76 pages devoted to the work of snow and ice we
have this most difficult subject dealt with in an admirable
manner. The illustrations are superb, and show, in many
cases very clearly, the remarkable stratified formation of
exposed sections of glaciers. .Eolian denudation receives
due recognition in the chapter dealing with the atmosphere
as a geological agent, and the migration of dunes are admir-
ably illustrated. There is nothing but praise to be said for
the work, and we hope that it may make its way into every
important library, and into the hands of many who may feei
repelled by the strange. E. A. M.

Electro Chemistry.— Practical Methodsof Electro-Chemistry,
by F.MolKvo Perkin (Longmans, Green and Co.); price6s.net.
— Sir William Ramsay has recently spoken of the enormous
revolution in our chemical industries, only as yet dimly per-
ceived, which awaits the application of electro-chemistry to
their development ; and since what is to-day done in the
laboratory will to-morrow have to be done in the manufactory,
the greatest importance attaches to the establishment of a
sound method in the teachingof electro-chemistry to students.
That end is brought perceptibly nearer by Dr. F. Mollwo
Perkin's sound laboratory guide to these electro-chemical
methods, which in recent years have undergone such rapid
development and have attained such extreme importance.
The volume is above all things practical ; it is what it pro-
fesses to be, a real guide and instructor to the student. The
ground having been cleared by definitions of electrical
magnitudes and units, and by descriptions of measuring in-
struments and electrolytic apparatus, the instruction pro-
ceeds by graduated steps to the actual methods of electro-
chemical analysis. The conditions of the quantitative electro
deposition of the metals; a section on quantitative oxidation
and reduction of the electrodes; the separation of metals from
mixed solutions of their salts ; and finally preparative electro-
chemistry— both of inorganic and of organic compounds — are
the chief divisions of the book and of its instructional chapters.
It is supplemented by a table of five-figure logarithms, with
instructions for their use ; and it bears from title to imprint
the evidence of the carefully considered work of a scientist
who is as well able to impart knowledge as to accumulate and
digest it.

The Rational Almanac (M. B. Cotsworth, Holgate, York;
price 5s. net). This is an odd-shaped book of over 470 pages,
crammed full of writing, diagrams, and illustrations, and it
takes some little time to find out exactly what it is all about.
One naturally turns to the "Summation" at the end, where
one might expect to find some simple and succinct explanation,
but this alone extends over 100 pages, and seems to be a
history of the world from early times. A large part of the
book is devoted to explanations of the probable astronomical
purposes of the Pyramids and many druidical and other erec-
tions, and their practical use in connection with the calendar.
But we need not refer further to them, interesting though they
be. The real object of the book is to suggest a reform in our
calendar, and one in favour of which much can be urged. It
is to divide the year into 13 months of 2H days each. This
would be very convenient, as the days of the week would run
concurrently with the days of the month. It is suggested, to
complete the year, that Christmas Day should be extra, and
not count either as a weekday or day of the month. The
author lays stress on what we should consider another matter, I

that is " the inconvenience which results from drifting Easters,"
&c. These moveable feasts can be, and we think ought to be,
done away with (for business purposes) without otherwise
altering our present well-established calendar.

Studies in General Physiology, by Jacques Loeb. (Chicago.
London: Fisher L'nwin; price £1 iis. 6d. net; 782 pp.) —
These two volumes will be welcomed by all students of Com-
parative Physiolog)', who have hitherto boon obliged to seek
for Professor Loeb's papers in the various American and Ger-
man periodicals in which they have appeared. " Control of
the Phenomena of Life" is the dominant note of his work,
which deals witli the mechanical determination of (a) animal
motion (heliotropism, geotropism, &c.) ; (6) animal organs (re-
generation, heteromorphosis, &c.) ; (r) life itself (fertilisation,
artificial production of normal embryos from unfertilised ova,
&c.) The arrangement of the book is a little tiresome, the
papers being reproduced in order of publication, not grouped
together by subject. On the other hand, the vital interest of
Loeb's work consists in the development of one point out of
another, and we can follow his train of thought from first to
last in these studies. The general reader would do well to
tuni in the first instance to p. 497 of Part II., where he will
find an admirable lo-minutes' lecture on " The Physiological
Problems of To-day " (delivered 1897). In this the importance
of comparative physiology, which " alone enables us to dis-
criminate between the general properties of living matter and
the fuuctions of specific organs, such as the blood, the nerves,
the sense-organs, chlorophyll. Sec." is insisted on. Professor
Loeb pleads for the extension of that field of comp.arative
physiology which he terms physical morphology, or " the con-
nection between the chemical changes and the process of
organisation in living matter," and to this fascinating subject
many of his studies are devoted. Of late he has turned from
the structural phenomena common to plants and animals to
the constitution of living matter itself, as interpreted by
physical chemistry (stereo-chemistry, or the geometrical con-
figuration of the molecule, osmotic pressure, &c.) ; and the re-
mainder of the book is devoted to the brilliant series of experi-
ments upon the dissociation of electrolytes — physiological
action of positive or negative ions, rate of their diffusion
through the living tissues, and so on — by which Proftsi-or Loeb
has, perhaps more than any other physiologist, established the
fundamental importance of ionic dissociation in physiology and
pharmacology.

Animals I Have Known.— In this companion volume to his
" Birds I Have Known," (pp. 304, 40 illustrations ; T,
Fisher L'nwin; price 5s.), Mr. A. H. Beavan states that
it has been his object simply to record his experiences of
animals {i.e., mammals) in various lands, without refer-
ence to scientific theories as to their origin and distri-
bution. Had he adhered strictly to this resolution all
might have been well, and we should not have been informed
that the Australian platypus is the only mammal that lays
eggs, and that the South American vampire abrades the skin
of its victims with its canine teeth. If an author will enter
upon technicalities, he should take means to ascertain that they
arc correctly stated. A large portion of the book is devoted
to the manunals (wild and domesticated) of our own country ;
but Mr. Beavan has had the good fortune lo visit Australia
and South America, and has much to tell us (which is for the
most p.irt well worth reading) concerning the very remarkable
njammalian faunas of those two countries. Of <special interest
are his observations with regard to the tail of the Tasmanian
wolf, which, he says, is essentially part of the creature's body,
and cannot therefore be " wagged." The numerous illustra-
tions are for the most part excellent. If only the author had
asked a scientific naturalist to revise the proof sheets, we
should have had nothing but praise for his little volume.

The Inventor's Guide to Patent Law and the New Practice. — By

James Roberts, M.A., LL.I'., Harrister-atlaw (John Murray),
price 2s. Od. net, too pp. The inventor who is about to take
out a patent, whether already experienced in such matters, or
a novice, will always be glad to consult a small book which
gives clear instructions as to the iiwdiis operamli ol obtaining
the patent, and of the legal procedence, especially now that
several important changes have been m.ade. This book
admirably fulfils the requirement, and, being by a barrister and
author oi a larger work on the same subject, may be looked

July, 1905]

KNOWLEDGE & SCIENTIFIC NEWS.

155

upon as reliable and unbiassed. We are frequently having
foisted upon us guide books of " How to take out a Patent,"
which prove to be nothing more than the advertisement of
some enterprising firm of patent agents, and such works,
though frequently quite correct, one is bound to regard with
a certain amount of suspicion.

Electro-magnetic Theory of Light, by C. E. Curry, Ph.D.
Parti.; pp. \i. + 400. (London: Macmillan ; 12s. net.) —
This is one of those books of which we would speak nothing
but good if we could. It has evidently been laboriously com-
piled, and the whole ground has been covered of that portion
of the theory which was developed by Maxwell himself. More
modern developments which must includesuch matters as dis-
persion, which was left unexplained by Maxwell in his Treatise
[but which were niuhi'stood by him as is shown by an examina-
tion question set by him — as pointed out by Lord Rayleigh] ,
have been relegated to a second part. Each section is fol-
lowed by a large number of examples, very many of which have
been excellently chosen. Since these are often worked out in
detail they form an excellent means for a student to familiarise
himself with the subject. When we have said this, however,
any praise of a fairly enthusiastic kind is at an end. The
style in which the book is written is not good ; indeed it is re-
pellent. We have pored over many paragraphs without being
able to obtain their meaning. Special points which seem to
be peculiar to the author displease us most of all. We do not
like his use of the phrases primary and secondary waves in a
sense distinct from that in which they are already used — viz.,
in connection with Hugyen's theorem.. Still less do we approve
of the whole page devoted to a fanciful analogy to primary and
secondary currents by which an attempt is made to justify the
new use to which he puts these phrases. Simple methods of
proof of theories which are familiar to us are replaced by
elaborate and confusedly stated methods without any gain in
accuracy. On the whole we have said enough to indicate our
opinion ; and conclude by stating that the publishers have
done their part in a most excellent manner.

The Norwegian North Polar Expedition, 1893-6. Edited by
Fndtjof Nansen. Vol. VI. (Longmans, Green and Co.;
price 56s. net.) This great volume deals with the meteoro-
logical results of the expedition, and is the work of Professor
H. Mohn, who planned the meteorological work to be con-
ducted, and superintended the equipment sent with the Frain.
Such a great work, conducted with skill and care, forms an
important addition to scientific literature. The observations,
continued through three years of travel in regions hitherto
unknown, were mostly conducted by Captain S. Scott Hansen,
who had received special instruction in this subject from Pro-
fessor Mohn. The book is[maiuly divided into three portions;
the first describing the instruments and observations; the
second, the actual diary tables of observations ; and the third
the results worked out. The observations were made every
four hours, and show the direction and velocity of the wind,
the barometric pressure, the temperature, the vapour-tension,
relative humidity, and clouds. As regards the direction of the
wind, which, by the way, has an important bearing on the
probabilities regarding the fate of the Andree expedition, a
cursory glance would lead one to suppose that the various
winds were fairly equally prevalent, some predominating at
certain seasons. The value of this collection of observations
is the more evident seeing that they extend over three years,
for otherwise one might be led into supposing that certain
winds predominated during certain months; but the records
of other years seem, in most cases, to prohibit any such con-
clusion. In July, the month during which Andree started in
his balloon, the prevailing winds were — 1894, W.N.W. and W. ;
i8y5, W. and W.S.W. ; 1896, S.W. and S.S.W. As regards
the velocity of the wind, the monthly means vary from about
three to five metres per second. The velocity, as may be
expected, was on the average greater during cloudy weather
than with a clear sky. The maximum velocity recorded was
only 18 metres per second, and the occasions were very rare
when this figure was approached, so that anything approach-
ing a real storm was rare. The barometric pressures call for
no comment, varying as a rule between 740 and 780 mm.,
but when we come to temperatures we find some unusual
figures. The coldest month was apparently March, with a
mean of —37^^ C. the mminnim recorded being —52°. In July
and August we occasionally find a mean daily temperature

just above freezing point. At the end of the book are a
number of charts and diagrams.

Ambidexterity, or Two- Handedness and Two-I5rainedness. By

John Jackson (Kegan Paul). This is a large book to devote to
so little-studied a subject, and we hope it may be the means of
bringing forward the importance of that most useful accom-
plishment of being able to use both hands, or perhaps we
should say either hand, for all ordinary purposes. To be able
to write two letters simultaneously, or to draw two different
pictures at the same time, is certainly an extraordinary feat of
dexterity, but is now described as being easily learnt. One
hand at a time is, however, sufficient for most people to em-
ploy, and it is certainly desirable to acquire the knack of
using the left hand for writing and other purposes.

A Catalogue of Zodiacs and Planispheres, by the Rev. A. P.

Grimaldi, M.A. (Gall and Inglis), is a most useful compilation
describing the various records from the earliest times of
zodiacs in all countries. The number of entries is 1,444.
Some of them are a little vague, as, for instance, No. 148,
which reads: " A Chinese zodiac is mentioned by Pettigrew,"
and but few of them have the date or supposed age of the record.
Nevertheless, the list should prove of great value to all inte-
rested in this subject.

Petrol Motors Simply Explained. By T. H. Hawley (Percival
Marshall; price, is. net). This is one of those useful little
manuals intended to instil into the mind of the Man in the
Street some knowledge of the working of the machine that
carries him about. In the preface the author explains that
"the object aimed at is rather a simple explanation of the
principles governing the action of the petrol motor, and the
manner in which the power so generated is utilized to propel
the vehicle, together with a few hints on control mechanism
and driving."

Notes and Questions in Physics. John S. Shearer, Ph.D.
(Pp. vii. + 281. New York: The Macmillan Company;
London: Macmillan and Co. ; price 7s.6d.net). — The object
of this volume is to provide a collection of examples in physics
with a sufficient number worked out to suggest methods in
typical cases. The fact that students continually complain of
their inability to solve .simple problems in physics is a clear
indication that the fundamental principles are not fully
grasped ; and it is essential therefore to supplement lecture
and laboratory work by a reasonable amount of problem
work. It is in this way only that a student learns whether he
has really understood a principle. The greater number of
the problems selected here can be worked by simple algebra
or arithmetic ; though in a few cases the calculus is necessary.
It is obviously intended that the book should be used with the
assistance of a teacher, since answers are not given ; the
private student is hereby put at a disadvantage, for he has no
test as to the accuracy of his work. There is surely very
little objection to including the answers in any book of colle-
giate standing, whatever method may be found best for a
school book. If a student who has come to years of discretion
thinks right to merely " crib " the answer he reaps his reward.
Such a man will prove of little use in this world, at any rate.
The problemsare judiciously chosen, so that both the academic
and the technical student is catered for. We notice a few
mistakes. There are unfortunately some in the tables at the
end. When are text-book writers going to realize that the
fundamental standards of mass and length are no longer the
old ones " kept in the Archives at Paris." Is the work of the
International Bureau a small thing that it should be so
ignored ?

Elementary Microscopy. By F. Shillington Scales, F.R.M.S.
(Bailliere, Tindall, and Cox; price 3s.) A handbook for begin-
ners, which is thoroughly practical, concise, and explanatory.
With so many modern improvements of detail, most of the
larger handbooks on the microscope are becoming out of
date, and they are, moreover, as a rule, slightly beyond the
requirements of the mere beginner, who wants toknow in as
few words as possible what sort of instrument to purchase
and how to use it. " Nature, as revealed by the microscope, is
quite outside the scope of this little book," which is very
properly confined to descriptions of the instrument and its
accessories, with hints on its manipulation, and methods of
mounting objects for inspection. There are 78 good, clear

1=^6

KNOWLEDGE & SCIENTIFIC NEWS.

[July. 1905.

illustrations, and a useful list of the principal books on the
subject is added.

Natural Hlstor>' in Zoological Gardens. — By F. E. Beddard,
F.R.S., <\;c. (London: .Archibald Constable and Company,
Limited; price, 6s. net). From his position as head of the
coroner's (otherwise " prosector's ") department at the estab-
lishment in the Regent's Parli, the author of this well-illustrated
little volume of something over three hundred pages has
enjoyed unrivalled opportunities of acquiring information with
regard to the manners ajid customs of animals in menageries ;
and when we first opened the covers we were in hopes of
finding that such information had been made public, and that
we should find out the average lengths of the lives of different
species in captivity, and from what causes they generally
perish. To our intense disappointment, we soon found that
the work, although it undoubtedly gives a few data on these
points, is of a totally different class, l)eing, in fact, a kind of
sketchy natural histor\- of terrestrial and al-rial vertebrates, as
exemplified mainly by species to be met with in zoological
gardens. From this point of view (and we have really no
right to criticise it for what it is not) the book may be pro-
nounced as fairly satisfacton,-, and as conveying a large amount
of information, although, from the nature of the case, com-
paratively little is novel. Mr. Beddard treats his subject from
the systematic point of view, and consequently takes the
various " orders " and species in serial sequence, devot-
ing the largest amount of space to mamm;ils, and omitting
fishes altogether, as being not generally represented to any
important extent in menageries — unless, indeed, as food for
seals. For the .same reason whales are omitted from the
pur\'iew; and it is on account of such omissions that we think
the work would have been much better if the animals had not
been described systematically. As a minor matter, we confess
to being utterly puzzled by the titles selected for some of the
chapters. For instance, we find the fourth headed the
'• Deerlet," and yet it contains notices of such animals as
elephants, lions, tigers, &c. ; while under the title of the '• Polar
Bear " we find included such animals as seals and rodents.
Surely no chapter-headings at all would have been far prefer-
able. Again, we must venture to take exception to some of
the absurd " English " names manufactured for some of the
animals described, such as (p. 285) the " adorned ceratophrys,"
which is a survival of the old bad principle of attempting a
half-translation of the scientific names once adopted generally
in the gardens. As regards illustrations, the book is for the
most part all that can be desired ; and, although it cannot be
described as of enthralling interest, while, in our opinion, it
would be all the better for the omission of many passages
which we suppose are meant to be humorous, it undoubtedly
contains a very large amount of zoological information.

A Student's Text-Book of Zoology, by Adam Sedgwick, F.R.S.,
&c. Vol.11. (London: Swan Sonnenschein and Co., Ltd.).
— That any one individual should attempt at the present day
to write single-ba:idcd a detailed scientific text-book dealing
with the whole realm of zoology, and, what is much more,
should be capable of doing so in a more or less masterly
manner throughout, is little short of marvellous. Never-
theles.s, this is the gigantic task to which Mr. Sedgwick has
committed himself, and the present volume and its predecessor
afford convincing proof that he has over-estimated neither
his scientific abilities nor his powers of long-continued and
close work. Faults and imperfections must of necessity make
their appearance in such a work, but the wonder in the present
case is not that they are so many, but rather that they are,
comparatively speaking, so few. Whether it is really advis-
able for a single writer to undertake a t.isk of this colossal
magnitude, and whether it is not preferable to follow the pre-
vailing fashion of a " symposium " in the making of works of
this nature, may be an open question. It is certain, however,
that undivided authorship permits of the subject being treated
in a much more uniform style than would otherwise be possible,
and it ensures that all parts of it are viewed, so to speak,
through the same glasse.s. In the present instance it may be
confidently asserted that few, if any, biologists in this country
at any rate would be capable of c.irrying out the task in the
manner in which .Mr. Sedgwick has so far acquitted himself.
That an author can write throughout a work of this descrip-
tion from first-hand knowledge is, of course, a manifest im-
possibility ; and in the present volume Mr. Sedgwick candidly

acknowledges his indebtedness to several contemporary
specialists. For his account of the bony fishes he has. for
example, drawn almost exclusively from the recent work of
Mr. Boulenger ; and critical zoological readers who carefully
scrutinize the definitions of the various groups will scarcely
fail to detect that they have been drawn up by one who is not
an expert on the subject, and that in certain instances they
are not absolutely diagnostic.

While the first volume deals with molluscs and the lower
invertebrates, the one before us is devoted to the chordata,
as restricted by the author; that is to say, the lancelet (mis-
called .•1hi/>/ii().Vi/s) and the vertebrates, in the third volume
are to come the ascidians, acorn worms, echinoderms, and
arthropods; while in the fourth and final volume will be dis-
cussed the general principles of zoology.

Perhaps the most striking feature of this portion of Mr.
Sedgwick's work is the vast amount of information he has
managed to convey within the limits of one fair-sized octavo
volume ; it has, of course, been practicable to effect this only
by condensing statements in the greatest possible degree ; and
this very concentration is of itself a sufficient proof of the
enormous amount of labour that has been expended on the
task. On the whole, the author is well up to date in his facts,
this being especially noticeable in his treatment of the Probos-
cidea and their apparent relationship to the Sirenia. On the
other hand (p. 539), in referring to the marsupial ^[yrm(cobms
as being allied to the Jurassic mammal?, he appears to have
overlooked the recent work of Mr. Bensley. In regard to the
scheme of classification, we arc compelled to dilTor from the
author in many points, notably in regard to the separation of
the bony fishes from their enamel- scaled forerunners, and in
the refusal to accord to the egg-laying mammals a taxonomic
rank higher than that assigned to the various " orders " of the
placental group, which, by the way, are more numerous than
is admitted by many authorities. Neither do we like to see
the mammal-like anomodont reptiles placed between plesio-
saurs and chelonians, instead of at one end of the class. To
an already fairly long list of corrigenda, the following items
may be added : The edentates of S. America do not date
from the Lower Eocene or Cretaceous (p. 543). Lipoterna is
given throughout in place of Litoptorna. Ai;Iossicl(c (p. 309)
is not the family name for the Surinam toad and its relatives.
The present reviewer is wrongly credited with having written
a book entitled " Deer and their Horns" (p. 5.SS). The state-
ment (p. 599) that whalebone sold for /J150 per ton in the
early part of the 15th century surely refers to the i8th century.
" Style " cannot be expected in a work of this nature, but it is
certainly unnecessary to make six consecutive sentences begin
with the word " they," as on page 551. Although some of the
illustrations are excellent, the less that is said about a large
proportion the better.

Despite imperfections, many of which, from the nature of
the case, could scarcely have been avoided, the volume is worthy
of every commendation, if only as an example of hard and
conscientious labour.

Our Stellar Universe : A Road-Book to the Stars, byT. E. Heath,
the author of an article appearing in this issue of " Know-
LiciK.ic." has been received, and will be reviewed in our next
number.

Smithsonian Miscellaneous Collections, vol. ii. part 3, has a
varied assortment of interesting papers, Including " Inquiry
into the population of China," by W. W. Kockhill ; Seeds of
Aneimites," by David White ; "The Sculpin and its habits,"
Theodore Gill; "The Construction of a Vowel Organ," Ii. W,
Scripture ; " Habits of a Social Spider," " Fossil Plants," and
others.

Graphs for Beginners, by Walter Jamieson (Hlackieand Son),
IS. Od., and Uasv Graphs, by II. S. Hull, M.A. (Macniillan), is.,
are two little works dealing with the same subject. The first-
named treats of graphs from a general point of view, as a
means of creating interest, cultivating habits of observ.ition,
and stimulating the reasoning powers, rather than as a branch
of pure mathematics. The second book is very similar in its
general scope, and is also intended for beginners.

Griffin's Catalogue of. Sclenlllic Apparatus, in three parts, i in-
cluding Mechanics, Hydrostatics and Pneumatics; 2, Sound,
Light and He.it; and 3, IMectrlclty and Magnetism, is a very
complete, descriptive list of apparatus useful and necessary
to the physicist.

July, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

157

ASTR.ONOMICAL.

By Charles P. Butler, A.R.C.Sc. (Lond.), F.R.P.S.

Further Notes on Jupiter's Sixth and
Seventh Satellites.

Professor Peukinic, the discoverer of these two new satellites,
has recently published a short raiime of their features as at
present determined. He makes the interesting suggestion
that the large inclinations of the orbits of both satellites to the
plane of the planet's equator may be an indication that these
bodies have not always belonged to Jupiter, but that they may
be captures.

Sixt/i Satellite. — Owing to its brightness this has been
readily photographed in ten minutes with the Crossley re-
flector, and plates have been obtained on thirty-six nights, the
last date of observation being March 22, as the planet is now
too near the sun for the satellite to be examined.

A preliminary examination of the orbital elements shows
the inclination to the ecliptic and the planet's equator to be
about 30°. The period is probably about 250 days, with a
mean distance from the primary of about 7,000,000 miles ; but
it is not yet possible to say with certainty what is the direction
of the orbital motion. The actual diameter cannot be mea-
sured, but the determinations of brightness indicate a diameter
of 100 miles or less.

Seventh Satellite. — A minute examination of negatives of the
sixth satellite, taken with the Crossley reflector in 1905,
January 2, 3, 4, showed the presence of a much fainter object,
which apparently belongs to Jupiter. It was at that time to
the N.W. of Jupiter, and had a motion towards the planet.

The many difficultios which presented themselves in deter-
mining the true character of the sixth were still greater in the
case of this newer one. Being so much fainter, the observa-
tions were more difficult to secure, owing to the long exposures
required, and its motion was likewise harder to interpret. It
was considered, however, that the determinations of Feb-
ruary 21 and 22 made it clear that it belonged to Jupiter.
The seventh satellite is not shown on the negatives taken
during December, 1904, as it was just outside the field then
under observation. Definite measures have been secured on
the results of 20 nights, the last of which was March 9.

A preliminar}' investigation shows the orbit to be quite
eccentric, the mean distance from Jupiter being about
6,000,000 miles, with a period of about 200 days.

The orbit is inclined to the plane of Jupiter's equator at an
angle of about 30', but the direction of motion is at present
uncertain. Its photographic magnitude is estimated to be
not greater than the 16th. From this fact and a comparison
with the other satellites and the asteroids it is probable that
the seventh satellite has a diameter of about 35 miles.

A ProbsLble New Star, R.S. Ophiuchi-

In a special communication from the Harvard College Ob-
servatory Professor E. C. Pickering draws attention to further
observations of this so-called variable star, which shows cer-
tain peculiarities similar to those seen in novze.

New stars can be distinguished from variables, in many
cases, only by their spectra. The usual life of a new star is
marked by its sudden appearance where no star is previously
known to have existed, and a gradual fading away during which
it changes into a gaseous nebula. T Coronje, Nova Persei, P
Cygni, and i) Carinas are instances of varied development.

It is found that on July 15, 1898, the spectrum of the star
R.S. Ophiuchi was of the third type, in which the Hydrogen
lines H^, H7, H5, Ht, Hi were bright, and also two lines which
appear to coincide with the bright bands in the spectrum of

7 Velorum at \ 4656 and X 4691. This spectrum, therefore,
closely resembles that of Nova Sagittarii, and also of Nova
(ieminorum. A photograph taken on July 14, 1898, confirms
the presence of the bright lines, while another taken on
August 28, 1894, showed that at that time the spectrum was of
Class K, with no evidence of bright lines.

From an examination of the photometric light curve of the
star it was noticed that there was a remarkable increase during
the year i8g8. Before 1891 the magnitude, as determined
photographically, was io'9 ; it then increased gradually about
half a magnitude to 10-4 in 1893, and retained this until 1897.
In 1898 it was at first faint (io'8) until May 31. A month
later, on June 30, it was 77, more than three magnitudes
brighter, and after that it decreased regularly about a magni-
tude a month until October 8, when it again reached the value
i0'8. The following year, 1899,11 remained faint at io"6, but
in April, 1900, it again brightened to 9^3, diminishing to lo'o in
September of that year. Since then the variations have been
only slight.

An examination of several good chart plates shows only one
star in this position, and both the spectrum and light curves
thus indicate that this object should be regarded as a nova
rather than a variable star. In this case its proper designa-
tion would be Nova Ophiuchi No. 3, the new stars of 1O04 and
1848 having also appeared in the same constellation.

Observations of Heliunn Absorption in
the Sola.r Spectrum.

The number of occasions on which reliable observations
have been made of the absorption spectrum of helium in the
solar spectrum are so few that considerable importance must
be attached to all authenticated instances. Probably the first
recorded determination was that by Young on 22nd September,
1870. A few months ago a paper was read before the Royal
Astronomical Society by Professor A. Fowler, in which he
recorded having distinctly seen the dark D^line of Helium in
the neighbourhood of the great sunspot of February, 1905.

Quite recently Dr. H. Kreussler, of Berlin, has published an
account of twogood observations of thephenomenon, obtained
on the lathand 13th June, 1904. The instrument used was a
fi-inch reflecting telescope, with a spectroscope magnifying 8
diameters, the slit being in the region of the penumbra of a
large spot. It was noticed that the faculze surroundirgthe mn-
spots were very bright on both days.

He suggests that the present appearance of this peculiarity,
considered with the above - mentioned observation of Pro-
fessor Young, appears to indicate that the phenomenon may
be characteristic of the period of maximum sunspot
activity.

Comet 1905 (a).

The following elliptic elements for the orbit of the Comet
1905 (a) have been determined by Herr A. Wedemeyer from
a computation of the observations obtained on March 26 at
Nice, and on April 8, 28, at Vienna : —

Elements.

1905 April 4'oggi I
35S' 13' 20" 3)

Jerlin

Mean Time

157 23 27-8 1905
40 14 38-4 )

9-988506

0047307

1-630354
279 years.

EpHEMERIS for 12 H. BERLIN MeAN TlME.

Date.

Right Ascension.

Declination.

h. m.

0 ,

July I

13 20

+ 39 441

,.3

39 2-1

..5

38 20-0

,,7

37 377

..9

36 553

,, II

13 46

+ 36 12-9

KNOWLEDGE & SCIENTIFIC NEWS.

[Jl'LY, 1905.

The New Tenth Satellite of Saturn.

Very little has been published since the discovcn- of the
tenth satellite, but the details are now definitely stated in a
communication from the Hanard College C)bservatory.
The satellite was discovered by Professor \V. H. Pickering
at the Harvard College Observatory during the examination
of a series of several photographic plates taken with the
24-inch Bruce telescope, selected from the set used in deter-
mining the orbit of Phcebe, the ninth satellite. The new
satellite was detected on thirteen of these plates, and the
previous announcement of the orbital motion being direct with
a period of twenty-one days is confirmed ; it is now stated to
be nearer Saturn than Hyperion.

Photography of the Canals on Mars,

In a telegraphic communication to Professor E. C. Pickering,
Mr. Lowell announces that numerous photographs of several
of the dark canals on the planet Mars have recentl)' been
obtained at the Lowell Observatory by Mr. Lampland.
Amongst others the following are specially mentioned as
appearing quite distinctly, some being recognised ou as many
as twenty negatives: — Casius, N'e.xillium, Thotb, Cerberus,
Helicon, Styx, Chaos, Liedeus.

CHEMICAL.

By C. A. Mitchell, B.A. (Oxon.), F.LC.

The Action of Light Upon Glass,

Sir William Ckookes has communicated to the Royal Society
(Procicdings, April, 1903) the results of experiments upon speci-
mens of coloured glass sent to him by correspondents in
Bolivia and Chili. The pieces of glass, which had originally
been white, ranged in colour from pale amethyst to deep violet
black, and the colour was not superficial but permeated the
whole substance. It could be destroyed by heating the ghss
until it became soft, and restored again by exposure to the
rays of radium. Manganese was found to be present in each
case, and as the glass had been exposed to direct sunlight at
an altitude of 4000 metres above the sea, Sir William con-
cluded that it was possible that at that height there might be
specially active rays in the sunlight which would convert the
manganese present into the violet coloured manganic silicate.
In his opinion the colour produced in glass by radium was the
same as that caused by long exposure to the sun's ra}s. In
the discussion Professor Judd called attention to the fact that
the glass in some of the old greenhouses in Kew had changed
from its original green colour (due to iron oxide), and after
becoming colourless had gradually turned violet, and he
attributed this to the manganese in the glass. It is interesting
to note that Faraday, in 1825, recorded the occurrence of
similar colorations in the windows of certain houses, now pulled
down, in Blackfriars Koad, after nine months' exposure to sun-
light. Mr. W. H. Low, in a letter to the Chemical Scus, re-
ports that he has observed numerous instances of the same
kind in old window glass in many of the hoiises in Boston,
U.S.A., the colours ranging from pink to violet and almost blue.
The houses face east and are in low situations, so that the
altitude cannot be one of the factors in this case. He asserts
that a regular gradation in colour can be produced by covering
successive portions of window glass with black paper and
allowing each uncovered portion to be exposed to sunlight for
a month longer than the preceding portion. Herr F. I^ischcr
has also made experiments as to the influence of the light from
an incandescent mercury lamp of special construction, the
rays from which he concludes to be those of ultra-violet light.
Of the eight kinds of glass tried, four, including a (ierinan
lead glass and an English lead glass, were outwardly un-
changed, while four were coloured a decided violet within 12
hours, the coloration becoming visible after :5 minutes. All
of these contained manganese, whereas the uncoloured four
were nearly free from compounds of that metal. Heat de-
stroyed the colour, but if could be restored by a fresh exposure
to the light. When the glass was covered with thin sheets of
mica no coloration was produced, and it was therefore con-
cluded that the effect was due to radiations of short wave
length. Herr Fischer also suggests that the violet colours

produced in glass by Rontgen tubes may be due to ultra-violet
light acting on the manganese in the glass, and that the similar
effect caused by radium may also be connected with radiations
of short wave length.

The Prevention of Poisoning by Mercury
Vapour.

The workmen in the quicksilver mines and, to a less extent,
those engaged in the manufacture of barometers and other
instruments in which mercury is used, are liable to suffer from
a peculiar form of poisoning produced by continually breathing
mercury vapour. The disease, which is known as " the
trembles," or " mercurial tremor," affects the nervous system,
so that the sufferer is attacked by fits of trembling whenever
any attempt is made to use the muscles, and it eventually
ends in death. In the mines in Sp.iin, Austria, and America
it is usual to remove workmen to other parts of the works
comparatively free from the vapour, so soon as they show the
characteristic signs of poisoning ; but the Spaniards in South
America did not pay even this amount of attention to their
miners. A mining community was founded towards the close
of the i6th century at Hunncavelica, in Peru, to work the
celebrated mine of St. Barbara, in which is a subterranean
village with a church cut out of the cinnabar. This mine was
a great source of profit to the Spanish, and it is estimated
that during their rule thousands of the Indians driven to work
there died of mercury poisoning. No serious attempt appears
to have been made to grapple with this evil except that in
certain mines better systems of venlilation have been adopted,
and it has been left to an Italian chemist to devise a simple
means of prevention. Dr. Tarugi has found that aluminium
in a finely-divided state immediately absorbs mercury even
when only traces of the metal are present in a large volume
of air. The amalgam produced is very stable, and can be
heated (o 200° C, or twice the temperature of boiling water,
without losing the slightest trace of mercury. This absorptive
power of aluminium is so great that the reaction can be used
as an extremely sensitive test for mercury. In order to utilise
this property cf aluminium in the prevention of mercury
poisoning. Dr. Tarugi has devised a respirator containing
several layers of very fine aluminium gaiue, which will allow
the air to pass whilst retaining every trace of mercury vapour.
This respirator has been patented in Italy, Austria, and
Spain, and will probabh' before long be adopted in all quick-
silver mines.

Tlie Consun\ption of Odoriferous
Constituents by Pla-nts.

The results of interesting cxperimtnis jii basil plants have
been published by MM. Charahot and Htoert. One set of
plants were kept in the dark for six weeks and another under
normal conditions for the same period. The amounts of
essential oils (to which the perfume is due) were determined
before and after the experiments, and it was found that they
had increased twenty-fold in the plants kept under ordinary
conditions, while there was a notable decrease in the case of
the plants kept in the dark. Hence it appears that the
odoriferous constituents of basil are not fimply products of
excretion, but that under certain conditions they can be
utilised to supply some of the energy not given by the light or
to form tissue.

GEOLOGICAL.

By Liav.\j;d A. M.\i<tin, F.G.S.

Coal.

The Report of the Royal Commission on Coal Supplies has
served to emphasize one fact very clearly, namely, that in
spite of all fears which have possessed the British people for
forty years as to the p<issible exhaustion of our coalfields,
such fears have very little reason for their existence, and at
least for half a niillenniuin, even with the present rate of con-
sumption, there will be no shortage of supply. We are, in
fact, only just at the beginning of the "coal-using age." In
1820 Britain raised but 20 millions of tons of coal. Now she
raises 230 million tons a year. If she continue to use coal to

July, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

159

the same extent as now, she has five centuries before her, and
during this period it may safely be said that no one will feel
the t^radual exhaustion which will be taking place. But the
Commissioners point out in their report what other thought-
ful men have pointed out before, that other considerations
will come into play which will probably have the effect of
reducing the rate of increase of output, until finally the
immense existing output will actually decline. Not im-
probably by the time that our coal supplies are approaching
exhaustion, the greater portion of the demand will have
ceased, and other means of lighting and heating will exist
other than that to be obtained from coal.

Foreign Coal.

When we look at deposits of coal which are found abroad
we may be fairly astounded at the wealth which some conti-
nental countries possess, and it is as well that there should be
a clear understanding that the foreign supplies of coal bear
much the same proportion to our British supplies as an
elephant does to a mouse. No human agency can ever ex-
haust the world's supplies. But frequently they are so situated
as to be practically valueless. They are in a similar category
to what the Commissioners called the " unproved " coalfields
of Britain, and the seams at depths greater than 4000 feet,
below which no mine is known to exist. China has rich
possessions of coal. Many of the seams are near centres of
population, and are easily worked. In the mountainous areas
of western China coal-measures are found in great profnsion,
and seams from 30 feet thick and upward have been traced in
a horizontal plane for 200 miles towards the Mongolian fron-
tier. But at present they are practically valueless, and, like
our own deep-lying seams, require engineering skill such as is
not now to be found for their development.

The Age of Diplodocus.

At the official presentation to the Natural History Museum
of the replica of Diplodocus Canuxii-, the curator of the Car-
negie Museum was reported to have alluded to the age of the
monster Dinosaur as four thousand centuries. English geo-
logists do not as a rule care to speak of the age of any par-
ticular formation or fossil in terms of years. Years are such
insignificant items where geological ages are concerned, and
every estimate so made is certain to be open to very great
error. But it is impossible to conceive by what means of cal-
culation a creature of Jurassic age can be said to be but 400,000
years old. Geologists have for years fretted under the reign
of those physicists who say that no form of life was possible
on this earth before 100 millions of years ago. And in view of
possible discoveries in connection with radio-active bodies in
the future, it becomes increasingly difficult to place a period
either to the time at which the sun began to give out heat, or
when it will cease to do so. Geologists will, I am convinced,
find themselves compelled to tear themselves away from all
restrictions of time placed upon them by those who are first
physicists and after geologists. The more the facts of geology
are borne in upon one, the more, as it seems to me, is it
impossible to see the possibility of all the great geological
phenomena having taken place in less than 250 millions of
years. By a process of calculation on this basis, the age of the
Diplodocus, namely, the Jurassic age, came to a close 415 mil-
lions of years ago. This is, however, only an estimate ; but it
is likely to be .nearer the truth than the utterly insufficient
number of years previously given.

ORNITHOLOGICAL.

By W. P. Pycraft, A.L.S., F.Z.S., M.B.O.U., &c.
The Habits of the Kagu.

The Kagu (Rhinociicctus juhatus) is one of those rare and
aberrant types which seems likely to disappear from off the
face of the earth, leaving but little save its skin and a few
particulars of its anatomy for the ornithologist of the future
to remember it by. Though a native of New Caledonia,
according to some, its nearest ally is the equally rare and un-
known Mesites or Madagascar Kagu, while others regard it as
more nearly related to the Sun-bird [Eurypga helias) of South
America, This, too, is an aberrant type.

All that appears to be known of its eggs and nesting
habits we owe to observations made on a pair of these birds
in captivity and recorded in the current number of the Emu.
A pair, kept in an aviary at Sydney, built a nest of a few
coarse sticks and leaves, in which was laid a single egg. This
was then surrounded by more sticks and brooded continually
by the cock bird, relieved occasionally, it is believed, and
during the night, by the female. Incubation lasts five weeks.
If the egg be removed, another is laid, and this will be
replaced, if taken away, two or three times. The egg is here
described as bearing a striking resemblance to that of a gull,
from which it differed only in the fine texture of the shell.

This is curious, inasmuch as an egg dropped by one of these
birds in the Zoological Gardens in London, and now in the
British Museum, bears as close a resemblance to that of the
Southern Courlan (A ramus scolopaceus), being perfectly elliptical
in shape, cream-coloured, spotted and blotched with dark
brown and purplish grey. It differs from the Courlan's egg,
however, in being without gloss, and slightly rough in texture.

The Hunting Tactics of the Sea Eagle.

A writer in the Field (June 17) gives a short but interesting
account of his observations on the habits of the white-tailed
Sea Eagle (Haliictus albicilla) in Greenland. In summer its
principal food is salmon, varied by sea-birds common along
the inlets. In autumn, when the salmon have ascended to the
lakes, the birds resort to the sea. They appear to have a
special fondness for eider duck, which are taken by strategy.
" Stationed near the water in a commanding position, with a
background of cliff, the colour of which assimilates with that
of the eagle's plumage, he sits motionless, until a flock of duck
settles near him. After a time one or two dive in search of
food, but not until all have gone under together does the eagle
make a sign. He then glides swiftly to the spot, and circles
over it close to the water ; with his sharp eye he can detect
the birds before they reach the surface. At first he is not
usually successful, for as soon as they become aware of the
presence of the enemy, they dive again instantly; but in time
they are obliged to come up for air, and then one of them
becomes an easy victim." A full-grown eider drake is easily
lifted up and borne away in the talons of this powerful pirate.
Most of the sea-fowl, it is interesting to note, readily dis-
tinguish between the Sea-Eagle and the falcon when on the
wing and vary their tactics, and escape capture accordingly.
Thus, when pursued by the falcon they dive, but in fleeing
from the eagle they depend on their ability to turn rapidly on
the wing, which the eagle is unable to do.

Golden Orioles in Stratford.

Mr. Reginald Hudson, in Nature A'o/c'sfor June, records the fact
that a pair of Golden Orioles were seen in a garden on
April 27, at Shottery. Whether they have so far been allowed
to remain unmolested, we cannot say ; if they have, in all
probability they will nest here. As many readers are
doubtless aware, the Golden Oriole has more than once
reared its young in these islands, and were they not so
mercilessly shot down on every occasion, these gorgeous birds
would doubtless more frequently visit us.

Iceland Gull in the Moy Estuary.

Mr. R. Warren, in a somewhat sarcastic note in the Irisli
Naturalist for June, records the fact that an immature Iceland
Gull, Laruslcucoptcrus, was shot by himself in the Moy Estuary
on April 26. He gives the following measurements: —
Length, 2\\ Ins.; capus, 16 ins.; tarsus, 2 ins.

Tufted Duck Breeding in Co. Mayo.

."Xccording to the Field (June 17) : Three or four pairs of
Tufted Ducks, Fuligula cristata, appear to be breeding this
year on Lough Conn, where a nest of eleven eggs was seen by
Mr. S. Scroope. The nest was identified by a piece of down
sent by the Editor of the Field to Mr. Whittaker, of Rain-
worth. Thus the extended breeding range of this bird in Ire-
land, to which Mr. Ussher has drawn attention (Birds of
Ireland), is confirmed. In the volume just referred to, it is
stated that the portions of Ireland where this bird is not
known to breed include, amongst others, " the province of
Counaught west of the Shannon, and Lough Arrow, in Sligo."
Lough Conn lies a little less than 30 miles from Lough Arrow.

i6o

KNOWLEDGE ^: SCIENTIFIC NEWS.

[Jul

1905.

PHYSICAL.

By Alfrel) W. Porter, B.Sc.

Ether Drift.

The question as to whether or not the earth carries the
ctlur near it in its journey through space is one of very great
theoretical importance, and the last word upon it has not yet
been said. The fact that stellar aberration has the same value
whether determined by means of an ordinary telescope or by
one filled with water can most simply be explained by sup-
posing that in the xiuter the ether is carried forward with a
portion only of the earth's velocity, while in the air round the
telescope it is sensibly at rest in space.

On the other hand, the results of Michelson's and Morley's
experiments with their interferometer can be accounted for
most simply by supposing that both the earth and the ether
near it are moving with the same speed; that is to say, that
the earth drags the surrounding ether with it in much the
same way as that by which a layer of air is carried by a pro-
jectile.

Experiments by Sir O. Lodge on whirling massive discs
prove that they at any rate exert no perceptible drag ; and.
consequently, if the earth does so, it must be due to its great
magnitude. It was pointed out by FitzGerald (and inde-
pendently by Loreotz) that if we suppose that the length of a
body when set moving is shortened in the direction of that
motion then Michelson and Morley's experiments do not
imply the absence of relative motion ; in fact, if the shortening
takes place to an appropriate extent, they do not show that
the ether is moved at all. Other experiments have also been
made which seem to require that this supposed shortening is
real.

Morley has recently {Philosophical Magazine, May, 1905)
varied his previous investigation with the object of testing
whether the compensation which cancels the effect due to
relative motion is complete in ever>' case. It is the shrinkage
of the base plate of his apparatus which may come into
play; and, besides improving the apparatus by increasing the
sensitiveness, he has changed the material of this plate from
iron to wood. There is still absence of any indication of
relative motion of earth and ether, and the proportional
shortening must therefore be the same as in the previous
experiments.

It may at first sight seem unlikely that two such different
materials should be equally affected. But the true explana-
tion must be that it is not the nature of the molecule (or
molecular aggregate) or even that of the chemical atom which
determines it ; for these are v'cry different in the two cases.
It is something more fine grained than these, and this some-
thing must be essentially identical (at any rate as far as this
particular property goes) in both these bodies. In fact, the
result is an additional piece ot evidence in favour of the
theory that all atoms are built up of smaller particles, each
one of which is of the same kind.

A New Interrupter.

Workers with induction coils know too well the trouble
there is with the interrupter, whatever its type. The difficulty
is to a very large extent removed in the Grisson Resonance
Apparatus which is put on the market by Messrs. Isenthal
ana Co. The intermittence of the current in the primary
coil is produced by means of a modified commutator which
is spun round by a :}H. P. electric motor. The commutator
interchanges, with a frequency up to 200 times a second, the
connections of the armatures of a condenser with the primary
coil and battery (or nfhrr ';nirlirectional source) which are in
series with it. .\' 1I the battery sends through the

coil a quantity i:qual to twice the maximum

charge of the c.i : these impul.scs must always go

the same way throuj;h th'j primary. Since the current into
the condenser rises ver>- fast (owing to the small inductance of
the primary) and then falls off much more gradually, the quan-
tity that flows through the secondary is nearly, if not perfectly,
unidirectional and hence is suitalile for exciting .\-ray bulbs.
The essential reason of the efficiency of the commutation
arises from the fact that the reversal takes place when the
current into the condenser is zero, or at any rate very small ;

in consequence there is absolutely no visible sparking at it.
This is the case through the whole working range of speed, for
it is at most the tail end only of the flow th-it is cut off.

Instead of commutating the condenser it may be the battery
that is so treated. The flow through the primary is then
alternately of opposite .signs, and the flow through the
secondary is also alternating. In this case by suitably choos-
ing the inductances, the condition of resonance mav be set
up at particular .speeds. In fact, by this means from the
primary circuit alone, an c.m.f. of much higher than 100 volts
can be obtained by the use of a 100-volt circuit.

The condensers employed are electrolytic condensers consist-
ing of aluminium plates immersed in an electrolyte contained
in a seamless steel vessel. Iiach of these is capable of furnish-
ing a current of 15 amperes from a :io-volt lighting circuit.
Greater currents can be obtained by connecting a number in
parallel. Such condensers arc very comp.ict, the dielectric
being the thin film of aluminium oxide which forms on the
plates.

When the coil is replaced by a suitably wound electro-
magnet a powerful alternating magnetic field is produced
which acts on the nervous system. If the forehead is placed
close to one of its poles a flickering sensation of light is
experienced.

The spinning commutator is made in a thoroughly work-
manlike way ; its design is of an engineering type contrary to
what is only too frequently turned out by instrument makers.

ZOOLOGICAL.

By R. Lydekker.

The Smallest British Dinosaur.

The Dinosauri.in reptiles — both small and gic.it — appear to
be attracting a considerable amount of attention at the present
time. One of the latest contributions to the literature of the
subject is a note in the May number of the Gcoh>f;ical Ma-^azine,
by Baron Francis Nopcsa, on the skull of llyf>silof>hotioit, a
species from the Wealden of the Isle of Wight, of about the
size of a fox. ana it not actually the most diminutive, at all
events one of the smallest representatives of the group. De-
spite its diminutive size, it appears to have walked on its hind
legs after the fashion of its gigantic cousin, the iguanodon, of
the same epoch. In a specimen preserved in the British
Museum, Baron Nopcsa shows that what had been taken for
the skull of the creature is really its lower jaw, and that the
structures described as bony plates from the white of the eye
are really the teeth. Consequently, there is every reason to
believe that all dinosaurs, like their relatives, the crocodiles,
lacked a ring of bony plates in the white of the eye.

The English Wa-ter-Shrew.

Captain Barrett-Hamilton, in a recent issue of the Annals
and MaKazinc of Xaltiial History, points out that the British
representative of the water-shrew differs from the typical con-
tinental form of that animal to an extent sufficient to permit
it to rank as a distinct local race, for which the name Scomys
foiliens ciliatiis is available. There are likewise several
continental races of the species, the Scandinavian, ^nd other
mountain forms, in common with the one from the British
Islands, being dull-coloured creatures, in comparison with
those inhabiting the lowlands.

Fa.ce-gland Vestiges in the Horse.

In a paper published in the May nuiiibei- of the .\iiiiiih and
Maijazinc of .Wilunil History, Mr. R. I. I'oeock considers that
the depression so frequently found in the skulls of Arab
horses and thoroughbreds, immediately in front of the eye, has
nothing to do with the face-gland of the extinct hipparions,
but is merely for muscular attachment. If this be so, the
theory as to the importance of this depression in regard to
to the origin of Arabs and tlioroughbreds is wiped out at one
stroke. Despite the fact that the existence of functional
face-glands has been recorded in two living horses, the author
considers himself justified in stating that the modern horse
nc\'er exhibits any trace of the hipp.-irion's f.ice-gland.

July, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

161

Photography.

Pure arvd Applied.

By Chapman Jonks, F.I.C, F.C.S., &c.

Inlensificatton with Chroiniiim Sa//s. — The method of
intensification referred to in the " Science Year Book "
;is having been recently suggested by Mr. J. S. Teape
and by Messrs. Welborne Piper and D. J. Carnegie,
has been further examined by the latter gentle-
men. The process consists in rehalogenising the
silver image by means of a solution O'f potas-
sium bichromate containing hydrochloric acid,
cuid then reducing the silver salt formed with
a developer. The apparently anomalous result
that the image is so made much more dense is due. as
might have been anticipated, to the deposition of a
chromium compound, produced doubtless by the reduc-
tion of the chromate by the metallic silver. This is a
clear guide to the precautions that are necessary to
ensure success, and accounts for the very different re-
sults that different formulae give — from nothing up to
a very large gain in density. Messrs. Piper and
Carnegie in their last communication (" Amateur
Photographer," XLI., 453) recommend potassium
bichromate 10 grains, hydrochloric acid (s.g. 1.16) 5
minims, and water to one ounce, as the most generally
useful bleaching solution, an increase in acid diminish-
ing the increase of density, and a smaller quantity
(preferably with dilution of the solution) increasing it.
.Amidol is preferred to other developers because it is
rapid in action and needs little or no alkali.

The authors consider this process far preferable to
any mercury process, including even the mercury and
ferrous oxalate method. Here I must join issue with
them, and for two distinct reasons, either of which
would, in my opinion, be sufficient to establish the
superiority of the mercury and ferrous oxalate method.
In the first place, the chromium compound that is
added to the image is soluble in acids and is produced
always in an acid solution. So far as at present
known, the presence of a solvent of the material that
constitutes the image renders the production of the
image uncertain. That is, one cannot be sure of the
same increase of density following the same procedure
so far as one is able to make it the same; and one can
never be sure that the presence of the solvent does not
lead to a reduction effect on the image, and if it should
do so it is scarcely possible for it to be proportional
throughout. The mercury and ammonia method has
a solvent present, namely, the ammonia, and this
method never gives a proportional result. Then,
secondly, the material added to the image has a
" brownish buff " colour, according to the authors, and
this is very much the colour that one would expect the
chromium compound to be. It is always undesirable
to introduce a coloured substance into a negative, be-
cause a coloured image will produce different results
according to the colour sensitiveness of the printing
paper, and also, it may be added, according to the nature
of the light used. A neutral tinted image graduates
all lights alike, but it is practically impossible to calcu-
late the effect of a coloured image. Therefore it seems
to me that while other methods have advantages in
special cases and are good enough for negatives that
have no particular value, the mercury and ferrous
oxalate still remains the only scientifically reliable
method of intensification.

Reductinn with Cobaliic Salts. — Mr. Harry E. Smith
(jour. Royal Phot. Soc, May, p. 185) has been
experimenting with certain ammonio-cobaltic salts and
analogous compounds as reducers for negatives and
silver prints, and finds that the tetra-ammonio-cobaltic
potassium nitrite, a salt prepared by Erdmann a genera-
tion or so ago, is the most satisfactory of those he has
tried. Erdmann's salt will shortly be on the photo-
graphic market, its use as a reducer having been
patented. The formula suggested is a quarter per
cent, solution of the salt in a seven or eight per cent,
solution of sulphuric acid, and the negative or print
after reduction is soaked for three minutes in a ten
per cent, ammonia solution, and finally washed. Mr.
Smith claims for this reducer that it attacks the
" denser deposits of silver much more readily than the
half-tone and lighter deposits, so that it is particularly
useful in softening the scale of gradation of hard nega-
tives or prints." It appears to be distinctly slow in
action, from Mr. Smith's communication it is not
clear whether what he calls its " selective " action, that
is, the fact that it does not attack the thinner deposits
unduly as most reducers are liable to do, is due simply
to the slowness of the action or to some peculiar
property wherein it may be likened to the persulphates.
If the latter is the case, then an investigation of the
chemistry of the change during reduction may be of
considerable interest as helping to show why the per-
sulphates produce exceptional results, for we do not
yet know what the action of the persulphates is from
a chemical point of view. I consider that in all cases
we ought to know the chemistry of such changes as
these before trusting valuable negatives to the action
of the proposed reagents. Of course, negatives
that ha\e no permanent value do not require
such consideration. I hope that Mr. Smith will give
us the results of further investigation, and determine
the character of the brownish substance that is some-
times obvious after reduction, and for the removal of
which the ammonia bath is desirable.

The Stability of Photographs. — The action of light
and air upon photographs is often regarded from a too
empirical point of view, its effect being judged of
merely by the visible change that results. I-ight, in
some cases, causes a loss of colour or bleaching, as in
the fading of dyes that is so obvious in curtains, car-
pets, clothes, and dyed fabrics in general; and in others
a production of colour as in some methods of photo-
graphic printing. If the simple object is either to
bleach or to produce colour, then, of course, the ob-
servation of the colour-change may be a sufficient guide
to the progress of the action, but if the aim is to test
for stability, neither the presence nor the absence of a
visible change is sufficient to justify any definite con-
clusion. There may be even much alteration in ap-
pearance while the image renrains unaffected, as in the
case of platinum prints carelessly made or pasted on to
inferior mounts; and on the other hand, there may be
considerable change that is not manifested by an\
notable alteration in either tint or depth of colour.
The only way to settle such questions is to investigate
the composition of the image by chemical means as
well as its appearance by optical means.

Correspondence. — Bryan, E. H. — Tlie method of
development you propose would not be advantageous
for seveial reasons. The practical aspects of photo-
graphy during the visit of the British Association to
South Afric-a will be dealt with in the special nun-.ber of
this journal that will shortly be issued.

l62

KNOWLEDGE \- SCIENTIFIC NEWS.

rjii.v, 1905.

Conducted by F. Shillington Scales, f.r.m.s.
R^oyal Microscopic a.1 Society.

May i;th. — Al jo, !^;lIK>\^■r Square. Dr. Dukintifld 11.
Scott, F.R.S., President, in the chair. Mr. Roiisselet
described an old microscope of the Culpeper-Scarlet
type which had been presented to the Society by Mr. J.
L. Hazelwood. It was sigrned " Xath. Adams, Optician
to his Koyal Highness Frederick Prince of Wales
l-'erit." The date was probably about 1740, and it
differed from others of the type in having- four pillars
instead of the usual three. Mr. Rousselet also de-
scribed an old Adams I.ucernal microscope, made b}
Adams' successors, W. and S. Jones, which had been
presented to the Society in January by Lieut. -Col.
I'upman, and was exhibited in the room. The body
consisted of a mahogany box of the form of a frustum
of a pyramid about 17 ins. long and 7 ins. square at the
base lying horizontally. The objective was carried in a
sliding lube at the small end, and an eye-piece of two
lenses about 5 ins. in diameter was placed at the other
end. The stage had vertical and horizontal motions,
and there was a condensing system of two independent
lenses behind it. The curious feature about the instru-
ment was the method of observing the image, which
was by means of an aperture about ;j in. in diameter ni
a small disc carried by an arm that was attached to a
telescopic rod projecting from below the instrument
The distance of the disc from the eye-piece could thus
be adjusted until the best effect was obtained. On
looking through the disc, which in this instance was
about 14 ins. from the eye-piece, a very fair image of
an object placed on the stage was seen in the eye lens.
A communication received from Mr. D. D. Jackson, ,)f
New York, on " The .Movements of Diatoms and other
.Microscopic Plants," was read. Mr. Jackson described
the interesting observations and ingenious experiments
made by him, some with artificial diatoms, which led
iiim to conclude that the movements referred to arc
caused by the escape of oxygen gas evolved in these
organisms. Slides of Oribalidae were exhibited from
the collection presented to the Society some twenty
years ago by Mr. .\. 1). Michael, who, on the invitation
of the President, made some remarks upon that family
of the Acarina.

The Microscope in the Witness Box.

Ihe usi- cil llie niir:r(iscope as an aid to tin- m iuuliln
worker is .ipp.irent to everyone, and it is, ol c<jurse,
universally used in scientific laboratories. It will occur
Jo most people that it must have many uses as a means
of detecting adulteration in food, and that, therefore,
it is a valuable aid to the public analyst, but it is,
perhaps, not so evident that it can give equally valuable
help and testimony in the witness box. An elementary
example of the help given by the microscope in forensic
medicine is its use in detecting blood stains. The
minute red blood discs which give the red colour to
the human blood are not more than seven one-thou-
sandths of a millimetre in diameter, and are obviously

microscopic objects, w^hile they can only be seen in un-
dried blood, but the microscope can be used to give
evidence of blood stains in quite another way. Suspected
bloodstains on clothing, etc.. can be treated with a little
alkali, evaporated to dryness, and then heated with
acetic acid and a minute amount of sndiuni chloride,
witli tlif result tliat sniaii Init cliaractoristic crystals.

known as " haemin crystals," make lliiir appearance.
(Fig. I, much magnified.)

This, however, is more an example of laboratory
work than of a demonstration in open court, but some
verv striking examples of what can be shown by the
microscope in cases of suspected forgery were given
by Mr. .Albert S. Osborn a year and a half ago, in what
was unfortunately the last number of the American
Journal oj Applied Microscopy, and I reproduce some of
his excellent illustrations here because they will, 1 think,
interest readers in this country who have not seen the
original paper, expressing my obligations to Mr.
Osborn for both illustrations and subject matter.

For instance, as .Mr. Osborn points out. il is
manifest that if .1 paper were folded, and it could be
demonstrated that part ol the writing was made after
such folding, strong suspicion would be cast upon the
docimicnt. 'ITiis might be shown by a liny
amount of ink spreading into the crease and c\ en reach-
ing the other side of tin- paper, and it would be f|uite
unmistakable.

Similarly, fr.audulent additions to documents may be
shown to have been written with a different pen, or at
a different tiine, or under different conditions, by
measuring the width of the unshaded strokes and
observing that they differ from those of the original
writing. .Such measurements arc readily made up in
the ten-thous.indth of an inch, or less.

July, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

163

Still more striking- are additions made to letters as
in Fig-. 2, where the numeral I in II has heen changed
mto 7 by the addition of a stroke at the top.

A fraudulent addition or interlineation may touch the
top of another letter and thus give evidence against
itself. In Fig-. 3 it will be seen that the words " in full

.111 i !-<-( ^ ti'rinPP'

to date" have been manifestly added after the signa-
ture of the receipt, as shown by the cros.sing of the "t"
in "date" running over and into the top of the initial
letter of the signature. In this case the whole question
was whether the receipt was given for a definite amount
or " in full to date."

Forged signatures are frequently first carefully out-
lined in pencil before being inked in. In such cases the
pencil marks can be shown under the microscope not
properly covered, and with the graphite caught in the
ink film. Any further attempt tO' erase the pencil marks
would probably have more or less altered the superficial
appearance of the paper. Forged signatures carefully
and laboriously drawn from a model with frequent lift-
ing's or slopping-s of the pen show the over-lapping of
lines and uneven distribution of the ink with astonishing
clearness. The tint also of the ink may show on com-
parison that a document purporting to be several years
old is really only as many days old. Even in type-
writing:, comparisons by means of the microscope may
show numerous discrepancies and differences.

r-crforations are often used to prevent fraud, Inil
these have been known to be laboriously filled in and
new ones made. ITie microscope, however, readily
exposes such a fraud, as is shown in Fig. 4.

•«

•••

•

• • #

" %: ■■

' 'i''^

'*L^

■" •

« •

' ■ -f . ■■;

#•;•-»

•3#

*«

1..*.

v«

Mr. Osborn calls attention to the fact that high
powers are not necessary to detect the majority of such
cases of alteration of documents. .'\ f; in. is about as
high a power as is needed, but there must be good subr
stage illumination bv means of a condenser, and means
of illuminating opaque objects by a bull's-eye or other
wise. Polarizing prisms may be useful in certain cases
1)1 paper fibre examination, and micrometer apparatus
is essential, as well as drawing apparatus. Photo-micro-
graphy is of most valuable service in making exact re-
productions.

The microscope should have a large stage, and for
examining: some kinds of disputed documents the micro-
scope tube may be mounted with advantage on a special
stand witliout a stage, so as to give a largfe open field
directly under the objective. In this way it is easy to
examine the middle or any other part of a large docu-
iiienl. The examination of crossed lines, traces of
pencil marks, edges of lines, paper fibres, etc.; the inves-
tigation of evidences of re-touching, and the examina-
tion of ink conditions may require a higrh power objec-
ti\e, but lor examining" writing as such a mag-nification
nl Irom ten to fifty diameters is ample. Photo-micro-
graphs arc freqLiently useful, and may, in certain cases,
be c<niclusi\e c\ idence. The general magnification of
such photo-microg;raphs is from twenty to fifty diame-
ters, l>ut the objective must be flat in the field and a long
camera length is preferable to eye-piecing. A camera
lucida attachment for drawing directly from the image
in the microscope is useful for making illustrations and
outlines, and in measuring.

Objectives witK Sa.fety Springs.

Beginneis and elementary students find the very
short working distance ol high power objectives
a source of dang-er either to the front lens of the
objective Or to the cover-glass of the slide, and even
more experienced workers are sometimes liable to mis-
fortunes of this nature. To- obviate this C. Reichert has
fitted Bourgnet's Spring Safety Action to all his high
power objectives from J in. upwards. The optical part
of the objective is mounted in such a way as to slide
bodily within an outer projecting case, the front lens
projecting throug-h a circular aperture in the front of
this case and kept in position by a spiral spring- above,
which rests against a collar inside. Under ordinary cir-
cumstances the elasticity of this spring keeps the objec-
tive in proper adjustment, but in case of contact between
lens and cover-glass the optical part is pushed into its
sheath.

Hanging Drop Prepa.rations.

Mr. j. K. Collins gives in the British Medical Journal
a very simple method of making- a hanging;-drop pre-
paration which obviates the usual method of building
up a moist cell with rings of wet blotting--paper. A
small rubber elastic band of suitable size and thickness
is smeared with vaseline on one side, and this side is
then placed on the .slide. The upper side of the rubber
band is now likewise smeared with vaseline and the
cover-glass with its hanging-drop applied to it. An air-
tisrhtcell is thus easilv made.

[Communications and enquiries on Mieroseopieal matters are invited
and should be addressed to F. ShiUington Scahs. "Jersey,"
St. Barnabas Road, Cambridge.]

iG4

KNOWLEDGE & SCIENTIFIC NEWS.

[Jriv, 1905.

The Folcc of the Sky
for July.

By \V. Shackleton, F. R.A.S.

The Sux. — On the ist the Sun rises at 3.^8, and sets at
■S.18 ; on the 31st he rises at i.23, and sets at 7.49.

The earth is at its greatest distance from the Sun on
the 3rd, when the apparent diameter of the Sun is a
minimum, being 31' 3o"-7.

Solar activity is well shown by the large number of
sunspots and bright prominences.

The position of the Sun's axis and equator, re(]uireJ for
physical observations of the Sun, is indicated in the fol-
lowin'' table :^

J-. Axis inclined from N.
point.

Equator S. of
Centre of disc.

July . .. 2''43'W.
„ 10 .. 1° 23' E.
., 20 .. 5° 51' E.
.. 10 .. 10° 6' E.

3° 3'

4° 0'
4° 56'
5° 45'

The Moon : —

Date. Phases.

H. M.

July 2 .. 9 New Moon
,, 9 .. J) First Quarter
,. 16 .. 0 Full Moon
,, 24 .. d Last Quarter

July 10 .. Perigee 229.700 miles.
„ 23 .. Apogee 251,200

5 50 p.m.

5 46 p.m.
3 32 p.m.
I 9 p.m.

3 oa.m.

6 30 p.m.

OccuLTATioNS. — There are no stars brighter than the
fith magnitude occulted during this month, as seen from
Greenwich.

The Planets. — Mercury is an evening star in Gemini
and Cancer, but is not favourably situated for observation
during the early part of the month ; towards the end of
the month he is approaching an eastern elongation from
the Sun, but even then he only sets one hour after
sunset.

Venus is a bright object in the morning sky, looking
east, rising about i.io a.m. on the 15th; as seen in the
telescope the phase appears that of " half moon," the
apparent diameter of the disc being 22". Towards the
end of the month the planet is skirting the northern
boundary of the Hyades.

Mars is on the meridian just before sunset, but on
account of increasing distance from the earth his lustre
is diminishing. The planet is not well placed for obser-
vation on account of his great southerly declination, and
as this is increasing his meridian altitude is becoining
less. The apparent diameter of the planet is 12" and
the disc is slightly gibbov.s, o-SS being illuminated. f)n
the 15th the planet sets about 1 1.35 p.m.

Jupiter is a morning star in Taurus, and is situated a
few degrees south of the Pleiades; on the 22nd he rises
about midnight. On the 3rd and 4th, Jupiter and N'enus
will form a brilliant pair in the morning sky, being less
than 3 apart, Jupiter being to the noith. The apparent
polar diameter of the planet is 33".

Saturn is coming mto a more suitable position for ob-
servation m the evenings; he rises about 10.50 p.m. on
the ist and about 8.40 p.m. on the 31st. Near the
middle of the month the planet is on the meridian about
2.40 am.; he is describing a short retrograde path near
cr Aquarii.

We are looking down on the northern surface of the
ring at an angle of 9", and the apparent diameters of the
outer major and minor axes are 43" and b"-^ respectively,
whilst the polar diameter of the ball is i7"-o.

Uranus is becoming more favourably situated for ob-
servation at convenient times, being on the meridian
about 10.30 p.m. on the 15th. Me is situated about 2^'
south of 41 h magnitude star m Sagittarii, and can easily
be seen with an opera glass, though somewhat difficult to
see with the naked eye.

Neptune is out of range for observation.

Meteors. — The most conspicuous shower is the * Aqua-
rids, which occurs on the 28th ; they are slow moving
and long. The radiant is situated in R..^. XXll.'' 6"",
Dec. S. II'.

Telescopic Objects : —

Double Stars. — 5 Serpentis, .W.'^ 13'", N
mags. 5-1, 10; separation 10".

/i Serpentis, XV.'' 41™, N. 15" 44', mags,
separation 31".

e Serpentis, X\'III.'' 51'", N. 4° 4', mags,
separation 2i"-6. Both are yellow, the priinary being of
a paler yellow than the smaller star.

t Cephei XXII.'' i"", N. 64° 8', mags. 4-7, 7; separa-
tion 6".

S Cephei XXII.'' 26"', N. 57'^ 56 , mags. 4-2, 7; sepa-
ration 40". A pretty pair for small telescopes, yellow
and blue. It is also a variable star; period 5'' g"", with a
quick rise to maximum in i"" 9I1.

Clusters. — M5 (Libra). A compact cluster situated
about one-third of a degree north of the double star
5 Serpentis; when seen through a pair of opera glasses
it appears like a large nebulous star.

N.G.C. Oi(>ii- Cluster in Serpens. About one-third
of the way between 9 Serpentis and a Ophiuchi (visible
to the naked eye).

2° 13',
3-8, 10;
4-0, 4-2;

New Preservative for Animal Products.

Mr. Fletcher, chemist and analyst of .Sydney. Xcw
South Wales, has during recent years introduced a new
process for preserving meats and other organic sub-
stances. The food products are placed in an airtight
chamber, and treated by a gas for six or eight hours.
Xo liquids or solids come into actual contact with the
meat. .An unskilled workm;m can operate the chamber,
and the cost is said to be very small. It is further
.illeged that no ta.stc from the curing prwess has yet
been noticed, and no analyst has discovered any pre-
servative whatever in the goods cured. Beef up to
the present has not been cured satisfactorily, and the
process is not effcctu.'il with fruit or milk, hut success
is claimed for the treatment of mutton, bacon,
sausages, &c. The treatment is simple and rapid. No
freezing is necessary, and no borax or kindred preser-
vatives, and it is staled that food after treatment can
he shipped in safety and remain in a fresh condition
during franspf.rf. Since the latter part of 1902 it is
staled that the process has been tested continuou.sly,
and that meat, sausages, kc. cured by it in April, 1903,
arc still .sound ;md good.

1^5

KDomledge & Seientifie Hems

A MONTHLY JOURNAL OF SCIENCE.

Conducted by MAJOR B. BADEN-POWELL, F.R.A.S., and E. S. GREW, M.A.

CONTENTS AND NOTICES.— See page V.

THE BRITISH ASSOCIATION.

MEETING IN SOUTH AFRICA.

Professor George Howard Darwin, who, on August 15,
at Cape Town, will be installed President of the British
Association for the Advancement of Science, in succes-
sion to the Right Hon. A. J. Balfour, M.P.,isthe second
son of the late Charles
Robert Darwin, the eminent
naturalist — the " Copernicus
of biology." Born in 1845,
at Down, the Kentish home
of the Darwins, he entered
Trinity College, Cambridge,
and in 1S6S he graduated
as Second Wrangler and
Second Smiih's Prizeman.
In the same year he was
elected Fellow of his College,
and in 1883 was elected to
the Plumian Professorship of
Astronomy and Experimen-
tal Philosophy in the Univer-
sity of Cambridge, vacant by
the dea'h of the Rev. James
Challis, M.A.,F.R.S., a posi-
tion which he still holds.

One of the earliest of Pro-
fessor Darwin's contributions
to science appeared in the
"Philosophical Transactions"
entitled " On the Influence of
Geological Changes on the
Earth's Axis of Rotation " ;
his most recent was read

before the Royal Society on May 18 — " On Lesage's
Theory of Gravitation and the Repulsion of Light." In
a series of papers he has dealt exhaustively with the
theory and prediction of the tides, especially with refer-

his studies will, however, be manifest in his Presidential
Address. This will discuss the general principles in-
volved in theories of evolution, with special reference to
the world of inanimate matter, and will be illustrated by
means of various theories
of the intimate constitution
of matter and of cosmical
evolution.

Professor Darwin has been
honoured by many scien-
tific societies both at home
and abroad. In 1879 he was
elected a Fellow of the Royal
Society, receiving in 1S84
the Royal medal of that body,
the grounds of the award
being his mathematical in-
vestigations of the secular
changes in the relative mo-
tions of the earth, moon, and
sun, due to interna! consump-
tion of energy ; and for
work on the harmonic
analysis of tidal observations.
He is a Foreign Member of
the American Academy of
Arts and Sciences, and of
the Reale Accademia dei
Lincei, Rome ; and an Hon-
orary Member of the Uni-
versity of Padua. The latest
recognition of his position
in the world of science was that afforded by the confer-
ment of the degree of Doctor of Science, honoris causa,
at the Encffinia, Oxford University, on June 28 last,
when he was admitted with the significant salutation,

DARWIN, LL.D., r.R.S.,

ence to Indian tidal observational work. The trend of " Docta docti progenies patris."

1 66

KNOWLEDGE & SCIENTIFIC NEWS.

[July, 1905.

The British Association:

ITS ORIGIN AND PROGRESS.

Objects of the Association.— To give a stropser impulse
and a more systematic direction to scientific inquirj' —
to promote the intercourse of those who cultivate
Science in different parts of the British Empire with
one another and with foreign philosophers — to obtain a
more general attention to the objects of science, and a
removal of any disadvantages of a public kind which
impede its progress.

The British Association for the Advancement of Science
is something more than an asset of English science;
it may now he truly ranked as an asset of the British
Empire. Thus it would seem to have fulfilled the aspira-
tions of those, its founders, "merchants of light," if
we m:iv u^e the term, who cherished a far-seeing vision
of ultimate growth and power. \Ve may, however, be
sure that none ever dreamed that the peripatetic habits
of the .Association would extend to so remote a centre
as South .\frica, now, moreover, an integral part of the
King's dominions.

The story of how the Association sprang into exist-
ence, and what it has effected, is, or should be, a
f.nmiliar one to Englishmen, for the history of the
British .Association during the seventy-four years of its
hardy life is in no small degree the history, not only of
the progre.ss and range of scientific enquiry in the land
of their birth, but a commanding record for an equiva-
lent period of personal achievements. To emphasise
this it will suffice to recall such names as Brewster,
Sedgwick, Murchison, Owen. Lyell, Faraday, Joule.
Darwin, Hooker (happily still among u.s), Thomson
(Lord Kelvin'), Stokes, Tyndall, and Huxley, each ol
whom has given us abiding and profound conceptions
in science and the problems of life. .Surely every school-
boy in England might find a text of instruction here !

On two previous occasions only has the Association
migrated from the Mother Country in order to hold it.s
annual Congress. The first of these was in 1884 when
it crossed the Atlantic to meet at Montreal. Lord
Rayleigh occupied the presidential chair, and there wa.«;
- 1 n'tr 'id.-iiif f of 1.777 persons. To signalise the event,
the British Association instituted in McGill L'nivcrsity
a prize medal for work in applied science, the obverse
of which, it is of interest just now to chronicle, bears
the head of James Watt; the reverse has a wreath of
maple and rose leaves. With this precedent in mint),
South Africa may possibly desire to receive a similar
record of the present visit.

In 1897 the Association visited Toronto, having .Sir
John Evans as President. Here the attendance reached
1,362.

The idea of the British Association as an amalgama-
tion of scientific interests is clearly set forth in a letter
addressed by Sir David Brewster in 1831 to Mr. John
I'hillips, [-".fiS., the Secretary of the Philosophical
.Society of York, and although this has been commented
on in all its bearings before now, it will bear recapitula-
tion, more especially at a moment when the Association
is breaking fresh ground and is grasping the hands of
new friends.

Subjoined is the letter referred to : —

Allerby, by Melrose February 23rd, 183 1

"Dear Sir,— I have taken the liberty of writing to you on
a subject of considerable importance. It is proposed to

PROF. A. R. FORSYTH, F.R.S.

Prof. Andrew Rvssell Forsyth, Sntlkvian Profeseor of Pure Mathematics
io the University of Cambridge, is President of Section A, Mathematical and
Physical Science. He is the author of many treatises en subjects of
mathematical analysip, and is a Rojal Meda'l'st of the Uoyal Soc'ety.

MK. O. T. HKIl-UY, F.C.S.
Mfi. Oroiiok TiinMAH*BK.iLuv,oI OlatiKOw, Prcsidentof Section B, (.:heiiiiHtry,
is a past presi lent ol the Society of Chemical Industry, and an authority on
chcmintry aa apiilicd to the arts 'of life. Ha has siiccially studied the industrial
aspecta of fuel supplies, and is the compiler of a ** Review of the Coal Con-
sumption of the United Kingdom." Among his recent papers are : " Tho
Position of tho Cyanide Industry " ; " Tho IntefiHincalion of Chemical Action
hy the Emanations from Gold and Platinum " ; and *' PliosphorescencA caused
by the Beta and Qamma Rays of R idium "

July, 1905.J

KNOWLEDGE & SCIENTIFIC NEWS.

167

PROF. H. A. MIERS, F.R.S.

Prof. Henry Alexander Mierr, Waynflete Professor of Mineralogy in
the University of Oxford, is President of Section C, Geolrgy. Formerly he
was an Assistant in the Department of Minerals, Brit'sh Museum (Natural
History). He is Ihe author cf many memoirs in mineralogy and crysta'-
lography.

MR. O. A. BOULENaER, P.R.S.

Mr. George Albert Boulenoer, of the Department of Zoology, British
Museum (Natural History), is President of Section D, Zoology. He is the
author of reference works on Batrachia, Lizaa-ds, Chelonians, and Crocodiles,
and is an authority on the fishes of Africa.

establish a British Association of Men of Science, similar to
that which has existed for eight years in Germany and which
is now patronised by the most powerful sovereigns in that
part of Europe. The arrangements for the first meeting are
in progress, and it is contemplated that it shall be held in
York, as the most central city of the three kingdoms. My
object in writing to yon at present is to beg that yon would
ascertain if York will furnish the accommodation necessary
for so large a meeting, which might perhaps consist of 100
individuals; if the Philosophical Society would enter zealously
into the plan, and if the Mayor and influential persons in the
town and in the vicinity would be likely to promote its objects.
The principal objects of the Society would be to make the
cultivators of science acquainted with each other; to stimu-
late one another to new exertions; to bring the objects of
science before the public eye, and to take measures for
advancing its interests and accelerating their progress. The
Society would possess no fund, make no collections, hold no
property, the expense of each anniversary meeting being
defrayed by the members who are present.

" As these few observations will enable you to form a
general opinion of the object in view, I shall only add that
the time of meeting which is likely to be most convenient would
be about the iSth or 25th of July.

" I am, dear Sir,

" Ever most truly yours,

" D. Brewster."

"J. Phillips, Esq."

The Philosophical Society and the civic authorities
of York viewed the proposition with every mark of
favour, and it was arranged that the inaugural meeting
of the Association should be held in the Yorkshire
Museum on Tuesday, September 27, 183 1, the first
President to be Viscount Milton, F.R.S. At this
gathering the admirable Statement of Objects, drawn
in almost identical terms with those which appear at the
head of this notice, was unanimously adopted as Iho
mitial propaganda of the Association, and thus it
remains to-day.

The second President of the Association was the
Rev. William Buckland, D.D., F.R.S., Professor of
Geology and Mineralogy in the University of Oxford,
and the meeting took "place in that city. It has been
chronicled by one who. was present that Buckland was
the life of the whole assembly. Curiously enough no
numerical record seems to have been kept of the
attendance of members. The third meeting was held
under the patronage of the sister University, Cam-
bridge, the Rev. Adam Sedgwick, F.R.S., presiding,
after which Edinburgh and Dublin had their turn and
the Association was then fairly launched.

It would be tedious to detail the successive doings of
the Association year by year, or relate how it has
gradually grown in power and usefulness. Annually
some suitable provincial town is chosen as the venue,
and one visit does not preclude another. But the
Association never meets in London. The Presidents
have always been selected with a real regard to the
position and authority they hold in the branch or
branches of science they represent, and it is to this
jealous care that much of the repute the Association
now enjoys is due. Then, too, their addresses in them-
selves furnish an epitome of the progress of science.
Nor should the loyal services of the General
Officers be overlooked ; some of them, indeed,
will be seen to have directed the helm of affairs for long
periods. Incidentally it may be mentioned that His
Royal Highness the Prince Consort was President of
the meeting held at Aberdeen in 1859.

The work of the British Association is carried on in
( eleven Sections, which represent, as it were, the cycle

1 68

KNOWLEDGE & SCIENTIFIC NEWS.

[July, 1905.

of the sciences. Each has its own president for the
time being, and the " Transactions " of these Sections,
tr^ether with the '' Reports on the State of Science "
and Presidential addresses constitute the contents of the
invaluable scries of vohimes which have been issued
without break since the year 1833, the first date of
publication.

.'\s at present constituted the Sections comprise the
following divisions: — .\, Mathematical and Physical
Science; B, Chemistry; C, Geology; 1), Zoology; K,
Geography; F, Economic Science and Statistics; G.
Engineering; H, Anthropology; I, Physiology; K,
I?otany; L, Educational Science. The employment of
alphabetical letters to distinguish the Sections was
introduced in 1835.

The discussions on scientific questions which annually
take place in the Sectional Committees were regarded
from the first as calculated to fo.ster and strengthen the
spirit in which the .Association was conceived, as well
as exemplifying its principles. But the enormous ex-
tension in the boundaries of science which the past fifty
years has witnessed has naturally brought in its wake
an enlarged platform for the stream of criticism and
comment. This development has, indeed, suggested to
.some of the veteran habitues of the meetings that there
is now, perhaps, an over-expression of opinion, and they
recall with lingering regret the notable a.ssemblages of
a brilliant, if small, band of scientific expositors, whose
personality was the focus of the gatherings; their
flights into the whirlpools and rapids of argument 01
conjecture, a keen and satisfving experience. But
without "talk" the modern Congress would die of
inanition; it is, in short, a safety-valve that had best
be left untouched.

Since 1867 an interesting and popular feature of the
meetings has been the delivery of a lecture on some
particular scientific subject, designed especially for an
audience of working-men. The first of the series was
given by John Tyndall, on " Matter and Force," and
at last year's Cambridge gathering there was a discourse
on " The Form of Mountains."

In 1884 a "Corresponding Societies Committee" was
instituted with the view of encouraging the affiliation
of local Scientific Societies in order that they might be
formdiy in correspondence with the Association, and
thus assist in promoting its objects. At present 72
local bodies constitute Corresponding Societies, but it
is hoped that this relatively small number will steadily
increase.

No outline of prioress should, however, omit to
mention the money grants which the Association has
bestowed from its necessarily limited funds in further-
ance of scientific purposes. The grand total of such
sums allotted since the year 1834 amounts to no less
than ;{5'68,300.

Our survey, brief though it is, will, perhaps, serve
to indicate the plan and general scope of the organisa-
tion, as well as the fruitfulness of its career.

It stands to-day, as in the past, moved by no adver-
tisements or trumpeting fanfares, or idea of self-aggran-
disement, es.senfially a silent force working with definite
aims and understanding for the advancement of the
several branches of .scientific thought and knowledge
Actuated thus, the Association transplants its standard
to .South Africa, a step bold and far-seeing enf)Ugli
to command a common approval, as also it enlists
our brightest hopes for a successful and prosperous
gathering.

In Jf.iiiIKf F.ir.l

5IR W. J. L. WHARTON, K.C.B., F.R.S.

RFAit-AnMiiuL Bill Jamks Li.oyd WiiAnTON, till lately Ilydrogrftplicv of the
ry, is President of Section E, Geogrfipliy. He lm.s had charge of Surveys in
parts of the world. Author of a work on " Hydrographical Surveying."
In lfl7-l he took part in ohscrvations on the Transit of Venus.

REV. W. CUNNINQHAM.vD.D.

Tnp. llr.v. Dn. CtJKHiKonAM i« President of Section F, Economic Science
and Statistics. Fellow of Trinity College, and r<ady Margaret Preacher.
Sometime Lecturer in Economic Hi«tory, Harvard University. Author o(
" Orowih of Englisli Industry and Commerce in Modern Times," 1901 (3rd cd.l :
"TliB Use and Ahusc of Money'; " Gospel of Work"; "Ancient Times "
"The Path towards Knowledge.'

July, 1905.J

KNOWLEDGE & SCIENTIFIC NEWS.

169

I'ltohibg Mdidhl: Foi.t

SIR C. 5C0TT=M0NCRIEFF, Q. C.S.I.

Colonel Sin C. Scott-Moncrieff, late Bengal Engineers (medal Indian
Mutiny), is Presiflent of Section G, Engineering. He has been respectively
Under-Secretary, Public Works Office, Egypt, anil Under-Secretary for
Scotland. In the former capacity, he carried out important work in con-
nection with Nile barrage. Author of "Irrigation in Southern Europe.'"

nolo hil MmiU i Fox.J

DR. A..C. HADDON F.R.S.

Dr. Alfred Cout Haddon, University Lecturer in Ethnology in the
University of Cembridte, foimeily ProfesEor cf Zcolcgy in the Royal College
of Science, Dublin, is President of Section H, Anthropology. In 1»5. he
went to Torres Strait to investigate. (he structure of the coral reefs, and the
fauna, and also studied the tthnogi-apby cf the Isltnders.

Progracmme of the
Meeting.

On Saturday, July 22, the Durham Castle and Kildonan Caxtlc
sail for South Africa, carrying, respectively, a complement of
loS and 45 members of the Association. On Saturday, July 29,
the Saxon sails with 139 members, who constitute the Official
party, and are the guests of the South African Colonies.
With earlier departures, the total number proceeding to the
meeting will fall little short of 400.

CAPE TOWN. — The Saxon arrives at Cape Town (early
morning) on Tuesday, -August 15, and the work of the Asso-
ciation commences forthwith. A meeting of the Council will
t.ike place at noon, and the 11 Sectional Committees and the
General Committee will also foregather.

The President's Address to the Association will be
delivered (in part) at the inaugural meeting to be held in the
evening.

In this, Professor Darwin proposes to discuss the general
principles involved in theories of evolution, with special
reference to the world of inanimate matter. He will illustrate
the subject by means of various theories of the intimate
constitution of matter and of cosmical evolution.

August If). — Presidential .Addresses to Section A, Mathe-
matics and Physics; Section D, Zoology; Section K, Geo-
graphy ; Section F, Economic Science and Statistics ; Sec-
tion H, Anthropology ; and Section L, Educational
Science.

In the afternoon a garden party will be given by His Excellency
the Governor (Sir Walter F. Hely-Hutchinson) ; in the evening
there will be a reception by the Mayor of Cape Town.

Aiii;iisl 17. — Sectional Meetings.

In tlie evening Prof. E. B. Poulton, F.R.S., delivers a lecture
on ■■ W. J. Burchell's Discoveries in Soutli Africa."

August IS. — Sectional Meetings.

In the evening Mr. C. V. Boys, F.RS.. delivers a lecture on
" Some Surface Actions of Fluids." Following this a conver-
sazione will be given by the combined scientific societies of Cape
Town, at the South African Museum.

In the afternoon, Sir David Gill, K.C.B., F.R S., will give a
reception at the Royal Observatory.

The " Saxon " leaves for Durban [evening).

Ausust 19. — Whole day excursions to, among other places of in-
terest: Table Mountain ; De Beers Explosive Works ; Hout Bay;
Admiralty Works, Simon's Town ; Marine Station, St. James's.

The ''Durham Castle" leaves for Durban direct, arriving in
the forenoon of Tuesday, August 22.

DURBAN.— .-I !/i;;(.s^ 22.— A lecture will be delivered in the
Town Hall in the evening by Mr. Douglas Fresbfield, F.K.G.S.,
on " Mountains: the Highest Himalaya."

In the afternoon a garden party at Sir Benjamin Greenacre's.

August 2,J.— Visit to Botanic Gardens; trip (full day) to Umko-
maas; circular trip round the Bay; inspection of Girls' Model
Primary School ; Mount Edgecombe (Sugar Estate) ; Parade of
Cadets.

KNOWLEDGE & SCIENTIFIC NEWS.

[July, 1905.

^VICTORIA FALLS

iti\er:\py

BRITISH Assoaum
■Route Map-

KIMBCRL'C

BLOCMFONTCIKI

LADYSMITH/
/'';" V VCOLtNSO

PIETERMARIT2BURC/

DURBAN

TABLE OF DISTANCES

Southampton to Cape

Town . . . . 5.97S

Cape Town to Johan-
nesburg .. .. 1,013

Cape Town to Blocm-

foniein . . . . 750

Cape Town to Kim-

berley . . . . by]

Cape Town to Bula-

wayo .. .. 1,362

Bulawayo to Victoria

Falls .. .. 275

PIETERMARITZBURO.— /iKg^Hs/ 2^.— Leave Durban for
Pietermaritzburg, by special trains (momiriK). In the evening,
Colonel David Bruce, C.B.,' F.K.S., will deliver a lecture on
"[Sleeping' Sickness."

In the afternoon, a garden party.

August 25. — Visits to the Museum, Educational Institutions,
and Public Buildings generally.

Excnrsion to Native Location, Henley, with Kafir dance; Govern-
ment Kxpcrimental Farm, Codara ; Government Laboratory, Aller-
ton ; Town bush Valley Nurseries.

August 20. — Leave Pietermaritzburg by special trains for a visit to
Colenso ; sleep in the special trains ; leave for I..adysmith August 27
(Sunday) and visit the town ; depart same day for Johannesburg.

JOHANNESBURQ.— /1m/j»5< 2H.—\n the evening a lecture
will be delivered by Prof. \V. R. Ayrton, F.K.S., on " Distri-
bution of Power."

Auf;ust 2.'>.^Sectional Meetings. Presidential Addresses to
Section B, Chcmi.stry ; Section C, Geology ; Section G,
Engineering ; Section I, Physiology ; and Section K,
Botany. — A Report by Mr. G. \V. Lamplugh, F.R.S., on the
" Geology of the Victoria Falls," will take the form of an
afternoon address to Section C.

In the afternoon a garden party will be given by His Fxcellency
the High Commissioner for South Africa (the Earl of Selborne,
G.C.M.G.); in the evening, a reception by the Mayor and Town
Council of Johannesburg.

August 30. — Sectional Meetings (morning); visit to
Mines (afternoon).

In the evening Prof. G. H. Darwin will deliver thesecord
portion of the Presidential Address in St. Mary's Hall.

PRETORIA.— .l»n^»s( j7.— Visit to Prcton.i.

In the evening a lecture will be delivered by Mr. A. E.
Shipley, F.R.S., on " Fly-borne Disea,ses, Malaria, &c."

A garden party will be given by His Excellency the
Lieutenant-Governor (Sir Arthur Lawley, K.C.M.G.).
Visits will be paid to the Museum and Zoological Gardens,
and other places of interest. A luncheon will be given by
the Mayor and Town Council of Pretoria. Excursions
can be made to the Dynamite Factory, Modderfontein, and
the Premier Diamond Mine.

The President and most of the members will sleep at
Pretoria, but the Sectional officers return to Johannesburg
in the evening by special train.

JOHANNESBURQ.— ^K^HS/ 31.— In the evening a lecture
will be delivered by Prof. J. O. Arnold on " Steel as an Igneous
Rock."

September 1. — Sectional Meetings (morning) ; General Com-
mittee (afternoon).

In the afternoon there will be a Kafir dance at the Wanderers'
Club. During the Johannesburg visit various excursions will be
made, and visits of inspection paid to Public Huildings and to the
Government Experimental I'arm, Potchefstroom. There will also
be a cross-country trip for a limited number to Mafeking.

BLOEMFONTEIN.— S./'/.w/'cy 2.— A lecture will be de-
livered in the evening by Mr. A. R. Hinks, on " The Milky Way
and the Clouds of Magellan."

A public welcome will be extended to the Association by the
Mayor and Town Council of Bloemfontein, and there will be a
reception at Government House.

Sipttmhir 3 CSunrfay^.— Special train to Mcdderpoort, stopping at
Sannah's Post; lunch on board the train, provided by the hospi-
tality of the town. A trek to Kimberley will be arranged for a
limited number, touching Driefonlein and I'aardeberg, and camping
in General Cronje's old laager.

September </.— I..eave Bloemfontein by special trains for Kim
t)erley.

KlMBERLEy.—.Septemher J.— In the evening a lecture will
be delivered by Sir William Crookes, F.R.S., on " Diamonds."

Underground visits to Mines (in parties) will be made There
will be a garden parly at the Public Gardens.

July, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

171

J by MauU d- Fojr.l

COL. BRUCE, C.B., F.R.S.

Col. Bkuce, R.A.M.C, President of Section I, Physiology, now resident
London, was formerly quartered at Pietermaritzburg. An authority in
nches of Pathological enquiry, he discovered (1887) the micro-organism
of Malta Fever Olicro-coccus Melitemig), In Zululand, under official auspices,
he studied the devastating Tsetse Fly disease, or Nagana. In Uganda, he recently
investigated with striking success the causation of the dreaded malady Sleeping
Sickness, and denoted the actual carrier of the infective organism to be a
species of Tsetse Fly.

MR. H. W. T. WAOER, F.R.S.

Mr. H*eold W. T. Wager, H.M. Inspector of Schools (Secondary
Branch), Prebident of Section K, Botany, was formerly Lecturer on Botany
in Yorkshire College, Leeds. He is the author of numerous botanical
memoirs, among these "The Sexuality of the Fungi"; "On the Phosphoinis
containiog-Elements in Yeast."

SIR R. C. JEBB, M.P., CM.

Sir Richard Claverhouse Jebb, Regius Professor of Greek in the
University of Cambridge, is President of Section L, Educational Science.
A distinguiehed member of the British Academy, he was recently ihe
recipient of the Order of Merit. Ho represents Cambridge Univtrsity in
Parliament.

Scptiiiibcr 6. — In the evening a lecture will be delivered by
Prof. J. Bonsall Porter, of Montreal, on '-The Bearing of
Engineering on Mining."

In the morning the whole body of visitors will entrain at Kimberley
for Beaconsfield. thence to De Beers Sidings, and will proceed by
rail to Du Toil's Pan and Wesselton Mines. Trips will be made to
Kenilworth, Pulsator, and Alexandersfontein.

Seploiihcr 7-S.— Leave Kimberley en route for Bulawayo (Ofticial
party).

BULAWAYO.— .Sc/'^-/;(/)f(' .9.— In the evening a lecture will
be delivered by Mr. Randall Maclver on the " Zimbabwe."

In the CDurse of the mornirg and afternoon the Public Buildings,
Memorials, and Museum will be inspected ; in the evening a conver-
sazione will take place in the Drill Hall.

Scptcmher 10 (Sunday). — Leave for Matopos by train; travel by
coach through the Matopos to the World's View. Inspect Rhodes
Park, the site of the grave of Mr. Cecil Rhodes, Shangani Memorial,
and the Khami Ruins, and return to Bulawayo.

September /?.— Official party leaves for the Victoria Falls.

September ?2.— Arrive at Victoria Falls ; visit the Palm Grove.
Rain Forest, Zambezi Bridge, &c.

September 13. — Leave Victoria Falls (morning) for Bulawayo.

September 14. — Official party arrives at Bulawayo (early morning),
Garden party in South Park (afternoon). Official party leaves for
Cape Town (evening), arriving Sunday, September 17 (afternoon).

September 20. — The Official party, homeward bound, leaves for
England, arriving at Southampton on Saturday, October 7.

Members who are returning to England by the Beira route
leave the Victoria Falls, September 14, and embark on the Durham
Castle on Sunday, September 17. The ports of call are : Mczam-
bique, Zanzibar, Mombasi (Kilindini), Port Said, Marseilles, and
Southampton, the last-named being reached on October 20.

KNOWLEDGE & SCIENTIFIC NEWS.

[JULV, 1905.

THE BRITISH ASSOCIATION, 1905.

President.

PROFESSOR G. H. DARWIN. M.A., LL.D., Ph.D., F.R.S.

.Vice-Presldenls.

HIS EXCELLENCY THE RIGHT HON. THE EARL OF SELBORNE,

G.C.M.G., High Commissioner for Souih Africi.
THE RIGHT HON. LORD MILNER. G.C.B.. G.C.M.G., lale High Ccm-

missioner for South Africa.
THE HON. SIR WALTER F. HELY-HUTCHINSON, G.C.M.G., Governor

of Cape Colony.
COLONEL SIR HENRY E. McCALLUM, G.C.M.G.,R.E., Govemorof Natal.
CAPTAIN THE HON. SIR ARTHfR L.WVLEY, K.C.M.G., Lieulenani-

Govemor, Transvaal.
MAJOR SIR H. J. r.OOLD-ADAMS, K.C.M.G., Lieutenant-Governor, Orange

River Colony.
SIR W. H. MILTON. K.C.M.G., Administrator of Southern Rhodesia.
SIR DAVID GILL, K.C B.. LL.D.. F.R.S. , H.M. Astronomer, Cape Colony.
SIR CHARLES H. T. MtTCALFE. Bart., M.A.
THEODORE REINERT. M.Inst.C.E.
THE .MAYOR OF CAl'E TOWN.
THE MAYOR OF JOHANNESBURG.

THE PRESIDENT. PHILOSOPHICAL SOCIETY OF SOUTH AFRICA.
THE MAYOR OF Dl'RBAN. 'THE .MAYOR OF MARITZBIRG.

THE MAYOR OF BLOEMFONTEIN. ! THE MAYOR OF PRETORIA.
THE MAYOR OF KIMBERLEY. | THE MAYOR OF BULAWAYO.

Qeneral Treasurer.

PROFESSOR JOHN F'ERRY, D.Sc, F.R.S.

Qeneral Secretaries.

MAJOR P. A. MACMAHON, R.A., D.Sc, F.R S.
PROFESSOR W. A. HliRDMAN, D.Sc, F.R.S.

Central Organising Committee for South Africa.

SIR DAVID GILL, K.C. B., F.R.S., Chairman.

]. D. F. GILCHRIST, M.A., Ph.D., B.Sc, Stcrelary.-

A. SILVA WHITE, AssOtanI Secretary.

H. C. STEWARDSON, ChicJ Clerk and Astislant Treoiurer.

Races of

The

SovitK Africa.

1 iiREE m.iin r.ircs ni:iy be distinguished in the south of
the African continent : the Bushmen, the Hottentots,
and the Bantu-speaking peoples. Xone of these
possess any written records, and the only materials for
their history consist in native traditions and folk-lore,
and the reports of travellers of the past hundred years
or so. From these sources of information an attempt
has been made to trace the origins and early relation-
ships of the indigenous tribes, but much work remains
to be done before any definite ethnological grouping can
be verified.

Bushmen. — When the early travellers landed at
the Cape, the first peoples with whom they came in
contact were the .San and Khoikhoi, better known re-
spectively as the Bushmen and the Hottentots. The
former were the aboriginal inhabitants of the south of
the continent, and there is evidence to show that before
the era of the Bantu migrations from the north-east,
they occupied the land south of the equatorial lakes.

The Bushmen were a hunting people, living on the
abundant game, owning no lords, and possessing no
political organisation. But at the very beginnings of
-South African history we see their doom foreshadowed,
for this aboriginal hunting folk could make no stand
against the steady migration of the Bantu-.speaking
tribes pouring down from the north-east, and in the
17th century they were being gradually driven out of
the more fertile lands into the south and west. The
settlers proved an even more d.mgerous enemy on the
south, for by the Kuropeans these aboriginal owners
of the land were treated, not as men, but as wild
animals, to be exterminated. The extermination
would have proceeded more rapidly had not the
Bushmen been possessed of one admirable mc.ins
of defence. Their only weapons were bows and
arrows; the bows usually very poor and the arrows often
merely made of reeds, but the piece of bone, flint, or

iron forming the tip was dipped in deadly poison, which
rendered a slight wound mortal; and the colonists learnt
to mingle fear with their contempt. .Sentries wtjre
practically useless against these wary attackers, and
one Bushman could keep a whole Kuropean settlement
in a state of constant alarm. Owing to his diminutive
size and his extraordinary ability for taking cover, he
could make himself almost invisible, and the skill and
cunning of the born hunter were preternaturally
sharpened when he himself became the quarry. Much
of the disafforesting of .South Africa was due to the fear
of the Bushmen, for the colonists cleared all the bush
near their dwellings to guard against stealthy attacks.

Between the dense masses of Bantu peoples sweep-
ing down from the north-east, and the cver-cncroaching
colonists on the south, the Bushmen were forced to
retreat, and they sought refuge \\\ the fastnesses of the
mountains and in the deserts, where they are still to
be met with, still living in the primitive method, by
hunting, still using the same rude weapons, the bow
and arrow; still in the stone age of culture from which
our ancestors emerged some few thousands of years
ago, and still making fire by friction, like prehistoric
man and savages all over the world.

In physical characteristics they differ considerably
from their Bantu neighbours. The skin colour is
naturally a fawn yellow, and even when obscured by
layers of grease and dirt, it is distinctly lighter than the
prevailing tint in the Dark Continent. 'J'hc black hair
has earned by its method of growth the name of " pep-
per-corns," for though it is distributed normally and
evenly over the surface of the head, the little short black
tufts cling together in tight spirals, leaving bare spaces
between, and suggesting a sprinkling of pepper-corns
over the scalp. The avcr.ige stature is i.^jgni.
(5 ft. o\ in.). The head is low and moderately narrow,
the face straight, without projecting jaws, the nose ex-
tremely low and broad.

Hottentots. — While the Bushmen were nomadic
hunters, the Hottentots were nomadic herdsmen, and
they are generally assumed to represent an early blend
in another part of the continent of Bushmen and Bantu
stocks. In skin colour, in the nature of the hair, in
certain physical characteristics and in speech they show
considerable affinities with the Bushmen, but they are
distinguished by a taller stature, 1.639m. (5 ft. 4! in.),
a narrower head, and pronounced projection of the jaws.

They formerly extended from Namaqualand on the
west to beyond the Limpopo, and traces of their occu-
pation are recognised in the heaps of stones or cairns
which mark the graves of their warriors. The true
Hottentots are now mainly confined to Namaqualand
on the west, but tribal groups of the Korannas
(Koraqua) of the middle and upper Orange ;in(l
\'aal rivers, and I lottcntot-B.intu or IIottcnlot-Bocr
half-breeds, such as the Ciric|uas of ( iriqu.il.ind
K. and the Gonaquas, are relics of lliis once
powerful race. Their extinction is due to many
causes. B.intu inv.isions on the north-east, and
the encroachment of the colonists on the south,
deprived them of the more fertile lands, which
want of organisation prevented them from protecting.
Like the Dinka of the Upper Nile, and the Todas of
the Nilghiris, they have a passionate devotion for their
cattle, and it was on account of their herds that they
first came in conflict with the Dutch settlers, whose
farms threatened their pasturelands. As these were

July, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

173

gradually occupied by the stronger races, the Hotten-
tots could no longer support their herds, their only
means of existence, and many were reduced to slavery
on the farms of the invaders, where their cleverness in
handling cattle made them valuable as drivers of bullock
waggons. Their light attachment to the soil, due
to their inherent love of wandering, made their displace-
ment the less difficult, and the national vice of dacha-
smoking to excess, together with the vice of spirit
drinking, acquired from the settler, accelerated their
degradation.

Koranna. — The Koranna occupied the Middle
Orange in the 17th century, but they were always a rest-
less people, whom nothing would bind to the soil. One
section of them went up the Vaal and formed an inde-
pendent kingdom round the town of Mamusa on the
Harts river, where they still keep up many of the
national customs and speak a corrupt form of the Hot-
tentot language; but owing to their long intercourse
with the Kafir tribes, they have developed the physical
characters of the latter, and cannot be regarded as
pure Hottentots.

Griqiia. — The Griqua are Boer-Hottentot half-
breeds, whose original home was to the north of the
river Olifant. They were forced to retreat before the
colonists and founded a republic at Rietfontein. Dis-
cords soon led to disruption. One section, under Adam
Kok, founded Philippolis and later on Kokstadt in
Griqualand East, and another section, under Andries
Waterboer, founded Griqua Town in Griqualand West.

Bantu. — In Natal we find ourselves in the midst of a
tvpical Bantu people, the Zulu-Xosa, or Zulu-Ivafirs,
from whose language the group-name Bantu (people)
has been chosen as a general term to include all the
African races of Bantu speech. This artificial grouping
conceals a heterogeneous mass, containing at least six
distinct elements, true Negro, Negrillo, Bushman, Hot-
tentot, Hamite, and Semite, which are blended together
in different proportions, producing a wide diversity in
physical type.

The chief characteristics of the main Bantu groups
are a fairly tall stature, a skin colour of varying shades
of red-brown, a high and narrow head, a broad nose,
and thick but not everted lips.

It seems probable that the Bantu type is mainly due
to a blending of the true Negro, of the type found
to-day in greatest purity in West Africa and the Sudan,
with a Hamitic stock, and that the centre of the dis-
persion was somewhere in the neighbourhood of British
East Africa. From their dual ancestry the Bantu in-
herited the aptitude for agriculture, and for cattle-rear-
ing, and, provided thus with an ample suppiv of food,
living in a magnificently fertile area, possessing also a
political organisation, which developed into tribal group-
mg, they flourished, and increased and multiplied to
such an extent that now their teeming millions swarm
over almost the whole of South Africa.

In their earlier wanderings they must have mixed to
a considerable extent with the aboriginal inhabitants,
and we find distinctly Hottentot features among the
Bechuana, who^ are regarded on this and other grounds
as being among the earliest immigrants. The later waves
preserved a purer type, such as the Zulu-Xosa, who are
comparatively recent arrivals in their present territory,
though a long period of contact with the aborigines is
shown by the adoption of three clicks into the language.

Xosa. — At one time the Xosa spread far to the south,

and the first conflict with the whites took place in the
Swellendam district in the middle of the i8th century.
Later on the boundary was fixed at the Gresit Fish
river, but the rapidly increasing people had spread by
1800 as far as Mossel Bay. Then force was brought to
bear on them, and troops were called out, but the general
retreat did not take place until 1835. External restric-
tions produced internal shiftings and d' turbances and
general disorganisation, leading to a loss of indepen-
dence for all the clans.

Zulus. — The history of the Zulus, the northern branch
of the Zulu-Xosa, is well known since the time
when they sprang into notoriety under the famous
Chaka, the terror of whose name was carried for hun-
dreds of miles in every direction by tribes which he had
put to flight. Streams of disorganised people fled
before him, and some of these, encountering weaker
tribes in their flight, attacked them and took possessiori
of their lands : thus the disorganisation spread. Tlie
Fecane, or Fingu, Xezibe, Baca, and Amahlubi fled to
the south, and the Fecane, after being slaves to the con-
querors, were freed in 1835, and formed the Fingu
location near Port Elizabeth.

Matahele. — The Matabele, " the men who dis-
appear," so called from their immense bucklers, having
fled across the Drakensberg, gathered together under
L'msilikatsi and poured in a vast army across Bechuana-
land, conquering the sedentary tribes, and augmenting
their numbers by captives and fugitives. They were
defeated and almost annihilated by the Boers, but this
catastrophe was only a brief check in their victorious
career, which culminated in the defeat of the Mashona
and the occupation of Mashon aland, Rhodesia.

Mashona and J[Iakalaka. — The Mashona and Maka-
laka were probably among the earlier waves of Bantu
migration. Tradition ascribes to the Makalaka a power-
ful kingdom, which lasted for 300 years, between
the Limpopo and the Zambezi, and the Mashona lived
to the north of them as far as the Umfuli river. They
were powerless before the warlike Matabele, and were
either reduced to subjection or sought refuge in flight.

Barotse and Makololo. — Another powerful kingdom
was that of the Barotse, on the middle Zambezi. This
was overthrown by the Makololo, under Sebituane, in
1835, but on the death of Sekeletu, the successor of
Sebituane, the Barotse revolted, drove out the Makololo,
and re-established their empire on a surer footing.

Thus the history of the Bantu peoples is one of con-
tinuous movement, of perpetual shiftings, of states
formed by the grouping of many tribes under one force-
ful leader, and the disruption of these states, either by
natural disintegration when the central power weakens,
or before the attack of some greater or stronger force.
The grouping is political rather than racial, and hence
it tends to produce a blending rather than a differentia-
tion of type.

The ethnology of a country is always influenced by
the environment, and this is notably the case in South
Africa. Here is an immense stretch of country, contain-
ing few barriers to limit expansion in any direction or
to provide security against attack. Hence the racial
history has shown streams of people perpetually moving
in all directions, producing an infinite fusion of types,
a uniformity in diversity, which makes South African
ethnology a subject of unusual complexity, needing a
great deal of patient unravelling before the affinities of
even the main races can be clearly discovered.

174

KNOWLEDGE & SCIENTIFIC NEWS.

[July, 1905.

The DioLmond Mines
of South AfricQc.

About forty-eight jcari ago n child picked up a
diamond in the gravels of the Orange River. Experts in
Europe were not very ready to believe the news, but
others were Qaund, and in 1S70 the gem was discovered
in the so-called " dry ground " — large patches of a
peculiar clayey material well away Irom any stream
course. This was at a spot which is now the noted
Uutoits Pan Mine, near Kimberley. During the next
year three other diamantiferous patches were detected
in this neighbourhood; one, the present Bultfontein
Mine, within a short distance to the south; another,
the Ue Beers, about two miles away to the north-west,
and the third, the Kimberley, about a mile west of it.
They formed low hills or kopjes, rising from a com-
paratively level basin; the tops of the Kimberley and
its neighbour being about 4,000 feet above sea-level,
and the others a few hundred feet lower. The country
rock is a dark shale, with occasional beds of hard
sandstone, belonging to the Karoo series of geologists,
which is either a little older than, or contemporary with,
the European Trias, and is very different from the dia-
mantiferous material, which was afterwards found to
fill large vertical pipes or funnels, descending to an
unknown depth. These were nearly oval in form, the
area of the largest, Dutoits Pan, being about 41 acres;
that of the smallest, the Kimberley, about nine acres.
Since then several other diamantiferous patches have
been discovered, to which we shall presently refer.

The nature of the material and the origin of the gem
have long been geological problems, but the former of
them has at length been solved, and the latter is much
better understood. The difficulty partly arose from the
state of the material. The yellow ground, to use the
miners' name for that first dug up, was a rotten clayey
stuff in which sundry minerals and rock fragments were
scattered. This, they found, passed gradually down —
perhaps a hundred feet from the surface — into a dark
bluish-green material, which they called " blue
ground." Though more coherent than the other, it also
was at first ill-suited for microscopic examination, by
which, however, the minerals scattered through it,
sometimes as fragments, could be determined. The
more notable, besides the diamonds, were garnets of
one or two kinds, iron oxide, generally titaniferous,
a brown mica, named vaalite by Professor Story-
Maskelyne, a chrome-augite, enstatite, and olivine,
more or less converted into serpentine. Fragments of
rock, sedimentary and crystalline, were also present;
the former often seeming slightly altered. About one-
third of the matrix, or blue ground itself, consisted of
very minute fragments of these constituents; about
half was serpentine, and the remainder a carbonate of
lime, sometimes magnesian.

It was impossible to determine the true nature of
this rock, or the origin of the diamond, until the blue
ground was hard enough to be cut into slices sufficiently
thin for a satisfactory examination with the micro-
scope, and this was not reached until the mines were
carried down to some hundreds of feet from the surface.
The exact depth cannot be precisely stated, or that of
the passage from the " yellow " to the " blue ground,"
but it was not till about a dozen years ago that really
good specimens of the latter reached this country. The
Kimberley mines had by that time been carried to a

depth of over a thousand feet, and the material brought
up was about as hard as an ordinary limestone.* These
workings also afforded sections of the rocks pierced
by these great pipes or shafts. First they found the
dark shales already mentioned, sometimes covered,
sometimes cut, by masses of an igneous rock allied to
basalt. These occupy the first few hundred feet. Beneath
them comes a thick mass of simikir rock, an old la\a
flow, often called melaphyre, resting (in the Kimberley
district) on a quartzite or very hard sandstone, which
continues, thickly interbanded with the dark shales, till,
at a depth of more than five hundred yards from the
surface, a floor of very ancient crystalline rock is
reached. The rock fragments in the blue ground are
similar to these, whether sedimentary or igneous; the
shales being sometimes quite unaltered, but sometimes
with a " baked " aspect, especially in their outer
part. The rock, then, is a breccia, and often bears a
rough resemblance to that which fills the volcanic necks
on the Fifeshire coast. That the pipes had been driven
in some way or other through the surrounding rock
was indisputable, but it was for long uncertain whether
the material in them was a true breccia, like that just
mentioned, or some peculiar kind of igneous rock.
The latter view was at first more general, and was not
incompatible with the presence of rock fragments. The
late Professor Carvill Lewis maintained the material
(which he named Kimberlite) to be a peculiar kind of
peridotile — a rock composed mainly of olivine, but with
a glassy matrix — in which the diamonils and other
minerals had formed. But farther examination showed
the latter to be in many cases indubitably broken, and
the rock is now generally admitted to be a true breccia.
It has, however, a volcanic or, perhaps, we should say,
an explosive origin since we find no signs of ordinary
scoria. After the pipes had been filled, steam or hot
water probably continued to be discharged for some
time, converting the ferromagnesian minerals into
serpentine, producing carbonates, forming a peculiar
coating on some of the garnets, and more or less affect-
ing the rock fragments.

This, however, did not settle the question whether
the diamonds had originated in the pipes or elsewhere,
like the other larger minerals. Professor Carvill
Lewis, taking the Kimberlite to be an igneous rock,
held the former view. So did some of those who main-
tained it to be a breccia, for they thought the diamond
had been produced by the action of very hot water on
the carbonaceous material of the dark Karoo shales.
But this hypothesis is beset with insuperable dillicuities.
The crystals of diamond are not unfrequently broken
like the garnets or augites, and w hen ])erfect are often
in a state of strain. Either would be inexplicable had
they been formed in such a material as the breccia.
Besides this, small diamonds have been found at the
De Beers and the Xewlands mine (some forty miles
north-west of Kimberley), more or less included in
garnets, :ind in 1897 they were detected in two boulder-
like pieces of rock which had been brought to England
from the latter mine. One of these, when it was
broken, displayed in the largest fragment no fewer than
ten diamonds, the biggest — an ocl.iliedion — measuring
about three-twentieths of an inch from point to point, t

• See Papers in the Geological Magazine for 1895, p. 492.
Illustrations of the material itself and of its microscopic structure
are given in Carvill Lewis' " The Genesis of the Diamond," 1S97.

t This (ranment was presented l>y the Directors of the Company
to the British Museum. For an account of it, see Proc. Hoy. Soc,
Vol LXV,, p. 223

JULV, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

175

The rock is an eclogite, consisting mainly of red garnets
ranging in size from a hemp seed to a pea, and green
(chromiferous) augite. This eclogite is now regarded
as an igneous rock, and one of those which have
crystallized at a considerable depth from the surface.
Diamonds, with other forms of crystallized carbon,
have been found (though rarely) in meteorites, not only
in those of native iron, as at the Canon Diablo, but in
one composed of this metal crystallized with olivine and
augite, which fell in 1885 at Nova Urei in Russia. Pro-
fessor Moissan has made small diamonds by fusing
carbon in iron, and cooling the mass so as to cause
great pressure at the interior — an experiment which
has been repeated by Sir W. Crookes. We must,
therefore, conclude that the South African diamonds
originated in deep-seated igneous rocks. They have,

View of the Cullinan Diamond, showing one of tli
cleavage plane. Appi

vage pianes.
natural size.

mately
From a Photograph by Sir William Crookes, F.R.S

as yet, been detected only in eclogites, but we may anti-
cipate their occurrence in other crystalline rocks with a
lower percentage of silica, and especially in peridotites.
These deep-seated masses must have been stripped of
their covering and laid bare before the Triassic period
began; fragments were detached and rolled into pebbles,
forming the conglomerate at the base of the Karoo
series, which was duly covered up by the sandstones
and shales towards the end of this period. Move-
ments of the earth's crust in Southern Africa caused
discharges of lava, in the form of flows and dykes.
Then great explosions drilled huge holes through all
these, and hurled the shales, quartzite, conglomerate,
and the shattered crystalline floor into the air. This
mixed stuff, minerals and rock, as it fell back, finally
filled the pipes, which, however, continued to be vents
for gas, steam, and, perhaps, hot water.

Such is the story of the diamond. There are several
other pipes more or less productive, most of which are

scattered on a narrow belt about 125 miles in length,
which runs, roughly, in a N.N.VV. to S.S.E. direction
from Newlands on the Hart river in West
Griqualand to Faure Smith in the Orange State,
parallel, as Dr. Molengraff has pointed out, with
the line of the Drakensberg Range. But the group,
including the l^remier Mine, now famous for the
discovery of the Cullinan diamond, must belong to
quite another zone of disturbance, for it is about seven
leagues east of Pretoria (north of Van der Merve
Station). Here the pipes are driven through quartzite
and an igneous rock called felsite, so the I-iaroo shale
cannot have helped to make these diamonds.

We must pass over the story of the working of the
mines, for it is a long and complicated one, contenting
ourselves with stating that, according to De Launay,

richer mines produce
on an average about
15 grains weight of
diamonds to five
cubic yards of rock,
and that, by 1896,
.South Africa had
produced more than
double the quantity
of Brazil and India
together. A decade
earlier its mines in a
single year yielded
nearly 3 , 160,000
carats of diamonds.

These stones fre-
quently show a very
faint resin-yellow
tint, but many are
perfectly colourless
and free from any
flaw. The first ex-
ceptionally fine one,
the Star of South
Africa, weighing 83^
carats, was found in
i86g. Three years
later diggings on the
Vaal River produced
the Stewart, 228f
carats. The De
Beers Mine came to
the front in 1880
with a diamond
weighing 428^ carats, which was beaten four years
afterwards by one (locality uncertain) weighing
457i carats.—" On June 30, 1893, the Jagers-
fontein Mine (the best in the Orange River State)
broke the world's record by disclosing a diamond
weighing 9715 carats. It was rather irregular in shape
— something Hke a longish potato — measuring about
3 inches by a little less than i| inches." But on
January 25 in the present year that was left far behind
by the Cullinan diamond, which was found about 18
feet below the surface at the Premier Mine, Transvaal,
and of which we give a photograph. It is a stone
of excellent water, weighing about 3,024! carats.*
Yet this monster is itself only a fragment, for four of
its bounding faces are cleavage planes, and experts
think that the stone, when perfect, may have been quite
twice as heavy.

* A carat is 3J grains, Troy.

It is resting on another

KNOWLEDGE & SCIENTIFIC NEWS.

[JLLV, 1905.

SoutK African Natural
History.

An'elopcs. — In spite of what we .sunutimcs hear our
sporting friends chronicle as to their ha\ ing shot this or
that kind of small " deer " in South Africa, meaning,
in reality, some kind of antelope, the fauna of
the country is notable on account of the absence of
representatives of the deer family (Cirvida), as also of
representatives of sheep and goats, and of true wild
cattle. The place of the last named is taken by the
great and ugly Cape buffalo (Bos caffer), an animal
entirclv different, however, from the water-buffalo with
which we are familiar in Italy and other parts of
Southern Europe; and the deer of Europe and Asia
are replaced in South Africa by a vast assemblage of
species of antelopes, many of which are peculiar to the
country, although a large percentage belong to genera
ranging over the greater part of Africa.

One very characteristic animal is the Cape harte-
beest {Dnbalis cama), a melancholy-looking antelope of
the size of a donkey, with a prodigiously long face,
twisted lyrate horns, and a foxy-red coat relieved with
bluish black. Despite its advantage of being one of
the fleetest of South African antelopes, it is now almost
killed off in Cape Colony, the Orange River Colony, and
tlie Trans\aa!, though a few survive in the old Bush-
man country of Cape Colony and in the North-West
Transvaal. In the Kalahari desert big troops still re-
main. The lovely blesbok and boftebok {B. albijrons
and B. fygargus) were also characteristic South
.African antelopes, and at one time occurred in tens of
thousands; but while the former still exists on several
Boer farms in the Orange River Colony and the Trans-
vaal, the latter is represented only by a herd on some
flats forming part of the estate of Mr. Vander-Byl near
.Swellendam, in the south of Cape Colony. Yet another
antelope abundant formerly, w^hen it associated with
quaggas and ostriches, was the white-tailed gnu, or
black wildebeest (ConnochoeUs gnu), which never ranged
north of the Vaal River. Before the Boer war it was
recorded only on a few farms in the Orange River
Colony, and little has been heard since with regard to
the species. North of the Orange River its place is taken
by the brindled gnu, or blue wildebeest (C. taurintis), a
species still locally not uncommon. In connection with
the hartebeest and gnus may be mentioned the bastard
hartebeest, or sassabi (Danialiscus liinutus), which sur-
passes the first in speed, and is an exclusively South
.African species, now relatively scarce.

Of the smaller South African antelopes, the
duiker [Ccphalophus grimmi), the oribi [Oribia scofaria),
the grysbok (Rliaphiceros mclanotis), and the steinbok
(R. campcslris), still survive locally in fair numbers.
The beautiful little klipspringer {Orcotragus sallator),
the so-called South African chamois, is worthy of
notice as a mountain species. In the waterbuck
(Coins elUpsiprymiiuh), easily recf>gniscd by the long and
beautifully-ringed horns of the bucks, and the white
ellipse on the buttocks, we have a magnificent species
now most common in the unhealthy swamps between
the Chobi and Zamliezi. The vaal roebuck (/'eica
capreolus) is a much smaller grey animal, with short
upright horns to the bucks, inhabiting open, hilly
districts south of the Zambezi. Nearly allied is the
fox-red reedbuck (Ccrvicapra arundiiium), a now
scarce species inhabiting river banks. The lovely pala

{JEpyccros nulampiis) and the springbok [Antidorcas
cticJiorc) are inhabitants of the open plains, the latter
formerly found in huge herds which made periodical
migrations (" trek-bokken ") across the country. Herds
of considerable size may still be seen in certain districts.
The splendid sable antelope [Hippotragns niger),
which, with its sabre-like horns and dark coat is, per-
haps, the handsomest of all antelopes, is not
found south of the central Transvaal, and even there is
now scarce. Still rarer is its larger cousin the roan
antelope {H. cqiiinus), though it has wider range.
The southern representative of the group was the
blaaubok (Jl. laicopliccus), of which a few were left in
Soete Melk (its headquarters) in 1781, but the last were
shot about the year 1800.

The northern karoos of Cape Colony were the
favourite haunts of that magnificent South African
antelope, the gemsbok, or oryx {Oryx gascl/a), which
fears not, if report be true, the onset of the lion, but
the species is now very scarce, although a few still
linger on the plains south of the lower course of the
Orange River. Although the elegant little striped
bushbuck (Tragelap/iiis scrip/us) is still fairly common
in many parts of the country, the lordly kudu
(Sirepsiceros capensis) survives in Cape Colony only in
the jungles of the Uitenhage range, where it is pro-
tected by British farmers; while the larger eland
[Taurolragus oryx) has been exterminated from nearly
all the territories likely to be visited by the tnembcrs of
the British Association.

Other Big Came. — Among game animals other
than antelopes, we may refer to giraffes, of
which the Cape form appears to be already
exterminated; the hippopotamus, now becoming
scarce even in many parts of the Zambezi; the
ugly wart-hogs, with their enormous tusks, and their
relatives the bush-pigs, easily recognised by their
tufted ears. In the horse tribe, the true quagga (Egiiiis
qiiagga) of the plains south of the Orange River, and
apparently the typical race of the bonte-quagga or
Burchcll's zebra {Eijiais hiircltcUi), from the north of that
river, have already succumbed to the skin-hunters, but
other races of the latter species occur further north.
The great white rhinoceros, which used to charge the
wagons of the pioneer hunters in mistaken apprehension
of four-footed enemies, survives only in the shape of a
few head specially protected in N.-E. Mashonnland, and
perhaps by others near the junction of the While and
Rlnck Umvlosi Rivers, and would, indeed, have been
practically extinct had it not unexpectedly been dis-
covered on the equator.

Ccncral Mammal Fauna. — Of mammals ollu-r than
big game, and apart from lions and leopards, that are
especially characteristic of the country, the following
may be mentioned : I he spotted hyiena, the aard-wolf
or maned jackaJ, the black-backed jackal, tlie fennec fox,
the hunting dog, and the long-eared fox; various mon-
goose-like creatures, such as the meer-cat; the great
South African baboon; the curious aard-vark or ant-
bear, one of the most extraordinary of all mammals;
and, among smaller forms, the strange golden moles,
so named from the metallic sheen of their fur, and the
great strand-mole from the sand-dunes in the neigh-
bourhood of Cape Town. The Cape klip-dass,
anglicized by the Colonists inio "dassie," is interest-
ing as being the southern representative of an African
group with one out-lying .Svrian member, as to the real
affinities of which naturalists are still somewhat un-
decided.

July, 1905.;

KNOWLEDGE & SCIENTIFIC NEWS.

177

Some South African Birds. — To enumerate even a
tithe of the birds that deserve mention here would be
impossible, but there are a few types, some of which
call for comment.

It is worth travellinsj far to see, for example, such
birds as the penguin and the ostrich in a wild state.
Both flightless types, we have in the one a good illus-
tration of degeneration, and in the other of the substitu-
tion of organs, the wings playing the part of the feet
when swimming.

Though the ostrich is no longer to be found in a wild
state in Cape Colony, it will probably be met with by
those members of the Association who propose to make
their way northwards into Rhodesia. Occasionally
travelling in groups of from thirty to fifty, and then
generally associating with zebras or some of the larger
antelopes, this bird more commonly lives in companies
of not more than four or five, that is to say, the males
appear to live apart, accompanied by their mates.

The actual facts as to the breeding habits of the
ostrich do not seem to have been definitely settled. But
it would appear, according to Professor Newton, that
the females lay their eggs in one nest — a shallow pit
scraped out by the feet, the earth so displaced being
used to form a wall around the eggs. As soon as ten
or twelve eggs have been laid brooding commences.
The cock performs this duty by night, his black plumage
serving as an admirable protective dress at the
time : the females seem to take up this duty in
turns by day. Being soberly clad they harmonise with
the sandy plains under the glare of the sun. About
thirty eggs appear to be laid in the nest, and around it
as many more are scattered, which are commonly
believed to be used as food by the young. Brood-
ing is believed to be resorted to, by day at least,
not so much for the purposes of incubation as to pro-
tect the eggs from prowling jackals. It is open to
question, however, whether this interpretation is cor-
rect, for it is quite possible that by day protection from
the sun is absolutely necessary.

Those privileged to visit an ostrich farm may be likely
enough tO' see an old cock bird " roll." This peculiar
form of display is adopted preparatory to giving battle
to a rival when courting. Suddenly bumping down on
his " knees," he will, says Mr. Cronwright Schreiner,
' ' open his wings . . . and then swing them alter-
nately backwards and forwards . . . as if on a
pivot. . . . The neck is lowered until the head is
on a level with the back, and the head and neck swing
from side to side with the wings, the back of the head
striking with a loud click against the ribs, first on one
side then on the other. The click is produced by the skin
of the neck, which then bulges loosely out just under
the beak and for some distance downwards, and while
" rolling " every feather over the whole body is on end,
and the plumes are open like a large fan. At such a
time the bird sees very imperfectly, if at all."

Tlie chances of meeting with the secretary bird (Ser-
^ctitariiis secrclarius) in Cape Colony are by no means
so certain as before the war. It is one of the most
peculiar of the birds of prey, and one of the most primi-
tive; albeit, in many respects, highly specialised.
It is remarkable for the length of its legs and the
tuft of long feathers resembling quill pens, which
grows out from the sides of the head — hence the
name " secretary bird." It feeds largely on

venomous snakes, and on this account is supposed
to be strictly protected. The prey is killed by means
of blows from the wings, followed by vigorous pound-
mg with the powerful feet. There seems, unfortunately,
to be a tendency to relax the protection hitherto
accorded these birds on the plea that they also eat
animals coming under the head of " game." The
secretary bird builds a huge nest of sticks, placed
on the tops of low bushes. In the interstices of the nests
colonies of sparrows breed, quite unmolested by their
powerful overlords. In Cape Colony the deserted nests
of the secretary birds are now being appropriated by
the Stanley crane. The young remain helpless in the
nest for a period as long as six months, and for a con-
siderable time after leaving this they arc in danger of
snapping their long legs, which appear to be very
brittle, the body, as large as that of an eagle, being
heavy.

Of the other birds of prey we have no space to speak.
Many will see eagles and vultures for the first time
during the visit.

Tlie Hammer-head, a peculiar and aberrant stork of
small size and sombre colour, is one of the curiosities of
Cape Colony. .Among the Dutch element it is known
as the Hammer-kop. This bird, though scarcely larger
than a raven, builds an enormous nest, which may be
as much as six feet in diameter, and placed either in the
fork of a tree or on a rocky ledge. It is made of sticks,
roots, grass and rushes, and it is remarkable for the
fact that it is roofed over and neatly lined with clay,
thereby differing from the nests of all other members of
this order.

Hoopoes and Hornbills, if fortune be kind, may,
perhaps, be met with. Of the former the most likely to
be encountered is a species closely resembling that
which occasionally has the temerity to visit the
British Islands. Tlie Cape species in question is
U. Africana. Flocks of the beautiful Wood-hoopoe
{Rkiuopomastus) flitting from bush to bush, resplendent
in metallic purple but lacking the crest of its more
familiar ally Upupa, may also be looked for. Handsome
and useful as these birds are, they are remarkable for
their evil smell and the foul condition of their nests.
The former appears to be due to a secretion of the oil
gland of both old and young, and in this respect the
Hoopoes appear to be unique among birds. Is is said
that the South American Hoatzin possesses a similar
secretive power.

Hornbills are less likely to be seen, and these will
only be representatives of the curious ground hornbill,
the " Brom-Vogel " of South Africa. This bird is
unique among the hornbills for the great length of its
legs, an adaptation to a more or less terrestrial life. The
Kafirs have a tradition that drought will cease if one of
these birds is sunk under water and drowned.
Nearly all the hornbills are remarkable for the noise
made during flight, which has been likened to that of a
steam engine. The " Brom-Vogel " is said to be
capable of uttering a note resembling a lion's roar, and
audible for a mile.

The hornbills have unique nesting habits, the female
retiring to a hollow tree and being walled in by the
closing up of the entrance to the hole with dung, some
say by the male alone, others say by the efforts of both
birds, their own dung being used for this purpose. In
the Bornean hornbill, at any rate, this plaster is, how-

1 78

KNOWLEDGE & SCIENTIFIC NEWS.

[July, 1905.

ever, not composed of dung;, but of a substance said lo
resemble vegetable resin, and believed to be composed
of a gastric — more probably salivarj- — secretion com-
bined with the woody fragments of fruit. During her
incarceration the female is fed by the male, who, for this
purpose, brings up the contents of his gizzard enclosed
within the inner lining of this organ.

Parrots and Touracoes may be met with, and so also
may the curious Coly or Mouse-bird, and the celebrated
Honey-guide (Indicator), which, like many cuckoos, is
parasitic.

A word as to Cape pigeons and penguins, which will
be the first of the many new birds which will greet the
eye of those who are making their maiden trip to South
Africa. The Cape pigeon is, though so-called, not a
pigeon but a petrel {Daption capcnsis).

The penguin is the species known as the Black-footed
Penguin {Sphcniscus demcrsiis). These representatives of
a really remarkable group are still numerous, and after
the breeding season may be met with in huge flocks
some fifty miles from land. Layard, in his " Birds of
South Africa," describes these birds as having the
" feet placed so far back as to cause the bird to appear
alwavs falling backwards if it attempts to stand on
land." It is not easy to understand how such a state-
ment came to be made, for it is well known that
penguins of all species walk well, if not hurried. The
penguin is an expert diver, using its remarkably trans-
formed wings — which now resemble paddles super-
ficially, hardly distinguishable from the paddles of the
porpoises, for example — when under water, after the
fashion of birds that fly, the feet being held back-
wards as in a bird in flight. The prey is caught and
swallowed under water. Though it is not generally
known, the nostrils of these birds have become
obliterated, as in gannets and cormorants, so that
breathing is possible only through the mouth.

The

Extinct Reptile Favina
of Sovith Africa.

The biological importance of the wonderful series
of remains of extinct South African reptiles which
has been gradually brought to light from the rocks of
the Karoo system of Cape Colony, Griqualand West,
and adjacent territories, hardly needs emphasis. Were
it not for the discovery of this reptilian fauna a gap
would have remained in that chain of animal evolution
which it has been found possible to construct during
the last few years. For, as a matter of fact, these
marvellous Karoo reptiles actually supply the connect-
ing link between the now widely sundered reptilian
and mammalian classes; and without the evidence they
afford it may be affirmed that not even the most in-
genious and far-seeing of evolutionists could ever have
realised how intimate and complete was the connection
between these two groups in past times. Needless to
say, the closeness of the relationship was by no means
fully appreciated at the first outset; and although at an
early stage of the investigation Professor Owen was
enabled to point to a number of very remarkable
mammalian resemblances, both in respect of their bones

and their teeth, it was reserved for his successors to
fully demonstrate that in these strange African reptiles
of a bygone age we have the actual representatives of
the ancestral stock from which mammals originated.
Possibly even this does not fully emphasize the strength
of the case in regard to the interest and importance
attaching to these South African reptiles, for since they
have representatives in other parts of the world, it
might thereby be inferred that these non-African species
would have supplied all the inft)rmation that is really
essential in regard lo the kinship between mammals and
reptiles. As a matter of fact, this is not the case; and
there is a considerable probability that Africa, known
to have existed as a continental area for a prodigiously
long period of time, was really the nursery in which
the mammalian type was first evolved from its reptilian
ancestry, and that some of the African mammal-like
reptiles already known to us are not far removed from
being links between the two groups.

Science is indebted for the first discovery of their
remains to the late Mr. A. G. Bain, an engineer who was
employed in the early part of last century in the con-
struction of military roads on the northern and eastern
frontiers of Cape Colony. The actual first discovery
appears to have been made by him in 1838, in a spot
situated somewhat to the north of Fort Beaufort, near
Mildenhalis. A letter from Mr. Bain, dated Fort
Beaufort, April 28, 1844, addressed to the Geological
Society, records the discovery. Accounts also appeared
from time to time in local journals at the Cape, in some
of which it is mentioned that Mr. Bain's attention was
first attracted by portions of bone projecting from the
rock.

After being cleared from matrix, and thus made
available, the fossils were described by Professor Owen
as a kind of appendix to Mr. Bain's " letter." Mr.
Bain, in the latter, referred to the most remarkable of
his fossils under the name of " bidentals," in allusion
to the single pair of large tusk-like teeth with which
the upper jaw is armed, and it was to a skull of this
type that Professor Owen gave the name of Dicynodon.

In 1S52 Mr. Bain sent another large consignment of
reptilian fossils to our Geological Society, which, on
the advice of the Professor, were subsequently trans-
ferred to the British Museum, together, apparently,
with the first collection.

The interest aroused by Professor Owen's descrip-
tion of these remarkable reptiles, as well as by his refer-
ences to them in lectures delivered before the Royal
College of Surgeons, was very great. Among those
specially interested was the late Prince Consort, who
impressed upon his son, the late Prince Alfred (after-
wards Duke of I'idinburgh), then about to travel in
South Africa, the importance of endeavouring to obtain
additional specimens. This advice was not neglected,
and on his return from South Africa in i860. Prince
Alfred forwarded Professor Owen two skulls, which
were described by the latter in the " Philosophical
Transactions " of the Royal Society for 1862. One of
the skulls, which belonged to a genus nearly allied to
Dicynodon, indicated a new species, and was named
I'lyclwgnalhus alfredi, in honour of the royal collector.

I^revious to this. Sir George Grey, then Governor of
Cape Colony, had also become interested in these dis-
co\eries; and it was lo him that Professor Owen was
indebted for the first example of a representative of
the carnivorous section of these reptiles. Mr. Thomas
Bain, son of and successor to the original collector, was
likewise an energetic worker, and as time went on im-
portant collections of these fossils were brought to-

July, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

179

gether in the museums at Cape Town, Graham's Town,
and Albany. Among other energetic collectors, special
reference must be made to the late Dr. W. G. Ather-
stone, who devoted much time to the advancement of
our knowledge of South African geology and palaeonto-
logy, and to Mr. Alfred Brown, of Aliwal North, the
possessor of a magnificent collection of fossil reptiles,
the result of over forty years' assiduous labour.

Although Professor Owen was the first to describe
and name the remains of these extinct reptiles, several
other workers have followed him in this line of investiga-
tion. A foremost place must be assigned to Professor
H. G. Seeley, F.R.S., who made a journey to South
Africa for the express purpose of collecting specimens
and studying those in the local museums, and who
subsequently published the results of his investigations
in the "Philosophical Transactions." The relations
of these reptiles to mammals formed the leading feature
in Professor Seeley 's investigations. More recently
Dr. R. Broom, now resident In South Africa, has
studied the nature of these fossils.

Soon after the first representatives of the reptilian
remains were obtained it was recognised that the
rocks in which they were entombed formed an ex-
tensive series of freshwater deposits, for which the
distinctive title of Karoo system was selected; the chief
reptile-bearing horizons being those known as the Beau-
fort and the Stomberg beds. It should be added that
in addition to the remains of reptiles, these beds con-
tain ferns of the genus Glossopicris, and that fresh-
water deposits similarly containing Glossopicris, and in
some cases also Dicynodont reptiles, have likewise been
met with in India, Australia, and Argentina. Hence it
has been inferred that in early times the so-called
" Glossopteris flora," with its associated animals,
formed a zone round the world, lying to a great extent
in low latitudes.

The next question was to determine the age of the
Karoo system and its equivalents in other parts of the
world. As the result of much discussion, it is now
generally admitted that this corresponds in the main
with the Trias, or Upper New Red Sandstone of
Europe, although some of the lower beds in the series
may represent the underlying Permian, or the beds
which, in Europe, immediately overlie the Coal-
Measures, and thus form the uppermost division of the
Paleozoic system, as the Trias constitutes the base of
the Mesozoic.

The rocks of the Karoo system consist for the most
part of more or less merely horizontal strata of sand-
stones and shales, ranging from 8,000 to 10,000 feet in
thickness, and extensively traversed by outflows of
igneous rocks. These intrusive sheets consist of the
rock known as dolerite, and form flat table-lands rising
above the general level of the Karoo, giving rise to
the numerous "Tafelbergs" (table-mountains) to be met
with in this part of South Africa.

It now remains to consider briefly the special features
of the South African Karoo reptiles which render them
of such remarkable interest and importance to the evolu-
tionist. In this connection it has to be mentioned that
there is a certain amount of difference of opinion in
regard to the best collective name for these reptiles.
In one of his earlier papers. Professor Owen proposed
the name " Anomodontia " for the Dicynodonts and a
certain British extinct reptile with which they have no
real affinity. In a later work (" Paleontology ") pub-
lished in 1861 this name was, however, taken to include
not only these Dicynodonts, but also the carnivorous

types, although the definition was retained in the
original sense as being applicable only to the
Dicynodonts and associated forms.

According to modern views, these Anomodont reptiles
represent a branch of reptilian stock (the Thero-
niorpha), equal in value to a second branch
(Ornithomorpha), which includes all other reptiles both
living and extinct. This indicates succinctly the real
importance of the Anomodonts, which seem to have
been derived from the earlier Permian salamander-like
creatures known as Labyrinthodonts, and which have
certainly given origin to mammal's. On the other
hand, the second reptilian branch, which gave origin
to birds, seems to have sprung from an entirely
different group of primeval salamanders — the Micro-
saurians. It should be added that it is to the egg-
laying mammals of Australasia (Monotremata), as
represented by the duckbill or platypus, and the echidna
or spiny anteater, that the Anomodont reptiles present
the closest resemblance. These egg-laying mammals
are, however, evidently specialised and aberrant forms,
and it is, consequently, to their extinct and more
generalised ancestors (which we may never discover)
that we must look as constituting the direct links be-
tween reptiles and mammals. Still, as it is, the
connection between the two groups is so close that
some of the Anomodonts have actually been described
as mammals.

To render the resemblances existing between
Anomodonts and the Monotreme mammals apparent to
the general reader, without the aid of illustrati\e dia-
grams, is, of course, a difficult matter. It may be
mentioned, however, that the transition between the
complex lower jaw of an ordinary reptile, articulated to
the skull by means of a quadrate-bone, and the simple
jaw of a mammal, which has no such intermediate con-
nection, is exhibited by the Anomodonts; which also
show how the tripartite knob, or condyle, forming the
articulation of the skull with the vertebral column,
passes into the paired knobs, or condyles, of the
mammal. The bones of the pelvis and shoulder-girdle
(shoulder-blade, coracoid, etc.), are, again, essentially
similar in Anomodonts and Monotremes, and quite
different from those of other reptiles; and a similar re-
semblance is noticeable in the form and perforations of
the humerus or arm-bone, and in regard to the struc-
ture of the wrist and ankle joints. In a word, the
difficulty is, not to discover resemblances, but to point
out differences between the Anomodonts and the Alono-
tremes, although the more typical representatives of the
latter are undoubtedly reptiles in the strictest sense of
that term.

Anomodonts are divisible into the following distinct
groups. First, the Dicynodonts, in which the males
(Dicynodon) are typically provided with a single pair
of tusks in the upper jaw, while the females (Udenodon)
were toothless; other forms having, however, crushing
teeth on the palate; secondly, the Carnivorous, or
Theriodont, type, like Galesatinis, in which the whole
skull and dentition is marvellously manmial-like;
thirdly, the Cotylosauria, in which the hinder part of
the skull was partly roofed over; and, fourthly, the
Pariasauria, in which the whole skull was roofed and
its bones sculptured, so that the resemblance to a
labyrinthodont salamander becomes exceedingly close.
Some of these creatures, notably Pariasaurus, certain
species of Dicynodon, and a few Theriodonts, were of
enormous bodily size — as large as crocodiles.

i8d

KNOWLEDGE & SCIENTIFIC NEWS.

[July, 1905.

The ZaLiTibezi OLiid its
Sights.

\o longer can it be said that the \'ictoria Falls are
inaccessible, for now luxurious corridor trains are run-
ning made up of sleeping,
dining and buffet cars,
fitted up with library,
writing room, bath rooms,
observation platforms, and
other accessories, perform-
ing the journey from Cape
Town in three-and-a-half
days, or from Beira in two-
and-a-half days.

At a point some two
miles before the end of the
journey is reached, a fine
view is obtained of the
broad level valley of the
Zambezi river, with the
deep and precipitous (irand
Canon, zig-zagging like
the path of a lightning
flash for over forty miles
through the hard basalt;
while beyond is seen a
f;limpse of the calm broad
river gliding peacefully to-
wards the great chasm,
whose presence, though
hidden by the dark green
foliage of the adjacent

Rain forest, is clearly marked by a wall of whirling
spray.

Long before reaching the falls columns of spray can
be seen rising like clouds far into the air, and when, at
intermediate stations, the train comes to a standstill
the car rccci\es a dull distant roar of sound.

\ /■ Z AT Im B E rvZ

the (jrund Canon.
Hill stay is just \lsihlc under llu- cross.

A glance at the accompanying plan (I'ig. i) is
necessary to enable the geography of the river to be
clearly understood. The milc-widc expanse of cahn
water, broken by numerous islands, is terminated
suddenly by a long, narrow chasm stretching at right
angles across the river; in wild, tumultuous foam of
dazzling whiteness, this mass of water is hurled down
some 260 to 380 feet with the roar of thunder into the
dark depths, the very earth trembling from the
incessant blows. The air drawn down by this
irresistible volume of falling water, catches up the
broken spray and whirls it in drenching gusts far
above to form the cloud-like columns, which ha\e been
computed (by theodolite) during the rainy season as
rising to a height of three thousand feet. From out
the chasm there is no exit, except at a point about two-
thirds of the distance across the river, where the
opposite wall of basalt has been broken through in a
narrow gorge, (lathered at this spot and contracted
to less than 100 feet in width, the river here enters the
Boiling I'ot, so called, not because of its turbulence,
but, on the contrary, from its placid swirling surface,
that is broken only by counlless air bubbles which rise
from the depths of the main current. At the lower end
or lip of the Boiling I'ot the waters emerge in the
form of a huge mill-race, which dashes itself against
the precipitous wall of the canon, h.ilf going to form
the whirlpf)ol at the foot of I'alni Kl()f)f, while the re-
mainder, flowing at right angles to its former direction,
rages between these stupendous cliffs for over forty
miles.

When the river is low, small craft, if carefully
handled, can approach to within a hundred yards of the
lip of the falls at poins where the current is not swift.

July, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

It was in this way that Livingstone, who first visited
tiie scone, came down stream in a " dug-out," hmding-
on the island, which bears his name (see Fig-, i), and
which is perched on the very brink of the chasm and
almost in the middle of the falls. The views obtained
from this point are by far the finest and most impres-
sive, and for tliis reason it is well worth the while of
visitors to refrain for the first day from stopping at the
well-placed hotel on he south bank of the river, and to
continue the journey until the new township of Living-
stone on the north bank is reached; by doing- this a
glimpse only is caught of the canon and falls while
crossing the bridge, but it is a foretaste of what
is to come. Then, chartering a boat on arrival,
the quiet beauties of the
upper river may be en-
joyed while gliding down
stream until Livingstone
Island is reached. The
remembrance of the first
view from this vantage
point will ever remain in
the mind's eye.

Visitors are ac-
customed to stop on
the south bank, where a
comfortable and well-
managed hotel has been
erected by the Rhodesia
Railways. From here it
is but half a mile to the
west end of the chasm,
and all the wonders of
this masterpiece of
nature can be readily
approached.

The Zambezi above
the falls, save for a few
rocky bars causing small
rapids, is a beautiful
wide river, flowing for
many miles and dotted
with numerous islands,
which are thickly
covered with tropical
vegetation, forming a
habitation not only for
an infinite variety of
waterfowl, but also for
the treacherous croco-
dile and the bellowing
hippopotamus. Game,
too, is plentiful along its
banks, and the tiger fish
affords as good sport as
the salmon. A particu-
larly fine open reach
about a mile above the
falls has lately been the
scene of a first regatta.

The bridge (Fig. 2)
now completed, carry-
ing the projected Cape to
Cairo Railway, spans the
Grand Canon at a point
just below the whirlpool,
and is placed so as not
to interfere with views
of the falls. Far from

being an eye-sore, the structure is of light and graceful
design, eminently fitted for its purpose and to the
locality; moreover, it seems to enable one to realise all
the better the great depth of the gorge and the enor-
mous scale on which Nature has wrought her work.

It consists of one main parabolic arch of 500 feet
spaa, resting on blocks of concrete set in the sheer cliff,
and, with two subsidiary end spans, the total length is
brought up to 650 feet. The whole is supported on four
steel bearing pins six feet long and 12 inches in diame-
ter, and each pin takes a load of 1,640 tons.

.Scaffolding being, of course, impossible, the bridge
was made to support itself, as the two halves were
built outwards. This was effected by attaching cables

Plinto by PeilroUi, Siilairaiiu.

Pig- 3.— The Victoria Falls

The Main Fall at low water, as seen from Livingstone island.

l82

KNOWLEDGE & SCIENTIFIC NEWS.

fjULY, 1905.

to the steel work and anchoring' them back in the solid
rock behind, and as the electric cranes standing- on the
completed portion built the bridge forwards, extra
cables were affixed until, on April ist last, the two
halves met.

The process by which the Zambezi has cut its erratic
course has been traced by Mr. A. J. C. Molyneux in the
Geographical Journal * The basalt rock, when cooling,
developed cracks and fissures, due to contraction, and
i'.ssumed the columnar form. The cutting back of the
falls is concluded to be due to the water falling down
upon and into these cracks; with the constant vibration
the columns are rent asunder and fall in huge flakes into
the chasm. Little evidence is seen of the rock being
worn away by attrition, the blocks newly fallen into the
chasm still retaining their sharp angles. Tliesc block.s
gradually disappear into the Grand Canon impelled by
the rush of the current, and are constantly grinding
down and deepening the bed, to emerge as rounded
pebbles at the eastern end.

The zigzags are held to be due partly to the position
of the islands that studded the river (as now), and to the
existence of master joints and fissures in the basalt.
Where an island occurs there the erosive action of the
water has no effect, hence the extraordinary isolated
bluffs and knife edges of rock connecting them. There
are no signs that the earth was cracked in this form by
some seismic convulsion, or that a material softer than
the surrounding basalt has been eaten away by the
action of the water.

One of the chief glories of the falls is the wealth of
colour, not only in the rich foliage of the tropical vege-
tation, or the dazzling white masses of tumbling foam,
but in the prismatic Ix>ws sparkling in the mist. When
walking between the forest and the chasm, a small bow
may be seen almost within touch of the hand, and
faithfully following; then there is the more ordinary
type spanning the gorge or irradiating the gloomy
depths below, and rendered especially beautiful by the
soft rays of the moon.

Many members of the British Association who are
visiting- South Africa intend to travel as far
north as the Zambezi. TTic climate at that season
of the year will be found dry and warm, while mos-
quitoes and fever are happily absent. The volume of
water, too, has been diminishing since May, conse-
quently the curtain of spray will be in great measure
drawn aside, disclosing the beauties of the falling
water and the depths of the chasm.

• Vol. XXV., No. I, 1905.

South Africa.n Association for the
Advancement of Science.

From a suggestion to arrange for an Annual Congress of
Engineers in South Africa arose the larger idea of a federated
body in science on the model of the home British Association.
The first practical step was taken in March, 1901, at a meet-
ing held in Cape Town, Sir Charles Metcalfe presiding. The
main impetus to the movement for such an organisation was
given by Mr.T. Reunert, M.Inst.C.K., a resident of Johannes-
burg, and he, indeed, may be regarded as the father and
founder of the South African Association. The first meeting
was held at Cape Town in 1903, under the Presidency of
Sir David Gill, with a membership of 700, since increased to
over 2000 ; the second at Johannesburg, Sir C. Metcalfe,
presiding. No meeting is to be held in the present year.

The Royal Observatory
©lI the Ca^pe.

The first oflicial document relating to the Royal Ob-
servatory at the Cape of Good Hope is a minute of
proceedings of a meeting of " Commissioners appointed
ijy .\ct of Parliament for more effectually discovering
the longitude at sea," it is dated February 3, i8:;o.
The establishment of an observatory was proposed at
this meeting by Mr. Davies Gilbert, M.P., and seconded
by Sir Joseph Banks, P. R.S. By an Order in Council
nuthority was given on October 20, 1S20, for the estab-
lishment of a staff, consisting of an astrononier and

rttoto hy Maun d Foi.J

SIR DAVID QILL, K.C.B., F.R.S.,
H.M. Astronomer at the Cape ol Good Hope.

assistant astronomer. The equipment was a 25-feet
zenith micrometer by Troughton, a transit by Dollond,
a 6-foot mural circle by Jones, and an equatorial sector
and a 6-fect .Vewtonian reflector were provided from
(jreenwich. Although the primary oljjcct in founding
the observatory was to provide ships sailing to India
and the East with accurate time, it was recognised that
a suitable opportunity had presented itself for founding
a great national observatory in the Southern Hemi-
sphere. The first astionomer was the Rev. Fcaron
Fallows, F.R..S., who arrived at the Cape in 1821,
bringing with him some portable instruments. His
first instructions were to find a suitable site. The pre-
sent one, it should be said, was chosen after trying
several others, which had to be abandoned on account
of drifting sand or of cloud, and many were the annoy-
ances and discomforts encountered during these pre-
liminary efforts. For over three years I'allows lived
in a hut superintending the building f)f the observatory.
At last, in 1829, he found it possible to begin regul:ir
astronomical work, but he could not accomplish much

July, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

183

through want of proper assistance. Before his death,
in 1831, he had observed over 3,000 transits, and had
made several hundred circle observations, which were
subsequently reduced by Airy. Thomas Henderson,
who succeeded Fallows, remained at the Cape for 14
months, but in that short time he had made a large
number of first-rate observations, the most important
I)eing meridian places of o Centauri, from which he
found a parallax of about i''.

Highly valuable observations were made by the next
astronomer, Sir Thomas Maclear (1834 to 1870), but
owing to inadequate assistance the reduction of a large
part of them had to be left to his successors. Mr.
E. |. Stone, F.R.S., who succeeded him, received, how-
ever, instructions to reduce them as quickly as possi-
ble, and from these observations three star catalogues
have been formed.

In 1879, when Mr. (now Sir) David Gill took up his
duties, there were only three assistants on the staff and
three or four computers, the latter on the same footing
as at Greenwich; now the scientific staff numbers 12,
with 10 to 15 male and female computers. The instru-
mental equipment, too, has been greatly increased. In
1880 it consisted chiefly of the transit circle and a 7-inch
equatorial, but the additions since that date include
the Victoria telescope, the gift of the late Mr. F.
McClean, F.R.S., a new and specially designed transit
circle, an elaborate astronomical clock recently
installed, an astrographic telescope, employed chiefly
on the international " Carte du Ciel," a 7-inch helio-
meter, and numerous smaller instruments.

Of the work already completed by Sir David Gill,
perhaps the most important is the determination of the
solar parallax from observations of the minor planets
Victoria, Sappho, and Iris. Over 20 observatories con-
tributed towards this work, and at the Cape, where
nearly all the reductions were made, more than 16,000
observations were made with the heliometer. The re-
sult is a solar parallax of nearly 8"'8o, corresponding
to a distance of the earth from the sun of 92,874,000
miles, a value generally adopted in national Epheme-
rides. We may refer also to the compilation of three
large star catalogues, the reduction of Maclear's
observations, the determination of stellar parallax with
the heliometer, the work done with the astrographic
equatorial for the " Carte du Ciel " and for the " Cape
Photographic Durchmusterung. " The latter is a cata-
logue containing the places, reliable to iH, and magni-
tudes of 454,875 stars from declination — 19° to the
south pole. Some 2,500 plates were taken for this,
and the arduous work of measuring them and making
the catalogue was undertaken by Prof. Kapteyn.
During the course of measurement a great number of
interesting variable stars were detected, also a star
with the greatest known proper motion. The measure-
ment of the plates, which is still going on, is entrusted
to ladies. So far about 800 plates have been measured,
containing nearly half a million stars.

Another piece of work under Sir David Gill's super-
vision is the partly-completed geodetic survey of South
Africa.

The Victoria telescope and accessories, with the
dome and attached laboratories, was the gift of Mr.
McClean, and is devoted to the study of astrophysics.
The dome is provided with a rising floor which is
worked by hydraulic machinery. The telescope itself
consists essentially of two parallel tubes tied together,
one for a 24-inch photographic lens, the other for an
18-inch visual: and there can be attached to it two

large objective prisms or a large slit spectroscope for
determinations of velocity in the line of sight. Many
interesting spectra have already been photographed
and measured.

The new transit circle has been specially designed to
be free from the effects of temperature change, and is
being used to make the most refined fundamental ob-
servations. It can be readily reversed in its trunnions,
can have the object-glass end and the eye end inter-
changed, and is fitted with Repsold's micrometer with
moving wire for observing transits. To bring this
installation into proper working order and to deter-
mine all such instrumental constants as division errors
of the circles, periodic errors of screws, and other
details, necessarily consumes time and demands much
patience, but in his last report. His Majesty's
astronomer stated that " the new transit circle will be
brought into regular catalogue observing work from
the beginning of 1905." The old transit circle is still
in use for the time service, an important part of the
observatory's work. The instant of Greenwich noon
is signalled every day to Simon's Town, Cape Town,
Port Elizabeth, and East London, and all the railway
clocks on the Wynberg line are automatically set every
hour, a system which is being extended to other
portions of the Government railways.

To provide fixed meridian marks for azimuth refer-
ence, deep pits have been sunk, and on the bed rock
at the bottom of them the marks rest. A clock for
use in connection with the new transit circle has also
been installed, the pendulum of which swings in an
air-tight case, in which the air is automatically kept
at a imiform pressure and temperature.

The Sovith AfricsLii
Museum, Ce^pe Town..

The only institution connected with zoology in South
Africa which is provided with a scientific staff and is
doing original work, apart from the mere acquisition
and arrangement of specimens, is the South African
Museum at Cape Town. This museum was founded by
the late Sir George Grey when Governor of the Colony
in 1855, and its first Curator was Edgar Leopold Layard
(a brother of Layard of Nineveh fame), who was well-
known as an enthusiastic naturalist. Layard was the
author of many books and papers on zoology, and like-
wise an excellent field-naturalist. His best known book
is his "Birds of .South Africa," of which the first
edition was published in 1867. The second edition, in
preparing which Layard was assisted by Dr. Bowdler
Sharpe, was completed in 1884, and has until quite
lately been the recognised book of reference on South
African ornithology.

In 1872 Layard left the Cape to take up a consular
appointment in New Caledonia, and was suc-
ceeded by Mr. Roland Trimen, F.R.S., distin-
guished as an entomologist, and especially for his
knowledge of the Lepidoptera. Mr. Trimen held the
appointment for 23 years. His excellent work on the
butterflies of Cape Colony and surrounding districts

1 84

KNOWLEDGE & SCIENTIFIC NEWS.

[July, 1905.

(" Rhopalocera Africae Australis ") will always render
his name well known in the annals of African zoology.

In 1895 Mr. Trimen resigned his appointment for
reasons of health, and in December of that year Mr.
William Lutley Sclatcr, at that time a science
master at Eton Colleg'e, was selected by the trustees to
succeed him, and was appointed Director of the
Museum.

Mr. Sclater arrived at Cape Town in March, 1896,
just in time to preside at the removal of the collections
from the old quarters in which they had been previously
kept, to the new and commodious building which
had been completed in 1895, and which is situated in
the public garden in the best part of Cape Town near
the Cathedral and House of Parliament. The building
is of two storeys, the ground floor being devoted to the
geological and mineralogical collections and the inver-
tebrata, and the upper floor to the exhibition of the
mammals, birds, reptiles, and fishes of South Africa,
of which there is a very good illustrative series, though
many hicunce remain to be filled up. Mr. Sclatcr,
I)esides his general duties as Director, has charge of the
collection of vertebrates. As regards the invertebrates,
he is ably assisted by Mr. L. .\. Peringucy, the Assistant
Director, who is a well-known authority on Coleoptera
and other insects. Tlie first assistant. Dr. W. !•".
Purcell, who is also well known for his original re-
searches on the scorpions and spiders of South Africa,
has charge of a portion of the invertebrata. \ fourth
member of the zoological staff is Dr. J. D. F. Gilchrist,
who is honorary keeper of the marine invertebrates,
but whose main duties are to develop the fisheries of the
Cape seas, which are under the charge of the -Agricul-
tural Department of the Colonial Government.

The keeper of the important department of geology
and mineralogy at the South African Museum is Dr.
G. S. Corstorphine, who is associated with Mr. E. H.
L. Schwarz, of the Geological Survey of the Colony,
and they have the care of the fossils and other speci-
mens collected by the Survey.

Two good pieces of work have been started by the
present Director since his appointment. These are a
.series of manuals on the fauna of .Africa south of the
Zambezi, and a periodical called " Annals of the South
African ^[useum." Of the first of these the two
volumes on the mammals were prepared by Mr. .Sclater
in 1900 and 1901.

The " Birds of South .Africa " was entrusted to the
late Dr. Stark, a well-known authority on the subject,
and the first volume was published in 1900. But .Stark,
who volunteered for the medical service of the linglish
Army, unfortunately lost his life in the siege of Lady-
smith, and the second and third volumes on the birds
have been written by Mr. Sclater, with some assistance
from .St.ark's field notes. 'Hie fourth volume concluding
this work is now in the press.

The " .Annals of the .South -African Museum " contain
scientific memoirs, prepared mostly by the members of
the official staff of the Museum or other naturalists
working with them. Two vfilumes and twelve parts
have already been issued.

Naturalists will sec, therefore, that much good work
has been done in the South .African Museum, and that
more is likely to come from it. We should also be
grateful to the three Trustees nf the Museum, Mr.
Merriman, Sir David Gill, and Dr. T. Muir, .Superin-
tendent-General of Education, three well-known per-
sonages in Cape Town, who have assisted in every way
the efforts to increase the usefulness of the institution.

Sta^r Mslp No. 12.

The So\itK Pola.r Region.

This map, though not issued in its proper order of sequence
(Nos. 1, 2, and 3 having appeared in the last three issues of
" Knowledge "), may be useful to those visiting the Southern
hemisphere.

The Southern Cross (Crux) is alw.iys considered as the
ruling constellation of austral skies. It is situ-ited in the
Milky Way, just to one side of the " Coal Sack," a space quite
devoid of stars. Another group of stars of very similar
arrangement (e and 1 Carina;, with 5 and k Vahe) are often
mistaken for it, and is consequently known as " The False
Cross."

Two peculiar objects are the Great and Little Magellanic
Clouds, looking like detached portions of the Milky Way.
Examined with a powerful telescope, these are found to con-
sist of masses of star clusters and detached nebuhe, and would
seem likely to be altogether separate " universes " at a vast
distance off.

Around the actual South Pole is a noticeable absence of
conspicuous stars, and though this feature alone enables one to
judge of the general position, it is more difficult to recognise
the true South from the stars than it is to find true North when
Polaris is visible. Vet beyond 20 to 30 degrees from the Pole
occurs a number of bright and easily recognised stars. The
upright shaft of the Southern Cross points nearly North and
South, and the line l>cing continued through the South Pole,
runs into the Little Magellanic Cloud. To be more exact,
however, one should continue this line further, and thus find
Achernar (a Eridani). A line joining this with /i Centauri (the
nearer of the so-called "pointers" to the Southern Cross) runs
directly through the .South Pole, which is just about midway
between the two. Among the more specially interesting
objects in this region are : —

Cluster 47 Toucani (oh. 20m. — 72° 30'). A fine star cluster
visible to the naked eye as a hazy star. Over 2000 stars, in-
cluding 6 variables, are included in it.

o Criicis (Acnix) XILh. 2:m. — 62° a') is a triple star.
Magnitudes, i'3, i'8, and 6.

K Cnicis (XH. h. 43m. — 59° 30') is a cluster of over 100
stars. They are of many different colours, and present a
beautifiil sight in a good telescope,

a Ccittiiuri (Ki<iil ill Keiilaunis) (XI\'.h. 23m. — 60' 26') is well
known as being the nearest star. Vet its distance is not easy
to realise. It is computed to be about two htmdred thou.snnd
times the mean distance of the Sun from the earth. The light
takes over 3.I years to come to us. This star has a parallax of
o"75. It is a binary, the two stars being at a distance of 2 i"'(j,
and of nearly equal size.

aArgus(Ciinofiiis) (Vl.h. 21m — 52° 3S')is the second brightest
star in the heavens, being classified at - I'o magnitude.

1) Carina or Ar/^iis ( X.h. 41m. — 59" 10') is a most peculiar
variable. Two hundred years .ago it was of the 4th m.agnitude.
In 1837 it increased in brightness till it became a ist magni-
tude. It then diminished a little, but six years later had a
brilliancy comparable to that of Sirius, after which it gradu-
ally dwindled away to the 7th magnitude. It is surrounded
by a remarkable nebula, known as the " Keyhole "on account
of the well-defined dark opening in its centre.

Ouite recently careful photographic surveys have been made
of the Small Magellanic Cloud at the Arequipa Observatory.
These prove the existence of a very large number of variable
stars, there being within this region a proportion of one vari-
able to every 30H stars, which is nearly ten times the ordin.iry
proportion. One star of the 13th magnitud<' was fo'uid to
have a proper motion amounting to -j- o'i3 s. in K.A., and
-|- o"'42 in Dec.

Supplement to "Knowledge A acientiflo News,"
8PE0IAL NUMBEK. JiUy 16th. 1905.
(British Association Meeting.)

MAP No. 12.

MAP 7

MAP No. 12.
The South Polar Regiorv.

iiiiiimiifini«in»iiiinftiiiii>iPtiiiii«wiii>iniiwwiM>i"''—™j"

July, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

185

Photography AbrooLd.

Ca.mera. Work for Travellers.

Doubtless a larg-e number of the members of the
British Association who will g-o to South Africa, pur-
pose taking- cameras with them in order to bring home
records of their visit. Many of them will be experienced
photographers who know exactly what they want and
how to gfet it, but there will certainly be others who
have done little if any work of this kind before, and
some may hesitate as to whether it is worth while to
run the risk of failure, seeing the expense and trouble
that would be incurred. Accordingly it is to the inex-
perienced that these notes are addressed.

The uncertainty and difficulty that used to beset
photography abroad have almost disappeared. The
experience by which we are now able to profit,
and the efforts of manufacturers to make every-
thing easy, have reduced the practice of photography,
such as is here referred to, to the simplest of opera-
tions wherever it may be carried on. No one, therefore,
need hesitate to take a camera for fear their trouble will
be wasted.

But it is necessary to note that apparatus and
methods that would well serve, and, indeed, best serve,
if photography were the primary object of the visit,
would not only be out of place and a constant source of
annoyance, but quite impracticable under the existing
circumstances.

Appciraliis, its Weight and Bulk. — We have often been
told by persons about to travel, that weight is scarcely
worth consideration, and that bulk, too, is a minor
matter, because the luggage is carried by servants;
but that rough usage must be guarded against, for
packages are sure to be knocked about. In the present
case, however, these circumstances will be reversed.
Each will carry his own camera and be able to take
reasonable care of it; therefore, weight and bulk be-
come very important items. This at once excludes
all box cameras and non-folding apparatus; except, in-
deed, for the enthusiast regardless whether his photo-
graphy prove a burden to himself, and perhaps also a
nuisance to other people. There are many very small
cameras that may be exceptions to this generalisation,
but we have in view the production of photographs not
smaller than about quarter-plate size, 4J x 3J inches.

In judging of weight and bulk, it is important to con-
sider two distinct things, namely, the apparatus that
has to be carried about when in use, and also the
apparatus and material that will be left at the hotel,
such as the stock of sensitive material, developers, and
so on. Concerning the latter, little need be said, but
purchasers are often deceived as to the portability of
the camera and what must be taken with it whenever
it is to be used. There is no gain in having a com-
pact and light camera if it has to be carried in a large
and heavy case. Tlie apparatus must be judged of
\\hen in exactly the condition in which it will come into
play, with everything ready for making a series of ex-
posures. If any part is loose, such as a changing box,
backs, or other contrivances for carrying the plates of

films, this part must be included. If glass plates are
to be used, a full stock, six, or a dozen, of the.se should
be added, for their weight is far from negligible.

The Camera. — Having regard to the circumstances
enumerated, the apparatus that may be considered the
most suitable is an entirely self-contained camera of the
folding kind, arranged to take spools of rolled films.
A folding pocket Kodak for quarter-plate pictures
that we ourselves use is but little over an inch
and a half in thickness, and a very substantial leather
case provided for it is under two inches in thickness.
Such a package is no burden, and is absolutely self-
contained. Tliere are other similar cameras to be
obtained, and if the thickness may be increased a little,
folding cameras of greater scope and of more general
applicability, though probably not more useful on such
a visit as this, are available.

The Lens. — By paying three or four pounds more, a
first-class lens may be substituted for the ordinary one.
This, of course, would be an advantage, but in the
present instance so small a one that we do not recom-
mend it, except for those who' know that the work they
mean tO' do will be benefited by it. The gain in using a
costly lens is a better definition at the margins of the
picture, with the possibility, therefore, of using a larger
diaphragm and consequently giving a shorter exposure.
But under the ordinary conditions that may be expected,
the diaphragm of the cheaper lens may be small enough
to secure good definition at the same time that the
exposure is as short as is likely to be desirable.

Other Apparatus. — As to a tripod, if one be taken it
should be a light one. Some metal stands are perfect
in every way, compact and light, but the sliding parts
of the legs if bruised are likely to become fixed or
irreparably damaged, therefore a wooden one is prefer-
able. But if a tripod is taken it will probably not be
used, for experience shows that on such occasions .1
stand is so seldom wanted that it is not habitually
carried with the camera, and that when the need for it
does arise, it is not at hand. It may also be noted that
It takes much longer tO' mount a camera on a tripod
than to use it in the hand, and that when accompanying
a party there is often no opportunity to take things
leisurely.

It is a distinct advantage to have an " everset "
shutter, because the "setting" of the shutter that is
otherwise necessary is the one operation most likely to
be forgotten. The only apparatus that it is desirable
to carry besides what the word " camera " in its inclu-
sive sense signifies, is an exposure meter or actinomeler
for use as described below. There are several kinds of
these, some as small as a locket, the essential feature
being that they contain sensitive paper that darkens on
exposure, and gives an indication of the intensity of the
light by noticing the time necessary to expose it for the
production of a colour equal in depth to a standard
tint.

Development. — In hot countries and trying climates
it is not safe to keep exposed films long between ex-
posure and development. It is possible to send them or
bring them home for treatment at leisure, but it must be
remembered that sensitive material is much more liable
to injury from adverse climatic influences after than
before exposure, and that any delay incurs risk and is
practically certain to cause deterioration. The best
method is to develop as soon after exposure as possible,
that is, within a dav or two, and here it is that the

i86

KNOWLEDGE & SCIENTIFIC NEWS.

[July, 1905.

use of rollable films presents an advantag'e that can
scarcely be overrated. By means of a "developing:
machine " a whole roll of a dozen exposures can be
developed at once, without any need for a dark
room or its equivalent, and with a ven,- much greater
certainty of a jrood proportion of successful neg-atives
than can be claimed for any other method. As a recent
experience of what may be expected from such a manner
of work, it may be mentioned that a friend of the writer,
who does not claim to be even an amateur photographer,
made a few months ago about three hundred and fifty
exposures in and near the Soudan, and of these he has
lost only ten or a dozen, which were spoilt by faults
in using the camera, such as forgetting to wind up a
new film after expo.«:ure. All the rest are useful, and a
very large proportion technically perfect, without stains
or faults. In using the machine — which is only a tank
to hold the developer, and an arrangement for wind-
ing the length of film into a convenient roll for treat-
ment— the best way is to take the developing powders
that the makers provide in suitable small packets, and
to follow the instructions as to lime, &c., that are given
with the apparatus.

Packing, <tc. — The packing of the stock of sensitive
films may well be left to the makers, for their consider-
able experience in sending such material abroad may be
relied on; but it should be seen that they clearly under-
stand where the material is to be taken to. It is usual
to put each spool of film into a tin box, and if the lid
is made secure by means of adhesive plaster instead of
being soldered down, the tins can be used more than
once — or for re-packing.

Rehearsal and General Procedure. — Before starting, a
few exposures should be made and developed by way of
rehearsal. A spool of six films, and, if necessary, a
second similar one, will serve well for this purpose.
With the shutter .set at the twenty-fifth of a second,
and the lens diaphragm at f/ii, f/i6, and f/22 respec-
tively for each of three exposures on a suitable subject
in good light, a sufficient idea will he obtained as to the
conditions necessary. The exposure meter should be
used at the same time, noting the number of seconds
required to produce the standard tint. To adjust a sub-
sequent exposure to an alteration in the value of the
light, as shown by the different time necessary to pro-
duce the standard tint in the exposure meter, it is better
to vary the lens aperture, for this change can be relied
on, each aperture giving double the exposure of the
next smaller. The shutter speeds arc generally not
exactly as marked, and it is possible that by pushing
the pointer to the figure that indicates half the exposure
just given, there may be no alteration in the duration
of the exposure. \\'ith constant fine weather, it may not
be necessary to test the light perhaps for days together,
but if the weather changes, or the subject is unduly
shaded, as it may be in towns or under trees, then the
exposure meter should be used. If a longer exposure
becomes necessary than the one suggested, the camera
should be supported on or against some steady object,
such as a wall, a gate, or a tree. Then, unless the times
of the other settings' of the shutter have been experi-
mentally determined, it will be best to set the shutter
index to " B" or '' bulb," when the shutter will remain
open as long as the bulb is pressed, and will shut as
soon as it is released. Exposures of a quarter of a
second and upward can be easily given in this way after
a little practice.

The Greact Zimbab^ve,
RhodesidL.

Amo.vg the scientific matters which will be considered
by the British Association in the course of its visit to
South Africa is the question of the origin of the ancient
ruins which are scattered so profusely over the whole
of Southern Rhodesia — an area extending some six
hundred miles from east to west, and five hundred
miles from north to south.

This territory, situated far inland from the shores of
the Indian Ocean, appears to have some connection
with the ancient history of the Near East, a
conclusion resulting from explorations among these
ruins which have been carried on during recent years.
It is a conclusion which is intense!)' fascinating, not
only to the archa?ologist and antiquarian, but to the
Biblical student, for here are to be found the remains
of an enormous gold-mining industry and the traces of
an ancient civilisation, for which Semitic people, most
probably from Southern Arabia, are responsible.

The age of the oldest type of ruined buildings is now
believed to date back contemporaneously with, if not
earlier than, the Solomonic gold period of Holy Writ,
though much later waves of Semitic colonists have
undoubtedly carried on in this territory the enterprise
of their ancestors. It also appears that the most
ancient type of buildings in Rhodesia yields evidence of
Phallic religion, and of the worship of Baal and
.•\shtaroth as described in the Old Testament.

The main objective of these successions of colonists
was that of gold-winning, for the remains of thousands
of gold workings occupy the area in which the ruins
are found. So extensive are these gold mines that
experts believe that gold to the modern value of at
least seventy-five million pounds sterling has been ex-
tracted in ancient times from the reefs of this country.

From the recently-published work* written by Mr.
R. \. Hall, F.R.ri..S., who spent over two years in
exploring the central group of ruins, we gather that
the structures are of various ages covering periods ex-
tending from the most remote antiquity down to
media;va! times.

These buildings, which are admitted to be the
greatest archccological wonder of the Southern Hemi-
sphere, are in groups, but the groups are connected
with each other, and also with the coast at the ancient
port of Sofala, by chains of massi\c forts at a distance
of a few miles from each other, and these forts occupy
strategic points protecting well-defined routes of the
ancients throughout the country. Messrs. Hall and
Neal statet that there are at least some three or four
hundred ruins or sets of ruins throughout the region
of Southern Zambesia, and descriptions of many of
these buildings and of the associated gold workings,
together with information as to the ancient architec-
ture, are set forth in detail.

The most important group of buildings is that of the
Great Zimbabwe, i.e., " the great buiklings of stones."
This is situated some two hundred miles inland west of
the shore of the Indian Ocean at Sofala. Zimbabwe,
both by the size of its buildings, the area covcretl (one
and a half miles by one and a quarter miles), by its
position, appears to have been the chief metropolitan
centre of the ancient gold miners, and is undoubtedly

• " Great Zimhabwe" (Methuen)
' Thi Ancient Ruins 0/ Rhodesia " (Metbuen).

July, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

187

among the oldest type of building to be found in the
country. This group was re-discovered in 1868 by
Adam Renders, an elephant hunter. In 1891 Mr.
Theodore Bent visited the place and described it in his
" Ruined Cities of Mashonaland." But in the days
when Mr. Bent visited Zimbabwe, the whole of the
ruins were in a buried condition, yet so far as he was
able to describe these structures his account is per-
fectly reliable and of permanent value for the anti-
quarian.

During 1902-4 the Government of Rhodesia engaged
Mr. Hall to explore this group of ruins and to take
measures to secure their preservation. The interiors
had, in the course of long centuries, become filled in
with silted soil, the debris of later occupiers, and fallen
walls, as well as rank sub-tropical vegetation. This
gradual filling-up process had led to the burial of the

what extent the ruins had in the course of ages been
covered over. But the area occupied by this group is
so extensive, and the distinct ruins are so numerous,
that these operations, carried on under great dilTiculty
and necessitating the constant exercise of care and
patience during the exploration, still leave the great
bulk of the Zimbabwe ruins buried and unexamined.
It is quite possible that the buildings contain many
more secrets of an important character to be unravelled
by the archaeologist.

The ruins of the Great Zimbabwe consist of three
main sets of structures — (i), the Elliptical Temple with
the conical tower; [2), the Acropolis or Hill Ruins of
bewildering extent on Zimbabwe Hill; and (3), the
Valley of Ruins, these latter being a conglomeration
of smaller ruins of all ages occupying a large area in
the Zimbabwe Valley.

Fig. I. Inttrior of Elliptical Temple, looking East, shjwing Conical Tower.— Qreat Zimbabwe.

ancient floors to a depth varying from six to twelve
feet. With the aid of a gang of native labourers the
work of clearing the interiors of some of the important
portions of the buildings was taken in hand, but the
operations, though carried on for over two years, re-
vealed only a portion of the ruined structures com-
prised within the limits of the " Dead City."

Enough, however, was disclosed to prove beyond
question the past existence of Phallic litholations, and
solar worship of a very old cult practised by the original
occupiers. Not only were entirely fresh features of
ancient architecture discovered, but such of the original
floors as were uncovered yielded priceless relics of pre-
historic times, including gold ornaments and religious
emblems in rich profusion. When it is stated that
thousands of feet in length of narrow and labyrinthine
passages which had become lost to sight were dis-
covered and cleared of debris, one can understand to

The chief archaeological interest, however, centres in
the Elliptical Temple (Fig. i), an object arousing
wonder and even sheer amazement to all who visit
these ruins. Its massive and stupendous walls, grace-
fully sweeping curves, and most excellent workman-
ship and decorative mural patterns, at once rivet the
attention. The plan of the building is elliptical, while
the ends of the walls, sides of entrances, and buttresses
are all rounded. The angular form of building is
absent. The walls are very substantially built of
dressed granite blocks laid without mortar or cement,
and have bases averaging from 7 ft. to 16 ft. in width,
and are beautifully and skilfully constructed not only
on their exterior faces, but in their internal portions.
The walls average a height of from 24 ft. to 31 ft., the
main east wall being 16 ft. wide at its base, but at a
height of 30 ft. its summit is 8 ft. in width. The lean-
back or batter-back of the faces of the wall gives an

KNOWLEDGE & SCIENTIFIC NEWS.

[July, 1905.

Eastern appearance to the building, which is very
striking. The summit of the main cast wall was once
decorated with tall granite monoliths, the bases of some
twenty-six monoliths still remaining in situ. The outer
face of the east wall bears a pattern of chevron in two
rows worked in granite blocks (Fig- 2). This pattern
is one of the earliest decorative designs known to
research, and is the ancient emblem of Water and
Fertility of the old Nature worshippers.

The Conical Tower, 32 ft. in height, is one of the
principal architectural features of this building. Its
lines are worked out with marvellous skill. It is per-
fectly solid, and with it is associated a high stone plat-
form approached by steps. The tower is considered by

Fl(t. 2.-Chci

on Pattern on Eastern W all. IZlMplicol Temple
Great Zimbabwe.

many leading men of science to be identical in purpose,
if not in general form, with the Baal towers of Arabia,
I'hfi-nicia, Canaan, and Babvlon, referred to in Holy
Writ.

The interior f)f this immense building is divided into
some Fifteen enclosures, and there is no less than 700 ft.
length f)f passages within the walls, the most famous
being the Parallel Passage, which leads directly from
the north or main entrance into the Sacred F^nclosure
in which stands the Conical Tower. Many leading
European experts place the age of the Temple at some
period between iCkjo and 1100 B.C.

There is great similarity between the architecture of
Zimbabwe and that of several ancient temples in South
Arabia. The Temple at Zimbabwe is admitted to be

the finest example of an ancient Nature worshipping
shrine known to the world. No inscriptions have been
found at Zimbabwe, the earliest inscriptions found in
anv Phrrnician Temple being not older than 700 B.C.

At Zimbabwe there are evidences of an ancient
civilisation and arts whose only parallel in many re-
spects, especially in their associations, is to be found
in the ancient kingdoms of South Arabia. According
to the Scriptures, and ancient Roman and Grocian
historians, the Sabrcans of South Arabia were the gold
purveyors of the then know'n world. Rhodesia con-
tains the most ancient and most extensive gold mines
yet discovered.

The Gold Mines and
Gold Prodviction.

The history of Africa as a gold producer dates back to
very early times. It was not, however, till compara-
tivelv recently that .South .'\frica, as now known, was
found to be a gold-bearing country. In 1882
the Ue Kaap goldfields were started, while it was
three years later before the famous Sheba fninc was
discovered and the town of Barberton founded. The
existence of gold, however, had long been surmised,
and was actually discovered in 1868, Carl Mauch re-
ferring to it as occurring near the Oliphants River.
In 1870 it was found in the Murchison Range, and the
next discovery was in the Lydenburg district, at
Pilgrim's Rest. In 1884 Struben Brothers started a
5-stamp battery on the farm Wcltevrcden, in the
western district of the 'iVansvaal, for quartz mining,
which is very dissimilar to " banket," as the huge
conglomerate bed of the Witwatei^srand basin has
come to be known. The deposits consist of quartz
pebbles held together by a siliceous cement containing
iron pyrites. The gold exists in the finest particles,
showing sharp crystalline structure on examination by
the microscope, as against the rounded forms, through
attrition, in alluvial deposits. Gold was first panned
from the " Ijanket " beds of the Witwatersrand (or
white waters ridge) in 1885, and in 1886 Johannesburp-,
the " Golden City," sprang into existence, as if from
the wand of a fairy. The goldfield is situated on a plain
about ft, 000 feet above the sea-level, across which the
northern outcrop of the gold basin rises slighllv, and
roughly represents the watershed between the Atl.intic
and Indian Ocerms. The formation h.is been traced
pr.ictii-.iliy continuously for about f.o miles along the
strike of the Main Reef, from Randfontcin in the west
to Holfonlein in the east. A length of about 12 miles
of this, with the Langlaagtc Block B on the west and
Knights on the east, is described as the " Central
Rand," the companies operating which are stated to
be responsible for about three-fourths of the gold won
down to the outbreak of war in i8gg. But the con-
glomerate beds have been traced over far greater areas,
outcrops and borings having revealed continuity for
164 miles, while nearly 150 miles are estim.-ited to be
concealed by recent measures and short interruptions
by faults or dykes. Judging from the dip of the
formation at the central northern outcrop of the basin,
It was for some time supposed that the depth would
become prohibitive for mining at a distance (say) f)f
two miles. Enormous engineering feats will apparently
not have to be undertaken, as exploration has shown

July, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

that the curve between the north and presumed south
outcrops is not symmetrical. In fact, the bed of the
area has a more or less level bottom, being a series of
synclines and anticlines.

Gold mining is everywhere a highly speculative
undertaking, but in the Transvaal great reliance
can be placed upon the regularity of the ore deposits.
This justifies very heavy preparatory outlays. It is,
for instance, estimated that before an ordinary deep-
level mine can reach the producing stage the expendi-
ture on boring, sinking (say) two shafts, the erection
of a mill of 400 to 600 stamp capacity, the connecting
of the two shafts, and driving on the reefs to expose a
sufficient quantity of ore to keep the mill in operation
amounts to something like one million sterling. This,
of course, refers to a proposition where the reef
lies at a depth of about 3,000 feet, while the area
of such a mine would be something like 1,000 claims.
When the ore is " brought to grass," as it is termed,
a series of scientific processes is brought into play in
order to extract the precious metal. The most ap-
proved mechanical appliances and chemical methods
are drawn upon, and the leaders of the industry are
ever on the look-out for improvements, as the nearer
perfection is attained — that is, loo per cent, extrac-
tion— the more profitable is the result. The various
processes are complicated and delicate in the extreme,
and as each particle of gold Is mixed with, perhaps,
60,000 particles of rubbish, as the Transvaal tonnage
averaged in 1903, it can easily be conceived that the
slightest miscarriage would be disastrous.

A great deal of attention has been given within the
past 12 months to tube, or flint, mills. Such a mill
at the Glen Deep consists of an iron cylinder, 22 feet
long and 5 feet in diameter, with hollow trunnions at
each end, through which the pulp to be ground passes
in at one end and out at the other. The trunnions
rest on solid bearings and the cylinder is revolved by a
pulley at a speed of 38 revolutions per minute. The
cylinder is lined with chilled steel, and inside seven tons
of the hardest flint pebbles are placed. The pebbles
are about the size of a tennis ball, and the rounder the
pebbles the better. One such mill can deal with the
coarse product from 20 stamps crushing 10 tons per
diem each. It is estimated that the tube mill will
enable the mill capacity to be doubled at the cost of
;^2,ooo per 20 stamps, or ;£rio,ooo to ;^i2,ooo per 100
stamps, plus the extra cyanide plant and the cost of
something less than 40 h.p. per 20 stamps. Many of
the leading groups are now erecting these secondary
crushers.

The high altitude of the Rand has rendered the ques-
tion of water supply of first importance. The mines
relied upon reservoirs for the collection of a sufficient
supply during the rainy period to carry on mills and
cyanide works throughout the dry season, the Johannes-
burg Water Works doing its best to meet the frequent
deficiencies. But the Transvaal Government ap-
pointed an investigating Commission in 1901, and in
May, 1903, a Water Board was established. The
undertakings proposed to be acquired were the
Johannesburg Water Works, the Vierfontein, Braam-
fontein, and Wonderfontein Syndicates. The last-
named was, however, omitted, as it was thought that
otherwise the irrigation of the I'otchefstroom District
might suffer. The Rand Water Board issued
;^3,400,ooo 4 per cent, inscribed stock in March last.
The Board supplies towns in bulk. The mines are sup-
plied through mains laid along the Rand by the Board

at the rate of 3s. 6d. per 1,000 gallons, and 3d. less
where not less than 300,000 gallons per day are con-
sumed. The rate is not cheap for mines, but when it
gets much beyond its present daily consumption of
two million gallons, a reduction will be possible. The
mines, of course, will not draw upon it until their
private reserves in dams, &c., are exhausted: The
advantage is that no stopping of mills need be feared
now, for it is estimated that about 10 million gallons
per diem can be obtained from the undertakings
acquired.

From the above survey of the Transvaal gold mining
uidustry its magnitude may be g-athered and an idea
obtained of one of the most exact industrial organiza-
tions of the world.

South Africac as at
Health Resort.

Those who have visited South Africa, and made any
prolonged stay there, can hardly fail to be sensibly
impressed with its possibilities as a health resort.

Medical men when ordering a "change," recognise
that the human constitution requires — above all things
—to be subjected to the effects of contrast. In recom-
mending the South African continent, this desirable end
is achieved in the contrasts afforded by a voyage to a
distant land, by climate, scenery, and inhabitants; a
series, making for a cumulative restorative effect.

Climates are classified as follows :— (i), Climates of
the sea-shore; (2), Mountain climates; (3), Desert
climates; (4), Ocean climates. South Africa itself
partakes of the first three; and the invigorating in-
fluences of the last-named may be enjoyed on the voyage
thither.

(a) The climate of the sea-shore of South Africa is
best experienced during the winter months, com-
mencing in April and ending in September; during
these months (in Natal) the season is dry. The climate
is warm, temperate, sub-tropical, sometimes cold; the
warmth, often of a hurnid nature, and for that reason
is, in consequence, more enervating than the South
African continental climates; yet it has its ozonic-tonic
properties. The health seeker will derive great benefit
from a stay at Durban, Port Elizabeth, or even Cape
Town, and at the same time be able to indulge in easy
journeys into the interior of the country, where the air
is more rarefied by reason of the higher altitude. The
best hotels are expensive, but the interests of visitors
are well cared for.

(b) The term " mountain climate " applies to all eleva-
tions between 3,000 and 6,000 feet. Ranging between
these heights are the steppes of Natal, extending in a
series of gradually rising terraces from the sea, and
ending in the majestic peaks of the Drakens-
berg Mountains, the high veld of the Transvaal,
extending to the Magaliesberg Mountains, and the
higher tableland, having the township of Middel-
berg as a centre, and terminating in the north at the
mountains round Lydenburg. Nestling at the feet of
these mountains, and scattered about the kopje-dotted
veld, are the homes of the Boer farmers. The moun-
tain peaks reach as high as 12,000 feet. The climate
of the steppes, high veld, and tableland, is never at any
season too warm, when living in houses, and is gener-
ally dry during the winter months. In winter-time the

I go

KNOWLEDGE & SCIENTIFIC NEWS.

[July, 1905.

air is crisp, clear and invigorating, and the power of
the sun pleasant The nights are cold, as many as 20
degrees of frost having been recorded. In summer at
no time is it insufferably hot. Persons afflicted with an
hereditary tendency to consumption, or those suffering
from overwork in business, will find these " mountain
climates " promise a return to health. The therapeutic
elements of a good climate are these, viz., abundance
of sunshine without excessive heat, allowing of an open-
air life all the year round, pure air, and a temperature
adapted to the requirements of the invalid. To these
essentials may be added the inestimable boon of neces-
sarily conforming to and living the " simple life."

(c) If the characteristic essentials of a desert climate
are advocated, consisting of warmth, dryness, purity of
air, and large radiation, these are found in the
expanses of the Kalahari Desert and Great Karoo.
Probably no country is to be found where an outdoor
life is so practicable winter and summer as in South
Africa, and in which the traveller will find greater varia-
tion of or more majestic scenery. The seeker after
health, who owns a fair amount of muscular power
and activity, will find a long trek in a well-provisioned
ox-waggon, say, through Natal to the Transvaal, a
sure guide to the restoration of full mental and bodi'y
vigour. The features of the scenery encountered are
among the most sublime in Nature, while strikingly dis-
tinct from that of other lands.

NOTES.

Gold-mining and Labour.

When the South African war broke out (October, iSgg), 6240
stamps were providing employment for over 110,000 natives,
and gold was being produced at the rate of /"20,ooo,ooo per
annum. Three companies restarted milling in May, igoi ; but
at the end of 1903 only 64,000 "boys" were at work on the
Witwatersrand, and only 4360 stamps were crushing, out of a
total of 7145 erected. The latter were capable of employing
142,000 "boys" under the best economic conditions, while
30,000 more were required for mines merely in the develop-
ment stage. There was, however, a proved deficiency of
108,000 natives, and moreover it was estimated that within
the next five years a total of 11,000 stamps additional to
those then existing might be erected. The Labour Impor-
tation Ordinance came into force May 19, 1904, and the
first shipment of Chinese as mine-workers arrived at
the New Comet Mine at the end of June, 1904. From the de-
tails supplied by members of the Transvaal Chamber of Mines
and other companies it was shown that unskilled native
labourers in employment at the end of 1904 numbered 77,014,
and Chinese coolies (indentured) 20,396. These, with about
2000 Cape " boys " and Indians, made up a total of 99,623.
The numbers at work on the 31st of May last were: Natives,
96,226; and Chinese, 40,117. At the end of December, 1904,
the skilled and unskilled white labourers at work on the
surface or in the mines numbered 14,173, and the wages bill
came to ;f 4.337.256- At the beginning of June, 1905, the
number so employed was 16,626. On the Rand alone 5555
stamps were in operation at the end of December, 1904, and
during the whole year 8,058,296 tons were crushed, the yield
from the mills, cyanide and other reduction works being
3,638,241 02s. of fine gold, of a total value of ;{■! 5,529,2 19, or
38-46 shillings per ton crushed. In April, 1905, 6665 stamps
were in operation in the whole of the Transv.ial, and a tonnage
of 929,268 was milled for a yield of ;f 1,695,550, as against
a monthly average of /; 1, 337,000 in 1904. The total produc-
tion in the Transvaal to the end of May amounted to
;f 132.765.S70 ; for 1904 the total was ;£■ 16,054,809, or more than
one-fifth of the world's productioD during the year, estimated
at /■7i,898,7i3-

Big Game Extermination,

The greater part of the^country which will be visited by
the members of the British Association possesses special
interest for the naturalist from the circumstance that it was
once the home of a multitude of big game animals, the like
of which was unknown in any other part of the world's regions
within the historic period. Their numbers, however, have
been decimated through the avarice or improvidence of
civilized man, aided in some measure by the native races, fol-
lowing their acquirement of and subsequent familiarity with
the use of fire-arms. Within modern times the tract of
country in South-East .Vfrica where these big game animals
abounded most was probably the plains of Bechuanaland,
the Orange Kiver, and the Transvaal, parts of which formed
the hunting-ground of Gordon-Cumming and other pioneer
sportsmen, but earlier the plains of Cape Colony were popu-
lated by a vast fauna of large and beautiful game animals.
At the conunencement of the Dutch occupation we read of
white rhinoceroses being met with quite close to Cape Town.
The Dutch, however, were not long in perceptibly decreasing
the number of big game in the country ; and one beautiful
species of antelope, the bluebuck, or blaauwbok, seems to
have been exterminated at a very early date. But some
excuse for the vigorous efforts of these Dutch pioneers to thin
out the animals which occurred in such swarms in the newly-
colonised country may be found, for about the middle of
the 17th century we read of their gardens being raided by
elands and kudus, and their larger crops destroyed by the
incursions of rhinoceroses and hippopotamuses ; while on one
occasion a slender garrison was actually iu fear of the fort
being stormed by a frontal attack of lions. Gradually the
game was driven further and further up country, though a
sufiicient percentage remained for the sportsman and
naturalist. It was not till after 1837 (twenty-two years prior
to this the explorer Burchell had crossed the Orange Kiver
and entered Bechuanaland) that the Boers trekked to the
districts now known as the Orange River Colony and the
Transvaal, and, once there, the fierce pursuit of the game,
which, as we have seen, had taken place in Cape Colony, was
repeated, but at a more rapid rate, owing to improvements in
fire-arms, and the operations of the " skin-hunters," who shot
down the animals by tens of thousands, prompted by the
commercial uses to which their hides could be put. Between
the years iS4oand 1875 the destruction of animals in the old
republics, it is safe to say, might be reckoned by millions.
According to report, in the year i860 one specially notable
" drive " was instituted, and for this occasion some 25,000
head of game were enclosed, of which it was computed that
upwards of 6000 were slaughtered. The settlers realised the
market value of the herds of big game with which the veld of
the Orange River Colony and the Transvaal was at that time
swarming, and took full advantage of their opportunities. By
about 1880 a clean sweep of the game had l)een made, and
today one may wander over those same plains which, in
Gordon-Cumming's time, were actually blackened by the pre-
sence of roaming animals, without seeing even a single herd of
game, or, at most, nothing more than a few springbok as sur-
vivors. Nor was the destruction confined to skin-hunting;
ivory was an even more valuable commodity, and so keen
has been the pursuit that there are now but few districts re-
maining where elephant-hunting for profit can any longer
be regarded as pr.aclicable.

From Cape Colony to the Transvaal the effort is too late
for effective game preservation, and all that can be done is to
preserve the scattered herds of the surviving rarer species till
such time as they perish from inand-in-breeding. In
Rhodesia and other neighbouring districts the outlook is more
hopeful, and whatever is possible under existing circum-
stances is being done to ensure the preservation of a portion
at least of the g.ime. As colonisation and civilisation spread,
the wild animals of the country will inevitably tend to dis-
appear, and, however unwillingly, we must face a time when,
notwithstanding international co-operation, a large portion of
Africa will be as destitute of big game as are the more fre-
quented districts of Cape Colony and the Transvaal at the
present day.

igi

Kfiodiledge & SeleDtilie fieuis

A MONTHLY JOURNAL OF SCIENCE.

Conducted by MAJOR B. BADEN-POWELL, F.R.A.S., and E. S. GREW, M.A.

Vol. II. No. 9. [NEW series.]

AUGUST, 1905.

SIXPENCE.

CONTENTS.— Sec Page VII.

The

Sun. in Calcivim LigKt*

By William J. S. Lockver, M.A., Ph.D., F.R.A.S.

I.
Some time ago an account was given in these pages
(Vol. I., p 150), of some of the results which Prof.
Hale had secured with the spectroheliograph he had so
successfully designed and used in conjunction with the
great refractor of the Yerkes Observatory.

This work, as I have pointed out elsewhere, marked
a new epoch in solar physics, for it suggested possible
fields for research which, up to that time, were not con-
sidered within the region of practical accomplishment.
Thus, for instance, it is now possible to determine the
distribution on the sun's disc and limb of such sub-
stances as calcium, hydrogen, iron, and many other
materials, the lines in the spectrum of which are
sufficiently strong in the solar spectrum. Not only can
this question of distribution be minutely studied, but
by securing photographs in different years the variation
of the areas covered by these substances from year to
year can be measured. In this wav we have a method
of estimating solar activity. Again, we are in the pre-
sence of a means of very considerably increasing our
knowledge of sunspot formation because spots give us
only a very brief span in the life history of a disturbed
region, which can now be photographically traced long
before any indication of a spot is detected and long
after the spot itself has disappeared.

Further, a means is now afforded of rapidly securing
the forms and positions of prominences on the solar
disc at one exposure, either by using calcium, hydrogen,
or, possibly, other lines for the investigation. By
successive exposures on any particular portion of the
limb comparatively rapid changes in prominences can
also be photographically recorded.

These and many others are some among the numer-
ous problems that are now waiting investigation by the
aid of this powerful instrument of research, so that
there is plenty of work for those students of Solar
Physics who wish to participate in this field of inquiry.

At the present time there are not many of these
instruments at work, or even in existence. In addition
to those used by Prof. Hale in America, and M.
Deslandres at Meudon, in France, Mr. Evershed, in
England, has been securing some small scale pictures
during the last few years; while at Potsdam another
small instrument is mounted on an equatorial telescope.
At the Solar Physics Observatory, South Kensington,

a somewhat larger instrument than the last two men-
tioned has been at work during the past year, and
nearly a duplicate of this has been despatched to India
and is now in working order at the Kodiakanal Solar
Physics Observatory.

There is e\ery reason, then, to hope that before long
more instruments will soon be erected and set in
operation in order to assist in the accumulation of
material for increasing our knowledge of the physics
of the sun.

Fig. I. The iz^-inch Taylor Photo=visual Lens and Support for form-
ing the Solar Ima^e on the Primary Slit of the Spectrohelio-
graph.

In the following paragraphs it is proposed to briefly
describe the South Kensington instrument and to refer
at no great length to some of the results that have been
gleaned from the photographs that were secured during
the summer months of last year. A more complete
account will be found in the Monthly Notices of the
Royal Astronomical Society (Vol. Ixv., p. 473), in a
paper communicated by me during last March.

Unlike the spectroheliographs employed at the Yerkes
and Potsdam Observatories, where both are worked in
conjunction with equatorial telescopes, the one at South
Kensington is so arranged that the solar image is
formed by a lens (Fig. i), on which sunlight is thrown

ig:

KNOWLEDGE & SCIENTIFIC NEWS.

[A I- GUST, 1905.

by means of a siderostat. In fact, the complete instru-
ment consists of a siderostat to constantly throw the
solar rays horizontally in a due south direction, a lens
to form the image of the sun, and the spectroheliograph
to obtain monochromatic pictures of this image.

The siderostat (Fig. 2) has a mirror of 18 inches
diameter, and the lens an aperture of 12 inches, with a
focal length of 18 feet. The solar image thus formed
has a diameter of 2 i-7th inches, which Is the same size
as that of the monochromatic image photographed.

To secure the latter the optical arrangement is as
follows: — ^^The stationary solar image falls on a slit
plate with jaws, 3 inches lonjj, mounted at the no.'th end
of a tube, while at the other end of this tube is a lens
4 inches aperture and 6 feet focal length; this forms the
collimater. The light, after traversing this collimater,
then impinges on a plane vertical mirror and is reflected
on to a prism. This prism is so placed that the light,
after passing through it, falls on to another 4-mch
object glass of 6 feet focal length, mounted at one end
of another tube similar and parallel to the collimater.
In the focal plane of this objective, in which a spectrum
is formed, a second slit with jaws 3^ inches long is
placed in position. By so adjusting this secondary slit
any particular line in the spectrum can be made to pass
through the jaws by itself. In this way a line in the
spectrum of calcium, or hydrogen, or iron, &c., can
be isolated. The lines of the spectrum formed in the
above manner are not straight but curved, so that it
becomes necessary to employ a slit, the jaws of which
are curved to the same amount. .Such a slit rcf|uires,

Flu. J. (icncral View of the Ijirgc SldtroiUt .,howln)t the i8-lnch
Plane Mirror. The upper porilon of the Mouse Is here moved on
iU ralU towards the north.

in consequence, very careful adjustment, and the means
adopted for placing the jaws in any required position
can be well seen in the accompanying figure (Fig. 3).

By means, then, of the above optical arrangement,
any particular strip of the sun's image which passes

through the jaws of the first or primary slit issues
through the secondary slit as light of one wave-length
or colour.

If the whole spectroheliograph be graduallv moved
across the solar image different strips would enter the

Fig. 3.— The "Secondary" 51it, showing the various Screw-adiust-
.'ments available for setting thecurvedj&wscxactly on the<" K." line.

primary slit, and they would build up a picture of the
sun in one wave-length at the second slit.

In order to produce this change of position in relation
to the fixed solar image, the slits and optical parts arc
mounted bodiiy on a movable platform. This platform
(see Plate i, Fig. i) rests on three balls, each of which
is capable of movement between steel surfaces, the
lower ones being fixed to the upper surface of another
triangular framework supported by three concrete
columns. To ensure timform motion — a very im-
portant consideration — the movement, which is pro-
duced by falling weights, is controlled by the flow of
oil through an aperture, the size of which can be varied
at will. The direction of the motion required, namely,
that in a horizontal direction and at right angles to the
axis of the solar beam falling on the primary slit, is
obtained by pressure of the upper platform against a
guide bar fixed on the lower framework in the correct
direction. The photographic plate, like the sol.ir image
on the primary slit, must be fixed relatively to the
spectroheliograph. This is accomplished by placing
firmly on the concrete column a vertical mahogany slide
into which the plate holder can be placed as close up to
the secondary slit as possible without actually touching
any portion of it.

The method of procedure adopted to secure a disc
picture with this apparatus is as follows : —

The adjustment of the secondary slit to isolate the
centre of the " K " line being made, this slit is closed
to the required width. The primary slit is next placed
in the meridian and the solar image brought by the
slow motions central on the slit. This image is then
carefully adjusted for focus. The shutter holiirul the
primary slit is then closed.

August, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

193

rig. 3. East.

(Tu be continued in our next issue.)

Fig. 2.

194

KNOWLEDGE & SCIENTIFIC NEWS.

[August, 1905.

The Nature of Life.

Bv Geoffrey Maktin, B.Sc. (Lond.).

III. — The Possible Significa>.nce of
Alcohol Drinking.

When- a child I lived in a small town in South Wales.
In the town the people spoke only linglish; in the
remoter country districts the peasants still spoke
Welsh.

The language that these peasants spoke had for me
at that time no interest or significance.

It was a rude, imperfect dialect which was only
spoken by uneducated people.

To me now, in after years, now different appears
that rude peasant dialect ! It signifies for me now the
relics of a by-gone time when this poor dialect was a
great world speech — such as English is now — and these
rude peasants the representatives of a mighty people —
the Kelts — whose armies swept in waves of living
valour from out of Asia into lands so distant as Ireland,
Spain, and .Asia Minor.

Now what has worked the difference in my mental
attitude? Solely increase of knowledge. When a
child I knew nothing of the Kelts nor of their history.
And so it is generally. A treatise on Besscl functions
has no earthly interest for a Matabele warrior; the
mathematical physicist is deeply interested in such a
book; the interest of the mathematician is the result of
a knowledge of the use and possibilities of such func-
tions. The uninterest of the Matabele is due to his
ignorance.

Many matters appear to possess no interest or im-
portance to us simply because of our ignorance. Suit-
ably viewed such facts become pregnant with world-
wide consequences; for example, the blind hates and
bitternesses which exist between peoples of different
races has possibly no particular significance for the
average man, except perhaps as a deplorable fact. To
a scientist these racial hates inspire the greatest
interest, for in his eyes they are but the outward play
of those mysterious organic forces which cause evolu-
tion and the differentiation of species.

The almost universal drinking of alcohol, and the
vice of drunkenness, which exists among all peoples
and in all times of which we have any record, is another
phenomenon of the same kind.

We propose here to review this last matter as a
scientific problem, and gravely consider the physio-
logical reason why men of all animals have this natural
instinct after strong drinks most strongly developed.

Is it the manifestation of some great and imperfectly
understood organic tendency, or is it only of the nature
of a disease?

We prorccfl to discuss this question solely from a
chemical standpoint.

One condition which seems indispensable for the
manifestation of vital activity is fluidity. All living
matter is bathed in fluids and it itself has a mobile
semifluid constitution; all facts point to the conclusion
that the condition of fluidity is intimately connected

with life; it is even said that life first originated in the
fluid sea and thence spread to land.

Certainly the observation that by far the greatest
part of living matter consists of water, either free or
combined, lends strength to this supposition.

The reason of this mobile and semifluid condition of
living matter becomes manifest when we begin to study
its chemical nature. Living matter is a complex
system of atoms in eternal breakdown. The very con-
dition of life seems change. Only in a semifluid
condition can take place that continual redistribution
of matter which, while preserving the form of living
matter intact, supplies that flux of atoms which
counterbalances its continuous decomposition.

Where the external physical conditions as regards
temperature and pressure are such as to render the
existence of matter in a fluid or semifluid condition
impossible, then life as we know it would be incapable
of existing. For example, at very low temperatures,
all matter solidifies and the fluid condition as a phase
becomes impossible. Even the most volatile gases first
condense to liquids and then change to solids, so that
at a temperature approaching the absolute zero we
look out upon a frozen solid world.

The constitution of living matter must therefore be
so adjusted to the external physical conditions as re-
gards temperature and pressure that it continually
maintains this condition of fluidity. When we contem-
plate the history of the world we find that these condi-
tions have in former times been widelv different from
those which at present hold. There was a time when
the world was a white-hot sea, when the moon had
not yet been flung off by some mighty catastrophe from
the revolving glowing mass. As ages passed the
worlJ cooled and cooled, until finally the temperature
conditions which now reign were attained.

But the process of cooling is not finished; the world
is still cooling and there will surely come a time when
the average temperature of the world will sink from its
present value (15" C) to 0° C, to — 10" C, - 100° C,
and finally below the freezing point of hydrogen itself.

Even at the present time the temperature of the
world is only slightl}' above that temperature at which
all the water on the earth \\ ill pass into the solid con-
dition. Indeed the process of solidilicition has already
commenced. Vast regions are found where the water
has already permanently passed into the solid condi-
tion; and the regions will extend with time until the
seas and the mighty oceans themselves will freeze and
be converted from top to bottom to a vast mass of ice.

Water will appear to the inli.'iliitants of future days
as solid deposits of mineral matter, presenting to them
much the same appearance as the white masses of
mariile rf)cks in certain parts of the world appear to us.

At first sight it would appear that the effect this
universal solidificilion of w-ater will have upon the life
of the earth in the form w'e know it will be its absolute
destruction. For with the passage of water into a
solid state the existence of living matter in a fluid or
semifluid condition becomes impossible.

Water is f)ne of the most volatile and important
constituents of living matter; all the tissues are bathed
in watery fluids, and by far the greatest portion of
living matter is actually composed out of water. Upon
the fluidity of water hangs the mobility and fluidity of
living matter as we know it.

It is true that the freezing point of water may be
lowered even to a considerable extent by the addition
of impurities to it. For example, a mixture of water
and salt can remain fluid at temperatures very much

August, 1905 ]

KNOWLEDGE & SCIENTIFIC NEWS.

195

lower than that at which pure water freezes. Yet even
this artificial lowering; of the freezing point of water
will only enable us to stave off for a time its universal
solidification in the tissues and the consequent passage
of living matter into a solid frozen condition.

Were living- matter a rigid unadaptable machine, one
might well look with despair upon the prospects of life
in the coming ages of cold and eternal night. Many
facts we know, however, point to the conclusion that
living matter posseses the power of adapting itself to
changing exter.ial conditions; for example, it is a well-
known observaiion that by gradually raising the tem-
perature of water in which certain organisms live, we
can in the course of time cause them to live and
flourish in water so hot that specimens of the same
organism which had not become acclimatised to the
changed temperature are at once killed when placed
therein. The question is, therefore, in what direction
can living matter change its constitution in order to
adapt itself to temperatures much below that at which
water enters into a solid condition ?

One thing appears certain. If living matter is to
avoid being frozen hard with the falline temperature,
the water as such must be gradually eliminated from
the organism and its place taken by another liquid
which remains fluid and mobile under conditions which
render the existence of water as a fluid impossible.

Now is there any other fluid which perhaps could
take the place of water in living matter and fulfil this
condition? Alcohol seems to be such a fluid; alcohol
freezes at - 130° C, water at 0° C.

Moreover, of all the known compounds alcohol is
the one which approaches both chemically and
physically nearest to water in properties.

Both are mobile fluids; both are great solvents; both
have a very similar constitution — alcohol, in fact, is
water in which a hvdrogen atom is replaced by the
heavier radicle C, H,, thus : —

water.

C-H-'

Alcohol can perform many of the functions of water;
for example, just as water can combine with molecules
to form " Water of Crystallisation," so also alcohol
can, and we can likewise speak of " Alcohol of
Crystallisation."

Moreover alcohol is, like water, though to an enor-
mously smaller extent, associated with living matter.

It is the product of fermentation in enormous
quantity by the lower forms of life, and occurs to a
greater or less extent in fermented ripe plants and
fruits.

It is, therefore, by no means inconceivable that
alcohol could enter into the constitution of living matter
to an enormously greater extent than it does at pre-
sent, and thus replace the water as the fluid which
bathes the tissues.

Moreover, there even seems to be at hand the
mechanism by which such a replacement could be
brought about; certain of the lower forms of life can
manufacture alcohol as a product of their vital activity.

The whole phenomenon of alcoholic fermentation is
an instance of this fabrication.

We have only to conceive that this fabrication of
alcohol takes place to an increasing extent in the living
body itself. These alcoholic ferments can be conceived
to enter as the temperature falls to an increasing extent
into the constitution of living matter, and thus to

gradually increase the store of alcohol in the body itself.
So that when the temperature falls below that at which
water freezes, the watery fluids in the lower forms of
life will have been replaced by fluids in which alcohol
largely predominates, and which, therefore, remain
fluid and mobile at a temperature whereat the plant
would be frozen hard if it contained only water.

The age of water life would thus gradually pass into
the age of alcohol life; and the cause of the variation
would be the necessity for the organism to adapt itself
to the altering external physical conditions by
eliminating a less volatile for a more volatile fluid.

It is in the light of this conception that we approach
the treatment of the question of alcohol drinking by
the human race. It is well known that men in cold
climates drink alcohol in a more concentrated form
than the men of warmer lands.

Coldness, in fact, seems instinctively to drive men to
alcohol. And if the temperature of the world is gradu-
ally reduced, so as to replace a temperate climate by a
colder one, doubtless this tendency would be greatly
intensified.

I can easily imagine a process by which man first
began by drinking only water — as the lower animals do
now; then by drinking water with a little alcohol in it,
as man does now; then as the world grew colder and
colder age by age, the amount of alcohol in the drink
gradually increased until ages hence man will have
evolved into a creature which will drink only alcohol.
Together with the increase in the alcohol in the fluids
man consumed, the quantity of alcohol in the fluids of
the body increased, and the quantity of water
diminished, until ultimately in the course of ages the
constituents of the fluids of the tissues so altered that
the water was entirely replaced by alcohol. The
process of evolution would then be complete; a less
volatile fluid would be replaced by a more volatile one,
by a process probably of the same nature that caused
the less volatile elements such as sulphur, phosphorus
and silicon, to be replaced by the more volatile ones
such as oxvgen, nitrogen, carbon, and hydrogen.

Water would then exist in mere traces in the body,
much as .S does now, as the relics of a bygone time
when it assumed a far greater importance in living
matter than it does at the present time.

Is not this tendency men have to abstain from drink-
ing pure water and to drink instead alcoholic beverages
nothing else than the beginning of the gradual replace-
ment of the water in the human body by alcohol?

Viewed in this light the phenomenon of alcoholism
assumes the greatest interest and importance, as the
possible manifestation of a mightv organic change
sweeping slowly but irresistibly over the whole of living
matter.

It may be, however, that some other fluid — for ex-
ample, an oily liquid such as is found in great quantities
in the bodies of fishes which live in cold seas — and not
alcohol, would be the liquid which will ultimately re-
place water in living matter. Whether this be so or
not, one thing, I think, is almost certain, and that is
that if life is to continue at much lower temperatures
than those which hold normally upon the earth, the
water must be eliminated and its place taken by another
liquid harder to freeze.

'Jt

We beg to call the attention of regular readers to the
new system of Subscription announced on page X.

196

KNOWLEDGE & SCIENTIFIC NEWS.

[AuGi'ST, 1905.

The Irvduction Pump.

WitK Suggestions as to Reversal
in Influence Machines.

Bv Charles E. Benham.

In two previous articles published in " Knowledge"
(November, 1904, and May, 1905) some simple experi-
ments in electric induction were described, the ijeneral
principle of which was that of the original " doubler"
of Abraham Bennet, and also to some extent that of
the majority of devices which succeeded the doubler,
with a view to render the multiplied-charge process
available in a practical way. Such devices include the
machines invented by X'arley, Toepler, Voss, and others,
as well as such modifications as Lord Kelvin's water
dropping apparatus, and finally the admirable arrange
ment adopted by Mr. Wimshurst, and known by his
name.

The multiplying process, by which these machines
acquire such powerful electric charges, is briefly attri-
butable to the fact that while an insulated charged body
can confer, by induction, without losing its own elec-
tricity, successive charges of opposite sign upon two
or more conductors successively earthed when near it,
it can obviously be made to receive in return an increase
of its own charge if it in turn is placed within the in-
ductive sphere of those two or more charged bodies so
that they all re-act upon it simultaneously. This is the
principle that underlies the action of most of the
influence machines, the difference being chiefly in the
way in which this cycle of action and re-action is
brought about.

It was shown in the experiments already referred to
that there are alternative ways of carrying out the
process. I*'or instance, the simultaneous re-action of
two or more inductively charged bodies may be pro-
vided for cither by bringing them into actual contact

with each other by super-position, or by merely placing
the conductor that has to receive their conjoint influence
in an intermediate position so as to be within the sphere
of all of tliem. The latter process lends itself more
readily to practical application. For example, if .i
series of strips of tinfoil are attached to the under side
of a piece of glass, as in Fig i, A, B, C, D, E, they may
each be given an induced charge by the single piece of
insulated tinfoil F, on the upper side of a similar glass,
if this plate is drawn successively over A, B, C, D,
and E, earthing each as the front edge of F passes over
it. Then, placing the plate bearing F over the other,
and touching F, it receives from A. B, C. D, and E a
combined influence, increasing its original charge. On
repeating this cycle a few times the tinfoils, which
had no measurable initial charge, become strongly elec-
trified, the sign of F's electricity being the opposite of
that of A, B, C, D, and E. Reducing the experiment to
a still simpler form, the tinfoils A. B, C. D, and E may
Ix? dispensed with, and the finger mav be placed on the
under side of the plain glass instead, drawing it along
as F is moved, so that it successively occupies the posi-

tions of A, \i, C, D, and E (see Fig 2), and it will do
duty for the tinfoils. The charge is retained by the
glass surface, and after a few strokes from end
to end, alternated with earthings of the upper tinfoil,
Ihe charges will accumulate. There is no need to move
the upper plate at all during the charging process. Let
it rest on the plain glass, and draw the outstretched
finger lightly over the under surface of this several
limes, each time touching the upper tinfoil after the
operation, and a considerable charge will accumulate
on the upper plate and will be given off by its tinfoil
when the two plates are parted and a conductor is pre-
sented to the upper one. Tliat the charge is not due to
friction from drawing the finger over the lower glass i.^
evident from the fact that sometimes the charges will
be positive and sometimes negative on the upper plate.
This variation of the polarity is very curious, and it
is difficult to associate it with a definite cause. Two
sucli pairs of induction plates may be made exactly alike,
and kept near each other under precisely similar con-
ditions. On testing their action at different times the
upper plates of the two pairs will sometimes be found
oppositely chaigcd and sometimes similarly. A numbc
of observations made at varir)us limes of the day, and
under various atmospheric conditions, failed to show
any agreement of behaviour on the part of the two pairs
of plates. .Somct rnics they would retain the same
polarity for several days. .Sf)mctimes one would change
c\ery few hours and the other would continue constant
for a long w hilc. At other times each would vary at very
short intervals, and f)ccasionally one would be so in-
..onstant that it was difiTicult to make it acquire an accu
mulated charge. In 70 observations taken at variouj
times of the day during the space of a week, the upper

August, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

197

plates of the two pairs of inductors g:ave the following
results : —

First pair. Second pair.

43 times neg'ative. 53 times negative.

26 times positive. 17 times positive.

I time variable.

The induced charge of the upper plate was thus more

frequently negative than positive in both cases. If the

charge had been due to friction by drawing the finger

along the under plate, that plate, being well coated with

shellac, would have been charged negatively, and the

induced electricitv' in the upper plate would have been

positive, showing again that the charge could not have

been initiated by friction.

As is well known, the Wimshurst machine, or any
other self-exciting influence machine, is in the same way
variable as to the polarity it will assume at starting
after it has been left at rest for some time.

Returning now to the experiments described in the
two former articles, the object of the present contribu-
tion is to explain how the same process (briefly recapi-
tulated above) mav be utilised more effectively for

Fig. 3-

pumping up from the earth really practical supplies of
electricity; how, in fact, a machine may be made on
this principle, and incidentally how such a machine as
the Wimshurst is a contrivance of this very character.
In the Wimshurst the disposition of the brushes and
oppositely rotating discs gives, as was shown in the
first article, a double multiplying arrangement of char-
acter similar to that which we have performed by hand
more tediously in the experiments that have been
described in this and the preceding articles. It follows,
indeed, that two oppositely rotating discs, with
sectors, as in the \Mmshurst, ought, theoretically, to
become charged with electricity of opposite sign with
only a single brush to each disc placed as at A and B

.\ moment's consideration of this diagram will show
that the directions of rotation of the respective discs
being as shown by the arrows, the sectors successivel;,
charged by induction at the brush A will (two or three
of them at least) re-act simultaneously on the other plate
at B, when they have travelled to the position in front
of that brush. Inversely the sectors charged succes-
sively at B will several of them act simultaneously upon

the sector at \, when they have reached that spot. .4t
A and B, therefore, there will be two points at which
continually increasing induction charges of opposite
sign will be received. It will be found, indeed, that,
arranging the Wimshurst apparatus in this way,
with only two brushes, theory- is exactly borne
out by experience. Tlie brushes promptly glow,
and the two discs are oppositely charged. it
is this latter fact, however, that renders their
charge unavailable under such conditions. The
opposite charges of the two discs hold each other
''bound," and consequently the collectors are not able
to draw off any charge from the plates when arranged
in this way with the two single brushes. The four
brushes of the Wimshurst provide for opposite charges
on different parts of each disc, with a consequence that
at certain parts of the revolution (where the collecting
combs are placed) the adjacent part of each disc is
charged with electricity of the same sign, and this, of
course, is not " bound," but is readily taken off by the
collectors. It is in this way that the Wimshurst
machine is so efficiently adapted to its purpose, the
charges being " bound " at such portions of the revolu-
tion as is appropriate, and set free only at such portions
as are necessary for collection of the charge.

It is, however, obvious that if it were possible to

Fig. 4.

liberate the "bound" charges on the two discs
arranged with the two single brushes as shown in Fig
3, we should have an efficient accumulator capable o'^
charging jars, as in the case of the Wimshurst.

This liberation can be effected by providing that a
portion of each disc shall be removed from its com-
panion's influence. If, for example, the discs are
placed as in Fig 4, the induction can still be effected
by placing brushes at A and B, where the discs over-
lap, while the collecting can be accomplished at the free
parts of the discs, viz., at C and D. It will be necessarv',
however, in order that the sectors may travel past each
other in opposite directions, that the discs themselves
should both rotate the same way, as shown by the
arrows in the diagram.

This device is a true induction pump, drawing, in
chain pump fashion, from the earth contrary electrici-
ties in each of the respective discs with its circle of
sectors.

Two discs of 16 inches diameter arranged in this
way, with 24 sectors on each, will give a torrent of
5-inch sparks, and the machine is readily self-exciting.

A troublesome, and perhaps unexpected, difficulty,

KNOWLEDGE & SCIENTIFIC NEWS.

[Al'gust, 1905.

however, occurs, which must be g-ot over if the machine
is to be of practical service — the tendency to a reversal
of polarity during- working-. The remedy is easily pro-
vided by placing- additional brushes to touch the sectors
.-ifter they have passed the collector brushes; that is, at
the top of one disc and at the bottom of the other. The
reason for this will appear presently when reversal has
been explained.

The defect of reversal is one that occurs more or less
in nearly all influence machines except the W'imshurst,
and the cause, though extremely simple, seems to have
escaped general detection, so that much more mystery
has been attached to it than is necessary.

Reversal is an obvious consequence of the induction
which each charged disc exercises on its own earthed
sector — the "self-induction " of the disc as it may be
called. Each sector, at earthing, is under the influence
not only of induction from the opposite disc, but also
of induction from the contiguous surface of its own disc,
and as the charge increases this inductive influence
from its own disc at last overpowers that from the
opposite disc, and .so effects a charge of reversed sign.
Holtz's memorable observation that when a metal comb
is drawn over a highly charged glass plate a charge of
opposite sign is left on the glass is only a special case of
rif-induction with consequent reversal.

The most satisfactory wav to prevent this self-induc-
tive influence would obviously be to keep the electrici-
ties of each disc " bound,'' except at the collectors.
" Bound " electricity does not induce a charge in
adjacent bodies. It is only when electricity is free that
It is competent to do this. Now, as has already been
pointed out, in the Wimshurst machine the electricities
of ea6h disc are held " bound " except at the collectors,
and that is why self-induction, with consequent reversal,
does not occur in the Wimshurst except under vei-;-
strained conditions, while with the \'oss and most other
influence machines reversal is a constant source of
trouble.

In the induction pump, which has been described
above, the sectors of the overlapping portions of tho
disc have their charges " bound," and these are, there-
fore, incompetent to produce self-induction, but th:
sectors that precede the induction brusiies are charged
with free electricity, and it is when their charge is great
that they are able to induce a reversed charge. To
prevent this the additional brushes have to be provided
as already described in order to neutralise the sectors
at these portions of the discs' orbits.

There is one possibility with regard to self-induction
that is worth considering, viz., the possibility of render-
ing it of .<.er\'ice instead of preventing it as a hindrance.
It is well known that Holtz turned it to account by
utilising the charge of opposite sign which he found
was left on a charged plate after passing a metal comb.
A suggestive parallel to the self-induction of a charged
di.sc occurs in dynamical electricity in the phenomenon
named by Faraday the " self-induction " of the coil, i.e.,
the inductive influence of each winding of the coil on
the next winding. The question is whether, as in that
case the self-induction of the coil is made to produce
the " extra current," in some similar way the self-induc-
tion of the disc might not be made to produce "extra
charge," and so made advantageous to the output. To
effect this a machine totally different in construction
from any of the present influence machines would have
to be devised, but the problem is worth considering in
view of the advantages which influence machines offer
over the induction coil for X-ray work and even for

vlrrlrcc tr-Vgraphy.

The Great Meteorite of
WilloLmette.

.\ FL'LL and interesting description is given in Cosmos
of this meteorite, found in the hills of Western Oregon
in 1902, and we reproduce one of the illustrations.
This clearly shows the peculiar honeycombing of the
base, the cause of which has been a matter of some
speculation. The conditions contributing to affect the
surface of the meteorite are peculiar. The air in front
of it, during its rapid progress to the earth, is com-

f^^

^^^US^^,:^^:!^^

'•^.y^w-y

pressed to such an extent that it becomes almost like
a solid body. The speed attained is calculated to be
something like 50 miles a second. The friction should
generate a temperature of about 5,000° Centigrade,
sufficient to melt any material of which the meteorite
is composed. This is mostly iron, with a small amount
of nickel. The deep holes and furrows in the stone
are, however, more probably the result of disintegra-
tion through chemical and atmospheric action on the
earth. The meteorite, which is 10 feet in greatest
length, weighs i^i tons.

"A R^aised BeaLch irv Anglesey."

To THE Editors oi- " Knowlf.dge."

Dear Sirs, — In your issue for July last. Prof. Hryan, F.R.S.,
refers to what he calls a " raised beach " restiiiK upon boulder
clay between Beaumaris and Penmon, AhkIcsi y.

Reds of sand similar to that described l)y Prof. Bryan can
be seen at Llanddona. Ceinaes, and other places round the
coast of the island ; and at Towyn Trewan, Aberffraw and
Newborou{;h larfje tracts of land have been covered with sand.
But surely these sands cannot be called " raised beaches " in
any other sense than that of having been raised by the wind.

.1 do not doubt the facts mentioned by Prof. Bryan, but w<!
must get stronger evidence than that of these "r.-iised
beaches" to establish the conclusion that "changes have
taken place in the level of \\u: earth," especially when we arc
dealing with a portion of the earth that has clearly been
remarkably stable all along the geological ages from Pre-
Cambrian limes to the present.

Vours faithfully.

W. Edwards,

University College, Aberystwyth, July 24, 1905.

August, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

199

The Simplest Kind of
ProtoplsLsm.

A Note on the Free Growth of Bacteria and Torula;ina solution
of Neutral Ammonium Tartrate in Distilled Water.

By H. Charlton Bastian, M.A., M.D., F.R.S.

In his work on " The Structure and Functions of Bac-
teria," Prof. A. Fischer places the nitrifying Bacteria
that were discovered and isolated in 1888-91 by Wino-
g'radsky among his group of " Prototrophic Bacteria.''
He says their life-processes are "characterised by an
extremely primitive metabolism — a physiological humi-
lity which shows them to occupy the very lowest rung
of the ladder of life." While on another page* he says
the materials from which they build up their cells are
" inorganic compounds of the very simplest character,
carbon dioxide and ammonia, or nitrous acid, with a
few mineral salts. They are thus prototrophic in the
strictest sense of the word, for a simpler synthesis of
proteids than theirs is scarcely conceivable." He
further says : — "As might be expected in the case of
organisms with oxidising functions, all the nitrifying
Bacteria are aerobic. They require no light, and yet,
in spite of this, are able to assimilate the CO2 of the
atmosphere. ' '

His other two groups of Bacteria are supposed to be
absolutely separated from this primitive group : the
"Metatrophic Bacteria," under which are included most
of the known forms, because they "cannot live unless
they have organic substances at their disposal, both
nitrogenous and carbonaceous "; and the " Paratrophic
Bacteria," because thev "can exist only within the
living tissues of other organisms," that is, as true
parasites.

It is the object of this article, however, to show (i)
that a sharp distinction between these first two groups
does not exist, seeing that common " Metatrophic Bac-
teria," as well as some Torulae are capable of taking
on life-processes even simpler than those shown by any
of the hitherto described forms of tlie "Prototrophic
Bacteria" ; and (2) of showing further that such simplest
of all life-processes are not of srobic type.

The verification of these statements can be easily
made. It w^ill only be necessary to prepare solutions
of neutral ammonium tartrate in distilled water, using
about 0.65 of a gramme of the salt to 30 cubic centi-
metres of the water (that is ten grains to^ the ounce),
and often the crvstals have been dissolved to add to one
of the solutions a single drop of a recently prepared
turbid hay infusion, and to another a single drop of a
recently prepared turbid infusion made from beef
or mutton. The two solutions thus inoculated with
common active Bacteria may then be placed in the dark
within an incubator, maintained at a temperature of
300 — 320 C. (860 — 890 F.). In about 36 hours both
fluids will be found to have become slightly opalescent,
owing to the growth, as the microscope will show, of
myriads of minute Bacteria, and occasionally of a num-
ber of very minute Torulje.

Though these common Bacteria and Torulse are thus

capable of growing freely in the saline solution without

the aid of light, I have found that light distinctly

favours the process, since solutions similarly inoculated

• Loc. Cit. Truiishi , 1900, pp. 48 and 106.

and left exposed to ordinary daylight have become
turbid rather more quickly, even though the tempera-
ture to which the solutions has been exposed has been
about 1 1° C. (20° F.) lower than that of the incubator.

In order to get rid of the complication caused bj
the presence e\en of a single drop of an organic infu-
sion, such as was present at first, other solutions may
be inoculated with Bacteria taken from one of the
originfd solutions after five or six days, when their
turbidity has become more marked. As the Bacteria in
these solutions are probably less numerous and less
vigorous than those in the organic infusions, three drops
yrather than one) are now introduced into each of two
other freshly-prepared ammonium tartrate solutions,
one of which may be placed in the incubator as before,
and the other left in a corked flask exposed to daylight;
and at the lower temperature. The growth of these
less vigorous Bacteria is now decidedly less rapid, and
seems only capable of occurring at all freely when
aided by daylight. In the flask on the table the fluid
will become slightly opalescent in four or five days, and
this opalescence increases for a few days, when a sedi-
ment begins to form. But the fluid in the incubator
may show no distinct opalescence, even for a couple of
weeks or more, though a very minute amount of sedi-
ment will accumulate.

Examination of the sediment taken from one of these
second inoculation flasks which has been exposed to
daylight will show masses of Bacteria, mixed with
Torula; or other Fungus spores, together with a deli-
cate, much-twisted mycelium, as shown in Fig. i.

So far there is nothing to show that the Bacteria and
Torulai which grow freely in the simple ammoniacal
solution are not — as "Prototrophic Bacteria" generally
are said to be— a?robic organisms taking their CO 2
from the atmosphere. That point, however, was
settled by me as long ago as 1871, when I showed''
that a solution of the same kind in a flask with a
narrow neck might, with the aid of an air pump, be
boiled at a temperature of about 900F. (so as not to
injure the organisms already contained in the fluid), and
when the air had thus been expelled, the neck of the
flask might be sealed during ebullition, by aid of the
blow-pipe flame. Experiments conducted in this way
showed that in the course of a few days the fluid's
became opalescent in the usual way within these sealed,
airless flasks, and the microscope revealed the usual
swarms of Bacteria. There was no mention in diese ex-
periments of Torulae having been found — though I
have little doubt that some of them were also present,
as these organisms are well known to be generally
anaTobic in their mode of growth.

My claim that the organisms growing in this solu-
tion of ainmonium tartrate in distilled water are build-
ing up protoplasm in the simplest known manner may
be objected to on the ground of the ultimate orgajii'c
origin of the tartaric acid, but I am told by Sir \\'illiam
Ramsay that " ammonium tartrate can be synthesised
from inorganic material, and this substance' is, so far
as we know, absolutely identical with ammonium tar-
trate derived from tartaric acid extracted from wine-
lees."

Seeing that the formula of neutral ammonium tar-
trate is (NH4)2 C4 H4 O4, if there were no impurity
in the solution, the inicro-organisms would have to
build up their protoplasm in some way with the aid only
of C, H, O, and N — which seems almostr incredible. I
may say that the ammonium tartrate used was specially

'The Modes of Origin of Loicest Organisms, p. go.

KNOWLEDGE & SCIENTIFIC NEWS.

rAuGusT, 1905.

prepared for me, some years since, by Messrs. Hopkin
and Williams, and that the solutions were made in
small flasks of hard, Bohemian glass. Such solutions
were formerly twice analysed for me by a skilled
chemist, who reported that not the least trace of either
sulphur or phosphorus could be detected. Sir \\'iHiam
Ramsay has, however, been kind enough to analyse
another specimen of the solution for me after it had
l>een in the flask for five days* and his report is that
the "liquid contained an excessively minute trace of
sulphur, probably as sulphate; but no phosphoric acid
could be detected by the molybdate of ammonium
test."

Looking, therefore, to the fact that the nitrifying
Bacteria would have at their disposal the "few mineral
salts" referred to by Fischer, we may safely assumt
that the micro-organisms growing in this solution of
ammonium tartrate, contaminated only by an "exces-
sively minute trace of sulphur," have, in reality, been
building up the simplest known variety of protoplasm.

Fl». I Ix 37SI.

But how much the process would be aided by a little
phosphorus may easily be shown by the addition of
three grains of sodium phosphate to the solution. An
inoculated ainmonium tartrate solution with this addi-
tion will become turbid more quickly, and will soon
yield a far larger amount of micro-organisms.

This subject seems to me one chiefly of biological
and chemical interest, and to be of altogether less im-
portance on its botanical side. Looking to the nature
of the primary inoculating material, it was only to be
expected that several different kinds of common Bac-
teria would be found growing in the .solutions, and this
has proved to be the ca.sc. Dr. Gordon Holmes, the
Director of the " Research Fund " at the National
Hospital, kindly made a gelatine plate-culture from a
second fluid, the first having been inoculated with a
drop of a turbid hay infusion, and he reports that there
were at least seven different kinds of Bacteria found
— Cocci, Diplococci. Bacilli, and a kind of Streptothrix;
while a miroscopical examination of some of the sedi-

* The Solution was one which had been inoculated with three
drops from a first solution, and, having been in the dark incubator,
it showed no trace of opalescence.

ment from the same flask showed, in addition to
abundance of Bacteria, a large number of Fungus
spores, togetlier with a peculiar spiral and twisted
mycelium, such as may be seen in Fig. i.

It certainly is very remarkable that these common
micro-organisms, previouslv c.irrying on their life pro-
cesses in organic infusions, should be able so rapidly
to adapt themselves to an entirely different metabolism.
It is much to be desired that some skilled chemists
should take the matter up, and endeavour to throw
some light upon the steps by which this marvellously
simple synthesis of living matter is brought about.

StoLr MsLp.— No. 6.

Leo, Cancer.

This map may be of special interest this month, since it
shows the region in which the Sun will be at the time of
the eclipse on August 30. The Sun's K.A. (on the
Ecliptic) will then be X. h. 32 m., so that it will be close
to p Leonis, and within about 7° of Regulus. Mercury
at that time will be within 4^^ of the Sun, S. of 48 Leonis.
\'enus will also be within the map, on the borders of
Gemini and Cancer. Dec. 19° 57' 40".

In the upper left-hand corner are some of the principal
stars of the Great Bear, while to the right lay the
"Twins," Castor and Pollux, and lower down is Pro-
cyon.

Among the more specially interesting objects included
are —

o Geminoriim (Castor) VII. h. 28 m. + 32° 5'. A com-
plicated system. A double star, magnitudes 2-0 and 2-8,
distant ^"-y. One of these stars is also found to be a
spectroscopic binary with a large dark companion, while
a smaller and more distant star shares in the proper
motion.

a Canis Miiwris (Procyon), VII. h. 34 m. 4-5" 28'. Mag-
nitude 0'5. Has a faint but massive companion star,
which was one of the first " dark " stars discovered (in
1840).

f Cancri, VIII. h. 6 m. -t- 17° 59'. This is another
complication of several stars. Two stars of 5 and 5"7
magnitudes revolve around one another in 60 years at a
distance of less than i". A third star, of 5-5 magnitude,
revolves around these in an opposite direction, and accom-
panying this is a dark companion.

e Hydra:, VIII. h. 42 m. + 6° 50'. A triple star. Two,
of magnitudes 4 and 6, are only o"m3 apart, and present
a yellow colour. The third star, of 7th magnitude and
distant 3"'47, is blue.

a Leonis [Regulus), X. h. 3 m. -f 12'' 25'. Magnitude

'■3-

y Leonis {Algeiba), X. h. 14 m. -f- 20" 19'. A double
star, magnitudes 2 and 4, distant 3"-8. Yellow colour.

f Ursa Majoris, XL h. 13 m. -f 32" 6'. A double
star of 4th and 5th magnitude, distant 2"-3.

Leonis, XL h. 19 m. -f 1 1" 5'. A double star, yellow
and blue, distant 2"- 17.

1830 Groombridge (mag. 6-4), XL h. 46 m. -f 51'' 30',
has the greatest proper motion of any star, amounting to
3"-98 in K.A. and -f 5"8 in decln.

In the centre of Cancer is the large cluster, not nebu-
lous, known as Pra;sepe, " the Manger" (I'tolemy), or,
according to some authorities, the " Beehive." Visible
to the naked eye as a small cloud. Forty-five stars have
been definitely located.

Siri'PLEMRNT TO " KnOWLEDGK & SCIENTIFIC NeWS," Allf}llM, 1905.

MAP No. 6.

MAPI

BRIGHTNESS.

1st Mag.

2nd

3rd

4th

Sth

6th

Variable.

Nebula.

MAP No. 6.
Leo, CaLncer.

August, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

201

The IrvternaLtionoLl
Ornithological Congress

By W. 1'. I'VCRAFT.

The Fourth International Ornitholog-ical Congress
ended on June i7tli, a really memorable session. The
standard of papers presented was a high one, and
though, perhaps, striking originality of thought, save
in one or two cases, is not conspicuous among them, yet
almost all show the grip of the specialist, a thing much
to be desired, if the specialist have the knack, which
many certainly do not have, of making himself intelligi-
ble to his fellow-workers in other fields.

Of the President's address we can say but httle, for the
President himself said little, rightly remarking that this
could best be digested after its appearance in print. He
chose to divideyhis discourse between two very different
subjects — the history of the foundation and progress
of the British Museum, with especial reference to the
department of natural history, and of ornithology in
particular, and that very fascinating theme, geo-
graphical distribution. Though many of us were aware
that the nucleus of the present British Museum began
with the acquisition of the collection of Sir Hans Sloane,
probably few know that this was purchased, with Mon-
tagu House designed to hold the collection, by means
of a lottery. Yet such is the case.

After the address came the appointment of Presidents
of Sections, and in the afternoon the real work of the
Congress began.

Of the many papers read, a large proportion were
necessarily of a very technical character, yet every sec-
tion was well attended.

It is curious that only two papers were read which
dealt with museums in regard to ornithology, and of
these only one was professedly devoted to this subject.
This was submitted by Mr. Frank B. Chapman, of the
American Mu-^eum of Natural History, New York. He
dealt with the question, " What constitutes a museum
collection O'f birds? " Helpful and suggestive, it was
rendered yet more useful by a series of beautiful lantern
slides, and these, it is to be hoped, will form the illus-
trations to his paper. In the course of his remarks, he
referred in terms of the highest praise to our own
Museum of Natural History, which, he said, he regarded
as the most perfect institution of its kind which he hail
ever seen.

Besides this, Mr. Chapman read two other papers —
"A Contribution to the Life History of the American
Flamingo" and "A Contribution to the Life History
of the Brown Pelican.'" These two essays were of quite
remarkable interest, and were illustrated by a superb
collection of slides. They were, indeed, models of how
" bird-watching," as some would have us call observa-
tion of this kind, should be done. The papers of Dr.
Willson and Mr. Bruce on the results of their ornitho-
logical work in the Antarctic formed no less striking
proofs of what can be done in the field by men who
are trained to observe. Tlie testimony to the strenuous-
ness of the struggle for existence, indeed, has never been
more graphically demonstrated than by Dr. Willson on
this occasion.

Dr. Dwight (New York) contributed two extremely
interesting papers on peculiarly difficult subjects : —
"The Significance of Sequence in Moults and
Plumages," and "Some Phases of Wear in Feathers."
These are subjects which promise to yield a good har-

vest to the patient investigator, yet in this country they
have received but scant attention, though some of our
commonest native birds illustrate many of the more
remarkable exceptions to the general rule of moults and
the phases of immature dress. How many, for example,
of our field ornithologists could describe the phases of
plumage which the gannet passes through before
attaining maturity?

Mr. J. L. Bonhote gave an admirable summary of the
experiments he is conducting on the hybridization of
ducks, illustrated by lantern slides. Though too com-
plex for the majority of his hearers to follow, when pre-
sented with the facts in the necessarily rapid survey he
was compelled to give, yet all agreed that these experi-
ments had yielded very substantial results.

Bird protection very properly came in for its share of
attention. This very difliicult problem was discussed
from many points of view. Mr. Digby Piggott gave a
lucid summary of the ridiculous anomalies to be found m
our present system of legislation, while Mr. Frank
Lemon gave an equally helpful and thoughtful paper on
the " Rationale of Bird Protection," which gave rise
to considerable discussion.

For the first time, we believe, in the history of the
Ornithological Society, "aviculture" found a place in
its deliberations, Mr. D. Seth-Sniith reading a most
useful and instructive paper on " The Importance of
Aviculture as an Aid tO' the Study of Ornithology."
This was undoubtedly a valuable contribution to a most
neglected subject.

But, perhaps, the great feature of the Congress was
the lecture by the Hon. Walter Rothschild on " Extinct
and Vanishing Birds." This will long be remembered
as a masterly exposition of a very difficult subject, illus-
trated in a manner absolutely unique in the annals of
ornithology.

To hear the lecture the whole Congress was conveyed,
by the generosity of Mr. Rothschild, by special train to
his museum at Tring Park. Here, in a large hall, were
gathered together a vast collection of birds, either
already extinct or fast becoming so, and these were
inspected after the lecture.

Among the more remarkable of these exhibits were
skeletons of the Moa and .^pyornis, as well as eggs of
these birds, and stuffed examples of the rare Labrador
Duck, Black Emu of Kangaroo Island, and the starling
of Reunion (Fregilupus). Of the Dwarf or Black Emu
only two skins are known. The number of birds in
danger of extermination is unfortunately a large one,
and this was painfully evident from the number of speci-
mens displaved here. To make this collection more
perfect Mr. Rothschild enlisted the services of some of
our best known bird artists to prepare coloured restora-
tions of some of the more striking forms which he was
otherwise unable to illustrate. Among these we must
specially refer to a really wonderful restoration, in oils,
of the small Dinornis by'Mr. G. E. Lodge. Mr. Frohawk
contributed three striking pictures to this number — a
Moa 15 feet high, the Giant Rail Lcgiiatia, and the
Solitaire.

But the end of the Congress is not yet. Though
officially over on Saturday, June 17th there remahi at
the time of writing three very important items to fulfil --
the excursion to Woburn .\bbey to see the collection of
wild animals kept by his Grace the Duke of Bedford, the
visit to Cambridge, and the trip to Bridlington to visit
the breeding cliff's of the guillemots. With this last, the
most successful of the Ornithological Congresses yet
held will come to a close.

202

KNOWLEDGE & SCIENTIFIC NEWS.

[August, 1905.

Sea. weeds :

A HolidaLV Pamper for Field
Bota.nists.

By David W. Hevax, Scarboroug^h F.\. ScK'iety.

Most botanists will, during their summer holidays, stick
to the cliff and sand dune to seek maritime, not marine,
plants. But it seems a pity that the latter should receive
such scant attention. The beauty of many of the sea
weeds is so exquisite, the way of life of others so inter-
esting, that the field botanist cannot afford to miss
them, and this is specially the case if he possesses a
microscope. .\ shore that possesses a rocky reef, laid
bare twice daily by the ebbing tide, is the best collecting
ground, and as this article is penned at Scarborough it
may not be out of place to mention that it is an ideal
place in this respect. Arrived on the scene with a tin
canister or two — a bottle of sea-water is also needed, but
should not be carried on the slippery rocks — we proceed
to take " snippings" of everything we come across.

It is noticed at the outset that the seaweeds tend to
be clannish. Tlie green ones favour, on the whole, the
part towards high-tide mark, and the brown the part
between tide mark.s. .\ good many red flourish there,
too, but as a rule their red is a very poor red — nearlv
black or faded yellow. It is mostly in the deepest pools,
and out in those deeper reaches that are never laid bare
by the tide that those splendid crimsons and rosy reds
occur that arc the typical colours of the red seaweeds.
To get these last we must wait till a storm tears them
from their moorings and casts them on the shore.

ITie brown seaweeds are the giants of the shore, and
claim our attention very much, for they are slippery
cu.stomers. Growing on the margins of all the pools
are the Wracks {Fuciis), all of which branch, by re-
peated division into two (dichotomy), much like the
flowering stalk of the Stitchwort, but always in the
same plane, so that if we spread a plant out on the
sand it forms a perfectly flat, fan-shaped frond. 1 ho
Bladder Wrack (F. vesiculosus) has paired bladders
in the frond (Fig. i). The Serrated Wrack {F. serratus)

Pig. I.

Fisr. 2.

is without bladders, and has, as its name indicates, a
saw-like edge to the frond (Fig. 2). The Knotted Wrack
(F. nodosus) is "all stalk," with big bladders in the
stalk like a string of oval In-ads. and its frond has no
flat, leafy expansion or blade. It does not divide
dichotomously, and in other respects, stated further on
it differs from the typical Fucus (Fig. 3). This olant
seems particularly happy in tidal river mouths where

the water is only slightly salt. F. canaliculatiis has
channelled Ironds, and grows only three to six inches high.
Then there is the fine, bushy Sea Oak {Ha/idrys
siliqiwsa) in great plenty in the deeper pools, known by
its pod-like bladders, which are seen, on being split by
a penknife, to contain several storeys (Fig. 4). Lastly,

not to stay among the Wracks too long, there is the
delightful .Sea-thong (Himanthalia lorea), growing at
dead low-tide mark. There they grow in scores — well
worth a snap-shot — like little brown mushrooms when
young, but in their second year they put out a long
strap-shaped dichotomous frond from two to three feet
long, which is the reproductive part (Fig. 5).

Here at low water we see the Tangles (Laminaria
digilata), a stout st.ilk which may reach three feet

long or more, bearing a broad fiat ma.ss of ribbons on
the top. This upper frond is shed in spring and a nev/'
one grow.s there and splits into ribbons in due course.
One sometimes finds both old and new fronds on the
one stalk (Fig. 6).

The most interesting thing .ibout the l-'ucoids is their
reproductive arrangeinents. Everyone has noticed the
swollen ends of the fronds of the Wracks beset with

August, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

203

tiny holes. These holes are the conceptacles. inside
which the eg^gs and sperm are formed. Though most
plentiful in early spring- they are to be found all the
year round. The fronds with bright orange tips are
male and the dull brown ones are female.

Now, on a bright day when the tide is out we cari
easily find tiny drops of brown or orange jelly which
have issued from the conceptacles. The one kind con-
tains the ova, the other the male elements, and it is
now our business to bring these together under the
microscope. It is best to break off the tips of the fertile
fronds, keeping the sexes separate, and lay them on
two dry saucers, placing them in a good draught for
some hours. A plentiful supply of mucilage will appear,
and if a little of the brown is now added to a single
drop of sea-water on a glass slip and examined with a
low power, a very pretty sight presents itself.
Numerous bags (oogonia) of ova, eight in a bag, are

• >- 1

\^^ "^

'>9)i

^~^ iV

■■\ V

[M'

§:.

FUCUS. (I. I Oogonium legg-casei. 6 cf the 8 ova are visible.
(2.) Antheridium with 5permatozoa.
(3.) A discharged egg cell with 4 spermatozoa attacking it.

lying about (Fig. 7). But the rising tide (represented
by the drop of sea-water), begins to act on them; the
wall of the oogonium disappears, and out float eight
beautiful round brown eggs.

W'tien the orange-coloured jelly is similarly treated
— a higher power is desirable — we see large numbers
of much smaller cells, which in like manner discharge
their contents. But instead of ova we see immense
numbers of minute male cells, which no sooner find
themselves in the sea (a drop of water is an ocean to
them) than they put out two cilia and bep^in to swim
hurriedly, and apparently aimlessly, about. We say
apparently, for if one of these spermatozoa can succeed
in reaching and penetrating a female (egg) cell it will
have fulfilled its destiny. Then, and not till then, can
the &^% develop to form a new Wrack.

When, therefore, we add a few ova to a drop of
water containing sperm, immediately the male cells
cease their aimless wanderings and hasten to the side
of the female cell. But why ? They have no eyes to
see the beautiful roundness of her form — no senses
that we know anything about. They are only tiny bits
of protoplasm, and yet there is in them a something, a
sentiment — call it chemotaxis or what you will — we,
out for a holiday, prefer to regard it as the very germ
and essence of the tender passion. Scores, hundreds,
of the swimming cells surround the female body, which
whirls round and round on its axis, not exactly from
giddiness, but from the force of the attentions it re-
ceives. At last one of the male bodies penetrates it,
fertilization is effected, and the romance is at an end.

If a number of conceptacles of both kinds, with the
mucilage on them, are washed in a basin of water and
the contents examined daily, we may trace the first
stages in the germination of the fertilized egg cells —
and, of course, drazv them.

Several of the other brown se.uvceds present the
same features — with variations. In the .Sea Thongs,
the \\hole thong borne by the nuishroom-like frond is
beset with conceptacles. Then the number of eggs in
a bag varies in different plants. The Knotted W'rack
has only four ova in a group, the Channelled Wrack
two. These differences are now considered of sufficient
importance to warrant the establishment of two new
genera. F. nodosics, which we have already seen to
differ a good deal from the other wracks, is now
Ascophyllum nodosum; and the other is Pelvetia
canaliculata.

A fair average specimen of F. scrratus, selected by
chance, had 18 fertile branches that had already dis-
charged ova, and 16 others not fully ripe. Of the 18
a chance one had over 300 conceptacle pores on one
side, and presumably the same number on the other
fide. Now, in the course of a single season, the egg-
cases, discharged as fast as they ripen, may be put, at a
very moderate estimate indeed, at a dozen from a single
conceptacle. Each oogoniHm contains eight ova.
Total number of ova, without considering the 16 imma-
ture branches, considerably over half a million. The
extraordinary plenty of the brown seaweeds ceases to
be a matter of surprise. The sea near the shore must
sometimes teem with ova. They settle down every-
where, and at once attach themselves to the rock and
begin to develop into new plants.

Several other brown varieties will be met with which
space forbids us to describe. Two very common and
very handsome relations of the Giant Tangles, bearing
only a single ribbon, and very much smaller in size
(Laminaria saccharma and I., hulhosd) are pretty sure to
turn up. Then there are several smaller plants, much
easier to dry and mount than those we have mentioned,
though perhaps less interesting in themselves.

Here we take leave of the brown seaweeds unless
we choose to emulate the " tripper," who carries home
with him as a trophy a trailing handful of wrack — a
silent monitor, in consequence of its saltness, to warn
him of the coming storm. In the next article we shall
deal with the " Red Seaweeds," and in it we shall
have something to say about collecting and preserving.

%%%%%%

TKe Gegenschein acrvd ZodiaLcaLl
Light.

Sirs, — It would be interesting to know whether any special
observations have been made, or can be made, on the above-
named little-understood phenomena during a total eclipse of
the Sun.

Two theories have been suggested regarding the origin of
the Gegenschein. One is that it is the reflection of the Sun's
light from meteorites at a distance, which being opposite the
Sun are at •' full moon." The other is that it is the forms of
the Sun's rays reflected in our atmosphere. Now if the former
theory be correct, a total eclipse should not have any material
effect upon the appearance, but if the latter, there should be a
distinct diminution of light at the moment of eclipse.

So too with the Zodiacal Light. Some consider it as an
atmospheric phenomena, others as a solar adjunct. And
much might be done to elucidate this point if careful observa-
tions were made during the occurrence of a total eclipse.

Yours truly,

P. R. R.

204

KNOWLEDGE & SCIENTIFIC NEWS.

[August, 1905.

Acetylene Qls SLn.
Explosive.

Some interesting researches have recently been made
by M. Grehant on explosive mixtures of air and acety-
lene and corresponding mixtures of air and oil gas. The
tests were made in tubes of 50 cubic centimetres for the
acetylene and of 90 cubic centimetres for the oil gas.
The mixtures were exploded by an electrically-heated
incandescent wire. The following are the results
obtained : —

Volume Volume Perceniage

of gas. of

of gas.
50 o
333

With acetylene.

Btims with smoky flame.

Ditto.
Detonates with deposi-
tion of carbon.
Stronger detonation with-
out depcsition.
Strong detonation.

Ditto.
Very strong detonation

Ditto.

Ditto.
Strong detonation.

Ditto.

Ditto.
Less strong.

Ditto.
Feeble detonation.
Very feeble detonation.
Bums without detonation.

With Oil-gas.
Does not bum.

Ditto.
Feeble detonation.
Stronger detonation.
Strong detonation.

Ditto.
Less strong.

Ditto.
Feeble detonation.

Ditto.
Very feeble detonation.
Does not ignite.

Ditto.

These results show that the detonations obtained with
acetylene are more violent than those with oil-gas, but
that, nevertheless, the acetylene is less dangerous than
oil-gas.

COR^RESPONDENCE.

The Visibility of Planets in Daylight.

Sirs, — Some of your readers may be interested in knowing
that it is quite possible for them to see the planet Venus in
broad daylight, with the naked eye, and no apparatus of any
sort. I have for the last six months or so constantly seen
her shining high up in the heavens in the blazing light of a
South African sun at mid-day. It merely requires one to take
a rough measurement on a stick, and one evening, about sun-
set, to see how far she is from the sun, and the direction. You
cam then, next day, discover her without opera glasses or any
other help. Of course, at first it is extremely hard to find the
planet, but after a little practice the eye picks it up easily. I
have found it on a cloudless sunny day while riding along the
veld. I have also succeeded in seeing Jupiter in full sunlight
in the same way, and lately I have, owing to this practice,
managed to find Sirius and Canopus with the sun some
way above the horizon, and shining brightly. It is not only
owing to the clear atmosphere of this country, as I have
found Venus on a somewhat hazy day, certainly far less clear
than one often gets it in England. It would be interesting
also to know if any of your readers have seen the waning moon
within 40 hours or so of new moon. By careful search I have
succeeded in seeing it about that time from new moon, in mid-
day in a cloudless sky, nearly overhead. As she is so exceed-
ingly thin and close to the sun, you can imagine how hard it
is to find her with the naked eye. Those novelists or poets
who have been decried by the critics for making the crescent
moon shine overhead, will now be able to refer to my state-
ment in verification of their words.

I am, yours truly,

T. B. Hlathwayt.

Kokstad, E. Griqualand, S. Africa,
April 29, KJ05.

[As regards Venus, it is well known that this planet " Is so brilliant
that there is no real difficulty in seeing her with the naked eye in full
sunshine, or indeed at high noon." — Maundir, " Aitronomy without
a Tcltscuft," p. 147. — Ed ]

London Fog acnd Frost.

Sirs, — In a paper lately read before the Koyal Meteorologi-
cal Society, the author, Mr. F. J. Brodie, gave some useful
tabulated data of fog observed in London during twenty years,
and came to the sanguine conclusion that the great decrease
of fog in recent years points to a victory over the fiend by
smoke abatement in various ways.

Without aftirming that there is no improvement from this
cause, or questioning the obvious wisdom of efforts to do away
with smoke, I cannot but think that climatic influences are the
chief factor in the improvement observed.

If we combine Mr. Brodic's figures for autumn and winter,
andsmoothe the scries by sums of five (i.e., adding the first five.

197/ 'i. '7 'go '3 '6 "9 '9?- "y '9 O) k^

A.— Smoothed curve of Pog-days.
15.— ,, ,, l-rost-day^

then the second to the sixth, and so on), we get the curve A ;
and doing the same with the totals of frost days in winter
seasons at Greenwich, we have the curve B.

This is obviously a rough comparison, and remembering also
the uncertainty attaching to fog determinations, we should not
look for very exact correspondence in these curves ; but there
is general agreement, and, in particular, while the fog curve
shows a long general decline from about 18S9, the frost curve
does the same.

If we get up again to the 1889 level of frost, will the fog curve
fall short of Us level for that year ? That remains to be seen ;
and before giving rein to the triumphant spirit, we had better
first see, perhaps !

I am yours, &c.,

Alex. B. MacDowall.

ASTR.ONOMICAL.

By Charles P. Blti.lk, A.K.C.Sc. (L.md.), I'.R.P.S.

The Canals of Mars Photographed.

A snf)KT time back thf: important news was tclegr.iphed from
Lowell Observatory that thu much-criticised markings on
the Martian surface had been successfully photf)graphed
by Mr. Lampland, and the last circular from the observatory
not only confirms this, but contains an actual print from the
negative showing the markings.

Many attempts have been made at the Lowell Observatory
at Flagstaff, Arizona, to photograph the canals of Mars, com-
mencing with the success of Mr. Douglass in ivoi, when, by

August, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

205

using a Wallace screen, he secured a good picture of the Mare
Acidalium. Encouraging as the result was, there were no si,!,'ns
of any canal markings. The two chief difficulties were the
variation of the atmospheric tremors, and the insufficient
sensitiveness of the photographic plates. The endeavours to
get rid of these errors resulted in the ordering of a film camera
wherewith a succession of pictures could be rapidly taken
behind a Wallace screen ; and with this arrangement Mr.
Lampland has got his interesting results. A most important
item, however, has been the suitable cutting down of the
aperture of the photographic telescope to suit the particular
state of atmosphere at the time of observation.

From the many plates secured, the one taken on May 11 was
selected for the reproduction sent with the circular. Side by
side with the print is placed a photograph of a drawing by
Professor Lowell, made before the camera was placed in posi-
tion, and this serves the double purpose of showing the con-
firmation by the photograph of the objectivity of the visual
observation, and at the same time of serving as a chart to it.

The print is enlarged i'8 times from the original negative ;
and not only are the canals easily discernible, but it is evident
that they are continuous lines, and not syntheses of other mark-
ings, as has been suggested by various writers.

An additional note by Mr. Lampland states that the photo-
graphs were obtained with the 24-inch Clark refractor of
386 inches focal length. The camera carries a negative enlarg-
ing lens, the equivalent focal length of the combination being
148 ft. The camera carries a plate holder for 3^ x 4i plates,
movable perpendicularly to the optical a.xis, thus permitting a
dozen or more exposures on the planet, for the focal length
given, to be made on the same plate.

A colour screen is placed immediately in front of the plate,
separated by a small space to minimise the effect of small
particles of dust or other extraneous matter. Cramer's
isochromatic plates were used, this make being chosen on
account of the fact that one of the maxima of the curve of
sensitiveness of the plate coincides almost exactly with the
vertex of the colour curve of the large objective. The best
results have been obtained with the 24-inch stopped down to
9 or 12 inches, and the exposures were usually about eight
seconds each with the 12-inch aperture.

Spectroscopic Observations of Mercury
during Solar Eclipse.

Dr. G. Johnstone Stoney draws attention to the opportunity
which will be aflbrded during the approaching total solar
eclipse on August 30 of obtaining important observations of
the planet Mercury. At that time Mercury will be very close
to the line joining the Earth and the Sun ; its centre is 2^ 54'
South, and 2° 54' preceding the Sun, so that the distance is
only about 4° 6', and the illuminated portion of the planet's
disc will be seen as a very fine crescent. If the planet
possesses any appreciable atmosphere, the horns of this
crescent will be prolonged by the effects of atmospheric
refraction, and micrometric measurements of the degree of
such elongation would furnith material for calculating the
extent of the planetary atmosphere. For such an observation
a telescope magnifying about 200 diameters would be desir-
able. Further important and interesting determinations may
be made by treating the thin crescent as a slit, and viewing it
through a spectroscope, as then the exact constitution of the
atmosphere surrounding the planet might be ascertained.

Photographic Studies of the Planet
Mars.

Quite recently a series of successful photographs of the
planet Mars have been obtained under the direction of Pro-
fessor W. H. Pickering at the Harvard College Observatory.
In the spring of the present year the 11 -inch Draper telescope
was fitted with an enlarging lens, and it was found possible to
obtain original negatives showing the disc of the planet on a
scale of about 2"' 5 to the milUmeter.

The first photograph was obtained on March 31, and others
were secured on April i, 2, 8, 15, 16, iS, 23, 25, 27, 30. The
first photograph showed clouds at both the limb and ter-
minator, but no definite evidence of actual polar caps was
visible on the photographs until April 23, when a large light
area was clearly visible at the south pole. It did not appear
dark enough for snow, but presented more the appearance of

an extensive cloudy region. It remained visible on all the

photographs since that date, although its intensity and size
diminished somewhat. A minute light area appeared near the
north pole of the planet on April 15, but was seen only with
difficulty.

On the night of April 30, visual observations were made
with the 24-inch reflector. The southern polar cap was
clearly visible, extending far to the north in longitude 340', but
its intensity was only slight, little exceeding that of the limb in
other regions. It is considered probable that when the Mar-
tian clouds disperse snow may be found lying in their places.

Considering briefly the aspect of the planet at these times,
we notice that the heliocentric co-longitudes on April 15 and 23
were 216° and 220° respectively. These positions would cor-
respond on the earth to August 3 and 7, or to near the end of
the winter of the southern hemisphere. Snow seldom comes
earlier on Mars. It will be very interesting to observe if the
brown tint described by Lowell as characteristic of the Mare
Erythrsium will become changed to its normal colour. This
change of colour with the seasons may yet afford the best
proof of the existence of vegetation upon the planet Mars.

Ephemeris for Observations of Comet
1904 I.

This Comet will be somewhat near the Sun, and should be
looked for a little before sunrise, in the constellation Lynx,
above Cancer.

1905.

R.A.

Declination.

Relative

Brightness.

Aug. 2

8 33

s.
15

+ 43 115

0 028

'■^

43 4-7

42 58-1

0x28

42 518

42 45-7

0028

42 39-g

42 343

0'027

42 29-0

42 23-9

0 027

•,0

42 ig-i

42 14-6

0027

42 103

42 63

0 026

5t.

42 2-5

41 59'0

0-026

Sept. I

4'i

41 557

8 47

+ 41 527

0 026

,J^^^^^

CHEMICAL.

By C. A. Mitchell, B.A. (Oxon.), F.I.C.

The Flashing of Arsenic Crystals.

Arsenious oxide, the ordinary ichite arsenic of commerce,
forms two distinct modifications, differing from each other in
specific gravity, melting point, and other physical properties.
The vitreous modification is semi-transparent, but on exposure
to the air gradually becomes opaque and of a yellowish tinge
as it changes into the other vatiety. As far back as 1S35 it
was found by Rose that when the vitreous modification was
dissolved in boiling hydrochloric acid the excess of uncombined
arsenic separated out in minute crystalline octahedra from the
solution on cooling, and that on shaking the contents of the
flask in the dark a succession of brilliant flashes was emitted.
The generally accepted explanation of this very beautiful
phenomenon is that at the moment when the crystals separate
the vitreous modification is suddenly transformed into the
crystalline variety, the change being accompanied by a
liberation of energy expressed in the form of light. It has
recently been shown, however, by M. D. Gernez {Coniptes
Renclns, May, 1905), that this explanation is incorrect. He
finds that if the flask be kept absolutely still the formation of

2o6

KNOWLEDGE & SCIENTIFIC NEWS.

[August, 1905.

the crj'stals is unattended by any emission of light whatever,
but that if the flask be shaken the crystals are ruptured by
contact with the glass or each other and then produce the
flash. The property is by no means a fugitive one. and
the dry cr>-stals will yield sparks months afterwards if
rubbed with a glass rod. Mpreover, contrary to the
statements of the text books, the emission of' light is
produced as readily by cr>-stals formed from the opaque
variety of oxide as by those from the vitreous modiflcation.
The phenomenon is thus another instance of triboluinincsccnce,
the name given to the property possessed by many crvstal-
line substances of emitting light when struck or rubbed.
Herr Tchugaeff has shown that very many bodies possess the
same power. Thus, of 400 substances examined by him, 121
were found to emit light, the alkaloids, as a class, being par-
ticularly active, but only 6 out of no inorganic bodies showed
the phenomenon. The colour of the light varied with the
diff^erent substances, and its intensity could be classified
according to an arbitrary scale in which uranium nitrate was
taken as typical of the first class, tartaric acid of the second,
and ammonium oxalate of the third. The nature of the light
emitted by arsenious oxide has also been studied by M.
Guinchant, who finds that it has a continuous spectrum in the
visible part of which the green and yellow rays predominate,
though red rays are also present. The light does not affect
an electroscope, but has a strong action upon a photographic
plate, and is apparently identical in character with the light
emitted by solid bodies in a state of incandescence.

The Physiological Action of Air in
Crowded Roonns.

It is a commonly accepted belief that the unpleasant effects
produced on the human system by the air in overcrowded
rooms is due to volatile products given off bv the skin and
lungs; but experiments made by Dr. Paul of the Hrcslau
Hygienic Instituteappearto indicate that the main cause is the
retention of heat by the body. Lnder normal conditions heat
is lost by conduction, radiation, and evaporation of moisture,
as well as during respiration. The loss of heat by conduc-
tion is to a large extent prevented in crowded rooms, in
which the air is usually of a relatively high temperature,
and contains a high proportion of moisture, while the loss by
radiation is very incomplete when the body is surrounded by
others at about the same temperature. In Dr. Paul's experi-
ments it was found that headache and all the other unpleasant
symptoms could be entirely prevented by regulation of the
heat, even when the air was saturated with respiration pro-
ducts, and contained as much as 15 per cent, of carbon
dioxide ; whereas without this regulation of temperature they
appeared even when absolutely pure air was breathed. The
retention of heat could be demonstrated objectively by the
rise in temperature of the skin.

The Action of Hydrogen Peroxide on a
Photogra.phic Pla.te in the Dark.

Systematic experiments have been madu hv Dr. C. t >tsuki,
of Tokio, to determine the nature of the changes produced by
hydrogen peroxide acting upon a photographic plate in the
dark, and to test the assertion that the action of the reagent
could penetrate through a sheet of metal (see " K.sowi.edgi; &
SciENTiiic NEws,"this Vol., p. 100). It was found that gelatin,
celluloid, certain gums, and Canada balsam were permeable,
but that paraffin, fish membrane, ebonite, glass, and metals
were not. In the experiments with metals the greatest care
was taken to insure the absence of minute holes, the thin
films being examined under the microscope before and after
the exposure. The metals used were zinc, copper, tin, an
alloy of gold, silver, and platinum, brass, and aluminium in
thin films ranging in thickness from about one thousandth to
one tenth of a thousandth of an inch. Out of 47 experiments
action upon the plate was only observed three times, and in
each case minute holes were found to have been formed by
the corrosive action of the hydrogen peroxide vapour upon
the metal. The temperature h.id a considerable influence
upon the reaction between the gelatin silver bromide and the
hydrogen peroxide, lighter or darker zones in the image
(GraeU's "border effect") being produced by small varia-

tions in different parts of the plate or between the plate and
surrounding bodies. In some cases the borders were lighter
than the centre, while in others the reverse was the case. It
is not improbable that this may also account for the curious
border produced by the action of wood upon a photographic
plate in the present writer's experiment (" Knowlkdge&Sciun-
TiKic News," thisVol.,p. 120), assuming th.it hydrogen peroxide
was the active agent in this case. Professor Otsuki concludes
that the action of hydrogen peroxide upon the silver bromide
in to convert it into a lower bromide which can be reduced
leadily by the developing solution. It cannot be regarded
as due to radiation.

GEOLOGICAL.

By EiiwAKD A. Marti.n, F.G.S.

Erosion in Freshwater Bay.

The possibility of the sea breaking throui^h what remain of
the low-lying cliffs in Freshwater Bay and forming a junction
with the waters of the slug,i;ish Vare gives rise to many
interesting geological considerations. It is not a little re-
markable that a river should take its rise in such close
proximity to the sea as does the ^'are, and for an explanation
we must look back to a geological time when the sea was much
farther away to the south than it now is. Even within the
historical period great changes have taken place in connection
with the coast of the Isle of Wight, and the extent of the
island has dwindled to its present dimensions. When, too,
we look at the width of the valley of the ^are, one is apt to
wonder how such a slow-flowing stream could ever have had
the necessary force to carve a wide valley. The river is now,
however, in its old age. Probably it would long since have
been silted up, had there been a sufticient watershed to have
ensured a plentiful supply of sedimentary material. Now,
there is a chance of a new lease of life being given to it, if
the dreaded possibility happens, and the sea leaps the barrier
at Freshwater Bay, to join hands with the river itself. But
there is another possibility of a different nature. Would it be
worth while draining tifc upper reaches of the ^'are ? It
would not be a difficult matter to prevent tidal action from
having any influence beyond the town of ^'armouth ; then
much of what is almost stagnant water might be drained, and
valuable land in Freshwater Bay saved from destruction.

The Tatrns of Ticino.

In pursuance of Prof. E. J. G.irwood's studies into the
action of ice, an interesting paper has been read by him
before the Geological Society, in which he deals with the
formation of the Tarns of the Canton Ticino. Excavation by
ice-action, so far as these lakes are concerned, finds no support
in the paper in <iuestion. In some cases the ice must have
invaded the district from the outside, and from several direct-
ions at once. The lakes appear for the most part to be due
to structural peculiarities of the district, lying often in lines of
junction, or indicating lines of weakness; while at the same
time the presence of numerous springs gives rise to a belief
that solution may have formed a not unimportant part in their
formation.

GlaciaLl (?) Geology.

Sir Henry Howorth is excellent company, whether in person
or in his writings, and those who have enjoyed his humour as
a raconteur will almost feel that he is playing an enormous joke
at the expense of the geological world in launching his thou-
sand-page work on " Ice and Water." Sir Henry is following
up with his usual courage his contentions in regard to the
generally-accepted theories of ice-action and water-action, and
those who have read and enjoyed "The Glacial Nightmare"
and "The Mammoth and the Flood" will be prepared for this
further exposition of his views. Almost as one crying alone in
the wildern<'ss, his works an- full of ixcellcnl reading, and
crowded with data, brought together with infinite patience,
and if one is apt to develop too much into an extremist in any
particular school of geology, one finds an agreeable corrective
here.

August, 1905.

KNOWLEDGE & SCIENTIFIC NEWS.

207

Uintacrinus in the Croydon Chalk.

Dr. G. J. Hinde has found .ivery close resemblance to some
of the higher zDuesof the chalk of the coast near Margate in the
chalk of'the tract between Russell Hill and Beddington, in
Surrey. Hitherto the chalk hereabouts had been thought to
belong to the zone of Micyaster cor-aiit^uiiium, although when
last year the third volume of the " Cretaceous Rocks of Great
Britain" was published by the Geological Survey, it was
anticipated that the zone of Maisii/^ilcs was present. Doubts
have now been set at rest by the discovery by Dr. Hinde of
some test-plates of free-swimming crinoid Mai-supitcs, with
Echinocoiys scutatiis ; and at the same time he discovered
some smaller inconspicuous test-plates, which, on close ex-
amination, were found to belong to the unstalked free-
swimming crinoid known now as Uintacrinus. These show the
existence", near the place where the chalk disappears beneath
the tertiaries, to reappear on the north of London, of the
lower portion of the Marsupitcs-zone, called by Dr. Rowe the
" Band of Uintacrinus." The fossils found by Dr. Rowe in
this band in coast-sections near Margate agree almost identi-
cally with those found by Dr. Hinde near Beddington.

O R.NITHOLOGICAL.

By W. P. Pycraft, A.L.S., F.Z.S., M.B.O.U., &c.
The Scent of Sitting Birds.

Mr. Tegetmeier, at the last meeting of the British Ornitho-
logists' Club, made some interesting observations on the scent-
less nature of birds when sitting on their eggs. He contended
that the physiological explanation of this was well known, and
that the "vicarious secretions" causing the scent were re-
tained within the body in sitting birds, and passed into the
cloaca, to be eventually voided with the faeces. The odour of
the f;eces dropped by a silting bird was, he said, totally
different from that passed at other times, and their particularly
offensive smell was caused by these secretions.

We venture to think that this explanation will not stand the
test of investigation. Birds are unique in the glandless nature
of their skin, even sweat glands being absent. Whatever smell
escapes is probably exuded by the feet ; hence the care taken
by many birds to fly straight off from the nest, and so prevent
the tell-tale traces, which would otherwise be left, of the
whereabouts of their eggs. The unusual offensiveness of the
faeces may be explained by their long retention in the cloaca.

The Eggs of the Knot.

Dr. Bianchi, of the St. Petersburg Museum, brought with
him, on his recent visit to London, a collection of twelve eggs
of the Knot (Tringa canittus), and a few nestlings, and these
he exhibited at the last meeting of the British Ornithologists'
Club.

The nestlings of this bird were discovered by Colonel
Fielden when in the Arctic expedition of 1876; but the eggs
remained unknown till discovered by the late Dr. Walters on
an expedition to the Taimyr Peninsula in igoi. To allay all
doubt as to the identity of these eggs the parent birds were
also taken. The eggs are remarkable for the great variability
which they show in size, form, and colour. The ground-colour
ranged from " pale clay " to pale yellowish white, and pale
green. The markings took the form of dirty-brown and violet-
grey spots, tending to cluster at the blunt end of the egg, and
varying much in size.

Dr. Walters was the medical attendant and ornithologist of
the expedition, and died before it returned, at Kotelny Island,
December 21, 1902.

Nesting of the Scoter in Ireland.

The Field, July 15, contains a most interesting account
by Major Trevelyan of his discovery of the breeding of the
Common Scoter (CEdcmia nigra) " on one of the loughs in
Ireland " during this summer. He had the good fortune to
discover the female sitting on a nest of eight eggs in June last.
This was placed under a small bush on an island. On
July I, he found her with five young ones swimming about in
the lough. Tufted ducks were breeding here in some numbers.

and in several casoi it would appear that more than one
female was laying in the same nest, since as many as twenty-
one eggs were found in one case and nineteen in another !
Two other nests contained sixteen and eighteen eggs respec-
tively. Gulls seem to levy a heavy toll on the young of these
birds, as well as on the eggs.

The exact locality of this new breeding-ground is very wisely
withheld.

Waxwings in Berkshire.

In the Bulletin of the last meeting of the British Ornitho-
logists' Club, Major F. W. Proctor records the occurrence of
a pair of Waxwings (Ampclis garrnliis) at Maidenhead Thicket
on April II. They were, we learn, unmolested, but whether
they remained to breed has so far not been ascertained.

Marsh-Warbler Nesting in East Kent.

Mr. CoUingwood Ingram at the meeting above referred to
exhibited an egg of the Marsh- Warbler (Aerouphalus p3,liislris)
taken from a nest of five. The remaining four eggs were left
and hatched out. This is believed to be the first authentic
instance of the breeding of this species in Kent. The nest
was placed in on the shoots of a young ash-tree about three
feet from the ground. It was composed of dried grass-stalks
and lined with horse-hair and cocoa-nut fibre, the latter
procured from a neighbouring hop-garden.

The Western Bla.ck-Eared Cha^t at Hove.

An example of the Black-eared Chat (S-ixicola albicoUis
cafi-riiiLr) was killed at Hove on May 22, 1905. This is the
second recorded instance of this bird in Sussex; the first
example having been killed three years ago. Both cases were
reported to the British Ornithologists' Union by Mr. R.
B'.itterfield, who saw each bird in the flesh.

PHYSICAL.

By Alfred W. Porter, B.Sc.
A Scientific Essentia.1.

And above everything the scientist must foresee. Carlyle
wrote somewhere to this effect : " The fact alone matters ;
fuhn Sansterrc passed this place; there is a reality for which
I would give all the theories of the world ! " Carlyle was a
compatriot of Bacon, but Bacon would not have said that.
That is the language of the historian. The physicist would
say rather : John Sansterre passed this way ! That is
nothing to me, since he will not pass this way again.

Poincarc, La Science ct Vhypothese.

The Alpha Stream.

Professor Rutherford is making an extended investigation
into the properties of the Alpha stream of particles emitted in
many of the stages of disintegration of radium. .A preliminary
account appears in the Philosophical Magazine for July. The
main object of the experiments is to obtain a more accurate
measure of the mass of each of these particles, and thence to
decide whether or not they are identical with helium. This
better value has not yet been obtained, but many facts of
importance have turned up in the course of the preliminary
observations.

Previous measurements have been made on the particles
shot out from radium. But it is now known that radium in a
state of radio-active equilibrium is a very complex substance ;
and that the particles shot out at different stages do not leave
with the same velocity. The improvement now introduced is
to use one of the disintegration products alone, viz.. Radium
C. Radium A (the product of the disintegration of the ema-
nation) is deposited on a highly negatively charged wire.
This quickly breaks up successively into Radium B and C,
and the Alpha particles then shot out are taken as
arising from C because B does not emit any. This wire is
then placed behind a slit, and the stream that passes the slit
falls on a photographic plate, slit and plate being placed a few
centimetres apart. The whole is placed in a transverse mag-
netic field in a vacuum, and the field reversed every ten
minutes for about an hour. On development the plate shows

2o8

KNOWLEDGE & SCIENTIFIC NEWS.

[August, 1905.

two narrow bands, at greatest 47 mms. apart, and from this
measurement the curvature of the stream due to the field was
determined. From this the value of mass X by velocity -=-
charge of each particle can be calculated. The values ob-
tained are much more definite than previous ones. To com-
plete the calculation of the mass, it is necessary to deflect the
stream by an electrical field as well. This has not yet been
done, owing to the difficulty of quickly obtaining a sufficiently
high vacuum.

If thin aluminium sheets are interposed the velocity of the
stream is reduced : and experiment shows that the photo-
graphic action ceases when the velocity is still 64 per cent, of
its initial value — i.e., when the velocity is about one-twentieth
that of light. The ionising and phosphorescent action also
cease at this velocity. This is a surprising result, for the
particle still possesses nearly 40 per cent, of its initial energy
at this stage.

The similarity in respect to the three phenomena can be
most simply explained by supposing that photographic action
and phosphorence are essentially due to ionisation.

It is most interesting to observe that the actual velocity of
emission is on the average only about 30 per cent, greater than
this critical velocity. The .\lpha stream would not have been
detected if its velocity had been much less than it is. Professor
Rutherford points out that disintegration may be taking place
in other substances and be practically undetectable, because
this lower limit of ionising velocity is not attained by the par-
ticles emitted. This remark may also apply to Radium B,
which is a so-called raykss product ; and we further suggest
that a similar remark may apply also to the Beta particles,
and^that such slow velocity negative particles may therefore
be present in each 0/ the stages of disintegration. This supposi-
tion would remove the difficulty which some feel in conceiving
of the production of a positive particle without a negative one
being simultaneously generated.

ZOOLOGICAL.

By R. Lydekker.

The Late Dr. W. T. Blanford.

Zoologists and geologists throughout the world will hear
with unfeigned regret of the death of Dr. William Thomas
Blanford, C.I.E., F.R.S., which took place at his residence in
Campden Hill, London, on June 23. after a brief illness, in
his 73rd year. Dr. Blanford was on the staff of the Geological
Survey of India from 1855 till 1S82, retiring with the rank of
Senior Deputy Superintendent. He was a gold medallist of
the Royal Society and aWollaston Medallist of the Geological
Society, and had been President of the latter body as well as
of the Asiatic Society of Bengal. During his Indian service
he was attached as naturalist to the Abyssinian Expedition
under Lord Napier, and later to the Persian Boundary Com-
mission under Sir F. Goldsmid. Of late years he had devoted
himself largely to the study of the geographical distribution
of animals and of the changes in the configuration of the
earth's surface which have had so much to do with the same.
Among his important works may be mentioned the " ^Zoology
and Geology of Abyssinia," the " iJoology and Geology of
Eastern Persia," the " Manual of the Geology of India,"
written in collaboration with the late Mr. H. B. Medlicott ;
the Mammalia and the Geology of the Second Varkand
Expedition, and the volume on Mammals and two of those
on Birds in the "Fauna of British India," of which series
be was the editor.

The Origin of Salamanders.

At the conclusion of an elaborate memoir on the develop-
ment of the vascular and respiratory systems of the Australian
lung-fish (Ceratodut fosterii, published by the New York
Academy (Mem. II., part 4), the author, Mr. W. E. Kellicott,
remarks that the main object of his investigation was to obtain
evidence with regard to the relationship of the lung-fishes,
or Dipnoi, to other groups. " It is impossible to believe," he
observes, " that the Amphibian resemblances seen in Ccratodus
in the development of the vascular, respiratory, and urino-
genital systems, as well as throughout the earlier processes of

development, are in the nature of parallelisms. In the light
of their embryology it is impossible to believe that the Dipnoi
and the Amphibia are not closely related, and that they have
not travelled for a time along the same path at some period
during their history." If this view is to be accepted, we must
apparently regard the early lung-fishes as the direct ancestors
of the extinct primeval salamanders, or labyrinthodonts.
A further inference would seem to be that the gills of modern
salamanders (which in certain kinds are retained throu,t;hout
life) are directly inherited from fishes, and not, as h.is been
suggested by some, a new and independent development.

A New Group of Extinct FLeptiles.

In a recent issue of the Memoirs of the California Academy
of Sciences (Vol V., No. i) Mr. J. C. Mcrriam describes a
group of extinct marine reptiles from theTriassic (L'pper New
Ked Sandstone) deposits of California, which he regards as re-
presenting a new order, the Thalattosauria, typified by the
genus ThaUittosanrus. In many respects these reptiles re-
sembled the ichthyosaurs, or fish-lizards, having the eye simi-
larly furnished with a ring of bony plates. They are, however,
broadly distinguished by the upper temporal region of the
skull, which has an upper and a lower bony arch, and likewise
by the character of the dentition, which takes the form of
flattened, crushing teeth, some of which are situated on the
palatine and vomerine bones. From these and other features
the thalattosaurians appear to be most nearly allied to the
rhynchocephalians, as represented at the present day by the
New Zealand tuatera (S/'lienodoii), to which they appear to
present the same kind of relationship as is borne by the extinct
sea-serpents (Pythonomorpha) to the lizards. If this be so the
Thalattosauria might perhaps be best regarded as a sub-order
of Rhynchocephalia. He this as it may, the special interest
attaching to the group is the evidence it alTords of the inde-
pendent adaptation of yet another type of reptile to the exigen-
cies of a marine existence, and this, too, at an early period of
the earth's history.

The Origin of Mammals.

In a paper communicated to the March issue of the Zoolo-
gischer Anzeiger, Dr. Sixta, of Bohemia, discussed the evidence
at present available with regard to the ancestry of mammals
and fully endorses the view of those who hold that the group
is directly descended from reptiles, and has no near kinship
with amphibians. As regards the earlier stages of develop-
ment, Dr. Sixta points out that the Australian duck-bill, or
platypus, on the one hand and reptiles on the other are inti-
mately related ; the resemblance, in all stages of develop-
ment, being most significant when the duck-bill is compared
with the chclenian group (turtles and tortoises). The chief
features in this resemblance were, according to Dr. Sixta,
noticed independently by himself and by Dr. Mill, of Sydney,
as the result of different modes of investigation, anil may
therefore be regarded as well-founded. That reptiles were
the direct ancesters of mammals is now, in the author's
opinion, an ascertained fact.

Papers Rea.d.

At the meeting of the Zoological Sotiety, on May if). Mr. O.
Thomas described a new South African golden mole. Mr.
F. E. Beddard contributed a paper on the cranial arterial
system of birds and reptiles. Sir H. H. Johnston criticised Mr.
Rothschild's views with regard to the classification of man-like
apes, while Mr. K. Andersen discussed certain kinds of horse-
shoe bats. On behalf of Dr. E. Bergroth, a communication
was read on the siridulating organs of certain hemiplerous
insects. Dr. P. C. Mitchell discussed the anatomy of the
Limicolina birds, and Mr. R. I. Pocock redescribcd the
Hainan gibbon. .\\. the final meeting of the session on June 6,
Col. C. Delme-Radellffe gave an illustrated account of the
natural history of West Uganda. Mr. M.Jacoby described new
forms of (lidionychis. Dr. Mitchell discussed the mammalian
intestinal tract. Dr. H.Gadowreada paperon the distribution of
Mexican amphibians and reptiles. Mr. G. A. Boulenger descri-
bed new reptiles collected by Dr. Gadow, and also new reptiles
and amphibians from South Africa. Mr. Beddard referred to
features in the anatomy of certain lizards. Mr. R. Assheton
reported on the development of the spiny mouse. The Rev.
S. Gorham described new South African beetles, and Baron
F. Nopcsa discussed the position of one of the bones in the
skeleton of Diplodocus.

August, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

2og

REVIEWS OF BOOKS.

The New Knowledge, by Robert Kennedy Duncan (Hodder
and Stoughton ; price 6s. net).— Let nobody be discouraged by
the title of " The New Knowledge " which Robert Kennedy
Duncan has given to a volume which sets out, in language
which is plain-spoken and easily understood, a good many of
the new views in chemistry and physics that the lately
imagined anatomy of the atom has created. Let them also,
while reading his preface, forgive him for the expression that
" in science when a new Alaska is discovered there is a rush
of tenderfeet to the district "—for the sake of the germ of
truth it contains. What Professor Duncan means is that when
an attractive theory is started, such as that the line between
force and matter is indiscoverable and perhaps does not exist,
there are hosts of raw speculators, who, having been at no
pains to arrive at this theory by the slow process of ascer-
tained facts, make up for their lack of knowledge or industry
by windy forecasts of what may possibly turn out to be true.
Such, for example, are the immature students who announce
that in radium's activity lie the germs of life. Professor Dun-
can's method is not this. He wishes clearly to set out with-
out speculation, without surmise, and as simply as possible,
the new conceptions of matter, and to show how they are re-
lated to one another, and how they are mutually interdepen-
dent. He considers, therefore, the later ideas concerning
the implied meanings of the terms Matter, Energy, and
Ether ; and the consequent importance of the symbols, atom
and molecule. Thence he shows how the Periodic Law,
governing the structure of the elements which atoms build,
took a further step along the road of theory ; and, after that,
how the theory of the travelling corpuscle, the " ion " of a gas,
arose. The relation of the corpuscle, and the force with
which the corpuscle is charged, lead up to the confirmation by
solids of the laws suspected as existing in gases. Finally, the
re-determination of these facts by the observed phenomena of
radio-activity is considered, and the reasons for formulating
an electric theory of matter, and for regarding the atom as a
planetary system of ions or forces, are shown. Professor
Dimcan has brought together a number of modern theories ;
he has considered them not critically perhaps, but logically ;
and he has shown how they are related to one another. His
volume is one which can confidently be recommended to that
vast army of inquirers who, not themselves being scientific
students of physics, are yet possessed of trained intelligence,
and who want a good book on the whole subject.

K Manual o( Quaternions, by Charles Jasper Joly, D.Sc,
F.R.S. (Macmillan ; price los.). — Professor Joly modestly
describes his volume on Quaternions as introductory to the
works of Hamilton, the great expositor of a new mathematical
method ; but it is a great deal more than that. It is a digest
of the works of Hamilton, of Tait, and of other mathematical
essayists in this subject ; it embraces many results which have
appeared in the publications of learned societies, and many
others which are new ; and so is to be regarded rather as a
definition of the uses, the applicability, and the possibilities of
Quaternions in mathematical usage as at present understood.
This view, however, of Professor Jcly's work is not exhaustive,
for it does more than gather the theories and expositions of
Quaternions mder one roof; it is, if not a royal road, then, at
any rate, a very carefully constructed road along which to
approach them, and one which no other writer has attempted
to provide. The works of Hamilton do not aim at teaching
the uses of Quaternions ; they rather exhibit the implications,
the consequences, and the hypotheses of the symbols ; the
student may be imagined as panting after Hamilton up
mathematical heights in order to attain comprehension and
power. Professor Joly's method is not the same. He ex-
hibits the properties of the Quaternion early in his treatise ;
he takes the student blindfolded along one defile, and he cuts
steps in which he may place his feet. The readers of this
notice must pardon a slight exuberance of metaphor ; our
final intention is to say that Professor Joly has written a
book on Quaternions which will be invaluable to the
student. It exhibits the practical uses of the Quaternion
in working out mathematical problems ; its own methods
are developed with admirablv patient clearness; and it is
introductory to the works of Hamilton in the sense that study

of it will open up fields of mathematical inquiry which

hitherto have been worked by the few rather than by the
many.

The Evolution of the World and of Man, by George E. Boxall
(London: Fisher Unwin, 1905). — This may very justly be
called a book of nonsense. It has fallen to our lot to have to
read many stupid or indifferent books on the evolution theory,
but a more pitiful muddle of fact and fiction than is to be
found within the two covers of this volume has, we venture to
say, never before been offered to a long-suffering public.

The author assures us that this work was undertaken " not
so much for the advancement of science ... as for the
benefit of the man in the street— that is to say, the common
people " ! We shall be surprised if " the man in the street "
does not show discrimination enough to leave this pretentious
guide to knowledge severely alone, though, as a rule, we must
sorrowfully admit " the common people " are but too ready to
read stuff of this kind. In like manner they run after patent
medicines, patent foods, faith healers, and other quackery.

By way of a sample of what is offered for the consumption
of "the common people," we give one or two illustrations.
Thus, " For the production of young " we are told " the female
supplies the protoplasmic base in the shape of a seed or an
egg, which is fertilized by the male introducing into it matter
containing the necessary life germs ! ! " Again, " But the
change of form from one order to another — as from univalve
crustace;e to bivalve, from these to the articulated shell-fish,
or from these to the vertebrates — marks an era in evolution " ! ! !
Man we are told has been evolved from a creature closely
resembling the marsupial Koala, which, for want of a better
name, he calls " the Menschensvorganger, or Menschens-
vorfahrer, the progenitor, ancestor, or precursor of man " ! !
Shades of Darwin and Huxley, what are we coming to ?

But why go on ? We have surely said enough to show that
no words of condemnation can be too strong for this jumble of
silliness. W.P.P.

Some Elements of the Universe Hitherto Unexplained, part I.,
by A. Balding (King, Sell, and Olding; price is. 6d.).— Pre-
sumably this book would not have been written had the author
fully grasped the significance of "relative motion," "instan-
taneous eclipse," and other well-known ideas. Before reaching
Chapter I. we find a list of definitions, some of which might
have emanated from a Junior Science Form, e.g., " Quadrature
— A quarter of the heavens or a point intermediate between
directly opposite parts of the sky." This is discouraging and
tends to render us more critical. Some of the statements are
not so clear as the above sample. The author proceeds to
account for the conservation of energy in the solar system by
the motion of that system in space, and insists on dealing with
" real paths." This is tantamount to finding all motor-cars
guilty of " contravening the Act " by travelling (many of them
backwards, sideways, or even vertically) at a speed never less
than 20,000 miles an hour. The motion of Halley's comet and
of the earth are treated in this unnecessarily complicated
manner, and then the author falls foul of the accepted explana-
tion of the Equation of Time, said to be due partly to the
eccentricity and partly to the obliquity of the earth's orbit.
The first part is confessedly inadequate by itself; the second,
savs our author, lioes not exist. How would he deal with an
obliquity of 90° ? Again, though it is obvious the solar day
must be longer when the earth is moving faster in its orbit, he
professes to find this an enormous difficulty only to be ex-
plained from his new point of view. His simple derivation of
a new value, 234", for the longitude of the solar apex, from the
radiants of meteors, is unfortunately quite unsound, as the
meteors are not independent of the solar system, even if we
grant the accuracy of a mysterious table of " true radiants."

Our Stellar Universe : A Road Book to the Stars, by T. E.

Heath (King, Sell, and Olding, Ltd., 1905 ; pp.74; 5s. net). — The
authnr has introduced a most interesting scheme of presenting
the members of the stellar universe to the popular as well as
the general scientific reader. The general impression after
reading many astronomical treatises is that the stars are so
far removed that the only possible conception of them is as if
they were lying on the surface of a sphere, all at practically the
same distance. The present book is to show that, with the
most recent and authentic values of stellar parallax, it is con-
ceivable to picture many members of the stellar universe as
situated at various distances from the Sun.^Not only this, but

KNOWLEDGE & SCIENTIFIC NEWS.

[Arr.rsT, 1905.

it may be that a more correct idea of the relative importance
of the various bodies can be thus ol)tained. The unit on which
all the measurements are made is the light-year, and there is
a fortunate coincidence in the fact that if the dislaiue uhicli
light travels in one year be represented hy one mile, thin the distance
of the earth from the Sun will be represented by one inch on the same
scale. Based on this idea, a series of maps are presented,
showing the positions of the members of our solar system, all
stars within the distance of 60 light-years, and those within
430 light-years. These are compared with known terrestrial
distances in order to fix ideas. Next an endeavour is made to
present a stereoscopic chart of the stars, the size of the relative
images being made proportional to their sun-power. The dis-
tance between the two images is taken as 107 light-years, and
the distances plotted according to the best determined parallaxes.
The stereograms given are very interesting, but, beyond giving
a concrete illustration of the effect of parallax, cannot be con-
sidered as showing the actual distribution of stars in space.
An appendix contains useful lists of stellar magnitudes, spectral
types, and parallax values.

Our Stellar Universe, by T. E. Heath (King, Sell, and
Olding, Ltd., 1905; 3s. net). — This little volume contains six
stereograms of the sun and surrounding stars, and is intended
as a companion to the author's larger work above mentioned.
An index of all the objects shown on each chart is included,
with the individual magnitudes, comparative sun-power, and
spectral type.

The Hand Camera and What to do With It, by W. L. F.
Wastell and K. Child Bayley (Iliffe and Sons; price is. net). —
The photographic possibilities, and the principles that underlie
them, in the use of hand cameras is a very large subject. But
practical work of the kind that has come to be known as
" snap-shotting" is so simple that those who indulge in it are
apt to underrate the value of a general knowledge of the facts
that their results depend on. AH such, as well as beginners in
the art, will reap considerable advantage without much intel-
lectual effort by reading this volume. The authors deal with
the purchase of a camera, the several types of cameras and
their various parts, the manner of their use, the development
of the negatives, and the preparation of prints and enlarge-
ments from them. The information given is practical and
reliable and well selected. The volume takes the place of one
written a considerable time since by Mr. Welford, and perhaps
this accounts for the inclusion of the " uniform system " of
marking lens diaphragms, which was never widely adopted,
and was officially withdrawn many years ago by the Royal
Photographic Society, who were responsible for its intro-
duction. Half-a-dozen good reproductions of hand-camera
pictures are given, four of which are of architectural subjects,
and serve to show the use of the method in a sphere that too
many regard as altogether outside its scope.

The Nature o( Explosions in Gases. H. B. Dixon, F.R.S.
(Henry Frowde ; i5. 3d. net). — This is the tenth Boyle lecture,
delivered before the Oxford University Junior Scientific Club,
and deals in particular with the mode in which flame is propa-
gated in explosions and the nature of the chemical reactions
occurring. Reference is made to the fact that it was while
repeating Bunsen's work that he discovered that a dried mix-
ture of carbonic oxide and oxygen would not explode under
the action of a spark which readily kindled the moist mixture.
The main part of this lecture is concerned, however, with the
rate of explosion. Berthelot showed this rapidly increases
from its point of origin until it reaches a maximum which
remains constant however long the column of gases may be.
Mr. Dixon considers that the wave must be propagated not
only by the burnt but equally by the unburnt molecules (with
which the former exchange velocities), and that therefore half
the unburnt molecules are heated by the collision before they
are burnt. He finds an extraordinary close agreement
between the rate calculated from this point of view and the
actually observed rates. Some photographs of compression
waves through heated gases are reproduced and discussed.

We have received Electricity No. 21, Vol. XIX; and The
Indian Electrical and Mechanical Textile News, No. 8, Vol. II.
(Bombay), containing amongst articles of interest on electrical
and other topics a capital portrait of Sir Joseph Wilson Swan,
F.R.S.

Suggestions Towards a Theor>' of Electricity Based on the
Bubble Atom. John'Fraser. — This is a reprint from the Procued-
ings of the Royal Society of Edinburgh. It is very diflicult to
appraise the theory which is here presented, because the author
is not very clear in the way that he brings it forward. It is
obviously highly original, although it bears certain resem-
blances to Osborne Reynolds' theory of matter. On both
theories matter is supposed to be represented by gaps in the
ether. On Mr. Eraser's theory the ether is prevented Iromfalling
into these gaps by the rapid motion of the particles forming
the surface of the gap. We cannot follow the author into his
applications of his theory to the elucidation of the electrical
properties of bodies. Hut we must remind him that a tremen-
dous quantity of experimental facts are now known, and any
theory which hopes for a long life must be capable not only of
explaining these but also of keeping step with the rapid pro-
gress of discovery. If Mr. Frascr will find some friend more
skilled in the art of advocacy than he seems himself to be, it
is possible that the numerical correspondences which he dis-
plays in a table at the end may be shown to have a great value
in guiding theoretical physicists to a correct view of the con-
stitution of matter.

Practical Gum-Bichromate, by J. Cruwys Richards (Iliffe
and Sons; price 2s. 6d. net). — This process, which has lately
been in great favour with those who like to alter their photo-
graphic results to suit their taste, is here described by a
practised hand. The directions are so plain and straight-
forward that anyone may follow them ; but, of course, the
worker's success, from a pictorial point of view, must depend
upon his skill and artistic knowledge, for this alone can guide
him in the " local treatment," and the putting in of '• bright
specks" by means of " the point of a penknife, or a dry brush,
or anything else that experience may dictate." The author
has given his own methods of work and his own preferences ;
but he has added the formulae for coating the paper as used by
several other well-known and successful workers of the process.
The illustrations are excellent guides to the appearance of
prints at various stages of their production, especially in the
multiple printing methods.

Unbeaten Tracks in Japan, by Isabella L. Bird (Mrs. Bishop)
(London: John Murray, 1905 [Popular Edition]; 2s. 6d.). — In
issuing a cheaper and popular edition of this charming volume
we venture to think some intimation should have been given
to the effect that this book is concerned with Japan as it was
some sevenandtwenty years ago. It would also have added
much to the convenience of the reader if the full dates of the
several letters, which make up the chapters of this work, had
been added. Only here and there do we get anything nearer
than " May 30 " or " August 24." The first letter appears to
have been written on May 21, 1878, the last on December 18
of the same year.

We suspect that the horrible neglect of sanitation so vividly
described by Mrs. Bishop is to-day, for the most part, a thing
of the past, even in the out-ofthe-way regions described.
Certainly we hope that the unspeakable cruelty which appears
to have been practised on horses has long since ceased.

This book is too well known to need a Ipng description. In
its new and most attractive form it should gain a large number
of fresh readers.

Wasps Social and Solitary, by George W. Pcckham and
Elizabeth G. Pcckham (A. Constable and Co.; price 6s.
net). — It is difficult for the casual reader to ascertain the
exact object of this book, and whether it is intended for
the nursery, schoolroom, or as a scientific treatise. The
plain and childlike language and the simple and, we may
say, unscientific methods of observation described would
lead one to suppose its object was to instil into the juvenile
mind an interest in natural hii^tory. ^'et there is something
more than this in the book. The careful observations noted
and recorded have their value to the student, and the habits
of some species of wasps are well worth noting and recording.
The detailed account, for instance, of an Ammophila making
its nest in the ground, filling up the hole, and then pounding in
the grains of sand by means of a small pebble held in its
mandibles, is certainly most interesting. The illustrations
are by James H. Emerlon, whose age is not given, but we
should doubt whether his talent', when he grows up, would
qualify him for Academic honours.

August, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

211

Photography.

Pure arvd Applied.

By Chapman Jones, F.I.C, F.C.S., &c.

The Action of Hydrogen Peroxide on Photographic
Plates.— Dr. Chiri Otsuki has made a communication
(Jour. Soc. Chem. Ind., 1905, p. 575) on this subject,
in which he confirms many of the results obtained by
Dr. Russell some years ago. What seems to me the
most important detail in this communication, though
the author appears to regard it as of very little import-
ance indeed, is the statement that a plate that had been
acted on by hydrogen peroxide and that would have
given an image by development, partly lost the possi-
bility of development by " laying the photographic plate
for eleven minutes in water," and that " after leaving
it one hour in water after the exposure no picture of
the hole was obtained." It seems that Dr. Otsuki's
onlv conclusion from this is that the developable possi-
bility is due to something (hydrogen peroxide) con-
densed on it, and that may be washed off or out of it.
But developable silver bromide cannot be watered back
into the undevelopable variety. If the peroxide can be
washed away and leave the plate unaffected, then it
does not produce the developable condition at all, but
merely co-operates with the developer, in the absence
of light, to reduce the silver bromide to the metallic
state. Or it may be that the developable condition pro-
duced by a form of radiant energy emanating from the
peroxide is destroyed by the soaking in a weak solution
of the peroxide, though this latter explanation appears
hardly tenable in face of the fact that Dr. Luppo-
Cramer in his experiments immersed the plates in solu-
tions of hydrogen peroxide. In any case this possi-
bility of washing away the peroxide, and with it any
effect that it may have produced, is of the greatest
importance, if it can be confirmed. Theories ought to
count for very little while facts are in doubt, therefore
I do not think it worth while to refer to those put for-
ward by Dr. Otsuki, especially as they appear to me
to be founded on many false assumptions. I still think
that some of the results obtained by Dr. Russell and
those who have followed him cannot be explained on
the simple vaporization theory, and I see no reason to
qualify the remarks I made on these experiments seven
years ago, and in the last January and February num-
bers of this journal.

The Spectrum as a Photographic Test. — It is difficult
for the person who has not been scientifically trained to
appreciate the statement that the spectrum is, and must
be, the only final test object in all experiments concern-
ing colour sensitiveness, colour reproduction, and the
like. It seems to be a common idea that scientific
instruments can be used and the results they give
interpreted by anyone who can use the instruments in
the sense in which one uses a tourist's telescope. Of
course, this is a grave error, but it accounts in large
measure for the ideas held by many that spectrum tests
are deceptive, that as spectra " do not grow on trees "
they are not suitable objects to work with in seeking
for methods of photographing Nature, and that a
process may be right spectroscopically but not right
when tested with pigment colours. The expression
" the spectrum," that one is forced by custom to em-
ploy, is deceptive, for it often conveys the impression
that there is a spe:trum or some particular spectrum

that is the standard spectrum, and so hides from the
merely practical mind the fact that spectra are as
numerous as lights — indeed, may be far more numer-
ous, and that in dealing with a spectrum one has the
given light simplified by being separated into its com-
ponent parts. But this very simplification when
unwisely done may be a source of confusion and error,
as if one in seeking for the beauties of language in a
piece of writing were to dwell unduely upon the etymo-
logy and the spelling of the words.

A spectroscope is really a very dangerous guide in
the hands of those who do not thoroughly understand
it; it is too often like a micrometer in the hands of a
tailor, unnecessary, troublesome, and misleading.
Those who have not made a special study of its use
should have but little to do with it; they should rely
upon a judicious selection of pigments or coloured
glasses. With these a great deal can be done; per-
haps, indeed, all that is necessary for practical pur-
poses. But at the same time, final and inclusive work
can be done only spectroscopically, and only by one
who is really expert in the use of the instrument for the
particular purpose required.

For ordinary photographic purposes in connection
with colour, I think that the chief difficulties peculiar
to this kind of work result from the unequal dispersion
given by prisms, the employment of a too small or too
large dispersion, and the giving of unwise exposures.
It is generally desirable to give a series of exposures in
geometrical ratio, and it may be necessary to reduce
with a coloured screen the light that is most active.
Of course, there are many other experimental diffi-
culties which are common to all spectroscopic work,
and others common to all photographic work.

Oxidation of Sodium Sulphite Solutions. — The oxida-
tion of sodium sulphite by exposure to the air takes
place far less readily than is often supposed. The
effiorescence on the crystals has been taken by many
chemists as evidence of the presence of sodium
sulphate, whereas it is due merely to the loss of water
of crystallization. Solutions of the salt are also stable
if preserved with common care. Messrs. Lumiere and
Seyewetz have recently observed that they are even
less liable to oxidation if a small quantity of a developer
is added, and they give the following list, placing the
substances in order of their effectiveness. Hvdro-
quinone is the best; then follow, paraamidophenol (the
active agent of " rodinal "), glycin, paraphenylene-
diamine, catechol, metol, " metoquinone," amidol,
adurol, edinol, and eikonogen. The addition of alkalies
or their substitutes, such as acetone or formaldehyde,
diminishes the preservative action. Hence the idea that
a one-solution developer, especially if made with hydro-
quinone and also in the case of " rodinal," is peculiarly
free from liability to spoil by exposure, seems to be
founded on fact.

Competition. — The Thornton-Pickard Manufacturing
Co., of Altrincham, are offering several series of cash
prizes for photographs taken under conditions that will
be sent on application. The entries must be received
before October i.

The Potentia Organization.

An international organization is being formed by a number of
influential representative men to establish amongst nations a mutual
relationship and co-operation for the diilusion of accurate informa-
tion on events effecting the peace of the world. Sir Vincent
Caillard, Professor G. H. Darwin, and Sir Michael Foster are the
English representatives.

KNOWLEDGE & SCIENTIFIC NEWS.

[August, 1905.

C'jndlUtcd ilj F. SlllLLINGTON SCALES, I'.R.M.S.

R^oyal Microscopica.1 Society.

June 21st, at 20, Hanover Square, G. C. Karop, Esq.,
M.R.C.S., Vice-President, in the chair. — Three old
microscopes were presented to the Society's collection
by Mr. C. L. Curties. A noteworthy donation to the
Library was the concluding: part of Dr. Braithwaite's
" British Moss Flora," the publication of which ex-
tended over 25 years. Dr. Lazarus-Barlow exhibited
and described a new form of warm stage, devised by
him, which could be heated by oil or gas. The regula-
tion depended upon the expansion and contraction of a
fixed volume of air, acting through a manometer upon
a delicately-balanced lever, at one end of which a silver
rod was carried in a horizontal position, the flame being
applied to one end of the silver rod, while the other
end, which was bent downwards, dipped into a parafBn
bath attached to the side of the stage. .As the tempera-
ture of the stage increased, the contained air expanded,
and acting on the manometer caused the lever to raise
the silver rod and so to practically withdraw the bent
portion from the paraffin bath. Mr. C. R. C. Lyster
also exhibited an improved form of warm stage, heated
by electricity. Such warm stages are generally heated
by resistance coils, but the variations in the intensity
of the ordinary house current render the temperature
variable, but Mr. Lyster found he could maintain a
perfectly even temperature by using cryptol as a resist-
ance, whilst the amount of current did not exceed 150
milamperes. Mr. C. L. Curties exhibited an arrange-
ment for obtaining dark ground illumination with high
powers by a stop over the objective, which was sug-
gested to him by a contrivance of Leitz. Mr. Curties
observed that only in certain cases were the images
of the markings on diatoms shown by this means to be
considered as trustworthy evidence of their real struc-
tures. Mr. Rheinberg called attention to an experi-
ment, showing that the appearance of a grating could
be produced in the field of the microscope without there
being anything on the stage. ITie lines seen were
achromatic interference bands, produced with the help
of two of Thorp's gratings of equal pitch placed behind
the objective. Mr. Rousselet called attention to a living
specimen of PlumaUlla punctata {Hancock), sent by Mr.
Hood, of Dundee, which has apparently not been
recorded in England since its discovery by Hancock
in 1850. It diflcrs from other species of Plumatella,
mainly in having a soft, transparent ectocyst. Mr.
Nelson communicated a note on the Tubercle Bacillus,
and Mr. A. E. Conrady gave a resumi of his second
paper on " Theories of Microscopic Vision." The pro-
ceedings concluded with an exhibition of fine zoological
lantern slides, lent by .Mr. .\. Flatters.

The Qviekett Microscopical Club.

The 423rd ordinary meeting was held on June 16th, at
20, Hanover Square, W., the I'resident, Dr. E. J.
Spitta, F.R.A.S., F.R.M.S., in the chair,

Mr. \V. VVesch^, F.R.M.S., gave an abstract of his

paper on "The Genitalia of Glossina palpal is," the
Tsetse fly, the host of the " sleeping sickness "
organism. This was shown to be homologous with
certain other flies, though differing in the presence of a
double le\er at the extremity of the central organ, a
feature which also occurs in the cockroach.

Mr. Julius Rheinberg, F.R.M.S., showed an experi-
ment on the production of achromatic interference
bands in a new manner, which formed Ihc subject of
a paper which he had recently read at the Optical Con-
vention. Certain experiments in connection with the
theory of microscopic vision had led to the curious
result in question, which amounted in effect to pro-
ducing in the microscope, on the object stage of which
a piece of paper having a large perforation had been
placed, the appearance as if a grating had been placed
over it, the lines appearing perfectly sharp in black
and white.

Mr. Rheinberg gave a description of the manner in
which this striking interference image was produced.

Mr. Wesche then gave a popular lecture on " Pond
Life," which he hoped would encourage any novices
who might be present to take up this fascinating branch
of microscopy. It was illustrated by a number of
lantern slides prepared from Mr. W'esche's drawings
and designed to show the objects under dark ground
illumination.

The next general meeting of the Club will be on
October 20th, but the usual fortnightly meetings will
be held during the vacation for gossip and exhibition
of objects. There are also several excursions during
the summer months to various collecting grounds.
\'isitors will be welcomed to both meetings and excur-
sions, and may obtain full particulars on application
to the Hon. Secretary, Mr. A. Earland, 31, Denmark
Street, Watford.

Home-Made Dissecting Staind.

I HAVE been several times asked to recommend a dis-
secting stand, and though for convenience the stands
made by Zeiss, Leitz, and Reichert in various patterns
cannot well be improved upon, still the cheapest of
them costs, with two lenses, a couple of sovereigns, and

it may interest many of my readers if 1 describe here
a stand which can be made at home by anyone who can
do a little carpentering and which need cost only a few
shillings. A reference to the accompanying drawings
is almost .self-explanatory. The total length of the
stand should be about 14 inches, and the width about

August, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

213

four inches. The sloping rests for the hands might
be about two inches high at the lowest ends and four
inches at the highest, but these measurements should be
governed by the size of the mirror, which must have
ample room in which to swing. The mirror itself
is a simple round penny mirror, such as can be boug'ht
at almost any toy shop, the larger the better. It is
deprived of its metal cover and let into a piece of wood,
which swings on wooden or metal pivots between the
two centre uprights of the stand. The simplest way in
which to make the support for the mirror is to care-
fully cut a hole of the proper size in a piece of stout
fret-wood, and to back it with another piece of
fret-wood, glueing the two together acd mounting
them on a cross beam, the projecting ends of which
are carefully shaped circular and fit fairly tightly into
corresponding holes. This piece of wood could also
be hinged to the bottom of the stand, but in that case
the mirror would not remain central when tilted at an
angle. A little more skill would be required to arrange
universal movements, but they are really not neces-
sary. The stage is a piece of plate glass, 5 by 4 inches,
ground at the edges, and can be ordered from anv glass
shop for a shilling or so. It lifts out if necessary. Two
pieces of cardboard of the same size should be cut to
go underneath when required; both should be covered
on one side with black and the other side with w'hite
paper, and one should have a hole about li inches in
diameter in the centre. The whole stand might be
made of wood § inch thick, mahogany or walnut being
preferable to pine, and the dove-tailing or grooving
should be done and finished off r.s carefully as possible.

The holder for the lenses can be made, as illustrated,
by fitting a piece of J-inch brass tube about eight inches
high into a small stand about 2i or three inches in
diameter. A piece of springy ^-inch brass wire is then
rolled several times round the upright, as shown; one
end is turned up about three inches away from the
stand, and the other end is shaped intO' a ring to hold
a watchmaker's eye-glass. Tliis last can be bought
anywhere for about lod. or a is., and makes a most
useful dissecting lens. On the turned-up end can be
put an ordinary pocket magnifier in ebonite mount,
such as can be bought for a shilling and upwards,
according to the number of lenses.

This stand, simple as it is, will be found a useful and
errcienl piece of apparatus. It will be money well
spent if the worker provides himself, however, with one
of the beautiful aplanatic lenses sold by all the principal
opticians. They give exquisite definition, together with
a flat field, and being much less tiring to the eyes are
excellent for dissecting, and are also the most perfect
ol those magnifiers which the real microscopist can
always bring forth from his pocket when wanted. The
most useful powers do not exceed ten diameters, and
a lower power gives a larger field and greater working
distance. Perhaps six is the most useful and convenient
magnification.

Botanical Microscopical Slides.

Mr. A. Pexistox, of 5, Montpelier Terrace, Leeds, has
sent me a catalogue of botanical slides which contains
a novel feature in th.'t it not only gives the principal
features of the slides referred to, but in many cases
adds outline descriptive illustrations. Many of the
slides are also quite out of the ordinary run, amongst
which I observe a slide of oedogonium, showing
oogonia and so-called " dwarf males," early stages in

the development of antheridia, developing pollen-tubes,
etc. The prices are very moderate and the whole list
shows evidence of having been the work of a botanist
and not a mere mounter.

Answers to Correspondents.

O. H. Sdi-geut, York, IT. Australia. — I am afraid that the
difficulty to which you refer is, as you suggest, inherent in deep
eyepieces when used with ordinary achromatics. Few of such
objections will satisfactorily bear eyepiecing above 10 times,
and even then the loss of light and depreciation ofthe image is
noticeable. If your eyepiece is capped, it is just possible that
this is not correctly adjusted. Possibly also you are using a
larger cone of illumination than your objective will stand.
Few objectives will bear a cone equal to their own aperture
and a two-thirds or three-quarter cone is generally ample.
Vou can judge of the size by removing the eyepiece and look-
ing down the tube. All camerae lucidae require considerable
practice before satisfactory results are obtained. You would
probably find the Swift-Ives type as easy to use as the .^bbe,
but it too requires practice. The great secret is the careful
adjustment ofthe light, and I think the best way is to have two
lamps, one to illuminate the object in the microscope and one
to illuminate the paper on which you are drawing. The flames
of each lamp can then be carefully adjusted, until the bright-
ness of the microscope field does not overpower the illumina-
tion of the paper, or vice versa. You will find very different
adjustments are required for any change of magnification, I
Ihuik you will find an ordinary twelfth immersion objective of
N.A, 1-25 or so perfectly satisfactory, and there is very litile
to choose between those made by the leading makers. The
cost will be £5. But all your objectives must be used with the
tube-length for which they are corrected. As vour eye be-
comes more trained yon will perceive this yourself, especially
for such critical work as cytology. The study of the pollina-
tion and fertilization of \V. Australian plants ought to prove an
almost inexhaustible field for work of all kinds if you work at
it steadily and earnestly,

A. I. Robinson, Portsmouth. — I have had no experience my-
self in mounting diatoms in either carbon bisulphide or
quinidine, and the nearest reference I can give you is a
method by Mr, A, W, Griffin on mounting in solution of phos-
phorus in carbon bisulphide, which has a very high refractive
index but needs great care. As a precaution against getting
the phosphorus under the finger nails it is best to well oil or
vaseline the hands. Procure some clean, semi-transparent
phosphorus, cut off some pieces under water with a pen-
knife, place them for a few seconds on blotting paper to free
them from any least trace of water, and dissolve in carbon
bisulphide, say, one drachm of phosphorus in two drachms of
the solvent. When quite dissolved, slightly damp a piece of
filter-paper with bisulphide, and carefully filter into a small
stoppered bottle through a very small glass funnel. Support
both funnel and filter paper in a basin of water to prevent
accident, and have the basin handy throughout in order to
place in it any article which has been touched by the phos-
phorus solution, in order to prevent accidental combustion.
Supposing the diatoms are preserved in water or spirit, place
a drop of the fluid on the cover-glass and slowly evaporate
the medium over the flame of a spirit lamp or jet of gas.
When the cover-glass is quite cool place on the margin of its
edge a mere speck of Canada balsam, the object of which is
to keep the cover, with its surface covered with diatoms, face
downwards, in the centre of the glass slip. By means of a
pipette take a few drops of the phosphorus solution and place
them on the edge of the circle, and by capillary attraction
they will be at once drawn under, displacing the air in their
progress. Having ascertained that the diatoms are completely
immersed in the medium, remove all superfluous particles of
phosphorus with a piece of blotting paper damped with
carbon bisulphide, and consign it also to the basin of water.
Ring with glucine or Kay's coaguline, put aside to dry for six
hours or more, ring again, and then, if preferred, ring finally
with shellac, varnish or asphalt.

[Communications and enquiries on Microscopical matters are invited
and sliould be addressed to F. Skillington Scxla, "Jersey,"
St. Barnabas Road, Cambridge.']

214

KNOWLEDGE & SCIENTIFIC NEWS.

[August, 1905.

The

Face of the
for August.

By W. Shackleton, F.R.A.S.

Sky

The Sun. — On the 1st the Sun rises at 4.24 and sets at
7.48 ; on the 31st he rises at 5.1 1, and sets at 6.49.

Sunspots are numerous: also recent spectroscopic ob-
servations of the Sun's limb have shown many bright
and active prominences.

The position of the Sun's axis and equator, required for
physical observations of the Sun, is indicated in the fol-
lowing table: —

Date.

Axis inclined from N.
point.

Equator S. of
Centre of disc

July 30 ..
Aug. 9 ..

.. 19 ..

„ 29 ••

id" 6' E .
n° 59' E.
17= 28' E.
20° 28' E.

5° 45'
6° 24'
6° 53'
7° 10'

An eclipse of the Sun takes place on the 30th ; in this
country it will be observable as a partial one ; three-
fourths of the diameter being obscured in the southern
co'-inties, diminishing to about one half in the Orkneys.
From suitable positions in Canada, Spain, Algeria and
Kgvpt the eclipse may be observed as a total one.

The particulars for London are as follows, whilst
the diagram illustrates the appearance at maximum
phase : —

At Greenwich, partial eclipse (Sun's diam. = i),
magnitude 0-786 :

Begins . . . . Aug. 30, 11 h. 49-1 m. a.m.

Greatest Phase . . „ „ i 3'5 p.m.

Ends . . . . „ „ 2 15-1 p.m.

Eclipse

The Moon

■A visible In London, i.o p

.m. Au^u

»t 30.

Date.

Phases.

Aug. I ..
.. 7 ••

.. 15 ••
.. 23 ••
„ 30 •■

• New Moon

J First Quarter
0 Full Moon
d Last Quarter

• New Moon

4
10
3
6
I

3 a.m.
17 p.m.
31 a.m.
10 a.m.
13 pm.

A partial eclipse of the Moon takes place on the morn-
ing of the 15th. At Greenwich, however, the Moon sets
before it is quite out of the shadow.

First Contact with the Penumbra, Aug. 15 i 9'5 a.m.

,, „ ,, Shadow, „ 2 389 „

^liddle of Eclipse . . . . ,, 3 41-0 „

Last Contact with the Shadow „ 4 43-1 „

,, „ ,, Penumbra ,, 6 12'5 ,,

At Greenwich the Moon sets . . ,, 4 53 >>

Magnitude of Eclipse (Moon's diameter = i), 0'292.

Appearance of Moon at Aliddle of Eclipse, Aug. 15.

The Planets. — Mercury, at the beginning of the
month, is an evening star in Leo; he is at greatest
( asterly elongation on the 2nd, when he sets about one
hour after the Sun. On the 30th, the day of the solar
eclipse, the planet is in inferior conjunction with the Sun
at 3 a.m., and at the time of the eclipse the planet is
about 4= towards the S.W. of the Sun.

Venus is a morning star in Gemini, rising shortly after
I a.m. throughout the month. On the 30th, the planet
will lie situated about 31) W. of the eclipsed Sun, where
search should be made at the time of maximum phase, to
ascertain if the planet is visible in the subdued light.

Eros is in opposition on the 7th, but being in the
neighbourhood of its aphelion it is not a favourable
rpposition.

Mars is due south about 6 p.m. near the middle of the
month, when he sets about 10 p.m. The planet is not
well placed for observation, as he appears low down in
the sky, and on account of increasing distance from the
earth his lustre is diminisiiing.

Jupiter rises at 11.30 p.m. on the ist and at 9.45 on
the 31st. The planet is situated in Taurus, a little
south of the Pleiades.

Saturn rises about 7.40 p.m. on the 15th, when he is
on the meridian shortly after midnight. W'c are looking
down on the northern surface of the ring which appears
open at a smaller angle than of late years.

Uranus is on the meridian about 8.30 p.m. on the
15th. He is situated about 2i south of the 4th
magnitude star ^ Sagittarii.

Neptune does not rise until after midnight.

Meteors : —

a i

Aug. 10:2 45" -fS?" Great rcrsnii shower ; radiant

moving E.N.E. about 10
per day.

215

KDooiledge & Seientlfle tms

A MONTHLY JOURNAL OF SCIENCE.

Conducted by MAJOR B. BADEN-POWELL, F.R.A.S., and E. S. GREW, M.A.

Vol. II. No. 10. [new series.] SEPTEMBER, 1905. [stalSners' Haii ] SIXPENCE NET.

CONTENTS.See Page VII.

The

Sun. in Calcivim Light.

By William J. S. Lockyer, M.A., Ph.D., F.R.A.S.

II.

The loaded plate-holder is next slid into its carrier,
and both secondary slit and carrier are securely
wrapped in velvet as is consistent with the necessary
freedom of relative movement during the exposure.
The window blinds in the room containing the instru-
ment are then closed to keep out daylight as much as
possible. By pushing the whole upper framework to-
wards the east, the solar image is made to lie a little
to the west of the primary slit. The length of exposure
required is now judged by the brightness of the solar
image, and the rate of movement adjusted according to
a reading taken from a table giving the lengths of
" runs " corresponding to the temperature of the oil.
The dark slide is next opened and a suitable moment
for exposure awaited. When this opportunity occurs
the shutter behind the primary slit is opened and the
framework released by a starting handle.

The primary slit then moves over the fixed solar
image and simultaneously with it the secondary slit
passes over the fixed photographic plate; the " K "
image is thus built up in the fcrm of a disc. The time
of transit of the slit over the image is indexed as the
" run," and when completed the slit shutter and plate
are closed.

The operations for obtaining the photographs of the
prominences round the limb are very similar to the
above. The solar image falling on the primary slit is
blocked out by means of a metal disc of the same size
as this image, and a much longer exposure is given.
The ratio of the length of a " disc " and " limb " ex-
posure is about as i to 60. Under very favourable
circumstances a " disc " exposure lasts about 15
seconds.

By taking a limb photograph first, and then removing
the metal disc and making another " run " for the
" disc," a composite picture on one plate is secured.

Since this spectroheliograph has only been working
efficiently since the spring of last year (the recent winter
months being excluded as the low altitude of the sun in
London during this period renders this kind of work
almost impossible), the data at present available for
discussion are not very considerable.

It will, however, not be without interest to refer to
some of the photographs obtained, which will serve to
illustrate not only the quality of the negatives secured,
but the different branches of work which such a series
of photographs as previously mentioned open up.

In the accompanying illustrations will be found two
enlarged reproductions, one of the solar disc in " K "
light, taken on September 20, 1904 (Plate II.), and
another of a composite picture showing the limb and
disc taken on August 29 of the same vear (Plate III.).

From a general examination of a great number of
the " disc " negatives it has been noted that over the
whole solar surface there is always a very distinct
" mottling " extending even to the solar poles.

Illustrating a striking change in a prominence after
an interval of one hour. July 14. IQ04.

About the equatorial regions this mottling seems in
places to be of an enlarged nature and unevenly dis-
tributed in longitude. In regions of apparently greater
disturbance the bright portions of this mottling become
amalgamated and produce the calcium clouds or
" flocculi," as termed by Prof. Hale. The type of
formation of these flocculi can be gathered from the
illustration (Plate I., Fig. 2) given last month. A
bright nucleus with radiating bright branches is not an
uncommon feature in a great number of the plates
examined.

It is in these larger flocculus regions that spots are
observed. There can be flocculi without spots and
flocculi with spots, but, so far as the photographs have
shown, never spots without flocculi. The duration of
a spot is, further, only a brief interval in the life history
of a flocculus, so that to study the formation of spots
their relation to flocculi must be taken into account.
That an intimate connection in addition to that men-
tioned above does exist, is indicated by the fact that
spots appear more generally to precede the apparent
trailing masses of flocculi with respect to the solar

2l6

KNOWLEDGE & SCIENTIFIC NEWS.

[Sept., 1905.

rotation. Some examples of these are shown in one of last
month's illustrations (Plate I. Fig. 3)-

These " K " line photographs of the disc of the sun
will thus form the means of helping to solve many of
the solar riddles. Several other equally interesting
points to be investigated might be mentioned.

By photographing the solar limb and the disc on the
same plate a means is afforded of noting the behaviour

tion angle, neither does a flocculus passing round the
limb necessarily indicate the position of a large
prominence. In fact, it seems that although there may
be some relation between prominences and flocculi, it is
not a verv close one so far as can be judged by the few
photographs already discussed.

The spectroheliograph affords a very excellent means
of studying the sequence of changes in the form of

PLATE II.— Sun's Disc F'hotoxraphed in "K" (Calcium) Li>;ht. feptcmbcr 20, 1904-

Exposed from lo h. 2S •". o ». to loh. 20 m. io>. int(r\iil 70 .sec .
(EnlarKcd 2! times.)

of prominences with reference to the flocculi. Thus it
has been observed that although the " K " prominences
near the solar poles are sometimes of very great dimen-
sions, the mottling on the disc in these latitudes is
always regular and apparently undisturbed. Ag:iin, a
large prominence on the approaching limb of the sun
in lower latitudes does not always herald the presence
of a large flocculus region on the disc at the same posi-

prominences. If the instrument be set up in low lati-
tudes where the altitude of the sun is high at noon all
the year round, and, consequently, the length of ex-
posure necessary can be reduced to a minimum, a
wealth of valuable information could be gleaned. In
these latitudes, even in summer, opportunities arc not
very numerous owing to the frequency of cloudy days.
To illustrate the nature of such photographs one

Sept., 1905]

KNOWLEDGE & SCIENTIFIC NEWS.

217

example is here given. This is shown in Fig. 4, and
was secured on July 14 of last year, and the plates
were exposed at iih. 8m. a.m., and i2h. 8m. p.m.
respectively. It will be seen that during this interval
of about one hour a very decided change of form in the
largest prominence has occurred. Instead of the some-
what symmetrical shape that existed at the first of

For very rapid changes of form in individual
prominence, that is, changes that occupy only a few
minutes of time, the visual method must still be em-
ployed, a most convenient form of instrument for this
purpose being the Evershed form of spectroscope.

From the above somewhat cursory account of this
spectroheliograph and its first fruits, it is hoped that

PLATE III.— The Sun as Photographed in "K" Light on August 29, 1904.

Exposure for Limb 2 h. 40 m. to 3 h. 13 m. Q.Vl.T. (interval 24 m.l.
Exposure for Disc 3 li. 16 m. 5 s. to 3 h. 16 m. 30 s. G.M.T. (interval 23 s.).

these times the prominence is most intense on the left-
hand side, and the material appears to be thrown to-
wards the right as if acted upon by a strong current.
Its height, at the same time, has been considerably
increased. The other very intense but smaller
prominence has almost disappeared during the same
interval.

some of our more wealthy readers will be induced to
take up the work and carry out one or more of the
numerous branches of this research which are as yet
untouched. Although the initial expense is somewhat
costly, the investigation of the sun by this instrument
is so full of interest that the labour involved is sure to
be well repaid.-

2l8

KNOWLEDGE & SCIENTIFIC NEWS.

[Sept., 1905.

The N-Ratys^f Blondlot

By J. J. Stew.\rt,M.A.,B.Sc. {Priiici/'al 0/ the Tfchniiiil

Institute, Nrwfort).
In the early summer of the year 1903 M. Blondlot, of
Nancy, published in the Comptes Rendtis of the French
Academy of Sciences an account of some remarkable
experiments he had carried out on certain rays which
were emitted by a gas burner. He found that an
ordinary .Auer burner sent out rays resembling those
of light and capable of penetrating metals, black paper,
wood, cardboard, &c. The rays, after passing through
these obstacles in their path, were able to produce
effects in the region beyond. These effects manifested
themselves especially by their behaviour towards a
small electric spark which they caused to become
noticeably brighter. A record of this action was ob-
tained by M. Blondlot, who arranged a pair of sensitive
photographic films so that one was acted upon by the
ordinarv electric spark from a small induction coil, the
other by the spark from the same coil under similar
conditions except that in the second case the spark
was excited by the presence of the rays and had thus
become brighter. The enhanced brilliance of the spark
is indicated by the different effects on the sensitive film,
and pictures of the two films, one exposed to the action
of a succession of sparks under the influence of the rays
from the Auer burner for 40 seconds, and the other
with the rays from the .Auer burner cut off by the inter-
position of moistened paper, are given in an early paper
by ^f. Blondlot. The absorption of these new rays by
water, especially water containing salt in solution, or
by moist paper is one of their remarkable and unex-
plained characteristics.

The emission of these rays was noticed by M. Blond-
lot when using a Crookes tube for the production of
Rontgen rays. He was led to suppose that they were
to be very generally met with and were given out by
various sources of light and heat, such as an Auer
burner or a piece of hc.ited metal. \s these researches
were carried out at the University of Nancy, where
M. Blondlot is one of the professors, he gave to the
radiations the name of X-ravs from the first letter of
the name of the town. Experiments on the behaviour
of the N-rays seemed to indicate that they were capable
of refraction and polarisation like the rays of ordinary
light, and a beam of the rays appeared to be made up
of different rays of very various refrangibility.

.Another strange property of the new rays was that of
increasing phosphore.scence. Thus, if the N-rays con-
centrated by a quart/! lens were caused to strike upon
a screen of sulphide of calcium already phosphorescing,
the phosphorescence was increased. This has been
used as a means of detecting the presence of the rays,
but the effect of heat on phosphorescence is very similar.

Further investigation of the N-rays seemed to
indicate that they were given out by all bodies in a
state of strain — by a bent piece of steel, a stretched or
bent rod, or a file in which, during the process of
manufacture, the malf-rial was subjected to stress re-
sulting «n a state of permanent strain. Extraordinary
accounts were given of the emission of N-rays from
pieces of metal, such as old weapons found in ex-
cavated cities or amongst the remains of buildings
dating from Roman times in the south of France.

Bending or stretching wood or metal was found to
cause the emission of N-rays, which generally mani-
fested themselves by causing increased phosphore.scence
in sensitive substances.. Sonorous vibrations were

next observed as exciters of N-rays. M. Mace de
Lepinay gave an account of experiments which showed
increased luminescence of sulphide of calcium in the
presence of sonorous bodies, such as cylinders of
bronze when set in vibration. Even the alternate com-
pressions and rarefactions of the air when transmitting
the vibrations of sound seemed sufficient to originate
N-rays and increase the brightness of a phosphorescing
screen.

Further investigations by Blondlot led him to de-
scribe the dispersion of N-rays when refracted through
prisms made of aluminium. As source of the N-rays
in these experiments a Nernst lamp was used shut up
in a cvlinder of sheet iron in which a slit for the exit
of the rays was arranged, which was closed bv a sheet
of aluminium permeable to the rays. The issuing
N-rays were caused to pass through an opening in
moistened cardboard (itself impermeable to them), and
thus a beam of the rays was got, which was caused to
pass through the aluminium prism and appeared to go
out from it by another face, making an angle with the
first, signs of dispersion by the p'ism being given in a
wav analogous to that of beams of light. The N-rays
were drawn out into a spectrum — they appeared to be
made up of various rays differing in wave-length.
Measurements of the length of wave arc given by M.
Blondlot in his papers. He endeavoured to get a
measurement of it by a sort of grating, and diffraction
fringes were obtained. The phenomena of Newton's
rings were also oljserved, and a whole series of
phenomena resembling those obtained with waves of light.

Photography was employed to give a record of the
ch.anges of brightness produced bv the N-rays, and the
results got by Blondlot were confirmed by various ob-
servers in France. A remarkable thing about the re-
petition and confirmation of these experiments was that
thev occurred only in France. Observers in other
countries endeavoured to repeat Blondlot's experi-
ments, but with no satisfactory result.

A strange development of the work r)f research
occurred when M. Blondlot published an account of a
new sort of N-rays, which, while resembling those
already described, had in many cases an inverse effect.
They diminished instead of increasing the brilliance of
a small electric spark when they fell upon it, and ihiv
caused a decrease in the phosphorescence of a sulphide
of calcium screen. These rays it was proposed to
call N'-Rays. Another property, both of these new rays
and the N-rays themseUes, was, that they become
stored up in substances on which they strike. .\ brick
exposed to the rays of the sun seems to absorb N-rays
and give them out afterwards. A curious effect next
noticed was that a screen feebly phosphorescing and
expr)sed to the action of the N-rays, when \iewed
normally by a person straight in front of it, :i()[)carc(l
more luminois than before, whilst itbecame less himirous
if looked at very obliquely or almost taneentially.

Further researches were carried out on the trans-
parency of different substances to the N-rays, and they
were found to vary very much in this respect. .Silver
was foimd to be particularly transparent, and nickel
and some other metals opaque to these rays.

The investigations were next taken up by v.-irious
physif)logists, especially M. Augustin Charpentier, of
Nancv, who described how streti'hefl muscle gave out
N-rays. f'hosphorescenco was produced on a screen
of barium platino-cy.-niidc bv means of a salt of r:idium,
and it was found that on bringing up various pf)rlions
of the human body to the screen the brilliancy of the
phosphorescence was increased. Mus;le and nerve

Sept., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

219

especially were observed to produce this effect, and
muscle appeared to act more powerfully in proportion
as it more strongly contracted. The effect was not
due to heating of the screen, which would also tend to
increase the phosphorescence, for means were taken
to guard against this. M. Charpentier was led to the
conclusion that the human body itself emitted N-rays.
Further experiments seemed to show that from the
frog and other animals N-rays were sent out. The
portions of the body rich in nerves especially mani-
fested this peculiar influence, and brightening of the
phosphorescent screen was observed when such por-
tions of a living organism were brought up to it. The
compression of a nerve noticeably increased its power
of vivifying the brightness of a glowing screen. Cer-
tain portions of the brain were especially active in
giving out N-rays, and these portions could be localised
on screens by the increased brightness which thev pro-
duced. The behaviour of these radiations seemed to
vary, and it was thought that the effects were due to
rays which differed somewhat amongst themselves.
The rays coming from nerve and brain were found to
be stopped by a thin sheet of aluminium, while those
proceeding from the heart, the diaphragm, and various
muscles passed readily through aluminium and mani-
fested their effects beyond the interruption.

Meanwhile M. Blondlot had been continuing his in-
vestigations, and various strange results were obtained.
On examining still further the effect of compression he
found that a large number of different substances
acquired through pressure upon them the power of
emitting the rays. Pieces of wood, glass, and
caoutchouc behaved in this way. During compression
they became sources of N-rays and increased the faint
phosphorescence of a calcium sulphide screen. They
also appeared to act directly on the retina (which is the
result of the emission of N-rays), and caused the action
of light upon it to be intensified. Thus, when the ob-
server looked upon the face of a clock in a partly
darkened room, which was so dimly lit that the clock-
face was scarcely visible, and then bent a cane near
his eyes, the compression of the cane had such an effect
on his retina that the clock-face became clearly visible
and the figures could be read.

Compressed glass had the same effect. These
phenomena were not instantaneous; time was required
for the effects to be observed. Bodies which were in
a state of internal constraint were sources of N-rays.
Tempered steel, hard-hammered brass, and crystalline
sulphur were found to be permanent sources of these
rays. A file or a tempered knife-blade acted like the
compressed cane in brightening a clock-face in a dark
room or in strengthening phosphorescence in a sheet
of suitable material already e.\citcd. This emission of
these mysterious rays apparently lasted for an inde-
finitely long time. A tempered' knife-blade from an
ancient Gallo-Roman tomb, as well as other similar
ancient objects, behaved just as did a recently-made
knife-blade. They emitted rays. The ravs thus got
in so remarkable a way were analogous to those of
light. Spectra could be got, and the rays were cap-
able of reflection, refraction, and polarisation, as are
those of light. The energy thus appearing M. Blond-
lot considered was furnished by the potential enerev
which corre.sponds to the state of constraint of tem-
pered steel.

fOur readers are doubtless aware that many experi-
menters have quite failed to obtain similar results. -

Flint Implements
Fovmd by Accident.

By VV. G. Clarke.
Many finds of Neolithic flint implements are in the
nature of a surprise, as the following instances will
suffice to prove. A Methwold farmer walking along
the edge of one of his fields was attracted by a gleam
of white at the foot of the hedgerow. Investigation
disclosed a polished axe, curiously enough the only
implement ever found on the farm. In this instance
the finder knew what his discovery was, but a labourer
at Flegg Burgh, Norfolk, was not so fortunate. He
was ploughing and uncovered three axes lying side by
side — two of polished white flint and one of chipped
black flint. Thinking there was something uncanny
about them, he kept the flints for a year to see if they
would grow. As they did not, he made inquiries, and
eventually found a purchaser. Numerous implements
have been found projecting from earthen boundary
banks. Such was the case with a fine axe firmly em-
bedded in a roadside bank between Weeting and
Brandon, and pulled out by a woodman struck by its
unusual shape. Even more curious was an instance
which occurred near Thetford. In the footpath leading
to a gamekeeper's house there was a white stone, level
with the surface and trodden upon by almost every
passer-by. One severe winter it became loosened by
frost, was kicked up by the gamekeeper stumbling
against it, and found to be a white flint axe of the
Cissbury type. As an example of a remarkable
coincidence the following is noteworthy. Three men
were walking over a heath in North-West Suffolk.
They were not searching for flint implements, but the
two outside men stooped down simultaneously and
each picked up a perfect arrow-head. Even more
strange is the history of the finding of the finest
Neolithic axe yet recorded from East Suffolk. Be-
tween Carlton Colville and Kirkley, a railway line
only used for goods traffic passes through a cutting.
Abutting on this at one time was the playing field of a
local school. One day as the boys were playing, a
football was kicked into the cutting, and when the
headmaster jumped over the fence after it he dislodged
a big stone, which rolled down the slope. Its shape
attracted attention, and he found that he had un-
wittingly unearthed a treasure. On one occasion the
writer was searching the sides of a pit when suddenly
a number of wasps came from a hole. Quickly
stepping down the slope he disturbed a glisteninp- piece
of flint which proved to be a one-tanged lance-head of
most beautiful workmanship. Many good implements
have been found on stone-heaps. Some years ago Mr.
E. T. Pengelly visited Norwich to give a lecture on
Kent's Cavern. Prior to the meeting he had a short
ramble, and from a stone-heap near Old Lakenhnm
Church picked up a polished axe. .Somewhat similar
was the case of a labouring man at West Harling, who
noticed a golden-coloured stone on a heap which had
been collected from a field. He removed it, and it was
seen to be a double-headed axe of yellow flint, magni-
ficently chipped, and so thin as to be almost trans-
parent; in fact, one of the best known English speci-
mens. Numerous other examples could be given, but
these are sufficient to prove that all Neolithic flint im-
plements are not found as the result of systematic
search, and that an element of chance enters into the
discovery of some of the very best examples.

KNOWLEDGE & SCIENTIFIC NEWS.

Sept. 1905.

The "Tele ©Lctivity'* of
ChemicoLl ResLctions.

Many readers of " Knowledge " will, perhaps, be sjlad
to hear of some research which offers an unlimited field
for experiments, and which may also prove to be of
some importance in several branches of manufacture.

Resonance in sound is familiar, both in practice and
theory, to everyone ; wireless telegraphy is an example
of electrical resonance ; in the former, the effects are
produced by vibrations in the air ; while, in the latter,
the ether is the medium which transmits the disturb-
ances. It does not require a very great effort of imagi-
nation to conceive that something similar may take
place when waves in the ether are produced by means
of a chemical reaction.

With the object of investigating this, several experi-
ments have been proposed and carried out, but the re-
sults up to the present have not Ijeen very conclusive.

Two substances (mercury and iodine), which combine
readily at ordinary temperatures to produce a com-
pound easily recc^nised, were placed together in an
open vessel. .V vigorous chemical reaction (sulphuric
acid on potassium chlorate and sugar) was allowed to
take place very near it, and the mercury and iodine
were afterwards compared with a similar mixture which
had been prepared at the same time, and kept in another
room. The amount of mercuric iodide protluced in the
protected vessel was much less than in that which had
been exposed to the reaction. It was suggested that
the heat produced by the reaction would account for the
difference, and so the experiment was repeated with an
asbestos mat placed over the vessel to shut off the heat,
a thermometer being placed with the mercury. 'Ilie tem-
perature did not rise, but the effect was not as marked
as before.

A photographic plate was then exposed to the same
reaction fwell protected, of course, from light rays),
and when developed the image of lines on a piece of
paper could l)e clearly seen. This, perhaps, may be ex-
plained in some other way.

It was then decided to determine whether one reac-
tion would accelerate another. Two solutions were
prepared containing the same quantities and proportions
of sodium thiosulphate and hydrochloric acid. One
was removed as before, while the other was exposed to
the chlorate reaction. In every case it was ob.serx'ed
that sulphur was deposited more quickly in the solution
expo-sed to the reaction. These experiments were re-
peated, using blank cartridge to produce the disturb-
ance, and very decided results were ;i^ain obtained.

The strengths and proportions of the solutions were
varied considerably : —

H CI I cc. (cone.) in 25 cc. water, to

I cc. „ in 50 cc. water.

Na, S, 0» I gr. in 125 cc. water, to

I gr. in 75 cc. water.

Proportions taken —

5, 10, 15 H CI with 20. 25, 50 Naj S^ 0;,.

-Similar experiments were tried, using hydrogen per-
oxide and potassium iodide (with a little starch to .show
separation of iodine). The effect of the explosion was
always to cause a sudden coloration of the solution,
while an exactly similar solution prepared at the same
time, but not exposed to the explosion, did not change
colour until several minutes later.

About a week afterwards, these experiments were
repeated ; the results observed were similar to. I)ut iim
as decisive as, those mentioned above.

Tlie effect of the explosion of nitrogen iodide on a
mixture of hydrochloric acid and sodium thiosulphate
solutions, using same strengths as before in propor-
tion of 10 to 50 cc, was a scarcely perceptible difference
in the rates of deposition. When the proportions were
altered to 13 to 50 cc, the difference was very decided.

The above results were thought to be due to the
shaking produced by the explosion, but it was found
that there was no difTerence in the rates of deposition of
the sulphur, if one were shaken mechanically, and the
other not.

Iioth chemical combination and decomposition have
been employed to affect another reaction at a distance,
but in all cases the results, when critically examined,
were hardly decided enough to warrant the assertion
that one chemical reaction can be influenced by anotlier
when there is no apparent communication between
them, .^n accident, however, showed th;it this was at
least possible. A large quantity of the chlorate and
sugar mixture had been made up in proportion not
noted. A little of this was placed in a basin, and while
the rest of the mixture was held behind the operator, in
a large mortar, strong sulpiiuric acid was added to the
former, causing it to ignite in the usual way. Immedi-
ately afterwards, the rest of the mixture blazed up,
although it was impossible that sulphuric acid could
have got to it.

Similar mixtures in a great number of different pro-
portions have been prepared and tried, but up to the
present the exact proportions necessary for a repetition
of the above phenomenon have not been ascertained.

It was thought that the desired result might, perha"s,
be obtained if the two mixtures were cornected in
some way — by a wire or piece of glass tubing — but
these methods have given no results. TIic experi-
ments have been tried using similar and dissimilar
substances : — Chlorate and sugar on a similar mixture;
nitrogen iotiidc on nitrogen iodide; chlorate and sugar
on a mixture of these substances, but in different
proportions ; chlorate and sugar with nitrogen
iodide ; also strong sulphuric acid and water,
strong acids and solid caustic soda have been
used as primary reactions, molecular proportions
always being employed. When solid substances are
used, the effects are not obtained, probably because the
substances or prf)portions are not "in tunc"; while when
liquids are used a certain amount of action is observed,
but the greatest possible effects are not produced.

One other experiment awaits a satisfactory explana-
tion : .Some nitrogen iodide had been prepared and
kept for nearly a month suspended in a solution of
ammonia. The day on which its services were re-
quired had been devoted to a large number of ex-
perimcnls with potassium chlorate and sugar. The am-
inoniacal nitrogen ifxlide solution was carried across
the laboratory, with the object of being filtered and
dried, and placed on the bench where the above experi-
ments had just been carried out. It had only been there
five seconds at the most, when it exploded with its
customary violence.

Of course it may be only a coincidence — even then,
the object of the investigation is to explain these "coin-
cidences"— or it may be that a violent chemical reaction
converts the space in its immediate vicinity into a
medium that will accelerate or even induce chemical
activity. This latter docs not appear an impossible ex-

Sept., 1905]

KNOWLEDGE & SCIENTIFIC NEWS.

planation, and it should be thoroutjiily investig-ated be-
fore being rejected.

If it be true that one reaction docs influence another,
the importance of the invcstig-ation cannot be over-
estimated. The preparations and violent reactions
that go on from day to day in a laboratory may be
altering (and those accustomed to manage a chemical
laboratory know how certain substances do unaccount-
ably alter) the molecular arrangement of the substances
in the neighbourhood of the demonstation benches.

This, moreover, raises the question : " Does the
weather influence the communication between one
chemical reaction and another?" As has been stated
above, it was observed that the results of the experi-
ments varied (in degree) from day tO' day.

A thorough investigation of this subject may shed a
new and more satisfactory light on the cause of intra-
molecular action.

Among the few experiments described above, there
may be some that will suggest others which will lead
to more decided and consistent results, so that if it be
possible tO' control chemical reactions at a distance,
further research would show how it can be most effi-
ciently demonstrated.

A. F. B.

B. 1.

Practical Meteorology.

II.-RainfaLll.

By William Marriott, F.R.Met.Soc.

In the present article it is proposed to deal only with
the rain after it has reached the earth. In the term
" rainfall " is included rain, snow, hail, dew, mist, &:c.
The rainfall is always expressed in inches, and is sup-
posed to represent the height to which the rain would
rise on the level ground if none of the water were per-
mitted to run off or percolate through the soil, or to
evaporate.

The instrument used for measuring the rainfall is
called a rain gauge. This is best made of copper, and
should have a circular funnel of five or eight inches
diameter. It is very desirable that it should be of the
Snowdon pattern, which has a deep rim tO' retain snow
(Fig. i). The gauge should be placed in an open
and well-exposed situation free from trees, walls, and
buildings; and should be firmly fixed so that it cannot
be blown over. The top of the funnel should be one
foot above the ground, and be quite level. The
measurement of the rain is effected by pouring out the
contents of the can or bottle into the glass measure
and reading off the division to which the water rises.
The gauge must be examined daily. When snow falls,
that which is collected in the funnel is to be melted by
adding a known quantity of warm water, and entering
the difference as rain.

Rain gauges should not be placed on walls or roofs,
as the buildings themselves offer obstructions to the
wind which carries the rain drops over the funnel and
so gauges mounted in such positions collect less rain
than those placed on the ground. This was demon-
strated as far back as 1766, for in that year Dr. W.
Heberden, F.R.S., had three rain gauges at work at
Westminster — one on the roof of the dwarf tower of
the Abbey, one on the roof of a house close by, and

another in the garden of the same house. The amounts
of rain collected by these gauges were : — •

Tower of Westminster Abbey

Roof of house

Garden

1210 inches
18-14 ,.
2261

These differences were due almost entirely to the
action of the wind.

Through the influence of Mr. G. J. Symons it was
agreed some years ago to adopt 9 a.m. as the hour at
which the rainfall should be measured each day, and
the amount entered to the previous day. There had
been much diversity in this matter, observers measuring
the rain at various hours, e.g., 8 a.m., 9 a.m., 10 a.m.,
noon, 3 p.m., and even midnight. As there are now
nearly 4,000 observers in the British Isles, 9 a.m. is
evidently the most convenient hour to the vast majority,
and its adoption has secured uniformity in the measure-
ment of rainfall.

Fig. I.— Snowdon Pattern Rain Gau?e.

In hilly and mountainous districts, and in places
where it is not possible to visit the rain gauge daily,
the contents of the gauges should be measured monthly,
the morning of the ist of the following month being
chosen for the purpose. These mountain gauges must
be of sufficiently large capacity to contain the month's
rainfall.

As everyone knows, the rainfall is very irregular,
but, as a rule, there is most rain in the autumn and
winter, and least in the spring. The following figures
gi\e the average monthly rainfall at the Royal Ob-
servatory, Greenwich, for the 89 years, 181 5-1903 : —

January-

1-80 ins.

July

245 ins.

February

1-52 ,,

August

2-33 ..

Marcli

1-52 ,.

September

2-25 ,.

April

i-6i ,,

October . .

2-72 ,.

May

1-95 ■•

November..

2-29 ,.

June

1-97 ..

December . .

I 95 ■■

Total for the year

24-36

ms.

It will thus be seen (Fig. 2) that October is the
wettest month with 2.72 ins., and that February and
March are the driest months with 1.52 ins. each.
Although the above values represent the average rain-
fall, the individual monthly falls are often greatly differ-
ent. For instance, with regard to the month of
October, the fall in 1834 was only 0.47 in., whilst in
1880 the fall was as much as 7.65 ins. Again, with

222

KNOWLEDGE & SCIENTIFIC NEWS.

[Sept., 1905.

regard to the month of Februarj', in 1821 the fall was
0.04 in., whilst in 1866 the fall was 4.03 ins.

Owing to the great variability in the rainfall, it is
very desirable that the averages should be based upon
as long a period as possible; most of the recognised
authorities on the subject assert that the period should
not be less than 30 years.

.Meteorologists in particular, and the people of the
IJritish Isles in general, owe a deep debt of gratitude
to the late Mr. G. J. Symons, F.R.S., for having
commenced the collection of rainfall statistics in i860,
and for publishing the results yearly in the volumes of
British Rainfall. The number of stations at the time
of his death, in 1900, was over 3,400. He not only
collected these statistics, but he also secured uniformity
in the measurement of the rainfall and in the exposure
of the gauges, and he thoroughly checked the accuracy
of the returns sent to him. It is satisfactory to know
that the work is still being carried on under the able
supervision of Dr. H. R. Mill.

I-rom the rainfall maps of the British Isles compiled
by Mr. Symons, Dr. Buchan, and Ur. Mill, it is seen
that the average annual rainfall exceeds 40 inches along
the western coasts, and that in several districts it
exceeds 75 inches, chiefly the west Highlands of Scot-
land, the English Lake District, and the .Snowdonian
District of North Wales. Over the eastern part of
Ireland and of .Scotland, and the south of Kngland, the
rainfall is mostly between 30 and 40 inches, while over
the eastern counties of Kngland it is less than 25 inches.

The average annual rainfall of Kngland is about 32
inches, of Wales 49 inches, of Scotland 47 inches, f)f
Ireland 42 inches, and of the British Isles as a whole
39.5 inches.

At Seathwaite, in Borrowdale, Cumberland, I he-
average annual rainfall reaches the large amount of
'.■?5-49 inches; while about a mile further away on the
shoulder of the hill, near .Stye Head, the average rain-
fall is 175 inches.

The average monthly rainfall at Seathwaite is as
follows : —

January .

15-51 ins.

July..

9 21 in

February .

'2'03 ,,

AURUSl

"•52 ,,

March

'035 ..

September. .

ii-8o ,,

April
■Sia.y

6<» ..

October . .

14-06 ,,

684 ,.

November..

13 82 ..

June

7-49 ..

December . .

15-87 ..

The prevailing winds over the British Isles are mostly
from the south-west. These come off the Atlantic warm
and highly charged with moisture; and as they strike
against the hills in the west, the moisture is condensed
and falls as rain. Thus the heaviest rainfall occurs in

Altitude

100 ft.

200 ,,

300 .,
400 ,,
500 ,.
600 ,.

700 .,

the west, and the amount increases according to alti-
tude.

A few years ago the author discussed the average
rainfall for the 10 years 1881-1890, at 309 stations in
England and Wales, grouping the stations according to
altitude above sea-level. The results for each hundred
feet were as follows : —

Rainfall 2 /-eg ins.
30*50 ..
3I-49 ..
3249 ..
,, 40-64*,,

37-38 „
39-01 ,,

These results show clearly an increase of rainfall with
altitude.

Wishing to confirm the statement already made that
the heaviest rainfall occurs on the west coast, Ike, the
author subdivided the above stations into western and
eastern — considering those as " western " which
drained towards the west, and those as " eastern "
which drained towards the east. The following inter-
esting results were obtained : —

West. East.

Altitude 100 ft. .. Rainfall 3315 ins. 24S2 ins.
200 ,. .. ,. 35 87 ,, 25 94 ,,

300 .. •■ .. 3572 .. 26.89 ..

400 „ 39-56 ,. 2845 ,,

,, 500 .... ,, 46-08* ,, 29H7 ,,
600 .... ,. 38 08 ,, 35S4 ,.
700 41-25 .. 35-27 ..

These values show in a very striking manner that
ihe rainfall is considerably greater in the west than in
the east, the excess being nearly a quarter. If the
stations had been more numerous, and if the observa-
tions had extended over a longer period, there is no
doubt that the results would have been more uniform.

The place which has the heaviest known rainfall in
the world is Cherrapunji, an Indian station situated in
the south-west of Assam, on a small plateau forming
the summit of one of the spurs of the Khasia hills.
The hill on which Cherrapunji is situated rises pre-
cipitously about 4,000 feet from the lowlands of
Cachar and Sylhet, which are barely 100 feet above
sea-level. The south-west monsoon, advancing from
the Bay of Bengal, sweeps over these low lands, and,
meeting the hills, is suddenly deflected upward. Rapid
condensation takes place and heavy rain falls. The
average annual rainfall at Cherr.ipuiiji is about 500
inches, which f.'ill mostly between April and September.
In the month of August, 1841, the rainfall amounted
to 264 inches. The heaviest rainfall in one day was
40.8 inches on June 14th, 1876.

The extremes in this coimtry appear very insignificant
compared with tile amount just named, nevertiiele.ss
thev are often considerable. For instance, on August
6th, 1857, the observer at Scarborough measured gj
inches, but the rainf.ill actually exceeded that amoimt,
as the gauge had overflowed. At Seathwaite 8.03
inches fell on November 12th, 1897. On July 14th,
1875, more than 5 inches fell over Monmouthshire.
On June 23rd, 1878, Mr. .Symons, at Camden .Square,
London, recorded a fall of 3J inches in an hour and a
half.

It is these exceptionally heavy rainfalls whit-h are so
serious and which do such an amount of damage. It
is, therefore, necessary for engineers and surveyors to
know something of the rate at which rain may be

•These values .ire l.-irKcly increased by the heavy rainfall at
I Seathwaite.

Sept., 1905.]

KNOWLEDGE & SCIENTIFIC NJEWS.

--^

expected to fall, in order that they may be able to pro-
vide adequate means for the storm-water being carried
away without causing floods. For this purpose self-
recording rain gauges are of great value. These might
with advantage be also used by other observers with
whom " money is no object."

Fig. 3 is a copy of the trace by the self-recording
rain gauge at the Fernley Observatory, Southport,
which shows the heavy rainfall which occurred on Sep-
tember loth, 1903, during the meeting of the British
Association in that town.

Thunderstorm rains are often very heavy, but are
mostly of a local character; they are also occasionaJIy
accompanied by hail. The hailstones usually take the
form of little pellets or balls, and consist of compacted
ice and snow. During the exceptionally violent
thunderstorms which occurred at Harrogate and at
Richmond, in Yorkshire, on July Sth, 1893, hailstones

and March loth, 1855, some of which are reproduced
in Fig. 4.

Snow is much less dense than rain. A foot of snow
is, rouglily, equal to an inch of rain. Snow, however,
varies greatly in density; with very dense snow, seven
inches may equal one inch of rain, while with very
light snow as much as sixteen inches may equal only
one inch of rain.

A " rainy day " in this countrv is that fin which a
hundredth of an inch (.01 in.) of rain has been
measured. The average number of rainy days in the
year at the Royal Observatory, Greenwich, is 157;
these are distributed over the months as follows : —

January
February
March ...
April ...
May ...
June ...

July ...

August

September

October

November

December

Fernley Observatory. Southport HulUutUs Hum 0,jut/, Record lsM/i,^f>->^^<^/e-// , ._f902>,
S"" )0 II .ii/./i 1 2 :<. ^- i 6 1 b 9 10 II M,4"' 1 -- :r 'V 5 6 7 s 9 nr'

."^

IMO ^
<

%
OTO vl

020 c

■* O30

~~ 020

010

t-ll

9 !

0 1

ouri

F'g- 3- — Record of Heavy Rainfall at Southport, September 10-11, 1903.

from 2 to 3 inches in diameter fell, and caused great
destruction of property. These hailstones had several
alternate coatings of opaque and clear ice. These
coatings were no' doubt due to the re\olutio'ns accom-
plished bv the hailstones, which were probably several
times drawn in towards the vortex of the storm.

Pig. 4.— Snow Crystals, by QIaisher

When the aqueous vapour in the air is condensed at
a temperature below the freezing point it freezes and
falls in the crystalline form of snow. Snow crystals
are six-pointed stars, and are of great variety. The
late Mr. J. Glaisher, F.R.S., observed nearly 200 differ
ent varieties of snow crystals between February Sth

From a long continued series of rainfall records it
is readily seen that there is a considerable variation in
the annual amounts. The London records of rainfall
show that from 1730 to 1750 there was a succession of
dry years, and most of the readers of " Knowledge "
will remember that there was also a succession of dry
years (with three exceptions) from 1883 to 1902. The
periods of successive wet years have been somewhat
shorter than those of dry years.

With regard to the limits of fluctuation in the total
rainfall, Mr. Symons arrived at the following con-
clusions : — I. The wettest year will have a rainfall
nearly half as much again as the average. 2. The
driest year will have one-third less than the average.
3. The driest two consecutive years will each have one-
quarter less than the average. 4. The driest three
consecutive years will each have one-fifth less than the
average.

These conclusions are of the greatest importance to
engineers when considering the question of water sup-
ply, for if provision is not made for " the driest three
consecutive years," the result will most likely be a
"water famine." There are many interesting sub-
jects connected with rainfall, such as the influence of
sunspots, periodicity, cycles of rainfall, &c., but these
have not been discussed, as they are outside the scope
of the present paper.

224

KNOWLEDGE & SCIENTIFIC NEWS.

[Sept., 1905.

Stscr MsLp.— No. 4.

Perseus. Aviriga, and Taurus.

The fxjrtion of the heavens here represented is one full of
interest. In addition to the three well-known constella-
tions named, we have the greater part of Orion, which
forms one of the most conspicuous and easily recognised
of all the constellations, as well as Gemini (the greater
part of which has appeared in Map No. 6).

Orion is one of the useful star figures by which one's
position is readily ascertained. The three stars forming
the head are due north of the centre of the belt. The
sword depending from the belt is an appropriate sign of
the N. and S. line +.

The Great Nebula^ of Orion, situated in the centre of
the sword, is certainly one of the most remarkable objects
in the heavens. This nebula', visible to the naked eye, and
presenting a wonderful appearance on the photographic
plate, seems to be but the centre of a huge spiral which
extends faintly on all sides to the limits of the con-
stellation.

There are a number of conspicuous stars in this part
of the sky.

e Persei (II. h. 37 m. + 48' 49') is a triple star, of
which two, A and B, are probably binaries, while C at a
distance of 80" does not share the same proper motion,
and is, therefore, probably independent.

^ Persei (Algol) (III. h. 2 m. -f- 40° 35'). This star has
long been known as an e.xtraordinary variable, hence
called El Goiil, " the demon." It has a regular period of
variability. After being for 2 days 21 hours of 2-2 mag-
nitude, it rapidly declines, until in just over four hours it
is only yj magnitude, after which it increases again in
about the same time to its original magnitude. It is now
practically certain that this change is caused by the in-
terposition of a large dark body revolving around the
brighter one, the orbit of w-hich happens to be in a plane
which passes through our earth. The two stars are
probably very close together, and of much the same size.
On September 3 it is at its minimum at 4 h. 42 m. a.m.,
from which time the other phases can be calculated.

The Pleiades {Wl.h. ^1 m. + 23^48'). This well-known
cluster contains si.x stars visible to the naked eye. As
most of them have a common proper motion, they doubt-
less form a system. A nebulosity surrounds all the prin-
cipal stars. The length from Atlas to Celano is 1 ' 6'.
Those who have not considered the matter are ofien sur-
prised to hear that this little group covers an apparent
area much greater than that of the I'ull Moon (the mean
diameter of which is 31'), and a representation to scale is
therefore appended.

o Tauri (Aldebaran) (I\'. h. 30 m. + ifp 19'). Magni-
tude, ri. Near this is the group known as the
" Hyades."

On Jreptember 19 the Moon will pass across the region
of the Hyades and Aldebaran. (Vide p. 236.)

a Auriga {Capella) {\ . h. 9 m. + 45^54'). Magnitude,
02.

ft Orionis {Rigel) (V. h. 10 m. — 8*^ 19'). Magnitude,
0-3.

Nebula M. 1. Tauri (V. h. 29 m. + ai'-' 57'). Known
as the " Crab."

0 Orionis (V. h. 29 m. — 5'' aS*). A multiple star situ-
ated in the Great Nebula of Orion. Four principal stars
are of magnitudes 6, 7, 7J, and 8.

a Ononis (V. h. 34 m. — 2° yj). A multiple, com-
poied of two sets of treble stars.

{ Orionis (V. h. 36 m. — 2^ o'). A double star, magni-

tudes 2 and 6, with a faint companion 57" distant of loth
magnitude.

a Orionis (Belelgiiese) (W h. 50 m. -f 7° 23'). A yel-
lowish-red star, 1st magnitude. \'ariable to a slight
extent.

^Auriga {Menkalinan) (V. h. 52 m. + 44° 56'). A
spectroscopic binary, proving it to consist of two equally
bright stars revolving in a period of 4 days.

The

Great Sovith Tropical
Spot on Jupiter.

One of the most interesting and prominent features
of Jupiter during the last four years has been a dark
shading spreading more or less over the south tropical
zone. It has been visible since the spring of 1901, and
has maintained so striking an aspect, albeit a change-
able one, that it promises to offer a parallel with the
red spot and its surroundings as regards permanency.

Though situated in the south tropical zone of the
planet its motion accords with that of the south tem-
perate current which is about 9 h. 55 m. 19 s. from a
mean of many spots seen at Bristol in recent years.

Between June 18th, 1901, and August 7th, 1905, the
spot completed 3,655 rotations, with a mean period
of 9 h. 55 m. 18.9 s., and it lost 16°. 2 of longitude
per month relatively to system II. (based on a rate of
9 h. 55 m. 40.63 s.) of Crommt'lin's cphemeride-s.
The motion appears to have become gradually slower
with the time, the rotation period having been about
9 h. 55 m. 18.5 s. in 1901, whereas it was about
9 h. 5.S m- 19-55. in 1905.

In 1903 the average length of the spot was 48°, but
when passing the red spot in July, 1902, it was about
87° long. I obtained an observation of the object on
August 7th, 1905, as under : —

u. M. Longitude.

P. end on CM.

•• '5 53

157-9

Middle

16 28

179 I

F. end

.. 17 5

2014

.So the length on that occasion was=4j'^.5. I used
a i2i-in. Calver reflector, powers 300 and 440, but the
latter was rather too high for the state of the air.

The durablcness of this marking, its conspicuous ap-
pearance, and the fact that it has apparently influenced
the very irregular motion of the rod spot in and since
1901, render it a peculiarly important and attractive
object for telescopic observers. It should be looked for
in the following' longitudes duriiii,"- tlie next two years : —

Date.

1905. September 15

October 15

,, November 15

December 15

igo6. January 15

Fel)ruary 15

April 15

August 15

,, October 15

December 15

igoy. February 15

April 15

,, September 15

Bristol, August 8, 1905.

Longitude.

158K

142-6

1264

iro-2

940

778

454

340-6

. . 308 2

.. 2758

243'4

2 1 I 'O

1300

W. I'. Denni.nc.

Supplement to "Knowledge & Scientific News," September, 1905.

MAP No. 4.

MAP I

-(NovthPola r Region )

BRIGHTNESS

I St Mag.

2nd

ard

4th

Sth

6th

Variable

Nebula.

MAP No. 4.

Perseus, Auriga, and Taurus.

55C
The Pleiades.

Skpt., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

SesLweeds

A HolidaLy Pa-per for Field
BotaLiiists.

By David W. Bevan, Scarborough F.N. Society.

II. -The Red Seaw^eeds.

If the brown seaweeds are the g-iants of the shore, the
red are the fairies. These httle plants show an almost
endless variety of form, but they are all really very
much alike in build. Like all other lowly plants, the
seaweeds are built up entirely of cells, and it is simply
the grouping- of these cells, and their way of dividing,

Fig. 1. Fig. 2.

that determine the shape and appearance of the red
seaweeds.

We have only time to glance at a few of those that
are pretty sure to^ turn up. One of the loveliest little
things for the microscope is CalUthamnion rosetim (Fig.
I — a). It is unfortunate that these little beauties have no
"common" name. Tlie botanical name means, in plain
English, " The bonny bush of rosy hue." It is a
simple row of oblong cells, with branches of the same
pattern coming off right and left alternately, each cell
of the branch again bearing a branch : — a bonny little
plant, only about half an inch high, at most, growing
often on the bare rock. Each cell contains a number
of round, red bodies, corresponding to- the chlorophyll

corpuscles of the land plants. Similarly, the brown
seaweeds are brown because their colour-bodies are
brown. But they all contain chlorophyll. Put bits of
a red and a brown seaweed in alcohol for a few
minutes ; these colours are dissolved out, and the sur-
prising fact appears that the brown seaweeds, and the
red, are as green as grass.

Another CalUthamnion {floridulum) entangles mud
and sand in its branches, forming dense, dark red
cushions up to two inches in thickness. As you wend
your way over these cushions, you would scarcely
suspect you were treading on a plant. On tearing the
cushion open, we find the plant is dead below, but ever
growing at the top — like the bog moss.

The most delicate seaweed known to the writer, and
a pretty object for the microscope, is Baiigia, a single,

unbranched filament of extreme delicacy. It grows in
the most reposed situations that are daily hammered by
the waves. How it survives — and winter is its most
flourishing time — is a mystery. Though it begins life
as a single row of cells, a transverse section taken at
maturity w'ould pass through four cells, and these
divide again to produce spores. Fig. 4 is a highly
magnified view of a portion of a filament, the outlines
only of the cells being shown.

The Folysiphonias (Fig. 2), with their long cells
arranged like the staves of a barrel, and the Ceraniiums,
with their pretty forked and often curved tips, are
very common ; and they are all very beautiful under
the microscope.

Fig. S.

Fig. 6.

The commonest i-'olysiphonia, and one which is sure
to be met with, grows in bushy tassels on the Knotted
WVack and it is as pretty as any of them. Tliey all
divide dichotomously, and can be recognised by the
lens, as each "internode" of the filament has one large,
central cell, and a number (varying in different species)
of long, narrow red cells, arranged round it (see Fig.

Fig. 7.

Fig. 8.

^ — a, which is a part of Fig. 2 — a, more highly magni-
fied). The Ceramiums are also dichotomous, and have,
as a rule, curled tips. The naked eye shows they are
made up of alternate light and dark coloured seg-
ments. While all are charming, words fail to describe
the exquisite beauty of the Bristly Ceramium (C. cilia-
turn), when a small snipping is examined under either
low or high power (Fig. 5 — a). It grows at Scarborough
on the front face of the limestone platform of the
White Nab — a tiny plant only about one-third of an
inch high — along with a little Polysiphonia with only
four "staves" toi its "barrel." This little Ceramium is
easily known by its strongly-incurved tips, and by the
colourless hairs growing on its frond. One's first
impulse, on seeing this little beauty, is to call one's
friends and neighbours together to share one's joy.

225

KNOWLEDGE c^ SCIEXTIEIC NEWS.

[Sept., 1905.

Fig. 5 — b is a view of the very tip of a Ceramium frond,
showinir the regular method of cell division.

Other red seaweed.s show their beauty without the
aid of the microscope, .\mong them are the Pttlota.
a splendid feathery plant, growing on stalks of the big
Tangles, and the Mermaid'.s Comb (Plccamiiim),
happiest below low-water mark, and easily recognised,
because the frond bears branches on one side only,
like the teeth of a comb, and these repeat the process.
Fig. I ! shows a .snipping of the frond enlarged. Others
are Chilocladia, with sprays like branching rows of
eggs, or beads, CoraJlines, with a white skeleton of
carbonate of lime— formerly believed to be an animal
allied to the corals— and the broad, leafy forms in great
variety, from I'orphyra, a flat sheet of cells, several
inches across, lying flat and black on the rocks when
the tide is out'; Irish Moss (Chondrus), with a flat
dichotomous frond, often rather curly ; and a host of

others, till we reach the Rhodymenias, with frond of
various patterns, and the Delesserias, with leaves ex-
actly like those of land plants— midrib, veins, and all
complete. Fig. 6 is part of a frond of R. laciniata,
natural size ; Fig. 7 is R. palmate, half size, and Fig. 8
is D. sanguinea, natural size.

The Irish Moss is one of the few seaweeds that are
put to any use. It is still gathered, wa.shed in Iresh
water, and dried, and in this state .sold by the chemist
for making jelly. The reader with a turn for experi-
ment will be able to test its "virtues" for himself.
We must not omit to mention, however, that the
WTacks are also useful to man. They are still largely

used for making washing soda. The dried wrack is
burnt, and the a.sh (known as " kelp'") is thrown into
water, when the s<Kla dissolves, and can be easily
crystallised out. (.Another ea.sy experiment for the
enthusiast, best not performed in your seaside lodgings,
as the special perfume produced in the burning d<x:s
not commend itself to many.)

Burning reminds us of drying, and drying reminds
us that the visitor to the seaside may wish to take dried
specimens home. There arc two difficulties to sur-
mount in drying seaweed. The first is the salt in them,
which is got rid of by a good soaking in fres/i water.
'I"he second is the gelatinous nature of the frond of

many of them, which causes them to stick to the drying
paper. To prevent this, put between the seaweed and
the paper a clean linen rag — old handkerchiefs are as
good as anything else for the purpose. The stickiness
of so many seaweeds can. however, be made use of, for
if vou take the paper on which j'ou intend to finally
mount the plajit, and slip it into the lx)wl of water
under the seaweed, }ou can then gently raise the paper
with one hand, and with the other spread out the whole
plant as it floats upon the paper. The most delicate
plants can be easily mounted in this way. ' Now cover
with rag and dry Ix-twcen drying papers. 'Ilie plant
will adhere firmly to its mount, while the linen prevents
it adhering to the drying paper.

In searching for red seaweeds, it is well to look out
for fruiting specimens. The process by which the egg
cells are fertilised in the red seaweeds is very much
more difficult to follow than in the brown seaweeds,
but the result — the fruit — can, in many cases, be seen
with the naked eye. It is sure to be found in summer
on some of the Ceramiums (I'ig. 5 — c) and Poly-
siphonias, and when it is found on that fine plant Ptilota
(a plant growing on the stalks of Tangles), it forms a
very fine microscopic object. Fig. 2 — c is a snipping
of Polysiphonia with the male organs (antheridia).

The red seaweeds, however, have two strings to
their bow. Tliey produce not only fruit, by the union
of male and female elements, but spores, without the
need of such union. These ahvay.s come in groups of
four, and are hence called tdrasporcs. When these
tiny spores are set free, they develop into new plants.
.Some plants have them outside, either sessile or grow-
ing on short stalks, while others have them inside,
buried in the frond. They are easily seen with a Ions,
and better with the micro.scope. Callithamnion (the
' bonny bush " mentioned above) is a beautiful object
when it bears si)ores (Fig. 1 — /;, i). .So is Nitophylhini,
a pretty common plant with a broad flat frond. It
shows on its surface distinct spots where the buried
tetraspores occur. . . . (Fig. 9). A spore-bcaiing
tuft of Rhodomela, about ,i, inch long, is shown en-
larged in I'ig. 3 — b ; and a small portion of it is again
magnified in Fig. 10 — h, where the dark spots are seen
to be groups of spores, four in a group, but only three
visible. These figures may be compared will) those of
Polysiplionta (Figs. 2 — b and 10 — a), in the last ol
which one of the barrel-shaped segments has burst and
discharged the spores. I""ig. 5 — d is a bit of a
Ceramium frond with tetraspores.

The red seaweeds appeal to the most cursory wan-
derer on the rocks, f)n account of their numerous and
varied forms, and their obvious beauty. But the
fortunate possessor of a microscope will soon find a
wealth of liidden l>cauty in them which will much more
than fulfil any expectations which this short article may
have aroused.

It remains to say a few words about the Green .Sea-
weeds, which have charms all their own. and these will
form the subject r>f the third ;incl last article.

The Word "Patent"

With reference to a letter appearing in our July luimlier,
" W." writes to ask if the word " I'atcnt " is not merely a conden-
sation of " Pattern entered." It is uat, IxiiiK derived from the
Latin pateo, "to open," Letters patent being " opon to the
perusal of all." I'attern is derived from tin; I'rcncli /■a/co;/,
an original model to be copied.

Sf.pt.. 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

227

ASTR.ONOMICAL.

Charles P. Butler, A.R.C.Sc. (Lond.), F.R.P.S.

Star Streams.

The Times correspondent with the British Association tele-
graphs from Cape Town on Angust 17th: — "In the mathe-
matical section the most important contribntion was made by
Professor Kapteyn, Director of the Astronomical Laboratory
of the L'niversity of Groningen, Holland, who read a paper
entitled ' On Star Streaming.' Professor Kapteyn explained
that he had been working for many years in making investiga-
tions into the structure of the stellar universe, and he had
arrived at the remarkable conclusion that the proper motions
of the stars are not distributed at random in space, but that a
great part of the brighter stars belong to one or other of two
great streams of stars moving in the plane of the Milky Way
and meeting one another in space. This discovery opened up
so many questions of the greatest interest that he had asked
some of the most important observatories in the world to
co-operate in several lines of research which must be carried
through before the problem could be completely solved. Pro-
fessor Kapteyn stated that he required in particular the deter-
mination by the spectroscope of the motion in line of sight of
a great number of stars down to the eighth magnitude, and he
hoped that the Royal Observatory would furnish him with
much precious material of this kind."

Algol VaLriaLbles.

On the iSth he reports : " In the Mathematical Section
something of the nature of a sensation was created by a
remarkable paper by Mr. Jeans, of Trinity College, Cambridge,
on the theory of argol (? Algol) variables, which excited the
enthusiastic interest of Professor Darwin, Sir David Gill, and
other astronomers.

Recent Observa.tlons of Jupiter's Sixth
Satellite.

In a telegraphic despatch from the Lick Observatory it is
stated that Professor Albrecht has observed the new sixth
satellite of Jupiter with the Crossley reflector, the following
being the determined positions: —

G.M.T.

Position Angle.

Dis'ance.

1905 —July 25-95
.. 2697
.. 27-93

55°o
52°-7
50°-7

25-1
24'-3
23'-6

The North Pola-r Cap of Ma.rs.

From November, 1904, to May, 1905, Mr. Lampland was
successful in obtaining a big series of determinations of the
various features of the north polar cap of Mars. In a sum-
mary of the results tabulated, he gives the various aspects pre-
sented on various dates during the above period. On Janu-
ary 13, 1905, the cap was shrouded by an extensive veil of dull
white ; this was eventually pierced by the cap, showing as a
brilliant spot about 4^ in diameter, and then as a contoured
patch some g'^'j across. The veil was of the same nature as
had been obscuring the cap since October 30, and appeared
to consist of haze or cloud. From this time onwards many
measures of the diameter of the polar cap are given.

On January ig, subsidiary snow patches began to appear
from under the veil.

During April no signs of the surrounding white collar were
visible, and from a close study of the epochs of its appearance

and disappearance, it is thought that it may be something like
a spring mist, surrounding the cap during the hotter months
of its melting, and this view is supported by the feature of its
indefinite boundary. The snow cap proper is girdled during
its contraction by a blue belt, due undoubtedly to the material
formed by its melting, which can be none other than water
from among all the substances we know, whilst the collar lost
itself unedged in the surrounding ochre, thus exhibiting the
indefiniteness of cloud.

When the white collar disappeared, subsidiary outlying snow
patches stood revealed, flanking the true cap about. Of these,
the first to show was the great patch in longitude 206". This
was first seen by Schiaparelli in 1888; it was independently
discovered at Flagstaff in 1901, and re-observed there in 1903
and 1905.

In 1905, the next most prominent subsidiary patch lay in
longitude +'^10, just east of the Mare Acidalium, and a third
set was found in about longitude 311'.

Proposed Ma-gnetic Survey of the North
Pacific Ocean.

The rapid development of commercial activity in the Pacific
region during recent years has rendered necessary the institu-
tion of a definite scheme for determining more reliable values
of the magnetic elements for those navigating these waters.
Except for data from occasional special expeditions, and such
as were acquired in wooden vessels many years ago, the pre-
sent magnetic charts in use depend largely upon observations
made on islands and along the coasts. It is evident, however,
that such determinations are rarely representative of the true
values on account of prevalent local disturbances.

The present plan is to be started under the patronage of the
Carnegie Institution, from which an initial allotment of ^^5000
has been obtained to cover expenses during 1905. The scheme
provides for the chartering of a wood-built, non-magnetic
sailing vessel of about 600 tons, which, after starting from San
Francisco, will pursue a clockwise spiral course, embracing
the entire North Pacific Ocean. The total length of the pro-
posed cruise is about 70,000 knots, and it is estimated that the
work will occupy about three years.

It is fortunate that the region under consideration contains
magnetic observatories in suflicient number and proper dis-
tribution for furnishing the necessary corrections to be applied
to the observed magnetic elements in order to reduce them to
a common epoch. For this purpose, continuous records of the
magnetic variations will be available from Sitka (Alaska),
Mexico, Honolulu (Hawaiian Islands), Manila (Philippines),
Shanghai (China), Tokio (Japan). In addition, it is hoped
that a station will soon be started in California, and that the
German Government will continue its magnetic observatory
at Apia throughout the period of the survey.

Monochromatic Photographs of the Orion
Nebula.

Professor J. Hartmann, in the course of a series of experi-
mental trials of a small quartz spectrograph, has recently ob-
tained photographs of the Orion nebula, which show important
differences in the composition of its several parts, indicating
that different parts of the nebula emit light of difterent com-
position, and that extensive areas of characteristic form shine
almost solely with ultra violet light of wave-lengths 3727.

With this small camera the images are, of course, small ;
I mm. on the plate corresponds to an angle of about 10', but
this was found quite sufficient to permit the recognition of the
various parts of the nebulous areas. It was found advisable,
however, to be able to utilise apparatus of higher power, and
this was done by the use of suitably stained colour screens.
The most useful of these are : (i) Pici-ic acid, which transmits
the longer wave-length, especially the nebular lines Ni, N.,, and
H(3, and absorbs all wave-lengths shorter than 4800 ; (2)
(Juininc cobalt, which transmits only the rays between 3880 and
3740; (3) iV!<roso_/i/(f;-, the absorption of which begins at 5050,
but dies oft" again near 4000, and 3727 is easily transmitted.
By suitable combinations of these, photographs have been ob-
tained with a Steinheil mirror of 24 cm. aperture and 90 cm.
focus.

The chief result is the remarkable intensity of the 3727
radiation in all parts of the nebula.

KNOWLEDGE c^- SCIENTIFIC NEWS.

[Sept., 1905.

CHEMICAL.

By C. .■\iNS\voKTn Mitchell. H.A. (0.\on.), F.I.C.

On Antimony in R.\jbber Rings.

A r.AKAGKAi'H with the sensational heading •• Poison in
Stoppers " appeared recently in one of the daily papers, and
purported to be an interview with a Liverpool doctor. This
gentleman was reported to have examined the red rubber
rings so largely used for the stoppers of mineral water bottles,
and to have asserted that a poisonous dose of antimony could
be removed from them by a simple washing with cold water.
In fact he is stated to have attributed many deaths within his
own experience to this cause. .\s such stoppers have been in
use for over 30 years, and are now almost universally em-
ployed, the question is one of the greatest importance, and the
present writer has therefore made experiments to determine
the degree of truth in the charges here brought against them.
These red rings certainly contain a large proportion of anti-
mony in the form of the pentasulphide, and it is to this that
they owe their colour. O'lantitative determinations showed
that the proportion of this pigment in the rubber amounted to
15 per cent, or more. Experiments were next made to dis-
cover to what extent this antimony was soluble. The rings
were boiled for over an hour with water, but absolutely no
trace of antimony could be detected in the liquid. .As it
seemed possible that in practice the rubber of the rings might
become worn and fragments fall into the bottle and so be in-
advertently swallowed, parallel experiments were made with
hydrochloric acid of 10 per cent, strength, i.e., much stronger
than the acidity of the gastric juice ; but in this case, too, the
liquid was quite free from antimony. This is not surprising,
since it is well known that antimony pentasulphide is only
soluble in alkalies and concentrated acids ; and hence it would
seem that there must be some error in the report about the
stoppers examined in Liverpool. .-Xt the same time it would
be advisable for the manufacturers of the rings to replace
antimony sulphide by some pigment above suspicion. For
although as at present employed the rubber-ringed stoppers
may be regarded as quite safe, there are conceivable cases in
which the antimony might be brought in solution — t'.^., by con-
tact with strong potash. The effects of antimony upon the
system are ver>' similar to those of arsenic. Both are irritant
poisons, and both are cumulative in their action. It is well
known that the dead bodies of the Styrian arsenic eaters
remain undecomposed for years, and this preservative effect
is also a characteristic of antimony.

The Formation of Radium from Uranium.

A very interesting discovery made by Mr. F. Soddy fur-
nishes new evidence in support of the now generally accepted
view that one element can, under certain conditions, be trans-
formed mto another. A solution containing over 2 lbs. of
uranium nitrate was freed from all radium that it contained
by repeated precipitation, and was then kept for 18 months in
a closed bottle. It was examined from time to time, and it
was found that it gradually acquired the power of emitting an
emanation absolutely identical in characteristics with that given
off by radium. Hence the conclusion was arrived at that the
uranium was very gradually transformed into radium, though
only traces of the latter substance were present in the solution
at the end of the period of observation.

Thorianite : A New Mineral from Ceylon.

( )n<: of the most valuable minerals known has recently been
examined by Professor I )unstan and .\Ir. Blake at the Imperial
Institute. It is found in the form of small dark cubical
crystals in gem-bearing deposits in rivers in Ceylon; the
principal source being the bed of the small stream, Kuda
Pandioya, but it is not known from what kind of rock the
deposit is derived. The mineral varies in colour from dull
grey to dark brownish-black, and many of the crystals have a
polished appearance from having been worn in the bed of the
river. It is nearly opaque, except in very thin layers, is very^
infusible, and becomes strongly incandescent when heated to '
a high temperature. Its- density is about 97. It can be:

readil)' powdered, and dissolves easily in dilute sulphuric
acid, yielding a gas which consists mainly of helium. It is
composed principally of thoria (thorium dioxide), the amount
of which ranges from about 70 to So percent. It also contains
from 10 to 12 per cent, of uranium oxide and rare earths, and
smaller amounts of oxides of lead and iron. One specimen
was found to contain 0-39 per cent, of helium. The com-
mercial value of thorianite is due to the free thoria, which is

Action of Thorianite on a Piiotographtc Plutc In tlic Dark.

used in the manufacture of mantles for incandescent gas
burners. Hitherto the chief source of this oxide has been
monazite sand, which contains only a small percentage of
thoria. Consignments of the new mineral from Ceylon have
been sold in this country for as much as ^Tisoo per ton.
Kadium has been identified in thorianite, which is one of the
most radio-active substances known, though it is not quite so
active as some of the pitchblendes examined by NIadame

RadioKrapli of a .sliillinK lukcn tlirouKli I'uper by meani uf Tflorianitc.

Curie. The present writer has had the opportunity of examin-
ing a number of specimens of thorianite and testing their
radio-activity, and some of the results are shown m the
accompanying figures. In the first case the thorianite was
sprinkled over the photographic plate and left for 12 hours in
the dark, and in the second experiment a shilling was placed
on the plate and covered with paper, on which the mineral
was scattered. It is interesting to note that the radiations
must have been reflected beneath the coin in such a way as to
obtain an image of the device.

Sept., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

229

ORNITHOLOGICAL.

By W. P. Pycraft, A.L.S., F.Z.S., M.B.O.U., &c.

The Slaughter of Ravens and
Peregrines,

The Field (July 29) contains a short account of the ruthless
persecution meted out to Ravens and Peregrines in Arg\'Ie-
shire, which is anything but pleasant reading. Though we
fully realise that these birds, if too numerous, are a menace to
farmers and game preservers, there can be no doubt but that
anything like a war of extermination is not only unjustifiable,
but foolish. The determination and ruthlessness shown by
the stalker on the occasion described by the writer are worthy
of a better cause ; and we are glad to note that he, too, con-
siders the incident regrettable. •' Surely," he remarks. " such
persecution as that of the raven and falcons might well be
stopped, at all events, in the breeding season. The sight of a
falcon on the wing is to many sportsmen a real pleasure, and,
in mv opinion, a few grouse might well be spared to them."

Nesting of the Egyptian Plover.

The remarkable nesting habits of the Egyptian Plover,
Pluviuins (B^yptius, have given rise to considerable discussion
during the last twenty years or so. The Field (August 5)
contains an interesting note on this subject, which may be
regarded as finally clearing up the matter. Brehm, it may be
remembered, stated that this bird buried its eggs in the sand,
where they were hatched, while Dr. Yon Heuglin, on the other
hand, said that he had always found them uncovered. From
careful observations of Mr. A. L. Butler, it would seem that
Brehm was right. His attention was drawn to the subject by
the apparently aimless wanderings of a pair of these birds on
a sand-bank on the Rahad River. At last one sat down, and
remained seated for nearly an hour. Flushing the bird he
endeavoured unsuccessfully to find the eggs. The next day
the bird came and sat on the same spot, and a second search
revealed two eggs about an inch under the sand. This was at
noon, and the sand was burning hot, hence he concluded that
the bird visited the eggs at about this time to shield them from
this excess of heat, the incubation being performed by the
heat of the ground.

Hemipodes Breeding in Confinement.

The value of the work done by the " aviculturist," is slowly
beginning to obtain recognition, and no one has done more to
bring about this change of opinion than Mr. D. Seth-Smith,
who has attained a series of quite remarkable successes in
inducing rare tvpes to breed in captivity. After much care
and trouble his endeavours to breed the variegated bustard
quail [Titrnix varia) have been rewarded, and he is to be con-
gratulated, for many new facts concerning the habits of these
birdsat this time have come tolight. In the Augustnumberof the
Avicultural Mai^azine he gives a long and extremely interesting
account of his observations. It has long been known that
among Turnices the females are the more brilliantly coloured,
and that as is the rule in such cases the male undertakes the
work of incubation, while the female does the courting. How
this is psrformed is particularly well told by Mr. Seth-Smith in
the article referred to. '' The male," he writes, " squats among
the grass, and the female runs round him. . . . with tail
more or less erect, and crop extended and carried close to the
ground. Having run round him once or twice she stands
facing him at a distance of about a foot. . . . and com-
mences ' booming ' or ' cooing ' to him like a cock pigeon, at
the same time stamping and scratching with her feet, while the
male responds with a faint clucking noise." Like the Tina-
mous, Mr. Seth-Smith believes these birds are polyandrous.

A White Swallo>v.

Mr. Henry Taylor records in the Field (August 12) the
fact that a white swallow is daily to be seen at his house at
Dyson's Wood, near Caversham. When it first appeared it
would seem that the swallows of the neighbourhood en-
deavoured to drive it away, but they have now apparently
grown used to its presence, and in no way molest it.

Dartford Warbler Breeding in Sussex.

The /ooloi^ist for August records the breeding of the Dart-
ford warbler at Maresfield, in Sussex, in May last, and the
birds appear to have been successful in rearing their young.

Albino Starling.

The Rev. Julian Tuck records the fact than an albino star-
ling was fhot at Beyton, in Suffolk, in June last. It had
apparently only recently left the nest.

Dotterel in Rutland.

The Field (June 3) records the occurrence, at Ridlington, of
seven Dotterel. Eitdronias ntinnelhis, which were kept under
observation in a field for halfanhour. " Mr. Horn," says the
writer, "previously saw the same number at Moscott on
May 21.

PHYSICAL.

By Alfred W. Porter, B.Sc.

Professor Rutherford has been making further deter-
minations in connection with the particles emitted by radium.
Some of his results may be chronicled here. He finds that the
total number of .'\lpha particles expelled per second from one
gramme of radium bromide at its minimum activity is 3-6 X 10'" ;
and assuming that the composition of the compound employed
is Ra Br.>. it follows that the total number of Alpha particles
expelled per second from one gramme of rrTi/i»)» at its minimum
activity is 6'2 X 10'". Now the Alpha ray activity of radium
in radioactive equilibrium is four times this minimum value,
and includes three products — viz., the emanation, radium
A and radium C — which emit Alpha rays. Hence he con-
cludes that the total number of .^Ipha particles expelled per
second from one gramme of radium in radioactiveequilibrium is
about 2-5 X 10". This result is deduced from ihe current
produced in a nearly perfect vacuum when all electrons (which
carry a negative charge) were bent aside by a magnetic field.
The close agreement between this value and the value pre-
viously obtained from direct data based on the heating effect
of radium, and the observed volume of the emanation, leaves
now no room for doubt that the Alpha particles carry a positive
chargeatthemoment of their expulsion from the film of radium
salt, though at one time he was inclined to doubt that they
do. Accepting this conclusion, there is no obvious reason for
supposing that they are not charged at the moment of their
expulsion from the radium atoms themselves ; for it should
be noted that the film of radium bromide employed was very
thin.

He has also determined that the number of Beta particles
expelled from one gramme of radium per second is about
7-3 X 10'° which is only a little in excess of the number pre-
viously obtained for radium at its minimum activity. The
results indicate that four Alpha particles are expelled from
radium in radioactive equilibrium for each Beta particle, and
thus confirm the theory of successive changes which Ruther-
ford has done so much to develop.

If it be assumed that only one Alpha particle is expelled
during the disintegration of the radium atom then it follows
that the number of atoms which break up per gramme per year
is i'95 X 10"'. Taking the atomic weight of radium as 225, it
follows that about half a milligramme per gramme disintegrates
per year. It therefore takes about 1380 years for half the
radium present to be transformed.

The Pendulum Accelerometer.

Mr. F. W. Lanchester has devised an interesting apparatus
for measuring accelerations directly. It is clear that this might
be done by mounting on the moving object (e.i;., train or
motor-car) a spring balance, the mass being mounted so
as to permit of its horizontal motion only. The acceleration
of the mass (and therefore of the train) would be directly

230

KNOWLEDGE & SCIENTIFIC NEWS.

[Sept., 1905.

proportional to the extension o{ the spring. Mr. Lanchester

prefers the easier method of arranging the mass as the bob of
a pendulum. This pendulum becomes deflected whenever
the point of support receives an acceleration, and from the
angle of deflection the acceleration is determined ; in fact, the
horizontal acceleration bears to that of gravitj- a ratio equal to
the tangent of the deflection. The first instrument of this kind
was made by him in 18S9. In the 1904 model an improvement
has been effected in the mode of automatically recordinsr the
acceleration. Since this quantity is proportional to the tangent
of the deflection, the recording pencil must be so arranged as
to move equal distances for equal increments of deflection.
This result is attained by pivotting the pencil arm to the
pendulum continuation in such a manner that the point of the
pencil lies always in the plane of the pendulum axis. It is
assumed in the theor>' of the instrument that the motion of the
pendulum bob is substantially that of the rest of the vehicle,
and consequently its motion of swing should be negligible in
comparison with the motion of the vehicle. Its time of swing
must also be kept small compared with the time of change of
acceleration which it is required to record. This necessitates
the use of a ver>' short pendulum, which in the later model is
reduced to 1:5 inches. .An oil dash pot is employed to make
the movements deadbeat. A characteristic feature of
diagrams taken by means of this instrument is the sud-
denness of the drop at the instant of stopping. This re-
presents the jerk nearly always experienced just as a train
comes to rest. A jerk consists in fact of a very sudden change
in acceleration, and not of a large acceleration. Mr. Lan-
chester suggests that the term " jerk " might be given a
scientific meaning by defining if as the rate of change of
acceleration. To prevent this jerk the brake of a vehicle
should be taken nearly off before completely stopping. For
further information the reader is referred to the Pliilcsophical
Magazine for .-\ugust.

The Methods of Physics.

In mathematical physics we employ two kinds of theories,
which may both lead to an understanding to a certain extent
of what goes on in the material world, and which are neverthe-
less very different in their nature and in the aims which they
declare. In the theories of the first kind, it is sought to pene-
trate the intimate mechanism of phenomena; we endeavour
to represent the motion of molecules and atoms, and, as one
must now add, also of ions and electrons; we determine their
velocities and dimensions, the masses and electric charges of
these extremely small particles. All this is foreign to theories
of the second kind. Physicists who prefer these concern
themselves only with magnitudes which are accessible directly
to our observations, such as temperatures, quantities of heat,
electric currents, &c. After having measured these magni-
tudes they establish their mutual relations, and show that
these relations are in accordance with certain general prin-
ciples, amongst which the law of the conservation of energy
and the second law of thermodynamics are the most impor-
tant.^— H. A. Loreniz, La Thermodynamique et les theories
cineliqncs {Journal de Pliysii/iif, August, 1905).

ZOOLOGICAL.

P.y K. LVDEKKFIR.

The Lower Jaw of Manrimals.

Hitherto it has been generally supposed that the lower
jaw of mammals differs fundamentally from that of birds and
reptiles in that each lateral half is formed of a single piece,
instead of comprising a number of distinct elements. Accord-
ing, however, to recent investigations on the jaws of embryos
undertaken by Professor Carl von Bardeleben, this is a
mistaken idea, and in the young condition the mammalian
jaw shows the same compound structure as that of a bird or
a reptile. The mammalian jaw is indeed now stated to be
strictly comparable in every detail with that of a reptile.

Mammal or Reptile?

.\ fossil skull from the Karoo system of South Africa
described in 1884 by Sir R. Owen as that of a mammal, under
the name of Triiy Union longtti'tis, was subsequently assigned
by Professor H. G. Seeley to the reptilian class. Recently
Dr. R. Broom, in the Transactions of the South African
Philosophical Society, has again pronounced in favour of
the mammalian nature of the fossil. Taking all points into
consideration, the author believes Tritylodon to be a mammal,
whose nearest affinities are with the egg-laying duckbill and
spiny anteaters of Australasia, which are evidently specialised
survivors of a once abundant primitive group. Perhaps the
real truth is that the South African fossil presents so many
resemblances to manunals on the one hand and to reptiles on
the other, that it can scarcely be assigned to either group,
but rather forms a connecting link between the two.

A British Armoured Dinosaur.

Not long aj,'!! reference was madr to recent investigations
into the structure of the small dinosaur from the Wealden of
the Isle of Wight, known as IlypsilopluHlim fo.xi. The same
energetic investigator, I5aron Francis Nopcsa, has published
in the June number of the Geoloj^ical Magazine an account of
another dinosaurian reptile, Polacanllnis fo.xi. from the same
locality and formation. The restoration shows a long-bodied
reptile of about three feet in height at the shoulder, with the
hind-quarters invested in a solid bony shield, and the upper
surface of the rest of the body, the neck, and the tail pro-
tected by a double row of large bony plates standing
vertically. The creature may in fact be regarded as a kind
of reptilian armadillo. It may be mentioned that the author
takes no notice of the fact that the name Polacanthiis is pre-
occupied by the designation applied to the paradise-fish
iPolyacuntJiiis).

R.eptlles from North Greenland.

As aflbrding additional confirmation to the idea that the
Arctic regions once enjoyed a genial climate, considerable
interest attaches to the description by Dr. V.. Fraas, in
Midiidchcr om Gyonlands, of reptilian remains from the Jurassic
strata of Northern (ireenland. The first of these is the foot-
print of a land dinosaur, while the second is a vertebra of one
of the ichthyosaurs, or fish-lizards. It seems, therefore, that
in Jurassic times the polar ocean was entirely Tree from ice.

An Extinct Sea-Lion.

Very little is known as to the past history of the sea-lions
and sea-bears (fur-seals), and it is, therefore, a matter for
congratulation that a fine skull has been obtained recently
from the Miocene strata of ( )regon. Mr. F. W. True, who has
described the specimen, states that it is considerably larger
than any existing sea-lion skull that has come under his notice,
its basal length when entire being probably about twenty
inches. The new name, Pontolian nuignns, is proposed for the
fossil sea-lion, as the characters of the skull and teeth do not
agree precisely with those of any living member of the group.
It should be mentioned, however, that if all the modern eared
seals are included in the single genus Olaria, as is still the
practice with some zoologists, there would apparently be no
reason to exclude the fossil species.

The Black Sea Porpoise.

According to the well-known student of the Cctacea,
Dr. O. Abel, the porpoise of the HIack Sea is quite distinct
from the common porpoise of the Atlantic (Plioc/inn com-
ninnin), the < hief difference being apparently the form of the
head. PDr this species the name Phocana rrlicin is proposed.
Seeing that the common porpoise does not enter the Mediter-
ranean, it is only natural to expect that its Fuxine representa-
tive .should be distinct. Dr. Abel considers that the reason
why porpoises do not enter the Mediterranean is because the
water is too salt for them. In the same comnnmication he
describes a fossil porpoise-skull from the Miocene- strata of the
Taman Peninsula as Pnlirobhocuna, regarding it as represent-
ing an ancestral member of the group.

Sept., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

231

P hotography .

Pure and Applied.

By Chapman Jones, F.I.C, F.C.S., &c.

The Developable Image. — Professor J. Joly, in his
presidential address to the Photographic Convention,
deals with the nature of the developable imag:e. He con-
siders the change to be of a physical nature, and with
due reserve suggests photo-ionisation as the cause,
admitting, at the same time, that he has not as yet
been able to detect any electronic discharge from the
film under light stimulus. I should like to ask whether
the wonderful persistence of the developable condition
is not a considerable difficulty in the way of accepting
such a theory. Whether or not it is supposed that the
almost inconceivably minute stimulus that we know to
be sufficient to produce the developable condition does
so by effecting a change in the electrical condition of
the salt, it must be remembered that the changed state
of the salt is able to persist for years in an aqueous and
salt-containing medium, that is, without insulation, and
in the case of the Daguerreotype on the surface of the
best known conductor. As Professor Joly says, "our
knowledge of the electron as an entity taking part in
many physical and chemical effects, should be kept in
sight in seeking an explanation of the mode of origin of
the latest image," and it is, I submit, of even greater
importance to be guided by known facts and experi-
mental data, and to go forward in our conceptions only
as these justify our progress. lonisation may serve well
as a working hypothesis, whether or not the future will
prove, but I think it should not be accepted even as a
possible theory of the nature of the developable image
until some definite experimental support can be shown
in favour of it.

Measuring Vessels. — I suppose that it is correct to
regard weights and measures simply as conveniences,
and to value all arguments put forward in favour of this
or that system by comparing them from the same point
of view. The superior convenience of one system over
another may be the merchant's, or it may be his
customer's, and then the man of business has to en-
deavour to find the value of the respective conveniences
that he may follow the more profitable course. The
practical photographer is not concerned with profits in
this matter, but only with minimising his own trouble.
Unless one is already more accustomed to the metric
system, there can be no doubt that, at present, the
ordinary English weights and measures are more con-
venient for English people, for all English formula are
so expressed. But among all the arguments set forth
in favour of either our present methods or the annihila-
tion of them in favour of the metric system, there is
one very practical matter that I do not remember having
seen emphasized as it deserves to be, namely, the
shapes of the measures in common use. Whether one
purchases a two-dram, two-ounce, four-ounce, pint, or
quart measure, it is almost always of a convenient
shape, but measures on the metric system are tubular.
Of course, a narrow tube is better adapted for exact
subdivision, but exactness is not the primary desidera-
tum ol the practical photographer — an error of a few
per cents, on either side of the true capacity is negligi-
ble because the effect of the difference is rarely
recognisable. The photographer wants convenient
vessels for pouring from and into, when a flat dish is

the other receptical. I think this simple but very
practical matter well worth the serious attention of
those reformers who are seeking to get the metric
system universally adopted.

Fine Grained Images. — Messrs. Lumiere and Seyewetz
find that a finer deposit than otherwise is obtained by
developing slowly (by adding either water or a re-
strainer) in the presence of a solvent of silver bromide.
For this latter they use from 15 to 20 grams of
ammonium bromide to each 100 cc. of developer.
Paraphenylene-diamine and orthoamidophenol need no
such addition, as developing solutions prepared with
them have the necessary solvent power. W'orking on
such lines will probably be found to incur risks not
usually met with. Silver in solution is liable to give
stains, as with ammonia developers that were generally
used before soda developers became so common. I
think that the almost universal use of sodium carbonate
instead of ammonia is a case of the survival of the
fittest, and that it would not be well to go back to
ammonia with all its uncertainties. A fine grained
image is not everything, and the old wet collodion
plate, which is often taken as the standard, if developed
with ferrous sulphate, gave a coarse grain, though the
particles were more uniform in size than is generally
the case in gelatine plates. It is not so much the
coarseness of grain in gelatine plates that causes
trouble, as the presence of a comparatively small pro-
portion of large grains, some of which appear to be
often due to imperfect filtration of the emulsion, for
they settle down to the lower side of the film. But
granting that the proposed methods are not the best
for general adoption, cases may arise where they will
be serviceable, and it is very desirable to know the
characteristic effect of any possible procedure. In the
presence of the solvent of the silver salt, it is supposed
(.-md doubtless it is a fact) that some of the silver that
forms the image is deposited from solution, a kind of
intensification effect, the other part being reduced, as
usual, from the solid particles of salt as contained in
the emulsion. It would be interesting to know what
effect, if any, the double origin of the developed image
has on the gradation.

licccjvcd. — J. H. Dallmeyer, Ltd., send a catalogue
of their well-known lenses and other specialities. The
frontispiece shows the usefulness of the "Adon," which,
although a small lens intended for attachment to hand
cameras, has here, used alone, given an excellent
12 by 10 photograph with a camera extension of 38
inches.

REVIEWS OF BOOKS.

The Preparation and Mounting of Microscopic Objects, by T.

Davies (C. Arthur f'earson ; fcap. 8vo, pp. iiS; js.). This

is a reprint of a book which has had a large sale in past days ;
and, in spite of certain faults of arrangement, not only was
well worth reprinting, but deserved to be reprinted in better
style than the " edition " now before us. The book is mani-
festly merely a new impression from the old stereotype plates
of 1873, though this is not mentioned; the binding and the
paper have alone been altered — the latter very much for the
worse. In fact, the paper is both thick and coarse, and quite
unsuitable for the purpose, though the price at which the book
is published would surely have justified more satisfactory
treatment in this respect. The book itself is too well known
to need criticism. It was, of course, written entirely for the
amateur ; and, though somewhat out of date now, contains
much information on preparing and mounting objects for the
microscope which is of real service. — F.S.S.

232

KNOWLEDGE & SCIENTIFIC NEWS.

[Sept., 1905.

Half-Hours with the Microscope, by Edwin Lankester, M.D.
(C. Arthur Pearson ; fcap. Svo, pp. iiS ; is.).— This is another
reprint of a book which has been very popular in its day, but
the same criticisms as to paper and printing apply also to this
volume. Moreover, the book, dealing as it does in part with
the microscope itself, shows its antiquity ver>' markedly, though
the publishers refrain from giving any direct information on
the matter. For instance, on page 5 a microscope is illustrated
which contains almost everj- feature that the amateur would
be warned against now, and on pages 26 and 27 are two
" illustrations " which are so worn as to be little better than
shapeless smudges. The eight original plates of various objects
are in much better condition, and the accompanying letter-
press will still interest anyone who has just become possessed
of a microscope and is eager to use it. — F.S.S.

Microscopes and Accessories: How to Make and Use Them,
edited by Paul N. Hasluck iCasscll and Co., Limited ;
pp.160; IS. net). — It is difficult to know what to say of a book of
this sort. It is one of a series of '• Work " Handbooks dealing
with such multifarious matters as beehives, boot-making,
bamboo-work, &c. It professes to be a " comprehensive
digest of the knowledge of microscopes and accessories,
scattered over twenty thousand columns of ' Work,' a journal
edited by the editor of this book. We have a great sympathy
with amateur hobbies, and for all attempts to make things
instead of buying them; but we do not think the microscope'
is a suitable instrument for home manufacture, and this little
book, however praiseworthy in intention, confirms us in this.
It would be easy to criticise the design and details of the
suggested microscope, but we feel that any amateur who is
capable of making even such a microscope as is described
here, and of fitting it, moreover, with an elaborate iris diaphragm
also of his own manufacture, is himself to be humbly admired
rather than criticised. Instructions are also given on how to
make " an improved mount for a cheap microscope," the
result being such as may one day grace the collection of the
Royal Microscopical Society as a curiosity, and give rise to
much discussion; whilst in Chapter VII. very detailed instruc-
tions are given as to how to make a turntable for ringing slides
(ordinarily bought by unambitious workers for a few shillings),
to fit it with cog-wheels derived from an old egg-beater,
and to make also an electric motor to drive it ! About fifty
pages of the book are, however, devoted to really useful
elementary instructions as to collecting, preparing, and
mounting objects for the microscope.- V. S. S.

Modem Theory of Physical Phenomena, by Augusto Righi.
Translated from the Italian by Prof. Trowbridge. (Mac-
millan, 5s. net.) The mere title of this little work and the
name of its author are quite sufficient to arouse an interest
and to give promise of the volume being one worth careful
perusal. The author describes it as " an entirely unpretentious
book," but it is, nevertheless, one which will appeal to a large
number of readers, and will, we feel sure, satisfy their require-
ments. The chapters on Electrolytic Ions and Electrons ;
Electrons and Light; the Cathode Kays; Ions in Gases and
Solids ; Kadio-Activity ; and the Constitution of Matter,
which are described in such a pleasant, simple way, arc just
such as are in much request at the present time. A "biblio-
graphy," or list of papers on the subjects treated of, forms a
valuable appcndi.x.

British Bird Life, by W. Percivall Westell (London : Fisher
Unwin, iijos). — The number of books which have appeared on
British Birds is appalling ; and of these only a very few can
be regarded as really good of their kind. What excuse there
can be for the appearance of the present work we fail to see.

According to the author it presents a series of popular
sketches of every species of bird now regularly nesting in the
Hritish Isles. But many of the birds included in this list are
all but extinct as breeding birds and are nowhere common.
(Jn the other hand, a host of birds that are plentiful enough
during certain parts of the year find no place in this volume
at all, simply because they do not remain to breed.

Of the numerous illustrations .scattered throughout these
p.iges we can speak favourably only of the photographs from
life, some of which are very good ; the original drawings are
bad, without exception. Many can only be described as
caricatures. W.P.P.

Six Months In the Sandwich Islands, by Isabella L. Bird (Mrs.
Bishop) (London: John Murray, 1905 [Popular Edition] ;

2S. 6d.). — This is the companion volume to " L'nbeaten Tracks
in Japan," and it is written in the same charming style.
The first letter of the series appears to have been penned on
January ig, the last on .Vugust 6, 1S75. They contain vivid word
pictures of earthquakes and tidal waves, human sacrifices,
scenery, and domestic customs. Among the last we may
specially refer to the practice of lomi-loiiii. or massage as fol-
lowed by the Hawaiians. "The first act of courtesy to a
stranger in a native house is this (massage), and it is varied
in many ways ; now and then the patient lies face downwards,
and children execute a sort of dance upon his spine ! "

Keen powers of observation, and a peculiarly happy style
of recording what was observed are evident in every page.

Astronomers of To-day, by Hector Macpherson, Junr. (Gall
and Inglis); price 7s.6d.net. This collection of biographies,
accompanied by 27 portraits, should prove of interest to all
interested in astronomy, including as it does, an account of
the principal doings of many of those, foreign as well as
British, of the present day who have made a name for them-
selves in this branch of science. The series is by no means
complete, however, for such names as those of Sir W. Christie,
Astronomer Royal ; Professor H. H. Turner, Savilian Professor
of .Astronomy ; Mr. W. H. Maw, President of the Royal Astro-
nomical Society; and Mr. Crommclin, President of the R. A. A.,
are conspicuous in their omission, and there are others that
might well have been included, but it is, of course, most diffi-
cult to decide on where to draw the line in such a list so as to
include the biographies within a handy volume.

Publications of West Hendon House Observatory, Sunderland.

(T. W. Backhouse.) — We lia%e recei\ed \'ohiino III. of the
West Hendon Observatory publications, containing observa-
tions of 49 variable stars made in the years 1S66 — 1904 by the
author. In most of these observations, except in the case of
T Coron:e, the variable differs much in colour from the com-
parison stars ; this makes the probable error greater than in
the case of stars of the same colour. In the catalogue given
the stars are arranged in order of their Right .Ascension, the
positions being given for epoch 1900. Then comes the average
colour and degree of redness, the spectrum type according to
Kriigcr, and the comparison stars examined.

Pyrenean Geology. Part IV., "The Structure of the Pyrenees ;
PartV'., " Engineering Geology in the Pyrenees; " price fid. each
part. By P. W. Stuart-Menteath, Associate of the Royal School
of Mines. Eight parts in all are in preparation, the last to be
entitled "The Convictions of the Monkey Mind," the connec-
tion with Pyrenean geology being at present somewhat obscure.
When speaking from his own experiences in geology, the
author is readable, but we cannot see the necessity of intro-
ducing into what purport to be geological works personal
squabbles and acrimonious remarks concerning those who
differed from the author.

A Scheme for the Promotion of Scientific Research, by Walter
B. Priest (Stevens). — In this small book a project is set forth
in detail whereby an inventor may obtain a public grant for
the completion of his discovery. This idea in general is most
desirable ; but we fear that in practice there would be ex-
treme difficulties in carrying it out. Applications are, accord-
ing to this suggestion, to be referred to the Board of Trade for
consider.ation. This department, wc are inclined to think,
would have to be very greatly enlarged to bo able to cope with
the thousands of applications that would certainly be sent in,
and the amounts applied for would undoubtedly run into
millions of pounds. We quite agree with the writer, sup-
posing such a scheme could be satisfactorily arranged, in
(juestioning" whether money so employed would not iiltiiiialcly
promote more effectually public interests than much of that
now devoted to educational purposes which entail so gre.it a
national expenditure."

The Country Gentlemen's Hstate Book, lOO.?. Edited by William
Broomhall (The touiitry Gentlemen's Association, Limited;
price los. fid.). This is the third issut of .an annual hand-
book which should prove of the greatest use to those owning
property in the country. It gives interesting articles and infor-
mation on the man.agement of estates, farming, gardening,
forestry, sport, and many other useful topics. It is a large
book of over 400 pages with many illustrations.

Sept., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

233

Notes on Volumetric Analyses, by J. B. Russell, B.Sc, and A.
H. Hell, B.Sc; pp. VIII. and 94 (London: Murray; price 2s.).
— This little book contains concise directions lor carrying out
most of the usual methods of volumetric analysis, and will be
found of great use by those who have made some progress in
analytical chemistry. It is a new and enlarged edition of the
"Notes" published in i8g8, the additional matter including
various methods of standardising acids. Working details are
given at some length in the earlier chapters, but are very wisely
curtailed in the latter pait of the book, with the object of
making the student do some thinking for himself.

Elementary Experimental Chemistry, by A. E. Dunstan, B.Sc,
pp. VTII. and 173 (London : Methuen ; price 2S.). — If a book
on chemistry is to be anything more than a collection of dis-
jointed facts to the student each fresh step must be illustrated,
as f.ar as possible, by experimental work. This is never lost
sight of by Mr. Dunstan, and almost every page of his book
gives directions for simple experiments bearing upon the theory
of the subject. Though primarily intended to cover the
ground for such examinations as the Oxford and Cambridge
Junior Locals, the Chemistry is something more than a mere
" cram " book, and we can thoroughly recommend it also to
beginners who have not the goal of examination before them.
A small point by way of criticism is that a brief description
might have been given of the bearings of the recent dis-
coveries about radio-activity upon the atomic theory, for this
is no more abstruse than many of the subjects with which the
author deals so clearly.

Modern Electricity, by Henry and Hora (Hodder and Stough-
ton ; 5s. net). — This book claims to be a practical working
encyclopaedia on the subject, and has been prepared with a
view of meeting every emergency that might confront the elec-
trical engineer and inventor. The object has been to simplify
the information without sacrificing its clearness or accuracy,
so that every apprentice and artisan will be able to gain a
complete knowledge of the fundamental principles and applica-
tions of electricity. These high claims are not alvvays justi-
fied. For example, it is not true always to say that an induced
charge is equal and opposite to the inducing charge ; and in
the particular example given they are not equal. On page 21
a question is propounded : Two spheres charged with 4 and 5
units respectively are placed two centimetres apart. What
force will they excite on each other ? The question is suc-
ceeded by the following enigmatical "solution." "Any result
equals the force divided by the resistance. The force is 4
multiplied by 6 ; therefore the resistance must be 2 multiplied
by itself.

i-^ = 6 dynes. Ans."
2x2
This solution may be simple; it is certainly not clear. There
is too much of this kind oi thing in the book for us to be able
to recommend it enthusiastically. At the same time there is
a great amount of usetul information gathered together here in
connection with accumulators, decomposing vats, carborun-
dum, central exchanges, Crooke's tubes, lightning arresters,
lamps, cables, &c., &:c. ; and a large number of examples are
worked out which will be useful to those who want to get at a
result without caring for much refinement in the way they
reach it.

The Electromagnet. Underbill (London: E. and F. N.
Spon. A new and revised edition). — It is introduced by a
capital portrait of Joseph Henry, of Philadelphia, who antici-
pated Faraday in many of his discoveries. It is an eminently
practical volume, and should prove of great service as a refer-
ence book to those who are concerned in the manufacture of
electromagnets. In the briefest possible space a succinct
account is given of all the details which the practician can
meet with in regard to choice of dimensions, wires. Sec. There
are a number of important tables, and also numerous problems
to which answers are given. It is very neatly and carefully
printed.

Elementary Plant Physiology, by D. T. Macdougal, Ph.D.
(Longmans, Green, and Co., 1902. 108 illustrations. Pp.
138). — This is a useful guide in a small compass to the subject
with which it deals. Some of the illustrations are very sug-
gestive, and will be of use to the teacher of botany looking
about for striking methods of treatment. The chemistry of
respiration and digestion is dealt with in an interesting as well
as a scientific manner.

ObservQction of the
ToIslI E^clipse.

The following list shows the arrangements for observing the
total eclipse on August 30: — •

Observers and Observatories
Represented.

Labrador

(Lake
Melville.

spam.
(Burgos.)

(T ortosa.)
(Oropesa.)

Dr. King (Ottawa Obs.).

Mr. E. W. Maunder (Greenwich).

Mr. Perrine (Lick Obs.).

Balearic
/^/l■s.
(Palma.)

(Colum-
bretes.)

Algeria.
(Guelma.)

Tunis.
(Sfax.;

Egypt.
(Assuan.)

Mr. J. Evershed.

Rev. J. S. Cortie (Stonyhurst).

Prof. Callendar \ ,„ , ,- ,,
Prof. Fowler (^oyal College

Mr. Shackleton ) °^ Science).

Mr. Campbell (Lick Obs.]

Sir N. Lockyer ) (Solar

Dr. \V. J. Lockyer [ Physics
Mr. C. P. Butler ' Obs.).

U.S. Naval Obs.
German Party.

Mr. H. F. Newall (Cambridge).
M. Trepied (Obs. of Algiers).

The Astronomer-Royal 1 ,^

Mr. F. W. Dyson ^^"f^

Mr. Davidson ) ^'^l^)'
M. Bigourdan (Paris).

Prof. Turner (Oxford).
Mr. Bellamy.

Mr. Hussy (Lick Observatory).

Plan of Work.

1 Search for Intramer-
curial planets.
Large scale photo-
graphs of corona with
40' camera.

Prismatic reflector pho-
tographs of spectrum
of chromosphere and
• corona.

f Experiments on coronal

radiation.
Photography of red and
I green regions of spec-
trum of chromosphere
^ and corona.

> Search for intramer-
curial planets.

Large scale photo-
graphs of corona with
40' camera.

Polarisation observa-
tions.

Spectroscopic photo-
graphy of chromo-
V sphere and corona.

Prismatic camera (3
prisms) photography
of spectrum of chro-
mosphere and corona.

Large scale prismatic
reflector (one prism)
photography of spec-
trum of chromosphere
and corona.

Small scale photo-

. graphs of corona.

Spectroscopic and
polariscopic observa-
tions.

1 Photographs of corona
on 4" and ij" scales.
Spectra of chromo-
sphere and corona
with Major Hills'
> spectroscopes.

/ Polariscopic observa-
tions.
) Corona photographs
1 with Abney doublet.
Large scale photographs
^ of corona.

/ Search for intramer-
I curial planets.
Large scale photo-
graphs of corona with
1 40' camera,
j Integrating speotro-
\ scope photographs.

234

KNOWLEDGE & SCIENTiriC NEWS.

[Sei't., 1905.

Conducted by F. Shillington Scales, f.r.m.s.

The Blacck CurroLnt
GaLlbmite.

Bv Alice L. Lmbleton, B.Sc, F.L.S., &c.

This disease is caused by a creature only one-half of ;
millimetre in length, yet it does enormous damage.
Its worm-like body has four short legs near the head,
and two long tail bristles. The disease is known to
gardeners as " knotting" or "knobbing," and growers
sre only too familiar with it; yet gardeners (especially
cottage gardeners) are often the worst ofTenders in
spreading the pest, for they propagate diseased cut-
tings on the ground that those particular trees produce
best " fruiting l)uds " — which buds are precisely those
that are swollen with the mites, and are wor.se than
useless. In reality there is no difficulty in recognising
infested bushes, for the buds arc swollen so that they
are at least three times as large as normal buds, and it
is exactly this that leads to the common error of believ-
ing these identical buds to be fine "fruiting buds."
While these buds are still green, with a strong magni-
fying ghiss, one can see them, when opened, to he
literrdly a mass of the parasites. Such buds usually
never open at all, but remain on the stems as brown,
dry knobs; if not so badly diseased, they occasionally
send out one or two feeble little leaves, but never any
more. .As the hold of the disease on the plant in-
creases, the effect becomes very striking ; the failure of
a large number of the buds forces into premature de-
velopment buds which normally would open the follow-
ing year, making overdrafts in this way on the plant's
vitality ; after some time it is incapable of responding
to these abnormal calls, for the provision for next
year's foliage is already exhausted, jmd the plant dies.

All the winter the mites, in all stages, from the egg
up to adults, are tightly shut up in the buds, and they
only begin to come out in the spring — a few pioneers
may even be .seen as early as March, but the great host
get fret- in .May. In the severest frosts, they are un-
harmed in their protected quarters ; in fact, they seem
to revel in a hard frost, and it is indeed wonderful hov
their tiny bodies resist King Frost.

During their migration perifxl, which is from the
middle of May to the middle of June, they exhibit
curif>us methods of locomotion ; the four short anterior
legs are ill-adapted for walking, and yet they continu-
ally crawl alxiut at a rale of twelve to fifteen times their
own length in a minute ; but this only lakes them from
bud to bud, at the farthest ; they get carried further
afield by passing insects and spiders, to which they
adhere first by the stickiness of their bodies, and then
by coiling round a hair or antenna in a worm-like
fashion, and holding on tenaciously. This can Ix;
shown by lightly touching an open, infested bud with a
fine camel's hair brush, when the little white creatures

will be found wriggling among the bristles, yet holding
on in a determined manner. Their third method of
getting about the world is the most interesting. If
cne watches a community of these mites in a bud under
a microscope, one sees them continually standing up on
their tails, waving the front legs agitatedly ; then they
suddenly disappear, and at first it is hard to imagine
what has happened precisely. Tlie disappearance is
not so accidental as it seems ; the animals are, in fact
leaping ! The two tail bristles act as springs, and tne
mite covers about sixteen or twenty times its own
length at a jump. It is always seen that after standing
upright, waiting f( r a friendly insect to carry it off on
its unsuspecting body, the mite ceases to wave its legs,
remains rigid for a moment, and then launches itself
forth, torpedcv-like, into space. It is an entertaining
spectacle to watch, for occasionally, by retaining too
firm a hold on the bud, the leap is rendered abortive,
and the mite simply falls backwards with considerable
impetus, instead of making a clear jump. It is a sug-
gestive fact that while the mites remain upright for
minutes in the still air of a room, yet they can be in-
duced to leap at once by blowing upon them. It
seems, therefore, that they first try tO' get an obliging
insect to carry them away, and, failing this, take
advantage of a puff of air to make their blind leap.
Perhaps the mile succeeds in "boarding" :i passing in-
sect which hovers near enough to fan it by the heating
of its wings.

Having vacated liuir winter home and cr.iwled. or
been carried, or Ic.ipt to fresh pastures, the mites
enter into the new young buds which are just formed,
and so set up the vicious circle again. Myriads are
lost, for tho.se which fall to the ground perish, but very
few are sufficient to carry on the species for the next
year, for they multiply, as soon as they get into the
new buds, at an amazing rate. They set up in the new
buds at the beginning of June, and by the middle of
the month they are all housed (or else they have
perished), and the migration period is over, and of the
hosts of mites which are turned loose into the world
in May, only an infinitesimal number has obtained a
footing in the now buds. Reproduction goes on at an
almost incredible rate through July and August, and
all the winter the tightly-folded buds arc crowded with
their unwelcome lodgers.

The question, of course, is "hf)\v can we check the
ravages of these creatures?" and this c.in only be
answered by studying their life-cycle ;is given above,
and carefully considering at which points they arc most
open to successful attack. In very bad cases it cer-
tainly is best to cut down the bushes in the winter and
burn them on the spot, for the mites are then all safely
shut up in the buds, and the bushes can be dealt with
in this way without any fear of spreading the pest by
shaking them on to other trees, or by .scattering them
to the winds. Any treatment of the ground under
infested bushes is practicdly unnecessary, as the mites
do not live in the soil. ;Vs regards spraying, it is
manifestly useless during the winter, when the mites
are safe in the buds, and here I may call altcntion to a
misleading statement made hy the Board of Agriculture
(A 1-93 — I, I'"eb., 1893): — "Spraying. ... in the
autumn before the weather becomes cold, and just after
the leaves have f.illen, if possible, lliis will econo-
mise liquid and l,il)our, and will affect the mites before
they get into the buds." I simply quote this in case
it is doing damage by being so erroneous, for the mites,
as stated above, are already in the new buds in June.

Sept., 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

235

The only time at which spray infj can be of use is during
the migration time, i.e., from the middle of May to the
middle of June, and then, unfortunately, it is undesir-
able on account of the blossom. On the whole, hand-
pickiny is the only reliable method, and this should be
done when they have g-ot into the new buds, for then
their numl>er is reduced to a minimum, and the re-
moval of all the new infested buds in July would appar-
ently clear the plants of the disease. When black cur-
rants are gfrown extensively, hand-picking- is a serious
consideration, yet it is the best method that can be
recommended. If this method be adopted annually the
disease can be reduced tO' a negligible quantity within
three years. The picked buds should always be burnt
carefully, and not "dug in."

CleaLiiing Desmids.

The cleaning of Desmids is generally somewhat
troublesome, and many of my readers may be glad to
know of a simple method of procedure adopted by
Professor G. H. Bryan, and communicated tO' the
American "Journal of Applied Microscopy." . Tlie
method to be described is particularly applicable to
material obtained from mountain bogs containing sub-
merged plants of Sphagnum, among which specimens
of the genera Micrasterias, Euastnim, Clostcrium, Vcniitm,
and others abound. To' collect desmids from this
source, a good plan is to squeeze the Sphagnum mXo a
wide-mouthed bottle, but the majority of desmid
gatherings appear amenable to the same method of
cleaning. The apparatus recjuired consists of one or
two shallow porcelain saucers or photographic dishes,
an old pomatum pot being useful among the number,
and a tapered glass tube with a rubber cap, such as a
"filler" for a fountain pen. A gauze strainer for a
coffee pot is useful for straining out any large pieces of
dirt, tlie stuff left behind being examined for filamentous
desmids. The strained material is run intO' one of the
porcelain dishes, and after a short interval — not more
than half a minute — the dish is inclined to one side
and gently rocked. Any desmids in the gathering will
be seen to collect in a bright green line, or patch, at
the edge of the receding water, and can then be readily
picked up with the pen-filler in an almost pure state.
On working round the edge O'f the dish, the desmids
may be drawn intO' green patches in almost any desired
part of the vessel, and one lot after another picked up
until there are none left worth troubling about. As the
desmids are removed, they are transferred to the poma-
tum pot, where a drop of Zenker's fixative suffices to
fix them. (The formula for Zenker's Fluid is Ka Cro O7,
2.5 grms. ; Na.j So^ i grm. ; Hg CI,, 5 grms; glacial
acetic acid, 5 cc. ; water ad 100 cc. Dissolve the Hg Cl^
and K. Crj O7 in the water, with the aid of heat, and
add the acetic acid in proper proportions as required,
as it evaporates readily.) By repeating the rocking
process, the desmids are again collected and transferred
from the fixative to another dish containing clean
water. They are deposited in a patch in the water near
the edge of the dish, and by repeating the rocking, the
fixative is gradually washed away, together with any
remaining foreign matter. The water should be
changed at least once. This method of washing in-
volves less loss of specimens than the ordinary decanta-
tion method, provided that care is taken each time to
deposit the desmids as close together as possible, for
the few desmids that are not picked up in the first

attempt are easily collected and picked up subsequently.
The whole process takes but half an hour or an hour,
so that the fixative is removed before it has time to
injure the colour of the specimens.

If much foreign matter is mixed with the origin.al
gatherings, the whole may be left in a wide-mouthed
bottle in the light for a day or two, when the desmids
will collect on the top of the sediment, where they will
increase and multiply. The surface layer, containing
the desmids, may then be syphoned off and cleaned a;
before. Even in poor material it is often possible, by
the rocking process, tO' collect with the pen-filler suffi-
cient desmids to mount one or twO' slides. A some-
what similar rocking process is useful for separating
Foraminifera from sand, but the rocking must be a little
more violent, and the sand is left behind, unlike the
flocculent matter in the desmid gathering, which is
swept forward by the water.

To' mount the desmids, Profesor G. H. Bryan takes a
small piece of parchment paper, say, i^ by i inch, or
less, such as is used for packing tobacco, and folds it
into a little box. The water with the desmids i.s placed
in the box, which is then floated on glycerine. In two
days the water will have diffused intO' the glycerine, and
! sufficient glycerine to penetrate the desmids will have
passed through the parchment intO' the bo'X. The
desmids are now ready for mounting in glycerine, and
have undergone no contraction.

Some desmids, notably Closterinm, have a tendency to
adhere tO' the bottom of the dish, and then float on the
water, but this tendency to float gives similar difficulties
when they are washed by decantation. As species < f
this genus multiply rapidly by self-division, it is usually
possible to start with sufficient material to allow of a
mall loss by flotation.

Action of Wood on Photogra.phic Plates.

In a recent number of the proceedings of the Cam-
bridge Philosophical Society, I'rofessor H. Marshall
Ward refers to W. J. Russell's recent memoir in the
" Transactions of the Royal Society," in which is de-
scribed the action of a number of different woods on a
photographic plate in the dark. Russell had suggested
hydrogen peroxide as the active agent, this re-agent
having a definite action upon photographic plates, and
the resin in the wood as probably the indirect causal
agent, adducing in support the experimental result
that while gum-like bodies are inactive, those of a more
resinous nature are active. Professor Marshall Ward,
as the result of numerous experiments, concludes that
the activity is not merely due to resin or resin-like
bodies, but that tannin and tannin-like bodies,
as well as some others, may also be responsible.
It is at least clear that some body or bodies in the
liquified cell-walls reduce silver salts in the plate, and
that these bodies are either shot off, as if volatile, or
diffuse readily, seems clear from the want of sharp-
ness in the microscopic details. Readers will find no
difficulty in carrying out the process if they care to
try it. The sensitive film of the dry plate is merely
placed in contact with the smooth dry face of a wood
block and left in darkness for periods of varying length,
and the plate on development should show an image
of the wood, knots, for instance, being particularly well
marked.

[Communicatioin and enquiries on Microscopical matters should be
addressed to F. Shillington Scahs, "Jersey," St. Barnabas Road,
Cambridge.]

236

KNOWLEDGE & SCIENTIFIC NEWS.

[Sept., 1905.

The Face of the Sky
for September.

By W. Shackleton, F.R..\.S.
The Sun. — On the ist the Sun rises at 5.13 and sets at
6.47 ; on the 30th he rises at 5.59, and sets at 5.41.

The equation of time is negligible on the ist, the Sun
being only 4 seconds after the clock at noon.

Autumn commences on the 23rd, when the Sun enters
the sign of Libra at 5 p.m.

Sunspots and prominences are numerous. The posi-
tion of the Sun's axis and equator is as follows : —

Axis inclined from N.
point.

Equator S. of
Centre of disc.

Sept. I ..[

21°

15'

7° 12'

.. II ..'

23°

29'

t 14'

,. 21. .i

25°

■f 2'

Oc>. I .J

26°

10'

6" 37'

The Moon : —

Date.

Phases.

H. M.

Sept. 6 ..
., 13 •■
,, 21 ..
.. 28 ..

]) First Qaarter
0 Full Moon
d Last Qaarter
• New Moon

4 9 a.m.

6 10 p.m.
10 14 p.m.
10 op.m.

Perigee 225,003 mites
Apogee 252. 30D ,,
Perigee 222,600 ,,

II 18 a.m.

4 36 a.m.

5 12 p.m.

OccuLT.\TioNS. — The following are the brighter stars
which suffer occultation visible at Greenwich : — ■

I>iS3ppearance.

Reappearance. |

Mag.

Angle

Moon's
Angle J Age.

Mean

fromN.

Mean

fromN 1

Tim;.

point.

Time.

point. 1

pm.

p.m.

d. h.

Sept. 4

1 Librae . . . .

4'I

7-33

8,"

8.37

301° 5 6

., 10

29 Capriccmi

10. 21

.37-'

11.27

287° I II 9

.. 17

^ Ceti

4-4

10.3s

42°

11.36

2750 1 18 9

,. 18

/ Tauri . . . .

4 3

9-54

65"

10 55

259° '9 9

.. >9

1 Tauri .. ..

10.36

8°

10.59
a.m.

382' 10 9

■ • 20

■ Tauri . . . .

'■'

8.24

26°

322° 1 20 20

The Planets. — Mercury is a morning star in Leo ;
he is at greatest westerly elongation on the 15th, when
he rises about 3.45 a.m. This is a favourable elongation
for observation of the planet in the morning.

Venus is a morning star in Cancer and Leo; near the
middle of the month the planet rises shortly after 2 a.m.
On the morning of the 26th the planet will be in con-
junction with Kegulus, being only 16' away to the
north.

Mars is a feeble object in the S.W. evening sky,
setting about 9 p.m.

Ceres is in opposition on the 4th ; the magnitude of
the minor planet is 74, but it is badly placed for observa-
tion, being low down in Aquarius.

Jupiter rises about 9.30 p.m. on the ist and about
7.45 p.m. on the 30th, Towards the end of the month
he will be the most conspicuous object in the sky, looking
east about 10 p.m.

Saturn, though somewhat low down in the sky, is suitably
placed forobservatii n, being on the meridian at 10.25 P**"

on the 15th. The planet is a fairly conspicuous object in
the evening sky, looking S.E., about 9 p.m., and is easily
distinguished by its dull yellowish colour. As seen in
the telescope, the planet always appears a beautiful ob-
ject, and well repays observation. The polar diameter
of the ball is i7"'4, whilst the major and minor axes of
the outer ring are 43""5 and 8"-2 respectively ; thus the
ring plane is inclined to our line of vision at an angle of
1 1 , the northern surface being visible.

Uranus is on the meridian about fi.30 p.m. on the
15th. The path of the planet lies in Sagittarius, in
which constellation he will appear for several years to
come. The planet is in quadrature with the Sun on the
24th, and is situated about 2A south of the 4th magni-
tude star M Sagittarii.

Neptune rises about 11 p.m. on the 15th; he is situated
about 6" east of the star in Geminorum.

Minima of .\lgol occur on the 8th at 10.20 p.m., and on
the nth at 7.19 p.m.

Mira Ceti is due at minimum on the ijtii; magnitude
about 8-5.

Telescopic Objects: —

Double Stars. — Polaris, mags. 2-1, 9-5; separation
i8"'6. The visibility of the small star is used as a test
for a good 2-inch object glass.

f Sagittae XIX.'' 45"", N. 18° 53', mags. 5, 10; separa-
tion 8"-6.

a', a-' Capricorni XX."" 12"", S. 12'' 51', mags, n' 4-5,
a- 3-8; naked eye double, separation 373", very easy with
opera glasses.

7 Delphini XX. "^ 42"", N. 15" 46', mags. 41, 5*0 ; sepa-
ration ii"'8. \'ery pretty double for small telescopes;
brighter component yellow, the other light green.

Nebulae, tk.c. — Dumb Bell nebula in X'ulpecula, nearly
4° due north of 7 Sagittae. Katlier faint object in a
3-inch.

(M 8) Cluster in Sagittarius ; large luminous field of
small stars; fine object in pair of field glasses. About a
degree E. of the star 4 Sagittarii.

Roya-l School of Mines.

Till-: Marquess of Londonderry, K.G. i I'lisidi-iit of the
Hoard of Education), has .-ippointed Mr. S. Herbert Cox to
the Professorship of Mining .it the Koyal School of Mines.
South Kensington, vacant on the death of Sir Clement le Neve
Foster. In view of the changes in organis.ition that may be
found desirable in the Koyal College of Science and the Koyal
School of Mines after the completion of the investigations now
in progress by the Departmental Committee, it has been
thought best to make this appointment a temporary one.
Mr. Co,x is an Associate of the Koyal School of Mines. After
experience as Assistant Geologist and Inspector of Mines in
New Zealand, he was appointed Instrnctor in Geology,
Mineialogy, and Mines in Sydney Technical College; con-
currently with his tcnnre of this oflicc he was employed to give
technical lectures at various mining camps in New South
Wales, and practised as a Mining luigineer. Since ifScjo he
has been entirely eng.iged in private practice, and has had
experience of mininR in I'.ngland, France, Spain, ICgypt, the
United States, and Canada. Mr. Cox was President of the
Institution of .Mining and Metallurgy in 1899-1900.

Lantern Slide CAniNETs. — Messrs. Flatters & Garnett, of Man-
chester, have just placed on the maiket a new form of cabinet for
storing lantern shdcs. They arc very compactly built up of
various numbers of drawers, each holding 100 slides, and being
wlihout grooves damage lo the binding is avoided. The cabinets
are fitted in such a m<inncr a,s to render the extraction and replace-
ment of a given slide the work of a couplj of seconds. The same
firm also offcis an improved style of "despatch box " for carrying
lantern >1ides. These arc fitted with rubber packing to prevent
breakage. Both articles are very moderate in price.

237

KDooiledge & Seientlfle jlems

A MONTHLY JOURNAL OF SCIENCE.

Conducted by MAJOR B. BADEN-POWELL, F.R.A.S., and E. S. GREW, M.A.

Vol. II. No. ii.

[new series.]

OCTOBER, 1905.

[stJSne's' Hall ] SIXPENCE NET.

CONTENTS.— See Page VII.

The Two New
SaLtellites of Jupiter.

By A. C. D. Crommelin.

It has been my privilege to chronicle in these columns
two very sensational astronomical discoveries in the
last seven years. The first was the minor planet, Eros,
which proved to be our closest planetary neighbour;
the second was Phoebe, Saturn's ninth satellite, notable
for its immense distance from its primary, and still
more for its retrograde motion. The zeal and skill of
American astronomers has been rewarded with three
more discoveries in the satellite world during the last
few months, all of which present some points of special
interest.

Till 13 years ago it was entirely unsuspected that
any further mysteries lay hidden in the Jovian family.
The four Galilean satellites had been known for nearly
three centuries, and formed a symmetrical system of
worlds, comparable with our moon in size, revolving
in almost circular orbits near the plane of their
primary's equator. The discovery of a fifth member
of the family by Prof. Barnard in 1892 excited great
interest; this was a very minute world, but resembled
the others in the shape and plane of its orbit. Its chief
mathematical interest lay in the rapid motion of the
perijove produced by its proximity to Jupiter's equa-
torial protuberance.

It was doubtless the discovery of Phoebe that
suggested the search for very distant satellites of
Jupiter, which Prof. Perrine undertook last winter with
the Crossley reflector, and which proved successful be-
yond expectation, resulting in the discovery of two
more tiny members of the system. It must be con-
fessed that the Lick observers were somewhat tardy in
distributing information on the subject to Europe, so
that we were for a time in uncertainty as to whether
the new worlds were really satellites, and not minor
planets, which happened to be hovering in Jupiter's
vicinity. However, there is now no doubt at all that
VI. is a true satellite, and scarcely any doubt in the
case of VII.

Dr. Frank E. Ross has deduced approximate ele-
ments of their orbits from the observations extending
up to March last. As satellite VI. has been again ob-
served at Mount Hamilton at the end of July I have
used the new observations to correct his elements of

this satellite, but as no recent observation of VII. has
been reported, his elements are given unchanged.

Prof. Perrine had previously announced that the
motion of VII. was probably retrograde. Dr. Ross,
however, finds that direct motion is much more
probable, though the matter is not absolutely certain
till the satellite is re-observed or till some images of it
are found on Harvard photographs of the neighbour-
hood of Jupiter taken some years ago. Several of
these photographs are available for the search. *

The most extraordinary features of these orbits are
their high inclinations to both the equator and orbit of
their primary and to each other. The satellites of
Mars, Jupiter {5 inner), Saturn (7 inner), and Uranus
(probably) move almost exactly in the equatorial plane
of their primary, while our moon, Japetus, and Phoebe
deviate from this towards the orloit plane of the
primary. Neptune's satellite, indeed, appears to be
inclined at a considerable angle to both planes, but a
repetition of this anomalous feature in the hitherto
symmetrical Jovian system was quite unexpected. The
near approach to equality in the mean distances is also
curious, and the fact that the two orbits interlock, like
two links in a chain; in this respect they recall the orbits
of Mars and Eros. Their great distance from Jupiter
compared with the other satellites is also remarkable,
and suggests that they were not original members of
the system but have been added later. The capture
hypothesis is attractive, but there are grave mathemati-
cal difficulties to be overcome before it can be adopted.
It would seem that a planet cannot capture a body in
such a way as to make it travel in a closed path round
itself, but only round some other body, e.g., the vari-
ous members of Jupiter's comet family have been com-

SATELLITE.

VII.

Sidereal Period

253^.4

265d.o

Mean distance in miles. .

185,000

7,403,000

Least ,,

030,000

7,221,000

Greatest ,,

33.?. 000

7,585,000

Eccentricity

o-i6

0 0246

R.A. of Perijove

2690.2

33^°-2S

R.A. of Pole of Orbit Plane..

900

igio.13

Dec

870

63°.8

Perijove Passage . . -,

1904

Dec 15

1905 Jan. 2

igus

Aug. 25

1905 Sept. 24

-"i

Inclination of Orbit to Jupiter's

Equator

280.4

3i°-43

Inclination of Orbit to Jupiter's

Orbit

260.2

320.0

Inclination of Orbit planes to

each otfier . .

270.0

Maximum Elongation at Oppo-

sition

77'

70'

Direction of Orbital Motion

Direct

Stellar Mag

Prob. diameter in miles

100

•Observations of VII, in August have now been reported. They
confirm the direct orbital motion ; but appear to show that the
orbit is considerably more eccentric, and the period shorter, than
the values given by Ross.

238

KNOWLEDGE & SCIENTIFIC NEWS.

[October, 1905.

pelled by Jupiter to travel in ellipses — not, however,
around the planet, but around the sun. Until, there-
fore, some plausible suggfestion has been made of a
body that could have captured these satellites, not for
itself, but for Jupiter, the capture hypothesis can hardly
be resjarded as tenable.

Si.u .) M.U ( M.,„

r f tht',thrcc outcrino5t

^atelMtrs of Juplttr.

Though the two orbits interlock, yet owing to their
large mutual inclinations the satellites cannot approach
each other within half a million miles or thereabouts, at
which distance such tiny bodies could not perturb each
other appreciably. ,As the nodes and pcrijoves are
moving fairly rapidlf, it is
possible that after some

centuries the orbiis may in- »i p„, , r _

tersect. The prospect of an q,^ X yE^f^H^NPOLE
actual collision is, however,
very slender.

Dr. Ross calculates that
the node of VII. retro-
grades i''.i5 per annum,
while the perijove advances
i''.45. He finds the co-
efficients of the annual equa
tion, e\ection, variation, and
principal solar perturbation
in latitude to be 0^.42, o''.38,
o*^. 12, and o^.^o respectively.
The corresponding fjuan-
tities for V I. are considerably
larger than these, owing
to its greater eccentricit).
When these and other
f)erturbations have been
accurately determined, the
two new satellites will give
a determination of the mass
of Jupiter, which will be
entitled to great weight.

The diagrams of the poles
of the orbits, >)cc.,are given

as the simplest way of illustrating- their situation rela-
tively to the primary's equator, near which the orbits
of the five inner satellites lie. Owing to the proximity
of the pole of \"I. to our North Pole, the satellite is
nearly due east or west of Jupiter at elongation. The
pules are prob:ibly moving round the pole of Jupiter's
orbit as in the case of our own moon, Init the time of a
revolution is probably at least two centuries instead of
iSi years.

It will be seen that the orbits of both VI. and \'II.
are smaller than that of Phoebe, but their angular
distances at elongation are much greater, reaching to
1;}°. Their high inclinations produce most remarkable
twists and curves in their apparent motions seen from
the earth. A diagram is given showing their apparent
places at various dates extending from December 23,
1904, to November 13, 1905. The orbit of VII. is now
almost edgewise, and it must have nearly, if not quite,
passed across Jupiter's disc on July 18, but so faint an
object could not be seen when near its primary.

The direct motion of these satellites is unfavourable
to the hypothesis suggested by Prof. W. H. Pickering
to account for Phoebe's retrograde motion. According
to this the planets originally rotated backwards, and
very distant satellites should retain this primitive
motion, while solar tides were supposed to have re-
versed the direction of the planet's rotation before the
later satellites were born.

It c;m scarcely be accidental that retrograde motion
exists in the families of the three outer pl.Tucts, and in
these only. It must be confessed, however, that Prof.
Pickering's key to the enigma, which seemed so pro-
mising at first, can no longer be accepted with great
confidence, though it may be possible to modify it so
as to cover the new facts.

The numeration of Jupiter's f.imily is now in a state
of confusion, the order reckoning outwards from the
primary being V., I., II., 111., IV., VI., VII.

NPOL^ of XE'^'-""'''^

N.POL£ Of ^ JijP.'i ilai'troA

2. if. L s 'O '1.

,i JO

5tiit o j Dtc

OP "a.

Dlajcram shiiwin^ the f'o<iition.s of the Poles of the Orbits of VI. and \'ll., with
reference to Jupiter's bquator and licliptic.

October, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

239

yocr li ^

j nLy..,iUi of Arc

Apparent Motion of VI. and VII. in 1904-5.

A similar confusion formerly pre\ailed in Saturn's
system, and was remedied by dropping the numbers
and substituting names.

The four Galilean satellites were long ago named lo,
Europa, Ganymede, and Callisto. These names, how-
ever, are now seldom used. It would seem to be an ap-
propriate time t,o revive them in lieu of the more
prosaic numerals, and to give proper names to the
three new satellites.

The tenth satellite of .Saturn, recently detected on the
Harvard plates, is interesting from its period being
21 days, almost the same as that of Hyperion. This
presents another case of linked satellites, but in this
case, unlike that of \T. and VH., the planes of motion
are probably nearly identical, so that very close ap-
proaches are possible; it is rather curious that soon
after the discovery of Hyperion its minuteness
suggested that it might be one of a ring of satellites
analogous to the zone of asteroids, an idea which R. A.
Proctor endorsed in his imaginative essay, " A Voyage
to the Ringed Planet." This anticipation seems
worthy to rank with Swift's and X'oltaire's suggestions
of two Martian moons as a remarkable astronomical
prophecy.

It is satisfactory to learn from a recent Harvard
circular that Phoebe has again been photographed
during the present apparition of Saturn, the positions
agreeing so closely with those predicted from the ele-
ments given last year as to remove the smallest doubt
as to the substantial accuracy of the adopted orbit.

Dr. F. E. Ross has been engaged on the study of the
orbit and perturbations of Phoebe, and I understand that
his researches have already been published in the
Harvard Annals, but they do not seem to have arrived
in England as )'et. When they arrive they will be
studied with great interest, as likely to throw much
light on the perplexing problems which these distant
satellites present to us.

Mimicry among Insects.

By Percy Collins.
It has been said tliat the strongest testimony to the
value of warning coloration is afforded by the like-
ness which harmless insects sometimes bear to dan-
gerous or noxious ones. Such instances are generally
referred to as " mimicry," although the title is also
(though somewhat unwisely) employed in descriptions
of deceptive appearances which should really be spoken
of as protective resemblance. True mimicry, accord-
ing to the accepted scientific meaning of the term,
consists in the external likeness of a poorly-protected
creature to a well-protected one, whereby the former
is enabled to share in the immunity from attack en-
joyed by the latter.

Not infrequently, the young student finds some
difficulty in comprehending fully the theory of mimicry,
when first the subject is presented to his mind. In
such cases a direct appeal to nature is usually more
fruitful than abstract explanations. Let us, therefore,
take an actual instance of mimicrv among British
insects.

The poplar clearwing (Scsia apiformis), in its general
appearance, is exceedingly unlike a tvoical moth. Its
wings are transparent, tinged with yellow ; its thorax
is brown, with a square patch of bright yellow on each
side in front ; its abdomen is yellow with a brown belt
near the base, and another near the middle ; while its
legs are deep orange. It has, moreover, a general
aspect of trimness and alertness very unusual among
the Lcpidoptera.

But although the poplar clearwing is unlike a moth,
it is very much like a hornet. Indeed, it is doubtful
whether a person unversed in the study of entomology
could distinguish between the two insects merely by
ocular examination. Yet a hornet and a moth belong
respectively to totally distinct orders of insects ; what,
therefore, can be the meaning of the close external like-

240

KNOWLEDGE & SCIENTIFIC NEWS.

[October, 1905.

ness which exists between them ? Not many years
a -o, entomologists — while perfectly familiar with the
fact of this remarkable resemblance — were quite at a
loss to account for it. To-day, in the theory of
mimicry, we find a very plausible explanation of the
problem.

The hornet is one of those creatures which have
been provided by nature with very adequate means of

1. Th: Hornet trttpa erahro\

2. The Poplar ClearwIOK ^Sell^a apiformiMi.

self defence. It is capable of inflicting painful and
even dangerous wounds with its poison-injecting
sting ; and, as a warning to its would-be assailants, the
hornet has been provided (probably through the agency
of natural selection) with a distinctive livery of
orange and dark brown. In a former article it was
shown that such a livery, possessed by a well-protected
species, prevents a vast amount of unnecessary
mortality because, by its means, insectivorous
creatures are able to determine without " experimental
tasting " what insects may be eaten with impunity.
Bearing this in mind, it is not difficult to realise that a
perfectly harmless insect whose colours and form
agreed with those of a well-known harmful one,
would be likely to share in the immunity enjoved by its
prototype, (iranted that the likeness were sufficiently
close, ins<;ct-eating animals would be completely de-
ceived by it.

In the case of the Sesia and the hornet, there is little
doubt that this is what actually occurs. The former
insect flourishes on the evil reputation possessed by the
latter, being mistaken for a stinging insect by the
birds, which would be only too glad to cat it did they
know it to be a harmless moth. A "lance at the ac-
companying drawing from nature will give the reader
an idea of how closclv the.se two insects resemble one
another in general appearance. The size and shape of
its body and wings, together with the arrangement of
its colours, combine to give the moth a hornet-likeness
which is truly astonishing when the wide differences of
structure and habits existing between the two insects
is taken into account.

The order Hymennpitra supplies types for mimicry
in many parts of the world. Indeed, it may be claimed,
in a sense, that the males of the various stinging
species are really mimics of the females and workers.

For the drones possess no stings, and their " warning
liveries " cannot, therefore, have the same direct
significance which they possess in the case of the
females and workers.

Species of Hymcnoptera are constantly found to be
mimicked by species of Diptcra in a most perfect man-
ner. Field entomologists in ICngland will be familiar
with the bee-flics {Bombyliin) which, in their hairv
covering, general appearance, and the manner in which
they hover about a flower, ha\c all the characteristics
so familiar in a bee.

Species of Hcmiptera have been found bearing a
striking resemblance to ants, with which insects they
company. It cannot, however, be said in what manner
— if at all — the bugs are benefited by their likeness to
their companions.

Here it may be said that the mere fact of one insect
resembling another to a marked extent docs not neces-
sarily constitute a case of true mimicry. There is
little doubt that a similarity of habitat and environment
conduce, at times, to a similarity of form and colour-
ing. Indeed, there are cases on record of insects in-
digenous to countries extremely remote one from
another, which might well be put forward as examples
of mimicry were a similarity of form and colouring the
only test.

Even in the case of similarly coloured insects living
in the same country and under similar conditions, the
mere fact of a mutual likeness must not be regarded as
proof of a mimetic relationship. The two British
beetles Triplax aenea and Tclratonta fuiigorum, which
belong, the former to the Clavicornia and the latter to
the Tieteromera — two widely different families — would
be indistinguishable to the novice. Each has a red
thorax and bluish black elytra ; each, too, may be found
on fungoid growth on decaying trees. Yet, so far as
the writer is aware, there is nothing known about the
life histories of these insects which would justify the
assumption that one is a mimic of the other. It is
quite conceivable that a similarity of food, surround-
ings and habit may have brought about this strange
likeness in colour and form. To establish a case of
true mimicry it is necessary to show that one of the
insects concerned — the prototype — possesses some
dangerous or noxious quality which renders it dis-

L>tlu^ii /ei ruffinfa.

tasteful to the majority of its enemies ; and that ilic
mimicking species, by agreeing with the special type
ol warning coloration concerned, is able to share in
the immunity.

This by way of warning to the young observer,
whose enthusiasm might lead him to draw conclusions
unjustifiable by fact. At the same time, it cannot be
doubted that many very perfect instances of true

October, 1955 ]

KNOWLEDGE & SCIENTIFIC NEWS.

241

mimicry exist. Keeping still to the Hymenoplcra,
which on account of their stings constitute such ad-
mirable prototypes for mimicry, we find that several
European beetles — such as Emwi liirius. and Truhnis
fasciatus — have a striking bee or wasp likeness,
especially when on the wing. The well-known "Wasp"
beetles, too, of the genus Clytus, are probably to be
regarded as instances of mimicry. The most inter-
esting case of a beetle mimicking a large Hymenop-
terous insect, how^ever, is perhaps that of Esthesis
fcrruginca, a representative of the Lflngicornia, from
Australia. This species has the orange and black
banding so commonly associated with the possession
of a poisonous sting. Moreo\er, its elytra have be-
come so much shortened as to be quite inconspicuous
— a character very rarely seen in the group to which
the insect belongs. In this way the wings, whether
in use or folded above the abdomen, are fully exposed
to view, just as they are in the case of a wasp or a
hornet. Of course the beetle has only two flying wings,
whereas Hymenopterous insects have four. This,
however, is a detail which does not strike the casual
observer ; moreover, the wings of the beetle are pro-
portionately broad, while there is a lobed portion of the
hide margin which has much the appearance of a
second pair of wings.

The above is an exceedingly interesting case of true
mimicry ; yet among the Lcpidoptcra we find numerous
instances which are still more striking. No butterfly
or moth possesses a sting, but many species are ren-
dered objectionable to insectivorous creatures on
account of their noxious juices ; and such species are
commonly found to be warningly coloured. Thus
they constitute prototypes for mimicry. There is,
for example, a distasteful butterfly common in the
Indian region of the Eastern Hemisphere, known as
Damns mclanoides, the colour pattern of whose wings
is mimicked bv a number of other butterflies belonging
to several distinct families, and by at least one moth.
The Daiiais has pale wings, striped and bordered with
black ; and this design is followed, often with sur-
prising accuracy, by its mimics. .\ glance at the ac-
companying photographs, which show Danais
mclanoides and seven of its mimics, will bring this fact
home to the reader. Moreover, he will see that the
seven butterflies concerned represent no less than five
families, viz., Papilioidfr^ S ymphalidcr, Pieridcr,
Elymniida and Salyridn-.

Not infrequently, a mimicking species differs in an

extraordinary degree from the typical species of the
family to which it belongs. This difference is most
striking, perhaps, among some of the South American
butterflies — notably the genus Dismnrphta. This
g-enus belongs to< the Picrid(F. — a family numbering
among its members all our well-known " white "
butterflies. Its typical .South .American representa-
tives differ comparatively little from their relatives
in other parts of the world. But only an entomo-
logist of experience would recognise Vnmtrphia or/sc
as belonging to the same family. Indeed, it was
an actual confusion of such species as this with their
pi-otot\pes which suggested to the late Henry Walter

Bates the train of thought which led ultimately to his
suggesting the theory of mimicry. Among the
butterflies which he brought home from South America
there were species which, in the hurry of collecting,
and packing, he had placed together ; but which sub-
sequent examination showed to be widely different in
structure.

It may be asked : By what process can this insect
{D. irisc) have come to differ so remarkably from the
typical members of its family, as to resemble the dis-
tasteful type represented by Methoma confusa ? At
first thought, natural selection, powerful agent though
we know it to be, seems incapable of achieving such a
result. But we must remember that we are looking
at the work — not of tens or hundreds, but possibly of

1. Dcinau jiiehin

2. Papilio epycides.

3. Painlio mac^veu-:.-i

4. Papilio xenocUs.

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iliKi 1 1 Ml I •|ip(iMiiJ(il('i'i, fiiiil llic (iplri.'il ««»r«l vj'.xH Niii(lii-il

111 (Ml ■lll^; mI N-Kiys, Wllicll WCCi' ((MMIfl tolir- (,'ivCII l>Ul

iMiiiM I ijii I itillv ll'l^Ml riM liiln porlionN, M, Cli.-irpi'tilici

|MIMMi|ill III bliHIr blill IMl)ll< hlril<ill){' ri|li-rMl;ilioMs. Mr
Hf|it ImI Id iM(|Miu' wIm'IIuT liici't* \h II N|)('(ilic icinlnicr-

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IIm' t>HMr'>>|l|iMlliMU MI'IMMIh irllllCN Mil' |llivsirill cxcitiint
I •l|i>llilii III tilling ll|iiin llii'in III' (Iririilx's in ii roil)
Miiiiili iilliMI III llli< I'lrlirli Ariiili-iny nl Sricix-ct, in
M.i( III |i|i«| \')Mir, l\i»w lii< liniiid lliiil wlini ii phitspliorrN-
< I III '4 H'lMi ih inniti' liii\ 111^ lor iiii'ii' ;in odoiil'i'ioiis siil>~
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II. ilir iiri viiUH I niliivh, cMpiM'iidly near cnliiin of llicni,
vnIiIiIi (ii.«\ |i(i lidli'il olliirloiv poiiils, Similiii rlTfcls
oil III ill lliortitir ol lliti oi'tiitDs i>f visi(>ii, nnd the rrlatnl

October, 1905.J

KNOWLEDGE & SCIENTIFIC NEWS.

^43

nervous centres when a screen, with a luminous base, is
used. It is inferred from the experiments : (i) That
the sensorial ner\-ous centres are specifically different ;
(2) that there is a certain adaptation, not only between
physical ag-ents and the sensorial agents destined to
receive them, but between those ag'ents and the nervous
centres which perceive them after reception by the sen-
sorial agent ; (3) that there are certain common pro-
perties implying analogy of nature, between sensorial
excitants and the peripheral or central nervous
organs destined for their perception, since they show,
by the sort of specific resonance referred to, analogous
emissive properties.

The existence of X' rays first noticed by M.'Blondlet,
and referred to above, seemed to be confirmed by M.
Charpentier, v.ho published an account of some obser-
vations of his own, which showed that N' rays exert a
physiological action which is the inverse of that of the
N-rays. Thus, they cause a decrease of the sense of
smell, instead of increasing it. as do the X-rays.

The contributions to the study of the X-rays, and the
still more mysterious N' rays form, indeed, in France,
a complete literature bv itself. Perhaps nothing quite
so extraordinary- has previously been made known.

A very noteworthy fact, however, is this, that numer-
ous practised obsersers, including some of the most
eminent scientific men of the day, have been quite
unable to observe the effects of these X-rays, even
when looking for them under conditions identical with
those under which they were recorded by the obser\-ers
in France.

We have thus next to notice some ven,- important
criticisms upon the whole series of published facts, and
especially is it necessan.- to consider the remarks of
Dr. Lummer, the German physicist, who commented
upon M. Blondlot's researches in a paper read before
the German Physical Society in Xovember, 1903.

Dr. Lummer, without wishing, in the meantime, to
ous practised observers, including some of the most
that a whole series of Blondlot's researches may be
almost completely imitated without using any source of
radiation, and that the changes in form, brightness,
and colour of the surfaces obser\-ed by Blondlot may be
explained by what goes on in the eye itself, and by the
competition between the rods and cones of the retina
in vision in the dark. Kries explained the function of
the cones as being our apparatus for brightness fit for
distinguishing colour, and the rods as blind to colour,
and forming our apparatus adapted for darkness. Be
fore the cones perceive coloured light, the rods produce
in the brain tlie impression of colourless brightness.
The fovea centralis contains cones only, while the rods
predominate at the periphery of the retina. Thus, in
direct vision (foveal') the rods are excluded, and only
come into action in indirect (periphcnil) vision. With
small brightness these two portions of the visual ap-
paratus come into sharp contest, and if the dimness is
great, the colour-blind rods prevail, and everything ap-
pears grey. Dr. Lummer. in his work on " The grey
glow and the red glow," explains on this theor\- the
sudden chattg'es which occur when a body is obser\"ed
in a dark room, and its temperature steadily raised.
The sudden change from dark to grey, and, again, the
sudden increase from the grey glow to the red glow,
are due to the successive stimulation, first, of the retinal
lods, .and then of the retinal cones. Shadow^' vision
i? produced when the fovea centralis is not stimulated,
and n sheet of heated platinum, for example, observed
in the dark. A source of radiation is perceived, but not
c'early seen, till the cones also are stimulated, which

occurs at ab«}ut 500° C. In some of Blondlot's experi-
ments the case of the shadowy vision thus described
.•■eenis io be reproduced, and the effect has been shown
to an audience. .\ dull, glowing platinum plate is first
seen by extra foveal parts of the retina. On interpos-
ing the hand or .a lead screen, the gaze is limited and
fixed, the foveal part of the retina is brought to bear,
and the actior, of the rods excluded. The tesult is that
the plate appears less bright and more red-coloured.
Time and eft'ort are .-equired for this change, as in tlie
exoeriments described by Blondlot. The phenomena
are thus probably subjective to a large degree, or may
be described as due to objective occurrences in the
retina.

.\n e> tended series of observations were made in the
physiological laborator]i- of the L'niversity of Glasgow
with the object of confirming Blondlot's observations,
but the results were uniformly negative. Prof.
McKendrick and Mr. Colquhoun describe their experi-
.ments, which were carried out with the help of seven
observers who were trained to accujate work. On ob-
serving a small fluorescent screen in the dark these ob-
servers noticed apparent changes of brightness when
there was no contraction of muscle, and no question of
X-rays reaching the fluorescent patch. When the ob-
servers were asked to look into the distance beyond the
bright spot, and report on the brightness of the screens,
the result was very noteworthy. TTiey all reported,
without exception, that the brightness of the screens
was constant, and that muscular contraction made no
difference. In this case the accommodation of the eyes
for near vision was relaxed. It is suggested that there
is a difficult}- in accommodating for the fluorescent
circle observed, and that there is a wavering movement
of the cilian.- muscles, and, perhaps, also a wavering in
the size of the pupils. Besides this, it should be noticed
that Heinrich, some time ago, found that the pupil
dilates when examining an object situated in the field
of indirect vision, and that it dilates still more during
a short mental effort. He found also that, on direct-
ing attention to an object in the field of indirect vision,
the ciliary mu.scle relaxes, thus diminishing the curva-
ture of the crystalline lens, and this change is very
marked during mental calculation. Prof. McKendrick
suggests that the mental condition of some observers in
a state of expectancy may react on the intrinsic
muscles of their eyes, and thus they may see what they
think they should see.

Prof. K. W. \\'ood, of -America, when on a visit to
Europe in the autumn of last year, spent some time in
examining the methods of obtaining the X-rays in one
of tlie laboratories on the Continent, where the mani-
festations of the new rays were announced as verv dis-
tinct. He failed, however, in obtaining anv evidence
which satisfied him that these rays really existed.
.\fter spending some hours in watching" and taking
part in all the various experiments by which the pro-
perties of the X-rays are supposed to be indicated, he
left the laboratory with the firm conviction that the
few observers who have obtained positive results have
been in some way deluded. The interposition of the
hand in the path of the rays seemed to make no differ-
ence in the brilliance of a small electric spark, which
was supposed to be acted upon by these ravs, though,
according to M. Blondlot, the cutting- off from the
spark of the X-rays which takes place when the hand is
interposed makes a distinct difference in its brightness.

Prof. ^Vood regards the photc^raphic method 01
showing an objective effect due to the rays to be quite
illusory. The effects of refraction bv an aluminium

244

KNOWLEDGE A: SCIEXTIEIC NEWS.

[October, 1905.

prism he found to take place, according to his colleague
working with him in a dark room, whether the prism
was in position or not. A piece of wood seemed ti
have the same effect as a file in acting upon the retma
to increase its sensitiveness to N-rays ; and the re-
moval of wood or file had no influence in stopping the
apparent effects which continued to be observed by the
experimenter when these exciting objects were re-
moved. On the whole, I'rof. Wcxxl, who has himself
observed and recorded so many interesting results in
his experiments on light, left the lalK)ratory, which was
one of the homes of the N-rays, with the firm convic-
tion that all the changes in distinctness of sparks, and
variations in luminosity of screens by which the exist-
ence of X-rays has been thought to be proved, were
purely im:iginary.

Other experimenters, both in England and America,
as well as in Germany, have severely criticised the
methods adopted and the results obtained. No satis-
factory reply to these searching criticisms has yet been
forthcoming, and it would appear to be highly probable
that the long series of researches carried out on these
mysterious new rays must be regarded as forming a
chapter in the history of human error.

The Cairo ZoologicdLl Gardens.

.\ L.\Ki.E luirnijtr ol animals havi- rcci'nllv been .idcicci
to this collection as the result of some members of the
staff, including Capt. Stanley Flower, making an ex-
pedition to the Sudan. The new additions include
three .African elephants, 15 -Sudanese lions, two addax,
one QZIians wart hog, two Senegal or saddle-billed
storks, and six crocodiles, and amount in all to 129
animals.

Where to be Safe from
E^arthqviakes.

By BEKiisioKD l.\e;R.\.\i, H.A., l-.C.S.

The terrible effects of the eartlK|uake in Calabria,
lialv, last month, together with the equally destructive-
shocks in India, and the disturbing tremors felt in
Yorkshire and Lincolnshire in .April last, must have
caused more than one person 10 inquire where he must
live to be safest from these calamities, against which
the precautions of man arc so utterly futile.

Many years ago Dr. Mallet made an exhaustive in-
vestigation of this question, and his work, when pro-
perly studied, brouglit to Hght a fact of fundamental
importance to the linghsh people, i.r.. No place in the
world can claim an immunity from these terrestrial
disturbances, but, nevertheless, England is less liable to
iiif-fer seriously from the cfjeels of a shoek than any
other European country.

A review of the following facts, which he, and others,
have formulated, will confirm the reader in the accept-
ance of the above gratifying assurance. Mallet pre-
pared a map of the world, coloured so as to show where
earthquake shocks had been experienced. The colour
Vi'as deepened at those localities which had suffered
most or had been subjected to a greater number of
upheavals.

When this map was finished and studied, it revealed
the following important facts : —

(i.) The bands of the darkest colour run along
those mountain chains on which volcanoes occur. This
would seem to suggest that volcanic eruptions and
earthquake shocks had some connection.

(2.) The .-ibove b.inds (r.illed "seismic bands")
generally follow the lines of elcwilion tliat mark and

Within the black band earthquakes are both fre(|iicnt and severe.

October, 1905 ]

KNOWLEDGE & SCIENTIFIC NEWS.

245

divide the great oceanic and terroceanic basins of the
earth's surface.

(3.) Earthquakes may become visible at any point
on the earth's surface, but the greater effects are con-
fined to those areas in the vicinity of the lines of vol-
canic activity.

Prof. G. Darwin also' prepared an "earthquake map,"
which shows (see Fig.) a broad band completely en-
circling the world, with which area earthquakes were
both frequent and severe.

This band, as will be seen, encloses the following
countries : — Southern Europe, the Mediterranean area,
Asia Minor, Syria, Persia, Northern India, China,
lapan, across the Pacific to Central America and the
West Indies, then through the Atlantic to the Azores,
Teneriffe, Portugal, Spain, and North-West Africa.

There are other Seismic bands, such as those of the
Andes and the Malay Archipelago, but these may be re-
garded as siiort ofl'shoots of the "great seismic band ;"
these latter, it will be noticed, are at right angles to the
line of general disturbance.

If we review the list of earthquake shocks that have
taken place within recent years, we shall see how they
confine themselves to areas that come within the black
band marked out on the map.

1868. — Peru and Ecuador. When four cities were

destroyed.
1875. — San Jose (Colombia). Earthquake so sudden
that the people had no time tO' escape, so
that many thousands of lives were lost.
1903. — Turkestan. Similar disaster to that of San

Jose.
1904. — Macedonia.
1905. — Albania.
1905. — Northern India, Lahore. Terrible loss of

life.
It is known to everybody, that when a shock occurs
in any particular locality, it develops an "earth wave,"
which traverses a greater or less portion of the globe
according to the magnitude of the original disturb-
ance. In fact, it is this wave which, in most cases,
produces the terrible effects about which we read.

This wave travels easiest and quickest through solic
rock. It has been calculated that it traverses granite
at the rate of 1,665 feet per second, which is very much
greater than the velocity with which sound travels.

Through shattered rock it goes at the rate of 1,306
feet per second, through slate 1,089 f^*^* P^f" second,
and through wet sand with a velocity of 825 feet per
second. The deeper the rocks are, the quicker does
this wave get through them.

Of course, it travels very much slower through water.
Observations on the velocity of the sea wave, which
invariably accompanies the earth wave, show that
it depends upon the depth of the water through which
it has to pass, going much quicker through deep
water than through shallow. When it is remembered
that this sea wave is some twenty feet in height, and
its velocity may attain six miles a minute, it can be
readily imagined that a sea coast with deep water in its
immediate vicinity is not a desirable locality during an
earthquake.

A very curious anomaly has Ix'en obser\ed in the
study of this subject, namely, that the region immedi-
ately above the centre of the disturbance suffers only
very slightly from its effect. The seismoJogical term
for this area is the "Epicentrum."

Suppose the centre of the disturbance were twelve
miles below the epicentrum (measured perpendicu-
larly), then the region which would be most seriously

affected would be twelve miles distant in any direction
from the epicentrum on the surface.

Of course, the whole region is affected, but the
serious effects are not apparent until a region is ap-
proached which is as far away from the epicentrum as
the latter is from the internal centre.

It has been estimated that the origin of an earth
quake very rarely occurs at a distance of more than
30 geographical miles below the surface, but, as has
been stated before, the earth wave has practically no
limit.

The surface effects of an earthquake are more de-
structive when it traverses soft rocks, because the
cracks that are produced at the surface are kept open
for a longer time, and allow the soil to slip, and the
buildings to subside ; whilst in the harder rocks, fis-
sures are formed which are narrower, and will close
more quickly, causing, thereby, far less displacement.
Perhaps the greatest destruction is caused when the
waves travel from compact rocks to loose and soft ones.
In these cases complex reflections and reverberations
of the shocks ensue, producing the shivering of the
surface of the land, which, of all disturbances, is the
most to be feared, and the worst to be experienced.
This is undoubtedly what has happened in Calabria,
where the surface rocks are soft and loose, while the
lower ones are hard and compact.

If the angle of emergence of the wave is small, the
difficulty which the wave experiences in passing from a
compact rock to an overlying soft rock is such tha" a
very small shock is felt. This is of especial importance
and interest to England, since our country is so far re-
moved from the areas of intense seismic activity that
the angle of emergence is ahvays low, added to which
the surface of the land is composed mostly of soft rocks;
and this is the reason that, when a severe earthquake
takes place in Europe or North-West Africa, it is usu-
ally felt in .Scotland, where the surface is almost uni-
formly of solid rock ; the same shock being scarcely
perceptible in England.

Should the reader then live in fear of being swallowed
up by the earth, and should he be fortunate enough 10
be able to choose anv part of the world for his abode,
he would have to consider (i) his proximity tO' either
active or extinct volcano, (2) his proximity to lant'
bounded by shores with ai high gradient, (3) the nature
of the strata beneath the surface, and, lastly, the
distance from any other earthquake region, having a
proper regard as to whether there was a relatively
small depth of soft rock on a bed of granite, or other
solid substratum.

The Birkbeck College, Bream's Buildings, Chan-
cery Lane. — This Institution, which has now completed
82 years of educational work, will commence the new
session on Monday, October 2nd, when the Right Hen.
.Sir Edward Fry will give the Opening Address, at 7.30
p.m. The Day and Evening Courses of study comprise
the various branches of Natural Science (Chemi.'-try,
Physics, Botany, Zoology, Geology, etc.). Mathe-
matics, Latin, Greek, Modern Languages, Economics,
Law, Logic, and Commercial Subjects. Courses con-
ducted by recognised teachers of the University pro-
vide for the l^xaminations of the Lhiiversity of Lon-
don, in liu- h'aculties of Arts, Science, Co'mmerce and
Law. I'hc icport for the last session shows that during
the year 84 students passed sO'me University Examina-
tions, while a large number gained successes at various
public examinations. Special classes prepare for the
Conjoint Board and Ci\il Service Examinations.

246

KNOWLEDGE & SCIENTIFIC NEWS.

[October, 1905

The Total Eclipse.

Accounts froiTi all Sources.

Ir had been our earnest desire to have given an ac-
count, in this number, of the general resuUs obtained
by each of the principal parties which left Hngland for
the purpose of observing the eclipse. But in some
cases the observers prefer not to publish any pre-
liminary account until their full report is presented,
while others have been too busy since their return to
render any narrative of their doings. 'llic following
accounts are, therefore, only a brief summary, which
we hope to be able to augment in future issues.

The most westerly expeditions were stationed in
Ladkador, but it seems that clouds completely ol)-
structed the view in these districts. Sir William
Macgregor, the Governor of Newfoundland, was at
Cartwright, where also was a party from the Lick
Observatory. Another party of Canadian observers
under Dr. King, was at Hamilton Inlet, and Mr. E.
\V. Maunder was also there.

.\l Burgos, in Spain, the overcast sky greatly im-
peded the view, but photographs of the corona were
secured through rifts in the clouds.

The party at Oroi-esa, on the East Coast of Spain,
which was under Prof. C:dlendar, of the Royal College
of Science, was unfortunately entirely precluded from
making any observations on account of the clouds.

Mr. |. Y. Buchanan, F.R.S., however, at
Torreblanca, only a few miles further north, had the
luck to see the eclipse in a quite clear sky. He
describes the corona as being very bright, and with
clearly defined edges, like fortifications. The light
generally, was so great that he was unable to detect
any stars except Venus. The prominences, described
as of violet colour, were well seen at the beginnings and
end, but were not visible at the middle of totality. This
should give a practical clue to the height of the
prominences.

In the Balearic Islands various conditions of
weather prevailed. Near Palma, the expedition from
the Solar Physics Observatory had taken up a good
position. The party, under .Sir Xorman Lockver
included Dr. J. W. S. Lockyer, .Mr. C. P. Butler,
Mr. Howard Payn, Mr. F. McClean, and a number of
officers and men of H.M.S. " \'enus." Though the
weather conditions were by no means perfect, since
clouds moved perpetually over the sky, yet .some fairly
pood results were obtained with the many instruments
provided.

In the centre of the town of Palma, several English
astronomers, including Mr. Crommelin, had estab-
lished themselves on the roof of the CJrand Hotel.
Here, too, clouds obstructed the view to some extent,
lillhough fairly gofKl observations were made through-
out the perifKl of tf>tality. But in f>ther directions on
the island, the eclipse was absolutely invisible through
clouds. .Shadow bands were well observed. Within
a few miles of the town severjd ob.servers had a clear
sky.

Several British observers, unwilling to experience
the mysteries of out-of-the-way .Spanish hostclries,
and long railway jriurneys, Uxtk the mf>re cf)mfortable, if
less business-like, method of going in larg-e steamers.
Two liners, timed to be well within the limits of totality
at the moment of the eclipse, had arranged to heave-to

to enable passengers to ha\e a good Nievv of Uie pheno-
menon. In both cases the atmospheric conditions were
fairly g'ood, and if no exact or speriallv valuable obser-
vations were m.ide, at all events the ol;servers were well
satisfied with what they saw. On board the "Orlona"
the prominences were well seen, ;md described as of
" rose-colour " with bases of yellow, and only noted on
one side of tlie sun at a time, llie corona, of " a soft
pearly blue," had streamers projecting about two dia-
meters, two pairs '" above and below " the sun. \'enus,
Ivegulus, and .Mircurv were reported as being visible.
The P. and O. steamship " .\rcadia " also carried ,
party provided with small telescopes, two spectro-
scopes, and many cameras. The vessel hove-to near
the Columbrclcs Rocks, south of Majorca, in perfect
calm. 'Hiough clouds passed over the sun, there were
intervals of perfect clearness. Baily's beads were .seen,
as were the shadow bands. The conclusions were that
the corona was very compact, and very bright, and of
a silvery hue. Only one ray stretched out conspicu-
ously from the cr.rona, but four cr five minor streanuM-s
also existed. The prominences were said to be paler
than usual. The thermometer fell from 82.4° to 72.5".

Perfect weather seems to have prevailed at Phillip-
viLLE. in Algeria, whither cur Solar Physics Observa-
tory party was originally destined to go.

At GuELMA aJso, the conditions were most favour-
able. Here Mr. Newall made many successful obser-
vations with the g^reat spectroscope from Cambridg-e.
M. Trepied, director of the .Algiers Observatory, was
also installed at this place. Tlie corona was here re-
ported as being very bright, not extensive, and uni-
formly distributed round the sun. llie red protuber-
ances were w-ell seen, as were Baily's beads. Mercury,
Venus, and Regulus are reported to have been visible.
Thirty-one photographs were taken by the .Algiers Mis-
sion. The temperature fell during- the eclipse from
33° to 28" C. Shadow bands were well observed.

.At Sfax, in Tunis, was the party from Greenwich,
under the .Astronomer Royal, assisted by the crew ol
H.M..S. "Suffolk." A French party was also here, under
M. Big^ourdan. Though partially cloudy, the eclipse
was fairly well observed and photographed. The
corona, as seen here, is reported to have been of the
characteristic maximum type, with streamers extending
to as much as two diameters from the disc, and "of a
rosy colour.'" 'Hie following account appeared in the
Times : —

" The day of eclipse was by much the worst day that
was met with. It broke cloudy, cleared a little in
the forenoon, but left a nasty haze ;ibout the sun that
was reinforced as the time approached by light de-
tached clouds blowing from the north-west. The sun
was never hidden for more than a few seconds, but
it was unpromising for the big telescopes. .As the
moon crept over the sun's face the temperature, which
had been at 90 deg., fell slowly to 84 deg^. 'Iliere was
no sense of chill in the air. The party of observers
was reinforced by ofticcrs and men from the Suffolk,
told off for w.'ilchiiig attend.int phenomena, for count-
ing seconds from a metronome, or other help. 'Hie
light grew weird, and dancing b.'mds of shadow were
seen upon the ground and walls. \'enus shone out,
and soon afterwards Arcturus. -Sir William Christie
watchefl the diminishing crescent of the sun's disc on
the groiiiul glass of the Thompson camera, and called
out " Stand by" 20 seconds before the disc should dis-
appear. All was ready. Then f)ccurred a delay, im-
accounlable at the moment, but clear enough .after-

3UPPIEMENT TO " Knowmeoe & SClSKTlFrC NEWS," OclobeT, 1905.

THE TOTAL ECLIPSE OF 1905,

From a drawing by Major Baden-Powell at Palma.

October, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

247

wards. There seemed no definite beginning lo the
ecHpse. The crescent never wholly disappeared, or,
rather, it merged into a magnificent group oi promi-
nences spread over an arc of almost 30 degrees, near
the spot where the last of the sun's true disc was seen.
They must have been of immense height, and it seemed
at least 30 seconds before they were hidden by the ad-
vancing moon. At the same time, gradually too,
emerged the corona. Observers who have seen many
eclipses say it was but a poor corona. To others it
did not seem so. In place of the sun's crescent, an
inky black disc hung in the sky, with a great span of
rcsy prominences east of its vertex, and at all other
parts of the circumference streaks and streamers of
pale but defined substances set v\ith the strangest irr gu-
larity, brilliant round the edge of the disc, and lost to
the eye some two diameters distant. Many observers
saw a rosy tint in it. Otfiers called it a pure silver or
aluminium grey. It was most unmistakably of thi
type associated with sun spot maximum. Many stars
were visible, though the sky was never very dark.
Too soon its 200 seconds were gone, and with amazing
brilliance the sun's disc began to reappear. Nothing
remained but tO' collect results, and tO' ascertain how
much the indefinite beginning had spoilt the plan. It
is hoped that it interfered but little. Most observers
took successfully as many as seven photographs out of
eight. How far the haze and diffused light of the
sky may affect these can be answered only when the
plates are developed at Greenwich."

In Tripoli the eclipse was observed under very
favourable circumstances, as described by Prof. Todd
in Nature. The .American expedition from .Amherst
College set up their instruments at the British Con-
sulate. Observation on the shadow bands were here
successfully made. They were " seen as early as ten
minutes before totality, and had many remarkable
and pronounced peculiarities. They were wavering
and narrow, moving swifter than one could walk, at
right angles tO' the wind, their length with it, and wax-
ing and waning five times during the eight minutes
preceding totality." -A disc eight inches diameter was
put up at a distance of 35 feet, in order to observe
the outlying streamers of the corona, but nothing was
seen protruding beyond the disc. Totality, predicted
to last 3m. 9s., was only 3m. 6sec. in duration. "Baily's
beads'' were well shown in photographs by means of an
orthochromatic screen, and other photographs were suc-
cessfully taken. The corona was ''not impressive,"
being evenly developed, with no' long streamers. There
were also parties in Tripoli under Prof. Millesovici, of
Rome, and M. Liberd, of Paris.

•At .AssuAN, up the Nile, were stationed three national
expeditions — British, American, and Russian. Prof.
Turner, of Oxford, assisted by Mr. Bellamy, made
special observations on the light of the corona. The
Times reports: — "The British party, with invaluable
assistance from Captain Lyons and the officers of the
Survey Department, obtained five ordinary exposures
with an astrographic telescope, besides one with a
green colour screen and one enlargement, six photo-
graphs polarised by reflection in a horizontal plane, and
two in a vertical plane. Mr. Giinther, of Magdalen
College, Oxford, obtained six plates with a Goerz lens
for comparison with similar plates taken in Labrador.
Mr. Reynolds's 120-ft. reflector was mounted under un-
foreseen difficullies, at short notice, with the able assist-
ance of Mr. Keeling." The party from the Lick Observa-
tory, under Mr.Hussv, was equipped with good photo-
graphic instruments, some being exactly similar tc

those used by the other party from the Lick Observa
tory, who were to^ observe the e<"lipse in Labrador.
These two' stations being situated so far apart that the
times of totality differ by two a.nd a half hours, it was
hoped that any change in the corona during this period
might be detected. Egyptian skies are proverbially
clear, but there was a certain amount of haze over the
sky, which detracted somewhat from a clear view of the
corona. The change of temperature was very slight.
The corona appeared small, with its longest streamer
to the south-east, about two diameters or less in length,
and three shorter ones.

THE SUPPLEMENT.

The coloured plate should convey to those unfamiliar
with total eclipses a g-ood idea of the general effect.
It can well be supposed that it is impossible to make a
really careful drawing during the three brief minutes of
totality, and all that is possible is for the artist to
make some rough and hurried notes, and after the
event is over, tO' try to depict the same from memory.
L'uder these circumstances, the details portrayed must
not be taken as being exact. Photographs alone can
give us the true position and dimensions of the promi-
nences. In this case, too, the shape of the corona is
not to be taken intO' account, for two reasons. First,
in order to give some idea of the intense brilliancy of
the prominences, and of the innermost part of the
corona just around the moon's disc, it has been con-
sidered necessary to darken the rest of the picture.
Secondly, the observations at Palma were marred by
thin clouds passing in front of the eclipse, so that the
fainter streamers of the corona were not visible, and
only an evenly marked band of white light seen around
the moon. The prominences, nevertheless, were very
clearlv seen through a small telescope with an 80-power
eyepiece, although it is quite impossible to adequately
represent in a drawing the extraordinary luminosity
and splendour of these gorgeous flames.

[Just on going to press we have received an interesting account, which must
he deferred till next month, from Professor Marcel Moye, of Montpellier
University, who saw the eclipse very well from Alcala de Chisvert on the East
Coast of Spain ]

TO THE EDITORS OF " KNOWLEDGE."

Sirs, — ki Burgos last week several people, shortly after the
eclipse, told me that they had seen the fourth of the five
splendid prominences visible on the east limb of the sun,
together with the Cromosphere between the third and fifth
prominences (all counting from the top downwards) of a dis-
tinctly green colour, and it would be very interesting to know
if others of your readers could confirm this observation of
what would seem to have been a coronium prominence ; to
me they all appeared of the usual cherry-red colour, this
fourth one being, perhaps, a little paler than the others.

The Corona was only faint compared to the glorious one we
saw at Ovar in igoo.

Yours truly,

C. Nielsen, F.K.A.S.

Hartlepool, Sept. g, 1905.

The HoLrberv Lectures.

This series of lectures will be delivered at the Royal
Institute of Public Health, Russell Square, by ProL
Thomas Oliver, M.A., M.D., LL.D., etc.on October 10,
12. and 17, at 5 p.m. The subject will be " Some of the
maladies caused by the air we breathe in the Home,
the Factory, and the Mine."

248

KXOWLLDGE cS: SCIENTIFIC NEWS.

[October, 1905.

SeaL^veeds :

A Holida-y Pa.per for Field
BotaLHists.

By U.wiD W. Bevax, Scarborough l-.N. Society.

III. -The Green Seaweeds.

The Green Scawec'cls — last yroup of all that ends this
strange, eventful history — the group that lends bright-
ness and cheerfulness to the rocky pools — are closely
allied to the .Algae of the pond and the ditch. In fact,
some genera {Conferva, Vaucheria, and others) have
representatives in both waters.

.All lovers of fresh-water .Alga? know these plants ,
Conferva, with its simple, unbranched row of cells,
Tauclieria, with its branching filament of one large
multi-nucleate cell. TTie green are the lowliest
of the seaweeds. True, some plants of the red
and the brown groups are equally simple in build.
There is practically no difference, except colour.
between the red Callithamnion, the brcicn tctocarpus
(a flufTy, yellow, much-branched plant, two inches high
or more) and the green Cladoplwra (the common "sea
moss"). In each case the filament is a simple row of
cells ; in each case several cells of the filament bear a
branch filament, and this branching is repeated again
and again (Fig. i shows the three plants in the order

?< 60

named). But the green .seaweeds never attain to
the complexity of structure which is seen in most of the
brown and the red— the Wrack and the Chilocladia,
to take two plants haphazard. Ulva, the .Sea Lettuce,
the queen of the green seaweeds, is ,1 mere double
sheet of cells, every t>ne like its neighl«»ur ; Eiitvro-
morfJia, the " sea grass," is the same thing, but is
narrow and hollow — hence the name. Tlie two layers
of cells arc only in contact at the edges, so that the

frond is a closed tube. Ulva and Enteronn rpha are
shown in Fig. 2.

Moreover, it may be repeated that the difference
between the three tribes lies in the reproductive pro-
cess. So that, although the three filamentous plants
mentioned above are buUt alike, we find lelrasforcs in
Callithamnion, tiiale and female elements in Ectociirpus,
while the " sea moss " has its own special method of
reproduction — a process which, once seen, can never
be forgotten. Let us turn, then, to the family arrange-
ments of the green seaweeds.

If the Sea Lettuce is gathered in summer, and a bit
cut out with scissors and placed in a drop of sea water
under the microscope, the protoplasm in .some of the
cells is often seen to be divided into, perhaps, a dozen
rounded portions (Fig. 3). These are the Zoospores.

^'}o^

riir. 2. F'K- 3-

■J'hcy are destined to be discharged, to swim away by
a pair of cilia, and to grow at once into new L'lvas.
There is no union of male and female. I'Lach spore
is fully endowed with the power of germination.

But to sec this wonderful sight under the best con-
ditions, the plant to study is the common sea moss,
Cladoplwra rupestris (not a moss at all), which has
comparatively enormous cells. Fresh, young, light
green fronds should be selected, and a low power
shows that .some of the large, oblong cells have their
protoplasm split up into many .scores of spores. If we
are lucky (or, r.ither, patient), we may see slight rest-
less movements in the mass ; after a while they begin
to slowly slide about amongst each other, till at last
the whole cell becomes a .scene of wild and feverish
excitement. The spores are all now in motion,
Inirrying hither and thither, pushing, jostling, in their
.attempts to liiul a way out (I'ig. (a). In the cntl, a
linv, r(nn)(l jxirc appears :il the upper end r)f the cell
(I''ig. 4b), and f>ut they .-dl rush one by one into the
microscopic <K-ean, put out their cilia, and start off to
see life <>i\ lluir own :iccount. .After a while tliey settle
down, flraw In fhrir cilia, become round — llicy were
pear-shaped l)efr)re- .ind begin the serious business of
life ; thus bringing to an end one of the most fascinat-
in'^ spectacles that the botanist can ever hope to gaze

October, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

249

upon (see Fii,^. 4c, which represents a group of zoo-
spores setthng on a strand of cotton-wool).

If, now, the basin of sea water, with a supply of
Cladophora, is placed aside for an hour or twO', a
green scum appears on it. This is due to myriads of
zoospores, which have come tO' the top, because they
love the light. Pour some of the scum intO' a potted-
meat pot, and place It in the sun. The green all
assembles on the sunny side. Cover it over with a

Fig. 4.

paper in which you have cut a stencil of your initials.
In a few minutes, the tiny green creatures do you the
honour of inscribing those illustrious letters on the
watery tablet beneath. Put a drop of the scum under
the microscope, and illuminate it from below. The
zoospores are seen swimming aimlessly about in their
thousands. But shut off the light below, and throw
a strong light from the side. Instantly the whole
crowd of zoospores turn with their pointed anterior
ends to the light, and there ensues a stampede in that
direction. Now examine the edge of the drop, tO' see
what is going on at that goal to which this crowd of
beings is hastening. P\. struggle to the death is going
on. Hundreds of spores are fighting there for room —
hundreds more fling themselves on the struggling mass,
and numbers perish. .A.nd what we see in this tiny
drop may be seen on many a fine day in summer in the
pools on the shore, where the green scum collects,
always densest on the edge that gets the sun.

The advantage of this love of light is obvious. If
any misguided spore hated the light, it would settle
in the darkest corner of the pool, and, on beginning to
grow, would perish miserably from lack of that food-
stuff— starch, sugar — which it is unable to work up
without sunshine.

It is an exceedingly interesting fact that the brown

Eclocarpus described above produces swimming bodies
which appear to be identical with those of Cladophora
C^'g- .S)- B"' while some of these can grow at once
into new plants, others unite in pairs, and, therefore,
act as sexual elements. Here, therefore, we see the
very beginning of that sexual process which is so
marked a feature in the brown seaweeds and the red.

In Ectocarpus there is no apparent difference between
the male and the female cells ; but inasmuch as it is a
distinct advantage for a cell from which a new genera-
tion will spring to- be possessed of a store of fooa
^naterial, we find in the higher brown seaweeds the
large, inactive female, or ^^^ cell, which has been
already described, while the male cell remains minufe
and active. In the red seaweeds the female organ puts
out a special hair-like cell which projects into the water,
and mterce[)ts the male cell. Tliis last is, strange to
say, destitute of cilia ; it is swept about in the water
until by good luck, it reaches its goal.

.Such are some of the delights that await the field
botanist on ths shore. The seaweeds appeal to his
artistic, poetic, scientific, and speculative faculties. We
see in them life in some of its lowliest aspects, feeling
its way up to> greater utility, greater beauty (which is
more perfect the more it is associated with utility), and
to habits and customs that make for greater success

Fig. 5.

in life. Lilc. we repeat, at its lowest. They have no
eyes, yet they see ; no nerves, yet they feel ; no muscles,
yet they move ; and they exhibit in simple fashion that
passion which, in its highest exemplifications, is
described as "tender." In the protoplasm of which
their bodies are built reside all the possibilities of
life. Our own bodies are built up of and by proto-
plasm ; and we ourselves can do very little more than
the seaweeds that dwell on our shore.

Answers to Correspondents,

.V;s. ]oUy. — Reflected Sunlight. — The light of the sun.
which is estimated to be some 3^ times as bright as that of
an electric arc light, is so intense that when reflected off
the surface of the moon it causes the latter to "shine."
Various surfaces reflect light in dift'erent degrees. Thus a
window pane, even many miles away, will reflect the sun in
dazzling brilliancy, and the sun shining on snow causes so great
a glare as to necessitate the wearing of dark goggles.

li. Cliristoplur. — D.\rk St.\ks. — You suggest that such bodies
" belong, of course, to our solar system." We believe that
no such assertion has been made by astronomers. The dark
stars referred to are supposed to exist in space, but far beyond
the distance at which they would reflect the sun's light. In
our next issue we are hoping to insert an article by Mr. Gore,
which refers to this subject.

2=iO

KNOWLEDGE & SCIENTIFIC NEWS.

[October, 1905.

Some New Discoveries

in the

Field of Radio Activity.

IJy Ur. Alfred CIkadenwitz.

I'erhaps no field of modern physics is being- so in-
tensely investig-ated as is radio-activity, and none has
sjained such popularity, even with those who g^enerallv
are strangers to natural philosophy. The phenomena
in question, which were originally attributed only to
some exceptional class of bodies, have recently been
found to be common to any one of the bodies, either
inorganic or organic, contained on earth.

Dr. Th. Tommasina, of Geneva, Switzerland, who is
one of the pioneers in this branch of science, has lately
discovered a special kind of radio-activity which he
calls pyroradio-activil y ; this is the radio-active power
taken by a wire charged with negative electricity, as it
is heated. Such a wire will induce radio-activitv in
any substance submitted to its action, so that a means
of activating these without the help of radium is thus
forthcoming.

On continuing his researches on these lines, Dr.
Tommasina, however, soon discovered a method of
imparting radio-activitv to a substance of any descrip-
tion. In fact, on account of the peculiar electric stale
or ionisalion, as it is called, produced by X-rays in the
S'jrrounding medium, any substance placed in the latter
will become radio-active.

It is thus sufficient to have at one's disposal any suit-
able outfit for generating X-rays, to impart to any sub-
stance a fairly strong radio-activity which may last for
some days. Even living organisms are liable to be
radio-activated without suffering any trouble, as the
Rontgen rays need not strike the subject. The Ront-
gen bulb may. for instance, be located in a cabinet left
ajar, the rays being directed towards its interior, so
that the "ionisation" of the air is propagated gradu-
ally by diffusion.

This opens up a field to a possible medical applica-
tion of radio-activity, which the necessity of using
radium, or other radio-active bodies Cexerting efTects
highly prejudicial U> the skin), had so far prevented.

In fact, patients can now be activated without any
trouble to them, and even while in bed, it being suffi-
cient to place the latter on insulating supports, and to
connect the patient to the inner armature of a Levden
jar, the outer armature of which is grounded, as is the
positive terminal of the induction coil. Between the

Fift. I.

negative terminal Oif the induction coil and tile inner
armature of the Leyden jar, rapid electrical discharges
are allowed to pass. By this means a fairly strong
radio-activity can readily be produced.

Any solid body, both inert and orgjuiised (such as
fruit, gra.ss, and live animals), as well as any kind of
conductive or insulating liquids, have thus lieen made
radio-;iclive. .\ny drugs, both for internal and external
use, and any material used for bandaires, compresses,
etc., as well as any .solid or liquid food intended for a
special diet, may furthermore be radio-activated by this
method without introducing any trace of radium or a
similar radio-active body.

As regards the therapeutical properties of this radio-
activity, nf)thing definite can, so far, be stated ; any
such phenomena are, however, found to be attended I v
"ionisation," which is f:ivourable to electrolysis, and
may even give rise to it. In that c.nsc a rather wel-
come action with a view to a rapid and comple'.c
assimilation of certain medicaments, such as iron in
the cure of an.cmia, niifiht be anticipatd. Moreover,
radio-activity being apparently the cau.sc of the thera-
peutical properties of cert:iin mineral waters, these m:ty
be augmented by increasing their radio-activity on the
lines above mentioned.

In connection with the above experiments, Tom-
masina noted that, apart from the temporary radio-
activity which may be imparted to animals and plants,

October, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

251

some of them possess a sliofht permanent radio-activity
of tlieir own. This is the case of any freshly-gathered
plants and their parts, such as ffrass, fruit, fioAvers, and
leaves, while the same plants, after beintf dried, show,
at most, some slight traces of temporary radio-activity.
In order tO' ascertain whether animals also have
such a permanent radio-activity of their own, Tom-
masina constructed a muff-shaped cag;e of wire g-rating,
forming- two' concentrical cylinders between which an
annular space of some centimetres was left free
(Fig-, i). The two cylindiica! wire gyrates were closed
both at the top and below by metal discs perforated in
the centre to allow of the caape being- slipped readily
()\er the insulated metal cylinder of the Elster and
Gcitel apparatus, serving to measure the radio-activity.
On the blackened cylinder of this electroscopic outfit
takes place the dispersion of electricity due tO' the
radiation from the animals put in the cag-c ; as the
latter has the shape of a narrow circular corridor, the

CORRESPONDENCE.

Pig- 3-

animal is allowed to> move freely while remaining
always at practically the same distance from the elec-
trified dispersing cylinder (see Fig'. 3). The cage con-
taining the animal experimented on is next placed in
the interior of the great cylindrical metal cylinder seen
on the left of Fig. 2 ; this is blackened both within and
without, so as to eliminate any dispersive action of
ultra-violet rays.

Though these highly interesting experiments on the
radio-activity of birds had tO' be discontinued tem-
porarily. Dr. Tommasina was able tO' state that the
phenomenon is quite general in character. The most
interesting result is, however, that the intensity of the
radio-active radiation is stronger with grown indi-
viduals than in young ones, and depends also^ on the
state of activity or rest of the subject. In fact, radio-
activity seems to he -proportional to muscular activity or
vital energy.

This phenomenon, that could be called bioradw-
activity, has doubtless a rather intimate relation with
life, and from this point of view its further investiga-
tion will probably give results of a great bearing both
on philosophical and practical problems.

The Equa-tiorv of Time iheory.

To THE EurroRs of " Knowludgk & Illustkatkd
Scientific News."
Sirs, — In your number for August, a question is put to
me by your reviewer in his observation upon the first part
of my woiU, " Some Elements of the Universe Hitherto Unex-
plained." I am sure you will permit me to reply, the more
especially as the question of your reviewer raises an interest-
ing issue upon the subject. The question has relation to
Chapter IV., which asserts that the existing theories do not
account for the cause of the sun's irregularity in time, and fur-
nishing a new explanation. The question of your reviewer is
— " How would he deal with an obliquity of 90° ? " — meaning,
I suppose, if the obliquity of the ecliptic were go°, instead of
as at present 23° 27' 5"'g2. To answer this it is necessary to
use the reputed effect of the present obliquity as the basis for
gauging the effect at yo°. To limit my reply as much as
possible, I will confine my remarks to the 30° immediately fol-
lowing the March equinox. The advantage of taking these 30^
is that the theoretical causes of the sun's irregularity are here
all acting in the same direction, if they act at all ; and the sun
is at its average distance, the actual mean occurring on
April I. If a celestial globe be referred to, it will be seen that
the distance along the ecliptic from the equinox to meridian 30
is just over ^2 degrees of arc, or 2° more than along the
equator. If the obliquity were increased to an angle of 45', it
will be found that S° is added before the 30th meridian is
reached. At an angle of 70° the e.xtra distance is 27°; at 80'^
it is 41°; at 85° it is 50°; and at go°, to make up the full
arc of go°, it is evident that 60° is required. Traced in
this way, it is seen that if the present obliquity has an effect,
the increase would continue up to go° ; it would then decrease
in the same ratio. What then would be the result of moving
the ecliptic the extreme limit of go° from the equator, or at
right angles to the equator ? At the equinoxes the axis of the
earth would be parallel to the equator. Still there would be
12 hours day and 12 hours night, just as now. But at the
December solstice the south pole of the earth would point to
the sun, and at the June solstice, the north pole on June 21,
the sun would be almost stationary in the mid-heavens. But it
would begin a small spiral, and by noon next day would cross
the iSoth meridian about one degree from the north pole.
The following day it would apparently describe a slightly
larger spiral, and continue to increase the spiral day by day,
and also to cross the iSoth meridian with an advance at the
same rate that it now moves along the ecliptic. As the
obliquity of go° results in this small circle in the sky
at the solstice (during which the sun will pass over less
than 6° of arc), will it occupy a less period of time
than the circle twice the size next day, or any of the
increased circles up to the time of the sun reaching the
equator and passing round the whole 360^ — or more than 60
times the arc distance of the small circle. It is evident
that all will occupy the same time, because the sun does not
move, but the appearance of its movement is due to the revo-
lution of the earth, and no variation can be detected in that.
It is thus seen what a valuable argument the question of your
reviewer supplies against the existing theories, because the
placing of the ecliptic at right angles to the equator not only
shows that at the greatest possible angle no difference is made
in the causes said to produce the sun's irregularity; but by
removing the effect of the earth's revolution in its orbit from
the effect of its revolution on its a.xis, it is made plain that
although the sun would appear to move from the south pole
to the north pole in the course of six months (or nearly nine
times its present change of altitude), yet it would not entail
any difference in time because it must be performed in the
period of the earth's revolution on its axis. The irregularity
in the sun's motion, due to causes which I explain in my work,
would not be ah'ected by the change of obliquity, and would be
indicated by a variation in its latitude. If the Ca;3ar of obli-
quity be appealed to, let the decision be according to what is
claimed. In the period the sun ought to move from the
equinox to meridian 30 ; if its motion be measured along the
line of the ecliptic, it must be more than 2° behind time. Two
degrees means nearly two days, or 1 hour 36 minutes per day.

KNOWLEDGE .S: SCIEXTIEIC NEWS.

[October, 1905.

That is, the amount of obliquity causes the sun to be slow, or it
has no effect. Can anyone explain away these two days if they
exist or show that any cause is operating to reduce them ? I
would like to touch upon'otherpoints, but fear I have exceeded
allowable limits.
August 17, 1905. A. Balding.

By the courtesy of the Editor I have seen Mr. Balding's
letter, and I at once admit that my supposed challenge was a
little hasty, since an obliquity of no' is a sort of paradox, and
its effect would be less obvious than that of an obliquity of
marly 90'. .Apparently, however. Mr. Balding fully realises
the sort of effect to be expected. The appeal to Ck-sar may
stand, and we may admit the approximate accuracy of the 2-.
But two degrees will not mean two days, as >tr. Balding
imagines, since, as he himself allows, the motion is not that of
the sun but of the earth, so 2'- means about S minutes of time,
or 16 seconds (roughly) per day. A very different matter to
his I hour 36 minutes. — The Reviewer.]

Eoliths-

TO THE EDITORS OF " KNOWLEDGE & ILLISTRATED
SCIENTIFIC NEWS."

Sirs, — A recent experiment in France is reported whereby
so-called Eoliths were produced by mechanical means ; the
impression caused by the report is likely to lead to some dis-
cussion on the nature of Eoliths. It appears that certain
French authorities visited a cement factory at Mantes for the
purpose of examining certain stones chipped during some
mechanical process whereby flints are separated from the
chalk matrix. At the conclusion of the process they were
astonished to find '• that the great majority presented examples
of all the Eolithic forms." On this point of similarity it is
necessary to suspend opinion, but the observers have, as a
result, abandoned all conviction that Eoliths had an .artificial
origin. No one doubts that stones somewhat resembling
Eoliths can be produced by natural processes — the Mantes
process it should be borne in mind is not a natural one— but
at the same time there is a distinction to be drawn between
them and true Eoliths. Again, with all respect to Continental
observers, it may be said that much of what is there accepted
as of human origin would here be rejected as too indefinite.
In what w;iy it can be shown that the Mantes mechanical
process resembles the action of the rivers in depositing the
plateau or any other gravels is difficult to understand. We
are told that the flints and the containing chalk blocks are
placed in a receiver full of water, and then rotated to effect
separation; but here is no parallel ot action, as in the
separating process the materials are strictly confined within
the receiver. We are further informed that the majority of
flints thus separated show work of seeming Eolithic type. In
this feature the plateau gravel compares unfavourably with
the Mantes process, for in the former the worked stones form
but a small proportion of the whole. It should be remarked
that unrolled Eoliths often occur with rolled flints, and that the
clayey nature of some plateau gravels preclude the- necessity
of supposing a violent type of deposition ; in fact, the presence
of this clay serves to show that in some cases deposition went
on in a tranquil manner, or under circumstances not favourable
to the abrasion of flints. How, it may be asked, can the
presence of unrolUd Eoliths in this clayey drift be explained
away other than by suggesting that they were dropped near
these ancient streams and subsequently covered by the con-
taining clay ?

I'nder any circumstances the Mantes pseudo- Eoliths do not
dispose of the evolutionary contention for a period when man
had not arrived at the Palitolithic stage of his culture.
Professor Boule and Dr. Obermaier will shortly discuss these
psendo- Eoliths, when they will doubtless give reasons for the
contention that a modern mechanical process can be admitted
as evidence against fh<> h-imnn origin of Eoliths.

That natural a-; ' ure flints is admitted, but the

n.-iture of the tract said to bear with it its own

explanation; anot:. ,n is demanded by the definite

types of Eolithic iriit.;. :i:miI,. For this re.-ison, then, all
students of these early forms will await with interest the
advent of these pseudo Eoliths from the Mantes cement yards

Chelsfield, Kent, Yours faithfully,

August 17, 1905. J. KISSELL Lahkhv.

Photography.

Pure and Applied.

By CH.iP.MAN Jones, F.I.C, F.C.S., &c.

Scnsiiiicrs. — The action of certain dyes and .•similar
organic substances as sensitisers for photofjraphic
plates, ospcciaJly for conferring' increased sensitiveness
to green and red light, is so well known that it is
interesting to note the effect of similar bodies wheji
added to other light-sensitive substances. Messrs. M.
Calmels and L. P. Clerc (I.e Men. de la Phot., July ;
.Abstract, Jul. Royal Phot. Sac, .August) have experi-
mented in this direction with bichromated gelatine and
albumen, as used in photo-mechanical work (making
process blocks). One sample of erythrosin doubled the
sensitiveness of a gelatine film, another increased it to
three times, while a sample of eosin made it four times
as sensitive as when untreated. From two to four
grams of the colouring matter to cacli litre of the pre-
pared bichromaled solution of gehitinc or alluiiiKn is
about the maximum c|uantity, and when more than this
is added the scnsitivenc.ss of the resulting film is de-
creased. Messrs. A. Jodlbauer and H. V. Tappciner
{Ber. p. 2602 ; .Abstrr-ct, Jul. Sac. Client. Iiid., p. 903)
find that the sensitiveness to light of a solution of
mercuric chloride and ammonium oxalate (;ui used in
photometry) is increased by the addition to it of cer-
tain fluorescent substances, including fluorescein and
its chlorine, bromine, and iodine derivatives. It would
be interesting to know the character of the added sen-
sitiveness in these cases, whether the substances used
are "colour sensitisers," as the expression is used in
relation to gelatine and colltxlion plates. But, in any
case, until it is shown to be otherwise, a broad dis-
tinction must be made between the effects just referred
to and the sensitising of silver s;dts, because, in tlic one
case, it is a definite chemical change that is quickenod,
while in the other the change is presumably not chemi-
cal at all, though, further than tJiis, nothing is known
of its real nature.

llie Principles of l)evclo[>mc>it, etc. — 'Hie recent com-
munications of Messrs. Sheppard and Mees deal with
matters that have an important be:iring upon photo-
graphic procedure, and from them I have gathered the
following results and conclusions. It must not be sup-
posed that these results can be applied without modi-
fication to all circumstances that appear to be similai
to those staled, as investigators c.innot be held re-
sponsible for the moclifications that plate-makers maj
see fit to introduce into their forniulie, or photographers
into their methods. The plates used were, I believe,
.•-peciailv prepared by coating iil.ile gl.iss with a simple
emulsion containing less than one per cent, of silver
iodide, and the minimum of soluble salts.

The quantity of silver that is found in 100 square
centimetres of film after exposure and develo[)ment to
give a "density" (opacity logarithm) of unity, the
authors find to be .01031 gram as a mean of several
experiments. luler had previously obtained the same
figure, but Hurler and Driffield found .0121, and sub-
se(|uently, .0131 gram. 'Ihe authors suggest that this
discrepancy is due either to a constant error in llurtcr
and IJrilHeld's photometer, or else to the plates used.
I believe th-it it is a common experience with plate-
makers that very much more silver is necessary to
giw* density in a quick plate than in a slow one From
this, and other considerations, I should have expected

October, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

253

lliis figure to vary considerably, accordiiiij to the char-
acter of the plate.

The discrepancies obtained in the results of measur-
ing plates similarly exposed and developed gave ir
three series of experiments 3.2, 2.2, and 6.0 per ceni.
as the greatest deviations from the mean density m
each case. These errors, due to the plates, were ob-
tained by the use of an emulsion specially coated on to
plate glass, but not by means of the apparatus the
authors have sinci constructed for coating experi-
mental plates.

Concerning the velocity of development with ferrous
oxalate, the authors find 'that _(t_) the silver is deposited
at first with increasing rapidity, then more slowly,
tending to a limit that depends only on the exposure,
(2) the velocity is proportional to the concentration of
the developer, but that this relationship is liable tO' be
interfered with by the accumulation of the products of
the reaction in the film, (3) a soluble bromide reduces
the velocity, but the reduction becomes less as the
action proceeds, (4) as the bromide is increased in geo-
metrical proportion the velocity diminishes in arithmeti-
cal proportion, (5) hardening the film is without effect
on the velocity of either developing or fixing, even when
a four per cent, solution of formaldehyde was applied
until the film was insoluble in cold water, (6) the velo-
city of development varies with different plates, and
diminishes for a given plate as it gets older, (7) the
velocity depends mainly on the rate of diffusion of the
developer.

Concerning the grains of silver and their disposition
in the film, the authors find that (i) by short develop-
ment the depth to which the image extends is inde-
pendent of the exposure (I suppose in the absence of
soluble bromides), but that finally it becomes a maxi-
mum for each exposure ; (2) by exposing through the
glass, still the grains most exposed begin to develop
first ; (3) the size of the grains increases during deve-
lopment until finally it is independent of the exposure ;
(■4) the addition of bromide causes a diminution in the
size of the grains.

Many of these conclusions are in full agreement with
the everyday observatio'ns of photographers, and the
results of previous investigators. It will, however,
doubtless surprise many to learn that the velocity of
development and fixing is not affected by the harden-
ing of the film.

Mr. Sheppard has also published in the Journal of
the Chemical Society for August a communication on
development as a reversible reaction, and on the re-
tarding action of soluble bromides. I have refrained
from referring to anything stated therein, because, as
the author says that it bears on many points in photo-
graphic practice, he will, doubtless, shortly indicate its
practical importance himself. But I would remark on
the fact that in using the word "reversible," he does
not appear to consider the difference between develop
able and non-developable silver bromide. The silver
bromide is reduced by the developer, because it is in the
developable condition, undevelopable silver bromide not
being reducible under the same conditions. When the
reaction is reversed, the resulting silver bromide would,
I suppose, not be likely to be in the developable state.

The Royal Photographic Society.

The annual exhibition of pliotoRrapIis was opened on tlie 20th of
September at the New Gallery Kegent Street, and will remain open
until October 2Sth. The large collection will be found of considerable
interest to photographers. Amongst other items of scientific
interest are some fine specimens of X-ray work, and some examples
of three-colour printing.

ASTRONOMICAL.

By Charles P. Butler, A.R.C.Sc. (Lond.), F.R.P.S.
Nova. Aquilae. No. 2-

In a telegram circulated from the Kiel CentralstcUe, Pro-
fessor Pickering announced tiiat Mrs. Fleming had discovered a
new star from examination of plates obtained at the Harvard
College Observatory. The star was situated near X Aquilae,
and was stated to be fading rapidly at the time of discovery,
September i.
The position first circulated was

R.A. = 284° 2' = i8h se-i-".
Decl. = - 4° 34' ;
but a later wire gave a more accurate value of the right ascen-
sion as R.A. = i8h 57m 8s.

Hy September 4 several visu.al observations had been made.
Professor Max Wolf reported that at Heidelberg the star was
observed on September 4, the magnitude being then about (y^.
The position was determined to be : —
R.A. = 18^5411245 ) (Epoch 1855).
^ , 1, „ I 1905, Sept., 4'* 9*1 30"! Koenigstuhl

Decl. = - 4" 39- J ii'ean Time.

On September 6. Dr. P. Guthnick telephoned that he had
been able to observe the new star at the Bothkamp Observa-
tory, and giving its position to be : —

18 54 25
iS 57 4

4 3S-8
4 348

1855-0
19050

The magnitude on September 5 was about 10-2, and the
colour greenish yellow.

Beginning of the New North Polar Cap
of Mars.

An interesting observation was made at the Lowell Observa-
tory, Flagstaff, Arizona, on May ig, 1905, 'which determined
the' important fact of the definite time of formation of the
new north polar cap of the planet Mars. A large white patch
was first noticed south and west of the old polar cap, and it
was quite certain that nothing of the kind was visible the
day before. The season would correspond to that about
August 20 with us. In extent the area of the new patch was
enormous. On the 20th the white patch was again visible
and showed a brilliant kernel at its southern end in longitude

+ 70".

The date of this formation was 126 days after the summer
solstice of the Martian Northern Hemisphere, and it is very
important to note the agreement of this value with that
first determined in 1903, which was given at 128 or 129 days
after the northern solstice, as this shows evidence of constancy
of meteorological cycles on the planetary surface.

Further Observatiorvs of Jupiter's
Seventh Satellite.

From a telegram circulated by the Kiel Centralstelle, we
learn that Professor Albrecht has obtained another determi-
nation of the seventh satellite of Jupiter, with the Crossley
Rellector of the Lick Observatory, as follows : —

Position Angle. Distance.
1905, Aug. 796 G.M.T. .. 2S9°-7 .. 54' 6

In the Lick Observatory Bulletin. No. 82, a set of elements
for the satellite are given by F. E. Ross, computed from the
observations by I'errine, on January 3. February 8, and
March 6, 1905.

'■54

KNOWLEDGE c^- SCIENTIFIC NEWS.

[October, 1905.

Ecliptic Elements.

Mean Jovicentric Longitude at Epoch
Longitude of Perijove
Longitude of Node
Inclination to Ecliptic
Inclination to Jupiter's Orbit
Longitude of Node on Jupiter's Orbit

333 55 \
llt%\ 1905.

3'° G.M.T.
320

2386

Elements referred to Earth's Equator.

Mean Jovicentric Right Ascension
Right .Ascension of Perijove..
Right Ascension of Node
Inclination to Equator

Mean daily motion

Log. a

32818 1905.
33 1 "28 -Jan. o-o
281-13 1 G.M.T.
262 I

= i°-358
= 8-9004
a = 52''54

e = 00246

Period = 265-0 days.

Distance at maximum elongation — 70'.
It is thought that the combined observations of the sixth and
seventh satellites will furnish material for a new determination of
the mass of Jupiter, which should be comparable in accuracy with
the best results hitherto obtained.

Ephemeris for Observations of Jcpiter's Seventh Satellite
Greenwich Mean Noon. Position Angle. Distance.

1905 October 4

290

289

288

287

November 3

285

284

2S3

.^^^^^^

CHEMICAL.

By C. AiNswoRTH Mitchell, B.A. (O.xon.), F.I.C.
Commercial Phosphorus Sulphide.

Thk teriible effects, uotably the decay of the jaw bone, pro-
duced by the ordinary white phosphorus upon the work-
people in the match factories have led to many attempts
being made to find a satisfactory substitute. The red modifi-
cation of phosphorus is non-poisonous, and does not produce
the physiological effects of white phosphorus, but has the
drawback of not being ignited by friction, while the scarlet
modification discovered by Dr. Schenck has not yet come into
general 'i:,' . .ilthough it appears to be non-poisonous and yet
cheriii In the national match factories in I-Vance

a sill; :)horus has been used for several years for

the tip that will strike anywhere; and it is stated

that the di.-.ea3e is now unknown there. It is most essential,
however, that the sulphide should be quite free from white
phosphorus, and M. Leo Vignon has therefore made experi-
ments as to the best means of detecting it. He finds that the
commercial product usually consists almost entirely of
phosphorus sulphide, I'lS., and contains about i per cent, of
free pho.^iphorus which is of the red modification, and there-
fore harnil'-c:. Th" only test that gives satisfactory results is
to p.i . "• • ■ :,j^en ovf-r the product, when in the

pre,-,' rus the gas bcctimes phosphorescent

in th' with a green tlarne, yielding phos-

phoric !■ ) i. Ail :, I iti ii': identified by well-known tests.

An Anti-Serum for Hsxy Fever.

The hay fever of Murops is, as is well known, caused by the
pollen of a large number '>t plants— notably grasses; while the
widesprrnci and mnrr cr-rinii- '- nut'imm! rold " of North
Amcr: , ■ rag weed

(Anil nllicniiims.

The " ted by Pro-

fessor I.ii.i.ljar, of th'j lly„-i>_ii;'- Iii..t:t ;te ol 1 huiibiirg, and a
simple method of serum treatment dcvis'd. A substance of
an albuminous character could bf i.'iolated from each of the
active pollens by extraction and precipitation with alcohol and
salt, and this substance produced all the symptoms of hay

fever in susceptible individuals. I'nlike the true toxines pro-
duced by many pathogenic bacteria, it was not destroyed by
heat, and could also resist the action of dilute acids and of the
ferments of the digestion, though it was sensitive to the action
of alkalies. Different individuals varied as regards their sus-
ceptibility to its action ; but as a rule a dose of , oVs 'o .-o'sii of
a milligramme was sufficient to produce all the local toxic
effects. An anti-serum was obtained by inoculating rabbits
with this preparation, and the immunised serum thus prepared
neutralised the poison outside the body, and in practice pro-
tected susceptible subjects against the pollen. It is now sold
as a commercial preparation under the name of poUnnfin,
either in the liquid state or in the form of a powder, obtained
by evaporating the serum in a vacuum. It is only intended
for external application, for although subcutaneous injection
does afford some protection, the immunity is only partial, and
does not last more than a few d.iys at rr.ost.

The Composition of Soot.

Mr. E. Knecht has examined numerous specimens of soot
of various origin, and especially that from the Manchester
chimneys. This was found to contain about 11 per cent, of
ammonium sulphate, 20 per cent, of other mineral matter
(ash), and ij per cent, of substances soluble in benzene, the
residue {46 per cent.) being assumed to be carbon. The sub-
stances soluble in benzene were hydrocarbons of high boiling
point, while the insoluble residue was a brownish highly in-
flammable powder, taking fire spontaneously when heated to
the temperature of boiling water. l-"xtraction of the soot with
alkali yielded a brown product, from which a dyestuff could be
prepared, giving fast shades on cotton, ranging from fawn to
dark brown. London soot contained a very much smaller
amount (1-3 per cent.) of substances soluble in benzene, while
soot from Prague (lignite coal) yielded only 0-2 per cent, of
these substances and contained only traces of ammonia.

GEOLOGICAL.

By Ki.uAKD A. Maktin, F.G.S.

Niagara's Horse-pou'er.

According to a recent survey of I'nited States engineers,
the Niagara Kiver in its course from Lake Erie to Lake
Ontario falls a distance of 327 feet, and discharges 230,000
cubic feet of water per second from one lake to the other. At
the same time it develops an equivalent of about 9 million
theoretical horse-power, of which 50 per cent, is estimated to
be available for industrial purposes.

Glaciation of Turkestan.

Evidence of the extension of what we know as the Glacial
Period accumulates. Mr. Ellsworth Huntingdon, in " Explora-
tions in Turkestan " (Washington), claims for the neighbour-
hood of his explorations as many as six advances and six
interglacial withdrawals of the ice, basing his claim on the
phenomena exhibited by those valleys which still contain
glaciers in them. The idea that the Glacial Period was con-
fined to any one portion of the globe is vanishing before the
advance of geological science, and Croll's so-called astro-
nomical theory no longer gives an acceptable explanation of
the phenomena of the age.

Black Gault.

In the process of c.vcavaliiig lor drainage in the village of
Ditchling, in Sussex, three pits have been dug to a consider-
able depth, each pit being separated from the next by about
200 yards. At a depth of 10 feet, black carbonaceous clay has
been reached, so thickly impregnated with black vegetable
matter as to constitute a soft lignite. The base has not been
reached, but it extends to at least a thickness of 15 feet. The
village is situated about a mile north of the chalk escarpment,
and the outcrop of the gault clay is midway between the hills
and the village. The black mud is covered with what is pro-
bably the wash of the lower grcensand beds of the higher
ground somewhat farther to the north, and no doubt represents
a basemcnt-bcd of the gault cl.iy. It promises to yield a large
quantity of water, should it at any time be necessary to utilise
it for the purpose.

October, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

255

White Tertiary Limestone at Heme Hill.

In my collection are some pieces of hard white limestone
which I collected some time ago in what is now the end of
Rosendale Road, Heme Hill, when excavations were being
made for house-foundations. Tertiary limestones are, of
course, not unknown in our country, the Isle of Wight Oligo-
cene beds being instances. I do not remember, however,
having seen any reference to Eocene limestone in the neigh-
bourhood in question, and the point seems to be worthy of
record. Some of the rock was so hard as to have necessitated
the use of the pick and crowbar in its excavation, and
resembled the " Chalk Rock." Some portions were to some
extent siliceous, whilst others bore a close resemblance to
ordinary chalk. The stratum was fairly extensive, and. so far
as one can judge from the work of the Geological Surveyors,
it probably forms a stratum of the Woolwich and Reading
series.

Mammals in the Wandle Valley.

Amongst the Mitcham gravels the following Pleistocene re-
mains have been found, and are to be seen in the Croydon
TowQ Hall: Tooth of Mammoth Calf (E/cpIuis priinigeniiis) ;
tusk of ditto ; bones of Bos primigcjtii/s ; bones of horse (Eqiius
cahalliis). In the Thornton Heath gravels have been found
five teeth and numerous fragments of bones of Elephas priini-
i;i-nius. These are preserved in the Grange Wood Museum,
together with 5 feet of a tusk from the Mitcham gravels.

ORNITHOLOGICAL.

By W. P. PvcRAFT, A.L.S., F.Z.S., M.B.O.U., &c.
Bird Outlaws in Norway.

Birds of prey in Norway are apparently kept under with a
sternhand. Thei'"/V/i of August 26containsalist of carnivorous
mammals and birds upon whose heads a price is set by the
Government. Last year head-money was paid for 108 eagles,
130 eagle owls, 93 gyr-falcons and peregrines, 437 goshawks,
8S0 sparrow-hawks, and 1034 divers. We cannot congratulate
the Norwegians on the war of speedy extermination which
they are prosecuting.

Montagu's Harrier in Northumberland.

Mr. Abel Chapman, in the Field of September 2, writes to
protest against the " brutal and selfish " destruction of a
Montagu's Harrier (Circus cineraccus) on the Moors of Coquet-
dale, Northumberland, in August last. This bird, a female,
had apparently haunted these moors for some weeks only to
be shot at last by a game'.ieeper. Mr. Chapman writes with
some warmth on the matter, and we most heartily endorse
his remarks.

Hen Hatrrier in Norfolk.

A male and female hen harrier (Ciyciis cyancits) were shot
(Field, September 9) " during the last few months — the one at
Snettisham, the other at Wolferton — while quartering the
marshes." Both were immature birds.

White Stork in Norfolk.

The Field of September 9 records tlie occurrence of a white
stork (Ciconid alba) at North Wotton. Of course the bird was
shot, and proved to be an adult male in full plumage.

Great Snipe in Shropshire.

An immature specimen of this species is recorded by Mr.
E. G. Potter in the F(.7>/ of September g as having been shot
at Frees, near Whitchurch, Silop. The sex of the bird is
not stated, but the weight was 6 J o^s.

Dusky Redshank in Kent.

The Zooloi^ist for September records the shooting of a pair
of Dusky Redshanks (rof(7i(;(,s fusciis) at Jury's Gapp, Lydd, on
May 2g, both birds being in summer plumai^e.

Squacco Heron in Kent.

A specimen, fully adult (sex not stated), was shot in a grass
field at Rye, Sussex, according to the Zoologist for September,
on June 3. This makes the forty-first authenticated occurrence
of the species in Great Britain.

PHYSICAL.

By Alfred W. Porter, B.Sc.

An Electrical Experiment.

Professor Worthington, of the Royal Naval Engineering
College, Devonport, has recently tested whether any differ-
ence can be detected between space which is at a high electric
potential and space at a low potential quite irrespective of
the existence of any electric field in the space in question.
In explanation of this last proviso we nnay remind the reader
that electric force arises whenever there is a difference of
potential between two points; so that the absence of electric
force implies that the experiment must be so performed that
the electric potential has a uniform value. Use is ^made of
the fact that the potential inside a closed conductor is uniform.
Two such conductors, consisting of long tubes of semi-circular
section, were placed with their flat sides separated by a sheet
of ebonite only. These tubes were connected to the knobs of
a Wimshurst machine, and when the machine was excited the
space inside one of them would take a high positive potential
— practically uniform throughout it — whereas the other space
would have a much lower (or negative) uniform potential.
The experiment consisted in looking for a possible effect of the
potential upon the velocity of light. An ordinary interference
device was employed, i.e., light from a single source was split
into two beams, one of which passed down one tube, the
second down the other. These beams were then brought to-
gether again by a telescope lens, and in the overlapping region
interference bands are observed. If the effect of the high
potential is to increase the velocity of light then these bands
will shift. " When care was taken not to touch either table,
no shift whatever could be detected either when the spark
occurred or while the potential difference was accumulating."
The spark referred to was at the adjustable knobs of the
machine, which were kept i\ inches apart. This distance
determined the maximum difference of potential, viz., 60,000
volts; the length of the tubes was 152 cms. Assuming that
a shift equal to one-twentieth of a band could have been
detected if it had occurred, it follows from its absence that if
there is a difference of velocity it is less than sV^d of one-
millionth of the velocity itself.

Ether-drift.

Prof. Brace has recently extended the tests on a possible
influence of ether-drift on rotary polarisation using oil of
carraway seed instead of quartz, and concludes that the
effect of the motion of the earth on the rotation in active
substances is certainly less than one part in five million,
and probably less than one part in ten million of the total
rotation.

The Future of Science.

In an interesting article in the July number of the " Popular
Science Monthly," Professor Dolbear asks, " Is there no
more work for the man of science ? Are there no more
problems of importance awaiting the investigator ? Have we
all the knowledge we are likely to get ? There are some who,
having noted the prodigious product of the nineteenth cen-
tury, have half feared that science has been worked out."
We would point out that a glance at almost any scientific
journal should act as a tonic to any one who may be taking a
depressed view of the situation. It is not a distant retro-
spect that we must make in order to reach a period of scien-
tific prosperity. There probably never was a time in which
greater advances were being made than the present. Pro-
fessor Dolbear, however, is not himself a pessimist. He
asks the question merely as a preface to some suggestions of
his own as to future lines of research. We select one para-
graph only: "When the ether is understood we shall be able
to understand, in a mechanical sense, how moving a magnet
disturbs every other magnet wherever it may be ; why
chemical compounds are possible ; why crystals assume geo-
metrical forms ; and why cellular structure in plants and
animals can embody what we call life."

2^6

KNOWLEDGE & SCIENTIFIC NEWS.

[October, 1905.

ZOOLOGICAL.

By R. Lydekker.
The Pen-Tailed Tree-Shrew.

Borneo has hitherto been supposeJ to lo the sole habitat
of a very remarkable little animal known as the pen-tailed
tree-shrew 1 Ptiloccrcm louei). The creature is a near ally of
the tupais, or tree-shrews, of the Indo-Milayan region, but is
\ en.- small, and has an exceedingly long cylindrical tail, which,
instead of having a fringe of long hairs on opposite sides
throughout its length, is furnished merely with a vane of such
hairs near the tip. Recently a specimen has been taken in
the Selangor district of the Malay Peninsula. Since the long-
uosed crocodile known as Sihlegel's gharial (Tomistoma
schlei;eli), which was also long supposed to be confined to
Borneo, has likewise been discovered in the Malay Peninsula,
it is evident that the fauna of these two areas has more in
common than was formerly supposed.

A Giant Pig.

From the later Tertiary deposits of Nebraska has been
recently described the fossilized remains of a gigantic fossil
pig. which has been named Diinuhuriis lioll.indi, in honour of
the Director of the Carnegie Museum, who recently brought
the Diploilocus skeleton to the British Museum. Some idea
of the enormous size of this monster will be gathered from the
fact that Its skull alone measures nearly a yard in length.

The "Siruk\i."

The Mandingos of Liberia, according to Sir H. H.Johnston,
" talk a great deal about a striped animal which they call
siruku. They recognised a picture of a zebra, and called it
siruku, but at the same time described the animal as being
extremely ferocious and dangerous to life. As it is impossible
to recognise this description as applying to the zebra, I
thought from their gestures that they mit^ht mean the leopard;
but to the leopard they gave a totally different name — soli.
Moreover, they were particular that this animal had stripes.
It may be the striped hyxna. .'It the same time, on every
occasion when they were shown the pictures of a zebra they
declared that this was the creature they called siruku, but that
in their countrj- it was ferocious." Even if the siruku be the
striped hyxna, it will indicate an animal — possibly a distinct
race or species — new to the West African fauna. In India,
at any rate, striped hyaenas are skulking cowardly brutes,
which never voluntarily attack man ; but this scarcely accords
with the character given to the mysterious Liberian animal.

A Gorilla at the " Zoo."

The menagfirie in the Regent's Park has received a fine
female gorilla, imported from French Congo-land, in company
with no less than seventeen young chimpanzees. On arrival
at the docks, the gorilla was reported to be in fair health,
although sufl'ering from its somewhat restricted quarters on
board ship, and since its transference to the Regent's Park has
apparently done well. It is the largest specimen imported of
late years.

Bubble-Nesting Fishes.

Most, if not all. of the fishes allied to the celebrated
"climbiog-perch " (.liui'im \caiuicii'.) have the remarkable
habit of constructing "nests" or floats of bubbles, in which
Ihcir eggs are placed during the period of development. All
these fishes arc brilliantly coloured, and, with the exception of
one African species, are natives of the Indo-Malayan rivers.
Among those definitely known to make floats of this nature
arc the gourami (O-phmmniu^ aljux), renowned for the ex-
cellence of its flesh, th<' paradise-fish tPolyacniilhiis opcrcularis),
and the fighting-fish (Hilla f'li^iuij-], so-called on account of a
domesticated breed being kept for fig'nting by the Siamese.
Specimens of the two latter have recently been kept in
aquariums by an Knglish naturalist, where they have con-
structed their bubble-rafts, which arc more or less dome-like
in shape. In the case of the paradise- fish, the layers of bubbles,
which are blown by the male fish, are gradu.illy increased, and
to such an extent that the eggs are raised above the level of
the water, in which position they are batched.

REVIEWS OF BOOKS.

Spectroscopy. E.C. C. Baly, F.I. C. (Longmans; los.Od.^. —
There is probably no subject for which a new English text-
book was more required than that of spectroscopy. The
advances made have been so considerable that a mere revision
of any existing textbook would have been totally insufficient.
In Germany a thoroughly satisfactory encyclopa;dic hand-
book is being brought out" by Professor Kayser, and this will
probably serve as the ultimate book of reference for some
time to' come. But this is too elaborate a treatise for the
ordinary- student, even when the language in which it is
written does not prove an obstacle. The repro.ach that there
is no adequate English textbook is roniovcd by the present
publication, which forms one of the textbooks of physical
science edited by Sir William Ramsay, who is to be congratu-
lated on having placed the subject in the hands of one so com-
petent to treat it with distinction. The characteristic feature
in the treatment is the fulness in the descriptions of experi-
mental detail, and of the conditions upon which success in
spectroscopic measurements depends. Tho prismatic and
difl'raction spectra, and the much derided but now victorious
interference methods for the determination of wave-lengths
are successively described in great detail. It is a pity that the
present edition was not in time to make use of Schuster's
recent important demonstration of the erroneoiisness of much
that has been written and accepted as gospel on the purity of
spectra. The survival of this error vitiates part of what has
been written in Chapter .\. The student may here be warned
that Schuster's original expression for the purity (p. 317) must
be accepted in place of the more elaborate (but erroneous)
formula of Wadsworth's ; and consequently he should alter
the formulye in this chapter accordingly.

Sixty pages are devoted to the means of producing the
luminous sources of spectra ; and twenty-four to the various
kinds producible. Chapter XV. consists of an elaborate and
very complete account of the series of lines in spectra and
the different formula; which have been devised to represent
them. We miss, though, any reference to N.agaoka's theoretic
discussion of the reason of the existence of these series.
There is a wide field here in which much has yet to be done;
and the full and clear account which Mr. Baly gives will be a
very welcome summary of experimental facts to those who
are interested in the matter. An outline of present experi-
mental knowledge of the Zeeman effect forms Chapter XW.
It must be understood that the treatment throughout is limited
to simple mathematics. It is, of course, impossible to put
everything under one roof; and copious references to original
sources guide the reader who wishes for fuller information.
There are very few inaccuracies. The first account of the
ideal grating was given by Schwerd not by Rayleigh ; and
Newton ilid use a slit ; though it is quite common to find it
denied of him. In biaxal crystals iieillier ray is, in general,
ordinary; the definition of optic axis on p. 96 is imperfect.
The logic on p. 155 in connection with resolving power is of
the circular type. These, however, are minor matters ; and
they do not appreciably detract from the great value of this
important work.

Structural and Field Geology, by James f jcikic, LL.D., &c.,
author of " The Great Ice Age," &c. (I'^dinburgh : Oliver and
Boyd. London : Giirney and Jackson. I'p. xx. and 435.
Price I2S. 6d. net. With Oi full-page plates, and 142 illustra-
trations in the text). — It is a pleasure to call attention to this
excellent mantial, in which Dr. Gcikie has traversed the whole
field of the geological world in a m.anner which must cause it
to be of the utmost value, both to the purely scientific geologist
and to those eng.aged in professions in which a general know-
ledge of the principles of geology is a necessity. While fur-
nishing excellent reading for the general public interested in
the subject, it will undoubtedly be useful as a manual to guide
the student in the acquisition of exact and accurate knowledge.
It is a work, loo, which should be in the hands of all engineers
who have in the slightest way work to do in which a knowledge
of the constituents of the crust of the earth is neces.sary. The
illustrations are excellent, and in the absence of actual speci-
mens of the minerals and rocks referred to in the text, nothing
could be better for purposes of the student. As ins'ances, we
may mention the section of an agate, on Plate I. ; tabular

October, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

257

granite of Goatfell, on Plate XXXV. ; columnar basalt, on
Plate XXXVII ; and dendritic markings on limestone, on
Plate XXVII. Students are carefully shown how geological
surveying is performed in Chapter XVIII. and succeeding
chapters. Dr. Geikie has produced an excellent work which
will, if possible, increase the esteem in which he is held by the
geological world.

Elementary Experimental Science. W. M. Heller and E. G.
Ingold. (Blackie and Son.) This is a book written essentially
for teachers and not for pupils. It represents an endeavour
to indicate the spirit of the teaching and the method of in-
struction to be followed in order that the maximum educational
efficiency may be obtained from the subject. With the ex-
ception of one object lesson on feathers, all the lessons are on
physics and chemistry. It would be easy to select other
experiments, and any specially intelligent teacher would no
doubt do so ; but to the more ordinary man who can value
the advantage of assistance in this respect the book must be
very highly commended. When the British Association met
at Belfast, the writer of this notice had the pleasure of being
conducted through an exhibition of pupils' work which had
been done on the same lines as those described here. The
conductor was him=elf a pupil; and it is unquestionable that
in one lad, at any rate, the methods had succeeded in creating
a lively interest in experimentation. There was, indeed, one fact
which he spontaneously stated that he could not understand ;
viz., why a small body of water in the narrower limb of a
U-tube can balance the larger body in the other limb. We
have, therefore, looked up this particular point in the book
before us, and we find that the treatment of the subject of
Huid pressure is not very clear. The method throughout is
the heuristic one — a phrase which as defined in the introduct-
tion refers to " carefully directed inquiry." But how can it be
inferred from experiment 96 that the earth is subjected to an
atmospheric pressure in every dinctioii of about 15 lbs. per
square mch. The fact implied by the three words which we
have put in italics cannot be deduced from the experiment
itself; nor can it be from any other of the experiments
described. When we have made these criticisms there is
none of an adverse nature to make. We cordially recom-
mend the book to every school teacher or to any one who
is concerned with the creation of scientific habits of thought
in children.

Bird Life Glimpses, by Edmund Selous (London: George
Allen, 1905). — This book contains a great deal of " twaddle,"
and not a little that is akin to nastiness — most decidedly it is
not a book that we should care to put into the hands of the
young. Detailed descriptions of the act of coition as practiced
among birds are not, surely, subjects which should be dis-
cussed in a book which has all the outward semblance of a
volume designed for the children's library, or the drawing-
room. Apart from this, its pages contain a great deal of
padding that could well be dispensed with. Such, for ex-
ample, as the discussions on Art and Psychology, which are
irritating. The author here and there condescends to say a
kind word for scientific men, and now and then, apparently
lest they should become puffed up by such notice, he pokes
fun at them — fun of a sort ! Occasionally he indulges in a
little hypothesis hatching — we venture to think the resulting
chicks are destined to fill an early grave. We are sorry not
to be able to speak more favourably ot the book, for, like the
curate's egg, it is good in parts, and the author writes in a
pleasing style, except that he will bespatter his pages with
phrases in French, German, and Latin. He makes even the
poor birds talk in German ! The most pleasing feature of the
volume is its illustrations, which are delightful — as pictures by
Mr. Lodge always are. W.P.P.

Poisonous Plants of all Countries, by A. Bernhard Smith
(Bristol: John Wright and Co. London: Simpkin, Marshall.
Pp. 88). — This little book consists of tables of various plants
arranged according to their action on the brain, spinal cord,
heart, together with lists of vegetable irritants. In each case
the toxic principle or principles are given. It would, perhaps,
have been interesting to the general student if remedies had
also been given. As a compilation, the work has apparently
been done well. There are two coloured plates illustrating the
fungi.

The New Science of Causation, by H. Croft Hiller (Walter
Scott Publishing Co. ; los. net).— Consisting of " Easy Duo-

logues, laying bare the hitherto hidden, and ensuring a general
collapse of the foundations of Materialistic Science." This is
but a collection of childish arguments strung together and
couched in grandiloquent phraseology, and if it be said that
it contains some few suggestions worth thinking over, that is
all that can be said in favour of this pretentious work.

Pannell's Reference Book (The Granville Press; price 6s. 6d.
net). — This volume contains a really marvellous amount of
information, and is quite the most complete reference book
we know of. The price too is extraordinarily low for a volume
of nearly 1000 pages. Large cyclopaedias are all very well for
those who have the time to study them, but for purposes'of
reference, to ascertain some fact such as one continually
wants to know, this work seems to be amply sufficient. There
is just a question as to whether the arrangement is perfect.
One will have to learn one's way about the book before the
desired information can be readily got at. It may often be
a difficulty to know whether to refer to the Dictionary, the
Dictionary of General Information, or to the Medical, Legal,
Social, or Commercial Guide to ascertain some particular
fact. Cross references might be given more freely. For in-
stance, if you look up " Bridges " in the General Information
Section, many facts are recorded, but no reference is made to
p. 420, where may be found many details of " Notable
Bridges." The information given seems to be, on the whole,
very correct, though one might naturally expect, in so com-
prehensive a collection, a few inaccuracies or omissions.
Scientific facts are concisely given, if sometimes a Httle too
vague. For instance, under the heading of " Stars " it is
stated, with reference to the grouping in constellations, " of
these, twelve are visible in both the northern and southern
hemispheres, and are known as the Zodiacal constellations ;"
and agam '• In the Southern hemisphere the chief constella
tions are Orion and the Southern Cross." Such statements,
though slightly misleading, cannot be said to be incorrect.
There is so much within these covers; what with "Hints to
Authors," "Guide to Professions," " Heraldry," " Elections,"
" Customs Tariffs," " Social Duties and .-Vids to Culture,"
Statistics, &c., that it is impossible to mention all in detail.
On the whole this book is to be thoroughly commended, and
should prove so useful and so desirable as an educator that
we should like to see it in every home and in every office
throughout the empire.

"The Zoologist," for June, July, and August.— Among the
more important articles may be mentioned one by Mr. J. G.
Millais in the June number, on the affinities of the black rat
{Mils nittus) and its relatives, in the course of which a race
new to the British Islands is described and figured. In the
July number is published the interesting address on bird
migration read before the recent Ornithological Congress by
Dr. O. Hermann, and an article on terns in Norfolk by Mr.
A. H. Patterson. Extermination in animal life forms the title
of an article in the July issue (to be followed by others) from
the pen of the editor, Mr. W. L. Distant, in which some
remarkable errors in connection with distribution are notice-
able.

The Museums Journal, Vol. IV., July, 1904, to June, 1905,
pp. X. + 245, illustrated (London : Dulau and Co., 1905 ;
price, i2s. net). — According to the report read before the
Norwich Conference in the summer of 1904, the Museums
Association continues to make steady progress, its roll of mem-
bers augmenting, its finances increasing, and its annual
volume increasing in size. Its usefulness to those connected
with museums seems also to be more and more appreciated
year by year ; while it is extremely satisfactory to learn that a
certain number of delegates now attend its annual conferences.
A very useful feature of the Journal is the list of museums in
Great Britain and Ireland, of which a portion appears in the
volume before us. Much of the success of the Association
and its journal is due to the untiring efforts of the Secretary
and Editor, Mr. E. Howarth, of Sheffield.

We have received from Messrs. S. Rentell and Co. their
catalogue of books on electricity, which includes works on all
branches of the subject, varying from 6d. to 63s.

KNOWLEDGE & SCIENTIFIC NEWS.

[October, 1905.

Conducted by F. Shillingto.n bcAi.Es, f.r.m.s.

Limit of Visibility of IsolaLted Elements
in the Micioscope.

K. Strehl has made sonic interesting ubi.ervations in
connection with the recent work ol Siedenlopl and Zsig-
mondy, whose speculations as to the visibility of ultra-
microscopic particles he reg-ards as partly hypothetical,
partly not Iree from other objections, and considers
their actual results as of most importance. With the
most intense sunlight with an illuminating system of
N..A. 0.3, and an observation system of N.A. 1.2, used
with strong oculars, the least value they obtained for
the edge of their cube-shaped gold particles was 4^/j.
(= .000004 m.m.) for bright spots on a dark ground.
For dark spots on a bright ground, on the basis of the
diffraction theory, with N.A. 1.5., wave-length 500 /x/t.
eye-sensitiveness limit 5 p.c, and a completely aberra-
tion free pencil, Herr Strehl himself has demonstrated
the following limits of visibility : — Smallest diameter of
round dark apertures, self-luminous 48 mm-, illuminated
34-5 MM-, and smallest breadth of straight dark slits,
self-luminous 10.5 fi/j.., illuminated 2.5 ^^. The com-
parison of both methods of observation, as well as the
results, has importance in connection with the investi-
gation after ultra-microscopic bacteria. Compare the
original statement in Central ZeiL f. Optik. u. Mech.
xxvi. (1905;, p. 117, :uid J.R..M.S. (1905), p. 521.

Imbedding with Incomplete Dehydration.

\V. J. v. Osterhout, Univ. California, Pub. Bot.,
and J.K.M.S. (1905), p. 526, recommends the use of a
saponaceous medium for imbedding vegetable tissues
instead of parallin, namely, cocoanut oil and sodium
hydrate nii.\cd in the proportion of 70 c. cm. of oil to
38.5 a cm. of 28 per cent, solution of KHO in water.
ITie oil is wju-med in a water-bath, and the lye added
gradually, the mass Ijeing stirred meanwhile. Tlie
tissue to be imbedded is warmed in a water-bath, arid
the soap added as long as it will dissolve. 'Ilie whole is
poured into a suitable receptacle until sulBcienlly firm
to cut into blocks. The birjcks are then treated as in
the para din methixl. Perfect sections, one micron
thick and several feet long, are easily obtained, llie
sections may be treated in the usual way, either by
making them adhere at once to slides, or by first dis-
solving out the soap by soaking them in water. If
required to be fi.xed to slides in serial order, they aro
placed on slides previously coaled with while of egg
and then dried ; they are then moistened with xylene,
w-hich spreads them out, and makes them adhere. A
piece of absorbent muslin is next pressed gently on the
sections, and when the xylene has evaporated, the
muslin is moistened with water. TTie slide is Mien
heated to coagulate the idbumen, and fix the sections
to the slide. The muslin is nf>w moistened again, :md
afterwards carefully removed, after which the sections
can be treated as usual. .Mcohol may Ije used instead
of water for imbedding by this nK-thcxI. The tissue
partly dehydrated is placed' in alcohol on a water-bath,
and soap added till no more will dissolve.

Microscopical Lectures.

The Manchester Microscopical Society have ag.iin
sent me their annual prospectus of lectures for the
coming winter, which are given by members of the
Society, for the most part gratuitously, save for out-
of-pocket expenses, in the districts around Manchesler,
and even in the Xorth-W'est Riding of Yorkshire and
the Western Counties. The list of lectures numbers
55, and of lecturers 19, and the lectures are given at
meetings of any society, science club, mechanics' in-
stitute, etc., which applies for them. Practical demon-
strations in microscopy, microscopical exhibitions, and
the moimting of microscopic objects are also gi\on if
required. So excellent a scheme deserves the highest
commendation, and might, with advantage, be imitated
by other societies. In particular, it seems to me that
the Quekett Club could well extend its usefulness by
adopting such a scheme as this. It would bring micro-
scopical matters before a larger public, would dissemi-
nate scientific knowledge, could not fail to increase the
numbers of those who are interested in microscopical
matters, and, incidentally, would make known the work
of the club, and bring it new members. What the
Manchester Microscopical Society can do in the popu-
lous districts in and around Miuichester could surely
not fail to be e\cn more successful in the densely popu-
lated district of London.

Glycerine a.s Bl Mounting Medium.

The use of glycerine as a mounting medium, con-
venient as it is in many respects, has several disad-
vantages. Pure glycerine has ; refractive index of
1.46, but, by diluting it with an equal quantity of water,
the refractive index is lowered to 1.4, and thus the
visibility of many structures is increased. It is im-
portant, however, that the object should be thoroughly
impregnated witli glycerine, and a fruitful cause of diffi-
culty is the presence of air bubbles in the tissues ; such
air bubbles, unlike those in objects mounted in Canada
balsam, not being subsequently absorbed. 'Hie essen-
tial difference between mounting in Canada balsam and
mounting in glycerine is that, whereas objects mounted
in the former medium must be thoroughly dehydrated
— that is, freed from every trace of water — objects
mounted in the latter medium must be mounted direct
from water only. It is advisable, therefore, to soak
the object carefully in water, and to use water that has
been recently boiled, to get rid of any air in it. /\fter
this, the object must be well soaked in glycerine until
every part of it is thoroughly impregnated. Glycerine
jelly contains gelatine, and requires to be melted before
use, after which it sets again ; Farrant"s medium con-
tains gum arable, and sets at the edges ; but glycerine
itself not only does not set, but is so hygroscopic as to
absorb water readily from the air. The mounts must,
therefore, be enclosed in some way — ringed, as it is
termed. The usual way is to centre the slide on a
turntable, and ring the cover-glass with a thin circle of
melted glycerine jelly, and, after this has set, to ring
again with one or two coats of gold size, llic gold
size must not be too thin ; in fact, it .should just be thin
enough to leave the brush easily, and no more. Any
other cement, such as zinc white or Urunswick black,
may then be applied on the top of the gold size.
Another, and less-knf)wn methfKl, is to ring in the same
way with Canada balsam instead of glycerine jelly.
The balsam, likewise, should be comparatively thick.
It is important, however, that both cover-£,'lass and
slide, beyond the border of the former, should be quite

October, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

259

free from glycerine, otherwise the balsam will not
adhere, and it needs some little practice to know the
exact amount of g-lycerine to use in mounting- so that it
will just reach to the edges of the cover-g-lass and no
more. Glycerine is able to find its way, sooner or later,
through most cements, but slides that I have ringed in
this way with Canada balsam some years ago are still
quite firm and sound.

Wa.tson*s New Model Microscope.

The Continental type of microscope has obtained so
firm a hold in our science laboratories Ihat many
teachers and students will not look at any other in-
strument than one possessing the familiar horse-shoe
foot, and upright bar carrying the limb and body-tube.
This is not the place in which to discuss the respective
merits of the English and the Continental microscope ;
this preference exists, and instrument makers have to
reckon with it. In certain cases they have done so, by
surrendering at discretion to the wishes of their cus-
tomers and, whilst admitting that the step is in many
ways a retrograde one, giving what is asked for by
supplying a microscope made exactly on the Con-
tinental model. Messrs. W. Watson and Sons have
attacked the problem in an entirely new and char-
acteristically original way. They have just brought
out a new microscope, which apparently follows the
Continental model closely, but which never-the-less
differs from it vitally. It has the horse-shoe foot, foot
and pillar being cast in one solid piece, but instead of
the upright triangular bar above mentioned, actuated
by a direct-acting micrometer screw, and bearing the
whole weight of limb and body-tube, the stage and
limb are also cast in one solid piece, and Watson's
well-known lever fine adjustment is retained, with all
its advantages, though the shape of the limb and the
appearance of the milled head are those of the Con-
tinental microscope. In other words Messrs. Watson
retain the essential advantages of the English lever
fine adjustment, and conform outwardly to the too
familiar Continental appearance. In all other respects
the microscope follows Messrs. Watson's usual type,
of which the well-known " Edinburgh Student's " and
" Fram " Microscopes may be taken as examples. The
new microscope is christened the " Praxis," and an
elaborated form is to be known as the " Bactil."
Concerning certain fittings of this instrument, I shall
hope to be able to say something next month. The
new microscope appears to me to be a most ingenious
method of meeting prejudice without yielding on the
reallv important principles of design. The names,
however, which Messrs. Watson choose for their
various instruments seem more open to criticism.

Distribution of Wood Pulp.

With reference to my recent article in this journal on
" Fibrous Constituents of Paper," by the kindness of
Mr. J. Strachan, of Ballyclare, I am able to offer, to any
of my readers who care to send me a stamped addressed
envelope, some samples of chemical and mechanical
wood pulps, such as are used in paper-making. To
these I can myself add a sample of a pure esparto
paper, and a sample of a brown paper containing hemp,
manila hemp, jute, and linen.

Notes a-nd Queries.

F. Oppenheimer (Chorlton-ciim-Hardy). — I see no impractica-
bility in your design for a fine adjustment to the sub-stage of
your microscope which can be actuated without moving the
hand from the fine adjustment of the body tube, but I am

afraid you will find it costly to make, and I question if the
advantage gained would be commensurate with the expense.
The sub-stage does not require frequent adjustment when one
is examining a slide — once adjusted for any particular slide it is
practically in focus whilst the whole object is being examined.
I may perhaps say that I myself use the fine adjustment to
the sub-stage a good deal, and I have never found the existing
arrangement in any way inconvenient. If, however, you pro-
pose to proceed further with the matter, I will make one or
two suggestions. The first is that the arc with diagonal rack
actuating the fine adjustment would be difficult to fit accu-
rately, and it would be simpler and equally effective were you
to have the lever pressed upon and so moved by the end of
the screw attachment of the milled head, space being left for
the milled head to travel vertically. Or you could fit a move-
able collar to this screw which could be kept from rotating
either by a pin or by a square fitting. The second suggestion
is that the screw part of the micrometer screw to the sub-stage
is quite unnecessarily long and elaborate in its mounting.

A.J. Attrid^c (Cape Town. S. .-!.).— I think the photo-micro-
graphs you send me are very good for early attempts, and the
mounting also is good, especially the Flea. The others, except
the blow-fly proboscis, might with advantage be a httle more
transparent. The illumination is equal, but the details are
somewhat insufficiently shown. For instance, in the blow-
fly proboscis the details of the suctorial tubes should be
more evident even with this low magnification and the fine
hairs on the membrane of the proboscis— those in the centre
space for instance, should be evident. I mention these
matters because it is only by attention to Mttle details of this
sort that one realizes the advantage of a really " critical "
image and rigid focussing. It is important to bear in mind
that such details are not best brought out by stopping down
the iris diaphragm of the condenser. This may at first glance
appear to increase the contrast, but in reality the whole image
is blurred and coarsened, the finer details are lost, and they
may even be surrounded by a sort of halo due to diftraction,
whilst the resulting print shows all such errors even more
clearly than they are seen visually. I would suggest also that
silver prints are less satisfactory for photo-micrographic work
than bromide papers, which give very sharp blacks and whites.
F. B. M. S. {ShfffteM}.—! think, perhaps, the best all-round
text-book on botany is Strasburger's, translated by H. C.
Porter, and published by Macmillan and Co. at iSs. net. It
is very good for morphology and physiology, but the descrip-
tive botany is scarcely full enough for use as a work of
reference. Without being too elementary it is also not too
advanced. For more advanced work you might read
Sachs or Goebel, and De Bary's " Comparative Anatomy
of the Phanerogams and Ferns," all published by the
Clarendon Press. For the naming of indigenous plants
the easiest book to use is Bentham and Hooker, pub-
lished by L. Reeve and Co. at los. 6d., with a supplementary
volume of illustrations at the same price, but the classifica-
tion is out of date, and now looked upon as unsatisfactory.
There can be no more delightful book to read thau Kerner's
" Natural History of Plants," published with profuse ilhistra-
tions by Blackie'and Co. in two thick volumes — it is more like
an interesting story than a book on botany. An excellent
book of its kind is Willis's " Manual of the Flowering Plants
and Ferns," published by the Cambridge University Press
at los. 6d. For practical work I think Strasburger's " Hand-
book of Practical Botany " is the most helpful to the private
student. It is published by Swan, Sonnenschein and Co. at, I
think, 8s. 6d., and contains very full and detailed descriptions
as to methods. Bower's " Practical Instruction in Botany "
is a well-known book. A very useful little book is Chamber-
lain's " Methods in Plant Histology," published by the Uni-
versity of Chicago Press, and which, I think, can be got
through Chapman and Hall, of London, at about 4s. I hope
from among these you will be able to obtain what you want.

ir. D. DaJe, A. H. Glaishcr, and Otiiers.—l am sorry that,
owing to its being vacation time, and to my having only just
returned from abroad, I am unable to answer your questions
this month, but I will try to do so next month.

[Communications and enquiries on Microscopical matters should be
addressed to F. Shillington Scabs, "Jersey.'' St. Barnabas Road.
Cambridge ]

26o

KNOWLEDGE & SCIENTIFIC NEWS.

[October, 1905.

The Face of the Sky for
October.

By W. Shackleton, F.R.A.S.
The Son. — On the ist the Sun rises at 6.1 and sets at
5-39 ; on the 31st he rises at 6.53, and sets at 4.35.

Sunspots are numerous, and recent spectroscopic
observations of the Sun's limb have shown many active
prominences.

The position of the Sun's axis and equator, required
for physical observations of the Sun, is indicated in the
following table : —

Date.

Axis inclined from N.
point.

Oct.

1..I

26°

10'

I ! . .

26°

28'

. I . .

26°

j; ..

24°

50'

The Moon :-

Equator S. of
Centre of disc.

37'

6°

5° 15'

4° 18'

Oct. 5

5 First Qaarter

54 P-m-

0 Full Moon

3 a.m.

d Last Quarter

51pm.

• New Moon

58 a.m.

Apogee 252,600 miles
Perigee 221. Soo

30 p.m.
30 a.m.

The Planets. — Mercury is a morning star during
the early part of the month, but the planet is not suitably
placed for observation, as he is in superior conjunction
with the Sun on the 12th.

Venus is a morning star in Leo and Virgo, and
throughout the month rises about 3 hours in advance of
the Sun. On the morning of the 8th the planet will be in
conjunction with the star x Leonis, passing about
10' to the south of the star. In consequence of increas-
ing distance from the earth the lustre of the planet is
diminishing.

Mars is a feeble object in the S.W. evening sky, set-
ting about 8.30 p.m.

Jupiter is now well placed for observation before mid-
night and is the most conspicuous object in the sky
looking E. about 9 p.m., being situated in Taurus about
midway between the Pleiades and Aldebaran. The
equatorial diameter of the planet on the i6th is 47"-o
whilst the polar diameter is 3"-o less. The following
table gi%'es the satellite phenomena visible in this
country, before midnight: —

P M.'5.

S =

P.M.'».

P.M.'n.

H. M.

i\ ^ t

M, H.

H. H.

Oct.

Sti. I.

9 50

15 II. Tr. I.

8 37

11.

Oc. R.

8 22

Tr. I.

II 0

II. Sh. E.

9 16

Sh. I.

10 0

III.

Oc. D.

'J 50

II. Tr. E.

II 9

»S

Tr. 1.

10 46

Oc. R.

10 I<)

lO I. Ec. D.

10 49

Ec. D.

7 12

III.

Oe. R.

II M

17 1 Sh. I.

« 7

Oc. R.

10 6

11.

Ec. D.

9 55

'. I

Tr. E.

7 24

II.

Tr. E.

8 47

■ '9

III.

Sh. I.

7 15

Sh. I.

II .M

T 12

III.

Sh. E.

9 2

I).

9 "

Its 1 Oc l(

8 20

III.

Tr. I.

10 15

10 40

20 Ml. Tr. K

8 12

III.

Tr. E.

II 35

P..

8 25

22 II. Sh. 1.

9 '9

II.

Sh. I.

II Sf>

', lb

II. Tr. I.

10 57

II.

Ec. D.

6 57

II. Sh. E

" 53

II.

Oc. R.
Sh. I.

10 38
M 54

■Oc. K. ;l. :
and "Tr. E
tha diw, tod

appearance of the SatellUc behind the diic, and
Tr, I." the Ingrcu of a transit acro«> the disc,
I " the iniire** of a Uaoait of the ihadow acron

Saturn is suitably placed for observation in the early
evening, being due south about 8. 20 p.m. near the middle
of the month. The planet is describing a short retro-
grade path in .Vquarius, but is at the stationary point on
the 31st; the moon appears near the planet on the
evening of the Sth.

The ring is well open, and we are looking on the
northern surface at an angle of 11 J'; the polar diameter
of the ball is i6"'8, whilst the major and minor axes of
the outer ring are 42" and S"-4 respectively.

Uranus is situated about 2° south of the star ^ Sagit-
tarii, the planet is on the meridian shortly after 4 p.m.,
and sets about 8.15 p.m. near the middle of tlie month.

Neptune rises about 9 p.m. on the 15th; and is due
south about 5 a.m. The planet is situated in Gemini,
is in quadrature with the Sun on the 4th, and at the
stationary point on the 14th.

Meteors : —

The principal shower of meteors during the month is
the Orionids.

Date.

Radiant.

Characteristics.

R.A.

Dec.

Oct. 8-29
(18 to 20 maximum)

92'

15' N.

Swifi, streaks.

Minima of Algol may be observed on the ist at
8.52 p.m., 4th at 5.41 p.m., 21st at 10.35 P-m-. and 24th
at 7.24 p.m.

Telescopic Objects : —

Double Stars : — 7 Arietis i'' 48"", N. 18" 48', mags.
4-2, 4-4 ; separation 8"-8. Easy double, power 30 ;
notable as being the first double star observed tele-
scopically.

7 Andromedae i*" 58™, N. 41° 51 ', mags. 2 i, 4-9, sepa-
ration io"'2. The brighter component is intensely
yellow, whilst the other is greenish blue. The fainter
star is remarkable for being a binary, the components of
which are now less than 1" apart.

NebuL/E : —

Nebula in Andromeda, easily visible to the naked eye,
and readily found by referring' to the stars /< and ■. .\ndro-
medre. Seen with a 3 or 4 inch telescope, it appears to
be an extended oval, which is in reality composed of
spiral streams of nebulous matter.

(32 M.) Nebula close to the great Andromeda
nebula, and situated about 2'' to the south. It is fairly
round, and appears somewhat like a star out of focus.

(18 1^) lies about the same distance north of the great
Andromeda nebula that 32 M does south ; it is faint, but
large and elliptical.

" Knowledge " on Bookstalls.

CoMi'LAl.Nis having reached the ollicc of the dilliculty
of obtaining " Knowledge " at certain provincial
shops and bfxtk-stalls, wc beg to say that the paper is
always published before the ist of each month and
should be on sale on that date. We cannot, of course,
be responsible for such delays, but when copies arc
ordered direct from the office they arc posted so as to
be delivered on the ist of the month. For rates vide
page vii. Under the new five-year rate, subscribers
get their copies post free for sd.

26 1

KDouiledge & SeleDtifie Nems

A MONTHLY JOURNAL OF SCIENCE.

Conducted by MAJOR B. BADEN-POWELL, F.R.A.S., and E. S. GREW, M.A.

Vol. II. No. 12.

iNEW SERIES.]

NOVEMBER, 1905.

r Entered at
L Stationers' Hall

] SIXPENCE NET.

CONTENTS.—See Page VI L

Bv I. E. Gore, F.R.A.S.

In the Second Epistle of .St. Peter there is a predic
tion of the destruction of the world by fire. It is a
matter of some uncertainty whether this epistle was
really written by the apostle Peter. There are no cer-
tain traces of it earlier than the 3rd century. Its
authenticity was questioned by Origen, and St. Jerome
says that many in his time rejected it. The difference
in style between the first and second epistle is so
marked that modern critics think it improbable that
the second epistle was written by St. Peter. But there
is "no consensus of opinion ag^ainst it," and as it is
now universally admitted into the canon of Scripture
we may, perhaps, accept it as genuine. However this
may be, it seems remarkable that in tlie great Sanscrit
epic poem, the " Mahabharata," there is a distinct pre-
diction of the destruction of the world by fire. In that
ancient work, the following passage occurs :* " O
King, towards the end of those thousands of years,,
constituting the four Ytigas, and when the lives of men
become very short, a drought occurs extending for
many years. .'^nd then, O Lord of the Earth,
men and creatures, endued with small strength and
vitality, becoming hungry, die by thousands. And
then, O Lord of men, seven blazing suns, appearing in
the firmament, drink up all the waters of the earth
that are in the rivers or seas. And, O bull of the
Bharata race, then also everything of the nature of
wood and grass that is wet or dry is consumed and
reduced to ashes. .'\nd then, O Bharata, the fire called
Samvartaka, impelled by the winds, appeareth on the

• From an English translation of the Vana Parva, by Pratap
Chandra Ray, CLE Second Edition, iSSj, p. 561.

carlh that hath already been dried to cinders by the
seven suns. i\m\ then that fire, penetrating through the
earth, and makin-.;' its appearance in I he nether regions
also, begetteth great terror in the hearts of the gods,
the Daiiavas and the Yaksluu. And, O Lord of the
Earth, consuming the nether regions, as aLso
evcrvthing upon this earth, that fire destroyeth
all things in a moment." etc. This agrees
with St. Peter's words, " The elements shall
melt with fervent heat, the earth also and the
works that are therein shall be burned up." Tlie idea of
"seven suns " in the above extract is also in curious
agreement with the words of the prophet Isaiah (chap.
30, v. 26), "Moreover, the light of the moon shall be as
the light of the sun, and the light of the sun shall be
sevenfold as the light of seven days in the day that
[he Lord bindeth up the breach of his people, and
healeth the stroke of their wound." .Assuming the
truth of these remarkable predictions, let us see how
the catastrophe of a general conflagration might be
brought about by the operation of natural causes with-
out the intervention of a miracle.

Some have supposed that suoli a catastrophe might
possibly be produced by an outburst of the internal
fires of the earth. But such an hypothesis— in itself
very improbable in a cooling- globe like the earth — is
directly opposed to St. Peter's words. He says : " The
heavens, '■= being on fire, .shall be dissolved," clearly indi-
cating, I think, that the fire is to come from the mit-
s/de ; " the heavens," not the earth, being on fire, is to
be the immediate cause of the catastrophe. Others
have thought that an outburst in the sun would, per-
haps, produce the conflagration, and this certainly
seems much more probable. Were the sun to suddenly
blaze up, like the "temporary stars," recorded in the
annals of astronomy, and of which we had such a bril-
liant example in February, 1901, in Perseus, then, of
course, the earth would certainly be burnt up, and at
least everything on its surface would at once be re-
duced to ashes. But, although this is, of course, within
the bounds of possibility, such a catastrophe is not, I
think, at all probable. There are, to be sure, small out-
bursts daily taking place in our central luminary, as m-
dicated by the "prominences," or red flames, visible

■ Here the word " heavens " means the earth's atmosphere.

KNOWLEDGE & SCIENTIFIC NEWS.

[November, 1905.

round the sun's limb during- total eclipses ; but these
are of comparatively small importance, and not likely
at any time to endang^er the earth's safety. An out-
burst on a much larger scale would be necessary to
produce anything in the way of a catastrophe which
would destroy all life on our terrestrial alxxle.

\ow is tiicre any cause which would produce a great
outburst of light and heat in the sun ? I think we have
such a cause in the possible collision of the sun with a
dark body in space. The distance of the stars is so
great, that the collision of the sun with a star is a con-
tingency which may be at once dismissed. Such an
event, if it ever took place, could not possibly happen
for thousands of years to come. To pass over the
distance which separates the sun from even the maresl
fixed star would take, at the rate of, say, 10 miles a
second, about 80,000 years !

The existence of dark bodies in space has been sus-
pected by astronomers. I say suspected, for really we
have no direct evidence that such bodies exist The
idea seems to have originated in the so-called "dark
companion " of the variable star .Algol. But we have
no evidence whatever that .Algol's companion is really
a " dark body," that is, a body devoid of all inherent
light of its own, like the earth. It is true that in the
case of Algol the spectroscope shows no sign of a
second spectrum, as in some variables of the .Algol
type in which both components are of nearly equal
brightness. But it has Ixjen recently found by Profes-
sor Hartmann that " a difference of only about one
magnitude would be sufHcient to bring the spectrum of
the fainter component to almost complete disappear-
ance, and a difference of two magnitudes would make it
impossible for even a trace of the fainter spectrum to
be visible on the plate." * The companion of Algol
might, therefore, be of the 4^ or 5th magnitude, and
neither telescope nor spectroscope would show anv sign
of its existence. But, apart from the above considera-
tions, it seems very probable that many dark bodies do
exist in space. In the ca.se of large bodies of this
kind, they would have their origin in cooled down suns,
."^tars cannot go on shining for ever. They commence
I heir course with a limited amount of potential energy,
and this energy is being incessantly dissipated in the
form of radiant light and heat. This dissipation of
energy cannot clearly g'o on continually, and in the
course of ages must become exhausted. It is like a
man living on his capital. If he receives no interest
on it, and goes on spending the money steadily, the
day must come, sooner or later, when the capital will
disappear, and the man will be reduced to a state of
bankruptcy. So it is with a sun. It can receive no
energy from without, and it is constantly wasting its
capital of energy in the radiation of heat and light.
It is true that this waste may be apparently compen-
sated for a time by the contraction of the sun's mass
due to gravity. But this is only the conversion of
potential energy into heat, and eventually the prtxress
must cease, as after a time — counted, of course, by
ages — the sun's density will lK;cf)me so great that the
contraction will cease, owing to the overcrowding of
the molecules, no further heat will lie pro<luced, and the
fKKly will begin to cf)ol down. When Ibis cor)ling prr>.
cess has sufficiently advanced, the sun will lose its
light, and " roll through space a cold and dark ball."
There is evidence to show that in some of the long-
period variable stars, this permanent waning of light
has already commenced, and it seems highly probable

• A iirophytital Journal, May. 1904

that, in many cases, the "cold and dark" stage has
been actually reached. These dark bodies may, indeed,
be very numerous, but we have no means of observing
them, as they show no light, and would not be visible,
even as faint stars, by the largest telescopes which
could ever be constructed.

It is now well known that the sun is moving through
sp.ice with a considerable velocity, :ind, of course,
carrying with it the earth, and all the planets and satel-
lites of the solar system. X'arious estimates have been
made of the point towards which the sun is moving,
but the most recent and accurate calculations seem to
point to a spot near the bright star Vega [a Lyr.-r).
In its flight through space it seems quite within the
bounds of possibility that the sun may .some day come
into collision with a dark body. Should such an event
occur, the collision would, of course, produce an enor-
mous amount of heat and light, .nul St. IVter's predic-
tion would at once be fulfilled. " The heavens " would
be " on fire," and the whole surface of the earth, and
everything on it, would be reduced to cinders in a few
minutes. It would be like the destruction of St. Pierre
on a colossal .scale. The world would end

" In unrcmorseful folds of rolling fire."*

But such a catastrophe could not occur without our
knowing of the coming disaster months, and perhaps
years, beforehand. When the approaching dark body
came within a certain distance of the sun it would
begin to shine by rellected light, like the planets. If
a very large body, comparable with the sun itself in
size, it would first become visible far beyond the con-
fines of the solar .system. l""or some months, or years,
its motion would be very slow, owing to its groat
distance from the sun. It would probably be
first discovered as a telescopic star, not differ-
ing in appearance from other stars of the
same brightness in its vicinity. It would then,
perhaps, shine as a star of about the glh magni-
tude, as any much fainter star would probably be over-
looked. Doubtless it would at first be mistaken for a
"new" or "temporary star," or a variable star at its
maximum brightness; but the comparative constancy
of its light, and its great parallax, or apparent change
of place among the neighbouring stars, would soon
reveal its true character, and show that it was really
near the earth compared with the distance of the
stars. It might, jiowcver, be mistaken for a distant
comet, but if coming directly towards the sun, its
change of place would be small, and its light examined
with the spectroscope would show a solar spectrum,
indicating that, like the plancl.s, it was shining by re-
flected sunlight. h"urthcr, its distance could be calculated
from its par.illax, and the result would show that no
comet would be visible at such a distance from the
Sim.

1 have made some c.ilculalions on the motion of this
hypothetical Ixxly after it became visible as a star of the
9th magnitude, and. therefore, e.isily visible in a tele-
scope of three inches aperture. I.et us suppose the
approaching dark body tr) have the same mass as the
Sim and the same density as the earth. T:d<ing the
earth's density as four limes that of the sun, and the
sun's di.-imeter as 866,000 miles, I find that the dia-
meter of the dark body would be about 546,000 miles.
Now, taking the diameter of Uranus as ,^,V<'oo miles,
its stellar magnitude as .s-7. and assuming that the dark

• Tennyson. Th( I Inly Grail.

November, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

263

body has the same "albedo," or light-reflecting power,
as Uranus, I find that the dark body would shine as a
star of t!ie 9th magnitude when at a distance from the
sun of 8.68 times the distance of Uranus, or about
15,000 millions of miles. Further, assuming that the
sun is moving through space at the rate of 11 miles a
second (about its probable value), and that tlie dark
body is moving directly towards the sun with the same
\elocity, we can calculate by the laws of Dynamics the
time taken by the two' bodies tO' come together, start-
ing with a distance between them of 15,000 millions
of miles. The motion for the first few years would be
comparatively slow, and, as I have said, the increase in
brightness of the dark body would at first be imper-
ceptible. To reduce the distance to 12,000 millions of
miles would, I find, take about 3.4 years. At the end
of 6.7 years the distance would be reduced to* about
9.000 millions of miles, and in 9.8 years to about 6,000
millions. At tliis distance the brightness of the dark
body would increase to about the 5th magnitude, and
it would then be distinctly visible to the naked eye. In
about 11.8 years the distance would be reduced tO' 4,000
millions, and in alxjut 14 years the dark body would
reach the orbit of Uranus, or, rather, it would be at
the same distance from us as Uranus, for its patii
would not intersect the orbit of the planet, as I will
.show presently. It would then shine as a star of about
— 0.4 magnitude, or a little brighter than Arcturus,
and would, of course, attract general attention. After
this its distance would rapidly diminish, and its light
quickly increase. After about a year from this time it
i\ould reach the distance of Jupiter. Its light would
then be greatly increased. It would appear as a star of
about — 6i magnitude, or about 4 magnitudes brighter
than Jupiter at its brightest, and about 2 magnitudes
brighter than Venus at her greatest brilliancy. It
would then be the brightest object in the heavens, with
the exception of the moon, and would be the " observed
of all observers." After this its motion would become
very rapid, and in about 51 days it would be at about
the same distance from the sun that the earth is. From
this point my calculations show that the velocity would
be very rapid, and if a direct collision took place the
sun and dark body would meet in about eight days,
the velocity of each body being then over 400 miles a
second ! The effects of such a collision may be easil}
imagined. Both bodies would be reduced tO' the
gaseous slate within an hour, and a stupendous amount
of heat would be produced — heat sufficient not only to
destroy the earth, but probably most of the planets
of the solar system.

If the dark body approached the sun in a straight
line, it could not strike the earth itself or any of the
planets, for the direction of tlie sun's motion in space
is inclined to the plane of the earth's orbit at an angle
of about 60 degrees. The nearest approach of the
dark body to* the earth would depend on the time of
year at which its collision with the sun took place. If
this occurred about the end of December the dark
body would not approach the earth nearer than the
su{i's distance, but if the collision took place about
June 21st I find that the body would approach the
earth within about 80 millions of miles. In the latter
case its attraction on the earth would be greater than
that of the sun, and it would probably draw the earth
out of its orbit. In either case, when the collision to' k
place, the sun's mass would be suddenlv douljled, and,
•according to Professor Young, the earth's orbit "would
immediately become an eccentric ellipse, with its
aphelion near the point where the earth was when it

occurred."'' Hut of course this alteration in the
earth's orbit wxnild not concern humanity after the
earth, and all its inhabitants, had been reduced to
ashes.

It is, of course, possible that the dark body would
not approach the sun directly in a straight line, but
along an elongated ellipse. In this case it would miss
striking the sun, and there would be no collision. But
the earth's motion in its orbit would be much disturbed
by the powerful attraction of the dark body, and it ij
not easy tO' determine what the exact result would be
If, however, the body were moving in a sufficiently
elongated ellipse to pass inside the earth's orbit, it
would probably pass close enough to the sun, to pro-
duce a great disturbance in that body, due to tidal
action, and a large amount of extra heat would
probably be developed. Should the two bodies merely
graze each other, an enormous amount of heat would
certamly be produced, quite sufficient to cause the
earth's destruction.

The approach of the dark body to the sun would
form a magnificent celestial spectacle. When it arrived
within the sun's distance from the earth it would, I
find, shine with about the same brightness as the moon
when full, but with a smaller diameter, and it would
rapidly increase in brightness of surface as it ap-
proached the sun. It would then — especially if the
approach occurred in the month of June — begin to
show phases like the moon, and we should have the
curious spectacle of two moons in the sky, one some-
what smaller than the other !

Instead of a dark body of the mass of the sun, we
may suppose one very much smaller, say of the size
of Jupiter. In this case, the masses being so un-
equal, the sun's motion would be much smaller. On
the other hand, the dark body would not become visible
until it was much nearer to the earth. In the case of a
body like Jupiter, say 87,000 miles in diameter, I find
that it would become visible as a star of the 9th magni-
tude at a distance of about 3A times the distance oi
Uranus from the sun, or about 6,000 millions of miles
from the earth. If the diameter of the dark body was
the same as that of the earth, it would shine as a star
of the 9th magnitude at about the distance of Uranus,
and in this case it would fall into the sun in about three
years. The amount of heat produced by the collision
would, of course, be very much smaller than in the
cases just considered, but it seems very probable that
even a body the size of the earth, moving with such a
high velocity, when it struck the sun would produce
the most disastrous results to the earth. Such a body
may possibly be now approaching us. If only the size
of the earth, it might easily escape detection until well
within the orbit of Uranus, and we might then have
only a few months' warning before the final catastrophe
occurred.

But, it may be asked, is there any star visible at
present which might be identical with an approaching
dark body? Well, all I can say is, that I have care-
fully examined the region round Vega with a powerful
binocular field glass, and that at present (.April, 1905)
there is no star brighter than the 7th magnitude within
five degrees of Vega, which is not perfectly well known
to astronomers. A careful examination with a 3-in.
telescope, or, better still, a photograph of the region
would be necessary before a decided opinion could ne
formed on the subject.

' Maniial 0/ Astioiwiny, p 294.

264

KNOWLEDGE & SCIENTIFIC NEWS.

XoVEMliliK,

1905.

InflvienzsL arvd the
Weather.

IJy Arthur H. Bell.

Scapegoats are always in fashion, for ;it all times
people have shown a strong tendency to put the blame
for the ills to which humanity is heir on something or
somebody. The bills of mortality, for instance, as
soon as ever winter comes grow enormously long, and
in looking round for an explanation of this unusual
increase it seems the most natural thing in the world
to set down the ills of the community to the account of
the weather. Influenza, especially, is thus ascribed
to the vagaries and pranks of the British climate, but
an examination of the facts gives but little support
to this popular belief, and it may, indeed, be shown
that the scapegoat on this occasion is burdened with
misdeeds from which it should properly be free.

The particular variety of the British climate summed
up under the heading liast Wind has, for example,
more particularly been objurgated and anathematised
as a breeder of the influenza; but since meteorologists
have been studying the anatomy and character, so to
speak, of this much maligned wind they have come to
the conclusion that the advantages derived by its bene-
ficent action on the land are to be counted as a set-off
against its undoubted untoward effects on man and
beast. The East Wind, among other good deeds, ex-
tracts all the moisture from those land surfaces over
which it blotvs, and so breaks up the soil and puts it in
better condition for the sowing of seed, and in this
way large tracks of country are, from an agricultural
point of view, improved and brought into good condi-
tion. This wind it is that breaks up the soil and
pulverises it, this beneficent action being recognized
by the old proverb that says, " .\ peck of March is
worth a King's ransom."

In passing it may be said that the liast Wind, which,
like the Gulf Stream, may almost I^e called a national
institution, is, however, mainly to blame for chapped
hands and reddened and roughened cheeks so much in
evidence when this wind is streaming through the air.
That it has the.se effects on the human cuticle is due
to the fact of its being a dry wind. All the moisture,
indeed, is taken from it as it journeys across the frozen
plains €>f .Northern Europe, so that notwithstanding
its sub.scquent journey across the North Sea it is still
very dry by the time it reaches the British Isles. As a
result it sucks up water wherever it is to be found,
and, as already mentioned, it is from the land that it
takes much of the moisture wherewith it quenches the
thirst induced by its long journey. But like so many
other surfaces the skin of human beings is constantly
giving off moisture, and as the thirsty wind comes
along it promptly avails itself of these stores wherever
it finds a hand or a cheek exposed to it.

Moreover, it is well known that according as there
is little or much vapour in the air, so is the passage

through the atmosphere of the heat from the sun
assisted or retarded. Bearing this elementary fact in
mind it will be understood that since the air is very dry
when the East Wind is blowing, the sun's rays readily
pass through the air, and hence arises the redness im-
parted to hands and faces on cold and frosty morn-
ings. Those who have been on the snow on the top of
high mounlains will readily call to mind the way in
which their skin was reddened by the sunshine as it
came uninterruptedly through the cold air. The whole
of the blame, therefore, fo.- red noses, chiibl.'iins, and
chapped hands is not rightly to be given to the East
Wind, for the sun also bears much of the responsibility.
But the influenza in the popular mind is so intimately
associated with chappt'd hands that it seems a ready
way out of the dilliculty to say that the East Wind is
to blame for both. This aspersion on its character
has, however, never been proved, and until a stronger
case is made out the East Wind ought not to be used
as a scapegoat.

.As a matter of fact, climatic conditions appear to
have only a secondary effect upon visitations of the
influenza epidemic. It seems, indeed, to visit the
regions round the Poles as impartially as it does those
at the Equator, and the Hottentot and the Esquimaux
mav, as it were, be said to sneeze in unison. Sunshine
would seem to have as little to do with its comings and
goings as does the dampness or dryness of the air.
The records from the rain-gauge and the hygrometer
have, from this point of view, been compared with the
statistics of the influenza scourge, and when this is
done no agreement is found between them. Meteoro-
logists, moreover, now know that different types of
weather are associated with two forms of distribution
of atmospheric pressure, one of these forms being called
cyclonic and the other anticyclonic. With the cyclones
the winds are circling strongly upwards and the
weather is stormy, rainy, and altogether unpleasant.
In the anticyclones, on the other hand, the winds are
circling downwards from the empyrean, and they bring
halcyon days and bright, exhilarating, cheerful
weather.

Now there was once a theory which informed a
suffering humanity that their sneezes and wheezes were
due to the fact that the influenza germs were generated
bv hundreds of dead Chinamen drowned in one of those
disastrous Hoods which so frequently occur when the
mighty rivers in the celestial empire overflow their
banks. The meteorological data, however, proved
very conclusively that the wind over these areas blows
very regularly in quite the contrary direction necessary
to carry the influenza germs to Europe; and those who
wished to throw blame on the wind and the weather
had accordingly to cast around for another theory.

The new statement of the case asserted that the
influenza was provoked by the dust thrown out by
volcanoes, and in one particular year it was confidently
ascribed to the tremendcjus volcanic eruption which
occurred at Krakatoa in the Straits of Sunda. During
this memorable leaping forth (jf the subterranean fires
the quantity of dust thrown into the air was un-
doubtedly very great. Moreover, all those beautiful
sunsets, afler-glows, lunar and solar corona;, and
haloes seen in abundani-e at this period were allowably
to be attributed to this great cataclysm, and since, more-
oxer, influenza was very prevalent just at that time,
nothing was easier than to assign its presence to this
volcanic outburst in .South-East Asia. At this time
also, as shown by the meteorologica] charts, anti-
<:yclonic conditir>ns prevailed over the British Islands,

November, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

265

and since, as already mentioned, the breeze would then
be descending from above, the theorists maintained that
everything; was favourable for the conveyance of the
hypothetical germs to the bronchial apparatus of a
susceptible humanity. But this method of inducing
influenza is something similar to the process of burning
down a house in order to- procure roast pig. Influenza
germs may, unfortunately, be sown without such a
display of molecular energy as occurred at Krakatoa,
and volcanoes therefore played the part of scapegoat
during but a short time. Pumice stone as a suggested
source of influenza has, notwithstanding the recent
volcanic purturbations, therefore, been abandoned.

Now the great objection to all these theories which
demonstrate how the influenza is wafted about by the
breezes is found in the fact that people in isolated posi-
tions escape the scourge. For instance, lighthouse-
keepers, the inhabitants of certain islands, and people
on board ships that do not touch land during lengthened
periods are not attacked, which they would hardly fail
to be were the influenza floating about in the air
promiscuously. Prisoners are, as a body, remarkably
free from visitations of the epidemic, and serve as a
modern instance to disprove the assertion that the
weather is at fault. From this point of view it would
appear that the best method by which to escape
influenza is to break one of the laws of one's country
and so secure a moderate period of solitary and isolated
confinement.

What seems clear is that the influenza travels from
place to place much more quickly than was the case in
former years, so that an outbreak say, in Buda Pesth,
rapidly journeys to London. As facilities of travel have
increased by rail, road, and river, so have the
peregrinations of the epidemic been correspondingly
accelerated. Investigations indicate very unmistakably
that where the stream of travelling humanity is greatest
there also is influenza most easily disseminated. It is
near the towns that microbes, bacilli, and other ob-
jectionable things have their birth, and although the
state of the atmosphere may at times be favourable for
their transportation, long journeys through the air are
fatal to them, for the sun and the wind rob them of
their venom. " No climate in the world," said King
Charles, " invites a man to walk abroad so many days
in the year as the climate of England," and despite
the popular impression concerning influenza and the
weather, a walk along some country road, or over some
wind-filled moor or common is, after all, the surest way
to reduce the proportions of the doctor's bill.

As already remarked, different types of weather are
associated with anticyclonic or cyclonic conditions,
and as regards the latter class of atmospheric vortices,
it is possible to trace the track or route they pursue as
they journey across the country, the history of their
travels being nowadays recorded in the meteorological
weather charts. Commonly these storms cross the
British Isles in a north-easterly direction, a favourite
line of travel being by way of the Caledonian Canal.
Now the path taken by the influenza as it passes from
town to town bears no sort of relation to the track of
the cyclones, which are the chief breeders of damp,
cold, windy and rainy weather, and a contemplation of
this fact gives no colour to the notion that influenza
flies as an arrow by day on the wings of the wind. It
is, indeed, not in protecting one's self from the health-
giving winds that influenza is to be averted, but rather
by a frequent overhauling of the dust-bin, and by
taking, as often as possible, a course of sun-baths.

Abnormal FolioLge of
Sycamore Seedling.

By Graham Bott, I-'.L.S.
The accompanying illustration (Fig. i) shows a rare
abnormal growth of the first pair of foliage leaves of a
Sycamore seedling. It will be noticed that complete
fusion of the petioles has taken place, and that this
fusion has extended tO' the leaves themselves along the
lower tvvo^thirds of their margins, thus forming twin
leaves. When compared with a normal seedling (Fig.
:), the anomalous condition is strikingly noticeable ;
and, since growth proceeds from the angle formed by
llie leaf-stalks, it is interesting to speculate as to what
would have happened in the abnormal form, with re-
ference to further development, had growth been

Fig. I.— A Sycamore Seedling showing twin leaves (natural size).

allowed to continue ; axillary orientation having been
arrested by the union referred to above.

It is, of course, recognised that several plants ex-
hibit cohesion of the margins of their leaves as a fixed
character, and, according to the degree of union, desig-
nated by various terms. But it may not be quite so
familiar that many leaves of the same plant show in-
teresting transitional conditions from the simple form
through variously lobed (connate), up to the completely-
divided compound leaf, such as may be found on the
Blackberry {Riibus fruticosus) and Cinquefoil {Poienlilla
reptam). Partial union is observed readily, also, be-
tween the terminal and one of the lateral leaflets of the
Ash {Fraximis excelsior). And a similar fusion of the
leaflets of the Scarlet Bean {Phaseohis) occasionally
occurs, thus transforming the compound leaf into a
simple one.

However, those instances are considered as reversion
to type, and it is strong presumptive evidence of the
evolution of the compound leaf from a simple form.

266

KNOWLEDGE & SCIENTIFIC NEWS.

[November, 1905.

But the peculiar instance of the twin leaves illus-
trrited can scarcely be explained on the above lines,
and, although it is often impossible to penetrate
Nature's mysterious influences determining changes of
form, nevertheless, the following explanation is sug-
gested.

Lack of moisture, followed by excessive supply,
causes, on the one hand, an arrest of development, and,
on the other, rapid growth. Retarded growth favours
fusion, and (in the case of a floral member, at least) a
symmetrical condition is brought about by an abundant
supply of nutriment. Pressure on the growing point
would, probably, play an important part also in causing
fusion, owiniT to the delicate nature of the primary
tissue.

t^lZ- 3.- Normal Syctmore Seedling: (two-thirds natural .si/e).

Now, when the circumstances are considered in
which the present specimen grew, it is found that all
the aljove conditions were fulfilled. It is, therefore,
reasonable to suppose that the above explanation is
the correct one.

It will be observed that both cotyledons are present,
otherwise the suppression of one might have
been a determining factor in producing the irregular
seedling. The specimen was found, by the author,
growing on a gravel path near a stone wall, on the
south side, during a dry spring, followed by a wet
summer. Thus the fact of its adverse environment and
irregular nourishment resulted in the inability of the
young tissue to work out its hcrcdilnry inclination, or
to follow that mysterious ancestral impression which
has determined ;'ll form', tlirdnflioni ilu rminilf^^
aons of the pas'

Whott is Scent?

By Dr. J. G. McPherson, F.R.S.E.

A DICTIONARY will Say that " scent is that which,
issuing from a body, affects the olfactory nerves of
animals." But that is not a complete definition. For
the issuing source of the scent may be solid or gaseous.
Until very recently it was assumed that there were
solid particles of the perfuming body to produce the
effect.

And certainly that theory has unduly startled think-
ing f)eople as to the extraordinary divisiiiility of
matter. We are faced bv very startling facts ; but it
is a stretch of the imagination to account for them by
the ordinary matter-divisible theory. The tenth part
of a grain of musk will continue for years to fill a
room with its odour, and at the end of that time will
not be appreciably diminished in weight by the finest
balance. So acute is the sense of smell in some
trained men that one part of prussic acid can be de-
tected in about two million parts of water; and it has
no decided smell, only a strange fustiness.

The faculty of scent is very acute in certain insects.
If a virgin female of the moth known as Sattirnia
Carpini is shut up in a box, males of the same species
will trace her out for a mile through the parti-odoured
air of a wood. The infinitesimal emanation from the
female is powerful enough to direct the male all that
distance. All are familiar with the remarkable scent
of the condor for carrion in Eastern countries, but the
scent of dogs seems to eclipse all in its marvellous
effects.

For ages it was considered certain that the musk
and other scents exist in the air after they leave their
visible form in solid particles. Now, Dr. John
.'\ilken, F.R.S., has, by experiments, pro\cd that these
pass off as a gas or vapour. He has principally em-
ployed his w^ell-known cloudy-condensation test. If
the musk is in solid particles, these particles will be-
come nuclei of cloudy condensation in super-saturated
air, and thus make their presence visible. But this
is not the case.

.^s to cloudy formation in general ; ocular demon-
stration can easily testify to it. If two closed glass
receivers be placed beside each other, the one con-
taining ordinary air, and the other filtered air (that is
air deprived of its dust, by being driven through cotton-
wool), and if jets of steam be successively introduced
into these, a strange effect is noticed. In the vessel
containing common air, the steam will be seen rising
in a dense cloud, but in the vessel containing the
filtered air, the steam is not seen at all. Dust-particles
are necessary in the air to allow v.-ipour-condensation
on the free surfaces, so as to form cloud-p:irticles.

Dr. Aitkcn has given us a simple method of showing
that the solid particles in the air seem to have a lower
limit to their siz->, but that they are never so small as
to be capable of diffusing or not being separated but
by the action of gravitation. If a glass flask contain-
ing common air be provided with an india-rubber
stopper, which has two apertures in it, in which are
fitted two tubes, one of these tubes is connected with
an air pump, and the other with a cotton-wool filter,
a stop-cock being introduced in the latter. .\ little
water is put in the flask to moisten the air. If the
stop-cock is closed and the pinnp-handlc is pulled out
a very short length, cloudy cf)ndensation at once takes
place, the very smallest expansion being sullicient to

November, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

267

cause the dust nuclei in the air to become centres of
condensation, and that is the case even with the very
smallest dust-particles.

If part of the cotton-wool be taken out of the filter
and only enough be left to keep back all but a few-
particles, and these of the very smallest size, yet
these require but the very slightest expansion to make
them visible. If the process of successive expansions
be continued, no further condensation is observable.

Now, introduce a little musk into the flask. If the
musk gives off solid particles, cloudy condensation
would at once take place when the air is expanded by
drawing- the handle of the air-pump, because the musk
would keep up a constant supply of nuclei of con-
densation. But it is found that instead of that, the
condensation is scarcely visible at first, and finally
ceases, as if no musk were present at all. In conse-
quence, it is determined that musk does not give off
solid particles.

Varying this experiment. Dr. Aitken considered that,
if musk passes into the air as a gas or vapour, it would
be able to pass through a quantity of cotton-wool
sufficient to stop all dust-particles. He first passed
air over the musk, then through the cotton filter, with
(he result that the perfume came freely through the
cotton-wool. Some of the gas which first entered the
filter was trapped and held by the wool, but the wool
soon became sufficiently saturated to allow the musk-
vapour to pass. The trapped vapour remained in the
wool and could easily be detected afterwards.

He also tested other odorous solid substances by
the same simple apparatus, such as camphor and
naphthalene. These both acted like musk and gave no
nuclei of condensation, and the gas or vapour from
both passed easily through cotton-wool. It is, there-
fore, safely concluded that they, like musk, evaporate
in gaseous form. Quite conclusively, Dr. Aitken has
similarly tested twenty-three substances ; not one of
them gave off their perfume in solid particles, nothing
but gases or vapours escaping from them.

By repeated experiments. Dr. Aitken has come to a
remarkable conclusion, which will be interesting to
sanitarians, viz., that sewage does not communicate to
the air any solid particles. The offensive emanation
is a gas. The air in sewers is remarkably free from
germs of all kinds, as they do not leave the sewage.
If sewage gave off solid or liquid particles, these also
would soon settle on (he surface of the sewage. If,
however, it be made to flow rapidly over falls,
then both germs and particles of the sewage get mixed
up with the air, but when the sewage flows without
break in its surface film, the offensive emanation is in
the form of a gas.

This revolutionary theory will take some trouble to
crush. And it will in future save the sensitive feelings
of those who have been unduly puzzled with the ex-
treme division theory of matter in the case of con-
^•eying scent from the perfumed body.

Sta-r Ma-ps.

We regret that, at the last, it is not possible to bring
out a star map supplement for this number. Not
satisfied with the results of the process hitherto em-
ployed, we have been testing new methods, which, it
is hoped, ^vill give much better results. The (rials,
however, have not been completed in time for this
month, although we hope with the December issue to
continue the series.

SugOLr.

By Dr. F. MoLtwo Perkin.

Although the sweetness of most fruits is attributable
to their sugar content, there are comparatively lew
which contain saccharose, the sugar which, in this coun-
try, is generally called cane sugar. Of all plants which
contain saccharose, the largest quantity is found 'n
the sugar cane, as may be seen from the following
list : —

15 to 20 per cent.

Sugar Cane Saccharbiiim offiihuiiiim

Sugar Beet Betii vulgaris

Sorgo, Soi'gliiim sacchaiatiim

Pine Apple

Sugar Maple, Acer Scuclniiiiiinii

Strawberry

Apricots . .

It is also found in small quantities in some varieties
of birch, palms, and in maize stalks. Most other
plants contain either grape sugar (dextrose), or fruit
sugar (laevulose).

Cane sugar seems to- have been first Known to- the
Chinese, at any rate, they knew of the sweetening pro-
perties of the sugar cane, although it is doubtful
whether they actually prepared crystallised sugar. At
the time of Alexander the Great, sugar was brought
into Greece, and the Grecian doctors employed it in
medicine for curing all kinds of disease. The crystal-
lised sugar appears to have been first prepared during
the 7th century A.D., and was manufactured in Persia
in the 8th century. The preparation of sugar and the
cultivation of the cane followed in the steps of " the
conquering Moors," during the 9th and loth century,
when it was introduced into Sicily and Spain. Fig. i.,
taken from an old engraving, shows the manufacture
of cane sugar in Sicih' in the year 1570.

In the i5(h and T6th century it was introduced by the
Portuguese and Spaniards intO' Madeira, Brazil, and the
Spanish West Indies. From this time on the cultiva-
tion of the sugar cane in the tropical countries, and
(he production of sugar, became a greater and greater
industry. Many refineries of the raw sugar, obtained
from abroad, were set up in Europe, and continued to
flourish for many years, until, in 1806, Napoleon pre-
\ cnted (he importation of the raw product. This practi-
callv killed (he cane sugar industry on the Continent,
but it resulted in the initiation of the beet sugar manu-
factory, which to-day is playing such havoc with the
cane sugar industry. In this article the cane sugar
industrv will be first dealt with, as it is of greater
antiquity, and also because the methods employed are
simpler than tluisc in operation in the beet sugar
manufactory.

The chief cane sugar producing districts are Cuba,
Java, Manilla, Mauritius, the West Indies, Northern
India, North America, Brazil, Japan, China, Egypt,
and the Sandwich Isles. In India it is being intro-
duced with the hope that the cultivation of sugar, and
its manufacture, may, to some extent, take the place of
the waning- indigo industry.

The sugar cane, as has already been shown, may,
under favourable circumstances, contain from 18 to 20
per cent, of sugar, but when the agricultural and cli-
matic conditions are not favourable, the amount of
sugar may not be more than 15 per cent., as, for
example, in Louisiana. The sugar cane belongs to the

268

KNOWLEDGE & SCIENTIFIC NEWS.

[November, 1905.

family Graminea. TTie outside of the cane consists of
a hard, woody envelope, the interior consisting- of a
spongfy mass of cells, between which the saccharine
sap circulates. The leaves form at the very hard
nodes, and each node is furnished with an eye. It is
from these eyes that the plant is propag-ated. ITie
cultivated plant does not bear seeds, so it, therefore,
cannot be reproduced except by means of cuttings.
The wild plant, however, reproduces itself by means
of seed, but the wild cane contains very much less
sugar than the cultivated variety. Fig. 2 shows the
sugar cane. A, the incrustation of wax on the epidermis,
highly magnified ; B, the fioret.

\\hen the cane has been harvested, the stubbles are
left in the ground, and will again yield an abundant
harvest, if the soil is kept in a good condition.

-After the cane has been cut, it is taken to the mill,
and should be crushed as soon as possible, because if
left some time before crushing, the yield of sugar be-
comes less, and the quantity of glucose increases.

TTiere are two methods for obtaining the sugar from
the cane : i. Crushing by means of heavy rollers ; 2,
Diffusion.

Milling, or Crushing Process. — Tlie cane, after strip-
ping off any foliage, is passed through heavy mills,
which consist of cast-iron rollers; it is then soaked in

Pis. I.

Tlie pieces of sugar cane, about a foot in length,
which contain the bud, or eye, arc planted in furrows
about six to eight inches apart ; they are then
covered with lo<:>se mould. .After a period of from
seven to twenty days, varying according to the variety
of the cane, the age <A cutting, and the weather con-
ditions, the buds sprout, rf>otlets are sent into the soil,
and the stalk and leaves begin to form. At the end of
from 10 to 13 mr)nths, the cane has reached a height of
seven to 15 feet, contains its maximum of sugar, and
must be cut. If the rane is left too long, the quantity
of sugar juice rapidly derreasj-s.

For cane growing, the soil should be fertile and well
tilled, but in a great many cases the growers neglect
even the elementary principles of agriculture, keep
their fields in poor cultivation, and without any manure
whatsoever; they then seem surprised that they obtain
a poor yield of sugar.

water, ;md ag;iin passed through a rolling machine.
Although the pressure exerted is very great, yet, owing
to the rane being mf>re or less elastic, and the centre
portion being of a spongy n:iture, as it passes from the
rollers it immedi.ilely al)sr)rbs a portion of the juice
which has been expressed, hence the necessity of a
second crushing. l-'ig. 3 shows diagraniin:ilic:illy .'i
section of a mill.

It consists of three cast-iron rollers, \. M, C". which
arc rotated by means of ge.iring, the spe<'d of revolu-
tion being two to three revolutions per niinutc. I) is
an inclined table upon which the canes are pl.'ired. they
pass down betwwn the rollers A and M, :ind then along
the inclined guide Iv, between H and C, the expressed
juice running into r-ctllcrting gutters, llic crushed
ni.iliri.il, or hagasse, is carriefl by me;ins of a conveyer,
through washing tanks, and from these tanks to
another series of rollers, or sf)metimcs between two sets

November, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

269

of rollers. The bagfasse is dried and used as fuel, be-
cause in most places where sug'ar cane is manufactured
fuel is expensive and difficult to- obtain.

The juice, as it comes from the presses, is sometimes
an opaque straw-yellow coloured fluid, but is often of a
greyish-ifreen. It usually contains a considerable
quantity of suspended matter, which requires to be

(.J— Incrustation of wax on epidermis,
Fig. 2.

lagnificd. Z>— Floret.]

separated, such as fibres from the cane, albuminous
matter, sand, and clay, etc. Owing-, however, tO' its
slimy nature, filtration is by no means easy.

In order, therefore, to clarify the juice, it is treated
with lime. There are two processes of liming-, defeca-
tion— in which only a small quantity of lime is em-
ployed— and carbonation, where an excess is added,
and afterwards removed by passing in carbonic acid
g-as. The addition of the lime neutralises the free acids
in the juice, thus preventing inversion, i.e., conversion
of the saccharose into glucose, when it is subsequently
heated, and it also combines with the albumen. .A.ll
these insoluble materials enclose the solid impurities
already in the juice, and carry them down as they are
precipitated.

Before adding lime, the juice is heated in steam-
jacketed pans to about 80°. Milk of lime is now added
in the requisite quantities, the mixture is then brought
to the boil, when a scum which contains many of the
impurities, rises to the surface, and is skimmed off.
The middle layer of the juice is found tO' be quite clean,
the upper layer is turbid, and the lower layer contains
the main portion of the precipitated matter. The
three layers are drawn off separately, the upper and
lower ones being passed through filter presses.

The defecated juice is now ready for concentration.
The old and wasteful method was to heat the juice in
a series of pans over an open fire. This was wasteful,
because of the large amount of fuel required, and be-
cause of the possibilities of burning the syrup.

The syrup to-day is, almost invariably, evaporated

in vacuum pans ; the syrup from the beet always. '1 he
amount of fuel used in France, with the old, open-fire
method, for 1 ,ooolbs of beets, was 40olbs., to-day, less
than loolbs. of fuel is required. The most modern and
satisfactory system of evaporation in vacuum is known
as the multiple effect, it was invented by the Franco-
American Rillieux. The system is shown in Fig. 4. It
consists of three evaporating pans, C, C, C, the con-
denser D, and the pump P. Steam at about 7lbs. pres-
sure is let into the heating tubes of the pan furthest
away from the pump — the tubes are covered with the
syrup to be evaporated. The steam causes the sug-ar
solution to boil. Owing to the vigorous boiling, and
noco«densation, there is not xery much vacuum in this
pan, but the steam from the evaporation passes into
the heating system of the next pan, where there is a
greater vacuum, therefore, the juice boils at a lower
temperature. The steam from this pan now passes
into the heating: system of the last pan, which is under
a very considerable vacuum, consequently, the juice
boils at a much lower temperature, and the steam from
it is continually condensed by passing into a well cooled
condenser. All the pans are connected together by
cocks, so that the juice can be run from one pan to the
other. During the evaporation this is done continu-
ously.

When the juice is sufficiently concentrated, it is
pumped out of the last pan. During the evaporation
many substances held in solution by the clarified juice
separate out, so that the juice becomes turbid again.
It is very important to remove these impurities, be-
cause they become enclosed in the sugar crystals during
the subsequent boiling process. The juice does not
filter well, so is usually purified by boiling the syrup in
eliminating pans, and treating with caustic soda or
sulphurous or phosphoric acid, as may be found
necessary.

The next process is the boiling, or final concentra-
tion of the syrup. This is usually done in single
exaporating pans. The .syrup is drawn into the pan,
which is generally of iron, and contains coils for heat-
ing purposes. The boiler requires toi be a man of great
experience, because the yield and grain of the crystal-

lised sugar depends entirely upon manipulation. It is
not easy to explain shortly the manner in which this
important process is carried out. For obtaining a
sugar of averag-e size grain, the procedure is essentially
as follows : The syrup is drawn into the pan, which is
under a vacuum of about 24 inches, the boiling point
will then be about 60° (140° Fahr.). Steam is gradually

I JO

KXOWLEDGE lS: SCIENTIFIC NEWS.

[November, 1905.

admitted into the coils as the syrup covers them.
At the begrinningf boilini^f is very brisk, but as the con-
centration increases, it becomes slower. When the
boiler considers the concentration suflicient, he lessens
the supply of steam, and increases the vacuum, by this
means the temperature of the contents of the pan fall
to about 50°. The syrup is now supersaturated with
sugar, and crvstals commence to form. .\s soon as no
more sugar separates, more steam is admitted, and a
fresh quantity of syrup slowly drawn into the pan.
When the pan is full, the supply of syrup is stopped,
and the contents concentrated. Tlie exact concentra-
tion, or striking- point, has to be found l)y experience,
and is determined by the firmness, a sample taken out
of the pan by means of the proof-stick, acquires, when

suddenly cooled in a pail ot cold water. 'l"he mixture of
crystallised sugar and molasses is now cooled, and
then, after being stirred in a mixer for some hours to
promote crystallisation, the porridge-like mass is centri-
fuged ; this process removes the molasses, and leaves
the hard crystals behind. The sugar is finally dried
in revolving iron cylinders fitted with steam coils. It
is then packed, and is ready for the market.

Diffusion Prccess. — The principle of the diffusion
method is based on the property possessed by certain
bodies, when in solution, of passing through a mem-
brane ; if on the other side of the membrane, a liquid is
present, which contains a smaller quantity of the body
in question in solution. This process of diffusion will
^o on until the concentration of the solution on botl
sides of the membrane is the same. Now, crystai-
lisable substances, such as sugar, have this property,
but gummy substances and albuminoid matter have not
this power, or possess it to a very small extent. The
process of diffusion is usually called dialysis. Now, in
the living cell of the sugar cane, the protoplasmic tegu-
ment of the cell is not a dialytic membrane, but if the
cell is killed, it then becomes a semi-permeable mem-
brane, i.e., is permeable to the one substance, but im-
pervious to the other.

In the actual working of the diffusion process, the
protoplasmic cell is killed by heat. 'ITie process is
briefly as follows : The cane is cut up into small sec-
tions, which are placed into large vessels called c^iffu-

sors, where hot water is poured upon them. The cells
are killed, and then the sucrose, glucose, the acids, and
certain inorganic substances diffuse through into the
water. .\.lter a lime, when a certain proportion of the
sugar has diffused out, the sugary water is run off,
and is replaced by a fresh quantity of water.

The first diffusion juice is poured on to a fresh cjuaii-
tity of slices, and this process of drawing off and pour-
ing upon fresh slices is continued until the diffusion
liquor linally becomes so far enriched that no further
diffusion takes place. The juice so obtained is then
concentrated and treated in the same manner as already
described. The diffusion process is not used to any
great extent in the cane sugar industry, although a
very thorough exhaustion of the juice takes place.

A great advantage with the mills is that their capa-
city permits greater variations of output than is the
case with tjie diffusion battery, l-'or example, it is
quite possible, in times of pressure, to crush as
much as 600 tons per day with a milling plant only con-
structed to crush 450 tons. There are, however, ad-
vantages in diffusion, the extraction is more thorough,
the juice is more casilv worked, because most of the
impurities remain in the bagasse, and finally there is less
danger of breakdown than in the case of machinery.
We will describe the diffusion process more exactly in
its applications to the beet sugar industry, w hi.rc it
plays a most important role.

Exhausted Hlo/asses. — A question of considerable im-
portance to the sugar producer, is what to do with his
molasses, which remain after the sugar has been sepa-
rated, and from which a further quantity of sugar can-
not he profitably extracted. A certain proportion of
the better qualities can be used for treacle and golden
syrup, but the manufacturer finds great difficulty in
dealing with the major portion. If, in the neighbour-
hood, rum or arrach manufacture is carried on, then
I he most profitable outlet is to sell the molasses for
the preparation of spirits.

The use of molasses as a fuel presents considerable
difficulties. If it is burnt mixed with the cane refuse,
at a comparatively low temperature, the charcoal
chokes the grate, whereas at high temperatures the
lime and other salts and the silica in the husks, form
a kind of glass, which blocks up the bars of the grate,
and prevents free access of air. In large factories
special furnaces are sometimes built. The molasses
are poured on an iron plate before the furnace, here
they dry, and arc then shovelled into the furnace. After
the fire is once lighted, it goes on without more fuel,
other than the dried molasses, and a fine ash, nearly
free from carbon, is obtained. The ash is very valuable
as a fertiliser, f>ecause it contains 35 per cent, of
pot;ish salts. It may also be used by glass-makers or
soap boilers. In fact, it often pavs to burn tlu-
molasses for the sake of its ash only.

It mast be borne in mind that the process of manu-
facture here described is only concerned with produc-
ing Dcmarara or brown sugar. TTie further refining
to obtain a fine, white, loaf sugar is a separate process
altogether, and is not generally carried out in the
neighbourhood of the sugar plantations. Large re-
fineries are to be found, for example, in Liverpool and
Greenock.

The m.-mufacture of sugar from the beet root will be
dealt with separately.

The diagrams, with the exception of Fig. i, have
been taken from " The Technology of Sugar," by
[. fi. Mackinlr)sh ; I'ig. 1 from " (icscliiihtc des
Zuckers," by Lippmann.

November, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

271

THE TOTAL ECLIPSE OF 1905.

A JOINT meeting of the Royal Society and the Royal
Astronomical Society was held on October ig to re-
ceive the reports on the observations of the recent
eclipse from the several parties sent out under the
auspices of these Societies.

The Astronomer-Royal gave a full account of the
doings of the expedition to Sfax, and exhibited some
fine photographs; Prof. N. L. Callendar narrated his
experiences in Spain, when a thick cloud entirely im-
peded observations; Mr. J. Evershed and Mr. H. F.
Newall also ga\e accounts of their observations, the
latter showing a series of interesting photographs; and,
finally, Prof. H. H. Turner told of what was done in
Kgvpt. On the whole, these reports may seem a little
disappointing, as nothing at all of a novel or specially
interesting character seems to have been observed or
recorded. Some faint oval patches or rings in the
corona just above the large prominence were noticed
by Sir W. Christie, who suggests they are the results
of a large and sudden explosion.

It seems a great pity that some of these fine photo-
graphs should not be published for the benefit of the
astronomically-inclined public, especially considering
that the costs of obtaining them were, to a large
extent, defrayed out of public funds.

The following accounts from observers in different
places should prove of interest.

At AlcaLlaL de CKisvert.

By Professor Marcel Move / Un'uerslty of Montpellier i.

I observed this magnificent eclipse at Alcala de Chis-
\ert, a little town on the oriental coast of Spain. I
venture to say I was favoured by the Spanish skies
The day before we experienced dull and wet weather,
and hope was almost gone ; but at night the clouds
broke away, and stars were glittering everywhere. At
sunrise, however, an ominous strip of clouds was hang-
ing on the south, and all the morning we watched them
on the horizon — a rather painful watch.

The first contact was seen in a perfectly pure sky,
but, some minutes after, two or three cumuli went from
Ihe west, and slowly made their way before the sun.
We were again almost in despair, but at the eventful
moment the clouds were far north ; totality displayed
its beauties without interference, except, at the end,
for a light, transparent vapour of which I shall say a
word later.

In order tO' secure good observations, I sketched for
myself a verv limited programme, and I had plenty of
time lo fill it without hurry. I intended to observe,
ist, shadow-bands ; 2nd, corona ; 3rd, general aspects
of the eclipse.

Shadcnv-bamis. — First as to shadow-bands. In the
eclipse of 1900, at Elche, I had a good view of this
phenomenon, and I was eager to see again these enig-
matic bands. Here are my results.

I saw shadow-bands three minutes before and three
minutes after totality, being unable to catch them

during the total phase. They were greyish bands, not
black, tolerably distinct and very wavy. Direction
from south-west to north-east, and motion perpendicu-
lar, namely, from north-west to south-cast, before and
after totality. I must add that the -wind — moderate —
was blowing from south-west, and clouds went from
west or west-north-west.

On the soil, white and smooth (the platform of the
• Vlcala .-itation), I had some rods with metric gradations.
I estimated the width of the bands at two inches, and
their distance apart at three or four inches. Their
motion was slow, difficult to count exactly, perhaps one

The Corona as seen at Alcala de Chis\ert, by Professor M. Moye.

or two inches per second. Vou will obtain a good illus-
tration of the shadow-bands by stretching a rope by
one end and making it waving with your hand by the
other end.

For the observation of the corona, I used a good
opera glass. I sketched carefully the coronal streamers,
and I had time enough to compare my drawing with
the eclipsed sun. The sun was encircled in a splendid
ring, very bright, almost dazzling, of a white, silver
hue, fading away softly in the darkness of the sky.
This inner corona was lengthened by .-m intricate system
of streamers, seeming as a whole an irregular star with
six or seven points. Two groups of prominences were

272

KNOWLEDGE & SCIENTIFIC NEWS.

[November, 1905.

evident, even to the naked eye, with a mag-nificent rosy
colour, the brijjhtest at the north-east part of the lunar
limb, the other at the south-west part, almost diametric-
ally opposite.

All the coronal rays were more or less of an ogival
outline, or " angel's wing-," as noticed in previous
eclipses. Their bases were broad, and they were taper-
ing and melting- away in an imperceptible mode. Three
of the streamers are worthy of special notice.

The north-east ray was exactly hanging over the
beautiful prominence seen at its root. It seemed as an
extension or, better, a sequence to the solar eruption.
I must add, however, that at the south-west part of the
lunar limb the second group of prominence was appar-
ently without influence on the coronal forms.

The north-west ray was very long, perhaps one and
a half lunar diameters. Curiously enough, its north
boundary was very sharp, even on the lunar limb, and
the inner corona was as rifted by a dark line and very
conspicuous.

As to the southern streamers, they went so far as two
lunar diameters (from the limb), and marked with cer-
tainty the greatest coronal activity. 'ITie eastern one
of these streamers seemed double, or formed by two
ogives overhanging.

The general appearance of the eclipse was, on a
whole, less interesting than in 1900. Brightness during
totality was surprisingly intense. I read without any
difficulty- small letterpress, and sketched my drawing
very easily. .All features of the land.scape were evident,
and the illumination perhaps greater than in 1900 — re-
corded as a bright one. With the exception of \'enus,
I was unable to see any star or planet. .Skv was grey,
not dark, rather a neutral tint, especially in the north,
with a yellow band on the south. Clouds remained un-
changed. On the landscape everything was greyish,
without reddish hue, the general appearance being very
sorrowful, and conveying some impression of ashe.s-
rain. I think the illumination, decidedly brighter than
that of a full nux>n night, was in relation with the great
activity of the solar envelopes.

TTie eclipse wind was very noticeable, coming to a
standstill .some minutes after totality. Tlie fall of tem-
perature (in the shade) was only 5° Fahr., but in the
height of atmosphere it must have been greater, for.
at totality, a thin vaporous veil (alluded to before) made
its appearance rf)und the rim. It was not a clf)ud, not
being visible before and after, and not moving, but
rather a condensation of the aqueous vapour by the
coolness of the shadow.

A last word. The corona of 1905 was brighter than m
1900, and especially active at the solar poles, a ty-pical
form of a maximum vear.

At CaLmpo de la. Isla, Burgos.

By C. NiELSE.s, F.R.A.S.

Corona. — As per sketch herewith; inner ring very
bright and about one-liflh lunar di;imetcr in width;
streamers faint and not extensive, longest about one
and one quarter lunar diameters in length; colour pinky
white. No vividness or sharp outline as at Ovar in
igoo; became visible on West limb three or four
seconds before totality.

Prominences. — Five large on Fvast limb of usual bright
cherry-red colour, except fourth from top which was

somewhat paler (several persons reported to me that
they had seen this and the chromosphere between 3rd
and 5th prominences of a cheniical green colour
( ? Coronium); possibility of complciiientarv colour or
colour-blindness eliminated by cross-examination); one
of these prominences persisted an exceptionally long
time before Ix'ing covered up by the advancing moon;
then two prominences in \orth-^^'est quadrant followed
two or three seconds later by an 8th in .South-West
quadrant, all of usual red colour, as was the chromo-
sphere spendidly visible all round West limb.

Body of Moiin appeared as disc — not as globe — of a
dull grey-black colour.

S/iadiw not seen coming on, but very distinctly in
drawing off over the distant 5,000 ft. high hills to ICast,
taking a minute or more to reach horizon.

Copy of Sketch made immediutcU after Totality on .lotli Auj^ust. 1005.

Colours of earth and sky round horizon ashen-grey,
then yellow to orange gold, round sun reddish-purple;
darkness much more pronounced than at Ovar, but
clouds spoiled these observations greatly; temperature
also changed little owing to same cause; wind westerly,
force 3, sky clouded, thoui^h totality from a few seconds
before to about one minute after was seen in a clear
patch of blue sky.

Bailey's Beads — seen by ine so clearly at Ovar —
though carefully looked for, were not seen, nor was
.Mercury visible at all; \eiuis shone brightly through
cloud openings several minutes before totality, and
Regulus ditto, but no other stars glimpsed, though
lof)ked for in their proper places, being all covered by
light clouds; returning light brighter than vanishing,
but clf>udiness also detracted from this ol)ser\alion.

Sliadowbands distinctly seen travelling from West to
Fast at rate of five to six miles an hour, distance be-
tween bands estimated at 30 to 40 cms., and width of
bands themselves 8 to 10 cms.

Effect on Animals. — No birds visible; donkey brayed,
sheep bleated, and cavalry horse galloped wildly about
when totality began.

November, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

273

At Vinaroz, Spa^irv.

By Father Augustin Morkord.

I had been staying for some days near Bordeaux. I
started for Spain from the Gare du Midi on Sunday
evening, August 27, at 6.42, and reached \'inaroz at
2.45 p.m. on Monday, after a much less difficult journey
than I had expected.

Father Cortie was at the station of Vinaroz. He
took me to the fonda (hotel), where I slept during my
stay, and to the house of Doctor Sebastian Roca, where
we took our meals in common. Our observation
ground was in a field of lucerne adjoining Dr. Roca's
garden. A gap had been made in the wall of separation
for our convenience.

Father Cortie had three instruments for photograph-
ing the spectra in different manners, and a camera, for
the corona, of about 20 feet focal length.

I, having brought the only telescope, a refractor of
4 5-i6ths in., and intending to make only visual ob-
servations, was appointed to give order to open and
close cameras at the beginning and before the close of
totality. My own observations were made with an
eyepiece x 70; field 52 ', with two crossed spider threads
di\iding the field into quadrants.

Wednesday began auspiciously. The sun shone and
the clouds were dissolved in the warm air, though
overhead at a great height some were thickening.

First contact was observed at 11.54. I' h-"' already
taken place a minute or two.

I watched several sunspots as they passed under the
black disc of the moon. They did not differ sensibly in
colour, observed with a prism and a green glass.

Now began our anxieties. A cone of cloud was
rising slowly from the S.W. At twenty minutes before
totality our chance of an untroubled view did not seem
great.

As I had to announce totality I paid great attention
to Rally's beads. This phenomenon differed consider-
ably from that of 1900. As then, I noticed the
abscission and subsequent disappearance of the terminal
portion of the southern part of the crescent. Mr.
Chambers has quoted in his Astronomy Halley's de-
scription of this in 171 5. A second time there was a
division, again at the south end, but less distinct. The
crescent fined down verv much. A little way from
either end it became narrower than at the ends them-
selves. They appeared almost lance-headed, slightly
diffused on the edges. The running together of the
beads was much less pronounced than in igoo. There
were two remaining at a slight distance from each
other — that to the south disappeared first.

I had been observing too closely during the last few
minutes to pay attention to the clouds, and I had seen
Baily's beads so distinctly that I never thought there
could be any. But I slipped off the green glass, and
it was evident something was wrong. The black disc
of the moon stood out forward. Behind there was a
bright but diffused light, which seemed to come from
behind the moon. But no coronal detail could be seen,
nor in the telescope did I see any the whole time.
However, I had no time to lose. The chief thing I
intended to do was to map down the positions of the
prominences, red, white, or pale tint, with coloured
chalks. Five splendid prominences were glowing
brilliantly in the N.E. quadrant. I had grey writing
paper with circles in pencil, divided into quadrants
corresponding with the wires in the eyepiece. I got
the positions of the prominences approximately correct.

but it was difiicult at first to say of what colour they
were. At first they seemed white, then I noticed a
faint tinge of red, as of vermilion much diluted with
Chinese white. When the chromosphere appeared it
could not be said to be red. The atmospheric condi-
tion evidently was answerable for this, and what I saw
were the usual hydrogen prominences. None were in
the least like the two shining white columns I saw at
Ovar in 1900. All were somewhat plum}', or cloudlike,
or arboreal in form. One of the latter shape had a
double trunk.

Long before these prominences in the N.E. were
covered by the moon's disc, one appeared floating with
no attachment, not more than 30°, if so much, from the
North Pole, in the N.W. quadrant. Others gradually
revealed themselves, till I had mapped seven; in both
quadrants 12. I saw none in the southern hemisphere.
All were pale, but very brilliant. Those in the N.W.
quadrant had, perhaps, a trifle more colour.

I found it useless to observe the corona with the
telescope, so I had several good looks with the naked
eye. Though there was a small thin cloud covering
the sun, the corona was most brilliantly visible through
it. It was not pearly or silvery white, nor was there
any trace of colour. The moon was the blackest of
blacks, and the corona the intensest of whites, and
very bright. The full moon at the meridian was not
comparable with it in tint or brilliancy. I thought of
our Lord's garments at the Transfiguration, " Candida
nimis velut nix."

The diameter seemed about half a solar diameter
broad. It was, of cour.se, impossible to see any faint
outlying parts. It appeared pretty equal in breadth all
round, the edge bordered with aigrettes. For the last
10 seconds it was free from clouds, but I saw nothing
to add to, or take from, what I have recorded.

I had to give the order to close cameras, so I watched
carefully for the orange-red glow of the chromosphere.
I saw no decided colour, but the western limb suddenly
became so bright that in some alarm I called out
"Close! " and in one second the sunlight appeared.
Totality had lasted 3 mins. 25 sees., as against 3 mins.
36 sees, calculated.

The sunlight gained with extraordinary rapidity, by
bounds, as it were, so that almost at once all im-
pression of eclipse was gone. Before long one felt the
sun beginning to scorch again in cloudless intervals.
The temperature had been agreeably cool for some
time before totality.

The darkness may be estimated by the following : —
The grey notepaper on which I drew had a fairly dark
circle in pencil, and cross lines about twice as broad
and dark. The latter were clearly visible, but the
former so little so that I found my red chalk marks
were some within and some without the circle.

I heard from others that they had seen the undulating
shadows. None of us had time to look for them.

There were no flowers and very few birds to observe.
The behaviour of the latter was distinctly abnormal, as
they were terrified by the discharge of bombs by a
well-meaning person who hoped thus to break or scatter
the clouds. This is commonly done (or attempted) in
the case of thunder clouds, which are low. But as
these bombs are loaded to burst at from 400 to 500
metres, and the clouds were enormously higher, their
effect, as might have been foreseen, was nil.

The houses, mostly flat topped, were crowded with
spectators, who applauded the eclipse so heartily that
my signals and Father Cortie's counting of seconds
were not too easily heard. As a spectacle, at least,
the eclipse was highly appreciated by them.

KNOWLEDGE & SCIENTIFIC NEWS.

[November, 1905.

Eclipse Shadow Bands.

During the recent total solar eclipse of August 30 there
appear to have been numerous satisfactory observations of the
shadow bands, and from the ver>' definite nature of many of
the reports now coming to hand, it appears very hopeful that
some advance towards the determination of their causation
may result. The following notes summarise some of the data
supplied : —

Constantiiu (Algeria). — M.M. Henri de la V'aulx and J.
Jaubert, observing at a station about 660 metres above sea
level, state that the bands were visible 20 seconds before and
after totality : although subject to various irregular move-
ments, it was found that on the hori;rontal plane their length
was in the general direction — N.E.-S.W. During the shorter
intervals of 7 seconds before and after totality a second series
of shadows were noticed intersecting the first series, always at
an angle of about 25". These had a width of 6 cm. or 7 cm.,
with intervening clear spaces of 60 cm. or 70 cm. The direc-
tion of motion of the bands was regular and definitely deter-
mined to be west-south before the eclipse, and in the opposite
direction after.

Tripoli {[iarhary). — M. Lucien Libert observed the bands on
a sheet of 25 square metres. They were first seen 6 minutes
before totality, and had the appearance of alternate bands of
light and shadow, displacing themselves in a direction per-
pendicular to their length. They were not absolutely sharp,
and at intervals appeared serpentine, as if affected by the
wind. The following summary is given of the directions of
the bands and their movements: —

h. m. s.

239
241 15

25'

Direction of Bands.

First series of Bands' N 60" E or S 60° W
Second ,, ,. ' N 80" E or S 80'' W

Third ,, ., N 45" E or S 45 ' W

S300E
S lo' E
S450E

S43<>W
S600VV

REVIEWS OF BOOKS.

J uolur Course of Practical Zoology, by the late H. M. Marshall and
C. H. Hurst ; 6lh edition, revised by F. W. Gamble (London :
Smith, Elder, and Co., 1905 ; pp. xxxiv. -|- 490, illustrated ;
price los. 6d.). — The mere fact oi a text-book having reached
its sixth edition affords such all-sufficient and convincing
evidence of its popularity and its fitness for its purpose that
any commendation on the part of a reviewer is a mere work of
supererogation. Nevertheless we cannot pass over the edition
which Dr. Gamble has in so many ways made superior to its
predecessors without adding one word of approval to this
excellent and invaluable little laboratory manual. In every
way it is admirably suited to the needs of the student ; a
feature in which it excels so many of its rivals being the
specially distinctive type, of various grades, in which the
different parts of the structure of each object described are
printed. By this arrangement the student is enabled to find
exactly what he wants at the moment without any vexatious
delay ; and although the arrangement of such details may
seem a trivial matter, yet it is one of which only experienced
teachers, like the lamented authors of the present work,
are able to recognise the full importance and value. Another
distmctive feature of the volume before us is the comparatively
limited number of the illustrations; and although this may at
first sight seem a disadvantage, it is in reality a great merit,
since it compels the student to resort to actual dissection, and
prevents him from frying to obtain his knowledge at second
hand by merely studying figures of the labours of others. The
only adverse comment we have to make in connection with a
work in every respect admirable, is that we regret the editor
did not see bis way to conform to modern usage by substitu-
ting the name Braiichwiloma for Amphiuxin.

Extinct Animals, by E. Kay Lankester (London : A. Constable
and Co., Ltd., 1905 ; pp. xxiii. + 331- illustrated ; price 7s. 6d.
net). — •• .\ book that tells you exactly what you want to know
about animals " was the comment made by a member of the
present writer's family after perusing a copy of this profusely
illustrated volume ; and as this tribute came spontaneously
from one of the " young people " to whom the author specially
appeals, it may be taken as satisfactory evidence that he has
hit the mark at which he aimed. Professor Lankester is
indeed justly famed for his power of imparting information
on abstruse subjects in a manner which, while thoroughly
accurate and often detailed, yet arouses the interest of his
hearers or readers to such a degree that, in place of tieing
wearied, they are left with :iu overwhelming desire to know
more about the subject under discussion. And as an example
of this excellent — and indeed only true — way of teaching, the
volume before irs, which is a revised report of a series of
lectures delivered by the author before a juvenile audience at
the Royal Institution during the Christmas holidays of 1903-4,
can hardly be excelled. Whether discoursing on the evolu-
tion of the elephant and the marvellous way iu which the jaws
of its ancestors were first lengthened to form a kind of
'■ bogus " trunk, and subsequently shortened when the real
article was developed, or discussing the strange fossil reptiles
of South Africa and Russia and their relation to .namiiials,
the author is equally succes.sful iu maintaining the interest of
his subject and carrying his readers with him. Hig animals
apparently have a special fascination for the learned professor,
and the reader is introduced in turn to the tliigh-bonc of the
mightiest reptile that ever ti'od this earth, to the fossil tooth
of a shark beside which the dental weapons of modern species
are mere playthings, and to the longest and heaviest elephant's
tusk ever put on the London market. Of course, a few holes
may be picked here and there by the captious critic ; and we
doubt not that in a second edition the author will remove
Dimdrodou from the Theromorpha (p. 212), while he will com-
pare the tail of an ichthyosaur with that of a shark instead of
that of "a fish" (p. 227), and will alter a certain sentence
(p. 94), which, to our mind at any rate, conveys the idea that
rhinoceroses possess trunks. Such little incidents detract,
however, iu no wise from the value and interest of a work
which only a man of unusually comprehensive mind and great
powers of generalisation could possibly have written, and
which will cert.iinly appeal to a much wider circle than the
young people for whom it is claimed to have been specially
written.

A Popular Introduction to Astronomy, by the Rev. A. C. Hen-
derson, B.D. (T. & J. Manson, Lerwick; 2s. 6d. net). — This
little book is exactly what its title implies. It is clearly and
popularly worded, and tells just what those who have not
made any study of the subject would mostly want to know.
And there is no waste of words ; almost every sentence con-
tains a fact worth recording, and the facts arc reliable.
The book is quite up to date, mentioning Jupiter's 6th and 7th
satellites. We can thoroughly recommend this concise little
guide to all who wish to gain a grasp of the great science of
Astronomy in .•111 hour or two.

A Technological and Scientific Dictionary. Edited by G. V.
Goodchildand C. F. Tweney (G. Newnes). Part X. (Pyr-San).
IS. each part. — A good explanatory collection of terms used in
science is much needed, and this work, which is gradually being
brought out in parts (and will be completed with the 13th),
should supply the want. The definitions here given are mostly
full and correct, and in some instances, such as under the
headings of " Pyrrole," " Radio-activity," " Railways," " Rub-
ber," and "Sanitation," articles of several columns are given.
But it seems a pity that the line is drawn where it is as regards
the classification of subjects to be included. Thus, though
such subjects as music, painting, and even heraldry are fully
treated of, mil i tary and naval sciences are not referred to ( Range-
finders, Rifles, Redoubts, Rockets, Sails and Sailing, <S:c.). We
find the dress of the ancient Roman soldier and inedia;val
armour described (Sagiiin,Saladc,&c.), but not the equipment
or armament of the warrior of today ; rapiers are defined,
but not rifles. Various other subjects, too, which might well
be included in the term " Technological and Scientific " are
not gone into. Several words, such as Uarc/iuliim (of air),
l<(/>uliioH (motor), and Riaumiir (ihermometer scale), are con-
spicuous by their absence. We must hope that a full appen-
dix will be added to include these omissions.

November, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

275

ASTR.ONOMICAL.

By Charles P. Butler, A.R.C Sc. (Loud ), F.R.P.S.
Variation of the Figure of the Sun.

In the early seventies Lewis M. Kutherfurd obtained a con-
siderable number of excellent photographs of the sun at his
private observatory, and these were later presented by him to
the Observatory of Columbia University, New York. As it
has been shown that stellar photographs taken by the same
astronomer are capable of giving results comparable with the
best heliometer determinations, Prof. C. L. Poor, of this
Observatory, has lately been induced to examine the old
solar photographs with the oliject of finding any evidence of
changes in the form of the solar disc.

In all there are ijij photographs, extending over the period
1S60-1S74, but part of these were only with a small lens.
Those taken from 1868-1874 were with his 13-inch telescope,
and of these plates 22 have been selected as suitable for
minute measurement, and on each the polar co-ordinates of
twenty-eight points round the limb have been determined.
Dividing these into two sets and taking means, it was possible
to obtain a most probable value for the polar radius, and for
the equatorial radius, of_ the solar disc on each plate. The
differences of these radii are tabulated in order of time, and it
is shown that there is a consistent agreement for the plates of
any one year, but that the plates of different years differ
radically. Thus the plates in 1S71 show the equatorial radius
to exceed the polar by some o"-^, while the plates of 1870 and
1S72, on the other hand, show the polar radius to be the greater
by about o"'2. A critical examination of the records shows that
the instrumental conditions, time of exposure, orientation, &c.,
were as nearly as possible constant, and it must therefore be
due to a real expansion and contraction of the sun's disc.

An interesting confirmation of these conclusions was then
furnished by a discussion of the heliometric measures of the
sun's diameter which were made by the German observers in
preparation for the transits of Venus in 1874 and 18S2. Pro-
fessor Poor has arranged all these solely with respect to time
of observation, and finds they readily fall into two series, one
from September, 1873-January, 1875, the other from May,
1880-June, 1883. In both of these groups it was found that
there was a progressive change, and that of the first group wa=;
in the same direction as that indicated by the Rutherfurd
plates, while the second group was opposite. Thus during the
interval from 1S81-18S3 the equatorial diimeter was apparently
growing longer in relation to the polar diameter, while during
the former period, 1S74-1875, the equatorial diameter was grow-
ing relatively shorter.

Again, photographs of the sun taken at Northfield, Minne-
sota, by H. C. Wilson, during 1893-181)4, indicatea shrinking of
the equatorial diameter with respect to the polar diameter.

On examining the epochs of these changes, it is at once
apparent that they have a distinct relationship to the curve of
sun-spot frequency, and on plotting the values there is good
agreement as far as the observations go.

These investigations seem to show, therefore, that the ratio
between the polar and equatorial radii of the sun is variable,
and that the period of this variability is the same as the sun-
spot period. The sun appears to be a vibrating body whose
equatorial diameter, on the average, exceeds the polar
diameter. At times, however, the polar diameter becomes
equal to and even greater than the equatorial — the sun thus
passing from an oblate to a prolate spheroid. It is possible
that in this variable figure of the sun may lie the explanation
of the anomalies in the motions of the planets Mercury, Venus,
and Mars.

Pola-risation Observations during the
Solar Eclipse, August 30th, 1905.

A \ ery interesting series of polariscopic determinations are
reported by M. Salet, who was appointed by the Paris Bureau
des Longitudes to observe the recent total solar eclipse at
Robertville in Algeria.

His first effort was the endeavour to detect any existence of
a magnetic field in the neighbourhood of the sun bv observing
if the plane of polarisation of the coronal light suffered any
deviation. This plane should, from reasons of symmetry, be
radial if no magnetic field existed in the gaseous atmosphere.
For these observations an equatorial telescope of 95 mm. aper-
ture was employed, furnished with cross wires and a Savart
polariscope placed before the eyepiece. This can be turned,
before the observation, so as to suppress the bands due to
terrestrial polarisation. During totality the bands were well
seen on the corona. The plane was found to be deviated in
the right hand direction by 2° S. The smallness of this indi-
cates that the sun has, in spite of its mass, only a slightly
magnetic field.

With another apparatus M. Salet was able to obtain good
photographs also of the coronal polarisation, showing fifteen
bands on the width of the solar diameter. They are visible
for about a diameter and a half from the solar liml), practically
up to the edge of the external corona. The polarisation had
a maximum intensity about 5' or 6' from the sun's limb, the
plane of polarisation being ahuost radial, and the slight devia-
tion measured visually was thus verified. A promuience
found crossing two bands apparently suffered no change of
intensity, showing without doubt the non-polarisation of the
prominence light. On none of the plates is there any trace of
atmospheric polarisation outside the corona or on the moon.

For comparison, several observations were made of atmo-
spheric polarisation by means of two Savart's directed go"
from the sun, but at this distance no bands were visible during
totality. At 30^ or 40° from the sun, however, the bands were
easily scan during totality. In the neighbourhood of the sun
the plane of polarisation was vertical.

A spectroscope was also provided with half its slit covered
by a nicol. The spectra obtained show different intensities on
the two halves by reason that on one the reflected solar light
is suppressed by the nicol. The coronal radiation, strong up
to 4 from the limb, is shown on both sides. Rays of hydrogen
and calcium are also shown, and others which will be measured
later.

CHEMICAL.

By C. AiNswoRTH Mitchell, B.A. (Oxon.), F.I.C.

The Chestnut Flour of Corsica.

The chestnut is the wheat of Corsica, and its flour is used
in the form of bread or polenta by the peasants throughout
the island. The chestnuts are slowly dried over a small wood
fire and stored until required for grinding. The mills are of
the simplest construction and consist of a wooden water
wheel whose axis turns a millstone which crushes the shelled
chestnuts against a fixed stone. The cheaper grades of flour
are of a dirty colour owing to the presence of particles of the
shells, and contain between II and 12 per cent, of moisture.
The composition of different varieties of the flour has been
determined recently by M. Comte, who finds that chestnut
flour closely approximates wheat flour in its food value. It
contains about the same amount of starch, more fat and cellu-
lose, but less nitrogenous substances (7 to 9 per cent., as
against 12 to 16 per cent, in wheat flour). Chestnut flour
attracts moisture very rapidly, and therefore soon becomes
mouldy unless kept in air-tight vessels. It has also the draw-
back of being very refractory to the action of yeast, and thus
producing an inferior kind of bread.

The Formation of Ozone by Ultra- Violet
Light.

It has been shown that the ultra-violet light emitted by an
electric mercury lamp produces violet colorations in glass
containing manganese which are otherwise only produced
very gradually by sunlight under normal conditions (" Know-
ledge AND Scientific News," this Vol., p. 158). The ultra-

276

KNOWLEDGE & SCIENTIFIC NEWS.

[November, 1905.

violet rays from the lamp have also a marked effect upon
oxygen according to the results of further experiments made
by Drs. Fischer and Braehmer. When pure oxyRen is con-
ducted through the lamp with precautions to keep the tem-
perature low, a considerable proportion of ozone is formed,
the yield increasing with the strength of the light up to a
certain point and then diminishing. If the temperature is too
high no ozone is produced, since that first formed is recon-
verted into oxygen. It is pointed out that these experiments
support Warburg's view that the formation of ozone notice-
able in silent electric discharges is due to the emission of
ultra-violet light.

GEOLOGICAL.

By Edw.\rd a. Martin, F.G.S.

The Age of the Earth.

Professor Sollas is always interesting', whether he is
reading a paper, and laying himself open to the criticism of
others, or whether he is criticising with sledge-hammer blows
a paper given by one of his geological colleagues. But he
takes criticism in good part, and it is well that he does, for he
has given every- opportunity for it in his " Age of the Karth "
(Fisher Unwin). He does not exactly say how long the
stratified deposits of the earth have taken in forming, but
leaving aside the possibility of radium and other radio-active
bodies acting in such a way as to upset all preconceived ideas
on the subject, he gives us the total of twenty-six millions of
years as the time which would have been necessary to deposit
all our sedimentary formations, at the assumed average rate of
accumulation of one foot in a centur)-. In asking, how far
does this period satisfy the demands of biology, although he is
aware that eminent biologists are not wanting who share his
opinion, he answers for himself. Amply. He might also have
added that there are many who c.innot share the opinion.

Thickness of the Earth's Sedimentary
Formations.

Incidentally, it is interesting to note the sum total of the
maximum thicknesses of the sedimentary deposits, so far as
Professor Sollas has been able to discover them. He gives a
total of 265,000 feet, or about fifty miles, at the base of which
are the great American pre-Cambrian formations, Htironian,
18,000 feet ; Penokee, 14,000 feet ; Keweenawan, 50,000 feet ;
although there seems to be some doubt as to the thickness of
the last-mentioned. It will be necessary for our text-book
writers in future to have a care not to repeat the oft-quoted
thickness of about a dozen miles of sedimentary rocks.

The Sun ais a Non-Luminous Star.

Sollas quotes Kelvin's argument that the life of the sun as a
luminous star is even more briefly limited than that of our
oceans. This means that if the age of the sedimentary rocks
is as already given, our oceans may have been formed fifty-
five millions of years ago, and that after a short existence
almost as boiling water, they grew colder and colder, till they
became covered with thick ice. So the earth may have re-
mained, frozen and dark, until in obedience to the growing
splendour of the sun, the long night of the earth became
bani.shcd, and the commencement of rtmning wafers was the
beginning of the formation of the sedimentary rocks. Just one
suggestion here. Is it altogether inconceivable that life may
have existed in the heated waters of the earth in the days
of the non-luminous sun ?

The Radium "Apparition."

Professor Sollas speaks pictMres(|Mely of a now cause of dis-
tarbance, which looms up before us, " vague and gigantic,
threatening to destroy all faith in hitherto ascertained results,
and to shatter the fabric of reasf)ning raised upon them."
This appantion is radium. If the earth posses.ses radium
throughout its mass to the extent of one five-millionth of
a gram per cubic me'.re, it has been asserted that the whole
of the heat lost by radiation into outer space would be com-
pensated for, and the temperature gradient would be un-
changed for a very- long period. So the geologist breathes
freely again, and blesses the apparition.

Fossil Trees in Victoria Park, Glasgo>v.

Glasgow is fortunate in possessing, in its \'ictoria Park, the
remains of an old carboniferous iMndsurface, which when laid
bare showed a number of petrified broken trunks and roots of

Fussil Tree Trunk i5iglllarla), Qlasgo'

Sigillaria. These have wisely been protected, and by the
erection of a commodious shed over them, have been pre-
served from the effects of the weather. We reproduce some
photographs of them. We know of no object-lesson so hkely to

Fossil Tree Trunk (Sigillaria), Glasgow.

arouse interest in the study of geology as that presented by these
easily-accessible specimens of a by-gone age. We plead for a
better use of such specimens, and for a more general adoption
of the study of geology in our Polytechnics.

OR.NITHOLOGICAL.

By W. P. PvcKAiT, A.L.S., I".Z.S., M.I5.0.U., &c.
Bee-ea-ters in Yorkshire.

The Zoolot;isl for CJctober reports the occurrence of three
Bee-eaters at Bentham, ^'orkshire, during the middle of Sep-
tember. They had halted by the way in a garden, where they
discovered a promising supply of food in the occup.ints of a
number of beehives. On one of th(- nunil)cr, an adult male,
being shot, however, the rest appi-ar to have moved off to
safer quarters.

Hoopoe in Sussex.

Mr. J. S. Snelgrovc writes to the I'uUI, October 7, to say
that he saw a Hoopoe on September zf> at Kotherfield, Sussex.
The bird was sitting in a cart rut, but rose (luickly and flew
out of sight behind some trees. Doubtless we shall soon hear
that it has been shot.

November, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

277

Common Quail in Ireland.

Mr. Allan Ellison gives a short account in the Zoolo'^ht for
October of the re-appearance in some nnmbersof the Common
Quail (Coturnix communis) in Enniscorthy,Co. Wexford, during
July last. This note is of interest, inasmuch as for the past
few years this bird has been rather scarce in Ireland.

Solita.ry Snipe-
Mr. .\. R. Brooke writes to the Fidd, October 14, to record
the fact that a Solitary Snipe was shot on October 6 in Pem-
brokeshire, but no particulars as to sex or weight are given.

An adult Great Snipe weighing 6 ozs. was shot at Snettisham
during the last week in September- The average weight for
this bird, we might remark, is about 75 ozs.

We learn from the Field. September 30, that a Solitary Snipe
was shot " lately " in the middle of Ackergill Moor, near Wick.
The age. weight, and sex of this specimen are not stated.

GreenlaLnd Falcons in Ireland.

The Irish Saturalist for October contains a note by Mr.
H. J. Moran on the shooting of no less than eight examples of
he Greenland Falcon on the West Coast of Ireland during
this summer. Near BelmuUet two females and an immature
male were shot, while three others were seen of which one was
trapped but escaped. At the Great Skellig an adult male and
an adult and immature female were shot ; at Crossmoline,
Co. Mayo, another, sex not stated, was shot, while a young
female was killed in Co. Cork. Expressions of regret for this
slaughter are in vain.

Icela.nd Fa-lcon in Co. Galwa-y.

An immature female of this species was exhibited at the
Dublin Naturalists' Field Club in March last, which was shot
in Oughterard, Co. Galway.

Honey Buzza.rd in Norfolk.

The Field, October 7, records the fact that a Honey Buzzard
was shot at Snettisham, in Norfolk, " recently." The bird was
an immature specimen, and was killed in the act of rifling a
wasp's nest.

Ma.nx-Shearwater.

Mr. A. H. Patterson records in the Zooloe;ist for October
the finding of a Manx- Shearwater on the beach at Great Yar-
mouth, which appeared to have been dead some four days.

In the same journal is a record of the Manx-Shearwater in
Worcestershire, one having been shot on a small piece of water
near Bromsgrove on September 16.

PHYSICAL.

By Alfred \V. Porter, B.Sc.

R-egulat-rities in Spectra..

A NOTABLE advance has been made by Dr. Halm (Lecturer in
Astronomy in the University of Edinburgh) in connection with
the structure of spectra. Hitherto special formui:E have been
needed in special cases to represent the series of lines which
occur in spectra. Thus, for the lines on a " band " spectrum,
Deslandres has used the formula n = Uj, + am- where n,, is the
frequency of the first line (the head of the band) and m is any
integer ; while, for line spectra, Kayser uses either the formula
n = a + bm-'- + cm—* or similar expansions, and Rydberg

the approximate formula n = a -I where a, b, and c

(m + c)^
are constants and m is any integer. The different type of
equation necessary for line or band spectra respectively
seemed to indicate that these kinds of spectra were funda-
mentally different from one another. Dr. Halm has now shown
that a single type of equation is sufficient for representing all
spectra, and that it represents them much better than those
previously used. This equation is

— -i — = a (m + c)- + b
In — n

where N, a, b, and c are constants and (as before) m is any
integer. When b is zero this equation is identical with Ryd-
berg's ; on the other hand when c is zero and b is very large

compared with a, it approximates to Deslandres'. Curiously
enough a formula, of which this is merely a mathematical
modification, had already been employed by Thiele for band
spectra ; but he rejected it as inadequate. Halm shows that
this rejection was unwarrantable and resulted simply from
Thiele wishing the formula to do more than was necessary.
In Dr. Halm's paper most known series are carefully worked
out and adequately represented. For many cases the con-
stant c is zero (it is so for ig series out of 44). All the first
subsidiary series (except Mg, Ca, Sr) belong to this group. In
other cases c is usually a simple fraction, such as y-^. The
occurrence of these groups shows that remarkable relations
must exist between series of lines belonging to different
elements, but of the same group. For example let n^ be the
frequency of the xth line of a series, and n^' that of the same
line in any other series beloiif^ing to the same group ; then if
n and n' are any other corresponding lines in the same two
series and e is a constant

- — i , = constant.

nj - n n^' - n'

Hence if nx, n^'^ and the constants be known the whole of the
second series can be calculated from the first. In this way
Dr. Halm calculates eleven lines in the third subordinate
series of Helium from the well-known Hydrogen series, for
both of which c is zero. An interesting geometrical relation
can also be exhibited. If we mark upon a straight line, on any
arbitrary scale, the lines of a given series in such a way that
the distances between two lines express the differences of the
corresponding frequencies, and if from any point outside we
draw straight paths through the points so selected, then the
lines of any other series belonging to the same c-group can be
represented as the points of intersection of those straight paths
with a certain transversal line.

The following diagram will illustrate this theorem : —

On the base line the dots show the relative positions of the
hydrogen lines corresponding to m = 3, 4, 5 . . .00. From
an arbitrary point O lines are drawn to these dots. The re-
maining lines have then been placed so that their points of
intersection with the radial lines give correctly, on the same
scale, the frequencies of the lines in one series for each of the
following substances : — Lithium, Helium, Thallium, Zinc, and
Indium. .\11 spectra of the same group thus drawn would ap-
pear to coalesce if viewed from the point O.

In order to show that the formula is as valid for band as for
line spectra, Dr. Halm calculates the wave lengths of the
first triplet series in the line spectrum of Oxygen from the
wave lengths of lines in the Cyanogen band spectrum ! ! The
question of the regularities in spectra is obviously placed on a
fresh footing.

Dr. Halm's paper appeared in the Roy. Soc. Edinh. Trans-
actions, July, 1905.

[Since writing the above abstract I have discovered that this
formula has previously been discussed by Professor Fowler, of the
Royal CoUegeof Science, in T/(C/!sfi-o/'/y's/irii//oHC«n; for 1903. He
shows there that it is the most satisfactory formula for line-spectra.
He also applied it inThe A5troph}iskaljonriial{or ]anuary, iga^, to
the new triplets in the arc-spectrum of strontium which were
discovered by him. He therefore has the credit of having antici-
pated Dr. Halm so far as line-spectra are concerned. He does
not appear, however, to have applied it to band-spectra.]

278

KNOWLEDGE & SCIENTIFIC NEWS

[November, 1905,

ZOOLOGICAL.

By R. Lydekker.
The Connecticut Footprints.

Dr. R. S. LiLL. of the AijriciiUura! College at Amherst, in
Massachusetts, has recently been devoting attention to the
wonderful tracks of fossil animals in the sandstone strata of
the Triassic strata of the Connecticut Valley, which have been
known to the inhabitants for well nigh a centurj', and were
described many years ago by the late Professor Hitchcock,
President of Amherst College, who believed most of them to
have been made by birds. Owing to the porous nature of the
sandstone, very few of the bones of the ancient creatures
which formed these tracks have hitherto been discovered,
and for a long time indeed, none were known. The few
skeletons that have been found indicate, however, that these
tracks, as was to be expected, were made by dinosaurian
and kindred reptiles, some of which walked on their hind legs
alone, while others went on all four. One of these bipeds
was a large carnivorous species, which left three-toed tracks
of one type. Another dinosaur, of herbivorous habits, has
also left footprints which are in most cases not very dis- !
similar to those of its carnivorous relative; but in places \v<
find indications that the creature sat down, resting its tail
and small five-toed front feet on the ground; thus provin,;
that some at least of the four-footed tracks were made by
animals which were normally biped. One type of four-footed
tracks has, however, been proved to have been made by a
reptile very similar to a crocodile in structure, but with the bod >
carried high above the ground on long stilted mammal-lik(
limbs. For this creature the name of Slixox'tis longipcs has hwu
proposed, but it ought surely to bear the title Batraclut[u
grucilis, bestowed long previously on its tracks.

British Dinosaurs.

In the July number of the Oto!of;iciil .\tcii;a:i)ie Baron Francis
Nopcsa continues his restorations of liritish dinosaniian
reptiles, dealing in this instance with the remains of a lai ,<
carnivorous species from the Oxford Clay preserved in aprisai.
collection at Oxford itself. By most palaeontologists these i ■
mains would be referred to the well-known f^enus Megatosaw :
Baron Nopcsa identifies them, however, with a reptile repi'
seated by a few bones in the Paris Museum, described und. i
the name o{Slriplosponclytiis ciivieri. :ind states that thiscreat 1:1 ■
is distinguished from Mrgalosaiinis by having four, in place ■ t
only three, toes to the hind feet. We await with interest thr
comments of Baron Nopcsa's fellow-workers.

BlaLck Leopards.

Black leopards, like black jaguars and black pumas, arc ii' .t
a species of themselves, but merely a dark phase of the onii
nary spotted leopard. It is, however, interesting to kavn
from India that the former animals, so far as the evideu' ■
from a single instance goes, when mated with individual>
their own kind breed true, although when crossed with ilr
spotted race the offspring may be of either type. In tlx- i:.
stance referred to two litters of wholly black cubs were jm
duced by a pair of these dark leopards.

A C\jrio\JS Sqxiirrel.

A remarkably coloured new species of squirrel has recei '
been de.scribed from Upper Burma, under the name of Sc
haringloni. Unlike any other known member of the gr-
this species is of a pale creamy buff colour above, witti
tail whitish and the under-parts buffish. As two specii
were obtained, it is unlikely that we have to do with an al
form; and an adef|iiat(- explanation for this di^parturc li' 1
the normal typ'- of squirrel < oloration is therefore required.

The Indian Palm-Squirrel.

Everyone who has visited India is familiar with the pf i'
little striped palm-squirrel, which is to a considerable <xl' : ■
a partially domesticated animal, or. rather, an animal «li
has taken to quarter itself in the immediate neighbourln !
of human habitations. Hitherto it has been generally 1;
posed that there is only one palm-squirrel throughout Ind
It has been recently shown, however, that there are really 1
distinct types, each with local modifications. The first i
typical palm-,squirrel, Sciim/s (I'linamhiiliisj palmarum, inhabits
Madras, has but three light stripes on the back, and shows a

rufous band on the under-side of the base of the tail. In
Pennant's palm-squirrel, S. (F.) f>eiiiiiiiiti, on the other hand,
there is a pair of joint addition.il lateral white stripes, making
five in all, and the under surface of the tail is uniformly
whitish olive. .\s this species has been obtained in Sural and
the Punjab it is believed to be the northern type.

New Africatn Antelopes.

A well-known German naturalist has rocentlv described no
less than twelve antelopes from East Africa as new ; many
being ranked as species and a few as sub-species, although
we should be disposed to relegate the majority to the latter
grade. Perhaps the most interesting feature in the communi-
cation in question is the naming of a new gouus (Kliyitcho-
tragiis) for those curious representatives of the tiny little ante-
lopes commonly known as dik-diks in which the muzzle is
produced into a kind of miniature trunk ; Madoqua tiuentheri
being the typical representative of this sub-group.

November Meteors.

4S- -

which may be expected ahoul i;-i.5 Nov., showinu the riiilinnt pninl
ThU Region l> near the Zenith about 9 to 10 o'clock on those dote».

November, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

279

Photography.

Pure and Applied.

By Chapman Jones, F.I.C, F.C.S., &c,

Pinaiype. —This is the latest method of three-colour
photography, the instructions and materials for which
are issued by the colour works, formerly Meister,
Lucius, and Briininp. Messrs. Fuerst Bros., of Phil-
pot Lane, are the English agents. The method is, I
believe, intended for the use of amateurs and those
who make their own prints rather than for commercial
work. The ordinary three negatives are made through
a blue, green, and red colour-screen respectively. From
each of these a transparency is made either by super-
position or by common enlarging methods, and each
transparency in turn furnishes a " print plate " by
exposing beneath it a plate coated with gelatine and
rendered sensitive by means of potassium bichromate.
After due exposure the " print-plates " are washed,
and, with or without drying, each is placed in a solution
of the appropriate dye. The colouring matter is not
absorbed where the gelatine has been completely
hardened by the exposure, but it is taken up in the
other parts, most copiously where there has been least
exposure under the positive. The final print is pre-
pared by squeegeeing a piece of " transfer paper "
(gelatine coated) on to each " print-plate " in turn,
with due regard to register, condition of moistness, and
time that it is allowed to remain on the "print-plate," so
that the amount of each dye absorbed by the " transfer
paper " may be duly proportioned. The " print-
plates " can be used as often as desired, preferably
soaking them for a few minutes, each in its proper dye,
solution, for each final impression. The resulting
prints are finally placed for a minute or two in a solu-
tion, the formula of which is not stated, " to increase
the pictures' fastness to light " and harden the gela-
tine, washed for about five minutes, and hung up to
dry. The method is also applicable to the preparation
of coloured transparencies.

T/ie Royal Fhotographic Society's Exhibition. — As the
Exhibition will be closed before this journal is pub-
lished, my notes on it must be purely retrospective.
It is vcrv satisfactory to find that the practice of record-
ing changes by photography is increasing. Not merely
recording the phases of rapid motion, as in a series of
photographs of a splash, but slower movements, as in
the skin moult of a caterpillar, the germination of a
prass seed, and the difference caused in an oak tree by
fifty years of life. A mere photograph of a living
creature is now common-place, unless the animal is
rare; to secure attention some characteristic act or
attitude must be shown, such as a flock of gulls alight-
ing on the water, a robin eating a worm, or swans
flving in anger at their assailant. A set of sixty
lantern slides of mediaeval baptismal fonts was medalled
by the judges, because such work shows considerable
sacrifice in the attainment of a specific object, and an
object worthy of the sacrifice. A set of lantern slides
should always have a definite aim, and if the aim is not
obvious it should be stated by the exhibitor. The
" pinatype " method of colour photography was demon-
strated at the Exhibition.

Paper as used iti Photography.— Vor certain photo-

graphic purposes, as in printing processes where the
sensitive substance comes into immediate contact with
the paper, and is, in a measure, absorbed by it, as in
platinum and albumenised silver paper, it is necessary
to have paper prepared with great care from pure
materials. But when the sensitive material is prepared
as an emulsion and applied so as to form a distinct
layer, as in the usual printing out papers (P. O. P.), it
is desirable to have a srnoother and less absorbent sur-
face than that of simple paper. For such purposes the
paper receives a preliminary coating or enamelling, as
of gelatine hardened with chrome alum, and coloured
with a pigment, such as madder lake, or whitened and
made more opaque by a white pigment, such as barium
sulphate. But in order to get the most perfect im-
pressions from half-tone typographic blocks with their
minute and, therefore, shallow etched dots, a still more
perfect surface is necessary, and this has led to the
introduction of " art papers." From a communication
made by Mr. R. W. Sindall to the Society of Chemical
Industry and the discussion that followed it, we learn
that " art papers " are coated on both sides with some
inert mineral substance, such as china clay, barium
sulphate and alumina, slaked lime and alum, or pre-
cipitated calcium sulphate, which is mixed with a
sufficient quantity of an adhesive, such as glue or
casein, to hold it together during the printing process
without offering a too little absorbent surface to the
ink. A coloured pigment is added if desired. Casein is
largely used, and as it is insoluble in water, borax or
ammonia is added with it to dissolve it, and a little
formaline may be added also to get rid of any smell due
to incipient decomposition. A heavy " art paper "
may contain about 35 per cent, of mineral matter, and
the thickness of the original will be increased by some
12 to 15 per cent, by the coatings.

A pure paper must present a very uneven surface, be-
cause of the irregularly overlaying fibres. The addi-
tion to the pulp of from 5 to 10 per cent, of mineral
matter gives a rather smoother surface, and twice this
amount gives a marked improvement. A so-called
" imitation art paper " is better still and may contain
30 per cent, of mineral matter, though it is not applied
as separate coatings as in the best " art papers," but
put into the pulp, and brought to the surface to a
certain extent by moistening the paper just before it is
drawn through the rolls of the calender.

I suppose that an impression in black printer's ink
is one of the most permanent kinds of record that can
be imagined, but obviously its life is limited by the
durability of the substance that it rests on. No doubt
there is a tendency to consider that when the paper
proper is to be sandwiched between two surfacing
layers, it is not necessary to pay very much attention to
its quality. But however this mav be, it is certain that
from a chemical and often from a physical point of
view every increase in complexity means an added
possibility of disintegration or decomposition. Gela-
tine (or glue) and casein are particularly susceptible to
damp. In " art papers " the impression does not lie
on paper at all but upon the surface of the coating.
The preparation of a paper that shall satisfy the de-
mands of the printer and at the same time be free from
suspicion when regarded from its chemical and physi-
cal aspects, remains a very difficult if not an unsolved
problem, but it is well to know how we really stand in
this matter, that we may not regard only the permanent
character of the impressions of our " reproduced "
photographs, but also the resisting power to adverse
influences of the material on which they are made.

28o

KNOWLEDGE & SCIENTIFIC NEWS.

November, 1905.

Conducted by F. Shillington Scales, f.r.m.s.
Elementary Photo-micrography.

] H.WK bcx-n frequently ;i>ke(l to _<;i\e some information
on photo-micrography which would assist absolute be-
ginners. In endeavouring to act upon the suggestion
it must be understood that these notes make no at-
tempt to instruct those who are already more or less
expert; absolute ignorance of the whole matter is
assumed as a basis. For this reason, also, my remarks
will deal with the mere elements of the subject only.

The first question that is invariably asked is whether
a regular photo-micrographic camera is necessary. I
am afraid that the answer must he in the aflirmative.
The main reason for this is that absolute rigidity and
absence of movement is a sine qua non. An ordinary
photographic camera could doubtless be fitted to aii
efficient baseboard by anyone with a mechanical turn,
or who is used to carpentry, but the adjustments would
be less satisfactory than in a camera made and designed
specially for the purpose, whilst the cost of making
such a baseboard and adding the necessarv fittings and
connections would go some way towards the cost of a
proper camera. A further reason is that the ordinary
camera has insufficient bellows extension. A modern
photo-micrographic camera extends to at least thirty
inches, and often to very much more. Of course, I
have seen photographs taken with an ordinary camera,
supported at the necessary height by books of the
requisite thickness, but though they seemed to plea.se
their authors I am afraid they would not bear ordinary
criticism.

The next question is as to the respective advantages
of a horizontal and a vertical camera. Dr. Henri Van
Heurck, the well-known diatomist, has done nearly all
his work with a vertical camera, and there is much to
be said in its favour. It is convenient to use; the
micro.scopc is in the upright position to which the
observer is accustomed, and the adjustments of the
microscope are thus more familiar to him, especially
because he continues to use the mirror to reflect the
light; it is easy to draw the camera-bellows up out of the
wav, to make most of the adjustments in the ordinary
manner, and then to make the final connections,
whilst if the camera is of the box type with a large
door through which the head can be put to look down
the microscope tube the matter is simpler still. More-
over, there are certain cases, such as those in which
the object is but temporarily mounted, sav, in water or
otherwi.se, in which the microscope must be kept up-
right. But I think there can Ix; no doubt that the
horizontal camera is mf)re satisfactory for all-round
work, and, as a result, it is generally used and pre-
ferred. Its .solid base gives complete rigidity, with, at
the same time, every facility for long extension, and it
lends itself in particular to the adjustment of illuminant
and microscope with their intervening accessories, and
more especially to the newer arrangement of optical
bench, which has done .so much to simplify and co-
ordinate the necessary optical adjustments.

I do not propose to speak here of the more elaborate
forms of photo-micrographic camera. I am writing
for beginners, and, therefore, the simplest camera is
the best for them. It must have a solid and steady
base, and nicely turned legs must be conspicuous by
(heir absence. The part of the base which supports
the microscope must be long enough to hold not only
the microscope, but the lamp or other illuminant, and
there must be room between the two for condenser,
cooling-trough, and stand for coloured screens. All
these should Ix; arranged on stands running be-
tween parallel guides so as to maintain their align-
ment with the optic axis of the microscope, whether
they are brought forward or pushed back; the stands
should be square and not round for the same reason,
and there must Ijc means by adjustable bars and by
centring screws or otherwise of making the vertical
and horizontal adjustments, which will be found to be
necessary for each piece of apparatus, and which will
prove an important factor in the results. The advan-
tage of the optical bench is now c\ident. In its
simplest form this is merely a heavy triangular iron
bar, carefully planed, screwed to the baseboard of the
camera, and carrying the light and optical accessories
on saddle-shaped Ijases on its edge. As I have already
said, this simplifies matters marvellously, cncc the
primary adjiisimatts arc made, but a couple of parallel
wooden guides make a quite efficient if less convenient
substitute.

The camera itself will be raised a few inches higher
than the rest of the baseboard, so as to bring its centre
level with the centre of the microscope tube. It should
extend to at least thirty inches, w-hilst many extend to
sixty inches. The fittings of the camera will be de-
scribed in due course; here I may just say that the
light-tight joint may be nothing more elaborate than a
loose sleeve of black velvet attached to the camera
front and slipped over the microscope tube and held
there in place by a rubber band or ring of elastic. A
shutter must, of course, be provided.

The camera and baseboard must all be made of care-
fullv-seasoncd mahogany, and the camera must run
smoothly and truely in its slides. The dark-slides, &c.,
should be constructed to take half-plate slides, and
should have carriers to take quarter-plate slides as well.
I need scarcely say that it is absolutely essential that
the plates and the focussing screens must all lie at
exactly the same distance from the microscope.

A camera of this sort can lie obtained from all the
leading opticians from jQ^ upwards, ruid I)oth R. iV J.
Heck, and W. Watson and .Sons make, in addition, the
optical benches to which I have referred.

Let us now deal with the illuminant. Lamp-light —
the light of an ordinary half-inch parairin microscope
lamp — is quite satisfactory for all but the most critical
high-power work, but, of course, it needs :i relatively
long exposure. An inch lamp is better. The incan-
descent burner is not satisfactory — it gives a good
light, but it is spread over too large a surface, and if it
is focussed it gives an image of the texture of the
mantle. Acetylene is really excellent, the light is
good, it is small, and it has high actinic properties.
The incandescent electric light is unsatisfactory, be-
cause the filament is too obtrusive; the electric arc-
lamp is best of all, but, of course, can be indulged in by
few who have not the rim of a laboratory, and so for
all-round work the oxy-hydrogen jet is th(! best for
private workers. It is strong enough, and has sufficient
actinic value to make the exposure as short as one need
rca.sonably wish it to be.

t To he continued, j

November, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

281

The " Ashe-Finlayson " Comparascope.

This instrument is the joint invention ot Messrs.
Ashe and Finlayson, and its object is to enable an ob-
server to make an exact comparison of two different
objects by showing them simultaneously in the same
microscope field. The principle is quite simple. What
is practically a second microscope is placed horizontally
and at right angles to the optic axis of the microscope
proper. This second microscope in its simplest form
is a horizontal bar, carrying at one end an objective, and
at the other end a mirror with universal movements,
whilst between the two is a clip serving as a stage and
moving by rack and pinion, the position of the objec-
tive itself being necessarily fixed. Between the nose-
piece and objective of the microscope itself is screwed
a tube about an inch long, with a hole at one side to
which the auxiliary horizontal apparatus is attached.
Inside this aperture is fixed a reflector of tinted glass,
worked to a perfect plane on its upper surface, and
placed at an angle of 45° to the microscope axis so as
to reflect the secondary image upwards to the eye-
piece. But in order to allow free passage of the light
from the primary objective this reflector does not pro-
ject more than half-way into the tube. Further, to
prevent the overlapping and confusion of images, each
set of rays is confined to its own side of the field of
view by a removable division plate, which extends from
the short tube containing the reflector to within an inch
or so of the ocular, the tube being thus divided into
semi-cylindrical sections, each of which transmits rays
from a different object, and the image of which occu-
pies different segments of the field of view. The in-
ventors have also used a prism instead of the reflector,
but have found the latter to be equally efficacious and
more simple. The apparatus is made by Messrs. R.
and J. Beck, Ltd., of Cornhill. It is quite simple to
use.

Watson's BoLctil Microscope.

Last month I called attention to a new microscope
by Messrs. W. Watson and Sons, which, whilst con-
forming outwardly and in appearance to the Continental
model, retained many of the principles which dis-
tinguish the English stand, more especially the lesser
fine adjustment. An elaborated form of this micro-
scope, which is to be known as the " Bactil," possesses

one or two additional features that are worth a further
note. A mechanical stage can be made either detach-
able or as an integral part of the stand. In the former
case it is ver\' liable to deteriorate in its working parts
and to fail in rigidity, and in the latter case it suffers
when rough work is being done. In the " Bactil "

microscope the horizontal movement works above the
stage and is attached to it by thumb-screws so as to
be removable, whilst the vertical movement is fixed
below the stage, out of harm's way, and is non-re-
movable. Incidentally the long range of movement of
the detachable form of mechanical stage is thus
attained. The other noticeable feature in this micro-
scope is the fitting, when required, of a coned con-
denser, carrying the iris diaphragm, which can be
readily turned down out of the optic axis if necessary.
The arrangement is very similar to that already seen on
some Continental stands, notably one of Zeiss', and
was first introduced, I believe, on an English stand by
Messrs. Ross. The subsidiary iris diaphragm im-
mediately beneath the stage always seems to me, how-
ever, somewhat unnecessary.

Notes and Queries.

Major E. F. Bcccher, Chcltaiham. — I shall be very glad to
give you any assistance in my power, but I am afraid I cannot
advise you unless I know more definitely the nature of the
investigations you wish to make. Histological methods vary
greatly according to the end in view, and a fixing or staining
agent that would serve one purpose might be quite useless for
another. If you will let me know exactly what investigations
you wish to carry out, I will iry and make some suggestions as
to how to set about them.

H. Cliff, Stafford. — The best book dealing with vegetable
parasites is Tubeuf s '■ Diseases of Plants," translated by
W. G. Smith, and published by Longmans in 1S97. A very
elementary and simple little book is M.C. Cooke's " Rust, Smut,
Mildew, and Mould ; an Introduction to the Study of Micro-
scopic Fungi," published by \V. H. Allen and Co., but I am
not sure whether this is not now out of print. Second-hand
copies are quite easily met with, however, and would not cost
more than a few shillings. With regard to insect parasites on
plants, you might get Miss Ormerod's " Manual of Injurious
Insects." I am afraid none of these will give you much infor-
mation as to preparing objects for the microscope, but I shall
be glad to help you so far as I am able if you get into any
difficulty.

A. H. Ghiistcr, Darlington. — As far as my inquiries go, it
seems very improbable that MeniUus Uicrynians forms resting-
spores of any kind, and indeed it would be contrary to any-
thing that has hitherto been observed with regard to the whole
group to which this fungus belongs. The specimens you sent
were not sufficient to pronounce an opinion ; but it seems
doubtful whether the fungus you have been examining is really
Muriiliiis. Under any circumstances the conditions under
which you have made the cultivation have vitiated any trust-
worthy results, as your observing •' swarm-spores " (which
might be mycomycetes or infusoria !) shows the culture to
be contaminated. I think, therefore, it may be assumed that
the spores which you have observed are really those of some
other fungus. I am glad you succeeded in resolving ampki-
pleura pdlucida with oblique illumination, but if mounted in a
medium of sufficiently high refractive index it ought to be
resolvable with axial illumination with an immersion lens of
i'25 N.A. The condenser should be carefully centred, the
edge of the lamp flame focussed rigidly upon the diatom, and
then the condenser should be racked up the merest trifle
within its focus.

A. RoK'land, Newport. — There is an excellent book on Chiro-
nonius, by Miall and Hammond, published by the Clarendon
Press, in 1900, which is a model of what such a book should be
and gives explanations as to methods. With regard to the
general structure of Bees you had better refer to Dr. Sharp's
volume on •' Insects," part ii., in the Cambridge Natural
History. I am glad you found the note en glycerine mounting
helpful. I do not think caoutchouc cement would be satis-
factory for glycerine mounts.

[C^ommunicatwns and Enquiries on Microscopiail ni.ilters should be
addressed to F. Shillington Scales, "Jersey," St. Barnabas Roal,
Cambridge.]

282

KNOWLEDGE ^: SCIENTIFIC NEWS.

[November, 1905.

The Face of the Sky for
November.

By W. Shackleton, F.R..A.S.

The Sun. — On the ist the Sun rises at 6.55 and sets at
4.33 ; on the 30th he rises at 7.44 and sets at 3.53.

The equation of time is a maximum on the third, the
Sun being i6m. 20s. before the clock.

Sunspots and prominences are numerous ; at the time
of writing several fine groups of spots are visible on the
solar disc.

The following table gives the position, angle of the
Sun's axis, and the heliographic latitude of the centre of
the Sun's disc : —

Date.

Axis inclined from N.
point.

Centre of disc
N. of Sun's Equator.

Nov. I . . !
,, II . .
,, 21 ..
.. 30.. 1

24° 41' E
22° 33' E
19° 45' E
16" 57' E

4° 12'
3° 7'
1° 55'
0° 49'

The Moon

:—

Date.

Nov. 4 .

D First Quarter

39 a.m.

.. 12 .

0 Full Moon

II a.m.

,, 20 .

d Last Quarter

34 a.m.

.. 26 .

• New Moon

47 p.m.

., 10 ..

1 Apogee 252,500 miles

48 p.m.

., 25 ••

1 Perigee 223.000 ,,

12 p.m.

-The following are the brighter
occulted stars visible from Greenwich. It will he noticed
that the 1st magnitude star .Mdebaran is occulted on the
13th, disappearance taking place about i hour after
moonrise.

l>ale. 1 Star's Name.

1 Disappearance.

Reappearance.

MaK. '

Moon's

Anple

Angle

Age.

Mean

IroniN.

Mean

froniN

i Time.

point.

Time.

point.

pm.

p.m.

d. h.

Nov. 1 21) .Sagittnrii

55 6-5«

140°

7.29

207°

4 12

,, 4 42 Capricorni

5'3 : JO.S.S

8c,-'

11.55

232°

7 '6

., 5 <r Aquarii .. ..

4'8 10.59

75°

12.4

240°

8 16

7 27 Piscium .. ..

50 730

35°

8.42

273"

10 13

,, 13 « Tauri . . ..

I'l 6.35

32°

7.16

299°

16 12

,, 14 115 Tauri .. ..

5'4 j 6.49

75"

7-44

264"

17 12

The Planets. — Mercury (Nov. i, R.A. 15''
Dec. S. 19"' 7'. Nov. 30, R.A. 17"' 55m ; Dec. S. 25"' 33' j
is an evenmg star in Scorpio at greatest easterly elon-
gation on the 27th, when he sets at 5 p.m. This elonga-
tion is very unfavourable on account of the great southerly
declination of the planet.

Venus (Nov. i, R.A. la'i 5111; Dec. S. 3' 44'.
Nov. 30, R.A. 15'' ym; Dec. S. 10" 26') is a morning star
on the confines of \'irgo and Libra. The planet is not
well placed for observation.

Mars (Nov. i, R..\. u/ 17m ; Dec. S. 24' (>'. Nov. 30,
R.A. 20'' 49"" ; Dec. S. 19' 19') is visible in the S.W. for
a few hours after sunset, but as the apparent diameter of
the planet is now small, it is not a very suitable object
for observation in small telescopes.

Jupiter (Nov. i. R.,\. 4I' 10"' ; Dec. N. 2o''o'. Nov. 30,
R..\. 3»'55"' ; Dec. N. 19 19') is describing a retrograde
path between Aldebaran and the Pleiades. The planet
is very favourably placed for observation, being in oppo-
sition to the Sun on the 24th, and is the most con-

spicuous object in the evening sky looking S.E. The
equatorial diameter of the planet on the 25th is 49"'4,
whilst the polar diameter is 3"-2 less. The following
table gives the satellite phenomena visible in this
country, before midnight : —

<fl

1
c

P.M.'s.
II. u.

P M.s,
II. u.

1 P.M.'s.

CL H. U.

Nov

Ec. D.

9 7

Oc. R.

8 I

II.

Sh. I. 9 7

Oc. K.

11 5'

111.

Oc. K.

7 41

11.

Tr. I. 9 10

Tr. I.

6 ,7

■ 6

Sh. I.

6 29

11.

Sh. E. II 42

Sh. E.

8 36

Tr. '.

6 55

11.

Tr. E. II 42

Tr. E.

0 8

Sh. L

9 4

Oc. D. 9 17

III.

Sh. I.

11 15

Tr. E.

9 26

Oc. R. II 29

11.

Ec. D.

9 3«

Sh. I.

10 II

11.

Ec. R. 6 28

Ec. D.

II I

Tr. I.

10 24

Tr. I. 6 32

11.

Sh. E.

6 26

Ec. D.

7 25

Sh. I. 6 34

11.

Tr. E.

7 II

Oc. R.

9 45

Tr. E. 8 44

Sh. I.

8 17

Sh. E.

6 53

Sh. E. 8 47

Tr. I.

841

Tr. E.

7 I

Ec. R. 5 57

Sh. E.

10 30

III.

Ec. U.

9 II

11.

Tr. I. 11 25

Tr. E.

10 52

in.

Oc. R.

10 57

11.

Sh. I. II 45

" Oc. D." denotes the disappearance of the Satellite behind the disc, and
" Oc. R." its re-appearance ; '* Tr. I." the ingress of a transit across the disc,
and "Tr. E." its egress; "Sh. I." the ingress of a transit of the shadow acro!=s
the disc, and " Sh. £," i*s egrcs.s.

Saturn (Nov. i, R. A. 21'' 56""; Dec. S. 14° 19'.
Nov. 30, R. A. 21I1 59""; Dec. S. i4'^o') is best observed
immediately after sunset, being due south at 6.20 p.m.
on the 15th. Telescopically, the planet with his rings is
a beautiful object, and on account of his low altitude the
position for observation is a most comfortable one. The
apparent diameter of the ball is i6"'o, whilst the major
and minor axes of the outer ring are 39"'r) and 7"'g
respectively, the ring appearing well open.

Uranus (Nov. i, R. A. 18'' 6™; Dec. S. 23° 42') sets
shortly after the sun, and hence is not available for
observation.

Neptune (Nov. i, R. A. 6'' 44""; Dec. N. 22° 5') rises
about 7 p.m. near the middle of the month, and is due
south about 3 a.m. The planet is situated in Gemini in
a region rich in sr.nall stars, thus making identification
somewhat difficult in small telescopes.

Meteors: —

The principal showers of meteors during the month
are the Leonids and Andromedids ; the Moon will some-
what interfere witii observation of the formor, but the
latter shower occurs in the Moon's last (juarter ; more-
over, the Andromedids may be numerous this year.

Date.

Radiant.

R.A.

Dec.

-Vov. 14- 16 ' 150"
Nov. 17-23 25''

4-22"

+ 43"

Swift, streaks.

(Gkeat Leonid

shower)

Very slow ; trains.

(Grbat Andromedid

shower)

Minima of Algol may be observed on the 13th at
9.7 p.m., and i6th at 5.56 p.m.

Telescopic Oujects : —

Double Stars: — >) Cassiopeia; o'' 43"", N. 57" 17',
mags. 3i, 7i; separation 5"-7. Hinary star.

X .\rietis i** 52'", N. 23''-6', mags. 4,H; separation 37".
Components white and blue; easy with power 20.

1 Persei 2*' 44™, N. 55 •2«' ; mags. 4, 8; separation 28".
The brighter component is orange, the other blue.
There are also several other fainter stars very near.

November, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

283

SUPPLEMENT.

[Although it has not been mual to include fiction ivithin the pages of " Knowi-RDGE," the folUming
discoHi'se, which is hut a tale Iniilt around a new and possibly impovtant scientific proposition, seems
to be one nut inappropriate to the contents of a scientific journal. — Ed.]

London's
TraLnsformation.

A Sxiggestive Sketch of Da^ys to Come.

By Tems 1)v\iri a.

CHAPTER I.

Introductory.

London ! That vast city sheltering .so many millions
of human beings, a far greater population than any
town at any time has contained. London, that pro-
vince of brick and mortar covering an area more ex-
tensive than that of any other two cities. London,
the great capital of the British Itmpire, which is the
largest, wealthiest, and most powerful nation the world
has ever seen. The central point of the land surface of
the globe, the link 'twixt the old world and the new.
Truly the " hub of the universe," if there be one.

A recent writer affirms that " Within the next ten
years there will have been added to London a greater
number of costly and important new buildings than in
any similar period since the re-building of the City
after the great fire of 1666." An extra half million of
inhabitants will have to be housed, besides those who
have been turned out to make way for the great
Government and other buildings already planned.

Can the life of London last? With an ever extend-
ing Empire, growing richer day by dav, to provide for;
with tr.ide and revenue increasing in proportion; with a
population doubling in half a century, the heart which
gives it life, the brain which gives it power, the
counting-house of its central management cannot ex-
tend its bounds without unwieldiness, except by the
adoption of some sweeping measure, such as the
Tushian scheme.

But, fortunately, so beneficial a design, effectually
neutralising present overcrowding, would extend
London's life.

Yet this vast collection of buildings is but a srrry
city. It is, whatever may be said to the contrary, but
a collection of towns. There is no centre, no one High
Street from which others radiate, no district to contain
all the chief buildings. It is an animal without a back-
bone, a tree without a stem. The streets are narrow
and overcrowded. The main arteries are congested
with traffic, and owing to lack of being systematically

laid down, have to be continually " up " whenever the
drains and wires buried under them receive attention.

Good healthy house accommodation, too, is wanted,
the slums need re-building, but they will not be re-
built so long as land is so scarce.

Moreover, it is a dirty place and is cursed with a
chronic fog, which chokes the lungs of its dwellers,
which darkens and saddens the homes it contains, and
which is said to cost at times from ;^5o,ooo tO;^ioo,ooo
a day in extra illuminants and in other ways. And
this fog is attributed to the murky river and its damp
bed, which traverses the great city.

In one of the latest books on Meteorology* we read
"In a city like London or Glasgow, where a great
river, fed by warm streams of water from gigantic
works, passes through its centre, fogs can never be
entirely obliterated."

A river running through a populous town cannot be
healthy. All the filth is washed down into the channel
and becomes collected there and its offensiveness dis-
seminated.

And this same river, too, not properly kept in hand,
has a way now and again of getting above itself and
flooding the low-lying streets. Everyone will remem-
ber (or, at all events, those that were in London at the
time now being referred to) the awful catastrophe that
occurred in the Underground railway about this time.
It may be as well to recall the main facts. Some
drainage operations were being executed on the Em-
bankment, when an unusually high tide swept away
some stones in the Embankment wall, which had
probably long been slightly displaced. The water
rushed through and flooded the excavation, and, wash-
ing away the earth around, at last burst in the brick-
work of the tunnel of the LInderground railway. This
had most appalling consequences. Several trains were
stopped. The water rapidly rose in height, some of
the passengers clambered on to the tops of the
carriages, while others waded and swam to the nearest
stations. But it was all in vain, for the tide was at
such a height that the level of the water reached far
above the platforms, and only a very few persons
succeeded in getting up the steps. And, what was
worse, the raging torrent rushed along the line for
miles, and soon found its way into the " tube " rail-
ways, where again whole train-loads perished. It
proved to be the most terrible catastrophe that ever
occurred in London.

Then if we go further afield it is surprising to find
that poor little ditch, the Thames, whilst greatly prized

* By Dr. J. G. McPherson.

284

KNOWLEDGE & SCIENTIFIC NEWS.

[NOVBMBI-.R, 1905.

and justly celebrated as a recreation ground for boat-
loving Englishmen, yet above bridge so narrow and
crowded, below so dirty and overrun with shipping.

And even here we are threatened with the possibiiitv
of further disasters. Has anyone calculated what
would be the consequence of the river, say at Kton,
rising three feet higher than it has done? Owing to
the gradual contraction of the hanks and wharfs in
London preventing a free flow, a sudden great rise,
such as might be caused by an abnormally heavy rain-
storm, would certainly have most disastrous con-
sequences on the towns and villages of the valley of the
Thames, and many thousands of pounds' worth of
damage would certainly be done, and there would be
great probability of a serious loss of life.

One more matter regarding this London and its
river. What if an invading army were to land in
England and advance against it ? Military geniuses
are full of their schemes for erecting forts on the hill
tops of the North Downs, but recent authorities tell us
that a river is the most efficient barrier, when properly
guarded, to the progress of an invading force. Yet
where is the desired river? The TTiames, as it is, does
us no good in the defence of London.

r?ut enf)Ugh of this commentorv on the wonders and
on the ills of London, and the Thames, and let us hear
how a great change came about at a period not very
clearlv located in the annals of the centurv.

CHAPTER H.

CORNELIL'S J. Tusil.

In one of the busiest corners of this busy city a
small group of men might have been observed. The
one on whom our attention must be fixed is a middle-
aged, rather short, clean-shaven man, with clear-cut
features, typical of shrewdness, if not cunning. His
clothes have the appearance of being well cut, and even
show signs of dandyism and a display of wealth. Vet
on closer examination they will be seen to be old and
well worn, and should have been discarded ere this by
a wealthy beau. Note, too, the face. Is there not a
shade of disappointment? Are there not evident traces
of failure and mental suffering? And who are his com-
panions? Just the ordinary typical City men, but evi-
dently from their manner they hold our friend in
reverential awe. Having finished their confabulation,
they respectfully take off their hats and pass away.

Bateson ! " called this man to one of the group, who
at once turned back, " Remember! don't mention my
arrival in this country till the appointed day. Mean-
while I reckon you know what to do." " Very good,
Mr. Tush," responded the other, " trust me." oo
they parted, and .Mr. Tush wended his way back right
through the City, and on, sadly and pensivelv, to the
south of the river. Still onward he goes towards
Lambeth, up one small street and down another, pick-
ing his way in the mud (for his delicately-made boots
are worn and broken out in places). There is much
mud here, too, for an exceptionally high tide has caused
the river to overflow, and for a day the streets have
been almost impassable. He turns up the steps of an
ordinary-looking little house fiver the front door of
which is a fanlight and a card inscribed with the word
"Apartments." Our friend knr>rks on the rusty
knocker, and a stout old female, with sleeves rolled up

and a dirty apron covering her portly front, opens the
door. A smile beams on her fat face as she recognises
the visitor, and taking from a small shelf two or three
letters, she hands them to him. The letters bear the
inscription " Cornelius J. Tush, Esq.," followed by so
many addro5.ses .scratched out and re-directions put in
that the poor postman must have offered a silent de-
precation as he endeavoured to decipher the desired
destination of the missives.

Cornelius ]. Tush ! Can this be the great American
millionaire? He with the world-wide reputation for
vast wealth and keen sagacity in all commercial enter-
prises? He, the clever son of the great " Hutton
King," Abraham Tush? .Aye, verily! but what a
come-down. His history of the last few weeks is easily
written. He had been li\ ing in domestic happiness and
luxury in his home near Philadelphia, when affairs
began to go wrong. His great scheme of the Cirand
C-entral Railway had failed. The Pacific Canal was
not yet near completion, although absorbing millions
of his invested dollars. The inventor he had set to
work to experiment on a large machine, which was to
have revolutionised the world's methods of trav<'l, had
at last to acknowledge that he was completely ballled
after expending some 500,000 dollars in experiments.
One thing after another had gone wrong, and Cornelius
had to own to himself that he was a ruined man.

Frantically he endeavoured to struggle against the
rising tide. All kinds of wild schemes did he propose
to his erstwhile disciples, but all New Vork had be-
come suspicious, truth will leak out ; and though no one,
of course, knew exactly where Cornelius' money lay,
or in what quantities, dark rumours began to spread
abroad, and people shook their heads and said to thcm-
.selves, " Avoid Tush." It was, indeed, a time to make
a man think; but Cornelius was a determined character,
and the more hopelessly he found himself sinking in the
mud, the bolder and more pretentious were his schemes.
He thought of his father's methods, which were to go
in for that which will .sell by the million, never mind
what it is or how small the article, so long as it sells by
millions. " Now look at buttons," he used to say,
" why, every man on the face of the globe, or no,
e\ery civilised man, has a dozen on each of his trousers
alone, and, then, look how easily they are lost ! "
Why can't one think of something new, something that
everyone needs, invent a boot sole that won't wear out,
or a new food that everyone would eat?

Well ! New Vork was played out, and with it ail
commercial America. Hut the name of Tush was well-
known in I'2ngl;md, and here, pf)ssibly, the sinister
rumours had not filtered through. He would see if a
'cute ^'ankec could not " hlulT " the Britishers. No
sooner thought of than the plan was.put into execution,
and Cornelius bade a touching farewell to his young
wife, the beautiful Alma l^alvine, and his little only
daughter, Libertia, and lof)k the boat to seek his for-
tune on the far side of the herring pond.

Arrived in London, Cornelius set to work to care-
fully reconnoitre his ground. He had m.-magcd to
bring away, as almost the last remnants of his great
fortune, what most people would c.ill a good round
sum of ready money, but this would ref|uirc to be very
carefully expended, :md he had determined to be as
economical as po.ssible so as to have the more when the
time came for definite action.

So for the first week he " lay low " in his miserable
lodgings in Lamb<-th, deciding that when all was ready
he could " cut a dash and set things humming."

But first of all it had to be noised abroad ih.il the

November, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

285

great Cornelius Tush was coming' over to London with
a view to investing- some of his millions in whatever
took his fancy. He proposed, then, getting into a few
big (if risky) undertakings, and selling out his shares
before paying for them. His was a name to conjure
with and he a good prestidigitateur. Bateson, a man
with a great reputation for shrewdness in business,
though for nothing else, was acting as his chief agent
in the matter. London happened to be in the right
state, too. An air of speculation was rife in the City.
Things were prosperous, and new schemes were finding
favour.

Having then got the news about that he was shortly
to arrive, the great man was to appear upon the scene;
not, of course, as the sordid, broken-down failure, but
as the American Crcesus, with so much money that he
didn't know what to do with it all. Then he would
make a great display of wealth so as to bear out his
reputation, and thus would he take the place by storm,
and become again, in fact, a multi-millionaire.

CHAPTER HL

The Dinner.

This much, then, had been done, and Cornelius was
now about to issue forth from his chrysalis state into
the splendid butterfly. A mass of correspondence had
passed between the Tush agents and all sorts and condi-
tions of people organising new ventures. Many of the
schemes suggested were, of course, absurd; many more
mav have been sound enough, but they were not of the
sort required; that is, they were not the gigantic under-
takings worthy of the notice of such a magnate. Sifted
down, there were some ten or a dozen concerns worth
consideration.

There was Singman's World Emporium Syndicate
for the conversion of his alreadv targe business in
Islington into a colossal City establishment.

Then Lord Henry FitzEdmund, that shaky old outcast
of the aristocracy, had got together a small syndicate
of nobodies with high-sounding names, in the hope of
building a large new Theatre, a Palace of Varieties,
such as would dwarf all the old-established places of
entertainment.

The European Hotel Company, under the manage-
ment of the well-known M. Jean Rideau, wished to
open a grand new hotel in some central situation.

There was the good old Lord Whittingbourne, with
his proposal for housing the poor; not suggestive of
much money-makjng, but a huge scheme which would
cause millions to pass. Besides all these were a new
tramway company, a great building syndicate, and
many more projects which need not be recounted.

It was difficult, indeed, to see how it was possible
for Tush to set them all going. Most of them re-
quired capital, and he had none. But, then, his name
might secure others who had ; anyhow, they were all
big things, and something might be got out of them.
Tush always avoided involving himself by talking
matters over too minutely, but preferred (having heard
or read all details of the scheme) to leave matters in
such a vague, uncertain state, that no one quite under-
stood how much or how little he had become identified
with the project.

He was now to meet the various promoters. The
best way to do this, he decided, was to ask them

each to dinner " to talk it over." If they came and
did themselves well, they would return thinking all ivai
well, even though nothing whatever had been definitely
settled. So all the principals were invited to a great
banquet (called a " quiet dinner ") at the Savile Hotel,
where the millionaire had now taken up his quarters.
How all this was to be paid for Tush alone knew, but
it was not difficult for a man with such a name and
fame to get together a few thousand pounds. Accord-
ingly, one day, the butterfly burst forth from the
chrysalis, and even mine host of the Savile, accustomed
as he was to wealthy and particular customers, was
aghast at the sumptuousness of living displayed.
Wherever he went Tush was most lavish with his
money. Cabmen were always paid (before strangers)
in gold. Waiters received handsome gratuities.
Beggars had sovereigns flung to them. Everything
was done to display his wealth. The visitors that
called had always to be supplied with the best cham-
pagne and choicest cigars. The finest suite of rooms
in the hotel had to be reserved, three or four servants
were specially told off solely to wait on the great man.

Then came the dinner. Each item was of the
choicest and the costliest. No money was to be spared
in serving the most magnificent repast that could be
procured. A large private dining-room was engaged
for the occasion. Superb table decorations were tastily
arranged on the groaning board. Menus, engraved on
solid silver in the form of a suitable souvenir, were
supplied for each guest to take away with him. It
almost got to the stage of the proverbial city feasts,
where a bank-note was placed under every plate
(though, in reality, these would not have been so easy
to supply, credit for such not being so readily obtain-
able).

The guests duly arrived and were ushered into the
presence of their munificent host. A few well-chosen
words greeted each of the patrons of progress, and
shortly the distinguished company trooped into the
great dining-room, resplendent with its dazzling display
of sumptuousness and wealth. So the brilliant banquet
commenced. Lord Whittingbourne, on Tush's right
hand, eagerly discussed his philanthropic scheme,
which, as he pointed out, required more capital than
he had originally estimated for, since he had come to
the conclusion that a good central site for the building
was most essential, as "the working man ought, without
doubt, to be near his work. On the other side the
Chairman of the European Hotel Company quizzingly
referred to the dinner that he would eive in return when
their great London Hostelry should be opened, wnue
Lord Henry, with a satanic grin, wished his grand palace
of entertainment was ready for them all to repair to
as a fitting finale to the programme. The various
schemes were each privately referred to during the
course of the evening, but little was promised. " Well,
we must see what we can do," was the usual vague
yet encouraging reply of Cornelius.

The party finally broke up in the best of spirits.
Each of the guests considered that he, and he alone,
had the ear of the all-powerful Tush, looking upon the
others as mere guests .with no special object to achieve.
They all rolled off in their hansoms, cigar in mouth, to
instil hope into their respective confreres awaiting them
at their clubs.

Thus passed off one of the most notable dinners of
the day. Ostensibly full of promise of great things,
yet, in'realitv, it might have been barren of results nad
not the mind of Tush happened to hit upon that great
idea which proved so far-reaching in its development.

286

KNOWLEDGE & SCIENTIFIC NEWS.

[November, 1905.

CHAPTER 1\\

The Great Idea.

Cornelius, with heavily-burdened mind, strolled out
alone on to the Embankment. Revolving over in his
mind the various proposals, he noted that there was
one peculiar feature which happened to be common to
nearly all of them, which was that they had as their
main requirement a large plot of land centrally situated
in London. This was all very well, but the place was
altogether too crowded as it was. Cornelius was sad,
sad because he was baffled. Vet he felt confidence in
himself. Past experience told him that expedients and
remedies always came eventually to his ever-ready
brain; so he lived in hope. He sauntered on along the
broad Embankment with its plane trees and dolphin
lamps. Many a miserable creature did he pass, skulk-
ing along or huddled on a seat. These people did not
possess such confidence as his. It is true they found
bread was wanting, and lived in hopes of its coming
spontaneously to their mouths, rather than that ideas
should come to their minds. They thought of present
wants, Cornelius only looked to the future. With
prospects of impending happiness and plenty we can
easily struggle through troubles and hard times, but
when there are no prospects, what is one to do? " Turn
your mind over," mused Cornelius, " plough it up like
a cornfield, put in the seeds, the ideas, the data, and
a crop will surely grow." Well, what were the seeds
to l>e? What was required? If only an acre of City
land could drop down from heaven and plant itself in
its proper place, then all would be well, that is, if
Cornelius owned it. He wandered on towards that
great beacon shining in the sky; that outward and
visible sign of the inward and spiritual brain of the
Empire, the Clock Tower at Westminster. Here he
met the busy, hurrying stream of transpontines making
their way homeward, and, carried as it were by the
stream, he, too, moved on to the great wide bridge.
Possibly because his mind was absorbed, his instmct
was leading him to his late home. At the centre of
the bridge he stopped and paused to gaze upon the
sight presented looking down the river towards the
City. The thousands of lights of all colours ! The
gas lamps, the blue electric lights, the red and green
railway lamps, the lurid glow of the illuminated streets
beyond, and then their reflections in the great black,
surging stream below. How weird that looked ! How
many people at the lowest depths of despair had there
gazed and then thrown their vile bodies into the muddy
swirl to end for ever their earthly miseries ! Cornelius
thought of this. Had he, too, come to that pass?
Should he, too, find his death in the gloomy depths, or
could he there find the first shooting blade for his
mental cornfield? " .Ah ! " he thought as he surveyed
that silent, vast expanse of emptiness devoid of people
or traffic, surrounded by crowded houses, yet itself
nothing but expanse, a layer of waters stretching so
far away to the distant lights lining the south bank,
"If that were onjy dry land ! "

The seed has sprouted ! The merest speck of green,
but there was a speck, and might that not become a
blade? " Only luridf " Could it not be utilised as
such? Could it not he made land? Here he was
standing on solid enough ground with the water flow-
ing beneath him. Could it not all be bridged over and
houses built on the bridge, even as they were in the
days of ancient London Bridge? The river would then
be but a huge sewer. What size of pipes would it re-
quire to carry that great flow of water? But then,
might not the pipes be distributed about under the

great City; or could not an enormous tunnel be con-
structed, deep down, below the level of the " twopenny
tubes"? Really, there seemed promise in all this.
The Thames, caged and tamed, and made to go where
man may will ! Then why not divert its course, lead
it out into the country, and leave all that great area of
City property dry, and available for building?
Cornelius fairly gasped. It was a huge idea that had
struck his brain. .'\n idea that must be at once care-
fully fostered and matured.

For some time he remained leaning on the parapet
deeply engrossed in his thoughts, oblivious to the
human stream that flowed steadily past him. Then
suddenly he stood up and looked around. " Yes," he
said, almost audibly, " it will be the biggest thing ever
heard of. My fortune is made." Then, after eyeing
carefully first one end, then the other of the bridge, he
briskly walked back, and having aligned himself with
the Embankment wall, started to carefullv pace the
length of the bridge. " Over 300 yards ! Then every
fifteen yards of river will give us nearly an acre of
ground. ^^ hy, there must be fully 300 acres between
this and the Tower ! Here is a site for Singman's
Emporium, for KitzEdmund's Theatre, and for all the
others put together. I can take on the whole lot, come
what mav. I'll write to them all tcS-morrow, and say
I can arrange for suitable sites ;/ they will nav me
price and not require immediate possession."

But what was to be the price? It would require a
big calculation. L'ndoubtedly the most practicable
scheme was that of deviating the course of the river to
flow through country fields instead of among crowded
houses. There would then be a huge canal to con-
struct. But though, perhaps, wider, it need not be
one-tenth the length of the Suez Canal, and, probably,
not so deep, unless, indeed, it were ft)und desirable to
make a s/i//> canal right round London. The land over
which the deviation must be cut would have to l>e
bought. This would require a large sum, since it would
involve the purchase of much house property. .'\nd
whereabouts was it to be? Which would be the best
course for the new river to flow to the sea ? Where
was the lowest lying country, or what would be the
size of cuttings through the hills?

Then what was to be done with the reclaimed land,
which would be wide enough for, perhaps, four parallel
streets? The bed of the river could be filled in, to
b me extent at least, with tiie earth got from tiie cuttings.

There is, too, the river traffic to be considered. All
those barges and steamers must go somewhere, else
enormous compensation would be demanded. But they
don't take up all the river, .'ind a narrow portion could
be left as a canal for the water-borne trade of London,
while communication between the upper and lower
reaches of the river could be continued on the de\iation.

Railways, drains, electric wires, and such like rould
be laid along the bed of the river and built over.

Yes, all this would truly require enormous funds, still
it had its merits, and a good thing can alwavs be run
if it is properly worked. The capital is there, some-
where. It only needs to be got hold of.

ICvidently the way to set about it is to form a huge
company. .Advertise enough, make the most f)f all the
various advantages to be gained, anti all the different
ways in which money is to be made out of it (,ind men-
tion none of the dilTirultics or possibilities of failure),
and the capital will be forthcoming.

Thus did Cf)rnelius conceive his crop sprouting up,
and visions of the h;irvost he would some day reap
hauntf-rl him throughout the night.
fTo be continued. )

287

KDomledge & Seientifle Nems

A MONTHLY JOURNAL OF SCIENCE.

Conducted by MAJOR B. BADEN-POWELL, F.R.A.S., and E. S. GREW, M.A.

Vol. II. No. 13.

[new series.]

DECEMBER, 1905.

SIXPENCE NET.

CONTENTS.— See Page VII.

TKe Greact Gnomon
a^t Florence.

By W. Alfrud Parr.

Of the crowds of worshippers who, on Midsummer
Day, yearly assemble beneath the vast dome of the
Cathedral at Florence to commemorate the festival
of San Giovanni, the patron-saint of their city, but

Fig. I.— The Cathedral (Sta. Maria del Fiore) at Floreoee, from the
south ; showing the window in the lantern to which the Qnomon
is attached.

few probably give a thoutjht to the astronomical signi-
ficance of the day they are celebrating. Yet Brunel-
leschi's wonderful dome — over 138 feet in diameter,
and, with its lantern, 387 feet high* — which marked an
epoch in architecture, and was the first great triumph
of the Renaissance, forms, with its famous gnomon,
placed there by the Florentine cosmographer Paolo
Toscaneili about the middle of the 15th century, un-
doubtedly the most stupendous astronomical instru-
ment for determining the summer solstice that the

* The corresponding dimensions of the dome of St. Paul's are
112 feet and 364 feet respectively.

world possesses. So, at least, thought the great
Lalande in 1765, when he wrote : " La meridienne que
Ton voit dans la Cathedrale de Florence est le plus
grand monument d'Astronomie qu'il y ait au monde. "
But that was some 30 years before his countrymen
gave to the world, as an earnest of the eventful ex-
pedition culminating in the Battle of the Pyramids,
that memorable work, the " Description de I'Egypte,"
which has formed the starting-point for our pre-
sent day knowledge of the design and orientation
of many O'f the great temples on the banks of the Nile.
Compared with some of these, the Florence " Duomo,"
considered as a solstitial instrument, must take a very
subordinate position in regard tO' the length of the beam
of light utilised.

The temple of Amen-Ra, at Karnak, for instance,
was, according to Sir Norman Lockyer, oriented tO' the
summer solstice in such a way that the setting sun
flashed a beam of light along its huge axis, something
like 500 yards in length, into the sanctuary at the ex-
treme end, heralding to the priests the commencement
of a new solar year, and affording them, at the same
time, an obvious means of impressing the multitude
with a " Manifestation of Ra." -A^t Florence, it is
true, Toscanelli's solar apparatus plays no part in the
structural scheme of the grand cathedral in which it is
placed, although the idea of utilising the ample propor-
tions of a vast public edifice in the interests of astro-
nomy is the same. At Florence, moreover, " the sun
had from the South to bring solstitial summer's heat,''
and thus mark his greatest northern declination from
the equator instead of being required, as in the sun-
god's temple, to register his greatest northern ampli-
tude along the western horizon. The method here
adopted is, indeed, the venerable one of the gnomon ;
and, having regard to the fact that the Florentine con-
trivance is higher than the similar apparatus in the
churches of S. Petronio, at Bologna (which, by the way,
was constructed in 1653 by the first Cassini, the dis-
coverer of the chief division in Saturn's Ring), S. Maria
degli Angeli, at Rome, and St. Sulpice, at Paris, put
together, Lalande 's claim for it may not be so far from
the truth as regards this particular form of solstitial
instrument.

Situated at a height of nearly 300 feet above the
floor of the Cathedral, and firmly built into the marble
sill of the southern window in the lantern surmounting
the dome, Paolo Toscanelli's famous gnomon must cer-
tainly have constituted, together with its solstitial
marble let into the pavement far beneath, a very effi-
cient instrument of precision in the days that preceded

KNOWLEDGE & SCIENTIFIC NEWS.

I December, 1905.

the introduction of the transit-circle. '■= This is evi-
denced by the fact that its illustrious author, who prob-
ably constructed it in 1468, shortly after the completion
of the Cathedral, obtained by its means a verv accurate
value for the obliquity of the ecliptic as then existing ;
his result of 23° 30' being- a more exact figure than the
23° 28' found by Furbach and his brilliant pupil Regio-
montanus. \\'hether, however, the gnomon was erected
by Toscanelli with a view to determining the variation
in obliquity, as maintained by Leonardo Ximenes and
others, is a question to which Celoria' considers no
positive answer can now safely be given. The supposi-
tion in itself would involve nothing unre.-Lsonable, for
this graduaJ variation in the obliquitv- of the ecliptic,
which the modern examination of ancient monuments,

as well as other researche,s, lead us to conclude was
suspected even among some of the ancients, was cer-
tainly known in Toscanelli 's day, and it is, therefore,
improbable that this remarkable man, who was the
author of the map used by Columbus on the voyagt;
which resulted in the discovery of America, should not
have borne this matter in mind when constructing his
great gnomon.

Nevertheless, the mean annual diminution in obliquity
being something like o".468, the chief factor — time-
in so delicate an investigation as this would neces-
sarily be, carried out with the means then obtainable,
would be ;dl but absent. Here, again, the Kgyptian
sun-god might assert his superior claim to be heard in
matters astronomical, for the great temple of Amen-Ra

• Introduced about 1600 by the Danish astronomer, Olaus
Romer, who 6rst measured the velocity of light.

t Sulle oiservaxi'ini, etc., fatti da Paolo Dal I'ozzo TouantW ,
Rome, 1894.

having stood for over 50 centuries, its solstitial orienta-
tion now shows a deviation of something like one
degree ; whereas with the Florence Duomo, which can
only boast an existence of a little over four centuries,
the observed variation, being comparatively small,
would be a maticr of considerable difficulty to accu-
ratcJy determine, even supposing the gnomon never to
ha\e l>cen displaced from its position, which, as we
shall presently see, is unfortunately not the case.

The task which Toscanelli had priniarih- set himself,
howe\cr, was undoubtedly the correction of the .\lphon-
sine Tables, which were then in operation, but which
gave a very inadequate representation of the true solar
motion, more especially as regards the exact length of
the tropical year. To correct this error, he knew that
it would be necessary to institute regular ot>servations
of the sun's motion, and it is for this reason, in all
probability, that he undertook the construction of the
gnomon. This ehiborate care to determine the exact
moment of the summer solstice in the Florence Cathe-
dral is~not without its significance in view of the annual
illumination ol the dome on Midsummer Night, or the
feast of St. John the Baptist ; and the S/. /a/in's fires,
kindled in tormer times in celebration of the summer
solstice, now find their analogue in the displav of fire-
works, which, to the modern Florentine, forms the
chief attraction to the festivities annually observed in
honour of his patron-saint, San Giovanni.

.As it is, many valuable facts relating to the history
of the gnomon have unfortunatclv been lost, for the
origin.'il inscription on the marble disc marking the
solstiti.'il point, which Toscanelli caused to be let into
the pavement of the north transept of the Cathedral,
was all but obliterated even in the lime of I,c<inardo
Ximenes, whose curious description,'" published at
l^'lorence in 1757, still forms the classic work on this
subject. Surrounding Toscanelli 's solstitial disc, and
placed eccentrically to it, is a larger circle of a different
kind of marble, on which is inscribed the date MDX
I'RIDIK ID I\'XII (i_nh June, 1510), the day on
which the sinnmer solstice fell in that year, owing to
the displacement of nine days produced by the Julian
Calendar which was then in force, the Gregorian Re-
form not licing introduced until o\cr 70 years later. t
This larger circle is thought to be the work cither of a
nephew of Tf>scanelli, or, more probably, of a certain
Antonio Dulciati (who is said to have written on the
reform of the Calendar), and is intended to mark the
position of the round patch of light which the sim's
ravs, passing through the circular orifice of the gno-
mon in the lantern, loniied on the lloor of Ihe Cathedral
at the time of the summer solstice.

As a matter of fact, both the large and the small
circle lie somewhat to the west of the true meridian,
thus anticipating the exact time of mid-day by about
a minute and a half, and it was partly this error which
induced Leonardo Ximenes to draw the meridian line
which extends for over 30 feet along the pavement.
Ximenes, indeed, whf> was the founder of the Ximcnian
Observatorv in Florence — the institution which still
retains the curatorship of the gnomon — not only made
important researches in its histon.% but hiinself insti-
tuted a series of very careful experiments with this huge
sundial. Besides tracing a true meridian, and causing

' Dil veuhio e nuovo Gnomone fiorenlino. (It is interesting to note
that Florio in his quaint Italian-KnKlish Dictionary, A IVorlde 0/
Wordii, defines the Italian gnomone as " the know-man or gnowman of
a diall. the shadow whereof poinlelli out the howers.")

t Viz., in 1582. The Reform was not adopted in England until
1752

December, 1905.

KNOWLEDGE & SCIENTIFIC NEWS.

289

both this and the solstitial marbles of his predecessors
to be covered. with a protecting brass,* he at first re-
adjusted and then replaced Toscanelli's gfnomon by a
new one of the same dimensions in every respect ; his

avowed object in bestowing- so much care and thought
on the apparatus being to bequeath to posterity a
means of detecting the slow changes in the obliquity
of the ecliptic — the cxiguae edipiuae variaiiones. as he
very aptly terms them in the long Latin inscription
which is affixed to one of the four massive piers sus-
taining the dome.

But Ximenes' grand design of handing on to future
generations an amended edition of this stupendous in-
strument of research was soon to be frustrated, for
even his careful corrections were not suffered to remain
undisturbed. During some repairs to the lantern his
gnomon was removed, and deposited for several years
ill an adjoining museum ; and, although subsequently
restored to its position, it was not brought into proper
adjustment until 1893, when Padre Giovann(jzzi,t the
present Director of the Ximenian Observatory, again
went over the entire work with the greatest precision.
Certainly a gnomon subject to fewer vicissitudes might
have been obtained had it been possible to carry out
the project, once entertained but dismissed as danger-
ous, of perforating the great dome itself.

Graver difficulties, however, than those occasioned
by the hand of the restorer conspire tO' render this great
solstitial instrument now of small value other than an

* This had not been raised for fome years, but at my request
Signer Pratellesi. the secretary of the Cathedral Office rf Works,
most kindly had it removed on the occasion of the summer solstice
on June 21st last.

t To whom, as well as to the Vice-director, Padre ."Vlfani, I am
indebted for much historical information.

historic one. The fact that only for a little over two
months at the time of the summer solstice, can the
gnomon be used at all, on account of the normally
lower altitude of the sun causing its rays to strike the
arches of the dome, would not necessarily impair its
scientific value; but the beam of light itself, transmitted
through the i|-inch aperture of the bronze gnomon,
is far too seriously affected by atmospheric perturba-
tions, caused by the varj'ing temperature along its ex-
tended path from lantern to pavement, to throw more
than a very unsteady image on to the meridian below,
while that image also, being over four feet in diameter,
is of little practical utility from an astronomical point
of view; moreover, the expansion due to the sun's
heat on the vast building itself would render minute
.nccuracy out of the question.

On the few occasions on which the solstitial observa-
tion has been made in recent years, the object has been
mainly to detect any slight movement which might
have taken place in the fabric of the great Cathedral;
and when after the severe earthquake shock of 1895
it was found that the trifling errors in position noted
may well have been due to the errors in observation
inseparable from this mode of investigation, anxiety for
the safety of Brunelleschi's wonderful dome gave place
to admiration for the work of its architect. To
enhance the effect, it is usual, when carrying out the
experiment, tO' provide the lantern with a temporary
iloorinir, allowing onlv the beam of light from the

orifice in the gnomon to pass down on to the pavement
iDelow, while the transept containing the meridian is
also darkened, in order to show the disc of sunlight
with greater precision.

290

KNOWLEDGE vS: SCIENTIFIC NEWS.

[DliCEMBER, 1905.

Grandly impressive as is the spectacle of the long
beam of sunlight falling- athwart the darkened Cathe-
dral, it is, nevertheless, only too true that the "pagean-
try of Nature " has n oplace in the science of to-day, and
such inveslig:ations as the dcsig-ners of the g-nomon
had in mind are now conducted with greater accuracy,
if with less magnificence, at the transit-circle of every
properlv equipped observatory. We now know that
the gradual change in the tilt of our planet's axis to the
plane of its path round the sun, or the ecliptic, which
the f'lorence gnomon was to register for successive
ages, occupies a cvcle extending through many thou-
sand years, and it has been calculated that this tilt was
at a maximum about 7200 B.C.. or 9105 years ago,
when the inclination of the equator to the ecliptic, or
" obliquitv of the ecliptic," amounted to 24° 13'. The
obliquity i.s at the present time* 23° 27 / and will reach
its minimum of about 22° 30' some grxDO years hence;
a short enough period reckoned from the standpoint of
astronomy, but sufficiently long to outlast man's
grandest monuments— his most " gorgeous palaces and
solemn temples," be the latter dedicated to Amen-Ra,
as at Thebes, or to St. Maria del Fiorc, as at Florence.

A Sliding Pinnacle,

TliK photographs show two views o! a slice of a hill
which is gradually leaving the mainland and toppling
over at the same time. It is to l)e found near the
village of Hobden (near Gras.sington), in Yorkshire,
and, according to the Postmasttr there, it must be

moving somewhat rapidly towards the valley, for not
many years ago it was a favourite walk of the villagers
on Sunday evenings to climb the hill and jump across
the narrow chasm which at that time separated it from
the mainland. Such ;i feat is, of course, impossible at
tlie present time.

No. I shows the appearance of the mass of falling
rock as one approaches from Hebden. The rocky rc-

■ The exact valne for Jane last was 23" 27' 5''.70.

mains of some former catastr()|)he rather pre\ent one
from obtaining a complete idea of the size and inclina-
tion of the slice, though the jointed and uncc|ii.illy-
wcathered nature of the strata is well seen.

No. 2 shows the appearance from the tnp of the
moor looking down towards Hebden, ;m<l i;i\cs a
better idea of the immense size and (l;mg<'ri)uslv over-
hanging state of the slice.

The surface rock is a hard gritstone, and the slipping
inav be attributed to unequal weathering of the s.ind-
stonr- l:i\cr = .

Dr. H. a. D. Jowf.tt, who ff)r nearly ten years has filled the
position of Senior Research Chemist on the staff of Dr. !•". H.
Power, Director of the Wellcome Chemical Research I.abor-
atories. is about to leave that position in conse()iicnce of his
appointment as chief of the I-^pcrimental Depirlment wt the
works of Messrs. Hurroughs, Wellcome & Co., Dartford, Kent.

.Messrs. Pastorelli & Rapkin, Ltd., have stnt us a copy of
their illustrated list of Meteorological Instrinnents, which they
have just issued. It comprises all forms of apparatus for
observation in this science, both of thest.uid.ard as well as ilic
selfrecordinK and registered patterns, and should bo in the
hands of both professional and amateur observers.

December, 1905.

KNOWLEDGE & SCIENTIFIC NEWS.

291

The R.ed Spot OLnd

SoutK Tropical Spot on

Jupiter.

The red spot has exhibited a very fluctuating rate of
motion during the past five years. In 1877 the rotation
period of this marking was gh. 55m. 33"4S., and it showed
an uninterrupted, though slightly variable, slackening of
speed until igoo, when its period conformed with that
adopted for System II. of Marth-Crommelin's Ephemeris,
viz., gh. 55m. 40-633. Since igoo, however, the rate has
oscillated between gh. 55m. 38s. and gh. 55m. 42s. In
the present year, as in igoo, the object has been running
nearly level with the rate of System II., and its longitude
has not differed materially from 26' since August, 1904.
The following are some observations selected from a
large number of transits obtained at Bristol in recent
years.

Year.

Date.

Transit
Time.

Lorfjitucie
of Spot.

Telescope and Power.

i8g8

June 7

9 20

25" 9

10 in. Reflector, 312

1899

Feb. 2

18 39

29-5

.. .,

Sept. 14

3 59

34'7

Dec. 30

17 54

35-7

1900

Feb. 20

20 59

37-4

Sept. 1

7 10

444

4 in. Refractor, 240

1901

Feb. 13

17 37

43-5

May 28

13 35

45'9

10 in. Reflector, 312

Sept. 29

5 54

436

1902

May 20

14 23

44 7

Dec. 31

5 <3i

36-3

1903

May 26

16 18

295

1904

Feb. 2

4 52*

360

Oct. 29

8 9

264

4 in. Refractor, ijo

1905

Feb. 2

7 3*5

254

Mar. 27

6 43

24 6

June 24

15 13

25 I

10 in. Reflector, 215

July 16

13 57

240

.. 30

15 32

23-8

I2iin. ,, 315

Aug. I

17 9

228

,. 18

16 14

23-1

Sept. 13

17 41

227

Oct. 6

" 43

238

.. 15

14 II

26-5

.. 17

15 47

25-3

14 55

258

.. -4

I 'J 37

28-2

Nov. 3

14 52

28-8

12 20

281

It >. ,1

.. 7

8 9

268

During the period under review the variable motion of
this marking has originated differences in longitude
amounting to about 23°. Marked accelerations occurred
in 1902 and 1904, while the motion was retarded in the
last half of 1903, and during the present autumn another
decided slackening appears to be in evidence.

To what cause these irregularities have been due
appears somewhat doubtful, but it has been conjectured
that a large dusky marking, first seen in the spring of
igoi, in about the same latitude (south tropical zone), and
moving at a more rapid rate than the red spot, has been
the means of quickening the speed of the latter. This
south tropical disturbance has a rotation period of nearly
gh. 55m. igs., and, as it overtakes and passes the red
spot, may well exercise some accelerating influence upon
it. There is indeed strong evidence to support this con-

clusion, but more observations are required. The two

markings were in conjunction in igo2 (July) and igo4
(June), and the phenomenon will be repeated in igo6
(May) if the rate of motion of the red spot remains
approximately the same as during the past twelve months.
Taking the mean rotation period of the latter marking in
recent years as gh. 55:11. 40s., and that of the south
tropical spot as gh. 55m. igs., there is a difference of
21 seconds in their times, and this indicates that conjunc-
tions must occur at intervals of about 700 days.

Between the present time and next April (Jupiter will
be very near the sun in May and June, igo6) it will be
important to secure a large number of accurately observed
transits of the red spot for the purpose of determining
whether there is any decided increase in its velocity.
The south tropical spot is now some 1 10° east of it (about
3 hours following) and the distance is rapidly closing up.
If, therefore, this south tropical disturbance is responsible
tor the longitudinal displacements of the red spot, the

Variations in motion of the Red 5pot during^ last eight years.

The diagram exhibits the variable motion in longitude of the red
spot in and since the year i8g8. The conjunctions of this marking
with the south tropical spot are also indicated. An inspection of
the diagram will show that the motion of the red spot appears to
have been accelerated at the time the south tropical spot was first
seen, and that both before and after the conjunctions of 1902 and
1904 great accelerations occurred.

fact will shortly become apparent in a marked increase
of the normal rate of the latter, and we shall find its
longitude becoming less.

In recent months the S. tropical spot has presented a
remarkable development, and its length has been aug-
mented from 43°'5 to about 60". My observations of the
p. and f. ends of this object during the past four months
have been as under : —

Date,
1905.

Longitude,
P. end.

Longitude,
F. end.

LenKtli.

August 7

I57'9

201-4

43 5

Sept. 13

1403

189-9

496

Oct. 19

"33

1719

586

1131

1705

57-4

Nov. 2

108-4

165-8

57-4

109 6

167-0

574

108-5

170 7

62-2

The increase of length between August 7 and October 19
was 15 ', which corresponds to a real distension of about
11,000 miles. This enlargement must have occurred

KNOWLEDGE & SCIENTIFIC NEWS.

[DnCEMBliR, UJO5.

chiefly at the following side of the spot, which has drifted
far East relatively to the rotation of gh. 55m. 19s., repre-
senting the normal rate.

While writing I may note that the present autumn
has furnished many excellent observing nights.
Between October 7 and 14 the weather was very
cloudy, but between October 15 and November 11
there were 22 nights clear and 6 overcast. On quite a
large proportion of the clear nights planetary definition
was found very sharp. This was especially the case on
November 6, when I tried powers of 713,912, 1210, and
1540 on my i2i in. reflector. The details could be well
seen on Jupiter' with the latter power; but the difficulty
of getting the image into the field, and keeping it there,
rendered the use of lower powers much preferable.

W. F. Denxi.ng.

Bristol, November 13, 1905.

Note or\ the Absorption Lines of
Wa-ter Va-povir.

0.\ comparatively rare occasions the spectrum of sun-
light exhibits very pronounced absorption lines due to
the atmosphere being very highly charged with water.

These rainbands are particularly prominent in that
portion of the spectrum which contains light of wave-
lengths between .000059 and .oooofK> centimeters, i.e.,
in the region extending towards the red from D about
one quarter of the way to a

When the pKJsitions of these bands are well known
they may be detected as faint lines when the air is less
heavily laden with moisture, but if the moisture is
excessive they form, after the sodium lines, the most
prominent features of the spectrum in the region
indicated. In London such occasions of excessive

°ua

AVSOKPTION

absorption occurred on June 17, 1902, June 6, 7, and 9,
and .September 6, 1905, and they were taken to fix the
position of the prominent bands as indicated in the
drawing.

At 59.20 and 59.26 occur two bands, each of them
triplets; at 59.45 occurs another triplet, ff)llowL-d by
five doublets, the last (A which is at 59.82. The atmo-
spheric conditions being favourable the best time for
the exhibition of these bands is in the early morning in
summer, picking np light from a low point in the I-^ast.
However, in June of this year there was nf) difficulty in
obtaining them at :my hour and at any altitude on the
6th and 7th day of that month.

Unsettled weather always accompanies these
strongly-marked bands, and their existence certainly
forms a very trustworthy warning of a bad day.

T. H. B.

The Zodia.ca.1 Light.

\\\ Akthlk Mee.

Mr. Mal .\uek has well shown in his " .X.slronomy
without a Telescope," that an object which requires
no instrument to study, which most people can see if
they try, and which has been observed for countless
generations, still remains to a great extent a mystery.
The object is the Zodiacal Light, that nebulous cone
which appears in the west after sunset in early spring,
and in the east before sunrise in late autumn, and
which, bright in the tropics, may still be profitably
studied in our less favoured latitudes by anyone whose
horizon is not troubled by the glare of artificial light.

Kepler, long ago, came to the conclusion that the
Zodiacal Light was an appendage of the sun, and his
opinion has on the whole, received the confirmation of
modern observers ; but much more remains to be done
before all the necessary data have been secured, data
which in no way depend on the telescope, but must Ix;
collected by naked-eye observers, aided by the virtues
of accuracy and patience.

It is not our purpose here to deal with the methods
of observing and studying the light. These are dealt
with fully in the charming work above referred to.
But we desire to call attention to some very interesting
observations just made by Dr. .Simon Newcomb, the
eminent American astronomer, which indicate, so far
as they go, that the Zodiacal Light lies to the north
and south of the sun as well as to the east and west of
our great luminary. Prior to Dr. Newcomb's ob-
servations no attempt has ever been made with success
to observe the Zodiacal Light to the north of the sun;
in fact, the feat is one presenting a good deal of dilli-
culty.

To begin with it cannot be done when the sun is
less than 18° below the horizon, on account of the
interference of twilight, nor must iS" be exceeded to
any great extent else there would not Ix; enough of the
light left above the horizon to be seen. In fact (as
Newcomb points out), unless the minor semi-axis of
the light considerably exceeds 18" it may be for ever
impossible to distinguish it from twilight itself. The
observation may best be made in latitudes such as our
own, but there must in addition be .'i perfectly clear
horizon, and the more elevated the post of observation
tlie better. Dr. Newcomb tells us that even in the
liear air of the United St:ites he has so far failed, a
fact which, in itself, indicites that the observation is a
most delicate one, demanding not (jnly a trained eye,
but the most perfect of local conditions.

Whilst in Hurope this summer the distinguished
astronomer determined to try his experiment amongst
the mountains of .Switzerland. Me therefr)re consulted
a Swiss scientist, who advised the Brienzcr Rolliorn, a
summit suitably situated, easily .■iccessible, and nearly
S.ooo feet high. Thither Dr. N'ewcomb repaired on
July 26, and made <areful observations on that evening
and also on the 29th.

At 10 o'clf)ck on the first of the evenings in ques-
tion the twilight had completely passed, but there was
a faint glow over the north-western horizon whii:h,
twenty minutes later, was 20" west of north. It after-
wards became well marked, and was watched mitil the
haze thickened and put an end to observation.

December, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

293

At midnight of the 29th the glow was again seen,
and Dr. Xewcomb made the following note : —

" 12 h. 5 m. to 12 h. 10 m. Local M.T. Tlx'
characteristic Zodiacal glow distinct and unmis-
takable— not so bright as ordinarily seen east or
west of the sun, yet several grades brighter than
the limit of doubt. It extends from a little east
of Capella to a region below the pointers. The
maximum of brightness is midway between Capella
and the north point, say between 10° and 150"
east azimuth and at 10° of altitude. The appear-
ance of maximum brightness below Capella was
evidently due to the Milky Way."
Dr. Newcomb (who also glimpsed the degenschein)
believes he has established the fact that in the direction
of the sun's axis the Zodiacal Light is brilliant enough
to be plainly seen to a distance of about 35° on either
side of the sun, and he suggests " that the Zodiacal
Light be hereafter described as a luminosity surround-
ing the sun on all sides, of which the boundary is
nowhere less than 35° from the sun, and which is
greatly elongated in the direction of the ecliptic."

The Aurora, of November 151h.

Bv W. Shackleton.

A FIXE display of the Aurora Borealis was witnessed
in London on the evening of November 15. I first
noticed the phenomena at 9.10 p.m., when the sky
about 150 W. of N. appeared illuminated by a crimson
glow, with occasional crimson streamers, shooting up
towards the zenith. The crimson appearance, how-
ever, did not last very long, and by about 9.30 p.m.
had entirely disappeared. I was not able to com-
mence spectroscopic observations until the crimson had
disappeared, and then I could not trace any red line,
but over a considerable area in the sky the green
aurora line was very strong, together with two fainter
lines more refrangible and apparently a continuous
spectrum in the blue violet; the region of spectrum less
refrangible than the principal green line appeared a
perfect blank. Prof. Fowler informs me that he com-
menced observation shortly after 9.20 p.m., and was
able to trace the green line until 11 p.m.; he also state.s
that on the same morning he observed a brilliant
metallic prominence eruption on the W. limb of the
sun, and, in addition, there was considerable activity in
the large group of spots, in the western hemisphere,
as indicated by the reversals and displacements of the
bright lines, more especially C. (Ha.)

R-oyal Geographical Society
Meetings.

Secemter ;«.— Exploration in the Abai Basin, Abyssinia. By H. Weld Blundell.
December 2«.— Exploration in New Guinea (u-idi Cinematonraph niuatrntion^i.
By C. G. Seligman.

other provisional arrangements are as follows :
Unexplored India. By Colonel Sir T. H. Holdich, K.C.M.G.. K.C.I. E., C.B.
The Economic Geography of Australia. By Prof. J. W. Gregory, F.R.S.
Survey and Exploration in Seistan. By Colonel A. H. McMahon. C.S.I. , CLE.
Exploration in Tierra del Fuego, By Captain Richard Crawshay.
Exploration in the East Tibet Borderlands. By Lieut. Filchner.
Explorations in Bolivia and Peru. By Baron Erland Nordenskjold.
The Philippine Islands. By Prof. AUeyne Ireland,
Northern Rhodesia. By L. A. Wallace.

The Geographical Influences of Water Plants in Chile. By G. F. Scott Elliot.
Maps of London. By Laurence Gomme.

By J. Lewis Bo.nhote, M.A., F.L.S., F.Z.S.,
M.B.O.U., etc.

.Xltmol'GH the literature on colour and coloration in
the animal kingdom has reached huge dimensions, and
the subject is one which has occupied zoologists from
the earliest days, yet we are still a long way from a
complete understanding of the causes and use of colour.
.\nd since any series of facts carefully collected, or a
suggestion, however slight, may prove a stepping-stone
towards a more complete knowledge of what are un-
doubtedly the most conspicuous features among
animals, I feel that no further excuse is necessary for a
paper of whose deficiencies no one is more conscious
than the writer.

On the one hand chemists and physiologists have
restricted their investigations to the extraction and
analysis of pigments, and on the other hand the
majority of zoologists have studied coloration from the
standpoint of its utility to the organism in its environ-
ment. Few, however, have considered the fact that
colour has probably its primary cause and utility in
satislying some physiological need of the animal, while
natural selection has come in secondarily and eliminated
the unsuitable, or perfected those colours and markings
that were able to be adapted for purposes of protec-
tion, warning, itc.

It is not my purpose here to enter into a long dis-
cussion, pointing out special cases where natural selec-
tion seems to have failed, or where its advocates seem
to have overstepped the limits of probability. This has
already been done by many writers, and although they
may have partially succeeded in showing that natural
selection is not sufficient to account for the cause of
coloration, yet their work has been, in the main, de-
structive rather than constructive, and it is probably
owing to this tendency that the physiological aspect of
colour is not more widely accepted to-day.

I do not, therefore, propose in this paper to deal in
any way with natural selection, but, rather, to bring to
light further evidence in support of the contention that
colour is primarily due to the vigour of an animal, so
that where we find conditions suitable to a high state of
vigour we shall there find a corresponding increase in
the colour.

Secondly, I shall try to show that many of the mark-
ings and longitudinal stripes on an animal will be
found to have their origin in certain spots, which I
propose to call '" poecilomeres," and I shall attempt to
bring forward considerable evidence to show that these
" poecilomeres " arise from physiological causes.

Those who have kept and studied live animals know
that the state of the coat or plumage is an unfailing
criterion of health or sickness, and that without any
moult a bird, on recovering from an illness, becomes
much brighter and more glossy, and I know of a case
in which the black plumage of a bird became quite
brown during sickness, and re-gained, to a limited ex-
tent, its black and glossy appearance with the retuin of
health.

We may, therefore, take it for granted that when an
animal's health becomes in any way affected, the change

294

KNOWLEDGE & SCIENTIFIC NEWS.

[December, 1905.

will be visible externally in the animal's coat or
plumage.

Before going further it would be well to define
exactly what I mean by vigour.

I prefer to employ a term which ha.s already been
used in a somewhat similar sense by Wallace and other
naturalists, rather than coin a new one*

By vigour is meant wh;it one would popularly describe
as " high fettle " or " condition." .\n athlete trained
for a race is full of " vigour " so far as his mu.scles are
concerned.

Physiologically speaking, however, I mean by " high
vigour " thai an animal's whole bixly is in that state
of physiological activity which would enable it to stand
severe strains and exertions without being adversely
affected.

" .Activity of nutrition and function " (the phrase is
borrowed from Dr. \. E. Durham, in Quain's Medical
Dictionary) is the best definition of what I mean by
" vigour."

So that :—

The colour of an animal will be primarily dependent
on its " activity of nutrition and function " being at
a high or low level.

.An animal's " vigour " is affected by several causes.

I St. CLIMATE. -A heading which may be again
sub-divided into

((?) Temperature.
(b.) Food supply.

2nd. The rise and fall nf se.xual activity.

In those animals whose vigour is not constant
throughout the year, the changes will take place in
rorrelrition with one or other of these causes.

The effects of the first we may call seasonal change in
contradistinction to the second or breeding change.

I now propo.se to consider the mammals and birds
according to the regions (Polar, Tropical, or Temper-
ate), in which they live.

1. — The Polar Regions.

In the Polar regions the period of extreme cold and
scarcity of food is so long as compared with the short,
bright summer, and the transition from the one to the
other sfi abrupt that the inhabitants thereof will be
subject to violent changes.

The winter follows so quickly after the breeding
season that there is no lime, as in more temperate
regions, for the animal to recuperate after the lowering
effects of sexual activity. .Such reserve material as is
formed will, therefore, be stored up in the ff)rm of fat,
a condition in which it is most accessible for any siib-
setiuerit demands that may be made upon it by the body.
Tliis storing up of fat, as Captain Barrett-Hamil-
ton has shownt, is f)ne of the concomitants of sluggish
metabolism. Here, therefore, we have conditions of
low vigour, and in cf)rrelation with them we find the
.inimals for the most part white or grey.

In the spring we would expect that the excitability
of the breeding seasf>n, as well as the higher tempera-
ture and more plentiful food, would fend to a high state
of vigour, but it must b<: remembered that the privji-
tions of the winter h.ive so lowered the animal's condi-
tion, that it is unable to derive full advantage from the
more favourable circumstances, and its vigour is,
therefore, unable to reach a high level. In correlation

with this we find a predominance of duller colours
amongst the majority of Polar animals.

How, then, are we to account for the darker animals
of these regions, as, for instance, the musk ox. pen-
guins, and raven?

If our suggestion holds good, the fact of these
animals being dark coloured in the.se regions proves
that they are able to maintain their full vigour through-
out the year, in spite of the cold and scarcity of food.*
\ow if this be so, we ought to find these animals
throughout the world equally highly coloured or more
so, or it is conceivable that if their " vigour " is so
great in cold localities, it might liecome too great in
warmer regions, and being unable to find any outlet for
this excess (the animal being already highly coloured),
death might ensuet, and such nniinais would, in con-
sequence, be restricted to the colder portions of the
world. The raven is a good example of the first of
these conditions, for the Corvida; exist practically un-
ch.inged throughout the world, and the musk ox and
lemming fulfil the second. The mouse hares (Ocla'tona),
although .Alpine rather than Arctic, give us a good idea
of seasonal change, and show us that the amount of
" \igour," rather than the climate, may affect their
colour.

For example, tivo species — O. ladacensis and O.
roylei — inhabit adjacent countries where climatic condi-
tions are very similar. Ladacensis is white, or nearly
so in winter, and light brown in summer, whereas
rnylci, which becomes bright red in summer, never be-
comes paler than iron grey in winter.

So that here we have two nearly-allied species in-
habiting the same country, each equiilly influenced by
the climate so as to cause them to undergo a seasonal
change, yet in winter one is white and the other — in
defiance of the laws of protection — dark. Captain
Barrett-Hamilton has also brought to my notice another
similar instance in the ca.sc of the .Siberian lemmings
(Dichrnstonyx and Lemniis), where the light or pro-
tectivelv-coloured species is much scarcer than its more
conspicuous relative.

The penguins, again, are birds whose nature is such
as to enable their " vigour " to reach its fullest extent
in .\ntarctic regions at all times of the year. It is not
surprising, therefore, to find several specimens, e.g.,
the emperor penguin, indulging in p.'ilches of bright
colours, such as yellow, orange, or red, thus affordins;
a further proof that " vigour " rather than " cjiniale "
is the prime factor in determining the color.ilion.

To carry our point further, we should expect to liiid
the vigorous, dark .Arctic species breeding e;uli<'r than
those that are paler coloured, .and in confirmation of
this we find the raven breeding very <"arly in .April,
while the ptarmigan antl grouse wait till the l:itter end
of .May.

The lemming is .another inst;mce, for it is .1 liriglitlv-
coloured animal, and in certain seasons produces young
more numerously and rapidly than .any other Arctic
animal, while as a result of this excessive " vigour,"
we find it most pugnacious and energetic.
(To be continued. )

•The following writers may be said to have written on the subject
from this standpoint, viz , Bateson. Barrett-Hamilton, Beddard.
Cnnningham, Geddes and Thompson, Newbigin, Tylor and
Wallace.

^Proc. Roy Irish Arad. Vol 24, Sect, B, Pi. 4, P 307(1903)

• It might be argued against this that in these cases, the colour
having been placed in the hair, it could not be withdrawn, and not
being harmful, but even, perhaps, useful (ashaslicen suggested for
the musk ox), the animal was enabled to survive. If these animals
only moulted in spring, such an argument might hold good ; but in
the case of the raven, the moult is in autumn, and I fancy the
same holds good for the penguins.

t The excessive cncigy of white men on first coming to the
tropics is a frequent cause of their overtaxing their powers, so
frequently culminating in drink or fever.

December, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

295

Seismoscopes.

Bv Charles Da\ isox. ScIJ., l'\(i.S.

Instruments desisfneci for the reg-istration of earth-
quakes may be divided into three classes : (i) those
which give the time of occurrence only; (2) those which
record and magnify the actual movement of the ground
without any determination of time or duration, and {3)
those which register the time, amplitude and period of
every vibration, so that the actual movement of the
ground may be completely realised. Those belonging
to the first class are usuallv known as seismoscopes, and
those of the second and third classes as selsntograp/is.
The latter as a rule are elaborate and costly apparatus,
and can only be constructed by skilled workers and
with the aid of refined tools. On the other hand, some
forms of seismoscopes may be easily and cheaply made,
and the errors due to home-manufacture are not of
much consequence. They establish, what is an impor-
tant fact, that a disturbance of some kind has taken
place, and, without much trouble, they may he made
to record its time of occurrence.

In a paper published in " Knowledge" for .August,
1896, a few suggestions were offered for the observa-
tion of earthquakes without instrumental aid. The
present paper, which may be regardv'd as a supplement
to the other, contains descriptions of a few of the sim-
plest kinds of time-recording seismoscopes.

Every such -,seismo.scope consists of two distinct
parts, one for magnifying the movements of the
ground, and the other for recording the time. In the
latter part, there is some, though not g^reat, varietv,
seismoscopes, otherwise different, making use of the
same kind of recorder. .\ good clock, or one the error
of which is known, is its essential feature. The
simplest tvpe of seismoscope is one in which some ar-
r.-ingement is made for stopping a clock, or starting
a clock (previously fixed at some known time), at the
instant when an earthquake occurs and attains suffi-
cient streng^th to affect the instrument. In the best
form of all, the record is made without stopping or in
any wav affecting the motion of the clock, and it is ob-
vious that, in a country where earthquakes are at all
frequent, this kind should be adopted whenever
possible. Even in Great Britain, nianv records may be
lost if the instrument is put out of action bv the first
tremor of a series. For instance, within seven hours
on the night of December 16-17, 1896. at least ten
earthquake-shocks were felt in the neighbourhood of
Hereford ; while, during a still shorter interval in the
early morning of September 18, 1901, one observer near
Inverness counted no fewer than twenty shocks.

Mallet's Seismoscope.

One of the earliest and simplest seismoscopes
adapted for stopping clocks was that devised by the
well-known seismologist, Robert Mallet. This is shown
in fig. I, in which .\ represents the bob of the clock
pendulum, B a piece of stout wire passing through the
centre of the bob at right angles to the plane in which
the pendulum oscillates, and CD a strip of wood, an
inch or an inch-and-a-half wide and a quarter-of-an-
inch thick, weighted at the end C, and turning freely
about a pin driven into the wall or some steady support
at the end D. This lath passes through holes in the
.side of the clock-case, and its lower edge is cut into
teeth in that portion which covers the arc of oscilla-

tion of the pendulum. E is a log of heavy wood, four
to fi\e feet in height and fi\e or six inches square ; the
lower end, which rests on the ground, is cut off square,
and the top is cut down to about a quarter-of-an-inch
square, so tliat the l:ith (' I) iiiav rest upon it. W'hrn

Fig.

-Mallet's Seismoscope.

the log E is o\erthr()wn by a shock, the lath C D falls,
and the teeth, catching the pin B, will stop the clock.*
The dimensions of the apparatus may obviously be
varied at pleasure ; its chief defect lies in the roughness
of the starter E.

Milne's Seismoscope.

Professor Milne's seismoscope is free from this de-
fect, in having a more sensitive arrangement for
dropping the lath C D. Instead of the column E
(fig. I.), he uses a simple horizontal pendulum EG C
(fig. 2.), which is more readily displaced by a weak
•:hock. The lath C [■) and the pendulum bob are ar-
ranged as by Mallet, but the lath ends at C in a piece
of wire. E C is a straight wire, passing through a

Fig.

disc of lead 1-". The end I'- is sharpened .ind rests in a
small conical hole m.ade in the head of a dr;iwing-pin
pressed into the side of the clock-case, and the wire
E C is supported in a horizontal position by a silk
thread G fastened to the clock-caAe at the upper end by

•In another form of seismoscope suggested by Mallet, two strings
pass from the log of wood through the sides of the clock-case, and
are fastened to the pin at the lower end of the pendulum. The
lengths of the strings are adapted so that, while hanging loose
within the clock case, they permit the pendulum to swing Ireely ;
but stop it immediatly the log E is thrown down by a shock

2g6

KNOWLEDGE & SCIENTIFIC NEWS.

[December, 1905.

a drawing-pin or nail vertically over the pin at-E. A
ver)' sligfht movement of the clock-case displaces the
wire E C, and the lath C D falls as before and stops
the clock.

Marvin's Seismoscope.

Professor Milne's si-ismoscope mav easily be con-
structed with home-made appliances. Tlie next two
instruments, designed by Professor C. F. Marvin and
Dr. G. Agamennone, are of less simple form. Pro-
fessor Marvin's seismoscope, which is in use in the
United States, is illustrated in fig. 3. A heavy weight
A is suspended from the frame B by means of a steel

File. 3.— Marvin's Seismoscope.

link C, which passes partly through the centre of the
weight. .At the bottom of the link is a small hole D,
into which fits the sharp point of a screw E rigidly
connected with the weight, and .so adjusted that the
point is just above the centre of gravity of the weight.
.At the top of the link is a similar pointed .screw F,
resting in a hole made in a projection G from the
frame B. When suspended in this manner, the weight
;\ is obviously in stable equilibrium. From the top of
the link C there projects upwards a slender and flexible
pin H, about six inches long. 'Hie upp<-r end of the
pin is tipped with platinum and passes through a small
hole (also lined with platinum) in the plate K at the
top of the instrument. This plate is electrically insu-
lated from the frame B, but is connected bv a wire with
one of the binding screws L fixed to the base. Tlie

position of the plate can be adjusted by means of four
screws M (onlv two of which are shown in the figure)
so that, when the seismoscope is in working order, the
tip of the pin H is exactly in the centre of the hole in
the plate. The binding screws L are connected with
the poles of a battery.

When an earthquake occurs, the frame B moves with
the ground, but the heavy weight .A remains nearly at
rest. The movement of the frame with respect to the
weight is magnified several times at the upper end of
the needle H ; and. if the original displacement is great
enough, the tip of the needle touches the side of the
hole in the plate K, and completes the circuit. By such
means, a clock may lie stopped, and, if desired, an
electric bell may be rung to give notice that the clock
requires attention ; or a record may be made on a strip
of paper moved bv clockwork.

The latter method is that which is employed in the
United States Weather Bureau, at Washington. 'Ilie
time-recorder there is the so-called " weekly anemo-
meter register." Tfiis consists of a horizontal cylinder
covered bv a sheet of paper and revolving by clockwork
once in six hours. .A pen rests lightly on the paper as
the latter passes underneath. The pen is connected
with an electro-magnet fixed to the base of the register,
and this again with the seismoscope, and, when the
circuit is closed during the occurrence of an carthqu.ike,
the pen is slightly, displaced to one side, and the record
of a shock consists of a notch in an otherwise uniform
line. Tlie paper is marked with lines corresponding
to intervals of five minutes, but, as the clock which
drives the cylinder cannot be depended on for keeping
accurate time, the electro-magnet is also connected
with a good pendulum clock so adapted that the circuit
is closed momentarilv once everv five minutes. "The
record of an earthquake," Professor Marvin remarks,
" consists of a succession, more or less prolonged, of
lateral jogs or strokes on the line traced by the pen.
whereas the clock record consists of a single stroke
occurring regularly and of very short duration." The
paper is dri\en at the rate of 2', inches an hour, and it
is thus not difficult to determine the time of a shock to
within a quarter or half a minute.

Agamennones Seismoscope,

.At first sight, there is some resenihl.nice hot ween Dr.
.Agamennone's seismoscope and Professor Marvin's.
The principal difference lies in the fact that the per-
forated plate is itself movable and magnifies the ori-
ginal displacenient of the ground. The seismoscope
is thus doubly sensitive. It is used chiefiy in Italian
observ.'itories, but is also to be found in Ilimgary,
Roumania, Bulgaria, India, the Dutch Indies, etc.

The base .A of the instrument (fig. .}.) is a cin-ul.-ir
plate of cast iron, standing on three equidistant feet,
two of which arc levelling screws. Three vertical rods,
B, C, and D, rise upwards from three points of the
base which form the angular points of an equilateral
triangle. Tlie rcxl B is made f>f stwl, and is about 74
inches long, the lower part. 2! inches in length, being
a thick steel wire, and the upper portion a fine steel
rod, Tj'jth of an inch in diameter, .'md ending at the lip
in a short platinum wire. .A lens-sh;iped disc of lead K,
weighing a little less than half-a-pound, is fixed by a
screw to the rod B near its lower end. 'ITie second
rod C is of twice the thickness of the other, and of
about the same length, and carries at its upper end a
similar disc of lead F, fixed to it by a .screw. To this
disc is attached a small horizontal plate of platinum O.
perforated by a small round hole and so adjusted that

SvPFLEMgNT TO " KxonxEDGE & SciEXTiJlc Seivs." December, 19(B.

Photograph of the Svin, October 22nd, 1905.

December, 1905.J

KNOWLEDGE & SCIENTIFIC NEWS.

297

the platinum tip of the rod B passes exactly through
Its centre. Thus, as both the rod B and the hole in
the plate G are subject to displacement, and as the rods

Fig. 4.— Agamennone's Seismoscope.

B and C have different rates of \ ibration, it is obvious
that a very small movement of the ground is sufficient
to bring the tip of the rod B into contact with the rim
of the hole in the plate G.

This forms the essential part of the apparatus, but
several details are required in order to adjust the tip
of the rod centrally within the hole. In the earlier
forms of the appiu-alus, the plate G was attached to an
arm springing Irom the rod C, and provided with two
screws at right angles to one another for making the
necessary adjustment. But, as the rod C vibrates
more rapidly than the rod B, it was found advisable to
transfer the adjusting apparatus to the latter. The
thick steel wire, which forms the lower part of the rod
B, is fixed to the bottom of a strong tube of brass H,
let into the base A. At the top, this tube ends in a
brass rmg, in which work two screws S and S, at right
angles to one another, which press against the thick
steel wire forming the lower portion of the rod B.
With this change, tlie necessary adjustments are made
more easily than in the earlier forms of the instrument ;
but, to attain this end still more rapidly, tlie stout rod
D is provided, by touching which the oscillations are
quickly damped.

The two rods B and C are electrically insulated by
discs of ebonite from the base of the apparatus, and
are connected with the binding screws K and L, and
these again with the binding screws of the seismoscope
clock. This is an ordinary clock, the pendulum of
which is drawn to one side and held back by a small
tooth at one end of a lever. Immediately the platinum
tip of tlie rod B touches the rim of the hole in the plate
G, the circuit is completed, an electro-magnet fixed to
the base of the clock raises the toothed end of the lever,
and the pendulum is thus released. If the clock is pre-
viously set at some known time, say twelve, the time
indicated by the clock when next observed gives the
time that has elapsed since the beginning of the shock.
If an electric bell is included in the circuit, attention
may be drawn to the fact tliat the pendulum requires
re-setting ; but it would be more satisfactory if the
record were made, as in Professor Marvin's seismo-
scope, on a revolving drum, the rate of vihich is not
interfered with by any but a very strong shock.

On account of the delicacy of Dr. Agamennone's
seismoscope, it is necessary to exercise some care in
the choice of a site. It should be placed at least in a
room on the ground floor, but better still in a cellar at
some distance from a frequented street. The most
satisfactory foundation would be one of stone- sunk in
the ground below and entirely disconnected from the
cellar floor. It should also be covered by a glass shade,
in order to protect it from currents of air or other
accidents.

Photograph of the Svirv.

October 22nd. 1905.

The accompanying photograph was taken with an
ordinary 4|-inch astronomical refractor telescope. It
is enlarged three diameters from the original negative,
which was obtained with a power of 40 on the telescope.
A yellow isochromatic screen was used, and the ex-
posure rirodth second on a Cadett lantern plate. The
photograph shows the large group of spots (which was
visible to the naked eye in October) nearing the sun's
western limb, and another large spot surrounded by
faculee just coming into sight on the eastern limb. The
photograph was taken by Mr. E. W. Barlow, F.R.A.S.,
of Bournemouth.

298

KNOWLEDGE & SCIENTIFIC NEWS.

[Decembkr, 1905.

The Venom of Spiders.

Bv C. AiNswoKTii Mitchell, B.A. (Oxon.), l-M.C.

Spiders have gained an evil and Irequently undeserved
reputation as venomous enemies of man, and certain
species are still regarded Ijy the natives in some parts
ot Africa with as much horror as poisonous snakes.

We find numerous references in ancient and media;-
val writers, i.^., in .Vristotle's Natural History, to tlie
deadly effects caused by the bite of spiders, and the
facts eventually became so exaggerated :md distorted,
that m;my writers in the last century went lo the other
extreme and ridiculed the idea of any spider producing
injurious results in m;m.

It is only within the last two or three years that the
question has been investigated by scientific methods,
and that we have been able to form an opinion as to
what amount of truth there was in the old conflicting
accounts that have come down to us.

Leeuwenhoek appears to have been the tirst to
give an exact description of the poison fangs of the
spider, and his account, published in the Transactions
of the Roval S(x:iety for 1 70J (\'ol XXll.. p. 867),
opens in the fi>llowing quaint terms : — " I have often
heard speak of the Sting of a Spider ;md that with the
same he is able to kill a Toad, but having^ never learned
whereabout this Sting grew, I fancied it in the Tail
as it happens in most l'"lying In.sects."

He then goes on to descrilje how a frog bitten by a
spider died within an hour, whereas a second frog
bitten by another spider was not affected in tlie
slightest degree. In explanation of this, he suggests :
" Now 'tis possible thai the .Stingnng of Spiders in hot-
ter Countries may be more pernicii>us than in our
Climate ; 'tis also possible ihat this Spider might have
spent his I'oyson lately by wounding another Spider
or any other Creature." Professor Robert's investi-
gations (infra), doubtless supply the true explanation
of the difference, which was probably that the spiders
belonged to different species.

In a later volume of the Transactions (17:26;, there is
a letter fri>m a Dr. Uobie in New England, giving an
account of the serious illness of a man who had been
bitten in the leg by a small, bhick spider, but was bet-
ter after .14 hours.

All llie early Italian scientific writers contain ac-
counts of cases that had come under their observa-
tion. Dr. Silvio Boccone {Miistn di Fisica, Kigj)
descril>cs numerous instances where illness had l)ecn
caused through the bite of the malmignatte in Corsica.
I-'ontana, writing in 1781 on viper poison, mentions
that the bite of a certain kind of spider might be fatal;
and Dr. Luigi Toti gives a full description of the
symptrjms f>f 17 cases that he had himself altended
prior to 1794. (Jf these 15 recovered after a few days,
one was only saved with difficulty, and one died. 'Hie
effects are de.scribed as being exactly similar to those
caused by tltc bite of a \iper. He himself was bitten
by four of the little m.ilmigmilles, which had just been
hatched. There was some inflammation in the \icinily
of the bites but no general symptoms.

Cauro (18,^.^), confirmed Toti's statement as to the
cfferls f>f the bile of the malmignatte resembling those
pro<lurefl by viper venom, lie st.iird thai the natives
of Corsica used a .secret remedy, whii-h he found lo
consist of a mixture of opium and camphor, and to be
very cfTective.

The spider to which all these Italian writers refer is
the Liitlirodectes ircdaimgiiltatus, popularly known :is
the malmignatte. It is about a third of an inch in size,
and is characterised by the red spots on its Ijl.ick body.
.Vnother liuropean spider belonging to the same family
is the Lathrodcctes conglobatm, which is found in Greece.
1 1 is smaller than the malmignatte and has white spots
instead of red. The Russian species (/-. ercbits), known
as the kara-kurte {black wolf), is common in South
Russia and Turkestan, where it is a great object of
dread. It is jet black, and without any spots.

Species of spiders lx;longing lo the same family are
also found in .-Vmerica (/,. nitii/tins), and in Australia
(Z. icclw. " Ktiti/in," and L. Ihiscllii), all of which arc
reported to produce symptoms similar to those tvuised
by the bile of the Kuropean and Asiiitic species. Both
the .Australian species have red spots on a black
ground.

.\ccording to X'inson (Araiietdcs da lies dc la Reunion
el Madagascar, 1863), the natives of Madagascar are in
deadly terror of Latlirodectcs mcnavodi, which re-
sembles the Italian malmignatte in size and appear-
ance, but have not the slightest fear of an allied black
species. Tliis is cited by Dr. Laboulbene {Diet, des
Sciiinfs Medicates) as a proof of the great exagi^era-
tion of the effects of the malmignalte Ijilc, and ho at-
tributes the fear of the natives solely lo ilic more
ferocious aspect of L. mcnavodi. The answer to this
contention is supplied bv Dr. Koberts results.

W'alckenau, in 1837, made some of the largest
spilers lo lie found near Paris bile him, and never ex-
perienced the slightest ill effects. Similar experiments
were made alx)ul the same time by Duges in the South
of I'rance. but the most serious result was a slight
inf!ammati()n.

Blackwall, the great authority on British spiders,
published the results of his experiments in the Trans-
aeliniis oj I lie Linncan Society for 1855 (\'ol. XXI.. p. 31).
He found that no ill effects were produced up<in himself
by the bite of various spiders, including the garden
sjjider (Araiiea diadeniata), and that e\en insects were
not affected by the venom injected by the fangs of the
spiders. He asserted that " the serious and sometimes
fatal consequences which have been attributed to the
bile of the malmignalte must he regarded as jimusing
fictions in the nalunil history of the Araneidca."

The l'"rench naturalist, Dufour (1864), also came to
the conclusifOT that tin- danger of ihe bite of the spider
was to a large extent imaginary.

ITie question re.maineil in this st;ile of uncertainty
ui.til, in 1901, Dr. Robert Robert published an ex-
cellent monograph dealing will) the whole subject. He
obtained recent data f>f cases of bites, and did an im-
mense amount of experimjntal work with spiders of
different species, notably the Russian kara-kurte
(L. erebus). Detailed reports were sent lo him of 22
cases admitted to Ihe hospit.ils in the Chersonese dur-
ing 1888. In each instance the bite had fell like m bee
sting, and there was usually no swelling around the
place, but sf>on violent pains were felt in the limbs, and
this W'.-Ls succeetled by difficulty in breathing and cold
perspirali(4is, both the heart and central nervous
system usu.-illy being affected. Recovery was generally
complete after five days.

Dr. Robert made extracts from Ihe crushed fresh or
dried Ixxlies of these spiders, by means of a dilute solu-
tion of salt, and thus obtained solutions that were ex-
tri-melv poisonous, prfwlucing .'ill the symptoms .atlri-
buted to Ihe bites.

The poison was not cr)nfined lo the glrinds, for ox-

December, 1905.J

KNOWLEDGE & SCIENTIFIC NEWS.

299

tracts from the leg's or the abdomen proved just as
venomous as those made from the chephalo-thorax.
New-born spiders were more venomous than adults,
and the cocoons and eggs more venomous still.

I^xtracts from the dreaded tarantula were found to
be quite innocuous, and this was also the case with
all the other families of spiders examined, with the ex-
ception of the common garden spider {Aranea diademata
[Epeira diadcma]), which yielded extracts producing
very similar toxic effects. Both caused paralysis of the
respiratory system and heart, accelerated the coagula-
tion of the blood, and had a, strong solvent (haemolytic,
action upon the red blood corpuscles.

The fact that all parts of these spiders were poison-
ous is analogous tO' what has been observed in the case
of snake venom, which is not confined tO' the poison
glands alone, for it has been proved that the blood of
poisonous snakes is also venoi7ious.

Dr. Robert also confirmed Toti's statement that the
venom is harmless when swallowed, and this is another
point in which it resembles snake venom.

He further succeeded in rendering animals immune
against the venom by inoculating them with gradualh
increasing doses, and their immunised serum conferred
protection on other animals.

Both the lathrodectes poison and the poison of the
garden spider were destroyed by heating them at a
comparatively low temperature, and bv the addition of
alcohol, but the former was somewhat more stable than
the latter.

Dr. Kobert concluded that both were of the nature
ol " toxalbumins," i.e., substances resembling white of
egg in chemical composition, but possessing toxic
powers.

Many poisons, however, including snake venom,
which were formerly regarded as toxalbumins, have
been found when properly purified to be free from
albuminous substances, and doubtless this will be
found to be also the case with spider venom.
(To be continued .)

Consvimption of Tobacco.

In the Department of Commerce of the L'nited States
some statistics have been drawn up regarding the con-
sumption of tobacco during recent vears per head of
population in different countries. The following are
the results : —

Belgium

United States

2,817 grammes.
• 2,389

Germanv

I , s6o

Austria
Canada

1,370
I '-43

Australia

I -175

Hungary
France

I ,og8
980

United Kingdom ...

88s

Russia

Italy

This is almost in the inverse

499
■ 476
order of the

amount of

taxation on tobacco.

Royal Institution. — A Christmas Course of Lectures,
adapted to a juvenile auditory, will be delivered at the Royal
Institution by Professor Herbert Hall Turner, D.Sc, F.R.S.,
on •'Astronomy." The dates of the Lectures are December
2S, 30, 1905, January 2, 4, 6, and 9, 1906, at three o'clock.

CORRESPONDENCE.

To THK KniToKs III- " Knowledge."
Gentlemen, — In the three accounts of the recent eclipse
published in " Knowledge" last month, there are consider-
able discrepancies as regards the position of the two groups
of prominences. It is with extreme reluctance that I venture
to differ from so eminent an observer as M. Moye. But my
observations, aided by a telescope, were made very carefully,
and I saw no prominence, much less a group, in the southern
hemisphere. I send a diagram which shows outside the circle
twelve prominences marked at the telescope. One is double-
stemmed, and one is floating. Within the circle I have
marked those shown in Fr. Cortie's six photographs, done at

foivit

the same time and place. The agreement is substantially
exact. In the N.-E. quadrant, No. 5 was of very great height.
Though it appeared the first, it is visible in the last of the
photographs, taken at the very end of totality. On both
sides of No. 5 there is a long blur of light in the first
photograph, like the elevation of that length of the sierra.
This was not noticeable in the telescope, probably owing to
the very pale tint of the chromosphere and prominences.

My eye-piece was divided by spider threads into quadrants,
and the north point approximately fixed by running sunspots
along the horizontal wire.

Yours faithfully,

ArorsTiN Moreord.
The Friary, Saltash, Cornwall,
November 8, 1905.
[In our article in the October number occurs the sentence, " Photo-
graphs alone can give us the true position and dimensions of the
prominences," and these eye sketches, valuable as they are in
many respects, must give way before the incontrovertible evidence
of the photographic plate. — Ed]

Answers to Correspondents.

tiamina. The white-hot part of a coal fire is at a temperature
of over 2300 Fahrenheit, though in an ordinary domestic fire
it seldom attains a real white heat. .-\ dull red- heat is about
1200'^ F.

Rev. M. McLean. This was the aurora borealis, described on
p. 293. It is very rarely seen so distinctly in England.

300

KNOWLEDGE & SCIENTIFIC NEWS.

[December, 1905.

PhotogrsLphy

Pure and Applied.

By Chaf.man Jones, F.I.C, F.C.S., &c.

Distortion with Focal-Plane Shutters. — It has often
been pointed out that an exposure made by passing a
slit of>ening over the face of the sensitive plate must
lead to a distorted image of a moving object, because
the various strips of the object corresponding to the
slit opening are photographed consecutively as the ob-
ject moves. ThLs is so obviously the case that it is
surprising to find the statement met with answers to
the effect that if distortion exists it is negligible because
it is rarely discernible. Whether or not distortion is
visible must depend very largely upon the eye of the
person who looks for it, and upon the character of the
object distorted. A critically-trained eye can see what
ordinary observers never will be able to see, and there
are some distortions that cannot be detected unless the
object, or an undistorted image of it, is available for
comparison. A short, broad person, for example, may
be improved in appearance by having his height in-
creased or his breadth diminished by twenty per cent.

Some excellent examples of distortion with focal-
plane shutters will be found in the current volume of
the "British Journal of Photography" at page 807 et seq.
Here may be seen motor cars all out of shape, and
photographs of a rotating white strip or lath which do
not suggest the object photographed at all. .At page
858, Mr. C. Welborne Piper gives two photographs of
a riding bicyclist. In one the man is slight and the
wheel-base of his machine short, in the other the man
is stout and the wheel-base long, and the wheels are
distorted in both. It must not be concluded from these
examples that focal-plane shutters are useless instru-
ments, but rather that they should always be avoided
when a shutter at the lens diaphragm, or as near to it
as possible, will do the work. It is certainly true that
with a focal-plane shutter the lens acts with practically
its full aperture all the time, but the advantage of this
has been very much over-rated. Many who lay .so
much stress on it probably never knew the rate of
movement or the equivalent exposure given by any of
their shutters in any of their exposures. A record of a
movement that requires an exposure of less than the
two hundredth or three hundredth of a second can often
be obtained only by means of a focal-plane shutter.
The resulting distorted image may l)c sufficient record
as it stands, or it may be possible to eliminate the dis-
tortion by redrawing it, if the constants of the shutter
are known.

Is Development a Reversible Reaction? — In the October
number of this journal I referred to a paper on this
subject by Mr. S. H. Shcppard, published in the
Chemical .Society's Journal for August, and remarked
that in using the word " reversible " the author does
not appear to consider the difference between de\elop-
able and non-developable silver bromide. I said " the
silver bromide is reduced by the developer because it is
in the developable condition, undevelopable silver
bromide not being reduced under the same conditions.
When the reaction is reversed, the resulting silver
bromide would, I suppose, not be likely to be in the
developable state." In answer to this Mr. Sheppard
writes as follows. —

" In the October issue of your journal, Mr. Chapman joncs, in
referring to a paper of mine on the reversibility of photographic

development (Journ. Chem. Sov. — Sept. 1905) criticises the applica-
tion of the term ' reversible ' to this reaction on the ground that
the silver bromide reduced by tlie developer is in a ' developable'
condition, due to the action of light, whilst that reformed by the
reverse reaction to development is presumably not so. The phrase
■ developable silver bromide ' can hardly l)e said to express any
exact conception, since with a reduciiv.; agent of sufficient potential
silver bromide, either alone or emulsitied, can be reduced to silver
without any previous exposure. If. however, we take it to mean in
this case, reduction by the ordinarv developing agents of practice,
Mr. Jones' criticism still fails to hold, ;is the silver bromide
reformed by the re\erte ' bleaching ' action is • developable '
forthwith and without any preliminary exposure to light, a fact in
agreement with photographic practice in intensification by
redevelopment (r/. Messrs. C. W. Piper and D. J. Carnegie,
Amateur Photograj'hcr ior June, 1905). Thereat point at issue is,
of course, the nature of the so-called ' latent image ' formed by
light, but this question, however interesting, cannot be dealt with
in a brief letter."

It has long been known that the reaction between
ferrous t)xalate and silver bromide is rcxersible. For
more than twenty years practical advantage has been
taken of this fact in the use of ferric oxalate to thin or
dissolve away a part of the silver from a negative that
is too dense. It may be objected that no alkaline
bromide is added in this case, but that does not affect
the essence of the reaction. Mr. Shcppard has deter-
mined the conditions of equilibrium, including the
effects of alkaline bromide and dilution. In doing this
he claims to have " shown experimentally that develop-
ment is a reversible chemical reaction " (quoted from
his abstract of his paper in the Proceedings of the
Chemical .Society).

I cannot see that he has done anything towards
proving development to be a reversible reaction. De-
velopment and simple reduction of the silver salt must
l>e distinguished. A reagent that will reduce silver
bromide will not, therefore, develop an image. .Silver
bromide exists in the developable and the non-dovclop-
able conditions, although it is reducible to the metal in
both conditions. Mr. .Sheppard says that " ' de\elop-
ablc silver bromide ' can hardly be said to express any
exact conception," but this ha.s nothing to do with the
matter. We are dealing not with conceptions hut with
facts. The difference between developable and non-
developable silver bromide is a fact, it is more than the
chief corner stone of photography, it is the very fotnida-
tion of it, and conceptions, exact or otherwise, do not
affect it. It is just in this that the difference exists
between simple reduction from a chemical point of
view and development from a photographic point of
view, and so far as I can see Mr. .She])i)ard h;is not
gone beyond the simple chemistry.

But suppose for a moment that Mr. .Shcppard h.id
pro\ed development with ferrous oxalate to be a re-
\ersible change, he would not have proved development
in general to be reversible, because ferrous oxalate is
a developer by itself, and, as a matter of practical fact,
is now very rarely u.sed. There arc many developers of
quite a different character (chemically considered) and,
perhaps, different in their action as develojx'rs.
Probabl)* the most simple f)f these is hydroquinone (or
quinol). Of this Mr. Sheppard him.self says " this re-
verse reaction is largely nullified by the presence of
alkali and alkali sulphite, alw;iys used with organic
developers, as the.se substances alone or mixed react
with the quinone, reducing it to quinol." So there
seems to be a difficulty here, even with so simple a
substance as hydroquinone, in proving dcvelopnuwit to
1h; reversible — a difficulty th.-it Mr. Sh<pp;ird h.is not
overcome. And even if development with both ferrous
oxalate and hydroquinone were proved to be reversible
changes, it would not necessarily follow that develop-

December, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

301

mcnt with other reagents is also reversible, as hydro-
quinone has marked peculiarities.

Mr. Sheppard's reference to the use of the word
"development" by Messrs. C. W. Piper and D. J.
Carnegie is beside the mark. This word is in common
use and has many applications. We talk of " de-
veloping " a carbon print when we merely wash away
the soluble gelatine from it with water; we " develop
a platinum print when we bring about a simple chemi-
cal reaction; an essay writer " develops " his subject;
and an athlete " develops " his muscles. In the " re-
development " referred to there does not appear to be
any distinction between developable and non-develop-
able silver salt — it seems to be rather a simple case of
removing the halogen from its silver compound.

A yew Tripod. — The limitations of the ordinary
tripod are all too well known bv those whose work re-
quires the camera to be supported in other than an
approximately horizontal position or in places where
the ground is steep and irregular. These difficulties
are practically overcome in Butler's " Swingcam "
camera stand. The wonderful adjustability of this
stand is obtained by attaching each leg to the tripod
top by means of side links and a swivel block. In re-
placing a single movement by three separate move-
ments a loss of rigidity might be expected, but the ad-
justing screws so clamp the whole of the moveable
parts together that the maker claims an increase rather
than a loss of stability. Further conveniences in con-
nection with the stand are extending bars which will
raise its height to over seven feet, and swivel points to
the legs, so that the points may be fixed vertically to
obviate slipping when the legs are unduly splayed out.
These points may even be bent up and converted into
hooks, so that, for example, one leg may be secured to
a convenient object above the camera, such as the
branch of a tree. It is impossible to describe all the
ways in which the stand may be u.sed.

The Thornton-Pickard Company send us tlie list of winners of
the /^loo Competition for pictures taken with their cameras. The
numerous prizes range from £\o to £1.

ASTRONOMICAL.

By Charles P. Butler, A.R.C.Sc. (Lond.), F.R.P.S.

The Newly Mounted Three-Foot
Crossley Reflector.

This fine instrument, which was first erected at the Lick
Observatory in 1895, has been almost entirely remodelled
according to designs of the astronomers there. Although
much excellent work was done with it in its original condition,
it was found that many details were unsatisfactory for the
prosecution of the delicate investigations which the late
Director Keeler had proposed to devote its great light-
gathering power. From the extremely promising records
obtained it was thought that the great value of its excellent
parabolic mirror in astronomical photography emphasised the
desirability of supplying it with a more rigid and efficient
mounting than the one comprised in the original bequest.
This was authorised by the Board of Regents in 1902, and

after much consideration it was decided to adopt the form
shown in the illustration. Tiie heavy parts of the mounting
were built by the Fulton Engine Works of Los Angeles, while
the driving clock, slow motions, guiding mechanism, and all
small parts were constructed in the Lick Observatory repair-
ing shops.

The polar axis is of heavy boiler steel, furnished with steel
jackets shrunk on to form the bearing surfaces. The declina-
tion' axis is a heavy shaft of solid steel passing through the
centre of the polar axis. One end carries the tube of the tele-
scope, the other the usual counter-balancing weights.

The tube consists of a cubical central section of castings,
with cylindrical sections above and below the cube to carry
the eyepiece and large mirror respectively. The upper end
section can be rotated for adjustments in position angle.
The total weight of the moving parts is about 6 tons, and
although somewhat cumbersome has the important advan-
tage that it allows of passing the meridian in all positions
without reversal.

As the driving mechanism had to be very delicate, the
driving sector was made large, with radius of eight feet, the
worm having a pitch of one-tenth of an inch, and as a com-
plete driving wheel of this size would have been too unwieldy,
two sectors were provided, so that one could always be ready
for gearing up as soon as the other was running out. Each
sector will run for 66 minutes.

In connection with the optical arrangements important
modifications have been introduced. The ordinary method with
Newtonian reflectors of throwing the image out at the side of
the tube by a plane mirror placed diagonally has been dis-
carded, and the plate holder fixed in the centre of the tube so
that the plate is in the direct optical axis of the large parabolic
mirror, and of course it cuts off in this position no more, or
probably less, light than did the original diagonal mirror.

The adoption of this system then rendered it necessary to
bring the screw adjustments of the plate holder to the side of
the tube, and this has been done along one of the thin plates
which hold the plate carrier. By means of a small reflecting
prism the guiding star at the side of the photographic plate is
also viewed by a subsidiary telescope at the side of the tube.

On account of the old difficulties special precautions were
taken in designing the mirror cell and supports, and it is very
satisfactory to find that Professor Perrine reports that the
whole is very satisfactory after several months of use. The focus
of the instrument can be determined easily to 0-005 inch, and
it does not appear to change greatly with variations of tem-
perature. No change of focus has yet been detected in a
range of less than 10 ' F. Evidence of the great efficiency of
the instrument is afforded by the splendid success achieved by
Professor Perrine in his recent important discoveries of the
VI. and VII. satellites of Jupiter in the earlier part of the
present year.

302

KNOWLEDGE & SCIENTIFIC NEWS.

[December, 1905.

By C. AiN~

CHEMICAL.

MucHi:!.!.. i-!.A.

IM.C.

Coffees without Caffeine.

The alkaloid caffeine, to which tea and coffee owe their
stimulating property, crystallises in glistening white needles,
which melt at a relatively high temperature, and can be
sublimed unchanged. Tea contains some 3 or 4 per cent, of
this alkaloid, and coffee about 1' per cent., while it is also
present in mate, or Paraguay tea, and guarana, a beverage
prepared by the natives of Brazil from the seeds of PauUinia
sorbilis. M. G. Hertrand discovered four years ago that a
species of coffee, Cotfcii humhlotiaiui. growing in Madagascar,
was quite free from caffeine, although containing a bitter
principle to which he gave the name cii/aiiutiinc. Since then
he has found several other species of the coffee plant to con-
tain only a small proportion of caffeine, and quite recently
has e.xamined three new species which were absolutelv free
from the alkaloid, but contained a bitter substance analogous
to that occurring in C. Iiitmhlutiaiia. All of these coffee plants
devoid of caffeine grow either in Madagascar or the neigh-
bouring islands, and are not found on the African continent.
In order to determine whether the soil or climate had any
immediate influence upon the development of caffeine, experi-
ments were made with the ordinary coffee plant. C. arabica,
but the plants grown in Madagascar invariably yielded the
normal proportion of alk.aloid.

The Cultivation of Plants on Radio-
Active Soil.

Some extremely interesting experiments have been made
by M. A. v. Poehl to determine the effect of cultivating
pharmaceutical plants at Tsarkoie-Selo, near St. Petersburg.
where the soil contains argillaceous schists, which, as is well
known, are radioactive. The plants were examined after a
year, and were found to contain radium, which, however, was
only present in the roots and stalks, and never in the flowers.

The Utilisation of Natural Gas.

Natural gas is found in constant association with petro-
leum, but has hitherto been put to but little use, at all events
in Kurope. In Boryslaw. for instance, it is particularly plenti-
ful, but is for the most part allowed to escape into tne air,
with the exception of the small quantity used for heating the
vessels in which the crude petroleum is distilled. In America,
however, it is used as the source of a gas black for printing
ink, for the illumination of houses, to which it is supplied
under a pressure of half an atmosphere, and as fuel for glass-
works and other factories which have been built near the
sources of supply. In this country the natural gas discovered
at Heathfield, in Sussex, is collected atjd used for lighting the
bouses. The possibility of many new applications of natural
gas is suggested by the fact that Herr NVolski has taken out
a patent in Austria for its liquefaction, and that the process
has been found a success in the Carpathian oil fields. The
liquefied gas begins to distil at about 106" C, and the first
fraction consists in the main of the hydrocarbon methane.
The vapour tension of the liquid is relatively very small, and
the product can therefore be safely kept or transported in
ordinary soda-water syphons. It seems likely to have a
great future before it for such purposes as lighting isolated
houses and driving small gas-engines and motors, whilst being
a bye-product of the petroleum industry its cost will be much
less than that of ordinary coal gas.

A New Ferment.

There are many species of veast, but until recently none
was known th.at was capable of'^ resisting a high temperature.
Messrs. Johnson and Hare, however, have separated from
eucalyptus leaves a new species possessing this characteristic
in a high degree, being able to convert sugar into alcohol at a
temperature of over 105 F., which would be fatal to ordinary
yeasts. At the end of the fermentation the new yeast, to
which has been given the name of Saccluircmyi c Ihcrmunliloniim,
falls to the bottom of the ves-sel in a compact agglutinated mass.
The cells are more oval and rather smaller than those of
the more common saccharomyces, and have several other dis-
tinguishing features. The use of this ferment has been pro

tected by 55 patents in different parts of the world, for its great
commercial value is due to the fact that by its means fer-
mentations can be carried on in tropical countries, where
hitherto this was out of the question. A further advantage is
that it is possible by simply heating the cultivations to destroy
foreign micro-organisms without injuring the yeast. It is so
resistant to heat that it can withstand for a short time a tem-
perature of 1 700 ]■'. Even after the cells have been killed by
being submerged in water at 176' F., the active agent or
enzyme they contain is still capable of producing a weak fer-
mentation.

Sympacthetic Inks.

Sympathetic inks are connnonly regarded as chemical toys,
although the fact that several recent patents for such inks
have been taken out shows that they have practical uses of
commercial value. One of the earliest means of writing in
characters that were nearly invisible until warmed was milk,
the use of which was recommended by Ovid, whilst Pliny
makes mention of various plants whoso juices were suit-
able for the same purpose. Numerous references to secret
inks occur in media;val writings, but we can only make
a guess as to their composition. Brossonius, writing in
a medical treatise in the earlier part of the 17th century, de-
scribes a " magnetic fluid," prepared from " arscniated liver
of sulphur," only visible when looked at " with the eyes of
affection." This appears to have been nothing more than a
solution of lead acetate, the characters being rendered visible
by the action of sulphuretted hydrogen. This lead acetate
ink is described by several other early writers, and notably by
Otto Tachen (iCrxj), who points out that there is nothing mag-
netic or miraculous in its action. It was described as " sym-
pathetic ink " by Le Mort, and the name was afterwards ex-
tended to all preparations suitable for secret writing. The
curious behaviour of salts of cobalt when heated was first de-
scribed by Waiz in 1715. and solutions of one or other of these
have since formed the basis of many of the so-called sympa-
thetic inks. Cobalt chloride, for instance, is pink in tho cry-
stalline condition, but when heated loses water and becomes
blue. Characters written with a solution of this salt are nearly
invisible on white paper, but turn blue with heat, and then
gradually absorb moisture from the .lir becoming pink again,
and practically disappearing. In the case of some other sub-
stances .1 re-agcnt is required to develop the writing. Thus
characters written with gall extract turn black on treatment
with an iron salt ; gold chloride gives purple writing with
tin chloride, and starch gives a blue coloration with iodine.
The last-named ink has long been a favourite with sharpers of
the racecourse, two of whom were last year convicted of the
fraud. A betting paper giving the names of the hor.ses is
written in two kinds of ink, one of which speedily fades away,
while the other gradually appears. The disappearing ink is
often a weak solution of iodine tinged with starch, and the
characters written with this soon fade. I'or the invisible
writing a favourite ink is a solution of silver nitrate, which
darkens imder the influence of light. An ingenious applica-
tion of a sympathetic ink, patented by Kromer, insures the
detection of any tampering with an envelope. Ihc dry con-
stituents of the ink, e.f;., tannin and iron sulphate, are separ-
ated by means of the adhesive gum, so that should steam be
used to open the envelope they come into contact and leave a
stain upon the paper. A sympathetic method might be based
upon the fluorescence of quinine salts imder ultra-violet light,
or of other compounds when exposed to the rays of radium, &c.

GEOLOGICAL.

Hy FiiUAnii A. Mahtin, F.G.S.

"Wash-Outs" in Coal-Seams.

The subject of "w.ish outs" occurring in .some of the middle
coal-measures of South ^■orkshire has bcc;n dealt with by Mr.
I-". F. Middleton, I'.Ci.S., in a paper recently published in the
Quarterly Journal of the Geological Society. He is of (ipinioii
tfiat they occupy tlic sites of winding streams, which mean-
dered through the .illuvial tracts in which the coal-seams were
being formed. This would account for breaks in the con-
tinuity of the deposition of certain seams, but true wash-outs

December,

I905-J

KNOWLEDGE & SCIENTIFIC NEWS.

303

would be those which were attributable to subsequent denuda-
tion of seams as originally formed. In the Eureka seam in
Netherseal Colliery (South Derbyshire Coalfield) the wash-out,
instead of being one broad hollow, consisted of numerous con-
fluent streams, and these united together to form a main
channel, like the head-waters of a drainage system. Mr.
Middleton points out that in the Barnsley seam denudation
has been found over an area 1700 yards in length from east to
west, and in the Parkgate seam (240 yards below) over an area
2600 yards long from north to south. Although the wash-out
in neitiier case was completely crossed, the width, it is thought,
could not be less than 600 yards.

The Genus Glossopteris.

The question of the true affinities of the genus dlnssoftliri.^
at present remains an open one. As a rule, it is classed with
the Filicales, but this classification can only be regarded as a
convenience, and must not be regarded as finite. Minute
organs, elliptical in shape, have been in close association with
Glossoptfi-is Brozi-niana, in specimens from New South Wales,
which Mr. E. A. N. Arber, F.G.S., F.L.S., thinks are not un-
like the sporangia of certain recent and extinct ferns and
cycads. There is, however, no trustworthy evidence as to
their contents. That they may be attributed to this genus is
indicated by the fact that they have never been found except
in the closest association with the scale-leaves of Glossopteris,
whilst some of the scale-fronds show scars of attachment and
fragments of sac-like bodies still apparently in continuity. A
close analogy may perhaps be found, Mr. Arber thinks, in the
micro-sporangia of cycads.

Tertiat-ry Limestone at Belmont Hill.

In reference to the white tertiary limestone from Heme Hill,
to which I recently referred, my attention has been called to
some hard flinty " race " which was found this year at the base
of the cyi'cna Shell-bed (Woolwich series), about 12 feet from
the surface, at Belmont Hill, Blackheath. This has been ana-
lyzed by Mr. H. Dixon Hewitt, for the Geologists' .Association,
with the following result ; —

Calcium carbonate (CaCOj) ....

Magnesium carbonate (MgCO^)

Iron and Aluminium Oxides (ALO3 + Fe203) .

Sand and Clay .......

Combined Water, traces of Alkalis, Phos-
phates, &c. (by difference) ....

947

3-0
0-6

Submerged Coacst- Lines.

At the opening meeting of the Geological Society of London
on November 17, an important paper on " The Coast- Ledges in
the S.W. of Cape Colony " was read by Prof. E. H. L.
Schwartz. Similar coast shelves have there been found
to those which characterise both the European and American
sides of the North Atlantic. The most striking of these re-
markable coast-shelves is said to be the Upland Shelf, extending
from Caledon to Port Elizabeth. It is cut by deep gorges
into narrow ridges or " ruggens," but at a height the level tops
of these ridges can be observed. The surface is in places
covered with superficial deposits, cemented boulder-deposits,
gravels, and sandy clays, hardened at the surface into iron-
stone or freshwater quartzite. Prof. Schwartz considers that
this shelf cannot have been formed as a peneplain, but by
marine denudation. On the 150 to 200 feet plateau there are
deposits with marine shells, and in a depression on its top the
evaporation of rain-water produces a large quantity of salt.
The rock-shelf under the Cape Flats appears also to have
been cut by the sea. The .\gulhas Bank seems to consist of a
succession of ledges, but it is not known whether further
shelves extend beyond its margin. Taking the ledges together,
the continent would appear to have been subject to lifts of
600 or 700 feet, with intermediate halts and setbacks.

Wha-t is the Thirpole ?

We all know Cuvier's Pul^otlitrium, or ''ancient wild beast " of
the Paris basin, but what are we to understand by the name
" Thirpole," to which Dr. W. Martin, of Lincoln's Inn, refers
in the following communication ? It will be seen that he sug-
gests that the two names are of identical origin. He says :
" What is the fish called Thii-polc that is alluded to in the fol-
lowing quotation from Staunford's ' Exposition of the Kinge's

Prerogative ' (edition 1577)? 'So in Bracton's time it was
doubted by the common lawe, whether the King should have
this great fisli called Thivpolc wholly or not. And so like-
wise in Britton's time, as it may appe.ar in his book fo. 27,
which now this statute hath made clear and without question.'
I cannot find any reference to this fish either in Bracton, in
Britton, nor in the statute to which allusion is made. Possibly
Thirpole was a word newly coined by Staunford from the
Greek words tf-np, a monster, and iraXaios, ancient, venerable,
and was meant to be equivalent to 'that leviathan,' about
which so much was heard, but which was never seen. I may
mention that whales, sturgeons, and possibly porpoises, were
considered, when caught within seas that were part of the
realm, the property of the sovereign or his consort, and were
consequently called ' Koyal Fish.' "

ORNITHOLOGICAL.

By W. P. PvcRAFT, A.L.S., F.Z.S., M.B.O.U., &c.
The Dura-tion of Life Among Birds.

When we consider the great numbers of those who are
interested in birds, it is strange that there should have been
so little recorded as to the age to which birds live.

Parrots are proverbially long-lived, and most of us are
familiar with the story of the venerable bird which Humboldt
met with in South America. Though voluble enough none
could understand it, as it spoke the language of a tribe of
Indians— Atures— which had long become extinct.

Weissman mentions a white-headed vulture which died in
the Zoological Gardens at Vienna in 1S24 after 118 years of
captivity. Ravens are said to have lived 100 years in con-
finement, while canaries and linnets may live from to to iS
years.

The latest contribution to this subject will_be found in an
extremely interesting article by Lady Ingrain in the Windsor
Mai^dziiic for November. Herein will be found many curious
and not a few reallv valuable facts, especially with regard to
the question at issue. Thus white birds are generally sup-
posed to be less robust than more normally coloured, yet a
white sparrow whose life history is described in this article
has lived 13 years in confinement, and during this time has
reared no fewer than 12 broods! Though this bird is still in
good health it appears, however, to be showing signs of age.

Hoopoe in Inverness=shire.

The FiiU, November 11, records the fact that a hoopoe
was shot at Onich, Inverness-shire, during the first week in
November. It had, unfortunately, been hovering about the
neighbourhood for some days, and had been kept under
observation by one or two well-wishers, only to fall a victim
at last.

Breeding of Common Kite in Wales.

Owing to the action of the British Ornithologists Club, aided
by the kindly cooperation of Earl Cawdor and Dr. Salter, the
last remnant of the kites in Wales were this year enabled to
rear their young unmolested ; two pairs succeeding in bring-
ing off two young each. It is believed that no young kites
have been reared in Wales for at least 10 years past.

Breeding of the Bower Bird in
Confinement.

Mr. Reginald Phillipps is to be congratulated in that the
Regent bower-birds (Sericulus mdinus) in his aviaries have
this year succeeded in rearing young. Tw6 birds were
hatched, the first on August 6, the other two days ater; by
Au-ust 22 both birds had left the nest, having, it is to be noted,
well-developed wings, but scantily covered bodies. Lnfortu-
nately one of these birds was killed during September, ap-
parently by swallowing the shoots of an elder tree ; but the
other bird is now full grown and hardly distinguishable from
the female. The period of incubation appears to be nineteen
or twenty days. This is the first record, we believe, of the
breeding of these birds in confinement.

304

KNOWLEDGE & SCIENTIFIC NEWS.

[December, 1905.

A New British Shrike.

At the meeting of the British Ornithologists Club held on
October 18, Mr. M. J. NicoU exhibited a fine male adult speci-
men of Latins iiiibiius, which had been killed at Woodchurch,
Kent, on July 11, 1905.

BlaLck eared Chat in Sussex.

At the meeting of the Ornithologists Club just referred to,
Mr. M. NicoU also exhibited a black-eared chat {SaxUola
sfapazimi), which had been killed at Pett, in Sussex, on Sep-
tember 9. This bird, Mr. Nicoll pointed out, belonged to the
Eastern form of the species, having the underside of the
wing and the axillaries jet black. The two previous occur-
rences of the black-eared chat in these islands were both of
the Western form (Sa-xicoln catarimc).

Aquatic Warbler in Sussex.

Mr. Nicoll also exhibited at this meeting an aquatic warbler
(Acrociphalus itiiuiilicus) which he had shot at Kye, Sussex, on
August iS of this year, and reported that during the day he
saw about half-a-dozen of these birds in one large reed-bed.

Aquatic Warbler in Hampshire.

Mr. H. F. Witherby exhibited at the meeting of the Club
just referred to, an acjuatic warbler which had been taken on
St. Catherine's Lighthouse, Isle of Wight, on September 29
last. The bird was an immature female, and made the third
record of this species in the county.

Icterirve Wa.rbler in Hampshire-
Mr. Witherby exhibited, with the a<iuatic warbler, an im-
mature female of the icterine warbler (Hy/yotais icUrina). This
bird had also been taken on St. Catherine's Lighthouse at
the same time as the aquatic warbler, and was the first re-
corded instance of the occurrence of this species in the
county of Hampshire.

^^^^^.^

PHYSICAL.

By .-\li-rel) W. Porter, B.Sc.

Emission of Corpuscles in the Dark.

It is well known that the alkali metals give out negative
corpuscles ii.i-., electrons) when exposed to light, even when
this is of verj' feeble intensity. Thus in the case of sodium or
potassium or their liquid alloy, Mister and Geitel found that
a negative charge was dissipated by the light from a petroleum
lamp; while from the still more electro-positive metal rubidium
negative electricity could be discharged by the light from a
glass rod just heated to redness. The order of the metals for
this effect is the same as the order in Volta's series for contact
electricity.

Professor J. J. Thomson has now shown that, with the
metals mentioned, there is a small emission of corpuscles,
even when all external light is excluded. .An electroscope is
placed in a bulb, which can be very highly exhausted by means
of charcoal cooled to a ver>- low temperature — the brilliant
device of Sir James Dewar for very rapidly producing exceed-
ingly high vacua. Clean rubidium or K-Na alloy is placed
below the gold leaves, and the metal is earthed. The whole
is placed in a light-tight case, no light being admitted except
a momentary illumination through a red glass window for the
purpose of reading the deflection of the leaves. Even this
momentary illumination produced a slight leak, which can,
however, be separated from the true leak by the fact that the
latter is proportional to the interval between the readings,
whereas the former is independent of this interval.

When the leaves of the electroscope were charged with
po.>tlive electrification, there was always, even in the dark, a
small leak of electricity, while there was no leak when the
leaves were nei^ativdy charged. The leak apparent in the
former case is attributed to negative corpuscles leaving the
alkaline metal and settling on the leaves. This is proved by
the fact that when the bulb is placed in a transverse magnetic
field the leak stops.

The presence of a minute quantity of hydrogen in the bulb
has an extraordinary influence in increasing the leak ; in some

cases after the admission of the hydrogen, it was made
ten times as great. This increase rapidly died away, but was
renewed on admitting a fresh supply of hydrogen. No increase
was produced on admitting carbon dioxide.

Final Disintegration Product of Radium.

Rutherford considers that the ultimate residue alter all the
charged particles have been emitted by radium is lead. The
atomic weight of radium is 225 ; five .Alpha particles at least
are known to be expelled during the successive changes that
take place. If each of these is an atom of helium of mass 4
the residue must have an atomic weight of 205, which is ex-
ceedingly close to the atomic weight of lead. In support of
this conjecture, he cites the fact that in all radio-active
minerals lead is present, and its amount is roughly propor-
tional to the helium present. This would be the case if both
of them are disintegration products.

ZOOLOGICAL.

liy K. LVUEKKUR.

Son\e Fossil R.eptiles.

Since our last column of Notes was written three papers of
more than usual interest have appeared on extinct reptiles.
In the first of these Mr. C. W. Gilmore has published a brief
illustrated account of the complete skeleton of that most mar-
vellous of all fossil reptiles, the great horned dinosaur (Triccr-
atops prorsus) of the Cretaceous strata of Wyoming. In addi-
tion to its horns, the most extraordinary feature about this
creature is the huge size of its head, with its great frill-like
collar extending backwards well on to the shoulders. This is
shown by the fact that while the length of the entire skeleton
is 19 feet 8 inches, that of the head is no less than 6 feet, or
nearly one-third the total dimension. In this respect rnViT-
atops presents a strange contrast to the Diplodociis skeleton in
the British Museum, in which the head is only about one-
eightieth of the total length. Nevertheless, the horned monster
was no better off in the matter of brains than its small-headed
cousin.

In the second of the two memoirs Mr. L. Dollo, of the
Brussels Museum, gives us the results of his investigations on
the footprints of the iguanodon, based on specimens from the
Wealden strata of Hastings and its neighbourhood. From a
careful study of these tracks the author is enabled to tell us
the approximate postures assumed by this giant dinosaur
when running, walking, and at rest.

In the third and last paper Mr. Gilmore confirms the dis-
covery that the so-called toothless American fish-lizard, Dapta-
nodoii, really possessed a few rudimentary teeth, thus bringing
it into close relationship with Oplluiliiiosnurns of the Englisli
Oolites.

The Deafness of Fishes.

Despite the fact that carp in a pond will come up to be fed
at the sound of a bell, a learned German professor has arrived
at the conclusion that fishes of all kinds arc in all probability
stone-deaf. This conclusion, startling as it may seem, is
largely based on the fact that these creatures lack a certain
structure in their auditory organs which the professor regards
as absolutely essential to the function of hearing. Such vibra-
tions in water as fishes are capable of perceiving are conse-
quently believed to be transmitted by a sense compatible with
our own sense of touch or feeling.

South America, Africa. at.nd Austratlia.

In his recent presidential address to the Zoological Section
of the British .Association Mr. G. A. Boulenger, from the
evidence of freshwater fishes, is disinclined to believe in a
landcoTinection during late geological times between South
A.nerici and Africa. I'rofessor W. B. Scott, from the study of
certain fossil mammals, is, on the other hand, convinced that
such a connection did exist ; while the examination of some
supposed f(}ssil marsupials from Patagonia leads Mr. W. J.
Sinclair (who, like Prof. Scott, belongs to Princeton Univer-
sity) to be equally confident as to the existence of a similar

December, 1905.

KNOWLEDGE & SCIENTIFIC NEWS.

305

bridge between South America and Australia. With such
diversity of views among " doctors " it is a little difficult for
the amateur to know which lead to follow; and it is therefore
satisfactory that the subject is not one involving any vital or
pressing issues.

Ancestry of the Dog.

From deposits in Russia belonging to the polished stone-age
Dr. T. Studer has recently described the sUeleton of a large
kind of dog closely allied to the domesticated species. This
dog, which it is proposed to call Cnnis ponlintini, is believed to
have been originally wild but subsequently domesticated by
early man. In general characters it comes very close to the
Australian dingo. By crossing between this species and the
wolf Dr. Studer believes that other extinct species or races of
dogs have arisen, and from these in turn have been developed
the mastiffs on the one hand and the deerhounds on the other ;
and it is also presumed that the sheepdogs and hounds trace
their origin directly to the same ancestral form. On the other
hand terriers and Pomeranians are believed to have sprung
from a totally different extinct stock. Dr. Studer may be per-
fectly right in these respects, but he has yet to prove that Canis
poiitiatini is a truly wild form, and not a domesticated deriva-
tive from the wolf.

A Mysterious R^eptile-

In the Transactions of the New Zealand Institute a digni-
tary of the Church records some interesting information with
regard to an unknown reptile supposed to inhabit the Waoku
Plateau. Legends are rife as to the existence of this creature,
which is said to be amphibious ; and about five-and-thirty
years ago an example, in a decomposing condition, is reported
to have been seen by a European. A second specimen, about
18 inches long and of a yellow colour, is said to have been
observed by a lake about fifty years ago. The suggestion has been
made that the creature is a salamander ; but, from the distri-
bution of that group, this is highly improbable. If it be any-
thing more than a myth, it is far more likely to be an amphi-
bious representative of that strange reptile the New Zealand
tuatera, the sole known survivor of an extinct order.

Tsetse Fly.

All that is known concerning the geographical distribution
of those terrible African pests, the tsetse flies, will be found in
a map accompanying tlie latest issue of the Royal Society's
reports on the sleeping-sickness.

REVIEWS OF BOOKS.

The Microtomists' Vade-Mecum, by Arthur BoUes Lee.
Sixth edition, pp. x. and 53S. (J. & A. Churchill, 1905 ;
price 15s. net). — This well-known book was first published in
1885, and the volume before us is the sixth edition, the pre-
vious edition being issued in igoo. This alone would show
that the book is a useful one, but the fact is that to the
worker with the microscope, whether in anatomy, or physio-
logy, or zoology, the book has become indispensable as a work
of reference. It is above all things a book for the serious
worker, but the amateur, if he has the root of the matter in
him, and wishes to understand the methods of preparation of
objects upon which modern microscopical research is now so
largely built, will find it most instructive. To the professional
worker, however, it no longer needs recommendation. It
represents exceptional labour in bringing together so many
methods and formulae, and not less judgment in deciding what
to omit where the mass of material for selection is so great.
The new edition varies from the previous one mainly in the
direction of consolidation and perfecting of the arrangement
of the subject matter. The old chapter on " Staining with
Coal-tar Colours" is now embodied in the chapter on
" Staining " generally. The chapter on " Connective Tissues "
and on " Blood and Glands " appears now as two separate
chapters, and they contain much new matter, having been, in
fact, largely re-written. The chapters dealing with the nervous
system have been re-arranged, and have received especial
attention, with especial reference to new methods. The bulk
of the matter deals, of course, with histological methods for

man and the higher vertebrates, and one might perhaps wish
that the methods for the invertebrata could be slightly
extended. — F.S.S.

Methods in Microscopical Research-Vegetable Histology, by

Abraham P'latters, F.K.M.S. ; pp. x. and 116; 2(j illustrations
in the text and 2Z coloured plates containing 85 figures
(Sherratt and Hughes, 11)05 ; price 21s. net). — Unlike the book
reviewed above, this work is written for the elementary student,
and not for the advanced worker. In fact, the title is some-
what misleading — unintentionally, no doubt — as the elemen-
tary methods in vegetable histology dealt with here can
scarcely be considered as methods of research, as the term is
generally understood, however suitable they may be for teach-
ing a class of beginners their first steps in botanical histological
methods. Mr. Flatters selects some half-dozen well-known
fixing and preservative reagents, and a dozen or so simple
stains, and explains the various processes by which a botanical
specimen can be prepared for section-cutting, either by the
celloidin or paraffin-infiltration methods, cut in the hand-
microtome, stained and mounted. The instructions generally
are based on those carried out by Mr. Flatters' class in the
Manchester Municipal School of Technology, and are clear,
concise, and adequate for their purpose. The accompanying
letter-press is beautifully illustrated, but some of the illus-
trations seem to be rather superfiuous — for example, an illus-
tration of eleven ordinary hollow-ground slides of different
sizes and shapes, or of twelve "rings" of different sizes for
building up deep cells. The plates are devoted to illustrations
of various botanical sections prepared by the above methods,
with brief descriptions. They are beautifully reproduced in
colours, and appear to be for the most part from photo-
micrographs, and, if not differing greatly from the ordinary
botanical slides sold by the better-class opticians, at least
serve to show what similar slides should look like, and have a
considerable educational value as well. The best of these
reproductions of slides is one showing mitotic division in a
longitudinal section of an onion. We are not quite sure
whether the volume under review is published in the ordinary
way, or is an advance copy of a work to be published by sub-
scription, conditional on a minimum of 200 subscribers being
obtained. — F.S.S.

The Uses of British Plants. Books dealing with British
plants are legion, but one treating the subject from a new
point of view is decidedly a novelty. It may be argued that
no new idea is presented ; nevertheless the information brought
together was previously scattered through publications, dating
from the fourth century K.c. up to the present day. The reader
is introduced to many pecuhar views entertained by people of
past ages as to the virtues of our common wild plants from a
medicinal standpoint. The etymology of both English and
Latin names is instructive. Finally, the numerous figures,
illustrating 28S British plants, adds to the value of the book.

Everyday Life Among the Head-hunters ; and other Ex-
periences from East to West. By Dorothy Cator, pp. xiv. and
212; illustrated (London, 1905: Longmans, Green and Co.;
price, 5s. net). — Apart from " experiences" on the West Coast
of Africa and elsewhere, which, although entertaining enough
in their way, are of no very special interest, Mrs. Cator has
given an account of some of the little-known tribes in the in-
terior of the great Malay island which accords to her brightly
written little volume a value far above what can be claimed
for many works of a similar nature. And not only is the author
to be congratulated on having furnished so much information
with regard to these native tribes, but she is entitled to a high
position among Englishwomen who have done credit to their
race and country by their personal prowess and pluck. As
the companion of her husband on several journeys connected
with his official position into the interior of Borneo, Mrs. Cator
hail the opportunity of seeing tribes to whom a European was
previously unknown, and from whom it was a question as to
the kind of reception which would be accorded to the
travellers. Fortunately, all turned out well, and the author is
enabled to bear testimony to the civility with which even the
most truculent of head-hunters receive strangers, and to their
quiet and afiectionate family life when they are not on the
war-path. Gifted with an observant mind, and with the power
of recording her impressions in pleasant and readable language,
the author has, we think, scored a decided success in this book
of travels among the head-hunters of Borneo.

3o6

KNOWLEDGE & SCIENTIFIC NEWS.

[December, 1905.

Magnetic Induction in Iron and other Metals, by Professor J. A.
Ewing (Electrician Publishing Office). — We have received
a copy of the third edition of this classical treatise. It is a
veritable imli: mnum for the electrical engineer, or, indeed, also
for the theoretical physicist. Commencing with the simplest
definitions of magnetic qualities, the author extends the treat-
ment so as to include not only directly magnetic phenomena,
but <-ilso a large number of secondary effects which arise from
the effects of stress. The general method followed is that of
the magnetic circuit, as introduced by J. and E. Hopkinson,
a method which is analogous to the electric circuit method for
dealing with electric currents. By means of this method
great simphfication arises in the solution of problems in con-
nection with dynamos and transformers. The chapter which
will probably be found the most interesting to readers of this
journal is that on " .Molecular Theory," in which it is shown in
detail how all the properties of a piece of iron can be imitated
by a group of small pivoted magnets. When these are arranged
at random the assemblage behaves like non-magnetised iron.
When placed in a magnetic field a certain amount of alignment
takes place amongst the small magnets ; the assemblage has
then all the properties of a magnet, and this is the more so as
the alignment becomes more complete. The concluding
chapter on " Practical Magnetic Testing " is new to this
edition.

An Introduction to the Study of Colour Phenomena, by J. W.
Lo\ibond (E. and F. X. Spon, Limited, London). — The main
object of the work described in these pages was the construc-
tion of a series of glass standard colour scales, which are
correlated to some physical colour constants, and by means of
which a colour sensation can be measured, recorded, and
reproduced at svill. The author adopts coloured glasses for
this purpose, and has had constructed a series of grades of
glass of different tints, by comparison with which — taken
singly or in combination — any colour can be classified. To
physicists who are accustomed to refer all tints to a standard
spectrum, specifying each by the wave-length of the light re-
ferred to, such an elaborate system of coloured glasses seems
not only unnecessary, but somewhat arbitrary. The writer of
this notice has seen a box of these glasses, and the standard
yellow glass appeared to him to be a distinct citron-green.
This in itself is, of course, no serious objection, assuming that
the same standard tint can be reproducible at will. To ensure
this a comparison is made with a definite thickness of the
solution of some pure salt, such as copper sulphate. Although
the arbitrariness of the scale of tints makes them useless for
scientific purposes, it is possible that they may be of use in
the identification of certain manufacturing products. We do
not think, however, that their limited utility will repay the
enormous labour which has evidently been spent in producing
them. This small volume is beautifully illustrated by hand-
coloured diagrams.

Researches on the Affinities of the Elements, by Geoffrey
Martin, H.Sc. pp. xii. and 2.S7 (London; Churchill; price,
i6s. net.). — Since the days when Newl.inds pointed out that the
elements arranged in the order of their atomic weights exhi-
bited progressive relationships recurring at certain periods in
the series, this " periodic law," as it subsequently became in
the bands of Mcndeljeef, has formed the basis of much of the
speculation in chemical philosophy, and has borne fruit in the
di.scovery of new elements predicted theoretically as necessary
to fill gaps in the series. Mr. Martin's ,book also deals with
certain aspects of the periodic system, and is a valuable con-
tribution to the philosophy of chemistry. It is well known
that the various elements differ in their degree of attraction
for other elements, but hitherto no systematic attempt has
been made to discover whether these affinities varied in accord-
ance with any rule. Numerical dat.a are very scanty, and
consist of measurements of the heat of combination of the
different elements with one another, and hence the author's
conclusions have had to be based largely on qualitative differ-
ences in the readiness with which parallel conipoimds can be
decomposed into their constituents. Hut after making allow-
ances for the roughness of the method, it is shown that when
the elements arc arranged in their periodic order, their
" affinity surfaces," when compared, assume "the positions
of an advancing wave " repeating itself at the succes-
sive cycles in the system. Full directions for obtaining
these geometrical representations or " affinity surfaces " are

I given, together with a large folding plate showing those of 14
I of the more important elements. This " wave law " is illus-
trated by an immense amount of experimental results collected
from scientific publications and arranged in tabular form.
Several other conclusions are drawn from a consideration of
the facts, and all are supported by very able reasoning.
Unfortunately the style frequently leaves much to be desired,
and the book teems with irritating misprints, in addition to
the long list of errata given at the end.

Elementary Chemistry: Progressive Exercises in Experiment
and Theory, by F. R. L. Wilson, M.A., and G. W. Hedley,
.\I. .A., pp. \ii. and 167 (Oxford: Clarendon Press; price js.). —
The authors state in their preface that this book is intended
to train the thinking powers of the pupil rather than to fill
him with chemical facts, and the series of progressive exercises
and questions they have devised appears admirably adapted
to carry out this aim. They begin with simple measurements
involving the use of the metric system, and then deal with the
construction of simple apparatus, the thermometer, the chemi-
cal balance, solution and crystallisation, the properties of
liquids, and finally the identification of substances by their
physical properties. In short, it would be difticult to find a
more thorough or complete introduction to physical chemis-
try. The book is well printed on good paper, and gives clear
illustrations of the apparatus described in the text.

An Intermediate Course of Mechanics, by Alfred W. Porter,
B.Sc. (Murray ; price 5s.). As may be gathered from the title,
this book is intended for students at College Lectures, and
aims at giving them a clear idea of general principles rather
than fulness of details. The subjects of rectilinear translation,
momentum, vectors, Ike, are clearly explained, and the mathe-
matics introduced are not too deep, as is so often the case in
such text books. .\ chapter on the Mechanics of Fluids is
added, and appendices give many examples and specimen
examination papers.

The Origin and Influence of the Thoroughbred Horse (Cam-
bridge Biological Series, 1905 ; pp. x\ i. and 53S. illustrated ;
price, i2s. 6d. net). — Although an arch;i;ologist in place of a
naturalist by profession, the author of this well-illustrated
volume is to be congratulated on having brought together a
vast store of valuable information — nuich of which was diffi-
cult of access to the ordinary naturalist — with regard to the
vexed question of the origin and distribution of our domesti-
cated breeds of horses, and more especially the English
thoroughbred and its ancestral type — the Barbs, Turks, and
Arabs. It is true, indeed, that he is somewhat vague as to
what constitutes a species and a sub-species, or race, and that
there are ninnerous inconsistencies and errors in his summary
of the existing forms of the liiiiiidu- ; but, as a matter of
fact, this part of the subject has comparatively little bearing
on the main thesis of his work, and, in our opinion, it
would have been no loss had the greater part of this been
altogether omitted.

The author's main contentions appear to be as follows.
Adopting the views of previous works as to the distinctness
of the thoroughbred stock from that of the horses of
northern Europe and northern and central Asia, Professor
Ridgeway believes in the existence of three distinct types of
horse. Firstly, the Celtic type, from Iceland, the Hebrides,
and other parts of north-western Europe. Secondly, the tar-
pan, now represented by some forms of the so-called Eipius
przeuiilskii, of Mongolia. And, thirdly, the North African, or
Barbtype, inclusive of Arabs, Turks, and the modern thorough-
bred. The first two are represented by small breeds of large-
headed horses, showing a marked tendency to dun-colour, with
dark brown legs. From their small size, they were first
broken for driving instead of riding, and, owing to their in-
tractable disposition, were controlled by means of the bit. The
Barb typo, on the other hand, is represented by horses of
larger size, with relatively smaller heads, and of more sN-nder
build, whose typical colour appears to be Ijay, frequently
accompaniird by white " stockings " and a white star on the
forehead. Their more tractable disposition led to these horses
being controlled by a nose-band in place of a bit, while from
their superior size they were in the first instance broken for
riding. Northern Africa is held to have been the original
home of this stock, which was not introduced into Arabia
till a comparatively recent date. Barbs, Turks, and finally

December, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

307

Arabs formed the original basis of the thoroughbred strain ;
but Barb stock, in the author's opinion, is also to be detected
in the EngHsh Shire horse, as indeed in most of the dark-
coloured breeds. With the general scope of these conclu-
sions, most naturalists will, we think, be disposed to agree;
but in regard to the place of origin of the Barb-Arabian
stock, and the now extinct wild form from which it is
derived (on which latter point the author is in the main
discreetly silent), there may be two opinions, and the question
will have to be solved by paheontological evidence. As to
the value of Prof. Ridgeway's work — to those capable of read-
ing between the lines — there can be no question.

Religion for all Mankind, by the Rev. Charles Voysey (Long-
mans, Green, and Co. ; is. net). Religion, in its wide sense,
is a subject usually of the most polemical nature. The
belie\ers of one pursuasion are never in agreement with the
expositors of another system. Statements in the Bible and in
other code books are frequently called in question by those
not imbued with the sentiment that binds them to that par-
ticular creed. Vet here is propounded a religion '• based on
facts which are never in dispute." The tenets of the Theistic
Faith have long been known, but Mr. Voysey, wisely enough
from his point of view, desires to instil into the minds of his
fellow-men more evidence of the reasonableness of the
principles which he propounds. He keeps himself absolutely
clear of all so-called " Divine Revelation " as authority, and
by so doing can give offence to none. Many of the true and
beautiful words of the Bible are quoted, but only as illustra-
tions, not as a basis of belief. Compared with the dogmatic
assertions of some religious writers, who, in their narrow
minds, presuppose that their readers must believe every word
they are told, the simple statements here given are a pleasure
to read. " It is the right and duty of every man to think for
himself in matters of religion," is the first article of Theistic
Faith, and whatever form of religion we may happen to
adhere to, we must agree that such a sentiment is perfectly
correct, and this is typical of the book. We find throughout
but little that can be objected to. There may be many who
will not wax enthusiastic over these teachings ; but, we think,
all will agree that the author's words are fair and straight-
forward, and that to carefully peruse such a book tends to
make us better men.

How to Know the Starry Heavens, by Edward Irving (Fisher
Unwin; priceSs.6d.net). — This is decidedly a good book. Its
title and style are unassuming. One might have expected it
to be a mere guide to the constellations, and, being by an
American, one would not have been surprised had it referred
to other matters entirely, but it is very much more than that.
To call a small book of 300 pages a complete work on Astro-
nomy would of course be a little too much, but in these pages
there is very little of importance, to the man-in-the-street, that
is left out. The wording is simple and explanatory, and due ex-
pression is given to the wonders described. Some pages digress,
perhaps, too much into the fanciful. We are taken a trip into
space "in the chariot of imagination," and, when half-way to
the nearest star, we are told that " the scene is grand beyond
the power of language to describe." Why it should be any
grander than the view from our humble little earth on a
clear night we do not know. We are then taken to visit
" one of the stars." But a description follows which applies
right enough to our Sun, as far as we know it. But do we
know that any other star has " a glowing surface or photo-
sphere, which has the appearance of being dotted over with
still brighter specks like rice-grains " ? And so on. Even
the planets circling around it are in turn described. Why
not call the Sun the Sun ? Useful comparisons and similes
are given to impress upon our mind the relative dis-
tances of heavenly bodies. It is thoroughly characteristic
of the author's nationality not merely to point out that it
would take 5000 years to travel by express train to Neptune,
but also to add that "the railway fare, at one cent a mile, would
be nearly $28,000,000 — this makes a railroad impracticable ! "
The book is most admirably illustrated, not only by reproduc-
tions of some of the beautiful photographs now available, but
also by several coloured plates.

Results of Rain, River, and Evaporation Observations made in
New South Wales during 1901-2. — For many years past an
annual volume containing the results of the rain, river, and
evaporation observations made in New South Wales has been

published, but owing to the economies recently enforced by the
State Government, the volumes were suspended for some time.
The results for the two years icjoi and 1902 have now been
issued in one volume. Mr. H. C. Russell, F.R.S., the Govern-
ment Astronomer, has been successful in getting together an
army of over seventeen hundred voluntary rainfall observers.
The annual volumes have become extremely valuable as so
many interests are dependent upon the rainfall in the Colony.
The two years igoi and 1902 were marked by severe
drought. In the year 1902 the average rainfall for the whole
State was only i4"09 inches, which was the lowest average on
record, with the exception of 1888, when the rainfall was i3'40
inches. The year 1S88 was, however, followed by a series of
years having plentiful rainfall, while 1902 on the contrary
was the eighth consecutive year of drought. The drought was
most intense in the western country, where dust and sand
storms prevailed, caused by persistent dry winds. Sand
storms proved a most destructive agent in the back country;
drift sands and light dead weeds were carried over the plains
until stopped by fences, where the banked-up sand formed
dunes. The eftect of the drought was most severely felt in the
sheep-rearing industry. Mr. Russell says: " During the seven
years ending 1901 the number of sheep grazing in the Western
Division had dwindled from 16,000,000 to about 5,000,000.
Taking into consideration the value of the sheep as a wool-
producer, and the possible natural increase had there been
no drought, this represents a loss to the State of at least
/"30,ooo,ooo. In the case of Momba Station, which is one of
the largest in the State, the biggest shearing in one year was
420,000 sheep; in the year 1902 this number became reduced
to 70,000." The effect of the drought is shown in a peculiar
manner by the decrease in number of voluntary observers ;
in previous years these had shown a steady annual increase,
from 96 in the year 1878 to 1719 in the year 1901, but this
number fell to 1650 in the year 1902, which was brought
about in a large measure liy owners being compelled to
temporarily abandon their homesteads.

Results of Meteorological Observations in New South Wales
during 1900, 1901, and 1902.— This volume contains the daily
observations made at the Sydney Observatory, and the
monthly results from about fifty stations in various parts of
the Colony.

Successful Negative Making, by T. Thorne Baker, F.C.S.,
P'.K.P.S. (F(it((S office. Harp Alley; price 6d.), is a simple little
book of 40 pages, which puts clearly and concisely, yet quite
fully, all about dry plates, in theory and practice, exposures,
and developments. It is quite a good practical guide, but
would certainly have been the better for a list of contents and
an index.

Pattern Making, by Joseph E. Dangerfield (Dawbarn and
Ward ; 6d. net), is one of those useful and thoroughly prac-
tical little guides included in " The Home Worker's Series,"
which will be found of great assistance to those entering upon
such work.

Problems of the Future, by Samuel Laing, is now issued in a six-
penny reprint published by Messrs. Watts and Co. The book
is already very well known, and we can only advise those who
have not read it to make a point of acquiring it and spending
a few odd half-hours among the realms of the fascinating
mysteries of science. The book has been revised and brought
up to date by Joseph McCabe.

Thermometers and Pyrometers. — Messrs. John J. Griffin and
Sons have issued a catalogue of their instruments for measur-
ing temperatures from —200"^ C. to 4000'^ C, which include
almost every variety of mercury thermometer and electrical -
resistance pyrometers.

Science Data and Diary is an excellent little pocket-book,
issued by Messrs. Philip Harris and Co., of Birmingham, and
is replete with useful information on physical and chemical
matters, together with a diary, cash account, &c.

We have received from Messrs. Hirschfeld Bros, a set of their
Stay Cahndar for 1906, price is. net. This consists of 4 cards,
suitable for hanging up, on which a rough but clearly marked
map of the constellations "as seen in the northern hemisphere
in January, February, and March," (or other three months) is
given. There is also a calendar for each month, and a list of
planets with the constellations in which they are to be found
during the month.

3o8

KNOWLEDGE & SCIENTIFIC NEWS.

[December, 1905

Conducted by F. Shillington Scales, f.r.m.s.
Elementary Photo-micrography.

{Coutiiiucil from /rtg'<" 2S0.)
U.VDER any circumstances the lamp or other source of
illumination must be provided with some means of ad-
justing it both vertically and laterally. This is nearly
always provided with the oxy-hydrogen jet, and the
ordinary microscope lamps are generally supplied with
an upright rod upon which they move vertically. The
horizontal adjustments are easily obtained by arranging
a wooden stand to run lengthwise in the parallel guides
of the baseboard, and another stand above this running
in parallel guides, who.se motion is across and at right
angles to the lower stand. The two can be clamped
together with a thumb-screw. Such an arrangement
could easily be made at home.

It will be found a great convenience if a similar stand
be made for the microscope, but the more general
method is to arrange a clamp of some sort and shoulders
against which the foot may come so that once the
microscope has been definitely adjusted in its proper
position and the shoulders fitted accordingly it may be
an easy matter to replace the microscope at any time
and to clamp it securely, with the certaintv that it is
correctly placed. The Continental stand with its horse-
shoe base is so unsteady when in the horizontal position
that it absolutely needs some such clamping arrange-
ment, but the English tripod is nearly as steady in this
position as when upright, and in the case of one of my
own microscopes I have merely to drop the three feet
of the stand into three little metal rings screwed on to
the baseboard and which were carefully placed correctly
once for all.

The loss of light in photo-micrography is so consider-
able that some means of strengthening the illumination
is necessary, and this is done by means of an auxiliary
condenser placed between the light and the sub-stage
condenser of the micro.scope. A further necessity for
such an auxiliary condenser is due to the importance in
photo-micrography of equally illuminating the whole
field of view. With ordinary visual microscopic work
this is not necessary, and the advanced microscopist
rigidly focu.ses his lamp flame with a view to getting
the lx;st image in the particular portion of the field
under examination, and cheerfully neglects the com-
paratively ill-illuminated portions of the field on each
side. But this is manifestly not admissible in a photo-
micrograph, and any alteration in the focus of the sub-
stage condenser to do away with this light streak would
not only depreciate the image, but cause a considerable
loss of light. So the auxiliary condenser is intcrpo.sed.
There are three ways in which this condenser can be
adjusted, and this is a point that is generally in-
sufficiently dealt with in books on the subject of photo-
micrography. To begin with, the auxiliary condenser
can be adjusted to give parallel light or converged light.
Of these, the second is the one usually u.sed, the bull's-
eye being so adjusted as to bring the light to a focus 10
inches or so away from the sub-stage condenser, which

is then focussed on this point. A little experimenting
with the bull's-eiie in various positions will be found
very instructive and helpful. The plane side of the
bull's-eye should be turned towards the light and
brought comparatively close to it, as in this position
the aberrations of the ordinary uncorrected nearly hemi-
spherical bull's-eye are least in evidence.
(7\> he contiiincd. )

Royal Microscopical Society.

.\t a meeting licld on October iS at 20, Hano\er
Square, Dr. Dukiiilield H. Scott, F.R.S., President,
in the chair, an old Wilson screw-barrel simple micro-
scope, date about 1750, presented by Major Meade J. C.
Dennis, was described by the Secretary, who traced
the history of microscopes, focussing by means of a
screw cut on the body-tulae, from Campani in 1686,
Grindl in 1697, Bonnani in 1691, Hartsocker in 1694,
to Wilson in 1702, who was followed bv Culpepper
some time prior to 1738, and Adams in 1746. Mr. V..
.Moffat exhibited and described a simple portable
camera for use with the microscope. It consisted of a
vertical telescopic standard drawing out to 28 inches,
with .1 clamp at its lower end to secure it to the edge
of the table. At the upper end of the standard was
fixed a mahogany board, J inch thick x 4 ins. x 5 ins.,
hinged at the pillar so as to close up, and having a
hole in the centre about 3 ins. in diameter. There were
two spring clips for .securing the dry-plate while
making the exposure, and guides for keeping it in
position horizontally. The back of the dry-plate was
covered by a piece of cardboard painted dead black,
the spring clip referred to pressing upon this card.
Depending from the board was a tapered bag of black
Italian cloth about 17 ins. long with a rubber ring at
the lower end to secure the covering to the eyc-picce of
the microscope. The apparatus can be closed up into
a space 5 ins. X 9 ins. x li ins., and will thus go into
a large pcx:ket or a knapsack. If made of aluminium
the weight should not exceed ij lbs. The designer
stated that this camera would work well up to 700
diameters, and could be made in brass for 21s., though
aluminium would cost more. The Secretary cxhil)ite{l
and described a hand microtome designed and used by
Mr. Flatters. It was made of brass .-md had .1 tube
3 ins. long and i in. inside diameter. The spindle had
a screw of 28 threads to the inch, and was actuated at
the lower end by three interchangeable notched discs,
engaging with a spring stop, the tension of which
could be adjusted. .Si'ctions could thus be cut varving
from TjTs'jyn to 1255 inch in thickness for each notch that
the disc was turned. The knife-plate was made of
hardened brass. The aperture on the upper side was
of somewhat smaller diameter than the rest of the
tube to prevent the specimen turning. Messrs. R. and
J. Beck exhibited the Aske Finlayson "Comparascopc"
(described in " Knowledge " for November last, page
281). A paper was read by Prof. Henry (J. Hanks, a
corresponding Fellow of the .Society, entitled " Notes
on .'\ragotilc, a Rare Californian Mineral," first d -
scribed by Mr. F. V.. Durand in a paper read before the
Californian Academy of .Sciences on April i, 1872.
The President called attention to an exhibition of a
number of slides froin the collection recently pr«'sented
to the .Society by Mr. W. M. Bale, of .Melbourne, in-
cluding some exrellcntiv moimterl orchid seeds.

Quekett Microscopical Club.

At the 424th ordinary meeting of the Quekett Micro-
scopical Club, which was held at 20, Hanover Square,

December, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

309

W., on October 20, the President, Dr. E. J. Spitta,
F.R.A.S., in the chair, Mr. James Burton read a paper,
" On an Easy Method of Staining and Mounting
Micro-AlgEe and Fungi." The method described may
be briefly summarised as follows : — Fix the fungus by
one or more drops of 90 per cent, alcohol; follow with
25 per cent, alcohol; wash out with distilled water; add
a drop of glycerine stained with Hoffman's blue, and
cover. The fungus absorbs the stain from the
glycerine, which acts also as a preservative medium.

Mr. F. P. Smith continued his revision of the classi-
fication of the spiders of the sub-family Erigoninae,
dealing with those species which he included in the
Walckenaeria group. A complete bibliography of the
group will appear in due course in the Club's journal.

Mr. .Smith also described a new British spider from
Great Yarmouth, under the name Anglia hancockii. It
is one of the largest known forms of its sub-family, the
Erigoninae, and appears to be of a very early type.

There was a crowded meeting of members, who
listened with regret to the announcement of the death
of their veteran Vice-President, Mr. J. G. Waller, who
had died on the previous day at the great age of 92.
Mr. Waller, who was also well known as an artist and
archaologist, joined the Quekett Club in 1868, and had
served for a great number of yeais on the Committee.
He was elected President of the Club in 1896 and again
in 1897, ^nd served as a Vice-President from 189S until
his death.

Notes and Queries.

Capt. H. D. Foulkes, Fort Purhrooh. — Your question raise.s
an interesting and practical point. The resolving power, that
is, the ability to separate a maximum number of lines to the
inch, is directly dependent upon the numerical aperture of the
objective. Therefore a ,1 inch of N.A. 1-5 will tlieoretically
have the same powers of resolution as a ,\, inch of the same
aperture. But to resolve a number of lines and to make them
evident to the eye are two different things. The average
normal eye is generally stated to be able to distinguish 200
lines to the inch at the normal visual distance of 10 inches.
Therefore the image given by either ol:>jective must be magni-
fied sufficiently by the eye-piece to make such lines distin-
guishable by the eye. Now, in theory apochromatic objectives
will bear any amount of eye-piecing, but this is not so in prac-
tice, even apart from the loss of light, and the higher powers
bear high eye-piecing less satisfactorily than the low powers.
These limitations are still more evident with achromatic objec-
tives. So that if the maximum resolution be imperatively re-
quired a ,'. inch of N.A. 1-5 would in practice be less satisfactory
than a higher power of the same aperture because of the high
eye-piecing required to make the lines visible. But if such
maximum resolution be not requisite, in other words if the
object does not need such extreme resolution, then there are
several advantages attendant upon the use of the lower-powered
objective of the same aperture, t^irstly, the working distance
is greater; secondly, the field of view is larger; thirdly, the
loss of light of the two objectives is proportional to the square
of the magnification ; and fourthly, though the amount of light
dependent on the aperture varies as the square of the N.A.
(which of course in any pair of objectives increases in a much
smaller ratio than the magnification) in the two objectives
under discussion the N.A. is identical. Tlierefore. if the work
is of such a nature that moderate magnification only is re-
quired the lower-powered objective is preferable. With a pair
of still higher powers of equal aperture the lower power would
be preferable under almost all circumstances. Let us take for
instance a jij inch achromatic of N.A. vz^ and a y", inch of
the same aperture, or an apochromatic 5 inch of N.A. i'4 and
a ^, incli of the same aperture. In the first case a quite
moderate eyepiece, which the objective can well stand, will
show all that a ^. of N.A. 1-25 can resolve and the drawbacks
incidental to using a ^^ inch of higher magnification, but of

the same aperture will bring with them no compensating
advantage. With the pair of apochromatics of N.A. 1-4 the
I inch will require rather higher eye-piecing to make the
maximum amount of structure evident, but still it will not be
more than an apochromatic can well stand, and so it again is
preferable to the ji.lh.

./. T.Orme, Kor/c— For the chemical tests for mechanical
wood pulp and esparto grass (as aids to microscopic exami-
nation only) I must refer you to my series of articles in
" Knowledge " on the "Fibrous Constituents of Paper " in
the issues of February, March, April, and May of this year,
pages 42, 68, 92, and 114. There are no chemical tests in
bulk, unless the somewhat untrustworthy use of aniline sul-
phate as a test for mechanical wood pulp may be looked upon
as such. Cross and Bevan's book is the best text-book on
papermaking, and deals with such chemical analyses as are
practicable for paper. Griihn and Little's book is more a
manual of chemistry specially written for papermakers. A
very good little book in certain respects is Hertzberg's
" Paper Testing," tianslated by Dr. Norman Evans, and pub-
lished in 1S92 by W. J. Stonhill, at the offices of the Paper
Trade Revic-cV. This is the nearest of the German books to
what you require. I am afraid I cannot give you any infor-
mation on the subject of "smalt," other than you appear to
have already, and I am sorry that the many claims upon my
time will not permit of my making an analysis for you of the
sample you send.

Major E. F. BccJur, Chi-ltc]iha>ii. — You do not give me the
focal length of your bullseye, so it is not quite easy to answer
your question definitely. The most obvious suggestion is that
the 2 inch objective takes in a larger field than the sub-stage
condenser could illuminate, until in altering both condensers
you adjusted the latter so that the rays crossed and thus
illuminated the wliole field. If you were using one of the
ordinary Abbe sub-stage condensers and not one of the new
macro-illuminators, this is probably the correct explanation.
Of course, if your Ught were correctly focussed upon the object
you would get a disc of light smaller than the objective with
the I inch also, but the spherical aberrations of the bullseye
you had interposed between the light and the sub-stage con-
denser would prevent such accurate focussing, and you would
thus get a disc of light large enough to illuminate the whole
field taken in by the latter objective. With regard to investi-
gations into the nervous system of insects, a certain amount can
be done by careful dissecting, especially in gaining a true im-
pression as to the relations of various parts. This will, of
course, need to be done under a dissecting microscope and
probably under water, the insect being pinned down to wax
run into the bottom of the dissecting dish or to a piece of cork
weighted with lead and placed in the dish. I do not think it will
be practicable to attempt to stain the nerves and their ganglia
in situ by any differential stain which will stain the nerves only,
whilst the other parts and the chitinous exo-skeleton are left
transparent. Your method will therefore be to proceed by
means of serial sections, both transverse and longitudinal, and
this will need careful preparation of the object beforehand, and
a certain amount of experiment before you decide on the best
fixing and other reagents and stains. For fairly thick sections
the celloidin method will do, and the sections can then be cut
with any good microtome. But for really first-rate sections
the object must be prepared for infiltration with paraffin (not
embedding merely), and be cut on a good rocking microtome
such as the well-known instrument made by the Cambridge
Scientific Instrument Company. Have you had any experi-
ence of infiltration methods ? If so, your task will be greatly
lightened. You will probably have to stain the sections upon
the slide by some differential nerve stain. Eau de Javelle
would probably be a good method of making the chitin trans-
parent, as it is stated to have no effect upon such delicate
structures as nerve endings and to render the chitin permeable
to staining Huids, but my experience has betn that it requires
to be used with great care. The sohition should be diluted to
4 or 6 times its volume of water, and the object left in this for
24 hours, or much moie, accordirg to size. You might use
this reagent before dissecting. If you then wish to go on to
make serial sections, I will try to explain how to set about it.

[Communieiitions tiini Eiicjiiiries on Microscopical maltirs should he
iiddrcsscd to F. i:hiiiington Scales, ^'Jersey," St. Barnabas Hoad,
Cambridge.']

3IO

KNOWLEDGE & SCIENTIFIC NEWS.

[Deckmber, 1905.

The Face of the Sky for December.

By W. Shackleton, F.R.A.S.

The Sun. — On the ist the Sun rises at 7.46 and sets at
3.52 ; on the 31st he rises at 8.S and sets at 3.5S.

The equation of time is negligible on the 25th.

Winter commences on the 22nd, when the Sun enters
the sign of Capricorn at noon. Solar activity is well
marked, many spots of late being visible to the naked
eye, whilst prominences have been particularly brilliant.

The following table gives the position, angle of the
Sun's axis, and the heliographic latitude and longitude
of the centre of the Sun's disc : —

Date.

Axis inclined
from N. point.

Centre of disc

N. or S. of Sun.-

Equator.

Heliographic
Longitude of
Centre of Disc.

Dec. 2 ..

,, 12..

.. 22 . .
Jan. I ..

11° 35' E

6^ 5S' E
2° 8' E

0" 33' N.
0° 44' S.
2° 0' S.
3° II' S.

310° 44'

178° 58'
47° 14'
275° 30'

The Moon

: —

Date.

Phases.

Dec. 3 ..
„ 11 ..
.. 19 --i

.. 26 ..

3) First Quarter
0 Full Moon
d Last Quarter
• New Moon

6
II
0

38 p.m.
26 p.m.

9 p.m.

4 a.m.

.. 7. -I
.. 23 -I

Apogee 252,100 miles
Perigee 225,800 ,,

10
10

6 p.m.
12 p.m.

OCCULTATIONS ;

Disappearance. Reappearance.

8 M Ceti 4-4

9 / Tauri 4'3

10 y Tauri 3*9

10 75 Tauri 5-3

10 B.A.C. 1391.. .. 4'9

1 1 Aldebaran . . i ' i

pm.
5-35
4-49
4-58
10.3

11.37
a.m.
2.52

Angle

froiiiN.

Mean

point.

Time.

p.m.

52°

6.43

lOl'

5-43

84°

5.56

60°

11.22

137°

12.18

a.m.

109°

3-53

Moon's
Angle Age.
fromN
point. .

263°
220°
244°
269°
'97°

238°

The Planets. — Mercury (Dec. i, K.A. 17'' 58"*;
Dec. S. 25° 26'. Dec. 31, R.A. 17'' 4"" ; Dec. S. 20° 23').
Throughout the month the planet is not suitably placed
for observation, being in inferior conjunction with the Sun
on the 15th.

Venus (Dec. i, K.A. 15'' 14"'; Dec. S. 16^ 48'.
Dec. 31, R.A. 17'' 53ni; Dec. S. 23'^ 23') is a morning star
in Scorpio, rising only a short time before the Sun, hence
the planet is not well placed for observation.

Mars (Dec. i, K..\. 20'' 52"" ; Dec. S. 19 6'. Dec. 31,
R.A. 22'' 21"'; Dec. S. iT" 20') is a feeble object in the
evening sky situated in Capricorn and Aquarius, setting
about three hours after the Sun.

Jupiter (Dec. r, R..\. 3I' 54m ; Dec. N. u/17'; Dec. 31,
R.A. 3'' 41"' ; Dec. N. i8- 41') is a brilliant object in the
evening sky and is describing a retrograde path in
Taurus. Towards the end of the month the planet will
be situatedahout fi vedegreesdirectly south of the I'leiades.

The planet is very favourably situated for observation
before midnight, and forms with his belt-like markings
and bright moons a most interesting object even in very
small telescopes.

The equatorial diameter of the planet on the 15111 is
4b"-5, whilst the polar diameter is 3"i smaller. The

following table gives the satellite phenomena visible in
this country, before midnight : —

I. Oc. D.

III. Sh. E.

n. Oc. D.

L Tr. L

I. Sh. 1.

U. Ec. R.

I. Tr. E.

I I. Sh. E.

1. Oc. D.

1. Ec. R.

! I. Tr. E.

I. Sh. E.

nil. Tr. I.

III. Sh. I.

III. Tr. E.

II. Oc. D.

III. Sh. E.

I. Tr. I.

I. Sh. I.

II. Ec. R.

II I

5 7

6 6
8 16

8 29

9 3
10 27
10 42

5 27

7 52

4 53

5 'O
5 48
7 15
7 21
S 19
9 8
9 59

10 23

11 39

I. Oc. D.

I. Ec. R.

L Sh. I.
II. Tr. E.
II. Sh. E.

1. Tr. E.

I. Sh. E.
III. Tr. I.
II. Oc. D.
III. Tr. E.
III. Sh. I.

I. Tr. 1.

I. Oc. D.

1. Ec. R.
II. Tr. I.

I. Tr. I.
II. Sh. I

I. Sh. I.
II. Tr. E.

7 "
9 47

4 52

5 20

6 17

6 37

7 5
9 5

10 34

10 41

11 16
II 44

857
II 43

5 5

6 ID

6 19

6 47

7 38

Tr. E.
Sh. E.
Sh. E.
Ec. R.
Oc. D.
Tr. I.
Tr. I.
Sh. I.
Sh. I.
Tr. E.
Tr. E.
Sh. E.
Sh. E.
Oc. D.
Ec. R.
Ec. D.
Sh. E.
Ec. R.
Ec. R.

8 22
855

9 o

6 12
10 43

7 24

7 56

8 42
857

9 58
10 8

10 55

11 34

6 7
C 57

"Oc. D." denotes the disappearance of the Satellite behind the disc, and
"Oc. R." its re-appearance ; 'Tr. I." the ingress of a transit across the disc,
and " Tr. E." its egress ; " Sh. I." the ingress of a transit of the shadow across
the disc, and " Sh. E." its egress.

Saturn (Dec. i, R. A. 2ii> 59m; Dec. S. 13° 59'.
Dec. 31, R. .\. 22'' Sm; Dec. S. 13" 11') is due south
about sunset and well placed for observation during the
early part of the evening ; near the middle of the month
he sets about 9.20 p.m. The ring, which can be seen in
small telescopes with moderate powers, appears well open
aswearelookingat anangleof lo'^jOnthe northern surface.

Uranus is in conjunction with the Sun on the 25lh,
and hence is unobservable.

Neptune (Dec. 16, R. .\. 6'' 41-"; Dec. N. 22 g') rises
about 5 p.m. near the middle of the month, and is due
south about i a.m. The planet is situated in Gemini,
some 6^ east of the star m Geminoruni, but in small tele-
scopes without setting circles, it is difficult to identify
from the numerous small stars in the same lield of view,
but he can be detected by his motion if observations are
made on several successive nights. The planet is in
opposition to the Sun on the 31st.

Meteors : —

The principal shower of meteors during the month
is the Geininids, Dec. 10 to 12; the radiant is in
R. A. VII'' 12'", Dec. + 33°. The mcteois are short
and quick, and difficult to record accurately.

Minima of -Mgol may be observed on the 3rd at
10.49 p.m., the 6th at 7.38 p.m., 26th at 9.21 p.m., and
29th at 6.10 p.m.

Telescopic Objects : —

Double Stars :— 1 Pegasi XXI*" 17.5'", N. 19" 20',
mags. 4'5, 8-6 ; separation 36"-2.

TT Andromeda; o*" 31. 5", N. 33' 'n', mags. 4-0, 8'o ;
separation 36"*3.

a Piscium I*" 56.9"', N. 2 •17', mags. 3-7, 4-7 ; separa-
tion, 3"'6.

I Trianguli 11"6.G"', N.29"'5o'; mags. 5, 6-4 ; separa-
tion, 3"'5.

Clusters:- (IJI vi.33,34). The Perseus clusters visible
to naked eye and situated about midway between y Persei
and 0 Cassiopeia . These magnificent clusters are de-
scribed by Smyth as "affording together one of the most
brilliant telescopic objects in the heaxens."

(M. 34.) A mass of small stars about the 8th magni-
tude; not very compact. The cluster is just perceptible
to the naked eye about 5' N.W. of Algol.

December, 1905. J

KNOWLEDGE & SCIENTIFIC NEWS.

311

SUPPLEMENT.

[Although it has not been usual to include fiction within the pages of " Knowledge," the followirg
discourse, ic'hich is hut a tale built around a new and possibly important scientific proposition, seems
to be one not inahpvopriate to the contents of a scientific journal. — En.]

London's
TroLnsformatiorv.

A Suggestive Sketch of Da-ys to Come.

{Coniiniud from page 28(1.)
By Tems Dvvirta.

[Cornelius Tush was agreat .\meri-an financier, whose modes of
business were perhaps not always quite above suspicion. He had hit
upon the great idea of diverting the course of the Thames so as to
cause the river to flow away to the country, and leave its dry bed
in Londoa available for building sites ]

CH.XPTER \'.

Finesse.

For some days afterwards Mr. Tush was very busy
interviewing many of the leading engineers, contrac-
tors, and hand agents. To none did he reveal his great
ide:i. He consulted this one about the cost of a big
canal, laying down the conditions and circumstances,
and leading his adviser to the belief that he was re-
ferring to some new' Central American w'aterway. He
talked to that one about the price of land in Kent and
.Surrey, as though about to buv a large estate. With
others the expenses of bridges, of dams, of laving roads
and other items were discussed. So, bit by bit, he
compiled a full and complete estimate of his scheme.

The question was, would it pay? The new- river
should only occupy approximately the same area as the
reclaimed ground, so that as regards the cost of pur-
chasing land, it would onl}- amount to an exchange of
country for city property. Then again, much super-
fluous land would of necessity have to be bought border-
ing the deviation, but this would in all probability be
greatly enhanced in value for building purposes, and
might thus pay for the whole. There would then re-
main the value of, perhaps, 1,000 acres of reclaimed
land as an asset; some of this might actually be sold
before the water was removed from its surface; the
hind was there right enough. Xo one could deny
that !

Tush decided to play the bear. In compliance with
his invitation, numbers of influential men were calling
to seek an interview- with the great financier. Mr.
.Singman was one of the first to be ushered into his
sanctum. " You require a large building plot
centrally situated? "' said Cornelius. " Well, I'm not
a land agent, but I happen to know of the very article
you require, but, can you pay the price? " .Singman
quoted some figures as to his requirements, and as to
the capital he had at disposal to obtain the land. Tush

regretted that the plot he knew of would cost consider-
ably more, but then, he urged, it possessed such very
suitable characteristics as to make it well worth the
extra outlay. It had a large frontage on one of the
principal streets of the city, was so situated as to be
most easy of access by rail or 'bus, it had a wide pave-
ment in front, and was surrounded by fine buildings.
Singman, trying to picture the spot to himself, was
somewhat puzzled, and finally broke in by requesting
to be informed of the exact locality. "As I have
said," retorted Tush, " I am no common land agent;
this is an affair of some moment w hich requires secrecy.
I am not at liberty to impart to anyone exactly what
property this is, but you can take my word for it, it is
all that I describe. It is a great chance for you, and I
will give you the opportunity of thinking it over for one
day. I will then require a decided answer as to
whether you will take it or leave it." Singman
thought it over, and, as he had also " kept a bit up his
sleeve " by not naming so great a sum as could really
be devoted to the object, he eventually decided to scrape
together the required amount to purchase the unrivalled
site. \'ery similar dealings were negotiated with other
callers, till Tush felt that he had a very respectable
sum practically in his hands.

Yet, as he considered carefully over the question,
the vastness of the project and the many dilliciilt
problems involved filled his mind with doubts as to the
feasibility of the scheme. The few sales of land which
he had so far actually contracted for would, after all,
bring in but a small fraction of the enormous capital
necessary to complete the work. If but one of the land
owners on the site of the deviation refused to sell, the
whole plan might need alteration. The Bill which it
would be necessary to bring before Parliament would
certainly receive much opposition. The railway com-
panies might object, as might the steamboat owners,
and too large a compensation claimed.

On the other hand the whole matter had been very
carefully gone into and it ought to pay handsomely. It
was not likely to fail like the Panama Canal Companv
had done after spending sixty million pounds.

Could the Government do anything? Tush decided
to lay the project before them; leave them to disentangle
the multitudinous obstacle while he could make such
stipulations as to guarantee for himself a goodly p<'r-
quisite.

A few days later Tush was closeted with one of the
principal heads of the department concerned. Argu-
ments were adduced, such as a possible substantial
addition to the revenue, an investment as good as the
purchase of the Suez Canal shares, which increased six
times their value in twenty years, and many other nice
plums, calculated to attract a tottering ministry; but
the Right Honourable Gentleman addressed could only

312

KNOWLEDGE & SCIENTIFIC NEWS

[December, 1905.

reply that the matter was hardly one which tlie Govern-
ment could undertake, and that the public body most
concerned, and, therefore, the proper quarter to appeal
to, was the London County Council.

Interviewing the officials of the latter, and impress-
ing' upon them the great benefits to lx> derived from the
scheme, the lowering of rates by the huge income from
rents, and the great improvements to be introduced to
the city. Tush was again doomed to disappointment by
being informed that, on the whole, the scheme was con-
sidered to be of tof) speculative a nature for this body
to undertake.

Nothing remained, therefore, except to endeavour to
further the original idea of the formation of a huge
companv. -An attractive prospectus would have to be
concocted and issued I)roadcast, then, if the capital was
forthcoming 't would Ik" necessary to get a Rill passed
through Parliament to obtain rights for the compulsory
sale of land to the company and the abolition of various
vested rights.

A day or two afterwards Mr. .Singman was again at
the office craving an interview with the universal pro-
vider of moneys and lands. " I am getting a little
unea.sy," he confessed, "about our arrangements.
You have pictured to me an ideal site for my establish-
ment, yet though I have hunted London high and low 1
can find no such perfect place. Where does it exist ?
You might, at all events, name the district, if not the
street, in which it is." The wily Tush was a little
puzzled as to how to appease the curiosity of his client,
not wishing to ha\e to allow that the transaction was
certainly problematical and uncertain, and not likely in
any circumstances to be completed for some years to
come. However, by stating that it was not far from
the Houses of Parliament, that it was not south of the
Thames, and that it faced one of the main thorough-
fares, he succeeded in satisfying his over-inquisitive
friend for a bit. Just as Singman was leaving the
room, however, a thought struck him. " I thought
you said it was in the cify? " he suddenly interrogated.
" No," replied Tush with the greatest calmness,
" Westminster."

The next caller was FitzEdmund. " With respect
to this plot of land, Mr. Tush, about which we have
been negotiating, I happened to meet a day or two ago
a gentleman who was dining with you that day, if you
remember. Well, he mentioned that you were
arranging to sell him a great plot of land, too. It
isn't the same by any chance, is it? "

" Oh dear no; your theatre is to be in the vicinity of
the .Strand."

Having thus dispo.scd of another awkward customer,
Tush was feeling a little more relieved, when Lord
Whittingbournc was announced. " My dear Mr.
Tush, I don't at all understand what is going on.
While sitting in your waiting-room just now, a gentle-
man came in, having just left you, and staring at me
said, ' Oh, so I s'pose he's going to sell yon a bit of
City property, /nn, eh?' 'That is so, sir,' I replied,
' but I do not understand it all.' "

" Oh, there's nothing in that," said Tush, " that
man cf)uldn't scrape out the dollars to outbid you."

Then rumours spreafl around and were whispered
here and there in the highways and by-ways. The
great .American financier had gone off his head ! He
had been .selling plots f)f building land in the City freely
to all who applied to him, and had already negotiated
for the sale of such an amount as could not possibly
be disposable in all the City of I^ondon !

Tush at last got to hear of those rumf)urs. It wr)uld

be absolutely necessary to make some explanation to
appease the anxiety of those concerned, but how could
it Ije done?

.After long and careful consideration Tush came to
the conclusion that there was but one solution to the
difliculty. " Trust to truth." .Accordingly each of the
would-be purch.'isors h:id to be sent for o\er again, and
each had to 1m? carefully mollified and soothed, and to
be persuaded that immediate possession was of no im-
portance; and then the great scheme was gradually laid
before them, and the certainty of its success impressed
upon these " co-originators of the scheme, whose names
would be indeliblv connected whh this grand and bene-
ficial concern."

.\nd soon the world at large were also t.iken into
confi<lence. The glowing and persuasive prospectus
convinced all men of the soimdness and fcisihilitv of
the scheme, so that before many weeks had passed, a
new and cokissal company had sprung into existence,
b.'ickod hv the wealth of the nation.

CH.APTKR VL

Progress.

Three solid years had slipped by since the banquet at
the Savilc; and what a change was manifest !

Cornelius Tush who, one way and another had by
now recouped most of his lost fortune, stood once again
on W'cstminster Bridge surveving the river and its sur-
roundings. How different now the aspect to that
which had met his eye three years before ! That vast
expanse of water had now dwindled considerably.
C'ireat wooden structures rose from the water. Caissons
and hoardings hemmed in the rixer and limited its flow.
Beyond, extensive banks of brown earth supported
temporary lines of railway, along which crawled long
trains full of earth dug from .Surrey fields to fill in the
bed of the river. .\ narrow strip of water was left
along the southern hank forming a canal, crowded with
barges.

Moving down from off the bridge, Cornelius ap-
proached a w(mkI<mi shed among the lines bearing the
sign " Temporary Olfices," and soon after enierged
with engineers, and foremen, and others, and was
ensconced in an inspection car to go a trip round the
w-orks. The engine whistled and the little train rattled
off along the shaky, roughly-laid line, passed .St.
Thomas' Hospital rwid the great Houses of I'arli.ament
opposite, and on it jogged towards Wandsworth. Vast
were the works in progress. On all sides gangs of
men at work digging, picking, shovelling, laying new
lines, tearing up old ones, fixing up great cranes,
making bridges and dams, demolishing old houses,
erecting new sheds.

At Wandsworth was the junction where tlie devia-
tion began. And here were in course of erection some
large under-waler turbines, which, by the flow of the
river, were to convert its latent power into electrical
energy, and to supply London with that most valuable
commodity. Up the bed of the Wandli', that little
stream which but a few years before had run so placidly
and unostentatiously among the green meadows ;md
pollard willows, was now a vast v;illey of excavations.
Numerous steam diggers were puffing away ;it their
gigantic tasks. Temporary bridges were being con-
structed for the railway lines and various ro;ids passing
over it. On went the inspection train tf)wards Croy-
don. Here the work was stupendous. .An enormoiis
cutting, over 100 feet deep and of great width, was
being excavated. Hundreds of acres of siihinban land

December, 1905.]

KNOWLEDGE & SCIENTIFIC NEWS.

313

were covered with this turmoil. Houses of all sorts,
from the humblest cottages to the most magnificent
villas, had fallen a prey to the Act of Parliament sanc-
tioning the great work. Even whole villages had been
swept away by the remorseless hand of the now cele-
brated Tush.

At various points the train stopped, while Tush got
out to interview the officials or inspect some new piece
of work, and then on he would go again. Now the
distant form of the Crystal Palace, with Its two towers
so familiar to suburban /labi/nes, came In view as the
little train rattled along near the south end of its
grounds. Even further was the great ditch continued
through Beckenham and right on towards Greenwich,
where new docks were to be constructed, with great
locks to cut off the tide.

In some places, where land was not so precious, the
spare earth was piled up Into small mountains, instead
of being carried all the way round to the City, and these
would, in the future, form picturesque little hills over-
looking the river.

One of the greatest difficulties proved to be the many
railroads connecting the Metropolis with the south.
Either there would be required a large number of long
bridges, or they would need to be so altered and
arranged that a number of them could utilise the same
bridge, which was more economical In many ways.
Some, on a low level, could tunnel beneath the New
River.

Tush, satisfied with his tour of Inspection, now took
the ordinary train to convey him to the City, where he
was to attend a meeting of the company, and troublous
times were beginning to overshadow its peace and
prosperity.

The " Thames Deviation Construction Company,"
with its capital of _;^'5o,ooo,ooo, was one of the biggest
commercial concerns ever undertaken, and was not the
chairman also one of the biggest financiers the world
had seen ? Yet discontent was rife among the share-
holders. They wanted to know more. They asked
this and they asked that, but they were always put off
with vague replies. " Mr. Tush has arranged that,"
was considered a sufficient answer to allay all despond-
ency and doubt as to certain possible difficulties. Then
more sinister rumours began to get about; one of them,
for Instance, was to this effect : — •

A certain gentleman in business in the City owned a
small villa and a few acres of land near Carshalton.
About three years ago^ a stranger, giving the name of
Jones, called to see him and asked whether he was
willing to sell the freehold of his little property. In
due course the transaction was completed, and Mr.
Jones became owner of the land on very favourable
terms. .Since then the land had Ijeen purchased by the
Deviation Company for a very handsome sum; those
knowing its true value being much surprised at the
magnanimity of the great company. Well, all this
might not have seemed a matter of any Importance had
not the worthy City merchant one day chanced to have
pointed out to him the great Tush. "That Tush! "
he said, " why I could swear that that is the man
Jones, who bought my house at Carshalton." And
then other stories of a very similar nature got about.
It transpired that about the time the company was
first formed. Tush had become a very large shareholder
In the " Conrad R. Pickle Steam Digger and Excava-
tor Company," of Pittsburg, U.S.A., and that this
firm, though not the lowest contractors, had supplied
nearly all the machines used by the company for
excavating. So, too, a certain architect, to whom

much work had been entrusted, was found to be " sub-
sidised " by Tush. Either under his own name, or
that of his agent Bateson, he seemed to be interested
In many different concerns connected with the great
undertaking.

Thus it gradually began to leak out that the great
capitalist was making money " hand over fist " in a
number of different lines, quite apart from the main
company. Indeed, It was suggested by some of the
more pessimistic that he had already got rid of the
greater part of his " Deviation " shares during the
great boom of a year ago, and that he was now running
the thing so as to suit his own interests rather than
those of the shareholders.

Still all these awkward rumours were explained away
by the co-directors and officials of the company, and
things went on smoothly enough for some years. As
the completion of the works began to become manifest,
hopes rose in people's minds, and the shareholders
cared not what Tush did, only so long as the great work
should be satisfactorily completed.

CHAPTER VH.

The Opening.

At last all was ready. The huge cutting of the
" New Thames " was complete; all except the dam
which still held the waters, and bade them flow on In
the path they had pursued for centuries. Once the
dam was cut all would be changed, and the waters,
rushing wildly over fields and pastures new, would dash
onward to find their new course to the sea.

This, then, should be a most eventful occasion, and a
fitting ceremony was arranged to take place. Large
wooden stands were erected for the accommodation of
the thousands of spectators. Royalty itself was to
honour the proceedings with its august presence and
support. All the big wigs in England had expressed
their Intention of attending. Cornelius had decided,
in his usual personally ambitious manner, that this great
occasion was not only to be the opening up of the new
river, but that It would Incidentally form the ceremony
of exonerating him personally from all the wicked
slanders that had been circulating more and more
freely. He had made numerous plausible stories which
ought, he thought, to explain away any harmful inten-
tions on his part. But, unfortunately, as soon as one
was disposed of, dark tales sprung into life about some
other enormity that he was supposed to have com-
mitted. Now at last he hoped they were all satisfac-
torily explained, and that his pure and straightforward
patriotism would be proclaimed to the whole world.

Then the day arrived ! Wandsworth, the town which
was now to be cut clean in two by a vast abyss, while
a large portion of it had disappeared into that abyss,
was en fete. The river beyond swarmed with boats of
all kinds (for the rush of water was not to be so sudden
as to cause any serious difference to the river that day).
Flags flew from every suitable point. Strains of music
and joyous voices rose from all around. The only
sombre-looking spot was the vast brown excavation ex-
tending southward as far as the eye could see, on which
all the interest hinged.

As the church bells slowly boomed forth the mid-
day hour, bands struck up the National Anthem, and
the roaring of thousands of throats rose in their loyal
greetings to the occupants of a Royal carriage as it
raced Into the great enclosure surrounding the spot
where the puny work was about to take place which

314

KNOWLEDGE & SCIENTIFIC NEWS.

[December, 1905.

would represent the first cutting away of the enormous
dam.

And there were two other figures which attracted the
attention of the thousands of onlookers. One was the
man to whose master-mind this huge undertaking was
due. Petty squabblers could, on an occasion like this,
be forgotten or set aside, and the general public only ,
recognised in that figure the founder of another prop, j
another addition to our Empire, of more importance |
perhaps than the settling of an extensive new Colony I
or the discovery of unknown territories, since the popu-
lation of the reclaimed area was sure to become very
shortly equaj to that of a large Colony.

But what was the other figure? Equally fascinating
to the public eve, and yet for a very different reason.
The one with the sagacious, clear mind, sharp even to
cunning, large minded even to unscrupulousness ; the
other innocence personified — a simple but extremeh'
prettv little girl. Miss Libertia Tush. .All eyes were
drawn to gaze upon the charming childish figure, clad
in white, with the huge bouquet, which she so grace-
fully deposited in Royal hands.

The sun broke forth in all his splendour, and cheers
rent the air as the first trickle of water passed from
the Thames into the new cutting. Everyone was
enthusiastic and highly pleased. -All except one, and
that was the very person who should have been
elated above all others at seeing the work of his
brain brought into activity, and to realise that his
ambitious dreams were actually accomplished ! But
his expectations in other lines had not been realised.

The highest in the land have to be guided by the feel-
ings of the majority of their subjects. This great cere-
mony had very nearly to take place without that royal
presence, the request for which had only been granted
after special pleadings. The founder and chairman
had exp>ected honourable recognition of his great work

before this; but nothing of the sort, no kind of en-
couragement had been held out to him, and he had only
hoped that the announcement of his reward had been
deferred to the final moment of the opening, then did
he expect to be the recipient of such honour as would
have for long thrown off the scurrilous and menacing
attacks that had Ixjen made by envious persons as to
his private financial transactions. But nothing had
come of it ! He had been received by Royalty with
marked coldness, even though the eyes of the whole
Court were attracted to Libertia, and had it not been
for the ardent admiration shown for his little daughter,
an awkward scene might have ensued. \\'ith the
audacity acquired by one supreme in his own line, and
with the anger of Ix'ing foiled in his ambitions, he had
actually enquired point blank whether he would be
likely to receive such recognition from the hands of his
august visitors as might be commensurate with the
work which he had now brought so near completion.
What was intimated in reply was nothing more nor less
than a snub. He, Cornelius J. Tush, snubbed ! It
was more than he could stand. " Your bloated aristo-
crats could go to — where they like. What cared he
for the beastly rags fluttering overhead ? They could
have the Royal ensign flying there, but the Stars and
Stripes must come down. He wasn't one of that fat,
phlegmatic, apoplectic John Bulls. No, thank good-
ness ! " And so Tush turned on his heel, determined
once and for ever to sever his whole connection with
these schemes for the improvement of a " foreign
town."

And so he did. His whole financial interest in the
affair became transferred to other hands, and though
his name, for various reasons, was still retained on the
company's books, he, with his wife and child, returned
to re-found their home in the States.
(To he continued.)

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Full text of "Knowledge. v. 1-40; Nov. 1881-Dec. 1917"

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