v^ ^'

Practical Aerodynamics and the Theory

of Aeroplanes.
Features of the Earth and Moon.
Maximum of Mira Ceti.

The Late Miss Agnes M. Clerked

A Fish out of Water.

Basis of the Will.

The Face of the Sky for February.

NOTES. — Astronomical, Botanical, Chemical, Geological, Ornithological, Physical, Zoological.
PHOTOGRAPHY. MICROSCOPY. REVIE'WS. &c., &c.

A}
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KNOWLEDGE & SCIENTIFIC NEWS.

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RECENT ADVANCES IN THE STUDY OF
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The past few years have been marked by advances in Biology scarcely less extensive than those made by Physical Science within
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SCIENCE PROGRESS IN THE TWENTIETH CENTURY.

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The Economics of University Education. Sir .\rthcr
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Some Recent Developments of the Electrolytic Dissocia-
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The Decadence of Ammonites. Felix Oswald, D.Sc.
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The Rusting of Iron. \V. fi. Davis. Illustrated

Some Aspects of " Double Fertilization " in Plants. Ethel
N. Thomas, D.Sc.

Recent Work on Protein=HydroIysis. J. Reynolds Green-,
Sc D., F.R.S.

A Year's Work in Vertebrate Palaeontology. R. Lvdekker.

The Behaviour of Over-Strained Materials. .\. O Rankine,

B.Sc. Illustrated.
The Principles of Seed-Testing. T. Johnson. D.Sc.
The Chemistry of Indiarubber. Samuel S. Pickles, M.Sc.
Marcel Nencki, 1847=1891. S. B. Schryver, D.Sc, Ph.D.
Recent Advance in the Study of Fungi. .\. Lorrain

Smith, F.L.S.
The Danger of Flies. Arthlr E. Shipley, M .\. D.Sc,

(Princeton^ F.R.S.
The Reform of the Medical Curriculum— A Problem in

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IV.

KNOWLEDGE & SCIENTIFIC NEWS.

[February, 1907.

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KNOWLEDGE & SCIENTIFIC NEWS.

V.

V CONTENTS, v

Practical Aerodynamics and the Theory of Aero-
planes. By Major B. Baden-Powell .. .. .. 25

Queens College Horn .. .. .. .. .. 26

Features of the Earth and Moon — Volcanic Forma-
tions (;;//'/i iiluslyations) .. .. .. .. .. 27

The Bogoslofs and Earthquake Disturbance . ..30

The Late Miss Agnes M. Gierke [with poidait) .. .. 31

Photography : Pure and Applied. By Chapman Jones,

F.I.C., F.C.S., &c 32

Maximum of Mira Ceti. Hy P. M. Ryves (with diagram) 33
The Bride-Stones — Cleveland Hills. By E. J. Sumner,

B.Sc. (with illiistialioii) .. .. 34

A Fish Out of Water. By Fellx Oswald, D Sc. (with

illustiations and diagrams) .. .. .. .. .. 35

Basis ofthe Will .. 37

Notes. — Astronomical. By Charles P. Bdtler, A.R.C.Sc.

(LoND.), F.R.P.S 38

Botanical. By G. Massee 39

Chemical. By C. Ainsworth Mitchell, B.A. (Oxon ),

F.I.C 39

Geological. By Edward A. Martin, F.G.S. .. 40

Ornithological. By W. P. Pycraft, A.L.S., F.Z.S.,

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Physical. By Alfred \V. Porter, B.Sc. .. .. 41

Zoological. By R. Lydekker .. .. .. .. 42

Correspondence (with illustration) .. .. .. .. 43

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Microscopy. Conducted by F. Shillington Scales, B.A.,

FR.M.S 46

The Face ofthe Sky for February.

F.R A.S.

By W. Shackleton,

48

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Knowledgfe 6t Scientific News

A MONTHLY JOURNAL OF SCIENCE.

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

Vol. IV. No. 2.

[new series.] FEBRUARY, 1907.

[Entered at "i
Stationers' Hall. J

SIXPENCE NET.

CONTENTS.- See page V.

Pra.cticacl AerodyrvaLmics
And the Theory of Aeroplanes.

Bv Major B. Baden-Pow ell.

Introduction.

Just now the subject of aerial navig-ation has been
prominently brought before the public. .'\ wide interest
has been aroused, and people generally are beginning to
see what a vast future there is open to a machine able
to traverse, surely and safely, the realms of blue.
.Although I am one of those who always prefer fact to
theory, and though most of the important inventions
which have aided human progress have not sprung from
the mathematician's brain, I quite realise that a certain
amount of study of the principles underlying any such
subject is most necessary to one who would add any
important work towards the conquest of the atmo-
sphere.

The air, then, and the effects of its pressure on bodies
moving through it, demands our earnest attention.

.Air may seem a light, subtle fluid. If we pass our
hand through it we notice very little resistance to the
motion, and we mav wonder how it is possible to
utilise this verv vielding medium to support the heavy
weight of a human body or metal machinery against
the force of gravity. From a mechanical point of
view it is just the same whether a body be pushed
against the air, or the air blows against a stationary
body. Yet we all know what air, when in motion at a
great speed, may effect. We know that if the wind be
Jilowing with the force of a gale — perhaps 60 or 80
miles an hour — it is capable of exerting a ver\' great
pressure, especially on suitably disprscd surfaces. We
know well enough that when out on a windy day, an
umbrella held even with its convex side to the wind, is
sometimes most diflieult to hold, and that directly it is
turned so as to present a concave surface it is immedi-
ately blown inside out, or if made strong enough to
resist this action, would pull with such force as to be
almost impossible to hold. This enables one to realise
what mav he effected bv making an ajiparatus to travel
very rapidiv through the air.

It seems probable th:it an ordinary umbrella (suitably
strengthened) held so as to let a very strong wind strike
underneath it, would pull so hard as to be almost
capable of lifting a man off his legs, momentarily, at
least. This fact hardly seems extraordinary, yet if we
imagine a flying apparatus only ns big as an umbrella
progressing at 40 or 50 miles an hour through the air,
it would surprise most of us to think that it was capable
of raising a man.

This enables one to realise that if only we can get
the pmi'cr, propcrlv applied, n vcrv small ajiparatus
may be sufficient for our ]nirposc — and, if a very large

aeroplane be used, what great lifting power is to be
derived from it.

This subject, though likely, as already intimated, to
become one of very great importance, yet is one that
has received but comparatively little attention among
scientific experimentalists.

Langley, in the introduction to his book, " Experi-
ments in Aerodynamics," published in i8gi, says : " In
this untrodden field of research '. . . I think it safe
to say that we are still, at the time this is written, in a
relatively less advanced condition than the study of
steam was before the time of Xewcomen."

Xo complete treatise on the subject exists. .All the
information that is available has to be extracted from
works dealing with aeronautics (mostly historical),
hydrostatics, and pneumatics, and from the various
technical papers which have been compiled on certain
definite branches and on results of particular series of
experiments. The following is a general review of the
whole subject gathered from these sources. It does
not pretend to be complete or exhaustive, but it is
hoped that it may be of assistance to those anxious to
get an idea of the science, and who are unable to wade
through the various sources of information enumerated.

I propose treating of the subject in the following
order. It will be necessary first to brieflv refer to the
theory of the balloon, and ascent by reaction of a fluid,
and then to get on to the main subject of aeroplanes
and apparatus working on kindred principles.

This latter subject must again be subdivided into air
pressures acting perpendicularly on a plane surface,
air pressures on inclined plane surfaces, the effect on
the back of such planes, and pressures on curved sur-
faces moving through the air.

Finally, to consider the combined effects on various
shaped bodies in practice, the flight of birds, and the
theoretical action of aerial screw propellers.

In considering the different methods possible for the
attainment of artificial flight — which is practicallv
synonymous with means of overcoming the force of
gravity — there are three principles to be taken into
account : —

(i) Displacement. — By displacing a bulk of air bv a
body of less total weight than that air. Under this
head would be included hot-air balloons, gas balloons,
and the theoretical, if impracticable, vacuum balloon.

(2) Dcnvmcard Reaction. — By the reaction of a fluid
driven forcibly downwards. Such is the principle of
the rocket.

(3) Sub-Pressure. — Deriving support from the pressure
of the air on the under surface of a body driven through
it. This would include not only what is understood bv
the term ".Aeroplane," but also revolving aeroplanes
or lifting screws, and wings and paddles striking the
air downwards. I'nder this heading, too, must come
the wind-borne soaring birds and thistledown.

.As regards the first of these methods wo need but
briefly go into it, since the subject of ballooning is
rather beyond our present scope.

26

KNOWLEDGE & SCIENTIFIC NEWS.

[February, ii/O?-

If a t;i\'fii voliinu' of :iir \n- (lisplact'd and tin- space
filled by a vessel iiillated with some suljstanee lijihter
than air, such as Iiydroijen, coal gfas, steam, or air
rendered less dense by beins^ heated, then, if tlic con-
taining vessel is not too heavy the whole will rise in
tlie air. This is in obidii'nce to well-Unowii laws. '1 he
heavier particles of air will slip under the lii^hter Ixuly
and buov it up, just as water when poured into a basin
would slip under and buoy up a cork lyini; in the basin.
That air has definite weight can easily be proved by
carefully wei.y:hint,'- a bottle which has been exhausted of
air, and weii;hintr it a.ij'ain when air is admitted to it.
In this way air is found to weifrh .075 lb. per cubic
foot, or 1,000 cubic feet will wcis:h 75 lbs.

Hydrogen gas can l>c weighed in the same manner,
and i.s found to be .005 lb. per cubic foot, or 5 lbs. for
1. 000 cubic feet. Coal gas varies, but may average
about 35 to .JO lbs. per 1,000 cubic feet. Steam, which
has actually been applied to ballooning, varies accord-
ing to its temperature*. .As regards heated air, what is
known as Ch.irles's law shows that a given volume,
under constant pressure, increases with temperature
.00367 times its bulk per degree Centigrade, or .002
Mtt) pei" degree Fahrenheit. If, then, the air in a
balloon can be raised by loo" F., one-fifth of its weight
will be exj>elled; that is, each cubic foot will then weigh
f of .075, or .06 lb., or 1,000 cubic feet will weigh 60
lbs. instead of 75.

The.se principles are often overlooked by unscientific
inventors, who sugg-est adding a small balloon to aid
in lifting their apparatus, or who anticipate a hope of
finding a gas lighter than hydrogen.

One F. Lana, in 1670, was probably the first to
suggest the idea of a machine on this principle, but his
suggestion was to exhaust the air from large copper
globes, ignoring the practical fact that the pres.sure of
the atmosphere would crush in any such vessel as soon
as a very small quantity of air had been extracted from
it.

The second methcwl, though interesting as a specula-
tive suggestion, seems hardly likely to prove of prac-
tical utility, for a man-carrying machine.

Rocket.s are wcW known. They are practically useful
for many special purposes, but are extremely wasteful
of fuel, and, therefore, short-lived. Steam jets striking
downwards have been suggested.

Mr. H. Wilde, F.R.S., conducted a number of ex-
periments at one time* in order to ascertain what force
could be practically applied with this idea. He tried
high pressure steam and compressed air through orifices
of manv various forms, also explosions of gas mixed
with air and ignited by electric sparks He, however,
sums up the whole matter by saying : " The results of
all these experiments on the discharge of elastic fluids,
made with a view to the possibilities of aerial loco-
motion, were purely negative, and proved decisiyely
that the solution of the problem was not to be found in
that direction." It occurs to me, though 1 have not
actually tried the experiment, that liquid air might be
used in this connection. A vessel of liquid air in
ordinary atmospheric circumstances is practically
equivalent to a vessel of water placed in the middle of
a furnace. The liquid air in the one case and the
water in the other are boiling hard and rapidly
evaporating into air or steam respectively. So that by
employing this method we practically have a steam
boiler exposed to a comparatively very high temperature
(that is the difference between that of the liquid and

* " On Animal Locomotion." by Henry Wilde, F.R.S. Vol.
xliv. No. II. of the "Memoirs of the Manchester Literarj' and
Philosophical Society." 1900.

that of the surroimding atmosphere), yet without any
fuel or apparatus for binning fuel. .\ great pressure
may thus be obtained with but little weight, and it
could, therefore, be made to a.sccnd. It is true that
this action may be very wasteful and would not last
long. Still, as an experiment, it might be interesting
to see a vessel rise in the air by this novel means.

It may be added th:it though a continuous stream
issuing from a jet may, theoretically, be wasteful of
power, it would probably not Ik- dillicult to make the
jet intermittent, or, by progressing rajiidly in a hori-
zontal direction, to cause it to act continu.illy on fresh
air.

The third principle, which promises the most practi-
cal results, and is a much larger subject, wc must leave
for a future article.

(7V) he colli hiucd.)

Qvieei\'s College Horn.

In the Buttery of Queen's College, Oxford, is preserved
one of the city's greatest curiosities. It is an old
drinking cup presented to the College by Philipjia,
Consort to Edward III., more than five hundred years
ago, from whom it took its name. In shape it re-
sembles a horn; it is made of polished horn, brown in
colour, and richly decorated in silver-gilt. It is one
foot eight inches high, and the outer curve from the

SUetcUfil hi/Rtiiry K. Crapper, Qufcn's CoUcga Lodge.
Horn in the Buttery, Queen's College, Oxford.

extreme points is forty-one inches. It will hold two
quarts.

On the lid is a silver eagle of curious workmanship,
and the whole is supported by eagles' claws.

An eagle was the crest of the founder of the College,
■vobert de Eglesfeld, Confessor to Oueen Philippa.
This cup is still used on " Gaudy " day, and is handed
round after dinner. The contents consist of
" Chancellor," a strong beer brewed bv the College —
sherry and brandy flavoured with pine-apple.

February, 1907.]

KNOWLEDGE & SCIENTIFIC NEWS.

27

Fea^tvires of the CoLrth
8Lnd Moon..

Volca-rvic FormaLtions.

that matter expelled from a crater vent could be thrown
very much farther or very much wider than is the case on
this planet. But, says Professor Pickering, we are really

Some fascinating speculations on the formation of the
Earth's crust emerge from the publication among the
Memoirs of the American Academy of Professor W. H.
Pickering's " Lunar and Hawaiian Physical Features."
The physical features of the island of Hawaii which Pro-
fessor Pickering has photographed and investigated are
its huge craters and lava plains and lakes ; and he has
noted a similarity m their formation and contours with
the very much larger craters of the Moon. The Earth
and the Moon being supposed to have a common origin,
and tj have once been part of the same mass, it would
appear not unreasonable to expect that their exterior
features would bear some resemblance. But as Professor
Pickering observes " the lunar surface presents such a
strong contrast to the more thickly populated portions of
the Earth that little resemblance between them can be
traced. Even those of our volcanic regions which have
been most extensively studied show little analogy to the
Moon."

The only Earth cra'ers which bear a colourable re-
semblance to those of the Moon are the craters of Hawaii,
with which Professor Pickering in the work before us
compares them ; and from a consideration of the
Hawaiian craters his theory of the reason for the differ-
ence between lunar and terrestrial formations, is chiefly
drawn. The enormous discrepancy in size between
the craters of the Moon and those of the Earth is some-
times attributed to the fact that the force of gravitation
at the surface of the Moon is but one-sixth as great as it
is on the Earth. But this theory will not do ; although
if the lunar craters had been due to explosions of steam,
as the Earth's explosive volcanoes are, one may grant

Pjg. 2.— Kies and Mercator.

trying to compare objects formed under
conditions. " The larger craters on the
existence when the thin solid crust cov
interior was, owing to the solidification

HiK. 1. Interiur ul Itulcnkald.

entirely difTerent
Moon came into
ering the molten
and contraction
of the crust, much
too small to con-
tain the liquid
material. The
craters we re
therefore formed
by the lava burst-
ing through the
crust, and so re-
lieving the press-
ure." In other
words they were
overflow erup-
tions.

Then, at a se-
cond period in the
Moon's history,
another form of
crater, or rather
another form of
volcaniceruption,
came into play.
Tiie crust of the
Mixin had thick-
ened ; and the in-
terior regions, by
cooling, shrank
away from the
solid shell, as a
drying walnut
does. The solid

28

KNOWLEDGE & SCIENTIFIC NEWS.

[February, 1907.

shell, being insufficiently supported, caved in liere
and there, permitting the great fissure eruptions which
produced those great tracts which we call the lunar seas.
These extensive outilows ol la\a dissolved the original

Fi^. 3,~Bullialdus.

solid shell whenever they came into contact, obliterating
its features. The same obliteration of smaller craters (on
a much reduced scale) can be perceived in Hawaii. In
all probability the same thing, Professor Pickering sug-

¥t'

\y^-

gests, tODk place on our own Earth on a larger scale
instead of on a small one. The inner core of the Earth
shrank still more from the cooling and hardening outer
crust ; the resulting cataclysms were still greater and
more destructive; and through great fissures there were
enormous outllows of lava and molten rock, now recog-
nised as "archaic rocks," which conipleteiy dissolved and
destroyed the gigantic blister craters which once studded
our globe.

The volcanoes of Southern l£urope, which are those
most completely studied, have little in common with those
of the Moon. In the case of the volcano of Vesuvius, for
example, a high truncated cone has been built up by
mild eruptions of steam and cinders, sometimes alternat-
ing with lava. At long intervals violent explosions
occur, which sometimes blow away a large portion of
the summit. Such an explosion occurred when Pompeii
was overwhelmed, and it was repeated on a minor scale
last year. The most violent explosion of the kind of
which we have any record was that which occurred not
at \'esuvius but at Krakatoain 1883. Nothing whatever
of that kind is perceptible among the discoverable craters
of the Moon. In volcanoes of the engulfment type, as
opposed to the explosive type, comparatively little steam
is evolved ; often there is no exterior cone, and the craters
enlarge quietly by the cracking off, and falling in of their
walls. This species of crater is to be found in Hawaii,
though the Hawaiian structures are on a comparatively
small scale, the largest of them being one-hundredth the
diameter of a lunar crater.

On the great seas or vuiyia of the Moon, secondary
engulfment craters were formed ; and of these Pessel,
which is about twelve miles in diameter, is a large and
well-known example. There are no great craters of that
size on the Earth to compare with it ; all the Earth's
largest craters being of the explosive type.''' At
Hawaii, with the exception of the three great craters of
Haleakala, Mokuaweoweo, and Kilauea, few of the crater
pits exceed half a-mile in diameter ; but it is possible to
compare these with those of the Moon, in spite of the

discrepancy
of size. On
the Earth at
present, the
cooling pro-
cessas wit-
nessed at
Hawaii al-
ways inter-
venes before
great size
IS attained.
Formerly,
the lava was
hotter when
it issued
from the in-
terior; more-
over, the

Fij;. 4. — Kauhaku, Molokai.

* The three
greatest cra-
ters on the
liarth, about
fifteen miles
in diameter,
occur in Kam-
ch a tka, in
Japan, and in
t lie I'h i lip-
pines. All are
Lf ihe explo-
sive type.

February, 1907.]

KNOWLEDGE & SCIENTIFIC NEWS.

29

solid crust resting on the liquid mass was thinner, so that
the channel communicating with the three reservoirs of

Fig. 5. — Lava Lake in Kilauea

molten lava was shorter and wider, thus offering a freer
passage to the liquid flow.

Professor
Pickering di-
vides terrestrial
craters into
three classes,
according to the
materials of
which they are
composed.

(i.) Tufa cones
of hardened vol-
canic mud.

(ii.) Cinder

cones.

(iii.) Lava

craters.

It is this third
class where
steam or water
is less involved
in the process
of eruption
which most
resembles what
we find on the
Moon.

This class may
be again divided
into four sub-
classes accord-
ing to the shape
of the craters—
(f) lava rings, and (d) lava bowls. Taking the first of

them (a), the lava cones, these often emit vast volumes
of lava which may extend for miles in broad streams.

The second
sub-class (6), the
lava pits, are by
far the most
numerousgroup
and are widely
distributed
through the
Hawaiian Is-
lands. They
have no outer
slopes what-
ever, consisting
simply of a pit
sunk in the
ground. Their
inner walls are
sometimes ver-
tical, sometimes
inclined, and
descending with
a steep slope to
a flat floor.

The lava
rings (f ) are the
rarest type in
Hawaii, and
resemble the
larger craters
found on the
Moon.

The lava
bowls (d) differ from'them in that^the bottom, instead of
presenting a well-defined, flattened floor, is concave, the

Pig. 6. Lava Lake in kilauea.

namely, (a) lava cones, (b) lava pits.

curvature being continuous with the walls. They are iden-
tical in appearance with most of the smaller lunar craters.

30

KNOWLEDGE cS: SCIENTIFIC NEWS.

[Fedruaky, 1907

With these preliminary remarks we may introduce
some of Professor Pickering's photofjraphs of Hawaiian
volcanoes. Mud volcanoes and cinder volcanoes are repre-
sented in Hawaii. Tlie Diamond 1 lead crater isof volcanic
tufa, and bears an exterior resemblance to the craters of
the Moon ; but its floor is at a higher level than the
exterior plane and its outer slope steeper than its inner
one, so that this crater, toj;ether with all the cinder
cones, may be dismissed as having no known counter-
part on the Moon.

The Hawaiian lava craters, however, on the other
hand, present a close resemblance in many respfctsto
lunar formations. The first subdivision (a), the lava cones,
are most strikingly represented by Mauna Loa, by far
the world's largest volcano. Us base lies 15,000 feet
below the level of the sea. Nevertheless, its summit

Fig. 7.— Scblckard and Pbocylidcs.

crater is so large compared to its depth that photography
could not very well show its characteristic features, and
accordingly Professor Pickering chose a smaller example,
a small lava cone in Haleakala as the typical example of
this form of crater.

The terrestrial tall volcanic cone, with the compara-
tively minute crater at the top, was supposed to be
absent from the Moon. But a recent examination of a
lunar photograph taken at the Yerkes Observatory by
Professor Ritchey shows that there are some small
examples. One of these is probably visible in fig. 3,
which is a lunar photograph of Kies and Mercator.
Between them is to be seen a small cone with a minute
crater at its summit. It is not unlike Vesuvius in size
and shape.

We next come to lava pits (b). In the lunar photo-
graph of Bullialdus is a pair of coneless lava pits, just
above the huge crater. A few other very minute pits
are shown on the photograph, but all the larger ones
have cones.

In Fig. 4 we have" a small terrestr^il pit of this type-

It is known as Kauhaku ; and has no exterior cone
whatever; it is simply a hole in the ground.

Great attention was bestowed by Professor Pickering
on the method of formation of crater rings, the third sub-
division of lava craters ; and he experimented with iron
slag to obtain object lessons of the methods of formation
of craters. But the great central pit of Kihuiea, Hale-
maumau, supplies object lessons on a larger scale. When
Ilalemaumau is really active, the sight is said to be grand
beyond description. Lakes of liquid lava occur both
within and without it. Numerous lire fountains from
10 to 50 feet in height play over the surface of these lakes.
At times the surface solidifies, then suddenly a crack will
run across it, and in a few minutes the who'e solid
material will break up into separate cakes, which will
presently turn on edge and sink beneath the surface of
the lake. These lakes are specially interesting, since
about them are found crater rings which seem 1 1 be
analogous in appearance to the larger cratir formations
in the Moon.

In itS, o the pit overflowed, the lava pouring down and
filling a neighbouring dejiression. At the time of an
eruption such as this the lava rises, overflows, and cools,
thus forming a raised rim or circular dam. Such a rim
is shown on a large scale in figs. 5 and 6, the cakes of
lava appearing like broken cakes of ice. In fig. 7 is
shown a portion of the Moon near the limb so as to present
the craters obliquely. It will be noted that the two large
craters there depicted, namely, Schickard and Phocylides,
both present a form similar to the craters of Halemau-
mau. The chief one, Schickard, measures 134 miles in
diameter.

(To be continued.)

The Bogoslofs and Earthquake
Distvirba.nce.

Mr. V. A. Black writes in regard to the article in last
month's " Knowledge " on the Bogoslof Islands : —
Whether there is any direct connection between the
birth of this island and the recent severe earthquakes at
San Francisco and Valparaiso — not to mention the
activity of Vesuvius in our own continent — can only be
conjectured. The new- island would seem to be about
3,500 miles from Valparaiso, and about 1,500 miles
from .San Francisco. It certainly cannot be overlooked
that the emergence of this island synchronizes with the
occurrence of severe earthquakes on the eastern shores
of the Pacific, thoug"h at a g^reat distance from the posi-
tion of the island, just as the sudden appearance of
firevwingk synchronized with the occurrence of earth-
tremors and eruptions in Alaska, and with the terrible
eruption in Krakatoa. Krakatoa is situated in the
neighbourhood of the south-western shore of the Pacific,
and, like San Francisco and \'alparaiso, it is at a very
great distance from the position of the Bog-oslof Islands.
Whether the emergence of the first of the three islands
also synchronized with similar phenomena is uncertain.
The appearance of this new island emphasises what
we are often apt to overlook, notwithstanding our
knowledge of the volcanoes and geysers of Iceland, at
the Arctic Circle, and of the activity of Mount Erebus,
far within the Antarctic Circle. That is, that in high
latitudes, as in low latitdues, subterranean forces are
still actively at work, and that terrestrial disturbance,
in the form of earthquake or volcano, in one reg^ion
mny, not improbably, be accompanied by sympathetic

February, 1Q07.]

KNOWLEDGE Sc SCIENTIFIC NEWS.

31

activity in other reg-ions, especially in regions of
volcanic origin or geological weakness. It is an ascer-
tained fact that the vast hollow of the Pacific Ocean is
encircled in all latitudes by a ring- of volcanic foci,
whether active or dormant.

It is interesting to notice that the situation of the
.Meutian Islands, is, in certain respects, very similar to
the situation of the British Islands, so that geographi-
cally, they represent our islands on the other side of
the Northern Hemisphere. The latitude of Bogoslof
proper is about 54° N., which is about the latitude of
York. Assuming-, as is indicated by the information
received, that the new island is about 120 miles farther
north, its latitude will be rather less than 56° N. This
is virtually the latitude of Edinburgh, the latitude of
the summi't of the Calton Hill being 5.^° 57' 23" N. In
longitude the .iMeutian Islands extend a great distance
both east and west of the i8oth meridian. That
meridian, as every schoolboy knows, is simply an ex-
tension of the meridian of Greenwich, the Greenwich
meridian and the iSoth meridian forming together one
great circle around the earth passing through both
Poles.

The Bogoslof Islands themselves are, however, some-
what to the east of the 180th meridian, their longitude
being- about 168° W.

The correspondence in the latitude and the similarity
in the longitude of the British Islands and the Aleutian
Islands are rendered the more noticeable in view of the
relative position of each group of islands to the great
continents. The British Islands, including the neigh-
bouring small islands, form (as regards longitude) an
archipelago lying between the continent of Europe and
the continent of Xorth ."Xmerica; while the Aleutian
Islands form an archipelago lying between the continent
of North .America and the continent of Asia. The
British Islands, however, are a consolidated group,
while the .Meutian Islands are a fragmentary chain.
The British Islands extend chiefly northward and south-
ward, while the Aleutian Islands extend eastward and
westward. The total area of the .Aleutian Islands is
estimated at about 6,391 square miles, while the United
Kingdom has an area of 120,677 square miles. Of
course, the area of each of the three islands forming
the Bog-oslof group is quite trifling, probably not more
than two or three square miles, if so much.

The resemblance which the geog-raphical position of
this insig-nificant archipelago bears to the geographical
position of our own country bring-s into more striking
contrast the tremendous difference which, in almost
every other respect, exists between the British Islands
and the .'\leutian Islands. Although the latitude of
the Aleutian Islands is similar to our own, the climate
is very different, being more like that of Iceland than
that of Great Britain. The mean temperature in Una-
laska is 38.3° P., and, as is usual in the case of small
islands some distance away from any large extent of
land, the range of the temperature is not excessive.
In the British Islands the soil generally is good, and it
is highly cultivated; in the .'\leutian Islands the land
generally is rocky and barren, and fishing- and sealing
are almost the sole industries. In this country the
population is dense, and the people arc advanced in
civilisation; there the population is scanty, and the
pt'ojile are but partially cixilised. The crow-ning feature
of the strange contrast is supplied by Nature herself.
The complement of the British Islands, from a geo-
logical point of view, was made up untold centuries
;igo; while the .'\leutian Islands are still on the increase,
having- grown by three since the time of the French
Re\'ohition, b\- two since the battle of Tel-el-Kebir.

The La.te Miss Agnes M. Gierke.

With the deepest regret we have to announce the death
of Miss .Agnes Mary Gierke, which took place on Sun-
day, January 20. Miss Gierke was sixty-four years of
age.

In the columns of " Kxowledge," to which Miss
Gierke was so often an inspired contributor, it is hardly
necessary to speak of her commanding: gifts as an ex-
positor of science; it is hardly more necessary, in ad-
dressing an audience which embraces so many astro-
nomical readers, to refer to her position in the
astronomical world. It was said by an appreciative
critic of her work, in one of the obituary notices that
have already been written concerning her, that she was
not a practical astronomer in the ordinary sense. That
is quite true; and it is probably also true that the ab-
sence of the hard, grinding, day-by-day study of details
whi"h are an indispcn'-'ililc part of the equipment of

rUiiUiijTajih bij Elliot tt Fry.
The Late Miss Agnes M. Gierke.
(Reproduced by permission of the '^ Daily Graphic.*')

those who laboriously disclose the truths of science may
detract from the lasting value of some of her work.
But these qualities, the absence of which mars the man
of science, may make the philosopher; and, as the hand-
maiden of astronomy, as one who held a lamp aloft
that others might examine its discoveries and its
theories, Miss Gierke, in our belief, stands unrivalled
in her day. We may enumerate some of her works to
show the solidity of what she did :— " Problem.s in
Astrophysics," "A History of .Astronomy in the Nine-
teenth Century," "The .System of the Stars, Fhe

Herschels and Modern .Astronomy," " Modern Cos-
mogonies " (which appeared in "'Knowledge"), and
unnumbered articles, essays, and reviews. But the
enumeration conveys little idea of the work that she did;
for she brought to bear on the systematisation of such
subjects as therein are indicated an unrivalled power of
interpretation. We gnitefully acknowledge the justice
of the appreciation iii the Times:—" No worker in the
vast field of modern sidereal astronomy opened by the
genius of Herschel and greatly widened liy the apjilica-
tion of the spectroscope to the chemical and physical

32

KNOWLEDGE & SCIENTIFIC NEWS.

[pEnRUARY, 1907.

prohlcms of llii' univtTSc l:irki-il ihic rccoijiiilioTi by Miss
Ck-rku, who ])(Mri>rnu'ci as it srcnu'ii no oIIut wiiti-r
coiiki li;i\L' (ii)iu' the work ol colhition and intirpri'la-
tion 1)1 this I'lioniKuis mass of now material, t-viT point-
iiij;' the wav to new liokls of invcstit;atioii, oltcn hy
one preynanl siiijt^cstion swoipini^' asiik' a w hok' slu'af
of tentative conjeetiires and indiratiiit;, if not llie true
line — for in many eases the truth is yet to seek — at
least a plausible and seientilie line well worth pur-
.'Uiini;'. " There is one other point on whieh we should
like to dwell. No writer of her time had a juster sense
of style. In a nation which consumes lietion as its
staple liter;irv food, the quality of literary style when
apparent in other kinds of literature is likelv ti> be
o\erlo!)ked. lUil Miss Clerke ]5ossessed it in the
hitjhest desjree. There is a passaiifc in one of the eha]i-
ters of .Modern Cosmogonies, "'The Inevitable lather,"
whieh h.is always seemed to us a model of style, eleijant
without alTi'rtation, fastidious without sacriliee of mean-
ini;, iiunitablv riijht in its ehoioe of words. W'e quote
it : —

"To the very brinl< of that mysterious oce;m the
science of the twentieth ccnturv has hroui;ht us; and it
is with a thrill of wondering' awe that we stand at its
verge and rurvcy its illimitable expanse. 'The glory of
the heaxcns is transitory, but the imjialpahlc, invisible
ether inconceivably remains. .Such as it is to-day, it
idready was when the Fiat Lux was spoken; its be-
ginning must have been coeval with that of time.
Xotbing or c\erything- according to the manner in
w hirh it is accounted of, it is evasive of common notice,
while obtrusive to delicate scrutiny. Its negative
qualities are numerous and baffling. It has no effect
in impeding motion; it docs not perceptiblv arrest, ab-
sorb, or scatter light; it pervades, yet has (apparentiv)
no share in the displacements of gross matter. Look-
ing, however, below the surface of things, we find the
semi-fabulous quintessence to be unobtrusively doing
all the world's work. It embodies the energies of
motion; is, perhaps, in a wry real sense, the true
primiim mobile; the potencies of matter are rooted in
it; the substance of matter is latent in it; universal inter-
course is maintained by means of the ether; cosmic
inlluenccs can be exerted only through its aid; unfelt, it
i.s the source of solidity; unseen, it is the vehicle of
light; itself non-phenomenal, it is the indispensable
originator of phenomena. .\ contradiction in terms, it
points the perennial moral that what eludes the senses
is likely to be more permanently and intensely actual
than what strikes them."

'That is not fine writing; it is literature; and w-hatever
Miss Gierke's place in the history of astronomv, it will
be a high one in the history of letters.

E. S. G.

In Memoriam— Agrnes Mary Clerke.

I Icrs was the part to glean the scattered grains
Of truth, which reach us from the starry field;
To weigh results which calculations yield,

.See where they tend and gather up the gains

Of many a night-long watch. .She remains

The mistress of a style, v.hose greatness sealed
It to sublimest science, which revealed

Deep study, and far-reaching thought contains.

And she who, judging the cosmogonies.

Marked what they lacked, dimly preceived how
A Power outside of Nature guideth all

By ordered paths — a Power which vivifies

And upwards leads. She has g:onc from us now,
.■\nd from her eves earth's darkening glasses
f""- ' T. K. Hhatii, F.'r.'A.S.

Photography.

Pure arvd Applied.

By Chapman Jones, I'M.C, I'.C.S., &c.

M \^^ of the (le\elo|)crs that are remark-
Hnersetic ,^,^j^, ^^^^. ^^^^.^^. ^.,^^. ^ .,„j ,-apiditv of
Developers. _. , ,, , ' . .

action, such .is metnl and paramido-

plvcnol (11k' latter is the acli\r agi-nt of ni<linal and
uiial) are, chi'inicall) s|X'aking, basic substances, ;ind
are supplied in combination with acids, as salts, becau.se
the free bases are ton unstable' for pi;ictical purposes.
'They are g:'nerall\- sold in coiiiliination with hvdro-
chloric acid or siilphiirie acid, and when dissoKrd with
alkali gi\e ri.se to alk.dinc chloride or sulphate, which
mav ha\o, and, doubtless, sometimes decs have, a re-
tarding action. Messrs. Lumiere and Sevewetx have
sought to overcome this dr.-iwback without the loss of
stabililv in iIh' solid material, by combining the bases
with sulphurous acid instead of sulphuric or hydro
chloric, SOI that the alkali in the mixed dexclopcr shall
give its sulphite instead of its sulphate or chloride. .Vs
alkaline sul|5hite is always added in considerable
f|iKinlilies to such developers, the small amount so
pnxluced has no' appreciable effect. 'They report that
the products "are stable enough for commercial purposes,
and behave in developers as if the free bases had been
used. The compounds do not appear to be very defi-
nite, as they contain several molecules (six to ten) of
the organic base to cne of sulphurous acid. Experience
alone can show whether these new compounds will
prove advantageous, and we certainly should feel
grateful to the.se investigators for working at the sub-
ject. Hut as alkaline sulphates in small qu.antities do
not notably retard development, and the simultaneous
reduction in the restrainer ;ind alkali is often of \ery
doubtful benefit, there does not appear to be much
room for improvement in this direction.

We learn from a letter sent by Mr.
Colour Julius Rheinberg to Kaiurc (Novem-

Photography. l)er .'9), that the method of colour photo-
graphy with a lined screen and narrow
angle prism recently described by Professor Lippmann,
and referred to in this Journal for October last, was
the subject of a patent by F. \V. Lanchester in 1895,
was described by Julius Rheinberg in January, 1904,
and was patented in France early in 1906. Thus, it
appears that the process has been invented, according
to records, four times, and it is stated that others than
those named have been working on similar lines.

When formaline was first introduced,
The it w^i, thought that it might perhaps

Hardenins of displace common alum and chrome
Uelatine. alum as hardeners of gelatine. But
further experience with it has shown
that it also has its weak points. One essential differ-
ence between it and the alums is its volatility, and this
is not only annoying to the user, but remains a source
of uncertainty in its effects. It appears from some
recent work of Messrs. I.umiere and Seyewetz that
the treated gelatine is a more or less loo.se combination
of gelatine and formaldehyde, and that the formalde-
hyde is always ready to pass off and leave the gelatine
in its original soluble condition. It mav be separated

February, 1907.]

KNOWLEDGE & SCIENTIFIC NEWS.

33

slowlv, hut completely, hv hot water, bv cold dilute
hydrochloric acid, or by heating it to iio°C.

The recent action of two or three large
The Metric manufacturing firms has brought this
System of subject prominently to the front.
Weights and Photographers are peculiarly unfortu-
Measures. nate in having to use an ounce that is
divided into 437 1 grains, a figure that
no one can suggest is convenient for division, much
less sub-division. The figure is impossible, and other
figures, such as 440, 450, or 480, are substituted for it
when necessary, in spite of the error involved. The
metric system appears to be the one practical way out
of this and many other difficulties. But the present
metric system is founded upon arbitary stardards, and
so is fundamentally no better than the English systems.
It appears that when the metre was defined, those in-
terested set to work to make a model of it, and when
later the model was found to be a little wrong, the real
standard was neglected, and the incorrect model
adopted instead of it. .A vessel to hold a litre was
also made, and this was sub.sequently found not to hold
a cubic decimetre as it should, but instead of correcting
the error, that particular vessel was made the standard.
1 suggest that we want only a standard of length, and .
thatlhat should be defined, if possible, without reference
to any particular bar of metal. There must, of course,
Ix; secondary standards of length, weight, and capacity,
and from these other standards are needed to make the
measures from that are used in every-day work. But
I would suggest that all secondary and other standards
should l>e regarded merely as practical conveniences,
and if found to vary from the standard, should either be
corrected or so marked that their error may be allowed
for. Such errors as these would only exceptionally be
of importance, and would, of course, be known to all
concerned. The disadvantages of having standards of
kngth, weight, and capacity not simply related to each
other are so obvious that they hardly need pointing out.
We have, for example, already in the metric system two
standards of capacity, the litre and the cubic decimetre,
and we shall perhajjs get half-a-dozen others as time
goes on, unless we mend our ways. The trouble of
these many competing units is shown in the disregard
of their differences even in scientific work.

That portion of dust that cannot be
Laying the kept out of scientific instruments, such
Dust in as cameras, it is well to trap or catch.
Cameras. that its oresence may do as little harm
as possible. One method recommended
for this purpose is to smear the wood-work with a
trace of glycerine, so that whatever dust comes into
contact with it, sticks to it. Doubtless this is effective,
but the method does not commend itself to many
because of the trouble of cleaning the dust-laden sur-
face. Velvet catches dust and holds it lenatiously, it
is not messy, it does not need renewal, like glycerine,
and it is not very difficult to clean by brushing. If
black velvet is used, its light-absorbing power is an
additional advantage as a lining for optical instruments.
In all cases where dustless air is required in order to
prc\ent as far as possible the scattering of light, black
veh ;'t offers the double advantage of being the best
non-rjflccting surface as well as an eflicient dust-trap.

" The Photo-Miniature," to hand, almost
Received. a year after the date it bears, deals
with the " Hand Camera," and gives a
considerable amount of practical information.

MaLximvirrv of Mira^ Ceti.

By P. M. Ryves.

The variable star Mira (o Ceti) has lately passed an
unusually bright ma-\imum, having remained for three
weeks fully second magnitude, which is about the same
as at the time of its discovery by David Fabricus in 1595.
When observed on July 30 last, the brightness was
estimated as just under the ninth magnitude. It in-
creased, at first slowly then more rapidly, and reached
the seventh magnitude by October 17. About this
date a more rapid rise set in ; the star rushed up to the
second magnitude by December 2, a change corre-
sponding to an increase in light of a hundred times in
less than fifty days. The most rapid portion of this rise
was from the 6th to the 3rd mag. in 19 days (October
26-November 14).

A similar rapid rise to maximum occurred last winter
and is, in fact, a characteristic feature of the variation of
this and certain other of the variable stars of long period ;
but it is not always so well marked as in the present

»-Vi

|jtjLY"| A^-Qj\ep"[ OC^ j'nov*'| D^^C (T|*n'^| FtB | WAR

3

h
s

- 6

1

/

y
•>

»
10

M 1

RA

/

/

"s

S.

1

• sot

.,.,

I

-•

--..^

:

"'-.

:

l<105

■ <,o&

/

:

^

y

/

I6j^ to I* (.« W «Oo H *0 •• •• t<»r I,^ •— '

Light curve of Atira (o Ceti) 1906-7 compared with previous maximum.
Each curve is based upon about 40 observations.

case. This star may only reach the 5th mag. at maxi-
mum, and frequently does not exceed the 4th mag., but
when a bright maximum, like that of December last,
occurs, Mira surpasses in brightness any other variable
star of regular period.

On account of the general interest which attaches to
this variable and also the ease with which it may be
observed, it usually receives a good deal of attention
from amateurs when the epoch of maximum falls at a
season of the ye.tr when it can be conveniently observed.
Unfortunately, the position of Mira south of the ecliptic
and the period which brings the maxima about a month
earlier each year render it impossible to observe the
maxima well for several years together when they fall
in the spring arid summer months. A good series of
observations, extending well on either side of the epoch,
can only be obtained in the case of about half the
maxima, and those observers who do not work after mid-
night will he restricted to a still smaller proportion It
is, therefore, very desirable that a careful watch should
be kept upon this variable during the present and next
few years while the conditions are favourable. .\ special

34

KNOWLEDGE & SCIENTIFIC NEWS.

[I^ebruarY, 1907.

interest pertains to observations this season on account
of the brightness of the maximum. Such a bright
maximum is not hkely to occur uiulcr ciiually favourable
conditions more often than once in twenty years. It is
to be hoped, therefore, that those who have made careful
observations will publish the results, and thus contri-
bute towards a solution of that great problem, the cause
of variation of these mysterious bodies.

.\ provisional curve is given herewith, which shows
the general nature of light change during the past six
months, and, for comparison, an approximate curve for
the preceding season is superposed, the months being
the same for both. These curves are based upon 85
observations made by the writer in Spain. Those for
the present season are appended in tabular form. The
magnitude scale is that of tlie Harvard College Observa-
tory, and Harvard magnitudes have been adopted for
the comparison stars used. When possible, stars similar
in colour were used for comparison purposes in preference
to white or bluish stars. The change of colour is not
the least interesting feature of variable stars. Most of
them are red or orange, and some appear to become
redder as maximum is approached, but Mira, inten.sely
ruddy in its fainter stages, loses much of its colour when
the brightness increases. On September 15, the colour
w-as noted as a strong red, but about the time of maxi-
mum it had changed to a rather pale yellowish orange.

Observations of Mira, I906-7.

Julian Day

Julian Day

Date.

Mag.

2417000 +

Date.

Mag.

2417000 +

1906.

Nov

17 •

. 2-8o

532

July 30 .

. 9-07

.. 422

,,

19 .

2 68

534

Aug. I .

910

424

,,

20 .

2 55

535

., 17 ■

8 88

440

1 ,

22 .

238

537

.. 19 •

8-83

.. 442

,,

23 •

2 51

•• 53«

,, 21

8 92

■• 444

J,

26 .

215

541

.. 25 .

8-75

.. 448

,_

28 .

2 19

543

., 30 .

876

453

29 ■

2-09

544

Sept. 10 .

S-So

.. 464

30 ■

2 06

545

,. 14 ■

8-44

. . 4GH

Dec.

I

2-09

546

.> 15 •

836

469

,,

3 •

I 92

.. 548

.. 27 .

792

481

,,

9 •

1-85

554

Oct. 8 .

740

492

,,

II

1-85

.. 556

,. 15 •

715

499

, ,

15 .

1-96

.. 560

., 16 .

710

500

,,

16 .

I 88

.. 561

,, 21 .

6-67

505

,j

19 •

I 92

564

Nov. .3 .

4 23

.. 5i«

,,

24 .

2x0

.. 569

.. k. 7 ■

3 79

.. 522

1907.

..J-19 .

3-60

•• 524

Jan.

I

2-24

577

... 13 •

326

.. 528

,,

3 •

2-41

579

„ 14 •

3-20

.. 529

,,

5 ••

2-41

.. 581

., 15 ••

3 00

530

"

10 ..

2-50

.. 5S6

New Prism Binocular.

Messrs. .\. E. St.aley and Co., of 19, Thavics Inn, Holborn
Circus, E.C., have sent us for inspection a new prism
binocular, of the type now so popular, made by the firm of
E. Krauss and Co., Paris, for whom Messrs. Staley are the
British representatives. The binoculars magnify eight
times, and have an adjustable milled bar for focussing,
which moves both oculars, whilst one ocular has, in addi-
tion, a graduated adjustment to enable a difference in the
sight of the eyes to be separately rectified. The glasses are
also adjustable for width between the ej-es— an equally im-
portant matter. A minor improvement is a stud enabling
the binocular to stand upright on a table without damage.
The definition of these glasses is excellent, and they are
very' light, compact, and daintv, so that thev could be used
either out of doors, for which thev are, of course, primarily
intended, or in a theatre. The price, moreover, is onl'v

X.0 lOS.

The Bride-Stones — Cleveland Hills.

By E. J. SuMNEK, B.Sc.

TiiEkE arc sexeral groups of stones in various parts of
the Cle\ eland Hills which arc known as Hride-Stones,
of which the most im|)()sing are tho.se which look down
on the head of the \allev nrimed from thom — St;iindale
— about 8 miles north-east of l'ick<'ring.

The photogr;i|)li shows in the foreground one of the
c|uaiiilest of thes<' stones, known as the " .Salt-cellar,"
and to the loft of it, more distant, is visible a round
boss of the '' Chcesewring " type. The matcri;d is a

kind of gritstone, belonging to the oolitic series of
rocks, and consists of a number of layers of greatly
\arying hardness. It is generally supposed that the
sea is responsible for these curiously formed rocks, for
they resemble those upon which the sea is engaged
on the Vorkshire coast at the present day, though, of
course, the weathering action of wind, rain, and frost
w ill have largely altered them since the time when the
sea left them in their rough-hewn state.

The "'Salt-cellar" is some 20 feet high, about 10
jards round the waist or lowest part, and 20 or 30
3ards round nearer the top.

Some particulars have been published of the abortive experi-
ments in Transatlantic wireless telegraphy which were cut
sliort by the fall of the tower at Machrihanish. Messages
had been received and sent between Machrihanish on the
Mull of Cantyre, and Brant Rock, near Boston, U.S.A., but
it was found subsequently that not sufiicient allowance had
been made for the atmospheric absorption of the Hertzian
waves on all occasions, and in possibly unfavourable condi-
tions. At 1,500 miles 10 per cent, of the radiation got
through ; but when 3,000 miles was the distance it was
found that not i per cent, of the radiation could always be
depended upon. Indeed, during daj'light the absorption was
sometimes so great that not more than one-tenth of i per
cent, of the energy got through. As an illustration of the
complexities of atmospheric interference it is stated that,
with the same sending power, on some nights messages
were received 4S0 times stronger than was necessary for
audibility, and the messages could be read with the receiver
six inches away from the ear. On other nights with the
same sending power the messages were so faint that they
could not be read. A satisfactory factor of safety in trans-
mission had been achieved when the antennse blew down.

February, 1907.''

KNOWLEDGE & SCIENTIFIC NEWS.

35

A Fish Out of Water.

By Felix Oswald, D.Sc.

The well-worn saying, " to feci like a fish out of water,"
obviously embodies the general belief that fishes are
absolutely confined to the watery elei.ent. Nature,
however, never allows herself to be cramped by hard
and fast rules deduced from insufficient observation;
for, although a typical fish is eminently adapted for
swimming and breathing under water, yet tl.ere are
several striking deviations from this normal state of
things. For instance, the hopping gobies (in which
the fore-fin has developed a distinct elbow-joint) can
leave the sea and habitually skip along the shore in pur-
suit of insects and molluscs; the climbing perch can
exist for days out of water, and is even said to climb
palm trees, whilst the aerial flights of the flying fish are
known to all. These exceptions to the ordinary habits of
fishes are not merely of individual interest, but help us
materially to realise the somewhat analogous, but more
successful, struggle to invade the land which occurred
long ago, in pre-Carboniferous ages, on the part of far
less highly specialised fishes.

The radical organic changes resulting from this
invasion of a different element were mainly two-fold;
firstly,' in respiration — breathing by gills being ex-
changed for breathing by lungs, and secondly, in loco-
motion— fins being superseded by five-fingered, jointed
limbs.

Fig. I.— The Hopping: Ooby IPeriophthalmus),

In the modern invaders, such as the climbing perch
{Anabas scandcns) and the h(jpping gobies {Pcriophthal-
mus and Boleo phthalmus), gills still continue to be the
seat of respiration, but their structure is much modified.
In the case of the hopping gobies (Fig. i) the only
change in structure of the breathing-organs is an in-
crease in the size of the gill-cavity, which is thereby
able to contain air as well as water. The gills, how-
ever, are much reduced; and respiration seems also to
be carried on by the thin skin of the tail-fin. A more
advanced state of things occurs in the climbing perch,
in which there is an accessory organ in the gill-cavity,
consisting of labyrinthine folds of mucous membrane
(Fig. 2), so as to expose a larger respiratory surface to
the air — a direct result of terrestrial conditions. This
organ functions as a lung, by means of which the fish
is able to exist out of water for a long time, a fact
which Indian jugglers have made use of in adding this
fish to their stock-in-trade.

These labyrinthine organs may be profitably com-
pared with the somewhat analogous lung-like out-
growths in the upper half of the gill-cavity in land-
crabs (Gccarcinm and Birgiis lairo).

The lungs of land-vertebrates have, however, laeen
derived, not from the gills, but from the air-bladder of
fishes. This theorv is based essentiallv on the facts of
development, and is now generally admitted. Both
lungs and air-bladder arc formed bv an outgrowth from
the gullet, but the lungs arise ventrallv. while the air-

bladder in most fishes has a dorsal origin. This differ-
ence in position is not, however, so serious an objection
to the theory as it would appear at first sight, for in
Erythrinus it arises laterally, in Ceraiodus it becomes

Fig. 2.— The Climbing Perch iAna^ai ^cawUm,. The lower figure display*
the gill-chamber; a, the labyrinthine supra-branchial organ;
6 the gills.

I'ig. 3. — Diagrammatic transver.ie and longitudinal sections miter
Deam of air-bladder (il and adjacent digestive tract (■') of A,
Sturgeon and many Teleosts iPhyso.itomi' ; '>', »yi)iriiiii» ; C,
Ceratodm ; D, Lrpiilotirtn and ProlopUrui.

more ventral in position, and, finally, in Polypterus,
Calaiiioiclitliys, r.cpiJosirai, and Protopt<rus. it has
actually the same median ventral position as in all true
lungs (Fig. 3).

Now, when one organ is evolved from another, tliere

35

KNOWLEDGE & SCIENTIFIC NEWS.

IFliBRUARY, 1907.

is usually cithor a concomitant change of fundion, or
else a subordinate function may become exalted by tiie
altered circumstances into the first place.

The air-bladik'r in the m.ijority of cases has a jnuely
hydrostatic fum-lion, and swms t» prevent the fish
from too suddenly altering the depth at which the
conditions of life are most ad\ anlagcmis li> ll. l>nl il
the cli.inge in le\el be made grailuallx-, the necessary
compensation is oblaineil by the secretion or absorp-
tion of the gas in the air-bladder through the abundant
blood-capillaries (nV/i; iiiirahilKi), which usually line the
walls. For instance, Moreau has show 11 by his experi-
ments that if the air-bladder is emptied of the gas it
contains, the fish sinks to the bottom of the vessel in
which it is living, and cannot regain its ec|uilibrium
until it has secreted a fresh supply of gas. With regard
to this hvdrostatic function, it is interesting to note
that the air-bladder is not jjossessed by fiat-fishes,
living to the reason that they habitually rest on the
ground and lead a \ery sluggish existence. Hut il is
e(|ually absent in the large and ancient group ol
I';iasmobranchs (sharks, dog-lish, itc), unless llu'
obscure pharyngeal pouches should be regarded as
degenerate rudiments. Perhaps the notoriously pre-
datory habits of these fishes would ha\e rendered il
a disadvantage for them to have acquired an organ
w hich restricts a fish to a definite zone-level.

.Although the secretion of gas is the chief function
of the air-bladder, yet (as already indicated) some
absorption can. and does, take place in those fishes in
which the walls of the bladder are lined by blood-
capillaries {rctia nurabilui).* The two processes of
.secretion and absorption have only to take place alter-
nately and rhythmically in order to be equivalent to the
expiration and absorption of a true lung. Of course,
any actual breathing by means of the air-bladder can
only take place in those fishes in which the duct be-
tween the throat and the air-bladder still remains open
(the Pliysoslomi). Tliis connection with the exterior
l>8Comes of the greatest importance to the species
whenever the water it inhabits becomes muddy or in-
sufficiently aerated. Thus many of the meml>ers of the
great fresh-water family of cyprinoids (bleak, carp,
etc.) need to come periodically tO' the surface to sw-allow
air, ow ing to the frequent paucity of oxygen in the still
and stagnant waters which they inhabit. Many
siluroids, too, may be buried in mud for a long time
during the dry season, or can also travel on land from
one lake to another. Even our eel is known to traverse
considerable distances overland.

.\ still closer approximation to normal atmospheric
breathing is exhibited by a ganoid {Lepidosieus), and
by certain Brazilian fishes {Sudis gigas, Erylliriiiiis
/(Tuia/i/s, and brasilieiisis), which, according to Jobert,
speedily suffocate if the air-duct between the air-bladder
and the throat is ligatured, becau.se in these fishes gill-
breathing does not alone sufiice for the necessary
oxygenation of the blood.

But even in these cases the general course of the

• In the air bladder of Siluroids and of some other fishes [e.g..
Tench) the rctia mirahilut are absent ; in these cases a peculiar
chain of tiny bones (the Weberian ossicles) connects the air-
bladder with the inner ear. By means of these ossicles the fish is
mate aware of any increased pressure of air in the bladder caused
by sudden proximity to the surface of the water. Relief from this
pressure is obtained by the emission (doubtless by refle.x action) of
bubbles through the airduct and the mouth. The fish is thus
able to regulate its position to a plane of least muscular effort, in
which it becomes of the same weight, bulk for bulk, as the sur-
rounding water.

circulation has not been finidamentally .altered. To find
this state of things we must turn to the dipnoi, the
double-bicathcrs, or lung-fishes as they have been aptly
termed. In this ancient group of fishes, we ixn.- able
to trace tr.ansitional steps in the supplanting nt ^ill-
respiration by lung-breathing.

In Ccralodiis (the least specialised genus), the .-lii-
bladder is still imp;iired and dorsal in position, but a
slight median longitudinal depression ioresh.-idows the
p.airrd condition of the hings of hii^hcr animals. The
opening ol the air-duct, .•ilthough lati'ral, opens at the
glottis on the right side of the pharynx approximating
to the median ventral position of true lungs (i'ig. 3 6').
The latter condition is attained by the African I'ro-
toptcnix and the South American Lcpidosircit; and in
addition, the lung is paired (Fig. 3, V). The plan of
the circulation is modified, for the lung is now suijplied
with blood by a true pulmonary artery arising from the
point of union of the fourth efferent branchial artery
with the aortic root, while in Ctraindus it is still given
off from the former alone. 'l"he aiirated bloixl riturns
by a pulmonary vein to the heart through the sinus
venosus. In Prolnplcrus^ too, the conus arteriosus is
completely divided into two halves, so that an arterial
and a venous current pass out from the heart side by
side, while in Ccraiodtis this diyision is still incom])lete.
In all the members of the dipnoi, the lining memljrane
of the air-bladder is thrown into ridges and folds just
as in the hollow^ sack-like lungs of typical amphibians.

To this transitional group, therefore, we must turn
to find fossil remains intermediate between fishes and
amphibians. Their antiquity is great; the few existing
species are the widely distributed remnants of a group
which flourished in the later Paljeozoic ages. The
.\ustralian Barraniund:i {Ccraiodiis) is, indeed, a highly
remarkable instance of the persistence of a gencrali.sed
type, for the genus existed in the Trias of Europe, and
even in the Permian of North .America; the very fact
of its possessing low generalised characteristics has
enabled it to survive changes fatal to more highly
developed and specialised creatures.

TKe Pleiades.

For comparison with the plate in the January number,
we reproduce this month another photograph of the
Pleiades, taken by G. W. Ritchey with the2-feet reflector
at the Yerkes Observatory.

The plate had an exposure of three-and-a-half hours,
and shows the principal stars involved in a fine tracery
of nebulosity; the star Atlas," with its companion
Pleione, which brings up the rear of the Pleiades, is not
shown in this reproduction.

The small photograph, taken by W. Shackleton with
a 3i-inch lens, exposure 33 minutes, shows the group as
seen with a pair of opera-glasses, or a little more than
the naked-eye \iew.

* The names of the Pleiades stars, with diagram, are given in

" Knowledge " for January, 1889.

Supplement to " Knowledge & Scientific News," Frbriiaru. 1907-

<R.7.ri.,(uc.''.ii"»i Vol. II. "f III- I'lil'hcalii'ii- oi llir Y.rket Uhvrrolorii nt lltr Vnirmilii of Chic,„,i,..,

Nebvilosity in. the PleiaLdes.

February, 1907.]

KNOWLEDGE & SCIENTIFIC NEWS.

37

Basis of the Will.

1-'.\K g-i-L-ater dilliculties lia\o Ix-cn met with in the
attempt to fathom the mysteries of psychic or conscious
action, than with any other branch of Elementary
Bioioij-y. This seems to be due to the following-
causes : —

(1) Conscious action possesses no nervous grounds.
This gives support to the prevailing idea that, physio-
logically, its source is to be localised in such constitu-
ents as form the elements of physical or chemical action.

(2) Conscious action, though no doubt in possession
of a structural basis, affords but very complex clues
with regard to such a basis.

In the first place, conscious action is always synthetic
or complex. Conscious changes are produced without
anv consciousness of form. In respect to action, all
consciousness must be structural. For, how would it
be possible for changes of consciousness to occur, other-
wise than by means of sense of structure? But it does
not follow that, because all consciousness is structural,
structural action is conscious action. For, on the con-
trary, structural action is united action, a compound of
that which forms and that which is formed.

Physically, there are no changes of consciousness.
Energy has no nervous Substance of change, otherwise
such change would be found to have some nervous form
of transmutation, which is not the case. Changes of
consciousness, therefore, are not relati\e of structural
action. What is called the " Monism of energy," re-
presents a fundamental jjrinciple now generally recog-
nised throughout the province of physics and chemistry.

There must, therefore, be some principle to answer
for the action of conscious structure. The test of such
a principle will be in the structural difference of action.
Thus, the source of all changes of consciousness must
be a non-substantial of non-vital principle.

Now, there is strong scientific evidence which points
to man as being in possession of this principle. For
instance, it is through him that we arrive at last to a
structural transmutation of consciousness, to a psychic
form, which, in its relation to structure, has been pro-
ductive of pathological results.

In his Cumulative Evidences of Divine Revelation,
page 182, Mr. March Phillips gives the following signi-
ficant facts : —

"There is this peculiaritv in the condition of man,
as compared with the other mammalia, that his life is
shorter now than by analogy it ought to be. In other
animals the period of growth is about one-tenth to one-
fifteenth of the whole life. The lion, which is full-
grown at five, lives for seventv or eighty years. The
dog, full grow n at eighteen months, is as old at fifteen
as a man at eighty. Man, li\ ing as long as the lion, is
not full grown till twenty. The same proix>rtion would
give men from three hundred and twenty to four
hundred years. Thus, his physical life is not in this
respect the normal life; it is cut very short, and its
brevity points to some primeval failure of vigour — to
the presence of some non-natural, i.e., some diseased
condition, sapping his vitalit)."

Ag-ain, in his " Freedom of Science in the Modern
Slate," Professor Virchow says : —

If we gather together the w hf)le sum of the fossil
men hitherto known, and jjut them parallel with those
of the present time, we can decidedly pronounce there
are among living men a much greater number of in-
dividuals who show a relatively inferior typu than
among the fossils known up to this time."

Evolution, upon this evidence, can be said to have had
most astounding grounds for its moral tendency, from
such natural action as human physics here supplies.
However, it is not my intention to query any point of
physical ethics, but, rather, to bring into prominence
what are actually contradictory results produced under
similar action. Apart from reason, consciousness is
structurally unvarying in action — energy is monistic.
Combined with reason, there is conscious change of
action. Consequently, there must be some principle
through which man is structurally conscious. Physi-
cally, he is monistic; that is, an unvarying unity.
Rationally, he is a multiple, a being of character.

Where, then, is the source of this difference? As we
have seen, it is not a real or structural principle. It is
something abstract, something foreign to his normal
form of vitality. It must be some phantasy or myth,
otherwise, what is to answer for the prevalence of such
a degenerate and diseased condition of his life?

.Suppose we examine the conscious grounds of struc-
ture, and by this means locate the source of this evil
and non-natural element.

It is by means of the sensor nerves (properties of the
will) that consciousness structurally acts. Sensibility
is responsible for all structural actions. The motor
nerves, which determine structural actions, act without
any sense of structure, yet there must be a conscious
basis to structural action. Structural action is not
physical action; that is, action of growth. For, in
order that action may be consciouslv formed, the sense
of structure must exist as a foundation.

Consequently, structural action cannot result from
growth forms; but, on the contrary, these are them-
selves only possible through structural action.

.Structural action is relative of the sense of induction
— unity. Growth action is relative of the sense of struc-
ture. Consequently, the conscious grounds of struc-
ture is a unit of consciousness or vital cell. Upon this
unit of consciousness all reflex action depends, and it
must, therefore, be held to contain the elements of all
structural action.

Instinctive (adaptive) actions are never consciously
formed, but are relative of this unit of consciousness.

Conscious action is, structurally, unvarying, for all
action of sensibility is so formed, as sense of unvarying
sense of form, which is consciousness of conserved
energy. Consequently, the conscious ground of struc-
ture is un\arying action of consciousness, and non-
cellular; that is, action of infinite reflexion.

Upon what principle, therefore, must the ratit)nal or
conscious action of reflexion rest?

It certainly is not a structural principle, for this
reason, structural action is unvarying- will, whilst
rational actions are varying of adjustment; and, con-
sequently, such actions must emanate from an unvary-
ing and not a varying unit of conscious form.

How, therefore, can an unvarying consciousness,
prior to consciousness, and by which con.sciousness is
consciously formed, be consciouslv willed (united)?

Rationally, not otherwise than by free will, as an
infinite unit of conscious structure; consequentiv, onlv
as a subject of structure.

Thus, by analysis, no difference is to be found be-
tween instinct and reason, but, at the same time, it
exposes the source of the hitter's contradiction, which
is contained in the freedom of will.

In conclusion, it appears hardly necessarv to add
that, wherever man's freedom has run counter of his
normal or structural sense, there has ever been li>ss not
gain, pain not pleasure, disease not vigour, insanity not
control.

38

KNOWLEDGE & SCIENTIFIC NEWS.

[Feuruarv, 1907.

ASTRONOMICAL.

By Charles P. Butlek, A.R.C.Sc. (Lond.), F.R.P.S.

Solar Disturbances and the Corona.

An interesting paper is cniiinniiiicated to the Astiopliysical
Jounuil for Meceniber, 190(1, by F.itlier A. L. Cortie, in which
he discusses the relation of certain well-marked features of the
corona with areas of distnrbance on the solar surface as evi-
denced by various phenomena. That there exists a general
connection between the state of disturbance of the sun's
surface and immediate surroundings and the form of the
coronal appendages is sutTiciently well established. There is
a great similarity in type in the photographs of the solar
corona as photographed in the years 1.S70, 1882, 1893, and
ig05, all of them years of maximum sun-spot activity, marked
by many and great outbursts of spots and prominences. A
quite different type of corona corresponds to the years of
minimum solar activity, as illustrated by the photographs of
187S, iS8(), and igoi, while we have also examples of inter-
mediate or transition types in the eclipses of 1SS6 and 1896.
The uncertainty comes in when we attempt to decide whether
the spots or prominences are the more intimately connected
with the changes. Careful examination of the Stonyhurst
photographs (taken on a large scale) of the solar corona of
August 30, 1905, at \'inaro2, Spain, shows that the streamers
appear in general to mark the regions of the prominences
rather than of the sun spots. The longest streamers, consist-
ing of two long wings with an intermediate shorter streamer,
extend from latitude ~ 40" to — go" S., quite outside the spot
zone, while another streamer is located near the sun's north
pole. The fine group of prominences in the north-east quad-
rant was manifestly associated with three fine coronal
streamers. In the lower corona the complicated structure of
arches and vortex rings are seen to be attached to the pro-
minences.

Detailed measurements have been made on several of the
photographs in order to determine as accurately as possible
the exact area on the sun's surface from which the chief
streamers appear to be projected, and comparisons made with
other measurements made on the standard series of drawings
of the sun at Stonyhurst, thereby enabling the history of the
various spots visible before and after the eclipse to be studied.
The results apparently confirm the coincidences, and further
studies of the eclipse photographs of 1893 giving the same
conclusions, the author considers that not only in general is
a characteristic type of solar corona associated with sun-spot
and prominence activity, but that definite structures in the
corona are associated with definite areas of activity of sun
spots and faculje.

Prominences Observed During 190S.

In l-5ulletin Xo. \TI. of the Kodaikanal Observatory, the
Director gives the individual observations of prominences
observed during the latter half of igo5 and an abstract sum-
mary, showing the mean daily values and zone distribution for
the whole year.

Observations being made on 305 days, the total number of
prominences measured was 4757, giving a mean daily frequency
of 15-6.

A very noticeable feature is the slight variation noted in
the mean height for each month, the minimum of which is
28-4" and the maximum 357", giving a mean for the year
of 31-4".

The distribution with respect to the Solar equator is shown
to be very nearly balanced, being 7'8 for each 1 eniisphere.
The mean latitudes vary slightly in the two hemispheres, being
37'3° for the North and 3S-3° for the South.

A detailed analysis of the numbers of prominences observed
fcr each quarter and half-year in zones of 10' width from

pole to pole is also included, enabling the prominence record
to be compared in dutail with other solar phenomena.

Observations of Phcebe.

Professor E. C. Pickering gives a list ol nine additional
photographs of Saturn, showing images of the ninth satellite,
Phn.bc, which have been obt.iined with the 24inch Bruce
telescope at Arequipa during August and September, 1906.
The exposures for these plates varied from lo^ to 120 minutes.
Reductions of the photographsshowiug the position angles, and
distances are given, these varying from 251° and 12'4' on
.Xugnst II to joo" and 2'o' on September 17. (Harvard
College Observatory ("irciil.ir No. 119.)

Nova Veiorum.

During the examination of photographs taken at the Harvard
College Observatory with the i-inch Cooke lens, a new object
was found in the Constellation Vela, with position as follows : —
K.A. = 10 h. 58 m. 20 s. ; Decl. = — 53" srg" (1900). It
follows a fifteenth magnitude star by about 2 s., and is 15'
south of it. Owing to the small scale of these plates, measure-
ments of position and brightness were ditTicult. The object
does not appear on any plate taken before December 5, 1905,
hut is seen on fourteen plates since that date ; and on July 2,
1906, it had again fallen below magnitude ii'2. The greatest
brilliancy occurred about Jatui.ary 1, 1900, when the magnitude
was 9'72; but during the period covered by the ol)ser\ations
the Nova exhibited considerable lluctuations in light, and it
seems not impossible that it may again become sufficiently
bright for its spectrum to be obtained, but even without such
proof there is apparently little doubt that the object observed
is actually a Nova. (Harvard College Observatory Circular
No. 121.)

Companion to the Observatory for 1907.

Except for a fesv minor alterations the present issue of this
most useful compendium resembles closely those of previous
years.

The section dealing with variable stars has been slightly
re-arranged, this b?ing necessitated by the continued increase
in the number of known variables, which now total 574 in
M. Loewy's list. The complete list of stars with their places
is not now given, and the dates of maxima and mimima of
long-period variables are shown in a somewhat different form.
These Ephemerides are j^iven in Gi-cnni'icli incait astronomical
time, counting from noon to noon, and not from midnight to
midnight, as in former years. The range of magnitude is added
at the top of each column.

The occultations of stars by the moon are alsoincreased^in
number by the inclusion of stars fainter than 6-8. No diagram
of the orbit of Saturn's satellites is given, as their plane passes
through the Earth during 1907.

New Variable Stars.

The study of the distribution of variable stars by super-
posing a negative on a positive of different date has been
continued by Miss Leavitt at Harvard College Observatory
with very interesting results. From photographs taken with
the 24-inch Bruce telescope thirty-one new variables have
been discovered, including one in the region of the Pleiades,
two near the nebula of Orion, and twenty-eight in the region
of the " Southern Cross " and " Coalsack." From the
absence of variables in the first group it would appear that
the conditions in the vicinity of the Pleiades favour unusual
constancy in light, as no other stars were ever suspected of
variability, though there are many suspected variables in the
other regions examined in this way.

On photographs taken with the i-inch Cooke lens, covering
a region 30° square, and showing stars down to the eleventh
magnitude, thirty-six new variables have been discovered, and
in addition most of those already known have been re-detected.
Six of them belong to the Algol type, and a full discussion of
their periods wilFbe given later in the annals. (Harvard
College Observatory Circulars Nos. 120, 122.)

Total Eclipse of the Sun, January 14, 1907,

Only meagre reports are to hand as to the total solar eclipse
which took place on Monday, January 14. In a message from
Renter's Agency at Samarkand, it was stated that the eclipse
of the sun was observed from a point on the railway between
Kuropatkino and Mijulnsk^ja. The first stage of the eclipse

February, 1907 ]

KNOWLEDGE & SCIENTIFIC NEWS.

39

was noted a few minutes after nine o'clock ; totality occurred
at seven minutes to ten, and lasted for two minutes, the sun
being clear again shortly after ten. As it is also reported
that snow was falling throughout totality, it seems probable
that most of the observations depending on photographic de-
lineation will have been at a disadvantage. Other observers
were to be stationed at Tashkend, but no report is as yet
available from there.

Artificial Reppoduction of Lunar Craters.

M. Gaston Hauet describes an interesting method of pro-
ducing artificially variously figured structures which are
strongly suggestive of lunar formations. Placing a quantity
of wax in a copper vessel heated by a gas flame, as soon as the
mass commences to soften a metallic rod moistened with water
is plunged into the mass and quickly withdrawn, taking care
to close the orifice caused by the insertion of the rod.

.■\fter a few seconds the gas is turned on stronger, so as to
heat the lower part of the wax, and a swelling is seen forming
on the surface of the wax. This increases and at a certain
stage in its development bursts about its upper part. A jet of
steam escapes, and the swelling subsides in the form of a
circular ridge with vertical walls. By this the action of the
steam inside the mass has been relieved for a time, but after
a short interval a similar series of phenomena will be repeated ;
if the new swelling happens to come up inside the former
there will be formed a central cone very strikingly similar to
those so characteristic of true lunar formations.

BOTANICAL.

By G. Massee.

Delayed Germination.

It is a well-known fact that in the case of many plants the
seeds produced by one crop do not all germinate promptly
when placed under favourable conditions for doing so. In-
stead of this the seeds germinate at irregular intervals, ex-
tending through a period of weeks, months, or even years.
In other plants the seeds will not germinate under what
may be termed normal conditions within a year of their
production, and in such instances certain of the seeds show
a further marked dela)' in germination. Numerous experi-
ments have been made, and suggestions offered as an
explanation of this erratic behaviour of seeds. Arthur has
described a ven,- interesting case of delayed germination in
the seeds of the cockle bur {Xanthivm canadense). The two
seeds present in the bur are not exactly counterparts of each
other, and are produced at different levels. All the low'er-
most seeds germinated the first year after ripening, w-hereas
those seeds produced higher up in the bur did not germinate
until the second year after ripening, and a few were delayed
until the third or fourth year. The author considered that
the seed coats did not differ in the two seeds, and suggested
that enzymes are produced readily in the lower seeds, and
that, therefore, they had food available for immediate
germination, w'hereas the upper seeds are only able to form
digestive ferments after a considerable period of rest. To
determine this question more exactly, Dr. Crocker, of the
Hull Botanical Laboratory, U.S..\., carried out a series of
experiments with the seeds of various plants, including five
kinds of Xanthium, and the dimorphic seeds of Axyris
amaranihoides. His conclusions are as follow : — Delayed
germination is, as a rule, due to the seed coats rather than
to the embryos ; in other words, it is more dependent on
mechanical than physiological causes. In soine instances
retardation is due to the seed coat excluding the required
amount of oxygen. This is the case in Xanihium, but the
exclusion of oxygen is much more marked in the case of the
upper seeds than in that of the lower ones, hence the differ-
ence in time required for germination. .\ high temperature
brings about the germination of the upper seeds of
Xaiifhium at once by increasing the rate of diffusion of
oxygen. In Axyris amaraiifhnides, Aliutilnn, Avicenna, and
many other seeds, retardation is due to the exclusion of
w'ater by the seed coats. In 7ris seeds the failure to
germinate quickly is due to the endosperm and cap arresting
the .ibsorption of water, and it is onlv when a certain

amount of decay in these structures has taken place that
germination is possible.

Seed coats which exclude water are better adapted for
retarding germination thdn when oxygen alone is excluded,
because of the much greater reduction of transpiration in
the first case.

Hawthorn seeds would not germinate immediately after
ripening, even when the seed coats were removed, and after
subjection to high temperatures and high oxygen pressures.
In this case it was obvious that the changes necessary for
germination were located in the embryo ; nevertheless, it is
also, to some extent, due to disintegration of the seed coats,
because germination in the end is only effected after long
exposure to conditions favourable to germination, and not
when the seeds are kept dry.

Treatment of Deteriorated Tea.

Dr. H. Mann, in Bull. No. 4, of the Indian Tea .\s-
soeiation, deals with the gradual deterioration of the tea
plant a few years after planting, the bushes rapidly losing
their early vigour, and after a period varjing from 10 to
20 years they are past their prime. The old method of re-
storing such waning bushes by hard pruning is not always
successful, because in some instances hundreds, or even
thousands, of acres have been collar pruned w hen the bushes
are suffering from causes for which collar pruning is no
remed}'. The signs of deterioration are a change in colour
of the foliage, which assumes an unhealthy, yellowish ap-
pearance ; at a later stage the young shoots soon cease to
grow, and do not produce leaves.

.\mong causes of deterioration the principal are, ex-
haustion of available plant food in the soil, exhaustion of
the bush, and incorrect pruning. A detailed account of the
methods by which the primary cause of failure may be de-
tected is given ; also the practical methods, including drain-
age, manuring, piuning, &c., which seem best adapted for
bringing back to a profitable condition much of the tea in
India which has now declined from its former value.

CHEMICAL.

By C. AiNswoRTH Mitchell, B.A. (^O.kod.), F.I.C.

Action of Plants on Photogrraphic Plates in
the Dark.

Dr. W. J. Russell has extended his experiments on the
action of wood upon photographic plates in the dark (see
" Knowledge & Scientific News " Vol. II., 119, 235), and
has tried the effect of various seeds, leaves, and roots. He
finds that the reducing power is very widely distributed, and
that many parts of the plant produce as marked an effect as
the wood itself. In the embryo state seeds appear to be
inert, but as soon as growth begins the reducing property
manifests itself, and continues until the death of the plant.
.\\\ leaves were found to have this property, even those lying
dead beneath the trees still possessing it, though to a reduced
extent. The best method of preparing leaves is to press
them between blotting paper under a pressure of one to
five tons to the inch ; the liquid absorbed by the paper is
also able to act upon the plate. Dr. Russell's hypothesis is
that the active agent in the reduction is hydrogen peroxide
— at all events, the activity of the plant is comparable with
that of hydrogen peroxide. Thus the seed leaf of the runner
bean has practically the sanie action on a plate at a distance
of an eighth of an inch as a solution of one part of hydrogen
peroxide in 100,000 acting at the same distance for the same
length of time (24 hoursT. The kernels of nuts are inactive
at first, but after exposure to the air produce a verj- dark
picture. Castor oil seeds are the least active in this re-
spect, and the liquid expressed from them mav be exposed
to the air for a month or mure without becoming active. It
is not unlikely that some connection m.ay be traced between
the drying capacity of the oil in the seed and its reducing
power. The outside shells of seeds are quite inactive. In
the cocoanut shell, for instance, the light-coloured portion
has no effect upon a plate, whereas the darker parts are
very active. In many cases the roots of plants have a verj-
strong reducing action, the root of the Scotch fir, for ex-
ample, giving a picture similar to that produced by the
wood .

40

KNOWLEDGE c^ SCIENTIFIC NEWS.

[February, 1907.

Natural and Artificial Mineral Waters.

It miylit 1h' iIuiu.i;1u llial liv ili>siih iiij;" (lii' iii;lil sail-- in
the right iiropoitioji in distilled water any natural niiiural
water could be exactly imitated; and, in fact, special salts
are sold to be used in the pre])aration of water from various
well-known mineral sprinj^s. It has been shown, however,
by M. Neijreano that the natural waters dilTer from the
artilici.il imitations in ;in important physical chaiacterislic,
so jiiuch so that this can be used as ;i test for distinj^uishing
betwetn the two. 'J'he resistance offered to the passat^f of
an electrical current appears to be practically a constant in
tlie case of a natural mineral water, and will dilTereiiliate it
from other natural waters. For instance, X'ichy water was
found to have a resistance (in ohnis^ — c.c. at 180 C.) of i^o;
\'illel water, 500; and livian water i,2So. Artificial watirs
with pr.iclically the same chemical composition y;ave very
dilferent results, however, such as, for example, 112 in lln'
case of artificial \'ichy water, and 1,120 in that of artilici.il
Kvian water.
A Test for the Blood of Different Animals.

.\ simple modilicatioii of the serum mellu)d ol tlilh reiiliatini;
the blood of dilferent .•uiimals (sei> " Knowt.i;i>c.i-; X: .S( ii-:.\-
ril-ic NliW.s " \'ol. II., .S(), !()()) has been deviseil by llerr
PiorkowsUi, and h.'is the s^reat adv;int;ii;c of not requirini;'
the use of ;i livini^- animal. .V small quaiitity oi serum from
a {.fiven anim.il, say a horse, is i)l.iced in a very small test
tube into which is then introduced one drop of the fresh
blood under examination, diluted 10 to 15 times, or of ;i
solution of the dried blood in a solution of salt. The tube
is allowed to stand for about 45 minutes, after which its
contents are examined. If the blood introduced w-as from
an animal of the same species as su[)plied the serum (a horse
in our hy|)olhetical case) a faint red precipitate of coaj^u-
lated blood will be seen, while the liquid above will have
remained clear. On the other hand, the blood of an animal
of any other species will have disst)l\-ed in the foreign
serum, colouring it red. The reaction is made more con-
clusive by shaking the tube at intervals of 30 minutes after
the first coagul;ition, a fresh precipitate being formed each
time. The method is stated to have given very satisfactorv
results in the ex.imination of old stains of human blood,
the test tubes being ])reviously charged with fresh human
serum.

The Gases Enclosed in Coal.
Analyses have been made by Mr. V. Trobridge of the
gases enclosed in coal from Birtlcy, in Durham, in the dust
left on screening the coal, and in that deposited on the
timbers in the mine. The air was first removed by means
of a mercury pump from the flask in which the coal was
placed, and the gases subsequently given off by the coal in
the exhausted flask collected over mercurv measured and
examined. Finally the flask was heated by boiling water
to expel the residual gases. It was found that the samples
of bright coal yielded the largest amount, and that these
gases contained the largest proportion of combustible con-
stituents, the latter consisting almost entirely of marsh gas.
The gases occluded by the surface dust and the dust on the
timbers amounted to about one-twelfth of the quantity in
the bright coal, and contained other hydrocarbons of the
same series as marsh gas. .An interesting point was that
the proportion of oxygen in the portion of air last removed
from the flask was greater than in air. Further experi-
ments showed that freshly-hewn coal exposed to the air
gradually parted with its enclosed gases, and at the same
time absorbed nitrogen and oxygen from the atmosphere,
the latter in the greater proportion. Nitrogen formed a
considerable part of the gases obtained from the different
samples, and experiments are being made to determine
whether this nitrogen contained argon and other inert gases
that accompany nitrogen in the air.

GEOLOGICAL.

By Edward A. Martin, F.G.S.

A Small Triassic Dinosaur.

Dr. a. Smith-Woodward, the Keepsr of the Geological
Departmeat of the British Mussum, has described in detail

to an enchanted audience, at the meetinj,' of the Geological
Society, two small skeletons of a new reptile from the
Triassic sandstone of Lossiemouth. The specimens were
discovered by Mr. \V. Taylor, of IClgin, and appear to be the
same as two imperfect skeletons which are already in the
British Museum. The head and trunk measure only 4 inches
in length, but there is a very long and slender tail, 'i'he head
is relatively large, and resembles that of Oniilhostichus in
many respects; but the fossils do not exhibit any teeth.
There are about twenty-one presacral vertebne, of which
nine are cervical. Thi^re are distinct traces of a plastron
of delicate abdominal ribs. The limb bones exhibit ;i large
internal cavity. The foreliiubs are very small, with a
liuiucrus as long as the radius and ulna. The hind-limbs
are relatively large, and the ilium is extended aiitero-postcriorly
for the length of four vertebrie. The femur is almost as long
••is the tibia and fibula; while the metatarsus is especially
remarkable, being half as long as the tibia and consisting of
four metatarsals of nearly equal length firmly fused together.
The toes are long and slender, with sharply-pointed claws.
The most remarkable feature is undoubtedly the elongated
metatarsus, and the fusing together of the bones suggest
that the creature was in the habit of squatting thereon, and
that their united breadth would prevent it from sinking
into its boggy haunts or into the soft sands of a shore. At
the same time the distinct internal cast which appears of a
limb bone suggests adaptation for flight, and the whole struc-
ture would on account of its lightness seem suited for it.
The smallness of the fore-limbs seem to show that these were
seldom put to the ground, but this of course agrees with similar
limbs in other dinosaurs. The creature has been classed
with the dinosaurian reptiles on perhaps somewhat negative
testimony, and the suggestion that it might have possessed
some means of avian flight, although there were no traces of
wing-feathers or membrane, will no doubt not be lost sight of,
should any further specimens be discovered.

A Neolithic Burial at Whyteleafe.

A reprint has reached me oi a paper read by Mr. A. J. Hogg
before the Croydon Natural History Society, " On Human
and other bones found at Whyteleafe in Surrey." The site
is in the well-known Caterham Valley, along which the inter-
mittent Bourne flows from time to time. The bones were
found in October, iSg6. They lay on the undisturbed
surface of the chalk, but at the base of S ft. 3 in. of super-
incumbent dark brown or red loam, and grey marly chalk
rubble. The burial was made in the usual neolithic crouching
position, and the body seems to have been let down a shaft
into a dome-shaped excavation about 4 ft. 6 in. in height.

The bee-hive or dome-shaped form of the hut, or the
sepulchral chamber, appears to represent everywhere the
ideal architecture of the Neolithic period, and was well ex-
emplified by the underground chambers discovered at Waddon
in igo2, which were ably described by Mr. George Clinch,
F.G.S., before they again disappeared from view.

The human remains recovered at Whyteleafe consist of : —

1. Portions of the occipital and parietal bones of the skull.

2. The right ramus of the lower jaw, with eight teeth.

3. The shaft of the right femur, or thigh-bone.

4. The shaft of the right tibia, or shin-bone.

The bones of the skull which are preserved are thick — in
the thickest part (the upper curved line of the occipital) five-
eighths of an inch. The remarkable rugosity of the occipital
appears to indicate the attachment of powerful muscles.

The animal remains which were exhumed from the brown
loam included those of the cijuiis (small horse), boslongifrous,
ca-vus, and ovis. Mr. A. J. Hogg concludes his paper by
remarking that the age of the Whyteleafe interment may be
taken approximately as that of the close of the Stone Age, as
determined by observations made in Switzerland namely,
about seven thousand years ago.

A Wealden Crocodile.

Although the species of fossil crocodile, GontopJwhs crassi-
liius, was founded many years ago, it has only been quite
recently that the skull was discovered for the first time.
This fortune fell to Mr. R. W. Hooley, F.G.Z., who by great
carefulness and patience collected the remains of this fossil
crocodile from a disintegrating mass of Wealden Shales from
Atherfield in the Isle of Wight. This mass, comprising many

February, 1907.]

KNOWLEDGE & SCIENTIFIC NEWS.

41

thousand tons, subsided, pushing its foot across the beach
until below low-water line. As the sea washed away the base,
the mass continued to sink, and fresh horizons were denuded.
In 1905 a series of heavy " ground-seas" cast up blocks of
limestone and ironstone, containing crocodile bones, which
were discovered on the sand between high and low-water
marks. The skull came ashore in six pieces, whilst fragments
of bones and scutes were constantly picked up, and Mr.
Hooley spent many days collecting the remains as the sea
sorted them out and cast them up on shore. The specimens
were derived from a horizon So to 90 feet below the top of the
Wealden Shales.

The paper describing the discovery was read before the
Geological Society of London, and Dr. A. Smith-Woodward
in commenting favourably on it remarked that although
the remains of Goniopliolis cicissideits were among the com-
monest Wealden fossils, the precise characters of the species
had remained unknown, until the discovery which the author
had described. The new observations were of all the greater
value because the Goniopholid:E represented an entirely new
departure in the evolution of the Crocodilia at the end of the
Jurassic Period, and biologists needed an exact knowledge of
the skeleton of these reptiles before they could discuss the
meaning of the development in question. The late Sir Richard
Owen thought that the first appearance of alligator-shaped
crocodiles such as Goniopholis was correlated with the in-
coming of warm-blooded quadrupeds and birds.

ORNITHOLOGICAL.

By W. P. PvcRAFT, A.L.S., F.Z.S., M.B.O.U., &c.

The " Dpumming " of the Snipe.

At the last meeting of the Zoological Society, Mr. Philip H.
Bahr gave a most interesting demonstration, illustrating the
results of his inquiry into the vexed question as to the mechan-
ism which causes the remarkable sounds made by the Common
Snipe during the breeding season — sounds which are described
by some as "drumming," by others as " bleating."

While the older naturalists believed these sounds to be
vocal, later observers held that they were produced by the
wings, and others by the tail. The latter view has been widely
accepted for many years, and the experiments which Mr. Bahr
made to test the truth of this should remove the last doubts
on the subject which some yet maintain.

He showed conclusively that the principal agents in this
matter are the outer tail feathers, which are peculiar, not only
in having an unusually thickened and peculiarly curved shaft,
but also in the great width of the inner vane. This is further-
more strengthened by means of very large and numerous
" booklets " — microscopic structures which hold the backs of
the feather in position by reason of the grip they take of certain
specially modified barbules.

He extended his examination so as to include every known
species of Snipe, and found that in many species the sounds
produced are extremely high-pitched, by reason of the narrow-
ness of the feathers concerned. This decrease in the width of
the vane reaches its maximum in the Pin-Tailed Snipe
{Galliiiogo stcnuni), which has furllier increased the number
of the tail feathers to 26 pairs ! But here the development
has been carried to such an extreme that all sound-producing
power has become lost.

House Martin in December.

Mr. C. H. Howard, in the Field, December 22, records the
fact that he saw a House Martin hawking for flies on the
Parade at ICaslbourne on December 9.

Baiiion's Crake in Kent.

According to the I'icU, December 22, a Baillon's Crake
(Pur::ana hailloni) was shot at Lydd, Kent, on November 24,
by Captain R, .-Vlexander, It proved to be a female, and was
flushed from a rush-covered pool near the sea.
Sea Eagle in Surrey.

An immature male Sea l^agle (llaliintus (ilhlciUa) was shot
at Chevcrills, Surrey, by a gamekeeper on November 12, and
was duly recorded, as usual, in the daily Press as a Golden
Eagle. This makes the fourth authenticated record of this
species for Surrey.

Honey Buzzard in Wales.

Mr. H. E. Forrest, in the Zoologist for January, gives a short
account of a Honey Buzzard {Pcniis nt>ivorotis} which was
•' inadvertently " shot by a keeper at Kerry, near Montgomery,
on June 21, igo6. On dissection it proved to be a female.
This appears to be the first authenticated record of the
occurrence of this species in the county ; while in the whole
of North Wales it does not appear to have occurred more
than eight times.

Mediterranean Black-Headed Gull.

Mr. Forrest, in the same issue of the Zoulogist, brings to
light two hitherto unrecorded instances of the occurrence of
the Mediterranean Black-Headed Gull {Lams melatiocephahis)
in this, countr)'. These birds are now in the collection of
Mr. Beville Staines, of Peplow Hall, Salop. They are described
in the M.S. Catalogue of Harry Shaw as follows : "The pair
of birds in this collection were killed near Falmouth in
March, 1S51 ; the only specimens of their kind recorded as
obtained in the country." It is certainly remarkable that such
rarities should so long have remained in obscurity.

PHYSICAL.

By Alfred W. Porter, B.Sc.

Poulsen-Pederson System of Wireless
Telegraphy.

The great desideratum in wirek^s telegraphy is a system
of \v;ivfs which is practically continuous. In Hertzian tele-
ijraphy each spark in the sending apparatus lasts for only a
small fraction of the time, and the corresponding waves are
equally intermittent. A few waves pass, each one less in-
tense than the one before it, there is then a long pause
before a new series is excited, and this, in turn, rapidly de-
creases in intensity. The consequence is that the total
effect in any moderate time is very small, and the greatest
distance for easy signalling is correspondingly short. It is
now claimed by Poulsen that this desideratum is supplied by
making use of the singing electric arc.

Duddell some years ago showed that if a shunt consisting
of a suitable inductance and cnp.acity be applied to the
terminals of a solid carbon continuous current arc lamp the
arc will, under definite conditions, begin and continue to
sing. The singing is the audible sign of an oscillatory
current in the shunt circuit. By adjusting the inductance
and capacity, Duddell was able to obtain very high fre-
quencies of alternation amounting to 40,000 periods per
second. But with a single arc he was un.ible to satisfy the
necessary conditions with a larger current than five amperes.
This frequency and current are small compared with what
is required for distant wireless telegraphy. Poulsen now
claims that by putting the arc in hydrogen or a hydrogen-
containing atmosphere a much higher frequency is obtain-
.ible ; for example, as high as one million per second; and,
moreover, that succeeding oscill.itions are all of equal in-
tensity. Improv(Mnent is also elTected by applying a trans-
verse magnetic lield to the arc, and also by keeping the
anode cool. The l.itter is effected by repl.icing the anode
carbon by copper and cooling it with a stream of water.
The externals at the sending station do not present much
peculiarity. There is the usual antenna attacheil to the
oscill.iting circuit. In a large station erected in Denmark
the potential difl'erence between antenna and earth amounted
to .ibout 2,000 volts, ant! the rate of radiation of energy from
the antenna was .about 100 watts, or about one-seventh of
that sujjplied to the arc. With this good signals were re-
ceived 300 kilometres .iw.iy. Later still greater radi.ilion
has been obtained, sulVicient to carry some thousands of
metres. .\t the receiving end a special receiver is useil
which was devised by Pederson.

The radiation is received by an antenna whoso circuit is
accur.Uelv tuned to the frequency of the w.ives received, so
that the principle of resonance is utilised to the fullest ex-
tent. To prevent the damping of tliise oscillations the
indicating appar.itus is only intermittently connected with
the receiver. This intermittent connection is made bv a
small, electromagnelically driven interrupter called a
Tikker. The indicator itself may be an electrolyte cell, a

42

KNOWLEDGE & SCIENTIFIC NEWS.

[Febri'arv, 1907.

thcrmo-clcmont, or a bolomctric arrnnRomont in combinn-
tion with a trlrphonc. The intormillomc indoclucod by lln-
til^lvcr is SI) threat that in the tclcphono a bif^h note is heard.
It is clainiftl that very fine tiiniiijjf can be cniploycd, witli llic
resultinfj ndvantajj^'e that neinhboiirinfi stations may br
closer loiifetlier without distiirbinjj^ one anollier.

Time alone will show to what extent the claims of this
new system will be substantiated. In a leadinjj article in
the Wcciricinn (Oecember 21, iqob), which, in the main, is
eulogistic, there is a considerable amount of cautious
criticism of the claims and the methods of achieving them ;
and the opinion is expressed " that there need be no haste
in scr.ippintj plants at present in operation, and that il m;iy
vet be many y<>ars before the musical arc can sinjj the diri^e
of the spark."

Mr. nuddell, in the last of his Christmas lectures lo
juveniles ;it the Roy.il Institution, showed such a sendini;'
anil receiviuij apparatus at work, and illustrated experi-
menl.illy the sh.irpness of tunintj which is nocessarv for
producing.;' the best effect.

Disintegration Products of Actiniun^.

The disinletjration series of acliniuni has been thoroui;blv
invesliijated by Dr. O. Ilahn, and the folUnvinfj six statues
have been determined :—

PrODI'CT.

—

Time to be Half
Transformed.

Radiation.

Actinium

1

■>

Rayluss.

Rad'i actinium

Abe

ut

19-5 days.

a rays.

Actinium X . .

IO-2

0 rays.

1
Emanation . .
1

39 sec.

a rays.

1

Actinium A.

1

<u

i

36 min.

Rayless.

Actinium B.

<

0.

a;
t3

2 ,,

a ^ ar.d 7 rays.

The Monochroma.tism of the Red Cadmium
Spectrum Line.

While .Micbelson's echelon grating' and also Fabrv and
Perot's interferometer indicated that the cadmium red line
was single, doubt had been thrown upon this result by the
fact that with Lummer and GchrcUe's apparatus it ap-
peared accompanied by several components. The doubt was
as to whether these components were real — in which case
the red light of cadmium would be a much more imperfect
source of pure light than had previously been hoped ; or
whether they were only ghosts or accidental appearances
arising from imperfectness in the apparatus employed.
This apparatus consists simply in a long parallel plate of
glass. A parallel beain of light is admitted in a very
oblique direction, and is internally reflected a large number
of times, a portion of it escaping at each reflection so as to
form an aggregate of parallel beams, between each of which
a certain phase-difference exists due to difference of re-
tardation in passing through the plate. A similar result
to this is produced in other interference apparatus, and
Lummer claimed great efiiciency for his particular arrange-
ment. Gehrcke and von Baeyer have now shown how to
distinguish between a ghost and a true component by the
use of an additional plate. The result of their test "is to
show that the apparent structure of the red line is wholly
due to ghosts, and therefore all the different interference
devices which are employed to test structure are now in
complete agreement. Similarly with regard to the green
mercury line. Lummer had obtained a much more com-
plicated structure than other observers. Here again, when
the new test is applied, the additional complication is .shown
to be spurious. It is very satisfactory to find the various
devices all leading to concordant results. In order to
indicate the superiority of interference apparatus over diffrac-
tive gratings it may be pointed out that no grating has
ever been ruled which is able to reveal the structure which,
with interference apparatus, is here being studied in detail.

ZOOLOGICAL.

By K. Lydekker.
is there a British Freshwater iVIcdusaP

.\iu)i|- twenty jcars .ago it was iliscovered that certain
slieams in rhiladelphi.-i were inhabited by a small polyp,
which lives attached to stones at the bottom of Ihe water.
Twelve years later it w;is observed Ihat this Micmlttjilra,
,-is il is called, reproduces itself by giving off free-swimming
jell\-lislKs or medusas. All this, it may be said, has
noliiing to do with a British jelly-lish. 'I'rue, but in certain
hot-house tanks there were at one time noticed small, fixed
jjolyps, then regarded as the sedentary stage of the free
jelly-fish previously obserNcd in llie Vidorin rcgia tanks in
the Regent's Park; and ihe suggestion now is, thai these
fixed polyps may possibly prove lo be indigenous British
representatives of the .American Micraliydra. Whether it is
worlh the while of amateur naturalists to commence
bunling for this problemalical creature must be left to the
(Ici'isicm of members of lh.-il liody.

British Bears.

Professor .S. II. R(\ Molds, of Bristol, has done much to
iricrease our knowledge of the bears which inhaliiled Ihe
British Isles during the Pleistocene and Prehistoric epochs,
in a memoir issued among the Palaontograijhical .Societv's
monogiaphs for 1906. The author fmds that all these bears
are closely related, but considers it advisable, on Ihe whole,
to retain the great cave-bear, Ursiis spctiiiis, as a distinct
species. All the rest he groups under the title of I'rxiix
(irrfiis, as typified by the brown bear of Scandinavia. Of
s()ecial imporlance is the opinion that the ri'ference of cer-
tain British (including Irish) bears to the .American grizzlv
{!'. a. horrihiU.*) cannot be substantiated. This is quite
in accordance with what might be expected from other con-
siderations ; for the grizzly bear (as now restricted) does
not occur in the higher latitudes of North America, where
its place is taken by races more nearly akin to the European
brown bear and its Asiatic representatives. If, then, any
of Ihe British bears exhibited marked resemblances to the
grizzly, it is obvious that such resemblances could only
indicate the existence in the British Isles of a race represent-
ing the American animal, and not that race itself.

The Attis Spider.

The Rev. O. P. Cambridge ])oints out in the Naturcilist
that the power of changing the colour of their eyes
possessed by certain spiders from Java (to which reference
was made in our last issue) is not a new phenomenon. The
same thing has been previously observed in other spiders
of the Attis family.

Papers Read.

.At the meeting of the Zoological Society on December
II, igo6, Messrs. J. Rennie and H. Wiseman contributed
a paper on the " Ascidians of the Cape Verde Islands," in
the course of which three species were described as new.
The arterial system of certain frogs and toads formed the
subject of a paper by Mr. L. K. Crawshay ; while fiftv-three
new African weevils were named and described bv Mr. G.
A. K. Marshall. Results of considerable morphological in-
terest were embodied in a paper by Mrs. O. A. M. Hawkes
on the cranial and spinal nerves of the shark Chlamydo-
sdachus. Two mammals, a cat and an elephant-shrew,
collected by Major Powell-Cotton in the Ituri Forest of
Central .Africa, were discussed by Mr. Lvdekker, who also
described a race of the bruang, or Malay bear, from Tibet.
Finally, Sir Charles Eliot furnished a supplemental com-
munication in regard to the nudibranchiate molluscs of
Southern India.

At the meeting of the same Society on January 15, 1907,
the following papers were down for reading : — On a col-
lection of mammals from Annam, by Mr. T. L. Bonhote ; on
the " bleating " or " drumming " of the snipe, bv Mr.
P. H. Bahr ; on new or little-known marmosets from
.Amazonia, by Dr. E. A. Goeldi ; and on the classification
and anatomy of certain squamate reptiles (snakes and
lizards), bv Air. F. E. Beddard.

Febrtary. 1907 1

KNOWLEDGE & SCIENTIFIC NEWS.

43

CORRESPONDENCE.

Phenomenal Sunsets.

To the Editors of " Knowledge & Scientific News."

Sirs,— On Mondav, Julv 11, 1904, the sun set at 8.13, in
a clear sky in the west, though in the south-east a heavy
Ihunderstorm was worlcing up.

.\bout 8.30 p.m., from a light orange glow, there issued
five distinct bands of light of a pale salmon-pink colour,
which radiated like the spokes of a wheel from the sun,
being definitely separated' by five corresponding bands of
pale blue.

The phenomenon lasted for nearly an hour, the bands
graduallv fading away.

The same night a violent thunderstorm broke over Ex-
mouth.

On Mondav, Julv iS, a similar sunset occurred, though in
a modified form, which I saw from Okehanioton, but the
" bands " were reduced in number, though they had in-
creased in width.

The following day a heavy thunderstorm broke over the
town.

I saw a tliird sunset a few days after, which was limited
to one broad band of salmon-pink light, slightly inclined tc
the right of the sun.

About the same time thunderstorms and heavy rains oc-
curred in Paris, and a remarkable phenomenon was seen
in the sky on the morning of July 25, between nine and ten
o'clock, numerous coloured circles appearing round the
sun, like haloes.

Faithfullv vours,

C. S'OMERVILLE W.\T.SO\.

Battersea Park, S.\\'.

Basaltic Columns.

To the Editors of " Know i.i;noE & Sc ientific News."
.Sirs, — .May I refer those who are interested in the forma-
tion of concretionary masses from organic nuclei to a com-
munication on the subject which appeared in the (Icoloqieal
Maiaziiie of August, 1892? I have not, as yet, had reason
to change the views expressed therein.
Vours very faithfullv,

cecil'c.vrls-wii.son.

Royal Societies Club, S.W.

The "Flight" of Flyingr Fishes.

'I'o tiic Editors of " Knowi.edc.e .V Scientuu- News."
-Sirs, — The question of the flight — so called— of living
fishes is brought up again by the interesting notice of Colonel
Dunford, who has not, however, in my opinion, made out
his case. During twenty years passed at sea, and at inter-
vals since then, I have soeci.-dly studied this mailer, and
I am convinced that the fish does not, and cannot. Ilv as
birds do.

The flving fish projects itself into the air by means of its
powerful tail, and it is sustained there, often for a consider-
able time, by the extension of its large pectoral fins. A
rise in the " flight " may sometimes be noticed, but that
is merelv due to a heave given by the air forced up by a
wave crest. The fish, which apparently floats in the air
at an angle of 35° with the sea level, will be seen to fall
into the water, but instead of getting submerged, it
receives a fresh impetus and again projects itself upwards.
The active little anral fins assist the tail, but the pectoral
fins are incapable of other movement than the fore and aft
motion, which exiends them when the fish rises from the
water, and folds them close to the body when it swims in
the sea.

In a calm sea flying fish are seldom noticed out of the
water, and when they are the " flight " is extremely short,
nothing more than a jump, in fact. As a rule, the fish
flics up against the wind ; should it catch them sideways they
go off at a tangent, and a breath of air from an unexpected
quarter will often turn them right over.

I had a flving fish alive for a time, and was able to study
the motion of the fins in water. Out of water, the pectoral
fins soon get quite dry, a fact which would of itself be a
bar to real flight.

It is useless to look for information which mipht be
turned to practical application in the construction of aero-
machiues by the observation of the movements of flving
fishes. It is, however, quite possible that much mi'rht be
learned from observations of the flight of the albatross and
kindred birds.

Faithfully yours,

D. WILSON-BARKER, R N.R.

H.M.S. JTorcrsfer, Greenhithe.

Average Rainfall.

To the Editors of " Knowledge &. Scientific News."

.Sirs, — Assuming the rainfall during the first six months
of the year has far exceeded the average, is it not fair argu-
ment to assume at the beginning of the second six months
that the remaining rainfall for the year will be deficient?

Faithfullv vours,

R. M.
[From an analvsis of the Greenwich rainfall records, for
the 91 years 1815-1905, it appears that the rainfall for the
first half of the year was above the average on 43 occasions ;
of these, the rainfall of the succeeding six months was above
the average on 20 occasions, but below it on 23. There
does not seem to be any reasonable data for founding a
forecast of the coming season from these figures. — W.M.I

Brakes.

To the Editors of " Knowlkix.e & Scientific News."

Sirs, — The action of railway brakes was investigated
at considerable length in a paper published a few years ago
by Professor A. Sommerfeld, of the Technischc Hochschule,
.\achen.

I cannot lay hands on my copy at the present instant, and
should, therefore, not have referred to the matter hut for
the very inconclusive arguments used in the discussion !n
Vdur columns. .\ reference to the paper appeared in Kafiit-'.
at the time, and I have no doubt Professor SommerfeiJ
would send a reprint to anyone interested in the matter.

A complete investigation requires account to be taken of
the differences which exist between the co-eflicients of rolling
and sliding friction, and the fact that the co-eftlcient of
sliding friction depends on the relative velocity of the parts
ihat ore sliding on one another. These dilTerences arc not
mentioned in elementary text-books, and the data requiro-J
for solving the problem are necessarily based on the results
of experiment. I am practically certain that Professor Sont-
metfeld found that the maximum efliciency was not in
general obtained when the wheels were locked.

G. 11. BR^.\N.

44

KNOWLEDGE & SCIENTIFIC NEWS.

[February, 1907.

REVIEWS OF BOOKS.

ASTRONOMY.

Sixth Report of the Section for the Observation of Vari-
able Stars (Mrmiiirs o( llu- 15iili'-li .\--liomiinu:il AsMuialiiiTi,
Vol. XV., pp. 140 with 14 plates; price to non-members js.).
- — Of the nimurous observinpf sections of llie n..\..\. the
variable star .section, uniler the enerf,'elic direction of Col.
MarkwicU, is by no means the le.ist lloiirishinjj^. X'ari.ible
st.ir observation does not necess.irily require any expensi\c
outfit, anil is, therefore, peculiarly attractive to workers un-
provided with a telescope, or with only a sm.ill one, especi-
allv since the discovery of Nova Persei. The perioil covered
bv the present report is the lustrum 1400-11)04, .ind a few
previous observ.ilions are included. The work has
naturallv bei-n confined to fairly well-known vari.ible st.irs,
of which 2(1 " lonij-period " anil two " irretjular " v.iriables
provide the whole of the 5,717 observations. The director
himself, usinij a telescope of 2,"-inch aperture, is responsi-
ble for more than 2,000 of the number, so lh;it he is some-
thinjj more th.'in an armchair director. Of the sl.irs in the
list, X Cvijni is, perhaps, tlie best observeil, with 508 ob-
servations bv 13 observers. Harvard mai^^nitudes have been
used for the comparison stars whenever |)ossible in order to
make the results strictiv comparable with those of Harvard
Collefje Observatory. The observ.ilions have been printed
very fully, each day and each observer beinij given
separatelv in every case, and the resultihpf mat^nilude com-
p.'ired with th;it c.-ilculaled. The plates tjive the results in
di.ij^-rammalic form with dots for measures and curves for
observed and calculated light-curves. The labour involved
in the comiHil.ilions and preparation for press must have
been considerable, and in this the director acknowledges
valuable assistance from Mr. C. L. Brook, who also con-
tributed largely towards the expense of printing, which
would have been too great for the .Association, but which
was met bv gr.ants and subscriptions from the .\ssociation
and the Roval Societv (Government Grant Committee),
and two of the observers, Messrs. Brook and W'orssell.

Astronomical Calendars for 1907. — We have received from Mr.
Arthur Mee, of Llanishen, Cardiff', a copy of his " Heavens at a
Glance, 1907," price yd., post free. On the one side appears two
star maps, which, to use Mr. Mee's own words, are "intended
only for those who have no access to a planisphere or a
celestial globe or atlas," and on the reverse a calendar for the
year together with useful astronomical information.

Also received, too late for notice in our last issue, was
Hirschfeld's Star Calendar (Hirschfeld Bros., Ltd., Furnival
Street, is. net) for this year. This consists of the 4 cards, as
in previous if sues, each card giving a rough but clearly
marked chart of the constellatioDS for three months, also a
monthly calendar.

BOTANICAL.

New Creations in Plant Life, by W. S. Harwood (Mac-
millan and Co.). — Mr. Harwood is obviously to a great
extent blinded by hero-worship, and his knowledge respect-
ing fhe creation of plants, as he is pleased to style what is
usually known as hybridisation, appears to be mainly con-
fined to the work done by Burbank, otherwise the introduc-
tory remark that his hero " is the foremost plant-breeder in
the world," and that " he has produced more new forms of
plant life than any other man " would have been to some
extent qualified. Burbank has undoubtedly done some
good work, and has given to the world many improved
plants of sterling value, and a straightforward account of
his accomplishments and methods would have been wel-
comed by all, but unfortunately such practical matter is
completely swamped by a superabundance of rhetorical
flourish that the subject proper is somewhat difficult to
locate. " Speaking of making a blue rose, he (Burbank)
said it was one of the easiest things in the world if one
should set out diligently about it, but it would consume verv
>nuch time in the making, and it would be doubtful after all
if it added much to the charm of this rare flower. He ha;
studied the rose with great care, and he has seen in the
consideration of its colouring an easy avenue to a land of
blue roses." We sincerely trust that Burbank mav be
induced to reconsider his decision, and make a blue rose;
many people have already attempted to do so, but without

success. Kverybody desires a blue rose, .inil if the only
person in tlie world cap.'ible of creating u\n: declines to do
so, the oppoiUmity will probably be lost fur ever. We arc
told that Burb.ink li.is cle.irly demonslrated the utter
f.ill.icv of the Meiidelian L.iws, ;md has ;ilso brought to
light the absurdily of the gener.ally ;icknowl(dged statement
that " .acquired characters .-uc never transmitted." On the
other h.iiul he has established the opposite, that acquired
characteristics are the only ones that .are transmitted.
I'uller details on these points will be awaited with interest.

CHEMICAL.

Practical Physical Chemistry, by .\. hindl.iy, M.A., rh.D.,
O.-Sc, pp. xii. .inil ^Sj (London: Longm.ins, Green and
Co. ; 4s. ()d.) Most ilemenl.uy books of chemical analysis
include a number of physical exercises, such .is the deter-
mination of the specific gr.avily, molecul.ar weight by diCfer-
enl methods, .and so on ; but we know of none which deals
solely with the physical side of the science. 'I'here are, it is
true, several large manuals, such as Ostvvald's text book,
but these are far loo .advanced for the beginner, and hence
there is every reason for the existence of a book like that of
Ilr. Findlay which sh.ali serve as ;i |jractic:il physical guide
to the general student of chemistry. The work includes
chapters on density, thermal .and optical measurements,
molecular weight, electrical conductivity, electromotive force,
.and the velocity of chemical reaction. It is very clearly
written, and in each case good descriptions with illustra-
tions of the necessary .apparatus .are given, together with
lesl exercises in the use of this ap|);iralus. The author, who
is a lecturer on physical chemistry in the L'niversitv of Bir-
mingham, is to be congratulated on the success of his at-
tempt to provide a suitable lillle text book for use in
schools and universities.

Problems in Animal Metabolism, by J. B. I.eathes (Lon-
don : Murray, igob; pp. viii +205 ; price 7s. 6d. net). — That
the contents of this little volume— which is practically the
report of a course of lectures given in the Laboratory of
London LIniversity, a couple of years ago — are thoroughly
to the point and up to date, we have not the slightest doubt.
H, however, the work is intended to appeal to any other
class of readers than the student — and students of a rathct
specialised type — it should have been written in a much
less " cut-and-dry " style. When we first opened it, ws
hoped to find in this volume a readable account of the won-
derful chemical processes which are constantly taking place
in the human body. To our great disappointment, we
found that llie book is absolutely unreadable except by a
professed chemist and physiologist. Had the author but
taken as his model the admirable articles on the " New
Chemistry " which have recently appeared in the Cornhi!'.
Magazine, he might have produced a work which
would have been an acceptable and useful one to scientific
men who are not specialists in chemistry and physiology, as
it no doubt is to those who devote their attention to these
blanches of science. The author's style is also capable of
much improvement ; the commencement of two consecu-
tive sentences on page 31 with the word " but," being a
glaring example of one of his common failings. As we have
said, the work is, no doubt, admirable for students of meta-
bolism, but it may be hoped that in a second edition it will
be so modified as to meet the requirements of a wider circle
of readers.

METEOROLOaiCAL.
Meteorology in Mysore for 1905. Thirteenth Annual Re-
port, by John Cook, M..\., F.R.S.E. (Bangalore, igo6;
4to 56 pp. and 8 pl.ates). — This volume contains the results
of the meteorological observations made at Bangalore
(3,021 ft.), Mysore (2,518 ft.), Hassan (3,001 ft.), and Chital-
drug (2,405 ft.) during the year igo5. 'Lhe following are
the averages of some of the results for the thirteen years
1893-1905 :—

Bangalore. Mysore. Hassan. Chilaldrug.
Temperature- 00^0

Mean 740 75-5 721 76-8

Mean Maximum 84 9 S64 83-2 87 o

,, Minimum 64-4 65-8 62-4 tty-i

Daily Range 20'5 206 20-8 ig-6

Rainfall-
Total ... ... 34'68ins. 30-77iDS. sS'ijins. 2522ins.

No. of Rain Days 104 103 124 Sg

February, 1907.]

KNOWLEDGE & SCIENTIFIC NEWS.

45

Observations and Investigations made at the Blue Hil

Meteorological Observatory, Massachusetts, U.S.A.. in the
years 1903 and 1904, undi.r the direction of A. Lawrence
Rotch (Cambridge, 1906; 410. 74 pp.).— The Blue Hill Ob-
servatory- was founded by .Mr. Rotch on January 30, 1885,
and the main object of its existence is scientific research.
Intimate relations have been cultivated with foreign meteoro-
logists and institutions, and Mr. Rotch has attended the
.Meteorological Conferences held in Europe, and the meet-
ings of the International Cloud Commission and of the
Commission for Scientific .\eronautics, of both of which he
is the American member. The exploration of the air by
means of kites and lifting instruments, which record continu-
ously, was originated at Blue Hill in 1.S94, and great atten-
tion'has been paid to this subject ever since. The present
volume (which forms Part H. of Vol. LVHI. of the AnnaJs
of the Asironcmical Observatory of Harvard College) con-
tains the observations made twice daily in the years 1903
and 1904, and also the results from the kite meteorograph
and simultaneous records at the ground. In addition there
are the following papers : — (i) Unusual Sky-Colours, by
Mr. -A. L. Rotch; (2) The Effect of .Meteorological Condi-
tions upon Optical Refraction in the Lower Atmospheric
Strata, by Mr. L. .\. Wells; and (3) The Errors of Absorp-
tion Hygrometers, by Mr. S. P. Fergusson.
MICROSCOPY.
The Principles of Microscopy, by Sir .\. E. Wright, ^LD.,
F.R.S., &c. (London : .\. Constable and Co., Ltd., 1906,
xxii. and 250 pp., iS plates and 97 figs, in text; price 21s.
net.). — With Sir A. E. Wright's intention in writing this
book we are in complete sympathy. There can be no doubt
that users of the microscope as a body are content with too
much ''rule of thumb " and too little " reasoned action,"
and that they fail accordingly to get the best results out of
their instruments, even where such results are imperatively
necessary to them. In endeavouring to persuade the worker
with the microscope that his methods are capable of im-
provement, and in leading him up to such improvement by
a careful enunciation of principles, based upon demonstra-
tion and experiment, Sir .\. E. Wright has done much-
needed work. It is, however, somewhat doubtful whether
he has not over-shot the mark and gone over the heads of
the larger audience whom he would no doubt have wished
to reach. In the first place, the book, beautifully printed
and illustrated though it is, is unquestionably costly, and
this alone would limit its usefulness ; in the second place, it
may be questioned whether it does not deal too much with
principle and too little with practice to attract the average
worker. In this connection it must be borne in mind that
the book is admittedly written for the " rule of thumb "
worker, and not for the student of microscopical optics, but
the average worker, unfamiliar with optics, would find it
dillicult to follow or appreciate the sequence of the reason-
ing, or to realise where he was to get his equivalent return
for the " intellectual effort " which the author demands of
him. The method of dealing with the subject is unfamiliar,
and the phraseology, and sometimes even the words, more
unfamiliar still, but the experiments are of the simple and
easily performed, yet ingenious and instructive, character
which we have learned to expect of the author. The optical
principles, however, gain largely as addressed to the
ordinary reader, from an almost entire avoidance of mathe-
matic.'il expression, and the exposition of them leaves upon
the technical reader an impression of much originality. It
is in the practical ap|)lications of the theories so carefully
built up that the worker will find most disappointment,
inadequacy, and in some instances even misdirection, as
where he is instructed (on p. 174) to use a plane mirror
with the sub-stage condenser with daylight, and a concave
mirror with lamp-light ; to obtain a " sharper " image by
cutting down the condenser beams " severely " with the
diaphragm ; and by statements that a too thin cover-glass is
corrected for by shortening the body tube, and a too thick
one by lenethening it (p. 20^). The author appears to con-
sider the .\bbe condenser witVi its enormous spherical and
chromatic aberrations as effective as an aplanatic .and
achromatic condenser, and vet we see him in Chapter xv.
endeavouring to get rid of the aberrations caused by the use
of the former condenser combined with a concave mirror
and an incandescent l.imp, by culling down the beams from

the latter by a screen placed immediately before it, the
lamp being apparently placed so close to the microscope as
to be in the principal focus of the concave mirror. Methods
of measuring the magnification of an object — though atten-
tion is not called to this — and the magnifications of ob-
jectives and eyepieces are dealt with in original ways, which,
however, seem to us to have no superiority over the better-
known but untouched-on methods. The author very frankly
expresses his indebtedness to Mr. J. W. Gordon for much
help and suggestion, but undue prominence would seem to
be given to the latter's very interesting and ingenious, but
noiie the less still debatable, theories. In particular, it
would have been well if Sir A. E. Wright had laid greater
stress on the limitations of Mr. Gordon's much-advertised
method of improving the image given by high-power
oculars, and his own appraisement of the " achievement "
that it may " carry us to a higher limit of resolution " by
enabling the optician to correct his lenses somewhat more
easily! It would save much irresponsible talk as to a
newlv-realised magnification of 10,000 diameters, coupled
with suggestions that Mr. J. Butler Burke's " radiobes "
should be inspected by them without delay I
PHOTOGRAPHY.
The Complete Piiotographer, by R. Child Bayley
(London: .Methuen and Co.; price los. (>d. net.). — This is
the fourth volume of a series of which " The Complete
Motorist," "The Complete Golfer," and "The Complete
Cricketer," are the other three, but there is nothing of a
sporting character in it. It is a straightforward treatise,
beginning with historical matters and concluding with
chapters on pictorial photography, exhibitions, and societies.
It is neither an instruction book nor a guide to the science
of the subject ; it includes, as the author himself says in the
preface, very few formulae, and yet it contains a great deal
ot information .set down in a rather diffuse, but eminently
readable style. Every few pages there is a reproduction of
a notable photograph, printed on special paper, and of these
there are more than sixty, intended presumably to show the
reader some of the best work, that he may know the sort
of result that he should aim at. The frontispiece is a fine
photogravure portrait of Henry Irving, by William
Crooke. After about four hundred pages of subject matter
there follows a very copious index. .As already stated, it
does not claim to be what is generally understood as a
student's book. He who seeks information on any particular
subject will almost certainly find a suitable entry in the
index, and on turning to the page indicated he may learn
much, but, on the other hand, he may find that the subject
is merely talked round, or that it is summarily dismis.sed
with a mere reference, or an expression of disapprobation.
The author holds some views that other authorities would
regard as unsound, as, for example, that levels on hand
cameras are of very little use because they cannot be seen
at the same time as the finder, and that for architectural
work they arc not sensitive enough. Doubtless, this is oc-
casionaliv true, because of bad design or inferior workman-
ship, but it ought not to be so. On the whole, the advice
given is good, and in those cases where one is inclined to
disagree with it, it is entitled to respectful consideration
because of the experience of the author. Those who like
reading about photographic methods and similar subjects,
and arc tired of the innumerable little guide books that are
constantly being produced, will appreciate this volume, for
it is essentially a book to be re.ad, rather than a work of
reference.

ZOOLOGICAL.
We have to acknowledge the; receipt of a copy of an article
0:1 •• Snake Feeding at the Zoo," reprinted from the January
number of the Humaiiifarian Hcvinr. The practice ot
feeding these reptiles with living animals is strongly con-
d'^mned ; and it is urged, on the authority of the Director
of the New York Zoological Park, that " dead meat " will
equally well serve the purpose.

MISCELLANEOUS.
The Scientist's Pocket Book and Di.iry (James WooUey, Sons
aivl Co., Ltd.. M.inchester ; is., cloth; (k1., pajxT cover). —
This is a capital little book, containing a number of useful
tables in all branches of science, and a diary with a week on
a page.

46

KNOWLEDGE & SCIENTIFIC NEWS.

[February, 1907.

Conducted by F. Shillington Scales, u.a., f.r.m.s.

Royal Microscopical Society.

DlxKMHKK iq, Dr. 1). II. Scott, l'M\..S., l>i(.-si(l(.'iii, in
the chair. Mr. C L. dirties pro.v.'iitccl to the .Society
:i dissectiiii^ .stanil, made by the htto l.atiiinr
Chirke, C.K., and a li\c-box. Mr. Conrad Hock ex-
hibited a new form of hand demon.stralion microscope
for low-power objecl.s for use in clas.ses. .Sonie slide.s
.selected from the collection presented to the Society 1)\
Mr. Jas. Hilton, were also exhibited. Mr. S. Rogers
re.'id a paper on " Microscopic Study of Strain in
N'etaLs," which showed the nature of the fatifjuc of
steels under alternating strcs.scs of a certain magnitude.
He finds that the nature of the effects in the ferrite of
steels is different from that in soft iron, and the effects
in pearlite depend upon the type of pearlite. It might
be expected that incipient cracks would tend to select
a cour.se largely through ferrite, but important re:isons
show that caution should be exerci.sed in accepting thi.s
hypothesis, and much experimental work confirmed the
fact that the .selection, though marked, is by nO' means
exclusi\e. An important difference exists between
;;tcels rolled or annealed below about 750° C, and those
anneak-d at higher temi>eratures, i.e., more or less
overheated. In the former, the outcrop of surfaces
upon which slip has repeatedly occurred are very
numerous, short and crooked, and the surface parallel
to the direction of stress becomes ruffled. In the latter
type, the outcrops are fewer, less crooked, and longer,
and the surface is practically unruffled'. A relation is
found to exist between lines which are found upon
statically strained pieces, and this leads to the theory
that specimens of the "normal " group endure fatigue
better than " overheated " specimens, because the per-
manent and injurious micro.scopic strains are more
minutely sub-divided and uniformly distributed in the
former than in the latter. It is conclusively shown that
there is a stage in the life of a piece of steel enduring
fatig^ue after which, though it is far short of final rui>
ture, annealing is futile, if not actuallv harmful.
Pieces in this stage, if heated to 250" C, or higher, and
then fatigued to rupture, show heat tint-marks on the
ultimate fracture, w hich map out the portion of fracture
which was sufficiently open at the time of heating for
air to enter.

Quekett Microscopical Club.
December 21. Mr. W. R. Travi^s fxhibited and
described an expanding central stop for dark ground
illumination. Mr. A. A. C. Eliot Merlin, F.R.M.S.,
communicated a paper on " New Diatom Structure."
This dealt chiefly with the recent resolution of " veiled "
m.-irkings on some thre^e species of Mclosira, and new
.';econdary markings in species of A'avia//c2, H ralodncHs.
Aiilodisais, etc. The author had also sent for exhibition
two. dark-ground photographs of Triceratmm nova
Zcalandica, x 490, taken with a Zeiss 16 mm. apoch-
romat, N..'\., 0.35, and a Powell 26 projection eyepiece.
The focus in both ca.ses was adjusted on the image of
the apochromatic substage condenser stop, formed in

the central areolations, and the single bar arm of the
central stop was well seen in many areolations of both
specimens.

The meeting was preceded by a drmonstralion on
" Dark Ciround Illumination," by Mr. II. V . .Angus. It
was stated that to .secure the best results, the nunn'rical
apertures ol objeclixe, conden.ser, and stop, should lia\e
the ratio respectively of i, i, :md i, e.g., if the ol)jecli\e
has N..\. 0.33, the v.alue of the central stop should In-
0.50, and the conden.ser, N..\. i.o. Methcxls of deter-
mining the N..\. \aliie of the conden.ser and of the stop
ret|uirjd were given, and the rules laid down were illus-
trated by a number of specially arranged microscopes.
Collecting- and Studying- Flustrclla
Hispida.

In the "Quarterly Journal of Microscopical Science "
R. M. Pace gives a method of study of the larval
development of Flustrclla liispii/a which may be of ser-
\ ice in other directions. The material was collected on
the South Coast, being found abundantly between tide-
marks on tiicus, and t)Ccasionally on other algie. l''or
the study of larval development, colonies of one or two
scasotts' growth taken close to low water-mark proved
the most suitable. .Such colonies contain abundance of
spermatozoa, or of ova or larvte, according to the
season, the reproductive period being from i""ebruary
to August. In pure running water t'luiirclla hispida
may be usually kept alive in tanks for a few days to a
week. The larva; were examined in the living state
and after fixation; the fixatives used were: (i) Satu-
rated sublimate with 5 per cent, acetic acid; (2) 5 per
cent, chromic acid, 100 parts, with 5 drops acetic acid;
(3) Flemming; (4) Hermann; (5) Chromo-nitro-osmic
mixture; (6) .Vcetic alcohol, with sublimate to satura-
tion; (7) Kleinenbcrg. .After fixation, the material was
removed to 70 per cent, alcohol. Chrom-acetic acid
and corrosive acetic gave the best results for fixation
in bulk. Larvas were isolated by slicing off the front
wall of the colony with a razor; the larvEe lie just below
tills wall, enclosed in the tentacle-sheath. For isolated
larvte, the best fixatives were corrosive acetic and
acetic alcohol, saturated with sublimate. Kntire eggs
and larvEe were examined during life and after fixation.
The latter were stained with borax-carmine or with
saffranin. In some ca.scs the nuclear spindles and the
yolk-nucleus were clearly brought out. Sections were
made from isolated lar\-{e, and of colonics containing
larva-. Groups of isolated larvae w^ere embedded to-
gether, and sections obtained in various planes. In
order to determine the direction of unorientated larva",
a set of standard .sections was prepared by carefully
orientating single larvaB, which had been first studied
entire. To ensure thorough impregnation of colonies
with larva; in siiii, the material was left in xylol for
about a week before being passed through xylol-paraffin
to paraffin. The most useful stain for sections was
Heidenhain's iron-ha-matoxylin, followed by eosin in
90 per cent, alcohol. Other stains were u.sed, among
which was Mayer's muci-carmine, for detecting the
presence of mucin.

Differentiation of Typhoid Bacillus.

The " British Medical Journal " gives a summary of
a method advocated by Lcefl!ler for differentiating
typhoid bacilli from nearly allied organisms, by the
u.se of media to which malachite green has been added.
One of these media contains 2 per cent, peptone and
I per cent, nutro.se in loo c. cm. of distilled water, and
is neutralised bv the addition of t.o6 c. cm. of normal
potash. To this is added 5 per cent, of milk sui,Mr
and I p;r cent, of grape sugar. ,\fter boiling for a

February, 1907.]

KNOWLEDGE & SCIENTIFIC NEWS.

47

short time, and tlicn cooling to a gentle warmth, 3
c. cm. of a 2 per cent, solution of malachite green are
addetl. ^^■hen this medium is inoculated with typhoid
bacilli, and with other organisms belonging to the
typhoid family, striking differences are brought out-
In the typhoid tubes, the nutro.se is precipitated in a
qLiite distinctive manner. The fluid is coagulated like
acidified milk, and alcove the coagulated layer there is
a clear, green liquid. With the majority of the other
organisms, such as the Coli group, Gaertner's bacillus,
and paratyphoid bacilli, active fermentation takes place,
the precipitated nutrose adheres to the walls of the
tube as dirty, green flakes, whilst some of it is carried
to the surface by the gas formed, and floats as a dirty
green layer. When grape sugar is omitted from the
medium, only the Coli group cause fermentation, and
they can, therefore, be differentiated from the rest,
whilst other organisms have a reducing action on the
green, turning it a pale yellow, more especially when
the alkalinity of the medium is slightly increased. The
typhoid bacillus does not change the medium, but only
exerts a very gradual reducing action on the green.
The paratyphoid bacillus .\, on the other hand, turns
(he solution pale blue.

Journal of the Quekctt Club.
The last (NoAember) issue of the Journal of the
Quekctt Microscopical Club is in no way inferior to its
predecessors, and contains, amongst much other matter,
some most interesting notes and observations on the
life-history of fresh-water mites, by Mr. C. D. Soar,
from the cg^ to the larval, nymph, and adult stages ;
an illustrated paper by Mr. "Julius Rheinberg, on
" Stereoscopic Effect and a Suggested Improvement in
Rinocular Microscopes ; " and a lucid account by Mr.
D. J. Scourfield, of Mendel's " Law of Heredity," with
special reference to its relation to microscopy, which
any who are interested in this fascinating subject, but
have had little opportunity of studying it at first hand,
should read. The Laws of Mendel are very nrominent
just now amongst biologists, and have an important
relation, not only to our conceptions of evolution and
variation, but to many practical problems in economic
botany and geology which the general public will
realise with surprise when they are accomplished com-
mercial facts. There are the usual reviews, once more
restored to the Journal, reports of the Proceedings of
the Club, and a list of members and office-bearers,
together with some excellent plates and illustrations.
Microscopical Material.
Mr. J. Strachan, (if Hallyclare, has \ery kindly sent
me for distribution, some microscopic crystals of lead
chloride (Pb CI2). Mr. Strachan says : " The crystals
h;ive taken several months to grow, rnd are in the form
of rhombic plates, the usual form being that of rhombic
needles. They contain numerous cavities, similar to
tho.se found in certain rock-forming minerals. There
are also numerous undeveloped crystals, so-called
' crystal-eggs.' I find that Canada balsam is a ycry
suitable mounting nv.-diuni for crystals." I shall be
glad to .send some of these crystals tO' any reader who
caras to .send me a stampi'd addres.sed envelope, a small
tin box (they are easily crushed'), and the coupon to be
found in the advertisement columns of this issue of
" KNOWi.ivDr.F.," but I must warn applicants that the
amount of material is \iry small, and they will only
receive a very small quantity accordingly.

Notes and Queries.

Qiiilitt ^firriiscnpiiiil Cliih. Mr. Mmlaiul, h;iving given
in> Ihi' iKisI of IIiMior.ux li-r.-i^urcr lo llic (Jurkrll Ckib, the

Committee have appointed Mr. Frederick J. Perks, of 48,
Grove Park, Denmark Hill, S.E., as Treasurer in his place
as from January i, igoy. All subscriptions and other pay-
ments, together with notices of change of address, should,
therefore, for the future be sent to Mr. Perks, as above.

C. J. I). (Hatjwar(Vs Heath). — I cannot lay claim to any
special legal knowledge, but I do not see how there can be
any copyright in microscopic slides as such. It would be as
reasonable to suggest that there is a copyright in a stuffed
animal. Therefore, there can be no reason why you should
not photograph or draw any slide you like, whether pur-
chased or not, provided it is your own, failinsj which it
would, of course, be at least courteous to ask the owner's
permission to do so. Having photogi^raphed it, the usual laws
of copyright will apply to the photograph or to the drawing
when published.

F. R. H. S. (Munirh). — It would be impossible to say
whether the times recommended in any book on Human
Histology for fixing animal tissues are equally applicable
to vegetable tissues, without knowing what fixatives and
what materials are referred to. Generally speaking, a book
on Human Histology would be a very unsatisfactor)- guide
to the preparation of vegetable structure. There are so
many modifications, but in nearly all cases the most fre-
quent causes of f.ailure are insufficient time in fixation and
insufficient washini^ afterwards. It would be better for you
to |)rovide yourself with some well-known practical text-
book, like .Strasbursjer's " Das Botanische Praktikuni."

T. H. H[. (Hnr/ley). — Vou will find very full instructions for
the collecting and preparing; of foraminifera in " Know-
ledge " for January and February, iqo2, in a couple of
articles written bv Mr. .\. Earland. Briefly sunimari.sed, it
is necessary to wash and sort the material before proceeding
to mount it. The material distributed last month has been
already washed, but it will be convenient to pass it through
gauze wire of various meshes. Mr. Earland recommends
two sieves 40 and 120 meshes to the inch, the diameter of
the apertures in the latter being about 3iii of an inch. It is
necessary to " float " and " rock " the material. The
" floating " is done in bright daylight, t|ie material being
slowly poured into a jar of water. The sand sinks most
readiiv, and the more slowly following foraminifera are
then rapidly tilted over and through the finest sieve. By
this means the material is roughly sorted. The " floating "
is best done in a phototjraphic developing dish, the residuum
being placed in this for a depth of .ibout a qu;irter of .an
inch and covered with about three-quarters of an inch of
water. By rocking and circular movements the foramini-
fera are suspended in the water and manipulated into one
corner of the di.sh, whence they are suddenly tilted into
the sieve. The material must then be dried, and the
foraminifera selected under the microscope, for which pur-
pose Mr. Earland recommends a little shallow tray covered
with coarse black-ribbed silk to keep the for.iminifera from
rolling about, the specimens beinir selected Iw means of a
fine sable brush moistened with the lips, and then transferred
to a prepared cell or slip.

.\s fixative for mounting, Mr. Earland recommends gum
tragacanth, which is almost invisible when dry, and free
from the objectionable glaze of gum arable, and also less
subject to variations of moisture in the air. He adds that
the same gum, diluted to a watery consistency, can be
u.sed as a fixative for foraminifera before mounting in
balsam, the gum, which must be thoroutjhlv dried, being
quite invisible in b.ilsam. Dry mounts can be m.ade in a
similar way, the foraminifera beintj mounted between two
cover-glasses, the lower one beintr blackened before lieintj
fastened to the slide, and the whole ringed round in the
usual way. My own method is to mount all opaque ob-
jects with tr.-msparent backgrounds, and to have one or two
plain slides with circular discs of dull black paper fastened
on them which I can place behind the slides when I wish to
illuminate them as ojiaque objects. By these means obiects
such as foraminifera, mounted dry, can bi' illuminated from
above ;is opaque objects, or from below with annular (dark-
groimd) illumination, as required.

[CommiinicalioiK and inquirits "» Micrtscot-iciit niiilttn shoii'ii h'
addressed to F. Sliillington Siiiles, " Jersty." St ftarniihis Road,
Canihridse. Cfrrrsf'ondfnt^ are requested not to se'id stecw'etis to fr'

iuimed .\

48

KNOVVLKDGE & SCIENTIFIC NEWS.

I February, 1907.

The Face of the Sky for February.

By VV. SiiACKLETON, F.K.A.S.

The Sun.— On the ist the Sun rises at 7.42 and sets at
4.46; on the 2Sth he rises at 6.51 and .sets at 5.35.

Sun-spots may occasionally be observed, thouj^h they
are not very numerous; solar activity appears to be
diminishing, though at the time of writing there is a
large scattered group visible.

■Phe position of the Sun's axis and of the centre of
the disc is shown in the following table : —

Date.

Axis inclined
from N. point-

Centre of disc

S. of Suns

Equator.

Heliographic

Longitiidr of

Centre of Disc.

Feb. 5 . .

:; I" ::
,, 20

.. 25 ••

Mar. 2

is" 41 'W

15° 36'W
17° 22'W
19° o'W
20° 29 'W
21° 49'W

6° 20'

6° 37'
6" 52'
7= 2'
7° 10'
7° 14'

37° 5'
331° '5'
265° 25'

190° 34'

133° 43'

67° 51'

The Moon

—

Date.

Phases.

H.

M.

Feb. 6 ..

,, 12 . .

20 . .

,, 28 ..

•

Last Quarter
New Moon
First Quarter
Full Moon

0
5
4
6

52 am.

43 P-m-
35 a m
23 a.m.

Feb. 10 ..
,, 22 . .

Perigee

Apogee

7
0

6 a.m.

54 a.m.

OCCULTATIONS :-

e.

Star's
Name.

6

1

'c

Disappearance.

Reappearance.

Moon
Age

Da

Angle

Angle

's

rt

Mean

from N

Mean

from N.

Time.

point.

Time.

point.

d.

p. m.

p. m.

li.

Feb.

21

i Geminorum . .

var.

7 II

70°

8 29

288°

II

2

^■(

85 Geminorum . .

S'S

7 7

50°

» 5

316°

12

I

•■

25

6 Cancri . .

4 2

5 30

69°

b 31

302°

13

0

The Planets.— Mercury (Feb. i, R.A. 20" 55"";
Dec. S. 19° 35' ; Feb. 28, R.A. 23*= 46"" ; Dec. S. 0° 9')
is in superior conjunction with the Sun on the 2nd and
hence during the early part of the month is unobserv-
able. Towards the end of the month the planet is an
evening star in Aquarius and Pisces setting at 6.38 p.m.
on the 20th and at 7.20 p.m. on the 28th.

Venus (Feb. i, R.A. i7'» 39m; Dec. S. 19° 23';
Feb. 28, R.A. 19" 38-" ; Dec. S. 19° 30') is situated
in Sagittarius and is a conspicuous object in the morn-
ing sky, rising at 4.38 a.m. on the ist. The planet is
at greatest westerly elongation of 46° 53' on the gth
when it rises at 4 43 a m. ; on this date the telescope
appearance is that of "half moon" -5 of the disc being
illuminated.

Mars (Feb. i, R.A. i^"" 43" ; Dec. S. 18° 49' ; Feb. 28,
R.A. 16'' 47"; Dec. S. 21" 51') is situated on the con-
fines of Libra and Scorpio and rises about 2.30 a.m. on
the 14th. The apparent diameter of the planet is in-
creasing as the opposition, which takes place in July,
approaches.

Jupiter (Feb. i, R.A. 6^ g'" ; Dec. N. 23° 25' ; Feb. 28,
R.A. 6'' 41" ; Dec. N. 23° 29') is a very conspicuous
object in the evening sky and is describing a short retro-

grade"path near7the]star v Geminorum. On^ the 25th
ihe planet is at the stationary point. Throughout the
month the planet is well placed for easy observation in
the evenings, being due South at 8.30 p.m. on the 14th.

The equatorial diameter on the 15th is 42"-y, whilst
the polar diameter is 2"-8 smaller. On the evening of
the 22nd the Moon is in conjunction with the planet at
6.37 p.m.

The following table gives the satellite phenomena
visible between 6 p.m. and midnight : —

6

d
g

B

0
c

P.M.'s

H. M.

&

6
in

c

0

c

V

c

<U

a.

I'M.'s

H. M.

6

(0

Q

n

1
0

£

0.

PM.'s.

H. M.

Feb.

Feb.

Feb

I

III

Oc. D.

9 28

12

III.

.Sh. F.

10 6

21

II.

Sh. I.

7 38

3

II.

Tr. I.

1 1 18

I.

Tr. I.

11 23

I.

Ti. I.

7 40

S

III.

Sh. E.

6 5

n

1.

Oc. n.

8 35

II.

Tr. E.

8 9

II.

Oc. D.

6 6

I.

Fc. R.

II 52

I.

Sh. I.

8 48

I.
I.

Tr. I.
Sh. I.

9 35
10 20

> 1

I.
II.

.Sh. I.
Sh. F.

65.3
7 52

I.
II.

Tr. F,
Sh. E.

9 57
10 30

n.

Ec. R.

10 .|i

I.

Tr. F.

8 7

I.

Sh. F.

II 5

I.

Tr. E.

II 52

I.

Sh. F.

9 10

22

I.

Ec. R.

8 17

6

I.

Oc. D.

6 47

■ 5

I.

Fc. R.

6 21

26

Ill

Tr. I.

10 12

I.

F.C. R.

9 57

18

IV.

Tr. 1-1.

6 26

28

II.

Tr. I.

7 49

7

I.

Tr. E.

6 ig

19

in.

Tr. I.

6 3,

I.

Tr. I.

9 30

I.

Sh. E.

7 15

III.

Tr. F.

9 .33

II.

Sh. I.

10 16

10

IV.

Ec R.

7 25

II

Oc. 0.

10 "51

II.

Tr. E.

10 39

12

III.

Sh. I.

e 57

III.

Sh. I.

10 57

I.

.Sh. I.

10 43

II.

Oc D.

8 28

20

I.

Oc. U.

10 25

1.

Tr. E.

II 48

" Oc. D." denotes the disappearance of the Satellite behind the disc, and
" Oc. R." its reappearance ; " Tr. I." the inj^ress 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 ; " Ec. D." denotes disappearance of Satellite
by Eclipse, and " Ec. R." its reappearance.

Saturn (Feb. i, R.A. 23^ 2"^; Dec. S. 8° 14';
Feb. 2S, R.A. 2311 13™ ; Dec. S. 7° o') is only observ-
able for a short time after sunset, as he sets at 7 p.m. on
the 14th. The ring, as seen in the telescope, appears to
be nearly closed and we almost have an edge view; the
northern surface of the ring is visible at angle of only
3'-^ to our line of vision.

Uranus (Feb. 14, R.A. 18^ 48-"; Dec. S. 23° 18')
is a morning star, rising about 6 a.m. at the beginning
of the month.

Neptune (Feb. 14, R.A. 6" 44™ ; Dec. N. 22° 10') is
situated in Gemini not far from the star 36 Geminorum.
On the 14th the planet is due South at 9.15 p.m.

Meteor Showers : —

Date.

Radiant,

Near to

R A.

Dec.

Feb. 5-10 . .

15-

,, 20 . .

h. m.
5 0

15 44
12 4

+41°
+ 11"

+ 34°

ri Aurigae
a Serpentis
Cor Caroli

Slow: bright.
Swift ; streaks.
Swift ; bright.

Algol may be observed at minimum on the 9th at
10.3 p.m., and on the 12th at 6.52 p.m.

Double Stars.— Casloy, separation 5"-6, mags. 27,
37. Excellent object for small telescopes. The brightest
pair to be observed in this country ; can always be relied
upon as a good show object.

K Geminorum, separation 6"-3, mags. 4, 8'5 ; very
pretty double.

j- Cancri, separation i"-i, 5"-i, mags. 5-5, 6-5, 7-5 ; with
small telescopes the widtr component is readily seen.

V Draconis, separation 6i"7, mags. 4-6, 4-6 ; a pretty
and easy double, can be separated by observing with a
pair of opera glasses.

February, 1907.]

KNOWLEDGE & SCIENTIFIC NEWS.

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KHOWItEDGE & SCIEjillf IC JIEWS Off IGE,

27, CHANCERY LANE, LONDON, W.C.

February, 1907.]

KNOWLEDGE & SCIENTIFIC NEWS.

IX.

NOW REAPV.

THE SCIENCE YEAR BOOK

DIARY, DIRECTORY, BIOGRAPHY, & SCIENTIFIC SUMMARY

FOR t 307 .

cX?X CONTENTS. K^^

FRONTISPIECE.- Portrait of Lord Rayleigh.

ASTRONOMY.— The Calendar, Monthly Ephemeris, Tables for Latitude, Longitude, &c.,
Notes and Tables of Solar System, Paths of the Planets (with Charts), the
Moon, Eclipses, Comets, Jupiter's Satellites, the Stars, Maps of the Heavens, &c.

THE EARTH AND ITS INHABITANTS.— Notes and Charts on Geology, Magnetism,
Meteorology (Average Temperature, Rainfall, &c.). Geographical Exploration, Natural
History, Populations, Statistics, &c.

PHYSICAL AND CHEMICAL NOTES.-Air and Water, Light, Sound, Heat, Specific
Gra\ities, Spectra, Chemical Elements, &c.

METROLOGY.— Time, Trigonometrical Tables, Weights and Measures, Electrical Measure-
ments, Money, &c.

PROGRESS OF SCIENCE IN 1906.

DIRECTORY —Scientific Periodicals, Public Institutions, Universities and Staffs, Scientific and

Learned Societies, Prizes and Awards, &c.
BIOGRAPHIES of over jcxd of the Principal Workers in Science.
GLOSSARY of recently-introduced Scientific Terms.
DIARY.— One Page to each Day, Times of Sunrise and Sunset, High Water, Moon,

Meteorological Averages, Astronomical Events, &c.
Engagement Diary and Calendar, Letters received and despatched, Memoranda, Cash Accounts,
II^Q^^ Postal Information, &c., &c.

Nearly 600 Pages, La'ge Octavo, handsomely bound in Cloth, Gold Lettering, with

Changeable Monthly Calendar in Cover,

( POSTAGE:— Inland. 5d. Abroad, lid.

'( iinduding special packing.)

PRICE S/- NET.

^^ ABRIDGED EDITION,

consisting of the whole of the above contents, but without the Diary.
SAME BINDING, PRICE J3- NET.

POSTAGE :— Inland, 3d. Aho.iJ. 6d.
{including special facknig.)

SOME EXTRACTS FROM OPINIONS OF THE PRESS

ON THE 1906 ISSUE.

" Even- care appears to have been taken to make the volume serviceable to men of science and others
interested in natural knowledge. . . . The Year Book is thus a convenient and helpful companion for
the study, laboraton,-, or observatorj'." — Nature.

" A very excellent and thoroughly up-to-date annual." — English Mtchanic.

"The additions and improvements made in the current issue of this well-known scientiBc diarj- make
it, if possible, even more indispensable than ever to naturalists and scientific men.'' — Thi Naturalist.

" The whole production is unique, and its general get-up is beyond praise." — Electrical Rniew.

" Of the stream of year-bcoks .... \ery few— if indeed any — can surpass in point of use-
fulness and excellence of appearance the volume before us."— The Electrical Engineer.

" It is beautifully produced, on good paper, and full of information in all branches of scientific work,
especially astronomy. It is one of the best five shillings' worths in the market." — Electricity.

•• The whole is admirably arranged, .and the book should h.-ive the widest circulation, for it appeals to
the ordinary man as well as the student." — Alhcnaum.

" One book of reference that is really readable is the ' Science Year Book.' " — Daily Graphic.

" It contains an enormous amount of information in the way of statistics, and is altogether ven,-
cle\ er'y arranged." —The Sphere.

Pulblisliin^ Ofiice 27, Clia.ncer>y X^ane, X^ondon.

OR THROUGH ANY BOOKSELLER.

X.

KNOWLEDGE & SCIENTIFIC NEWS.

[February, 1907.

Wanted, fresh-water poly-

■' ZOA, &c., in (UMiuitN-, //.s.m'ci/
(\lin,li,l, during coinin'< season. — l.etkTS to
' Micro.," care of Knowlmick Olliie

FOR SALE.— Several tlionsands second-
liiiHl MICR05C0PE GLIDES by the Best
Mounters, 6/- do/cii. Itotany, Insects ;irul parts,
Anatomy, Kock sections, \c. Also SLIDE
CABINETS by Beck and olbers. hoUlini; from -•<«
to i,ooo sillies. MICROSCOPES— Swift Bacterio-
logical. Swmc-out Subst.iue, Abbe Condenser, Iris
Diaphragm, Triple Xosepiece, l| in., ,^in , ami A in.
Oil Imm. All as new, ^12. I'irst-class Beck Binn-
cular, with much Apparatus, (,m. 4 in. ASTRO.
TELESCOPE by the oni;,'fal Wrav. Finder, sever.d
Kyepieres, (:•,. Manv others, all kinds and maker-,.
Clarkson's Second Hand Optical Mart, 338, High
Holborn, London (.■|./i.i..i(f Uroii's Imi liil\.

fiN SALI-: —Astronom'cal Tele-

^^ scope liy \\ KA\, l{ in. char iiiH rtuie,
eradle support, trij-od. Under. f;l2. Anoihick. by
Solomons, 3^ in., mngnitlcently made tlirouKh-
out, two Btcidying ttle&copic rods to big ind, one
racking 8t.ndyit>g rod to eyepiece, plow nivt-on,
tripod, will respond to most ri»id test. .1'19.
Chemical Balance, Ah'ate bearings, just
overhauled by Or.UTLiNo, load 100. seof-it.ve
j\, milliLTninine, cost flfi, price A'6 10s. Zeiss'
Prismatic Binocular, slingcase, l"..
Chronometer by Akkold, IVi. Transit
Instrument by Tboitobton & Sim.ms, c.ivular
stand in ti'ass. adjusiirg screws, striding level,
1'6 lOj. Miner's Level, complete ;is m«. cost
.i'24, price i'7. Portable Microscope m
case, by Bi-:< k, IJ. Society of Arts Micro-
scope, compute in case, I'l 10s.
JOHN LACKLAND, :iO lilnekfriars Street, Salford,
-Manchester.

SECOND-HAND TELESCOPES

r)ia. Dallmeyer, Kquattnial, CNick, complete, £80.
4 ill. Cooke, Kqiuitoiiai ;in I Cloi I<. coiiiplei*'- £60.
."iiin. Cooke. .\li i/., i .iTitpirt..-. i,.;iil\ n.u, £17 lOs.

SECOND-HAND MICROSCOPES

Baker's Nelson No. 2, complete | «.„ _
with acces'^ories, > ^^'

Watson's Edmuurgh H Bac- ) «-- .-
teriologieat Outfit, ( **'* ^"^•

Swift's BacterioIof,McaI, best !

liattern, rnmpletp

£14 lOs.

STANDARD BAROMETER

by Paslorelli & kapktn. Perfect onler, £4 4s.
Many others, ali kinds. Nttv Lists on Application.

A. CLARKSON &. CO.,

28, Bartlett's Buildings, Holborn Circus, London.

3VIICROSCOI>Yr

H. W. H. DARLASTON,

20, FREtR ROAD, BIRCHFIELO, BIRMINGHAM-

Preparer of all kinds of Microscopical

Slides (Sample -jd.)

MEDIA AND ACCESSORIES FOR MOUNTING.

TUITION Br CORRESPONDENCE.

CIRCULATING SYSTEM OF SLIDES,

with great advantages to subscribers. Particulars
on application.

tm-S,, .l/ii-r.i. Jvii/.r, ,, „i,i„i.n. Jan. '07 issli.'.

MICRO. OBJECT MOUNTS.

Interesting Slide; VOLCANIC DUSTS, Vesu-
vit s 1900 and Soufiitre l*JU:i, on one slip, 1/4 post fixe.
9 Doubly btained BOTANICAL Sections. 6 IN-
SECT Dissectioi.s. 9 Varitti s of DIATOMS
(some test). 18 MISCELLANEOUS Objects.
Full iDstructioi s for mouutiag. Per Seri. s, 1/1 post
free. Samp e section and jjrice list. 2 stamps.
p^- See Mi ro. Editor's remarks, Jan., Uj6, Is»ue.

R. G. MASON, 69, CLAPHAM PARK ROAD, LONDON, S.W.

i.j ijcar-i' rt'i'iitatton fur ijtiu.ily.

LIVING SPECIMENS

FOB THB

MICROSCOPE:

Volvox globator, Desmids, Diatome, Spirogyra
Amoeba, Actinophrys, Spongilla, Vortioelia, btenior,
Hydra, Cordylopcbra, Stephanoceros, Melioerta,
Polyzoa, and other forms of fond Life, is. per tube,
with printed drawing, post free. Thomas Bolton,
Naturalist. 25. Ba*eall He>^th Roaci, Birminerham.

MICROSCOPIC SLIDES.

Choice Selected DIATOMS, mounted in Styrax.
Large variety British and Foreij^n Specimens. Lists

tree. Slides on approval.
"MICRO," 7, PARKEND STREET, BELFAST.

OF THE HEAVENS.

30 LAROE-SCALE STAR CHARTS,

CoverinR the whole star sphere. Catalo;;ues

of Double, Variable, and Coloured Stars. Nebula-, &c.

Full Atl«i Size 21/- Net.

THE CONSTELLMIONS AND HOW TO FIND THEM.

It I'l. It.--, .(I":

N. Ileinisplieie. 2/6; S. I liiiiiipheie, 3/6.

GALL A INOLIS, 23, Paternoster Square, London.

CHANCE: A Comparison of Facts
with the Theory of Probabilities. Hy

JoSKi'H Cohen (London: C. & E. Layloii.
pp..lS: price 2/. net). Author of " Monthly Ue:).i\-

iiirnl-;" and " I'rr-M'lil \'aliir Tabic?."

Second-hand Books at Half Prices!
New Books at 25,, Discount.

Bool<< in all hr>in hes of SCII:NCI; iiil
NATURAL MI.STORV and or All Hxaniina-
tions (i')lementary and Advaneed) snpp'ied Sent
on approval, fusts Pr' e. State Wi.nti. look.

bfuiclu. Good Prii-es L-ive '.
W. & G. FOYLE, 135, Charing Cross

Road, London, W.C.

I7'n,i in;/,/,/,'. I'lni'i (Iju'ifl St.)

TUITION BY
CORRESPONDENCE.

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Tuition in Latin, Greek, French, German, Itali.in,
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The staff includes graduates of O.\ford. Cambridge,
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.Wdress Mr. J. Charlfston, B.A., Burlington
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CORRESPONDENCE
TUITION.

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Every pupil treated individually. Splendid
places taken, mostly at first trial, by can-
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Full particulars on application to^

JOHN GIBSON, M.A.,

21. CHANCERY LANE, LONDON, W.C.

CLARKE

Specialists in

LEADENHALL STREET, LONDON

& PAGE,

Microscopy,

Students' Microscope (New Model).

4 Powers, Eyepieces, Polariscope, Spot Lens, Live

Box, Stage Forceps, &c., complete, £4 T 6.
MARINE S LI DES.—Zoophytes fully
expanded as in life, our own j/reparalion : beautiful
ntounts of Medusae, Mollusca, &c , Phyliip-
phoe with entire anatomy visible; Insect parts
without pressure.
Stcck of 20,000, all branches.
New Catalogue, also Second-hani List of Stands
and Accessories, Now Ready, free.

/-// '■,,'.. 71,

,(, liJl.

BOTANICAL MICROSCOPIC

SLIDES FOR STUDENTS,

Including Four Series, 50 Slides in each. Price
i'l Is. per series; illustrating Mitosis, Lcucoplasts.
Thyloses, Root, Stem, and Flower Development,
Anomalous Stems, Embryo-sac Structure, Pollen
Tubes, Algre, Fungi, Anthoceros, Pilixlaria, ^Iarsiiia
Iscetes, Selaginella, Finns, etc. Catalogue Post FrL-.-.
A. PENISTON, 5. MontpeUer Terrace. Leeds.

POPULAR MICROSCOPE SLIDES,

For ExHiutTioN or Stchv.
6d. eacli, 12 5 6, 25 10 6, 50 £1. LIST.

Ht: CTRRAnc; '•♦. Orchard Road,
. fc. tlJt5AUt, Kineston-on-Thames.

BADGER-HAIRS,

Clean, White-pointed, offereii by .JACOB
KORXEE, Manufacturer, H Hallefchestrasse,
Wahren, near Leipzig, Germany.

AND FINE PHOTOCRAPHS

tire clo.sely ulllcd. N'oii can jfet the be.st
neifutlvcs only hy huvinu: u len.s cupahle o(
Ifivinif keen definition at a liirite iiperliire.
In II Cooke iin.s you Ket both these qualities
in the hil,'llest decree, because it consists of
only lliree l li n t:lusses iincemented. which are
specially udju.sluble by us to obtain maximum
definition.

.S'l'jKt ,( p,),<tiV(rf/. <lii'ilin'i '/.im. far our jii'w haoklrt.

Taylor.. TAVLOi^t'lloDSOfJ L'»

> nunxi, LtiCCbTI

ToIeKramt :
"AUKS," LONDON.

Telsphona :
t8-i4 UKHBAIID.

ESTABLISHED 1760-

Stevens' Auction Rooms,

38, KING ST.,COVENT GARDEN, LONDON, W.G.

Every Friday at 12,30, Sales are held at the
Rooms of MioRoscopEB, Mhjuosoopio Slides, Telk-
scoi'Bs, Thkodolitrs, IjiiVELS, Elkctrical and
SoinNTiFJO Apparatuh, Cameras, and all kloda of
Photographio Apparatus, Lianterns, Ijantbrn
Slides, and all AooEasoRiEs in great variety, by
best) makers.

Natural History Sales onoe and twice a
month.

Curiosities, War Relics, Postage Stamps
once a month.

CalaUigufi and nil Particulan of 8aUi, Poit Free.

Valuations for Probate or Transfer, and Sales
conducted In any part of the Country.

To improve your Telescope, use

STEINHEIL'S

astronomical eyepieces.

In stock, at Steinheil's list prices.

Steinheil's Improved Hiiyshenian .. 10/- each,
do. Aciiromatic, of great

brilliancy 21/- ,,

do. Moiiocentric . . . . 21,'- ,,

STEINHEIL'S HIGHCLASS ASTRONOMICAL OBJECT

GLASSES AND TOURIST TtLESCOPES.

A. CLARKSON & Co.,

338, HIGH HOLBORN, LONDON.

(Oppo=.ite Gray's Inn Koad )

LIST OF FOSSILS.

JAMES R, GREGOHY & CO. have had
printed a List of about 1,000 of the more
common and characteristic British Fossils,
(representing abouc one-fift.h of their stock of
Fossils) . This List is very suitable for naming
and arranging collections. Post free, 3Jd.

Collections and Specimens of Fossils,
Minerals, and Rocks a Speciality.

JAMES R. GREGORV & CO.,

Mineralogists, &c.,

139, FULHAM ROAO, SOUTH KENSINGTON, LONOON, S.W-

SAVAGE CURIOSITIES.

Stock of over Sooo Speciineas of Weapons, Imple-
ments,Ornaments, Dress, Idols, Musical Instruments,
&c., &c., used by all the Races of Mankind, for sale at
very low prices. All objects guaranteed genuine. Tro-
phies of genuine old Arms made for Billiard Rooms,
Hails.&c.prices from 25s.; alsomounied Horns. -Cata-
logue of Ethnographical Specimens illustrated with
Bromide Photographs, 4'/. monthly, 3S.6rf. yearly. Col-
lections Arranged and catalotjued. Specimens bought.

W. 0. OLDMAN, 77, BRIXTON HILL, LONDON, S.W.
F. WIGGINS & SONS,

102 & 103, HINORIEB, LONDON, E.
Contractors to H.M.
Government.

LAMPS
STOVES
VENTILATORS
ELECTRICAL WORK

AND ALL I'CItrOSES

Largest Stock in the World. Tel No. 2248 Avenue

Feb., 1907.]

KNOWLEDGE & SCIENTIFIC NEWS.

SALE.

Season's Stoc k.
Unique Opportunity

8.000 LANTERN SLIDES.

Plain - 6d. each.
Coloured 1/- each.

BEST PHOTOGRAPHIC SLIDES,

COMPRISING ALL SUBJECTS.

Ghromatropes. Dissolving Sets.

AT ONE THIRD ORIGINAL PRICE.

OPTICAL LANTERNS.

Russian Iron & Mahogany Bodies.

SIX DOZEN LANTERN OBJECTIVES

^VARIOUS FOCI)

JETS, CONDENSERS, SLIDE CARRIERS,

OIL LAMPS. LIMES,
GAS CYLINDERS, FITTINGS OF ALL KINDS,

At one-third less than usual price.

Special Sale Friic List (htitis and I'ust /Vic an
request to : —

W. WATSON & SONS.

313, HIGH HOLBORN,

LONDON, W.C.

1^1^ 16, FORREST RD., EDINBURGH.
'- 2, EASY ROW, BIRMINGHAM.

ESTABLISHED 1837.

ICKARD

.^^^

TIME AND INSTANTANEOUS SHUTTER.

The First, the Best and Most Perfect.

Is now ''iipolied to order fitted with
NEW PATENT DISAPPEARING CORD.

In this improved device tlie cord runs back
into the shutter box after the blind iB set either
for focussing or exposure, thus entirely obviating
all risk of its becoming entangled.
Shut*er from 14;6. Disappearing Cord 3/G extra.

CATALOGUE POST FREE.
THE THORNTON-PICKARD MANUFACTURING

CO., LTD., ALTRINCHAM.

DENT'S CLOCKS,

WATCHES, AND CHRONOMETERS.

FOR SCIENTIFIC USE.

Sidereal or Mean Time Clocks for
Observatories, £21 and upwards.

E. DENT & CO., Ltd.,

WATCH, CLOCK & CHRONOMETER UAKERS

I'.y Specia.1 .\ppolntroent to H.M, the Kin^.
Makers of the Great West-
minster Clock, Bijf Ben.
Makers of the Standard
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the Principal Observatories
throughout the world.

o,,,;:^^.,- TRADE MARK

61, STRAND, and 4, ROYAL EXCHANGE, LONDON.

BEST
COCOAI

earthJ

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Special facilities for the printing and
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Also for the printing of Scientinc and Optical Instrument Catalogues.

IS£ Illustrations

in this %(fnXXinl

areb,|Vg0URNE&G

73. 1 UDGATE HiLL eg.

PHOTO-ENCRAVERS, ARTISTS,

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ASK FOR QUOTATIONS & SPECIMENS.

INSULATION TESTER,

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CHEAP ANO EFFICIENT.

Full I'lUlk-iiUir.^ <[!' aliorr, a/a.i

A New Form of Wheatstone Bridge and many other
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Are com. MM, ,1 in our ILLUSTRATED CATALOGUE OF ELECTRICAL

MEASURING INSTRUMENTS. "Iiich Mi.iy he had on applicalion.

ISENTHAIj & CO.,

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Coiitiactoys to the Admiralty, War. India, and Colonial Offices. >~,-.

Ask your GROCER for TO-DAY'S Leading Lines.

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RED,

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In making, use leBB quantity, H being much itronger than ordinary Coffee,

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EXCELSIOR SARDINES
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t

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WHOLESALE—

M. HENSOLDT & SONS, 38, holborn viaduct, London, e.c.

LARGE INDUCTION COILS.

FOR SPECTRUM ANALYSIS, WIRELESS TELEGRAPHY, AND
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The output from our Coils is exceptionally heavy, tlie dischsrpe being intensified
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fW SPECIAL TERMS TO SCIENTIFIC INSTITUTIONS.

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Contractors to many Departments of H.M. Govt.

Factory. Showrooms, and Offices:

la, ROSEBERY AVENUE, & 15-21, LAYSTALL ST., LONDON, E.C.

vr SUPPLEMENTARY LIST (covering all our latest inventions) free.

Printed and I'ublished for tlie I'ropvittois by Ki.ni^ Sell A' Olli.ni^, Ltd., 27, Chancery Lane, London, Vi'.C.—tebrunri/, 1907.