iTnts
A^^S^A^^^
SjA!&ftJSMMMM£MnES(?>^\(kftfrA^iAi9fib. & .<£^iaa\V9<SCI&..<&£&&. ^^SfidSP^^ XttiSSitS'^^'S&h^QSfM^^
D.JRA££lJUgES.
j^S^- ^ C£)
■SEVENTH EDITIONS
^'^'^-
,v^M
Advertisements.
S. W. SILVER & CO.,
SUN COURT, 67, CORN HILL, LONDON, E^.
ilOT-PKOOF CANVAS* TE^TI»». j EXPLORING
EXPEDITIONS
Completely Equipped
Br
S, W. SILVER & CO.,
INCLUDING THOSE OF
LORD RANDOLPH
CHURCHILL,
LORD DELAMERE,
MR. JOSEPH THOMSON,
-V MR. H. H. JOHNSTON,
_ _ Etc. Etc. Etc.
^ ^ ^ PORTABLE
— AiR-Tid-Sx-^ASEk CAMP FURNITURE
■ "Most of my things were ruined, except tho?e that were SJiiUiliilff atl<l
packed in the air-tight tin boxes supplied by your firm." X?«j#./;^ JT/m ; j./at-
Lady Brxssv.x, Sioibeam, R.Y.S. J>OtVie IVniie.s.
::^
FiLTKll Kkh>v n,u UsK.
S. W. SILVER & CO.'S NEW PATENT "EXPLORER'S" FILTER.
" The ebonite Pocket Filter wiih which you supplied me was of great value to me in
South Africa."— Henry Knollys, Lieut. -Col. Commauding Eoyal Art Uery in i-oiith Africa.
Patentees and Manu-
facturers of
"ANTI-RECOIL
HEEL PLATES,"
"SILVER SAFETY
BOLTS,"
RIFLES FOR LARGE
GAME.
TRUNKS,
BAGS,
List of Nkcessariks for rut; \
"EXPERT EJECTOR
REVOLVER,
"TRANSVAAL
RIFLE GUN,"
ETC.
Every Weapon requisite
for Hunters & Explorers.
Cnnvenient Range for
Te'-ting Arms.
PORTMANTEAUX OF
EVERY DESCRIPTION.
E !>• t\£Rv Part of thk Wmu.n "n
S. W. SILVER & CO.
a
Advertisements.
S.W. SILVER & CO.,
SUN COURT, 67, CORNHILL, LONDON, EX.
List of Articles manufactured by S. W. SILVER & CO.,
recommended for the use of Members of the Alpine Club.
RUCKSACKS.
No.] "Willosilcn" Canvas, size wluii tiat 'JN in. x •-« in., with 2 inside pockets.
N..! 3 ( anvas', liiicil with (heck Watci)ir(iipf .Material, -i iKickets outside, 10 in. x i; in.
S. W. S. & CO.'S
PATENT EBONITE WATER BOTTLE
Is Light, I>urahle,anil Heanly, and sijccially adajjtcd for the use
(if Travellers, E.xjilorers and Soldiers.
" It kecips anything cool on the hottest day."— Col. Pkkl.
Scots (iuarils.
"TUCKETT" SLEEPING BAG.
■■TUCKEW INSECT- PUZZLER.
"WHYMPER" TENTS.
" IC EC ^ I?. IC E E,"
and every arlicle of CJolhing for all Climatr/.
Folding Lanterns. Goggles. Alpine
Ropes. Ground Sheets.
FOOD AND FIRE COMBINED
sii.%j<:i< A. c«.'s M<:%v
FOOD
Moek Turtle Soup.
Mulligatawny .,
Ox Tail
Julienne
Vepetable
Soup and Bouilli.
Irish Stew.
Ctirried Rabbit.
Curried Fowl.
" ' Sl NBEAM,' K.Y.S.
" The ' Pic-Nic ' Soups have
l)ccn used on several oc-
casions, and we have found c- 1 d i-
them answer mostadiuirahly FIRE,
in every iiarticulav.
1.ADV Bn.issr.v."
KOrA BISCUITS
ROB-ROY CUISINES
WITH
Russian Spirit Lamps.
FOLDING CUPS,
COMPASSES,
DUCK PROVISION
BAGS,
BELTS, POUCHES.
'* One of the most in-
genious of modem contriv-
ances." — Sporting ondLramui ic
s. w.
KOLA CHOCOLATE.
SILVER & CO.
Advertisements,
PROTECTION FROM CHILL.
FIXED, MODERATE PRICES for FIRST QUALITY.
PURE WOOL
UNDERWEAR.
JAEGER
TRADE ON EACH
MARK GARMENT.
NO GOODS GENUINE
WITHOUT THIS TRADE MARK.
TESTED FOR PURITY,
Non-Shrinking
and
sassss^ Strength.
(THE BEST IS THE CHEAPEST.)
London Depots: 3 and 4, PRINCES STREET. CAVENDISH SQUAEE,
W., with Tailoring ; 126, REGENT STREET (near the Quadrant) ;
30, SLOANE STREET, S.W. (Kni°:htsbridse End) ; 456, STRAND
(close to Trafalgar Square); 158. FENCHURCH STREET (close to
Lime Street); 85 nnd S6,CHEAPSIDE (close to King Street); 42 and
43, FORE STREET (close to Moorgate Street Station), with Tailoring.
Dr. Jaeger's Health Culture, 188 pp., and Illustrated Jaeger Catalogue
supplied free.
Advertisements.
Telegraphic Address : Al> Iht <^CL SB. TELEPHONE No
"SAMOORE, LONDON.' 'v.^!?^^^2Sl«'^^ 3776.
SAVORY & MOORE,
Chcniiste to the (Sluccn an^
» . . 1b.1R.1b, tbe prince of Males,
Purveyors b)' Special Appointment to Her Majesty's Army,
Pesigkef^s and JVIanufactuf>ers of
Regulation Medical and Surgical Field Equipment
For Her Majesty's Army and Volunteer Services.
SPECIALLY DESIGNED
'' TRA VELLEB'S MEDTCIXi: BOX. ''
MEDICAL FIELD COMPANION CASE,
With all reqiiisite Medicines and Medical Appliances.
/'~^'C^ ATTMU T AA/rCTC Highly recommended on
(jLLAlllNn LAlVltLo, account of their great porta-
•"• bility and accurate dosage.
COMPRESSED MEDICINES.
MEAT PEPTONE AND OTHER CONDENSED PEPT0NI8ED FOODS -THE MOST
CONCENTRATED FORM OF ALIMENT.
143, NEW BOND STREET, LONDON, W.
HINTS TO TRAVELLERS
SCIENTIFIC AND GENERAL
EDITED FOR THE
Canncil of the llonnl (Bcogvaj-^hiral <S0ci£tj)
DOUGLAS W. FRESHFIELD, Hon. Sec. R.G.S.
AND
CAPTAIN W. J. L. WHARTON, R.N., F.R.S.,
Hydrographer to the Admiralty.
SEVENTH EDITION
BEVISEB AND ENLARGED
LON DON :
THE KOYAL GEOGRATHICAL SOCIETY,
1, SAVILE now, w.
AND AT ALL BOOKS!' LLERS'.
1893.
Price Eight Shillings ; to Felloics, at the Office of the Socitly. Fire ShiUiigs.
PRINTED BY WILLIAM CLOWES AND SONS, LIMITED,
STAMFORD STREET AND CHARING CROSS.
SECTIONS AND AUTHORS.
I. PRELIMINARY HINTS. By Douglas W. Freshfield, Hon. Sec.
Boyal Geographical Society ....... ]-7
II. HINTS ON OUTFIT, including Notes on Water Travel and
Mountain Travel. Compiled by Douglas W. Freshfield, icith
the aid of E. Whymper, J. Thomson, H. H. Johnston, J. Coles,
and others .......... 8-37
Orthography of Geographical Names 38-43
III. MEDICAL AND SURGICAL HINTS, By Surgeon-Major Tnos.
Heazle Parke, hon. d.c.l., hon. f.r.c.s.i., &c. . . . 44-82
IV. SURVEYING AND ASTRONOMICAL OBSERVATIONS. By John
Coles, f.r.a.s., Instructor to the Royal Geographical Society, in-
cluding Notes by Capt. Pratt, r.e., Lieut.-Col. H. H. Godwin-
Austen, F.R.S., Col. Sir C. W. Wilson, r.e., k.o.b., Francis
Galton, F.R.S., and Gen. J. T. Walker, c.b., f.r.s. . . . 83-320
V. PHOTOGRAPHY. By W. F. Donkin, m.a., f.c.s., late Lecturer in
Chemistry at St. George's Hospital. Revised and brought up to date
by J. Thomson, Instructor in Photography, R.G.s. . . . 321-331
VI. METEOROLOGY AND CLIMATE. By H. F. Blanford, f.rs.,
with notes by C. E. Peek, m.a., a Committee of the British
Associstiou, and R. H. Scott, F.R.S, ...... 332-379
VII. GEOLOGY. By VV. T. Blanford, f.r.s 380-393
Memorandum on Glacier Observations. Issued by the Committee
of the Alpine Club 394-396
VIIL NATURAL HISTORY. 5;/ H. W. Bates, f.r.s. Eeuised by ?. L.
Sclater, f.r.s. With Notes by G. E. Dobson, m.a., m.b., f.r.s..
Sir W. H. Flower, f.r.s., Osbert Salvin, f.r.s., Lieut.-Col.
H. H. Godwin-Austen, f.r.s., and J. Ball, f.k.s. . . . 397-418
IX. ANTHROPOLOGY. By E. B. Tylor, d.c.l., f.r.s., including Notes
by H. W. Franks, c.b., f.r.s., J. G. Frazer, H. H. Johnston,
and Francis Galton, f.r.s. 419-4.54
Paper Moulding of Monuments, or "Squeezes" By A. P.
Maudslay ......... 455-460
X. INDUSTRY AND COMMERCE. By J. S. Keltie, Assistant-
Secretary, Eoyal Geographical Society ..... 461—470
^2091178
CONTENTS.
SECTION 1.
PAGE
Preliuixary Hints (by Douglas W. Freshfielil, Hon. Sec. R.G.S.). , 1-7
SECTION II.
Hints on Outfit, including Notes on Water Travel and Mountain
Travel (compiled by Douglas W. Freshfield) .... 8-37
General Remarks, 8 — Methodical Arrangement, 9 — Security against
Breakage, Sec, 9 — Economy, 11 — Catalogue of Outfit, 11 — Pro-
visions, 11 — Clothing, 12 — Stationery, &c., 12 — Presents and
Ai'ticles of Barter, 13 — Camp Equipments, Tents, Cooking Stoves,
Filters, Tools, Arms, 13-15 — Some Requisites for a Tropical Tour,
16 — Some Requisites for a Tour in Cold Climates, 17 — List of
Mr. Whymper's South American Outfit, 17 — Tuckett " Insect
Puzzler," 23 — Mr. Mummery's Tent, 23 — Mr. J. Thomson's Notes,
23 — Mr. H. H. Johnston's Notes, 25 — Canoeing and Boating, by
J. Coles, 30-32— Mountain Travel, by D. W. Freshfield, 35.
Orthography of Geographical Names ...... 38-43
SECTION III.
Medical and Surgical Hints (by Surgeon-Major Thomas Heazle
Parke) 44-82
Personal Care of Health ........ 44-51
Head and Spine should be protected with great care, 45 — Avoid
Chills, Draughts, and Wettings, 46 — Use Mosquito Curtains, 47 —
Nocturnal Exposure to be avoided as much as possible, 48 —
Immersion in Cold Water to be avoided as much as possible in Hot
Climates, 48 — The Quantity of Food and of Drink should be care-
fully regulated, 49.
VI CONTENTS.
PAGE
Medical Diseases. ......... 51-65
Cold in the Head, 51 — Bronchitis, 52 — Pneumonia, 52 — Pleurisy, 53
— Rheumatism, 53 — Colic, 54 — Constipation, 54 — Dysentery, 54 —
Fever, 55 — Allections of the Liver : Congestion, Abscess, 57 —
Night Blindness ; Snow Blindness, 57 — Ophthalmia, 58 — Piles, 59
— Prickly-heat, GO — Ring-worm, 60— Sea-sickness, 60— Sleepless-
ness, 61 — Sunstroke, 61 — Parasites, 62— Care of Infants and
Children, 62.
Surgical Diseases and Injuries . 65-76
Bleeding (Ha}morrhage), 65 — Blisters on the Feet : Boils and Car-
buncles, 67— Bruises, 67 — Burns, 68— Chilblains and Frost-bites,
68 — Concussion of the Brain, 68 — Drowning, 69 — Fractures; Dis-
locations, 70 — Parasites, 73 — Rupture, 73 — Snake-bite, 74 —
Sprains, 75— Ulcers, 75— Wounds, 76.
Rules for the Preservation of Health in the Tropics . . 76-77
List of Useful Articles ........ 77-80
Transport 80-82
SECTION IV.
Surveying and Astronomical Observations (by John Coles, F.R.A.S.,
and others) • 83-320
Part 1. — Instruments used in Surveyinij ...... 83-132
Preliminary Remarks, 83 — Scientific Outfit, 84 — Examination of
Instruments, 90 — Packing, 91 — Instruments and their Adjustments :
Prismatic Compass, 92 — Pocket Compass, 93 — Observations with
the Prismatic Compass, 93 — Hypsometrical Apparatus, 94 — To use
the Boiling-point Thermometer, 95 — Aneroid, 96 — Boylean-Mariotti
Barometer, 97 — George's Mercurial Barometer, 99 — Sextant, 100 —
Adjustments of the Sextant, 102 — Index Error, 103 — Box or Pocket
Sextant, 105— Artificial Horizon, 107— Sextant Stand, 108— Transit
Theodolite, 108 — Adjustments of the Theodolite, 111 — Everest
Theodolite, 118 — Adjustments of Everest Theodolite (by Captain
Pratt, R.E.), 118— Tacheometer, 120— Plane Table, 124— Plane
Tables used in the Indian Survey Department, 126 — Form for Field
Book for Plane Table Surveying, 129 — Watches, 130.
CONTENTS. Vll
PACK
Part 2. — Plane Trigonometry and Preliminary Remarks . , . 133-151
Plane Trigonometry, 133 — Extemporary Measurements : To set oft' a
Right Angle from any point on the Ground by means of a Rope,
139_To find the Meridian by a Watch, 139— To find the Meridian
by the Sun without Instruments, 139 — To find Distance of Inacces-
sible Object with a Measuring Line, 140 — Rough Methods of
Measuring, 141 — Distance by Sound, 142 — Table of Rough Triangu-
lation (by F. Galton, F.R.S.), 143 — Ascertaining Heights by Angles
of Elevation, 145 — Flashing Signals, 146 — Measurement of the
Number of Cubic Feet of Water conveyed by a River in each
second, 146 — Map Projections, 148.
Part 3. — Surveying 152-187B
Mapping a Country, 152 — Route Survey with Prismatic Compass,
Boiling-Point Thermometer and Aneroid, 153 — To Plot the
Bearings, 155 — Hints on Use of Sextant in Surveying : To measure
the Angular Distance between two objects, 159 — Table for as-
certaining Heights and Distances by the Sextant, 160 — Surveys
with Sextant and Prismatic Compass : Projection, Scale, 163 —
Route Survey, 164 — District Survey, 164 — Special Survey of a
small Tract of Country, 171 — Survey of Plot of Ground containing
Ruins, &c., 172 — Surveying with the Plane Table : Orienting the
Table, 175— Broken Survey, 180 — Concluding Remarks, 181 —
Lieut. -Col. Godwin-Austen's Remarks on Plane Table, 181 — Sur-
veying with theTacheometer, 185 — Surveying a Country and Fixing
Positions by means of Latitudes and Azimuths, 187a.
Part 4. — Astronomical Observations ...... 188-311
Necessity for Astronomical Observations, 188 — Sextant Observations,
Telescope Observations, 189 — Observations of Heavenly Bodies with
the Sextant, 190 — Observations for Latitude : — Latitude by Meridian
Altitude of Sun, 191 — To Find Time of Meridian Passage of Star,
192— Latitude by Meridian Altitude of a Star, 193 — Circum-
meridian Observations, or Observations near the Meridian, 194 —
Latitude by Altitudes of a Star or Planet, near the Meridian, 195 —
Latitude by Double Altitudes of Sun, 197a— Time, I'd^— Observa-
tions for Finding Time and Longitude : — To Find Error of Watch by
Absolute Altitudes, 200 — Longitude by Chronometer, from Alti-
tudes of the Sun, 202 — Longitude by Chronometer, from Altitudes
VUl CONTENTS.
of ;i Star, 204— Kciual Allituaes of Sun, Star or Planet, 206—
To Kind Error of Watch by Equal Altitudes of tho Sun, 208— To
Find Error of Watch by Equal Altitudes of a Star, 210 — Equal
Altitudes of a Star on the same side of the Meridian, 210 — Kate,
2'11 — Longitude by Meridian Distance, 212 — Longitude by the
Occultation of a Star, 213 — Lunar Observations, 218 — Longitude
by Lunar Distance, 223 — To Compute the Altitude of a Heavenly
Body, 225 — Computation of Moon's True Central Altitude, 227 —
Longitude by Moon Culminating Stars, 229 — Longitude by Eclipses
of Jupiter's Satellites, 235 — Observations for Bearings: To Find
True lieariiig of a Peak or any other Object by means of its Ob-
served Angular Distance from the Sun, 236 — Finding the Error of
the Compass by the Sun's Azinnith, 239 — On Observations with
Theodolites or Altazimuth Instruments (by Gen. J. T. \Valker,
R.E.), 240— Explanation of the Tables, 256— 7'a6/fS, 261.
Determination of Heights (by F. Galton, F.n.s.) .... 312-320
By the Temperature of Boiling Water, 312 — By Barometer or
Aneroid, 317.
SECTION V.
PHOTOGRAruY (by W. F Doukiu, 31. A., revised by J. Thomson) . . 321-331
General Remarks, 321— Camera, 322— Hand Cameras, 323— Focussing
Cloth, 324 -Camera Stand, 324— Small Circular Level, 324 —
Lenses, 324 — Focus, 326 — Exposure Tables, 326 — How to keep
Plates and Films dry, 327 — Apparatus and Chemicals for Develop-
ment, 328— Taking a Picture, 329— Exposure, 330 — Cost of Photo-
graphic Outfit, 331.
SECTION VI.
Meteorology and Climate (by H. F. Blanford, F.R.S., and others) . 332-379
General Remarks, 332 — Instruments and Outfit, 333 — Barometric
Observations, 338 — Oscillations of the Barometer, 340 — Temperature
Observations, 340 — Most important Elements of Climate in respect
of Temperature, 342 — Humidity Observations, 343 — Rain, Snow,
Hail, Dew, &c., 345 — Winds, 347 — State of'the Sky and Atmosphere,
Cloud, &c., 349— Storms, 351— Special Observations, 353— Table
showing the Pressure of Aqueous Vapour in Inches of Mercury at
Lat. 45° for each degree Fahr. from -30° to 119° 357— In-
CONTENTS.
IX
structions issued by K. Meteorological Society (note by. C. E. Peek),
358 — Table of Relative Humidity, 362 — Hints to Meteorological
Observers "in Tropical Africa, by a Committee of the British Asso-
ciation, 368 — Note by Robert H. Scott, f.r.s., 376 — List of Meteoro-
logical Stations and Observations, 1893, 377.
SECTION VII.
Geology (by W. T. Blanford, F.u.s.) .......
General Remarks, 380 — Outfit, 381 — Collections, 382 — Mountain
Chains, 387 — Volcanoes and Volcanic Rocks, 388 — Coasts, 388 —
Rivers and River Plains, 389 — Lakes, 389 — Evidence of Glacial
Action, 390 — Deserts, 391 — Early History of Man in Tropical
Climates, 392 — Permanence of Ocean Basins, 392 — Atolls or Coral
Islands, 393.
Memorandum on Glacieu Observations (issued by the Committee of
the Alpine Club) .........
SECTION VIII.
Natural History (by W. H. Bates, f.r.s., and others. Revised by P. L.
Sclater, F.R.S.) .........
Outfit, 397 — Where and what to Collect, 399 — Mammals and Birds,
401 — Preserving Mammals, &c., in Alcohol, 404 — Preparation ot
Skeletons of Animals (by Sir W. H. Flower, F.R.S.), 406 — Reptiles
and Fishes (by Osbert Salvin, F.R.S.), 407 — Laud and Freshwater
Mollusca (by Lieut. -Col. H. II. Godwin-Austen), 409 — Insects, 410
—Botanical Collecting (by J. Ball, F.R.S.), 412— Fo.ssils, 416—
General Remarks, 417 — Observations of Habits, &c., 417.
SECTION IX.
380-393
394-396
397-418
419-454
Anthropology (by E. B. Tylor, d.c.l., and others) ....
General Remarks, 419 — Physical Characters, 419 — Language, 423 —
Arts and Sciences, 426 — Society, 431 — Religion and Mythology,
437 — Customs, 439 — Queries on Anthropology (by A. W. Franks,
C.B., F.R.S,), 440— Ethnological Questions (by J. G. Frazer), 443 —
Hints on Anthropology (by H. H. Johnston), 445 — Statistics of
Strength, Stature, &c. (by F. Galton, F.R.S.), 448 — Note on Finger
Prints (by F. Galton, f.r.s.), 454.
Paper Mouldings of Monuments or "Squeezes" (by A. P. Maudslay) 455-460
CONTENTS.
SECTION X.
PAGE
Industry and Commerce (by J. S. Koltie, Assist. Sec. R.G.S.) . . 461-470
General Remarks, 461 — Minerals and Metals, 463 — Vegetable Pro-
ducts : — Character of Surface, 464 — Forests, 464 — Timber, 464 —
Fibres, Fruits, Chemicals, &c., 464 — Other Vegetation, 465 —
Marshes, Deserts, Irrigation, 465 — Agriculture, 466 — Animal Pro-
ducts : — Domestic Animals, 467 — Fisheries, 467 — Trade, 468 —
Climate, 468 — Facilities and Hindrances to Commercial Develop-
ment : — Water Communication, 469 — Roads, 469 — Railway Routes,
469— Labour, 469— Currency, Tarifls, &c., 470— Inhabitants, 470.
LIST OF ILLUSTPvATIONS AND MAPS.
The Tuckett " Insect-Puzzler " .
Spectacles for Preventing Snow-Blindness .....
Extemporary Splints, for Setting Broken Limb ....
Prismatic Compass .........
Pocket Compass .........
Hypsometrical Apparatus . . .
George's Mercurial Barometer .......
The Sextant ..........
Box or Pocket Sextant ........
Transit Theodolite .........
Diagram Illustrating Method of Adjusting Vertical and Horizontal wires
of Telescope of Theodolite .......
Diagrams showing Appearance of Sun's Upper and Lower Limbs in Tele
scope of Theodolite ........
Transit Theodolite with Level Carried on Vernier Arm ...
Everest Theodolite .........
Tacheometer ..........
Diagram Illustrating Method of Measuring Distances with Tacheometer
Staff to be used in Measuring Distances with Tacheometer
The Plane Table
The Indian Plane Table
Specimen of Portion of Plane Table Work .....
Diagrams Illustrating Pi-oblems in Plane Trigonometry, and Findin
Heights and Distances .......
Diagram showing Method of Setting-off a Right Angle by means of
Rope ..........
Diagram Illustrating Method of Finding the Meridian by the Sun, withou
Instruments ...... . .
Diagram Illustrating Method of Finding Distance of an Inaccessible Objec
with a Measuring Line .......
Diagram accompanying Table of Rough Triangulatiou .
Diagram Illustrating Principle of Conical Projection
PAGE
22
58
70
92
93
95
98
101
105
109
111
115
116
119
121
122
123
125
127
128
133-138
139
140
141
144
151
Xll
LIST OF ILLUSTRATIONS AND MAPS.
Map Illustrating Ruute Surveying with Prismatic Compass, Boiling-Foint
Thermoinoter, &c. ........
Chart of the WorUl, showing Lines of Equal Magnetic Variation, 1893
Diagrams Illustrating Method of Measuring Horizontal Angles betwee
Terrcstial Objects, with a Se.xtant .....
Diagrams Illustrating Col. Sir Chas. Wilson's Article on Surveys witl
Sextant and Prismatic Compass (Principle of Survey, Trigonometrical
Problems, &c.). .....
Diagram showing Principle of Plane Table Survey
Diagrams Illustrating Methods of Orienting and Fixing Position on Plane
Table
Map to Illustrate Method of Surveying a Country and Fixing Positions b
Means of Latitude and Azimuths
Diagram sliowing that Errors, caused through Faulty Method of Makins
the Contact in Lunar Observations, are not Eliminated by Taking Dis
tauces East and West of the Moon
Bellows Camera .....
Koss Rapid Symmetrical Photographic Lens
Zeiss Photographic Lens
Screen for Hanging Thermometers
Meteorological Charts, showing Isothermal and Isobar
with Prevailing Winds for January and July
Screen or Thatched Shelter for Meteorological Instruments
Vernier of Fortin's Barometer .....
General Collecting Case (Natural History) .
Drying Presses for Botanical Specimens
Illustrations of Paper Moulding Process, or " Squeezes "
Star Maps : The Northern Constellations.
The Southern Constellations.
ric Lines,
(4 charts.)
gethe
158
158
1(31
165-171
174
170-178
187a
'J19
322
325
325
336
356
370
372
404
413-414
456-458
PKEFACE TO SIXTH EDITION.
In issuing to the Fellows of the Eoyal Geographical Society and the
public the sixth edition of Hints to Travellers it seems desirable to give
a brief historical sketch of the various changes the work has gone
through before it reached its present form.
As long ago as 1854 the Council of the Society, in consequenco of the
frequent questions addressed to them by intending travellers, requested
the late Admiral Fitzroy and Lieutenant Eaper, K.N., to consider what
instrumental outfit might best be recommended to explorers. Their
report, together with suggestions submitted to them by Admirals Smyth
and Beechey, Colonel Sykes and Mr. Francis Gal ton, was printed in
vol. xxiv. of the Journal of the Society, and separately circulated in
pamphlet form under the title of ' Hints to Travellers.'
The exhaustion of this first edition led, in 1864, to the revision and
enlargement of the original work by a Committee of Council, consisting
of Sir George Back, Admiral Collinson and Mr. Francis Galton. Their
'Hints' were prefaced by the remark that they were addressed to a
person who, proposing to explore a wild country, asks what astronomical
and other scientific outfit he ought to take with him, and what observa-
tions he may attempt with a prospect of obtaining accurate results.
Hints on Photography by Dr. Pole, and on the Collection of Objects in
Natural History by Mr. Bates, were added.
XIV PREFACE.
Tho success of this volume resulted in the publication, in 1871, of a
third edition under the same editorship. This edition was followed in
1878 by tlie fourth, published under the sole editorship of Mr. F. Galton,
and in a now form more convenient for pocket use.
In preparing the fifth edition the Council, anxious to increase the
usefulness of the volume, and to make it meet the, in some ways, higher
requirements of a new generation of young travellers, many of whom had
received scientific instruction in the Society's office before leaving
England, appointed an Editorial Sub-Committee, consisting of Colonel
H. H. Godwm Austen, Mr. J. K. Laughton, and Mr. Douglas W.
Freshfield, to remodel the * Hints.'
The first object of those charged with the direction of this edition
was to furnish such help as might be possible within the compass of a
convenient pocket-book to the intelligent explorer who, in the hope of
obtaining from his travels valuable geographical results, has been at
some pains to acquaint himself with the use of instruments. The Hints
on Surveying, the principal portion of the work, were placed in the
hands of Mr. Coles, late E.N., the Society's Map-Curator and Instructor
in Practical Astronomy and Surveying.
The Hints on Collections in Natural History were expanded, and
Hints on how and what to observe in other sciences. Geology and
Anthropology, added by Mr. W. T. Blanford and Mr. E. B. Tylor
respectively. The section on Photography was re-written by Mr. W. F.
Donkin, who had, in the High Alps, had exceptional experience in taking
photographs under circumstances of great difficulty, both as to transport
and exposure. Since the success of every journey depends primarily on
the health and suitable equipment of the members of the expedition, the
Editors decided further to enlarge the scope of the work by supplying
Hints on Medical Treatment and Precautions, and on General Outfit.
The former, drawn up by Surgeon-Major Dobson, have been found of
great value.
PREFACE. XV
This fifth edition is now exhausted. The changes and additions made
in it having met with general approval, the present Editors have not
attempted to make any material alteration in the character of the book.
It has received at their hands such correction as time and the progress of
science and discovery render needful, and such additions as experience
suggests may be of use. The various sections have been revised, and
enlarged in most cases, by their authors. The hints on Meteorology have
been re-written by Mr. H. F. Blanford. Captain Abney has brought up
to date the late Mr. W. F. Donkin's notes on Photography, and Mr.
J. S. Keltic has supplied new hints on Commercial Geography. An
index has been added.
In a work of this character omissions must of necessity be discovered.
In order to reduce their number and importance as far as possible, it has
throughout been the aim of the Editors not only to intrust each chapter
to a competent hand, but also to provide for its being read and revised
before publication by high independent authorities in the same branch of
knowledge. This course could not have been carried out without the
cordial assent and co-operation of their responsible contributors, to
whom, as well as to the many gentlemen who have given the benefit of
their advice, the Council desire to return their grateful acknowledgTuents.
Any corrections or additions which may suggest themselves to readers
should be communicated to the Secretary of the Society, 1, Savile Eow, W.,
for the use of the Editors of the next Edition.
Douglas W. Freshfield.
June, 1889. W. J. L. Wharton.
PREFACE TO SEVENTH EDITION.
In the present edition )m]iortant additions and corrections have been
made, hut no material alteration has been made in the general
arrangement. The various sections have been revised and brought
up to date, and the Medical Hints have been re-written.
Douglas W. Feeshfield.
W. J. Ij. Wharton.
HINTS TO TEAVELLEES.
I.
PEELIMINAEY HINTS.
By Douglas W. Freshfield, Hon. Sec. E.G.S.,
President of the Alpine Club.
This work will come into the hands of very different readers. In the
first place it will undergo the criticism of the small body of what may be
called " professional " travellers, men trained in at least the elements of
surveying, practised in general observation, and experienced in the shifts
of travel. By them, it is hoped, it may be accepted as a handy, and at
times a suggestive j^ocket-book. But travellers such as these now form
only a small proportion of the Englishmen and Englishwomen who,
on biisiness or pleasui-e, yearly extend their wanderings over the globe.
One of the results of the rapid multiplication of lines of ocean steamers
and of railways in distant seas and far-off countries has been to make it
easy for men of comparatively brief leisure to undertake a share in
exijloration in the coiu'se of a vacation tour. The goal of ten years ago
has become a starting-point; Merv has a railway station and several
inns ; excursion steamers run — or will shortly run — to Alaska and Mount
St. Elias. India has become commonplace, and Members of Parlia-
ment spend their holidays in Siberia, Brazil, Korea, or the Antipodes.
The vacation travellers, or tourists, who are tempted by modern facilities
into imperfectly-known regions are numerous, and their opportunities
for collecting valuable information arc great, while their power of
profiting by them is as a rule far from commensurate.
The children's story of "Eyes and Ko Eyes" is constantly being
exemplified in the recent literature of travel. It would be extravagant
indeed to expect all travellers to take up scientific sm-veyor's work^
B
2 HINTS TO TRAVELLERS.
however desirable it may be to increase the number of those who flo so.
Again, few Englishmen would liave the patience to emulate the native
Indian surveyor who measures the distances traversed over many
hundred miles by ceaselessly counting his own paces. But topography
and g6odcsy are but a part, even if tlic foundation, of modern geography.
It is a loss, both to himself and to others, when a traveller does not
observe, or fails to take notes of, the objects and the people he meets
with ; when he brings back no fresh facts as to topography, natural
history, climate, customs, and antiquities; when he uses neither the
pencil nor the camera to record the scenery, the buildings, or the people
he has met with in his journey. The aim of this volume is to assist all
travellers to make their travels more pleasant to themselves and more
profitable to others by increasing at once their interests and their means
of observation. Non omnia possumus omnes ! Each will take, doubtless,
his own special line. Yet it may be well to point out that there is no
one more in need of warning and advice than the specialist or
"scientist" who confines himself to one branch of knowledge. He is
apt not ouly to miss opportunities in other branches, but he frequently
impairs the soundness of his observations in his own subject by failing
to take into account, accurately and intelligently, natural agencies or
phenomena which interact with those that he especially studies. There
is yet another class for whom this work is intended, those residents
abroad whom duty compels to spend large portions of their lives in
remote localities, and who have, therefore, the best opportunities for
collecting and presenting complete and accurate information concerning
distant regions. These ' Hints ' have been discovered by Lieutenant
Youughusband in the hands of a Eussian Consul-General in Central
Asia! Certain additions, with a particular view to the advantage of
such far-oflf residents, have been made to the Medical Hints, the value of
which has been borne witness to by many of the travellers who have
used recent editions of this work.
The traveller, as soon as he has resolved where he means to go, should
read the best books on the country, and decide which, if any, it is worth
his while to take with him, and make extracts for his own use from
others. Still more important is it for him to study the best majDS, and
with these it is indispensable that he should jjrovide himself, mounted
for use ; a map that cannot be kept in the pocket is of little service. If
PEELIMINARY HINTS. 6
he is residing in England, the traveller will find the needful books and
maps at the Eoyal Geographical Society, the officials of which will give
him any information in their power, and put him in communication with
those who can give more. Pie will do well also to consider the question
of language, and, if possible, to learn something beforehand of any that is
likely to be specially useful to him ; at any rate, to provide himself with
a dictionary and phrase-book, where such exist. If he is no draughts-
man — indeed in any case — he can, and ought to, take some lessons in
photography, which, though an art in the hands of only a few, is a
tool of the utmost value in most branches of discovery for the many.
Such lessons can be procured through the Eoyal Geographical Scciety's
Scientific Instructor. The Society's Secretary, Mr. Keltie, is also in-
structed to arrange lectures in botany and geology for intending
travellers.*
The would-be explorer should, by all means, after a sufficient reference
to the best sources of information, form a detailed scheme of what he
intends, or rather hopes, to do. How far this scheme should be adhered
to is a question to be governed by circumstances and personal advice.
Local advice should be given its due weight, taking into account the
individual character, and official or other particular bias of the informant,
and also bearing in mind, on the one hand, that where danger from
inhabitants is concerned, the conditions of travel are apt to vary from
year to year, and that the latest news is generally the surest ; on the
* The following is the advertisement issued by the Society witli regard to the
terms of these lessons (1889).
Arrangements have been made for the instruction of intending travellers in
the following subjects : —
1. Surveying and Mapping, including the fixing of positions by Astronomical
observations. By Mr. John Coles, Map Curator of the Society.
2. Geology, including practical training in the field. By Mr. W. Topley, of
the Geological Sui-vey ; President of the Geologists' Association.
3. Botany. Applications should be made to the Director, Eoyal Gardens, Kew.
4. Photography. By Mr. John Thomson, Author of ' Photographic Illustra-
tions of China and its People,' and other works.
The lessons are given on days and at hours arranged between the Instructor
and the pupil. The fee to pupils is, for each lesson of an hour, 2s. 6d. Tickets
for the lessons must be previously procured at the Offices of the Society.
B 2
4 HINTS TO TRAVELLERS.
other, that residents are apt to over-estimate obstacles they have never
themselves faced. The unknown, in mountains and elsewhere, is often
the impossible even for educated Englishmen — much more is it so for the
native inhabitants.
In the selection of his field the professional traveller who seeks wholly
new ground need, as yet, be at no loss for choice, even outside the Arctic
and Antarctic regions. The interior of New Guinea is still almost
virgin to Europeans ; several of the East Indian Islands, particularly
liorneo and Formosa, large portions of Tibet, and the native states
on the northern frontier of India and Upper Burmah, present many
purely topographical problems. Africa is still very far from being ex-
hausted, if the mysteries to be solved in it are gradually being narrowed.
South and Central America seem at last to attract their fair share of
enterprise ; and the ranges on the Pacific coast of North America are,
from the scale of their glacial phenomena, certain soon to be studied
in detail. But the old conception of geography which looked on it as
pure topography, as equivalent to surveying and map-construction, is
fast dying out, and travellers, as well as geographers, are becoming
familiar with the idea that their business is to furnish a picture of the
earth's surface as it is, and in relation to its inhabitants. To this
knowledge, as set forth in such a work as M. Eeclus's 'Geographic
Universelle,' an acquaintance with the topography of a countiy is only
a preliminary. It may seem a paradox, yet it is true, that there is
hardly a country in Europe the materials for the geography of which
are complete. In England itself, to give a single instance, we do not
yet know the depths of our inland waters. Large tracts of the Alps
and the Pyrenees were within the last twenty-five years, mapped for
the first time with any approach to accuracy by private and individual
energy. The Balkan Peninsula is far from being exactly described. A
little further afield in Morocco, Asia Minor, the Western Caucasus, Syria
east of the Jordan, in the easily-accessible western portions of Northern
America— in short, in regions within a fortnight of London, there is still
room for any number of intelligent observers.
Next to the choice of the field for travel comes another primary
matter on which hints are hardly likely, perhaps, to be serA-iccable, yet,
which is the most important of all — the choice of a companion. Those
who have never travelled at all together will always, before entering ou
PRELIMINARY HINTS. 5
any prolonged partnership, bo wise to test their sympathy or powers of
mutual accommodation, in some short excursion. Of course diversity
of studies -will lead to greater richness in results. A first-rate photo-
grapher — a first-rate specialist of any kind — is apt to get absorbed in
his work ; it is everything that his companion should be industrious
with his note-book, and handy in camp. A botanist, or an entomologist,
is very apt to see nothing more than a few yards distant ; a mountaineer
to overlook any feature less than two miles high! Where tastes are
diverse each will learn from his companion, and the common result will
be enriched.
A few commonplaces, drawn chiefly from the writer's own limited
experience, may perhaps be added usefully here. In all dealings with
camp-servants and natives be first of all patient, nest just and firm,
dealing praise and blame alike sparingly, but heartily. Never lose
your temper — except on purpose, and avoid banter. When you have
to communicate through an interpreter, endeavour to be present yourself
at all important discussions. Arrange for your transport for as long
periods as convenient, and pay whenever possible by distance, and not by
time, if you want to get on. Do not let your visit be an expense, but
rather a source of profit, in some way or other, to your hosts. The
present you intend to give on leaving may be judiciously shown and
hinted at beforehand; it will increase the attention paid you, and be
more effective than if kept in reserve as a surprise.
Make it a rule to start as early in the day as possible. In many
climates clouds obscure the view, or the heat is intolerable in the
afternoon. And it is an advantage when camping to have plenty of
daylight after arrival.
Eemember that the first and best instruments are the traveller's own
eyes. Use them constantly, and record your observations on the spot,
keeping for the purpose a note-book with numbered pages and a map
(where the latter is procurable) always at hand in a buttoned pocket.
The more little rough sketches, outlines, sketch-maps you introduce into
your note-book the better. Put down, as they occur, all important
objects ; streams, their volume, colour ; mountain ranges, their character
and apparent structure and glaciation, the colour and forms of the land-
scape, prevalent winds, climate. Note all chcmgca in the physical aspect
of the country, soil, rocks, vegetation, flora, and fauna; the limits of
G HINTS TO TRAVELLERS.
tribes, their dwellings, places of worship, tombs, and particularly ancient
cemeteries, domestic furniture, customs, antiquities, &c. In short,
describe to yourself at the time all you see and learn in your diary.
I have puriDosely limited myself here to the most elementary sugges-
tions. I do not, of course, assume that any traveller will be without at
least a good watch, a compass, a thermometer, and an aneroid (an in-
strument ■which, carefully ivorn like a watch, from the commencement of
the joiirney, I have found more satisfactory than have most travellers,
and in which further improvements may be looked for). But I must not
trespass here on the province of the Scientific Instructor. Readers will
find all necessary information in the important section of this work which
Mr. Coles, under the supervision of my co-editor. Captain Wharton, k.n.,
the Hydrographer to the Admiralty, and with the assistance of several
distinguished survey officers, has very carefully revised.
General instructions as to linguistic collections will be found among
the Hints on Anthropology. The traveller's business is to try and get
a native name for everything he sees. But to ascertain correctly the
native names for natiiral features, and even for villages, is often a very
troublesome task, and the most grotesque blunders may easily be made.
Pronunciation in a partially-understood tongue or dialect is imperfectly
heard, and a little knowledge leads astray. Names are frequently given
to districts rather than to individual hamlets. Streams are differently
named in different parts of their course.
But it is with mountain ranges, and, above all, with individual summits,
that the greatest difficulties arise. A summit, unless exceptionally con-
spicuous, has frequently no name apart from the chain or block to which
it belongs, or the i^ass nearest it. A chain or block will get a name from
the pasturage on its slope ; or it will be called after the valley at its
base ; or, more frequently, from the valley on the other side reached by
crossing it. In the latter case, it is obvious that it will probably have
two names. As a rule a name given to a massif , or group, should be
applied to its highest point. For that it is vertical, and not lateral,
extension that differentiates mountains, that their essential feature is
their height, and that their individuality resides in their highest point,
are very modern refinements.
Whatever further hints my experience suggests may best be included
in the chapters that follow. I will here only add a few words as to
PRELIMINAKY HINTS. 7
the method and form to be adopted by the traveller in preparing the
permanent record of his journey after its completion.
The traveller, immediately on his return, should write out from his
notes a full diary. This done, let him lay it aside for a short time, and
read afresh all he can find on his subject. He "will then be ready to
take up again his own manuscript, and, if he sees his way to make an
interesting paper or volume, to come to the important decision whether
he shall retain the narrative form, or arrange his material otherwise.
Should he retain the narrative form — and it has many advantages — let
him erase repetitions ; enlarge on, or mass together, typical and instruc-
tive experiences ; insert, where most convenient, condensed summaries
of the results of his observations on special subjects, showing how and
where they modify, or enlarge, the conclusions of his predecessors. The
lecturer or author who furnishes a bare record of how he got over the
groimd, without iDausiug to give any definite picture of what he has seen
and learnt, is the terror of geographical meetings, and his book is
destined to comparative failure. His observations may serve as a basis
for maps ; he may have earned credit as an exact topographer ; but as a
geographer, in the higher sense of the word, he will have failed.
Statistics, and details of topography and distances, most valuable in the
study, should, as a rule, be omitted in reading a paper before a general
audience, which requires definite pictures sufficiently filled in to be
apprehended and remembered. If the traveller has to give many figures,
or much technical information not necessary to the general reader, let
him employ an appendix or footnotes. Finally let him attend himself to
his maps and illustrations, and not forget a good index.
( » )
II.
HiNTS ON OUTHT.
INCLUDING NOTES ON WATEK TEAYEL AND MOUNTAIN TRAVEL.
Compiled hy DoUGLAS W. Fbeshfield, roith the aid of E. Whymper,
J. Thomson, H. H. Johnston, J. Coles, and ofhers.
Suggestions regarding a suitable outfit for a traveller must necessarily
be of the most general character, as each traveller requires a special outfit
according to the nature of his journey, its aims and duration, the numl>er
of iiersons composing the expedition, and the funds at command. An
outfit which might be very complete and suitable for an Arctic journey
or a very cold climate must obviously be unsuited for a journey in
tropical countries, though it might contain some articles useful in all
regions. And even where the conditions may not be so wholly dissimilar
as in the cases mentioned, as, for example, in Soiith America, Australia,
and Central Africa, the traveller will in each country require many
distinct articles, and find others superfluous. In all cases where special
information is needed, the intending traveller will do well to apply to
the officials of the Geographical Society, who, as a rule, are able to put
him into communication with the best authorities of all — his last pre-
decessors in the region he is about to visit. He may also obtain much
useful general information from Mr. F. Galton's 'Art of Travel,' and
Messrs. Lord and Baines's ' Shifts and Expedients of Camp Life.' For
more detailed information as to particular branches of his outfit — e.g.,
Scientific Instruments, Photographic Apparatus, Medicines, or the para-
phernalia of a naturalist, he should also consult the chapters to which
references are hereafter given, and the Eeport on Eqxupment, published
(1892) by the Alpine Club, to which is appended a useful list of
addi-esses of trade-firms. His next step will be to visit some great
London outfitters — e.g., Messrs. Silver & Co. of Bond Street, the Jaeger
Company, Princes Street, Cavendish Square, who supply a special
HINTS OX OUTFIT. »
mountain outfit, where he may see specimens of the goods that have
been supplied to travellers, and of the inventions they have devised.
It is not advisable to lay down any absolute rule as to whether the
traveller should complete his outfit at home or abroad. There may be
some occasions on which it may be best to complete abroad. Customs
duties in some countries, particularly Eussia and the United States, have
to be taken into account. But, inasmuch as far greater facilities of
purchase and for packing are to be had at home, the reasons would
have to be very weighty and exceptional which would render it desirable
to complete abroad.
Travellers, again, in some regions require to carry much of their food
with them, while in others they can obtain almost all necessary sustenance
on the spot. In some countries there are considerable facilities for
transport, and there is no need to reduce the baggage to very small
dimensions ; in others the difficulty of transport is amongst the greatest
to be encountered. These various considerations must all be taken into
account, and the leader of an exploring expedition will give the first proof
of his fitness by showing, by judicious selection, that be appreciates the
relative importance of particular articles.
In the arrangement and packing of the stores there are, again, con-
siderable opportunities for the exercise of sound judgment.
On this subject some hints may be offered under four heads, viz. : —
methodical arrangement, security, economy, and the catalogue.
1, MetlodkaJ Arrangement. — Articles likely to be in most frequent use
, should be packed together, care being taken not to bring articles likely
to injure one another into close contact. Tins must be kept apart from
anything breakable. Fragile articles (such as glass bottles) should be
packed in small separate boxes or cases, so that, should they be broken,
they may not leave a void which will cause all the contents of their case
to jumble aboiit. Chemicals and explosives should be kept sejiarate from
other things ; and, before being packed, inquiry should be made as to
regulations to whicli they will have to submit on ship-board, &c. If
the goods have to undergo customs examination, the traveller must be
present himself, or he risks the goods being disarranged and carelessly
repacked, and the eatables extensively tested by tasting.
2. Security agaiust (o) breakage, (h) damp, and (c) rol:)bery should be
studied whilst packing.
10 HTNTB TO TRAVELLERS.
a. To guard against hreakagc, packages shoukl be of reasonable dimen-
sions. For an inkand traveller 75 lbs. gross weight skould be about the
maximum of any single package. A horse or mule can take a (con-
veniently shaped) box of this weight on each side, and 50 to 60 lbs.
between them on the top. Where goods are intended to be carried by
porters, it is not recommended that any single package should weigh
more than 50 lbs. Heavier packages will almost certainly have to
submit to very rough treatment. Further security against breakage can
be had by sub-division, that is to say, by packing boxes inside boxes, tins
within tins, &c. Everything should be tightly packed, and all vacant
spaces filled up. Oblong boxes travel best. The air-tight packages
manufactured by Messrs. Silver & Co. are recommended, but for a
prolonged journey require to be protected by outer wooden cases. On
reaching the point beyond which goods must be carried over rough
country on the backs of animals or men, siich cases will conveniently be
exchanged for saddle-bags made of strong waterproof material. Each
pair of saddle-bags should be arranged with shoulder-straps for the use
of porters. A few large bags of the sort known in Tyrol as Rucksacks —
made of Willesden canvas, of which various approved sizes can be got at
Silver's — are most convenient for the carriage of small packages, and when
not in use are so light that they can easily be stowed away. It is
obviously desirable that some of the packages should be capable of
being kept under padlocks. Several canvas bags and several dozen
linen bags are very useful for packing.
I- b. To guard against damp (on ship-board, iu countries with heavy rains,
passage of rivers, &c.), all perishable things should, where practicable,
be enclosed iu tin and Holdcred, particulai' care heing taken that everything
is thoroughly dry before being soldered up. It pays the traveller well to
have his outer wooden cases made of the best deal, closely fitted, and
varnished or double varnished to prevent absorption of moisture by the
•wood.
c. Closely-fitted, well-made cases afibrd great trouble to thieves, and
gaping packages, with partly-exposed contents, invite robbery. Boxes
which are screived down are more secure than nailed boxes, as thieves are
frequently not provided with screwdrivers. Use trass screws, if possible,
for cases which have to be frequently opened and re-opened ; iron screws,
if used, should be tallowed before insertion ; they will then unscrew more
HINTS ON OUTFIT. 11
easily. Articles of value should be kept out of sight as much as
possible.
3. Economy. — It is false economy for the traveller to buy any but the
best articles for his outfit, or to carry useless things. Many articles
may be put to double uses, and economy can be effected by selecting such
materials as can be most widely applied. For example, articles to be
used as presents may also be put to use on the journey. There should
be no waste space in the packages. Every interstice can be filled up with
articles which may be turned to account. For the finishing touches tow,
cotton-wool, and paper, crumpled into balls the size of walnuts, may be
advantageously emj)loyed, as all these materials can be used for a diversity
of purposes. If the traveller does not himself superintend the packing
of his goods, he must not expect foresight in these small but important
particulars.
4. The Catalogue of Outfit. — As each package is finished its contents
should be carefully catalogued, and the package numbered distinctly on
several sides, corresj)ondiug numbers to be entered in the catalogue. In
the event of the contents of a box being varied and numerous, roughly
classify them before entering. The traveller himself should carry the
catalogue on his i:)erson, and, where there are a large number of packages
and articles, it will be found of .advantage to form a classified catalogue
showing the disposition of the articles, as well as a numerical one showing
the contents of each package.
The articles which go to make up a more or less complete outfit may be
roughly classified under the following heads:—!. Provisions; 2, Clothing;
3, Instruments; 4, Stationery, note-books, books and maps; 5, Appli-
ances for collecting ; 6, Articles for presents or barter ; 7, Camp equii>
ments ; 8, Medicines ; and 9, Photographic Aj^paratus.
1. Provisions. — The following are good for all countries and all
climates : — tea (in tins) ; preserved milk (Milkmaid Brand), or cocoa and
milk (in tins); arrowroot; Liebig's extract (sold usually in jars, but will
keep equally in well-soldered tins) ; preserved soup in tins ; Bovril ;
Edwards' Desiccated soup; Silver's self-cooking soup tins (invaluable in
any emergency when a fire is impossible) ; sardines (in tomato sauce) ;
potted bloaters; Symington's i^ea-flour soup (excellent at low tempera-
tures, and requiring only one minute's boiling) ; lemonade efi"ervescing
powder (will keep perfectly if soldered in tin); oatmeal and baking
12 HINTS TO tkavetj,7:es.
powder; driccl onions ; eating raisins; cliocolate in cakes; mustard, salt,
pepper, and curry powder ; marmalade in corked bottles ; Chelsea table
jelly ; Moir's fresh herrings; and Erbswurst. Jam in J lb. tins.
Kola-nut biscuits have marvellous effect in sustaining strength during
exertion. They arc to be had of M. Gaucher, St. Earnabe, Banlieu de
Marseille, and cost 2 fr. 50 c. the kilogi'am.
Preserved meats can now be procured in nearly all civilised towns, and
in most instances will keep for an almost unlimited length of time.
When purchasing, all tins should be inspected, and huJged or hattered ones
should he rejected. A convex end indicates putrefaction inside. The liest
course is to purchase direct from general providers or makers of esta-
blished reputations. A small box with screw-on lid for holding salt.
Empty provision-tins are often highly appreciated as presents, and the
larger can be utilised also for natural history specimens (birds and
mammals) ; the smaller for shells, insects, &c.
2. Clothing. — Woollen goods are to be preferred for all countries and
for all climates. Boots should be amply provided, and be got into wear
before departure ; they should be broad-soled, not too thick or heavy,
and one pair at least large enough to admit of two i^air of socks being
worn. Double socks and easy boots are the best prevention against frost-
bite or sore feet in long marches on rough grovmd. Porpoise hide is
worth the extra cost. A supi^ly of nails should be taken. An " ulster "
coat, one or two sizes larger than a fit, will be found useful to sleep in.
A stout mackintosh will keep all but the legs dry on a long march, and
in temperate climates at least is very serviceable. In the tropics the
light oil-skin coats now made will answer the same purpose. Travellers
who have been in, or near, the districts to be visited, should always be
consulted as to what specialities may be required. The People's Button
(A. & N. Stores) fastens to the clothes without the need for sewing.
Silver has a good form of Hus'if. Eubber-gloves. Leather-belt with
pouches, swivels, &c. Bootlaces. Have a pair of long, warm boots for
tent wear, and a pair of long over-all rubber boots for slipping on to go
out of the tent in snowy or muddy places.
3. Instruments. — (See Section TV.)
4. Stationery ; Note-hoohs ; Books and Maps; Despatch box, a small
copying roll, stylographic 2'>ens, and ink-bottle in uvoden case. — The descrip-
tions of paper most useful are bank-post, tissue, and botanical. Note-
. HINTS ON OUTFIT. 13
books should be made out of bauk-postj be bound in parchment, and
have gilt edges. It will be found a great convenience to classify observa-
tions into separate books, or distinct divisions : (a) an angle-book for the
survey observations, barometric, &c. ; (b) a general note-book ; (c) notes
on and numbers of natural history specimens. Such classification must
be effected sooner or later if the observations are to be turned to account.
Tracing-liueu (sometimes called tracing-cloth) is more useful than
tracing-^joper. Strong envcloi3cs and of large size. Labels, adhesive
or tied, according to the climate, for bottles with natural history speci-
mens, should not be forgotten. Perry's ink pellets ; a little blue and red
ink for the map, and some indelible brown which can be painted over, a
good portable inkstand, and steel pens of various descriptions should be
taken. Brandauer's " Oriental Pens " are recommended for fine work.
Sketches and notes, particularly the records of angles, in pen-and-ink are
to be preferred to the same in pencil, as the latter often become illegible.
The nature and the extent to which the traveller should take books
and maps must be determined by his jDarticular circumstances. A few
sheets of sectional paper (i.e. paper with printed lines crossing at right
angles) will always be found of service for making maps and plans.
5. Apjjiiances for Colledinrj. — (See Section VIII.)
6. Presents and Articles for Barter. — Clasp-knives, of all sorts, are
esteemed. These are most advantageously obtained direct from Shelfield
and Birmingham manufacturers of repute. Spectacles are useful in
many countries. Small musical-boxes, hunting-whips, field-glasses,
flasks, tea, tobacco, coloured pocket-handkerchiefs, snow-spectacles, card-
board plates with coloured pictures, "Waterbury watches, and whistles,
are all frequently ai^preciated. Beads are good in many parts, but
judgment is required in pui'chasing only those sorts that are generally
in fashion. Information should be sought from previous travellers.
Birmingham and Venice are the principal centres of the bead manufactiu'C.
For almost all wild or partly-civilised countries special articles may be
usefully carried. Inquire beforehand.
A few simjile conjuring tricks, and the knowledge of how to show them
off, are often of the highest u.se to travellers in winning the esteem and
respect of their temporary hosts.
7. Camp Equipments ; Tents; Coolcing Stoves ; Filters; Tools; Ar7ns. —
For Africa and hot climates generally, and where the traveller can live in
14 HINTS TO TRAVELLEKS.
his tent, it should be square, double-roofed, and fairly roomy (see p. 25).
For very rough travelling, or for journeys on which it is desirable to carry
only a moderate amount of impedimenta, the pattern of Whymper's
Alpine tent is recommended. Tents of this nature, 7x7x7 feet, form
a modeTate load for one man. Messrs, Silver have the pattern; the
material should be " Willesden canvas," which has been found altogether
waterproof. The tent should have a small window at the back. It is
well to have an extra mackintosh iloor loose. This should be one foot
larger than the floor of the tent, and have tapes attached, which tie to
corresponding loops on the canvas. Several extra waterproof sheets
of various sizes are sure to come in handy to cover luggage, &c. One
Whymper tent (Edgington's), for a mountain journey, for each man ; in
hot countries extra fly is needed. The tent should loe made to open at
both ends, and the floor should be continued up at both ends and fastened
so as to stand in a vertical position to a height of at least 6 inches.
Take two spare poles and spare Willesden canvas. A very light form of
tent, for the use of mountaineers and others, has been invented by Mr.
Mummery. It holds three men and weighs 3k lbs. Tents of this kind
may be seen at Edgington's ; they are capable of improvement by the
addition of a floor,
Jaeger's sleeping bags are warm enough for all ordinary cold. Eider-
down bags are recommended for greater cold; each bag to be made
with 2 lbs. of best eider-down ; a woollen cover to be sewn over the sattecn
lining both inside and outside the bag ; or, have two bags similarly made,
with 1 lb. of eider-down each, and use them singly or in combination.
Stool and Table. — An artist in troi^ical countries or snow regions must by
no means fail to carry some form of artist's umbrella or light sketching tent.
Bough Towels. — Buckingham's 1-snood, 4:-snood, 8-snood, and cable-laid
twines are recommended,
Eubber pocket-flasks holding one pint,
Kananga water (Japanese) to rub on hands and face, as a protection
against mosquitoes. Tins of mustard leaves.
Filter. — A good "traveller's filter" is desirable. The "Explorer" is
the most satisfactory for providing small quantities, Abyssinian pocket-
filters are recommended, but are of no use for the supply of large
quantities. A piece of mackintosh sewn up in a cone shape, with cane
or wire round the large end to distend it, and with a piece of sponge
HINTS ON OUTFIT. 15
fitted in the neck, is better than nothing. Not only filter thoroughly,
but also boil the water. Too much trouble cannot be taken to obtain
pure Avater. More travellers have probably lost their lives through fever,
and through drinking bad water than from all other causes put together.
For carrying water for use on the march (or other liquids), Silver's
ebonite flasks, felt-covered, with attached straps and cups, are
recommended.
Cooking Stoves, &c. — Some knowledge of how to cut up an animal or
prepare a fowl for the pot is very useful; and the more the traveller
knows of simple cookery the better, for if he should not cook himself,
he will be in a position to teach others. He should, whether he will use
it himself or not, take pains to select before starting the form of portable
cooking apparatus best suited to his purpose. Handles should be riveted,
not soldered. Small bellows are useful. Enamelled iron cups and plates,
knives, forks, and spoons must be added. (For lanterns, see p. 72.)
Eob Eoy cooking-stove, and Warren cooking-pot.
A supply of fish-hooks and lines of different sizes is very useful ; given
out to the men in camp, they will often enable them to sui:)ply themselves
with food.
Take strong riding-whijDS, and strong twine and whipcord. The best
twine commonly made is called "page-cord" (used by compositors for
tying lip pages of type). If rope is wanted, use Manilla.
Tools, dtc. — A small leather roll, containing a chisel and a gouge or two,
a small hand- vice, two files, one A gimlet, bradawls, small metal punches,
and cold chisel, wire-nippers, j)incers, screwdrivers, French nails and
screws, and small fine saw, most serviceable for mending broken articles,
if the travellers can use them. Leather shoemaker's awl, waxed thread.
Small bellows, and a few bundles of firelighters. A light axe, and tin-
opener. Buck, Holborn Viaduct, supplies excellent tools. Gum and
liquid glue. Copper rivets of various sizes, and pinchers to cut the ends
off. Butcher's Terror for making uj) loads. Lead seals and vice. Leather
punch. Two-handed screw- diiver, a jemmy, link-spanner, leather punching
plyers. Materials and tools for mending and nailing boots, including
shoemakers' thread and cobblers' wax.
Arms and Ammunition. — The nature and extent of his battery will
be matters for the traveller himself to decide. For rough travel it is a
question whether muzzle-loading guns may not be better than breech-
16 HINTS TO TRAVELLERS.
loaders. Should the latter be taken, a good double gun and a double
Express rifle are useful, and also a " Transvaal," with shifting barrels for
shot or bullet. Eevolvcrs are more useful for the moral effect they
produce than from any actual service they render.
8. Medicines. — (Sec Section III.)
9. Phvfof/raj)hic A]>paratus. — (See Section V.)
Tlic following preliminary lists of Eequisites, compiled chiefly from the
catalogues of some of our principal outfitters, make no ])retence to be in
any way complete. Some of the articles may be superseded by improved
appliances and new inventions, or may be superfluous for travellers who
have not the same means or aims of those who have supplied the lists.
The traveller need not be discouraged if unable to secure completeness,
for some of the greatest journeys have been made with very inadequate
resources. The object here is to give him the means of selection. In the
details of the process he must, as has been said before, guide himself by
the special circumstances of his journey.
The traveller, whose aim is to be in light marching order, may first be
given a general admonition to see that he has suitable warm and light
clothing, proper medicines, a serviceable cooking-aj^paratus, which need
weigh little more than a kettle, and concentrated forms of food to fall
back on in case of need, and such saddlebags or forms of packages as
may be suited for the mode of carriage he will employ.
So7ne Bequisites for a Tropical Tour —
Double-lined tent ; camp bedstead ; folding tables ; field hammock ;
mosquito curtains, or insect-jDuzzler, on ]\Ir. Tuckett's plan (see
post); head-gear and clothing (see p. ); stout shooting-boots;
canvas shoes; leech-gaiters,* rug, or plaid; lined umbrella, for
* Colonel Godwiji-Austen says: "An eifective way to prevent leeches attack-
ing the ankles and legs, is to wear woollen stockings ; then over them, round the
legs, ixitincas, the woollen bandages as worn in the Kaslouii- Himalaya, and now
served out to oiu- troops on mountain service in India. Then, lust, a jiair of
cotton socks tied above with tape. After adopting this plan in the Terai and
Assam I never got bitten." Stout cloth gaiters with straps, not buttons, are
preferred by many travellers to leather. They are lighter, warmer, and resist
snow better.
HINTS ON OUTFIT. 17
sun;* bags, saddle, aud valise; hunting-knives; patent ebonite
water-bottle, covered in felt, -with cups ; waterproof despatcli-box.
Some Requmtes for a Tour in Gold Climates —
Whymper's tent; flannel shirts; under-waistcoats and drawers;
long lamb's-wool stockings ; woollen suit ; fur coat, gloves and
knitted sleeping-cap covering ears ; flannel or blanket belt ;
woollen jersey comforters ; Swiss woollen lined slippers, snow-
shoes; mocassins; hair eye-screens; wool, or fur rugs; warm
gloves, mittens, and portable lanterns.
Patent Norwegian cooking apparatus ; sleeping-bags of woollen
material or skeepskin, essential in high mountain excursions
(Mr. Tuckett's pattern may be obtained at Silver's) ; canteens,
fitted with enamelled iron ware ; waterproof bags ; tan canvas kit. ■
See also Alpine Club Report.
List of Mr. Whtmpek's South American Outfit.
The following list of articles taken by Mr. E. Whymper is given as
representing the maximum outfit of a scientific explorer and mountaineer
in a semi-civilised country. Thougli few will be able, or need, to imitate
its completeness and scale, it may be useful for reference and selection,
and is therefore given here in extenso — with the exception of the photo-
graphic apparatus, which have been superseded by the progress of
the art.
Stationery, &c. —
Stencil-ink, brushes, and stencil-plates (various).
2 " Traveller's Inkstands" (Hachette's) ; inkstand in case.
Steel pens (various), including very fine sorts; stylographic pen.
Drawing pencils, brushes, pen-holders, aud letter-fasteners.
Parchment and gummed labels (various), 6 gross in all.
Tissue paper (useful for various purposes, including photographic
printing).
* For survey -work it should have a long handle, in two pieces or joints, the
lower joint bei'ig .spiked to fix more firmly in tlie ground.
c
18 HINTS TO TRAVELLERS.
Bank-post ; cream-laid pai)crs (various sizes) ; blotting-paper.
Stamped and plain envelopes (various) ; canvas envelopes.
4 doz. memorandum books ; sketch-books; gum; ox-gall; red tape.
Tracing-paper, and a roll of tracing-linen ; ferro-prussiate paper.
Drawing-pins; penknives; Chinese white and water-colours; 2-1'oot
steel rule.
Note-books, bound in parchment, with clasps; photographic register ;
journal and general note-books; daily notes; angle-book; boiling-
point book ; catalogue of collections.
Maps, Boohs, &c. —
Admiralty charts, maps, and works of importance, for reference on
the spot.
Dictionaries and grammars for languages spoken in country to be
traversed.
' Hints to Travellers ' ; Lockyer's ' Astronomy ' ; Bethune's ' Tables ' ;
'Admiralty Manual'; 'Sailor's Pocket-Book'; Frome's 'Sur-
veying.'
Clothing, tfcc. —
9 towels; 12 flannel shirts; 2 white shirts; 16 jiairs angola socks;
26 pocket-handkerchiefs ; 3 neckties ; 6 shirt-collars ; 3 pairs
mountain-boots ; 1 pair ordinary boots ; 1 pair lawn tennis shoes
for shipboard ; A. suits, woollen, various thicknesses ; dress siiit ;
Panama straw-hat ; Arctic cap ; travelling-caj:).
Eed felt for tablecloth ; large sponge and several small pieces ;
tooth-brushes ; very thick woollen jersey ; 2 rowing " sweaters " ;
2 woollen comforters ; 2 neck-wraps ; 3 pairs knitted woollen gloves ;
1 pair woollen mits; 2 pairs leather gaiters (own pattern) ; 2 linen
masks (for snow) ; 2 woollen head-pieces ; folding felt slippers ;
cork soles ; small pieces of mackintosh (various) ; several hanks
whitey-brown thread ; several pieces inch- wide ta])e ; dusters and
cloths ; common pins, «ewing-needles, and packing-needles ; down
dressing-gown ; very long i;lster coat.
MisctUaneous. —
Two tents (own pattern) 7x7x7 feet, packed in stout canvas bags.
Sheepskin rugs laid down on felt.
HINTS ON OUTFIT. 19
Waterproof sheet 10 x 10 feet.
„ „ 6 • 6 X 6 • 6 feet.
4 bags of forfar (to be stuffed with hay for beds).
4 „ „ ( „ „ „ pillows).
Various bags (to be filled with stoues or saud to keep tlie tents firm)-
i'our 100-foot leugths of Mauilla rope ; 6 ice-axes.
Various uiaekiutosh and leather courier-bags and knapsacks.
Mosquito-nets; various bags of forfar; tin flasks and cans.
2 pint ebonite bottles, felt-covered, with straps (Silver's).
Cooking apparatus (from Nares' surplus stores), with attached
pannikins, and small ditto.
Water-tank, with filtering sponge and tap; 2 pocket filters.
Salter's spring balance, Aveighing to 25 lbs.
Double gun, by Holland & Holland (rifle and shot), shot (various),
gunijowder, &c.
Night-lights and candles ;' folding camp-chair.
Insect-net; botanical collecting-book antl paper.
Knives for opening tins ; brass spirit-lamp.
Geological hammer.
li lbs. tobacco; cigars, cases, pouches, pipes; flint and steel.
14 cakes soa^) ; camphor.
Balls of sti'ong twine (various) ; screws and nails, various sizes.
3 gross glass bottles (various sizes) for insect collecting.
Medicines (various).
I'nscnls, (fcf. —
500 bead necklaces (amber, tuniaoise, &.r).
250 silvered and gilt crosses, various patterns.
150 pairs of earrings and brooches.
300 eye-protectors (green, blue, white, and neutral tint glasses).
72 gilt and silvered watch-chains.
21 pairs of spectacles and eye-glasses.
18 tin dishes fitting one inside another j
25 „ plates [ (used also in cookery).
36 „ spoons }
Silver toothpicks.
2
20 HINTS TO TRAVELLERS.
Keyless silver watch.
25 good pocket-knives, variou.s descriptions.
G corkscrews.
Small tape measures in brass cases.
Various plated goods.
1-2 circular looking-glasses.
12 mouse-traps.
J ndrutuotls. —
Silver lever watch; gold pocket-chronometer; independent seconds
watch.
Itepeating travelling clock, with alarum.
G-in. sextant (Cary).
3-iu. transit-theodolite (Casella).
2 theodolite stands.
2 mountain mercurial barometers, Fortin (Hicks).
I niercni'ial standard barometer.
I I boiling-point thermometers (various makers).
Henderson's boiling- water ap]:)aratus (Hicks).
8 aneroid barometers (Hicks, Casella, Hilger).
Telescope in sling case; field-glass in aluminium.
Thermometer in metal tube, for i)Ocket.
Case containing maximum, minimum, and clinical thermometer.
Prismatic compass ; various pocket-compasses.
Multiplying winch and measujing line.
Metallic measuring tape, 50 feet (Chesterman's).
Case of mathematical instruments.
Drawing-i^ens (various) ; Napier's com])asses.
Travelling combination pocket-knife ; corkscrew and whistle.
liussiau furnace.
Magnesium riband.
Small musical-box.
Screwdrivers (various).
Clothing, instruments, and valuables were packed in aii'-tight metal
uoiform-cases, with outer double-varviished wooden cases. Provisions
and the bulk of the goods were packed in tin, and soldered down, inside
HINTS ON OUTFIT. 21
double-varnished close-fitting wooden cases. Cliemicals and articles
likely to be injured by damp were in double tin cases, soldered down
separately one over the other. The majority of the cases measured
28? X llf X IO5 indies. This was found a very convenient shape for
mule travelling.
The whole, including provisions, amounted to 42 packages. Gross
weight aboTit 2300 lbs. Total cost of journey £1750, exclusive of cost of
instruments and plant brought home in good condition.
All the articles enumerated in the above lists were taken out from
England, and scarcely anything, except part of our foorl, was purchased
in Ecuador beyond the following articles : —
Waterproof capes (ponchos); woollen ponchos; saddles; riding-
whips; machetas.
These articles could have been obtained of better quality and at less
cost in England.
Ed. "Whtmpee.
Fehruary, 1883.
The Tuckett '• Insect-Puzzlek."
The form of protection, described on next page, from insects and vermin
of all kinds is extremely portable, and has been found equally useful in
camp and in native huts. As it is not generally known, except to
Alpine travellers, it is described fully. It can be procured at Messrs.
Silvers.
Take two pieces of cedar or mahogany board, fV of :^n inch in thickness,
16 inches in length, and o in width, and attach them endwise to one
another by a hinge, or by ])ieces of stricg lacing through corresponding
holes, so that they may be folded together for economy of space. At the
centre of, and one inch from, the outer extremity of each board, insert very
securely a female screw in brass, into which can be screwed uprights of
bamboo, 18 inches in length, and about half an inch in diameter. By
means of these and three light detachf-d canes, each about 17 inches long
and furnished with sockets, an arch aliont 34 inches in height, and of
considerable strength, is funned.
22
TTTXTS TO TT^AVET.LET^P.
If greater he.afl-room is desired, the length of the bamlioos mny be
increased, and other dimensions may l>e modified to snit individual
preferences.
Fig. 1.
,' Foot
Having inflated vpitli small portable bellows an india-rubber mattress,
7 feet in length, and 26 inches in width, made in two attaclied sections,
A and B, Fig. 1 (a cork one may be snbstitnted, or the contrivance may
be nsed without any mattress at all), place the nnited boards underneath
it at 10 inches to a foot from the head-end, as in Fig. 1, and the mattress,
or the weight of the body if no mattress is available, will keep the boards
and arch firmly in position.
Standing across the foot of tlie mattress, draw over and under it a
covering, made somewhat of the shape of the foot of a sock, of which the
HINTS ON OUTFIT. 23
under portion in contact with the gronncl, and the sides and " toes " for
a height of a foot or more above the mattress when in position, are made
of strong unbleached linen, whilst the ripper part is formed of "nain-
sook."
Pull the bag thus constructed backwards under the'mattress, and over
the top of the arch (securing it to the summit of the latter hy pieces of
tajie sewn on inside), and then, creeping feet forenjost from behind
through the open end into the interior, draw in the pillow, reef up from
inside, by means of a tape, the open end of the bag, and, winding the
slack round until the material is tightly strained, secure the centre with
a bow.
Thus all access of vermin or mosquitos is absolutely ciit off in every
direction, and the protected person, invisible himself, but able to see
those outside, can sleep in peace, or read undisturbed, either by day or
by the light of a candle (placed outside on a chair or stool), which passes
freely through the "nainsook" envelope.
Such an arrangement in feverish districts affords at least some protec-
tion against malaria. (See p. 47.)
Mr. Mummery's Tent.
Mr. Mummery, of the Alpine Club, has devised and tested in actual
use a form of tent which holds three men easily, and weighs only Sj lbs.
Tents of this kind can now be purchased at Edgington's. The area
covered by the tent is 6 feet long by 4 feet wide. The end of the tent is
of the form of a rectangle surmounted by an isosceles triangle.
Me. J. Thomson's Notes.
The following outfit was provided by Mr. Thomson for his journey
across Masai Land in 1883: — For carrying my clothes, books, &c.,
8 boxes, of different sizes, watertight, tcell roumhd at the edges, not more
than 10 inches deep, and not very wide, so that they may be easily
grasped when on the shoulder or head. The larger boxes are for carrying
24 HINTS TO TRAVELLERS.
clothes only, tlic smaller for u mixture of clothes with heavier articles,
such as books, boots, &c. None of the boxes when filled to ■weigh over
60 lbs.
For clothing I have jirovided 1 ordinary suit of tweed clothes for the
colder regions, 3 suits of tropical tweeds, and as many of white drill ;
6 strong loose shirts, with pockets, and as many thin jerseys; G pairs
of thick wooUeu stockings or socks; 1 pair of strong boots, for wet
season; 2 pairs of lighter make, for the dry season, and 2 pairs of
canvas shoes for cam^D use, and when feet are sore. Heavy boots are to
be condemned for the tropics, as the feet soon become scalding hot,
making travelling in the heat of the day most painful.
Canvas gaiters are of great use, to keejo mud out of the boots when
tramping through sw^amps, and to protect the legs in thorny scrub. A
tropical waterproof and a comfortable ulster make up the clothing list,
with the addition of such minor articles as handkerchiefs, scarves, &c.
"We have next to consider camping requirements.
I have formed a very decided opinion as to the necessity of the African
traveller making himself as comfortable in cam]) as the circumsiances and
the exierd of the expedition will permit. The climate is so trying rmd
varied, that to attempt " to rough it " unnecessarily is simply to iuvite
disease, and too often death.
Impressed by exj^erience with these convictions, I have been careful to
select a fairly roomy tent, 9 feet long, of good canvas. An iron bedstead,
with cork bed, and two warm Austrian blankets. A folding chair, cami>
stool, and a small portable table. The latter is an immense convenience
when much writing has to be done.
For short, qiuck trips, in which I might be away from camp for a day
or two, I have provided a jjalkee hammock, which forms a bed and tent
in one.
For carrying any sick person an ordinary string hammock is taken.
A mosquito curtain makes iip the list of camj) furniture.
Instead of carrying an ordinary bucket canteen I have had a basket
fitted u]) with all the necessary articles.
I, of course, take with me a small medicine-case, specially fitted with
a view to the treatment of fevers, diarrhoea, dysentery, liver disease, &c.,
and besides, I have been careful to have some of the more useful medicines
in separate bottles in case of accidents.
HINTS ON OTTTFIT. 25
Among otlior useful articles, the following maybe mentioned: — Water-
proof gronnd sheets ; roll-np case of tools ; one • 577 Express rifle, one
•577 reduced to '450, a 12 bore gun, a revolver, with ammunition to
suit ; two axes ; a hunting knife ; two liill-hooks and two reaping-hooks,
to be used in camijing and cutting a way through jungle and forest;
diary and necessary stationery; some books, especially such as can bo
read and re-read.
These articles, with scientific instruments, photographic apparatus, &c.,
form the chief part of my ecpiipment.
I have not thought it necessary to lay in a supply of stores, such as
tea, coffee, sugar, &c., as they can be got almost as cheaply in Zanzibar.
Goods for bartering miist also be got there, as I should otherwise run the
risk of taking out what woixldj to a large extent, prove to be xitterly
worthless.
As the country through w'hicli I have to pass is reported to 1)6
dangerous, I shall arm as many of my men as possible with short Snider
rifles, and take revolvers for myself and the leaders.
December 3, 1882.
Mk. H. H. Johnston's Notes.
I have been asked to add a few hints on an African outfit. Perhaps
the simplest plan will be for me to give a brief sketch of the way
in which I myself travel in the interior of Africa. I have made foui'
more or less extended journeys in Africa since 1879, visiting a great
deal of the northern part of the continent, the western and the eastern,
and my present form of outfit is one that experience, and perhaps
individual taste, have gradually formed to a character which I find
decidedly conducive to comfort and true economy. Firstly, it is to be
supposed that one's baggage must be packed in a -way that will render
it readily adaptable to porterage, either on the heads of human porters or
on the backs of beasts of burden. Consequently, the heaviest sci)arate load
should not be as a rule heavier nor larger than a man can carry, therefore
you sliould arrange to pack all your goods in parcels not weighing more
than fifty pounds. In exceptional instances, such as a tent or a bed, where
the article is one and indivisible, and exceeds the weight mentioned, it
26 IITVIS TO TRAVEIJ.FKS.
mnst be fastened to a pole, and arranged so that two or more men — if
porters are tlic only means of transport — can carry it. For secnrity
against robbery, for compactness, lightness, and, above all, resistance to
damp, there is nothing better than air-tight tin cases, measuring about
forty inches by twenty-eight, with good locks and handles at each end.
Cases of this description are cheaply made by Messrs. S. W. Silver & Co.
It is well that there should be the same lock to all the boxes, so that
one key — which you can attach to your watch-chain or hang aroimd
your neck, keeping a duplicate in your dispatch box— opens all.
Special instructions are given in other ])arts of this volume as to a
scientific outfit for tlie prosecution of special studies in various branches
of science, so that I shall say nothing about this subject, the more so as T
thoroughly agree with the practical usefulness of the suggestions offered
therein by competent authorities. The directions in natural history
as to outfit and instruments I have particularly put to the test, and can
recommend them as thoroughly practical, and emanating from the mind
of an experienced traveller. As to photography and medicine, I would
caution the traveller against attempting to be too elaborate, seeing that in
all the fatigiTCs and worries of transport he may find his chemicals and drugs
a horrid nuisance. With regard to drugs, indeed, as you cannot hope to be
an accomplished physician and the healer of all ills with which you come
in contact, you would do well^to confine yourself to a few simple remedies
for simple forms of sickness, and these should be taken in large quantities.
Quinine is the traveller's sheet-anchor. It is best procured from Messrs.
Howard & Son, Stratford, E., who will, if necessary, supply it in a
compressed form in small cakes. This is by far the best and most con-
venient mode of carrying quinine about. To roll your dose of quinine up in
cigarette paper into a small pill, to moisten it with the tongue, and place
it at the root of the tongue and swallow it, is the matter of a minute.
Other useful and simple drugs that do not require mTich measuring or
preparing are : Cockles' pills, as an aperient, Lamplough's pyretic saline,
chlorodyne, opium, in the shape of laudanum, for sudorific purposes,
castor oil, sal volatile, and Dover's powders. Vaseline and zinc ointment
are excellent for the sores and ulcers of the tropics, and violet powder is a
good thing to dust over the body, especially between the folds of the skin,
where pei-spiration is likely to acciunulate, in order to absorb and sweeten
the excessive sweat poured out from the pores of the skin.
HINTS ON OUTFIT. 27
As regards tents, the traveller must endeavour to judicionsly combine
comfort with portaliility. He had better go to Silver's or Edgington's in
tlie City, and choose for himself ; but he should take care that he assure Idm-
sdf, first, that the material of the tent is absolutely rain-proof, and secondly,
for hot climates, that it is double-lined, -with a space between the two linings.
Tliis is absolutely necessary for the tropics, or the interior of the tent nnder
the sun's rays becomes intolerable, unless there is a current of air passing
between the two linings. I obtained a cheap and comfortable tent for
my Kilima-Njaro expedition at ilessrs. Silver's. If possible, a second, or
even a third, tent should be taken for the use of one's personal servants,
and for housing such of the baggage as cannot be taken into one's own tent.
If an extra tent or two is placed at the disposal of the men, it has a
wonderful effect in reconciling them to the severe discomforts of a journey
in rainy weather.
Two most necessary items of any African outfit, however small, are
a portable table and a stout portable chair, and it would be better if the
traveller took two or three chairs with him (as they are very light and
portable) so as to be able to offer a seat to any native of importance who
may visit his tent — an attention generally much appreciated.
With regard to food : the traveller must be guided a good deal by his
own tastes in eating and drinking. He has every opportunity of pleasing
himself by selecting from the lists of provisions furnished by some
of the great provision merchants of London, such as Messrs. Fortnum
& Mason, Messrs. Crosse & Blackwell, and Messrs. J. T. Morton ; but I
woiild specially urge on him, if he is visiting the tropics, the absolute
necessity for extreme moderation in the use of alcohol. Indeed, it is
better to go to the extreme of abstaining altogether than to go to excess
in this matter, which is remorselessly punished by nature. At the same
time, alcohol is a valuable medicine and should not be excluded from the
traveller's repertory. For an expedition not likely to last more than a
year, the following amount will be found siifficient : — Two dozen of good
champagne, three bottles of sherry, four bottles of brandy, and four^of
whiskey. Claret, burgundy, and port travel badly, although as tonics
and blood-making wines they are among the best. If the traveller is in
any part of Portuguese Africa he will probably be able to obtain the
excellent Vinho Tinto of Lisbon, whicli can be recommended as a very
wholesome wine. Except under extraordinary circumstances, such as
28 HTNTR TO TT7AVELT.E11S.
acoidonts, or deadly faintiioss, alfijlio] sliould never be taken in the day-
time, but reserved for the evening, and if the want of it is then felt, it
should preferably be taken in the form of champagne, or brandy or
whisky and water. The practice of so many German travellers of taking
small "quantities of neat brandy or other sjDirit in Africa is most deleterious,
and if pursued for any length of time will inevitably prove fatal.
If the traveller is a draughtsman, he should of course provide himself
with ])aper and artist's materials ; but these should be as simple as
possible, for the true artist can make an accurate and effective drawing
with very simple materials. These materials should consist of several
good stout note-books with paper of fair quality, ruled with faint blue
lines. Such will be very useful for hasty sketches made in conjunction
with written notes, and the traveller will find the blue lines assist him
greatly in the accuracy of his drawing. Two or three blocks of 'srhite
Whatman's paper, mounted with covers, and a pocket to contain loose
sheets, will be found sufficient for more elaborate drawings, either in
black and white, or in colour. These, for convenience, should be about
twelve inches by nine in size, and the paper shoiild be nearly smooth. A
good box of water-colours in tubes should be taken. The colours are
carried much better in tubes than in porcelain pans, for the latter are
liable to the attacks of insects, and are soon ruined by damp. The best
colours for ordinary purposes are the following : — Chinese Wliite, Lemon
Yellow, Mutrie Yellow, Orange Cadmium, Yellow Ochre, Eaw Sienna,
Burnt Umber, Vandyke Brown, Ivory Black, Antwerp Blue, French
Blue, Cobalt, Crimson Lake, Scarlet Vermilion, Indian Ecd, Venetian
Bed, and Emerald Green. An extra quantity of Chinese White and
liquid Indian Ink in small bottles, and Indian ]nk in stick, should be
taken for making black-and-white studies. The traveller will be siire to
make most of his minor and more rapid sketches in ink, and should be
sure that he has good writing-ink for the purjoose. Stephenson's black
ink is the best. For pencil notes the best pencils are F and H B, and
French Conte chalk in cedar. No. 1, will be found very useful, especially
when the work done in the chalk is gone over with a pen and finished in
ordinary black ink. This gives a very rich and solid effect to the drawing,
and, moreover, prevents the chalk from rulibing to a very great extent.
I have myself, in earlier days, lugged quantities of oil paints and canvas
about Africa with an amount of discomfort and worry quite dispropor-
HINTS ON OUTFIT. 29
tionate to the small results of an occasional study in oils, wliicli, if you
are any artist at all, can be done almost as effectively in water colours.
Indeed, except for the special purpose of indicating the colour of a man's
skin, or of that of a bird, or mammal, or lizard, or the tint of a flower's
corolla, I should recommend all travellers to confine themselves to black
and white in their reproductions of the objects of interest or the scenery
that they meet with, and not to inflict on us the feeble, washy water-colour
pictures which they intend to represent the grandeurs of tropical scenery.
As regu'ds food for the mind I cannot too strongly recommend all
tmvellers to supply themselves with quantities of light literature. By
" light," I do not mean frivolous in character, but devoid of great material
weight, so that it can be easily packed and readily transported. There
are a great many standard works now published in cheap editions in
palmer covers, and these, together with a supply of good novels, sensa-
tional tales, old magazines, and reviews, should be taken. Although
the traveller should endeavour to supply himself with books that are
worth reading and re-reading, still, it is astonishing with what i^leasure
lie will pe]'use the veriest nibbish in the wilderness, and really crave
for anything that may serve to distract his mind at times from the
savagery around him.
Finally, I would recommend such travellers as have not the time to
work out a systematic equipment for themselves, and who desire to spare
themselves trouble as well as time in the matter, to consult with Messrs.
Silver, of Cornhill, on the subject. This firm has supplied travellers,
including myself, with their outfit, and knows — or ought to know by this
time — exactly what is needed for every i^art of the globe. As they retain
lists of all the articles supplied for various expeditions, any one, by referring
to these lists — as for instance the outfit of my Kilima-Njaro expedition —
will be sufticiently guided in their choice.
Tor further information on '>ntjU, especially in arid countries, the
intending traveller is referred to p]). 'J-11 of IMr. Gallon's ' Art of Travel '
(5th Edition).
30 HINTS TO TRAVELLERS.
Canoking. — Bi) J. Coles.
Choice of a Vauoe. — In making choice of a canoe the traveller must
bear in mind that, in all i)robability, there will be rajtids in the river,
which will necessitate a portage being made, and that the canoe may
have to be carried over rough ground for a considerable distance. For
this reason, it is far better to take two canoes of moderate size than one
large one, beside which, a small canoe is much more easily handled in bad
water, and even should it become necessary to carry a large load, tliis can
easily be done by lashing two small canoes together, at about one yard
apart, and laying a platfoi'm across them, on which to place the stores, &c.
This, however, should not be done in dangerous and rapid rivers. The
following remarks do not, therefore, ajDply to large canoes, which, having
nearly the stability of a boat, may be handled in the same manner.
Paddles.— It will generally be found that the native paddles vrill be
best suited for the work. The double-bladed paddle, such as is used with
canoes in this coiuitry, is quite useless on a rapid and dangerous river.
Sail. — The sail should be made of duck, or some such light material,
fastened to a light yard at each end, and its hoist should be about twice
its breadth ; its size must be in proportion to the canoe, the hoist being
about one-fourth of the canoe's length. The mast should be as light as
possible, with a hole at the to^) for the halliards to pass through freely.
The end should be stepi^ed in a chock in the bottom of the canoe (when in
use), and it should be lashed to one of the stays, or cross-pieces of the
canoe. The sail should never be used unless the wind is steady and
abaft the beam, and the halliards should be taken to the after part of the
canoe in order to stay the mast, and secui'ed in such a manner that it
can be instantly let go, when the sail will at once fall, and imdue pressui-e
on the canoe relieved.
The Toiv-linc. — Too much attention cannot be paid to this important
article. It should be light, but of the best material (such as the rope
used by the Alpine Club), as its giving way at a critical moment ui a rapid
is sure to be attended with most serious results.
Loading the Canoe. — The packages should not exceed 50 lbs. in weight,
as they may have to be carried long distances over portages, and care
must be taken not to overload the canoe. Natives, who are aU good
CANOEING. 31
swimmers, and have nothing to lose by a capsize, are very apt to put
more into a canoe than is safe, so that it is a matter in which the
traveller should use his own discretion.
In ascending a rapid river, keep close to one of its banks, and endeavour
to take advantage of eddies. It will often happen that, owiug to the
strength of the stream, no headway can be made with the paddles, in
which case recourse must be had to poling or tracking. In the event of
the former, the poles should be straight and tough, and as long as can be
conveniently carried in the canoe. Natives generally stand up to pole,
but this the traveller should not attempt to do, or he will in all pro-
bability eitlier fall overboard, or capsize the canoe, or both. In tracking,
as great a length of line as possible should be used, as a sheer of the
canoe in a rajjid, with a short line, will often end in a capsize. Only two
men should remain in the canoe, one in the bow with a ijole, and the
other in the stern with a paddle to steer ; this man should also have his
pole handy. The line should be made fast to one of the stays in the bow
of the canoe, and never to a toiving mast, as in a boat; as in passing round
bad corners, or places where there are snags, and where it is necessary to
give the canoe a wide sheer, the leverage of the mast, if the line were
fastened to the top of it, would pull the canoe over. The man in the
bow, however, should always have his knife handy to cut the tow-line,
should necessity arise for his doing so. In tracking, when a river passes
through sandy soil, the men on the line should keep at some little
distance from the edge of the banks, as it is likely to give way under
their weight, and precipitate them into the river. Several men lost their
lives in Fraser Iiiver, in the early days of the gold discovery, by
neglecting this precaution.
In crossing from one bank of a river to the other above a rai:)id, be
careful to ascend the river for a considerable distance before attempting
to do so; and then make the crew paddle as hard as they can, keeiting
the head of the canoe, if anything, rather down the stream, as in the
case of a rapid river you would only lose ground by trying to light
against it.
In descending a river, the traveller should keep a look-out ahead for
snags and places where the river is narrowed in between hills, as in such
places there is nearly sure to be a rapid which may be so bad as to
render navigation impossible. In all cases before descending an unknown
32 HINTS TO TRAVELLERS.
rapid, he should land and inspect it throughout its entire leiiijth before
attempting to run it in the canoe. When descending a rapid, care must
be taken to keep steerage way on the canoe, as this will be needed to
avoid rocks, or whirlpools. These latter are very serious dangers, as tliey
generally do not remain fixed in one spot, but move about within a
certain distance of a centre. There are, however, in most cases, short
intervals when they break up, and tliat is the time to make a dash past
them. To attempt this when they are in full swing could only end in the
loss of the canoe and its occupants.
Boating. — By J. Coles.
When a traveller has to proceed for some distance overland before
reaching the river or lake he purposes to navigate, he must of necessity
l^rovide himself with a boat constructed in such a manner as to be
easily transported, either by being built in sections, that can be put
together and taken to pieces at pleasure, or by taking one of the
collapsible boats, sxich as Berthon's. If the former, he cannot do better
than to have one built of Spanish cedar, on the same plan as that which
was constructed for Mr. H. M. Stanley, by Mr. James Messenger, of
Teddington, with such modifications as may be necessary, when the
means of transport, and the nature of his journey, have been duly
considered. Collapsible boats, though very useftil for ferrying across
lakes or rivers, cannot, where a boat of other construction is available,
bo recommended for a continued exploration; they are, however, con-
structed of different sizes, and full particulars concerning them can
be obtained from the Berthon Boat Co., 50, Holborn Viaduct, E.C.
If the exploration is to be commenced at the mouth of a river, a whale-
boat will be found to be the best form of boat, for the following reasons.
Being steered by an oar, it is more easily handled in surf or a rapid ; it. is
generally faster than boats of the same size of ordinary build; it will
carry a good cargo, sail well off the wind, and is the best boat built for
crossing the bars of rivers, or lauding through a surf. Such a boat can
generally be purchased at foreign ports, with their oars and sail, and
should be well overhauled before starting.
Boat-sailing caunot be taught by any book, and certainly not by a
BOATIXG. 33
few short notes of this description. The traveller, tliereforo, who intends
iising a boat for exploration, should gather some experience before
starting, which can be done at any fishing village on the coast. This
will be the more necessary if he intends to use his boat on a lake, or for
sailing along the coast, from the month of one river to another, and the
following hints may, it is hoj)ed, l)e usefnl to those who have had Imt
small exjjerience in boat-sailing.
When under sail, never, vwler any circvwstimces, allow the sheet to be
made fast; a turn should be taken round a cleat, and it should be held
by one of the crew ready to let go at any moment. Do not let the crew-
stand up, or sit on the gunwale. When about to round-to, remember
that you cannot carry the same canvas on a wind that you can before it.
If caught in a squall, put down the helm at once, ease tlie sheet, and if
the squall is a bad one, lower the sail while it is still shaking. When
apjn-oaching a danger, such as a rock, do not stand on if you are in
doubt about weathering it, but go about in time, and have an oar ready
to help the boat round if she appears likely to miss stnys. Never carry
too much sail, as there is considerable danger in doing so, and a boat will
often sail faster with a reef taken in, than she will when unduly pressed.
If necessary to take in a reef when sailing on <i icind, do not luff, biit
check the .sheet, lower the sail sufficiently to shift the tack, gather the
sheet aft so that the men may take in the reef without leaning over the
gunwale, shift the sheet, hoist the sail, while the sheet slack, and
do not haul the sheet aft until the men are again in their places.
liowing. — This can only be acquired by in-actice, and though the
traveller will seldom be called on to take an oar himself, circimistances
may arise when he may have to do so, and we would, therefore, advise him
to learn how to handle an oar before leaving England. Under ordinary
circumstances, rowing on a river is sufficiently sim])le, and calls for no
sjiecial instructions. The case, however, is very different when a river
bar has to be crossed, or a landing made on a beach where a surf is
breaking, and in either case it will be well to remember the following
hints. On aj^proaching the shore, a surf when .seen from seaward never
looks so bad as it really is. Where possible, a landing should not be
attempted until opposite a village where the natives will be ready to
assist the moment the l)oat touches the beach. When the surf is heavy,
the boat should be backed in, prilling a few strokes to meet each heavy
D
34 HINTS TO TRAVELLERS.
sea, and then backing in again until the shore is reached. The great
thing to avoid is, letting the boat get broadside to the sea, as she will
then capsize; a steer-oar should always be used, as a rudder is of little
use in a surf, when backing in.
]n crossinff a har, if there is a good, strong, fair wind, it will generally
be best to cross under sail ; but if the wind is light or variable, this should
never be attempted. Wiien rowing, tlic crow should be cautioned to
keep their oars out of the water when the sea breaks round the boat, and
to commence rowing again as quickly as possible afterwards. As even in
the most experienced hands a boat will often be swamped on a l)ad bar,
it will be well, before attemjiting to cross it, to prepare for a swim by
removing all siiperfluous clothing, and see that everything tliat will float
in the boat, should be left free to float, while things that will sink, such
as fire-arms, &c., should be securely fastened to the thwarts.
The remarks given on canoeing with regard to loading, to ascending
and descending rapid rivers, are equally applicable to boating under
similar circumstances, with the following exceptions. lu towing, a short
mast should be used to which the line is made fast; this is stepped in the
same place as the mast, and should be stayed, so as to resist the strain of
the tow-line. Paddles will often be found useful in weedy rivers where
the oars get entangled. As a whale-boat empty will weigh about five
hundredweight, more care must be taken at portages than in the case
of a canoe, which can be lifted bodily over obstacles. The stems of small
trees, or the oars should be laid down under the boat, and, where possible,
sharp rocks must be avoided or moved out of the way. In a rapid, two
men should be in the bow with poles ]-eady to fend oif from rocks, and
the most experienced man of the crow should be in the stern with the
steer-oar.
Although in the foregoing remarks special reference has been made to
whale-boats, the hints given are equally applicable to boats of other
construction, which should, however, for river work, crossing a bar, or
landing through a surf, be fitted with a steer-oar in addition to the
rudder. Awnings should be taken, but in rapid rivers, and when under
sail, they cannot be used.
MOUNTAIN TRAVEL. 35
Mountain Tkayel. — By Douglas W. Freshfield.
Fresident of the Alpine Club.
The Highlands of Central Asia, and the ranges of western North
America, are among the fields likely next to attract explorers. If their
exploration is to be thorough, travellers must take with them some
knowledge of glacial phenomena. They must learn to know glaciers
and moraines when they see them, to distinguish between ice and neve,
permanent and temporary snowbeds. They must also be able to climb
summits sufficiently high to command the recesses of the chain and the
secrets of the snow world. In order to do this, they must be at the joains
to acquire at least the rudiments of the mountain craft which has been
brought to perfection by three generations of Alpine peasants. Without
these qualifications, even surveyors will find themselves obliged to leave
large and, to tlie physical geographer and geologist, singularly interesting
tracts of country ill-mapped and imperfectly explored, and they will run the
risk of bringing away very erroneous and incomplete impressions of the
phenomena of great mountain chains. The practised mountaineer is free
both from the fears and the rashness of the less experienced traveller, or the
native of the Himalayas, the Andes, or the Caucasus. He is not likely to be
deterred from visiting a remote valley because ice and snow, and possibly
steep and rocky ridges (held impassable by the native hunters), intervene
between him and it ; on the other hand, he will not start on such an
enterprise without every appliance that may enable him to conquer the
difficulties of the way ; he will not walk across a neve without a rope ; he
will not be frightened into retreat by the first crevasse, or stopped by a
hard-frozen slope.
Eopes and ice-axes, procurable at Hill's, 4, Haymarket, are essential. It
is still more essential that their proper use (up to the present time hardly
known outside Europe) should be learnt. This may best be done in an
Alpine tour, with an experienced glacier guide. Travellers without such
experience had best keep to frequented passes, or below the snow-level.
They will be most in danger when they perceive it least, and will imperil
the lives of themselves and their companions. Icecraft, like seaman-
ship, has to be learnt. A party of three is tlie smallest consistent with
safety above the snow-line; and, whatever the number, the majority
D 2
36 HINTS TO TRAVKI.LKllS.
in any expedition of difficulty, sliould be experienced climliers. Such
expeditious will best be mddc from a base where the heavier higgage and
attendants are left.
The best scheme for mountain exploration is one wliich neither limits
the traveller to a single valley or district, nor carries him straight on
from point to point, but allows for various short expeditions from a
succession of centres, at which he can leave his camp and heavy
luggage.
The effect of rarefied air at great heights in reducing the i>ower.<3 of the
human frame is a subject on which precise knowledge is still wanting.
Probably no one has yet closely approached the limit' at which the
exertion of walking uphill becomes imx)Ossible to a person in normal
health and accustomed to great elevations. It lies, therefore, consideral>ly
above 23,000 feet. On the other hand, mountaineers agree that tlieir
powers diminish perceptibly as they ascend above ] 2,000 feet. In l)e
Saussure's generation both he and his guides were, at 15,000 feet, on
Mont Blanc, unable to do more than advance a few yards at a time,
while men of science now spend three days and nights on the summit
of Mont Blanc, and modern climbers feel little or no inconvenience
2000 feet higher on the difficult peaks of the Caucasus, and can still
climb and observe between 22,000 and 23,000 feet in the Karakoram.
Probably up to 18,000 feet the body acclimatizes itself to the uiii:)er
air ; and " training " is therefore one of the best preventives of mountain-
sickness. Chlorate of potash lozenges are said to have been used with
advantage as a palliative. The inconveniences felt on liigh ascents arise
in some part from indigestion, and light but frequent meals (e.r/. soup
at starting, peptonised meat sandwiches and chocolate and cold tea
during the climb) will be found very efficacious in avoiding bodily dis-
comfort. A scientific investigation of the jDrocess by which the human
frame adapts itself to high altitudes has recently been made by M. Yallot.
(See Levasseur's ' Les Alpes,' Paris, 18S9 ; Geographical Journal,
January, 1893 ; and Mr. Conway's forthcoming work on the Karakoram.)
The subject is comjDlex, involving both local and jDersonal conditions,
and demands further experiment and research; all dogmatic statements
must at present be received with reserve.
Next to the rarity of the air frostbite is the most formidable enemy
of the climber who attempts great altitudes. Satisfactory foot-gear has
MOUNTAIN TEAVEL. 37
not yet been devised. Some modification of Arctic expedients suitable
for rock-climbing is ^vanted. The feet must not be compressed and the
circulation impeded. Generally foreign mountaineers jiaj more attention
than Englishmen to climbing-shoes and crampons. The ordinary hob-
nail is good enough for most places where an explorer ought to go, but
crampons may undoubtedly often enable their wearers to reach a point
which would be unattainable to them by stepcutting. They can be
obtained of the Albion Iron and Wirework Co., Eed Lion Street, E.C.
The straps should be of hempwebbing, not leather, f inch wide, to be
obtained at Buckingham's.
The siDecial requisites for snow and ice expeditions are included in
Mr. Whymper's List. His tent, alpine sleeping bags, snow spectacles, felt-
covered water-bottles, self-cooking souptins, chocolate, warm covering
for hands and feet, strongly nailed and easy boots, cloth gaiters, soap-cerate
plaister, Lloyd's cold cream for sunblistering, are among the chief
requisites for high exploration. Take plenty of spare dark glasses for
use by porters in crossing snow passes. Field-glasses are much appre^
ciated as presents by most mountain people, and spare ones should be
taken.
Lirectious as to the observations, which may easily and profitably be
made with regard to the present and past nature and extent of glacial
action, the rate of movement of glaciers and the advance or retreat of
their extremities, the snow- level, the extent and limit of forests and plants
in mountain districts, and the relations of ranges to winds, rainfall, and
climate, will be found in subsequent sections. (See p. 394.)
General information on many subjects, both scientific and practical,
connected with mountaineering, is given in a compact form by the late
Mr. John Ball in his Introduction to 'The Alpne Guide,' published
separately by Messrs. Longmans (2s. 6(/.), or, of more recent date, in the
" Introductory Sections " to Murray's 'Switzerland' (Edition 1892), and
the Badminton Volume on Mountaineering (1892), edited by Mr. Clinton
Dent. The last-mentioned book should be studied carefully by any
traveller proposing to himself serious mountain exploration. He will
find a special chapter from my pen devoted to ' Mountaineering beyond
the Alps.'
( 38 )
OETHOGEAPHY OF GEOGRAPHICAL NAMES.
In 1885 the Council of tlie E.G.S., impressed with the necessity of
endeavouring to reduce the confusion existing in British maps with
regard to the spelling of geographical names, in consequence of the variety
of systems of orthography used by travellers and others to rei)resent
the sound of native place-names in different parts of the world, formally
adopted the general principle which had been long used by many, and
the recognition of which had been steadily gaining gi'ound, viz. that in
writing geographical native names vowels should have their Italian
significance and consonants that which they have in the English language.
This broad principle required elucidation in its details, and a system
based upon it was consequently drawn up with the intention of repre-
senting the principal syllabic sounds.
It will be evident to all who consider the subject, that to ensure a fairly
correct pronunciation of geographical names by an EngUsh-speaking
person an arbitrary system of orthograjjhy is a necessity. It is hardly
too much to say that in the English language every possible combination
of letters has more than one possible pronunciation. A strange word, or
name, even in our own language is frequently niisijronounced. How
much more with words of languages utterly unknown to the reader.
The same necessity does not arise in most continental languages. In
them a definite combination of letters indicates a definite sound, and
each nation consequently has spelt foreign words in accordance with the
orthographic rules of its own language.
It was therefore not anticipated that foreign nations would effect any
change in the form of orthography used in their maps, and the needs of
the English-speaking communities were alone considered.
The object aimed at was to provide a system which should be simple
enough for any educated person to master with the minimum of trouble,
and which at the same time would afford an approximation to the sound
of a place-name such as a native might recognise. No attempt was made
to represent the numberless delicate inflexions of soiuid and tone which
belong to every language, often to different dialects of the same language-
For it was felt not only tliat such a task would be impossible, but that an
attempt to provide for such niceties would defeat the object.
ORTBtOGRAPHY OP GEOGRAPHICAL NAMES. S9
The adoption by others of the system thus settled has been more
general than the Council ventured to hope.
The charts and maps issued by the Admiralty and War Office, have
been, since 1885, compiled and extensively revised in accordance with it.
The Foreign and Colonial Offices have accei^ted it, and the latter has
communicated with the Colonies requesting them to carry it out in respect
to names of native origin.
Even more important, however, than these adhesions is the recent
action of the Government of the United States of America, which, after
an exhaustive enquiry, has adojited a system in close conformity with
that of tlie E.G.S., and has directed that the spelling of all names in their
vast territories shoixld, in cases where the orthography is at present
doubtful, be settled autlioritatively by a Committee appointed for the
purpose.
The two great English-speaking nations arc thus working in harmony.
Contrary to expectation, but highly satisfactory, is the news that
France and Germany have both formuhited systems of orthography for
foreign words, which in many details agree with the English system.
The Council of the K.G.S., by printing the Kules in 'Hints to
Travellers,' and by other means, have endeavoured to ensure that all
travellers connected with the Society should be made aware of them.
To this end, and with a view to still closer uniformity in geograj^liical
nomenclature in revisions of editions of published maps, a gigantic task,
requiring many years to carry out, the Council have decided to take steps
to commence tentatively indexes of a few regions, in which the place-
names will be recorded in the accepted form.
EULES.
The Eules referred to are as follows : —
1. No change is made in the orthography of foreign names in countries
which use Eoman letters : thus, Spanish, Portuguese, Dutch, &c., names
will be spelt as by the respective nations.
2. Neither is change made in the spelling of such names in languages
which are not written in Eoman character as have become by long usage
familiar to English readers : thus Calcutta, Cutch, Celebes, Mecca, &c.,
will be retained in their present form.
40 HIN'i'S TO TKAVKLLKl.'S.
3. Tlicj true huaud of the word as locally jirououiiced will l)C taken as
the basis of the spelling.
4. All approximation, liowever, to tlio sound is alone aimed at. A
system which -would attempt to represent the more delicate inflexions of
sound and accent would be so complicated as only to defeat itself. Those
who desire a more accurate ])ronunciation of the written name must
learn it on the spot by a study of local accent and peoiliarities.
5. The hrou'l features of the aijufera are : —
(rt) That vowels arc pronounced as in Italian and consonants as
in English.
(i) Every letter is pronounced, and no redundant letters arc in-
troduced. When two vowels come together, eaclj one is sounded
though the result, when spoken quickly, is sometimes scarcely
to be distinguished from a single sound, as in ai, au, ei.
(c) One accent only is used, the acute, to denote the syllable on
which stress is laid. This is very important, as the sounds
of many names are entirely altered by the misplacement of this
" stress."
6. Indian names are accei)ted as spelt in ' Hunter's Gazetteer of India,'
1881.
7. lu the case of native names in countries under the dominion of
other European Powers in whose maps, charts, &c., the spelling is given
according to the system adopted by that Power, such orthography should
be as a rule disregarded, and the names spelt according to the Briti.sh
system, in order that the proper pronunciation may be approximately
known. Exceptions should be in cases where the spelling has become by
custom fixed, and occasionally it may be desirable to give both forms.
8. Generic geograjihical terms, e.g. those for Island, Eiver, Mountain,
&c., should be as a rule given in the native form. In the case of Euro-
pean countries, translation into English, where this has been the custom,
should be retained, e.g., Capn Ortegal, not Cabo Ortegal, Piiver Seine, not
Fleuve Seine.
N.B. — On any i)riDted map or MS. document, an explanatory table
giving the English equivalents of the generic term.s used, should of
necessity be inserti'd.
ORTHOGHAPHY OP GEOGRAPHICAL NAMES. 41
The following amplification of these rules explains their application : —
Pronunciation and Remarks.
Examples.
au
ao
aw
ch
d
f
g
li
hw
ah, a as m father
eh, a. as \nfate ..
English e; i as in ravine; the sound of
ee in heet. Thus, not Feejee, but
as in mote
long u as in flute ; the sound of oo in hoot.
00 or oil: should never be employed for
this sound . . Thus, not Zooloo, but
All vowels arc shortened in sound hy
doidiliiKj the follow! iig consonant.
Doubling of a vowel is only necessary
where there is a distinct repetition of
the single sound,
as in aisle, or English i as in ice ..
ow as in Itoio Thus, not Foochow, but
is slightly ditferent from above
when followed by a consonant or at the
end of a word, as in laio
is the sound uf the two Italian vowels,
but is frequently slurred over, when it
is scarcely to be distinguished li'om ei
in the English eight or ey in the English
they.
English h.
is always soft, but is so nearly the sound
of s that it should be seldom used.
If Celebes were not already recognised it
would be written Selehes.
is always soft as in church
English d,
English /. ph should not be used for the
sound of/. Thus, not Haiphong, but
is always hard. (Soft g is given hy J) . .
is always pronounced when inserted.
as in uhat ; better rendered by Inn than
by 'wli, or h followed by a vowel, thus
Uivang lio, not Wltang ho, or Tloang ho.
Java, Banana, Somali, Bari.
Tel-el-Kebir, Ole'leh, Yezo,
Medina, Levuka, Peru.
Fiji, Hindi.
Tokyo.
Zidu, Sumatra.
Yarra, Tanna, Mecca, Jidda,
Bonny.*
Nuulua, Oosima.
Shanghai.
Fuchau.
Macao.
Cawnpore.
Beirut, Beilul.
Cele'bes.
Chingchin.
Haifong, Nafa.
Galapagos.
Hwang ho, Ngan hwi.
* The 1/ is retained as a terminal in this word under Rule 2 above. The word is given as a
familiar example of the alteration in sound caused by the second consonant.
42
HINTS TO TRAVELLERS.
Letters.
J
k
kh
gh
1
m
n
ng
P
ph.
th
rionuiiciatiuii mid Kcmaiks.
Kxaiiij.k-B.
8h
t
zh
English > Dj sliould never be imt for Japan, Jinchuen.
. this sound.
English /•;. It shoulil always be put for
the hard c. Tlius, not Corea, but Korea.
The Oriental guttural Khan.
is another guttural, as in Uie Turkisli .. Dagh, Gliazi.
As in English.
has two separate sounds, the one hard as
in the English word finger, tlie other
as in singer. As these two sounds are
rarely employed in the same locality,
no attempt is made to distinguish
between them.
As in English.
As in loophole : Chemulplio, Mokpho.
stands both for its sound in thing, and as Bethlehem.
in this. The former is most common,
should never be employed ; qu (in quiver) Kwaugtuug.
is given as hw. I
When qu has the sound of h as in quoit,
it should be given by A-.
\
}-As in English,
Sawiikiu.
Kikiiyu.
is always a consonant, as iu yard, and
therefore sliould never be used as a
terminal, i or e being substituted as the
sound may require.
Thus, not Mikinduiiy, wady, but
not Kmdy, but
English 2 Zulu.
Mikiudilui, wadi.
Kwule.
The French J, or as s in treasure.
Accents should not generally be used,
but where there is a very decided
emphatic syllable or stress, which
aft'ects the sound of the word, it should
be marked by an acute accent.
Muzlidaha.
Tougatabu, Galapagos
Palawan, Sarawak.
ORTHOGKAPHY OF GEOGRAPHICAL NAMES.
43
Table of Sound Equivalents adopted for the Tkansliteeation of Geo-
GRAPHICAL Names by Great Britain, United States, France, Germany,
AND Spain.
au
ao
ei
b
c
ch
d
f
g
li
.1
k
kh
gh
1
m
n
ng
P
ph
kw
r
s
t
V
Great Britain.
as in father
as in henkfit ..
as in ravine ..
as in mote
as in flute
as i in ice
as ow in how ..
as in Macao ..
as in eight
as in Engli.sh . .
soft
as in church ..
English d .. . .
„ / .. ..
hard g
always aspirated . .
English /
„ h
Oriental guttural . .
English I
„ 711 .. ..
,, u
as in finger and singer
English p
as in loophole ..
English qv, in quiver
English ;•
,, s
t
,, V
„ w ....
_„ a; .. ..
as in yard
English 2
au
ao
ei
6
ii
b
c
ch
d
.1
k
kh
gli
1
P
ph
kw
c
S
CD
CO
a a
a
e
e
i
i
u
u
or tch
d
f
It
h
urdj
k
kh
gh
I
lu
ai
au
ao
tsh
d
f
g
h
k
kh
s;h
^1
ch
d
f
g
h
y
k 41
p
p
kw
qu
r
r
s
s
t
t
V
V
As ill I'lx'ucli
( 44 )
III.
MEDIOAL AND SUEGIOAL HINTS.
By Surgn.-Majok Thos. Heazle Parkk, Hox. D.C.L., Hon.
F.E.C.S.L, &c.*
1. Pebsonal Care of Health.
It is very desiniblo that persons who are thinking of traveUiug or
residing in troi)ical climates should be sure that their physique warrants
the venture before making a change from the temperate residences of the
northern or southern hemisi)heres. Persons of good constitution and
regiilar and temperate habits can, undoubtedly, with judicious care
maintain a fair state of health in the tropics. And even those who have
been by no means very strong at home can with some extra care do very
well in most joarts of even the hottest climates, if peculiar circumstances
make the change otherwise very desirable. All immigrants to hot
climates should be instructed in certain invariable rules, deviation from
which is always accompanied by more or less risk.
The surface of the body should, as far as possible, be kept at an equable
temperature. On account of their non-conducting properties, the under
garments should be of wool, or a mixtiire of silk and wool, which is lighter.
As is well known, wool owes its non-conducting property to the tortuosity
of its fibres. All woollen garments, on this account, and especially the
looser ones, contain a large quantity of imprisoned aii-, which is the real
non-conductor. For the same reason, two or more fine woollen shirts
will be found much more efficient than a single coarse one, on account of
the layer of air retained between. The fine flannel shirts are, accordingly,
to be preferred, because the number worn can be so easily adjusted to
varying temperatiires ; and it is obviously much better on that account
to be provided with a large number of them, than a small number of
Tbid suctiuii WHS propurud shortlj' before the writer's premature death.
MEDICAL AND SUKGICAL HINTS. 45
thick aud heavy ones. Sleeves can be dispensed with in the great
majority of the number; when several shirts are worn, one only should be
provided with sleeves. In regions where the temperature of the night
diifers but little from that of the day, a fine flannel shirt should be worn
next the skin, while the rest of the body and limbs may be protected with
any thin cotton or linen fabric. On the other hand, in the neighbourhood
of mountain ranges, or on high table lauds, when the diurnal range of
temperature is very considerable, care must be taken, either to wear a
complete woollen suit at all times, or to change before sunset. Sodden
chill is, in the exjDerience of the present writer, the most fertile source of
tropical fever.
Night clothes (pj'jamas) should consist of an India flannel shirt, opening
down the front, and secured with linen buttons or with tapes; and a
long, wide pair of trousers of the same material, provided with feet to
keep out insects, which can be conveniently drawn together by a running
string. In very warm regions, the latter garment may be of silk.
All flannel textures should be of wool throughout, and made to fit /•<.-, •?/
loosely, as they necessarily shrink in washing.
Other garments which will be found useful are : lined and pei'forated
chamois-leather under-vests, which are excellent protection against cold,
penetrating breezes ; long woollen comforters, and a long, wide silk scarf for
winding around the waist. The latter is often used in very hot climates,
with a roomy woollen shirt next the skin — fitting loosely around the
neck, and reaching only to the hips — and a thin linen or calico trousers.
The scarf (Kamarband) is then swathed around the abdomen and loins in
two or three folds. In the majority of instances, a fine flannel shirt,
short, thin, loose calico drawers, a loose fitting Norfolk jacket buttoned
to the throat, and a pair of thin serge trousers or knickerbockers, will be
found to form a very eligible tropical suit ; gaiters or putties protect the
shin if necessary.
The head and spine should be prote.ted with great care.
A well-fitting ventilated pith helmet forms an excellent protection
against the vertical rays of tlie mid-day sun ; the more oblique rays of
morning and evening are shaded off by tlie use of a curtain descending
from the rim of the helmet. It can be folded up around the helmet, or
46 HINTS TO TRAVELLEES.
removed during the middle period of the day, if more convenient. A
woollen spinal pad is absolutely necessary to protect the spinal cord from
the tropical sun. A white or green covered umbrella is also indispensable
to the troi")ical traveller.
The aa-my regulation helmet is the best known design.
Avoid chills, drart(ihts, and wettiufjs.
Wlicn on board ship, sleeping opposite open ports or under a wind
sail, is often followed by fever. At the time of landing, too, there is great
danger from the effects of the sudden change from the warm sea breeze
to the cold land breeze in the evening. I am convinced that a great deal
of the fever which gives many tropical coasts so bad a name among
European travellers might be avoided by having regard to this pre-
caution. On ai^proaching land, the traveller is very usually tempted, on
coming up from the almost Turkish-bath temperature of the saloon,
where he has been lolling about in the minimum quantity of dress, to
stand for some time on deck to enjoy this refreshing breeze. A large
proportion of the worst cases of tropical fever, dysentery, rheumatism,
and pleuro-pneumonic affections are ushered in in this way. Sleeping on
deck should be avoided. Evening chills are also a prominent factor
in the causation of disease in tropical highlands, where the fall of
temperature is usually very considerable. Also, in marching through
hilly districts of sub-tropical regions, where the ascent of an eminence is
necessarily attended by profuse perspiration, and the summit furnishes
the chilly breeze which rapidly checks it; the consequent dull, which the
work of descent is not sufficient to check, is very generally followed by
fever.
In crossing Equatorial Africa, the members of the Emin Pasha Relief
Expedition found that every v.-etting meant an attack offerer. The frequent
wading of streams was one of the prominent and oft-repeated difficulties
to be encountered; every such operation was followed by an attack of
fever — to man and beast alike! A drenching tropical shower had the
same effect. It need hardly be added that sitting in damp clothes should
be avoided.
On completing a day's journey — with or without a wetting — theimder-
clothing, at least, should be changed without a moment's delay.
MEDICAL AND SURGICAL HINTS. 47
Use of mosquito curtains.
The use of protective coverings against the attacks of this troj^ical jiest
is a consideration which cannot be too strongly impressed upon the in-
tending traveller. A well-prepared mosquito curtain will, of course, also
protect the person from the attacks of other troublesome insects. The
"Tuckett Insect-Pazzler," which has been described and figured on
page 22 (see Hints), will be found a thoroughly efficacious form of pro-
tection against the troublesome invasions of insects in general. The
traveller should also provide himself with mosquito netting, with which
he can envelop himself, if obliged to dispense with the carriage of any
elaborate apparatus. A protective covering can then be always impro-
vised by taking a piece of netting, about seven yards long by four wide,
the extremities of which should then be carefully united so as to form
a cylinder. One of these may be bound with calico, and furnished with
a running string; the other should be fastened up and confined by a
tightly strained copper wire fastened in a groove let into the outer margin
of a circular piece of flat deal board, about one foot in diameter ; to the
centre of this board the end of a strong coil of cord is fixed. Such
curtains can always be fixed in i^osition at a moment's notice, whenever
the traveller's bed or hammock has to be arranged for the night. The
long cord may be thrown over the cross-tie of a rafter of a hut, over
a branch of a tree, or be hitched to the pole of a tent, carrying with
it to any desired height the circular piece of board which siipports the
curtain, and tiae latter may then be spread over the bed and tucked
beneath it, or secured with a running string if necessary.
It has been said that the mosquito curtain will also be found pro-
tective against the malarial poison, but of this I am not at all convinced.
Apart from saving the traveller from immediate annoyance, the careful
use of the mosquito curtain is also preventive of the remoter evil of the
introduction of the hilharzia haemntohia into the circulation, with the
resulting evils of heematuria and anaemia.
Smoke of any kind keeps away insects, particularly when due to
burning cow-dung.
48 HINTS TO TRAVELT.ERS.
In malarious diMrirts, the poison is more concentrah d at nigJU than during
the day — on this riccomd nocturnal expoKxrc s/u/td'l lie aroid<d as much as
2>ossihle,
Old asttlers ou tlie West African coast have lon^ recognised the danger
of venturing ont of dooi's when the sun is not above tlie horizon. In the
malarious districts of Italy, travellers find the danger of going about at
night. The hours immediately preceding sunrise are found to be the
most dangerous. The evident cause is, that the malarious vapours which
certainly alv/ays prefer low altitudes, although not absolutely confined
to them, are more concentrated at this period. They have a tendency
to keep close to the level of the soil ; they are carried upwards by the
ascent of the water-vapour during the day, and the condensation accom-
panying the cold of night carries them down to earth again. Accordingly,
the poison is more concentrated during the night. Dependent on this is
the fact, often learned l)y travellers in Italian hotels, that it is safer to
sleep at night in a top stoiy tliau in a lower one; and that when one is
obliged to travel at night it is miich better to travel on the top of the
diligence than inside.
Immersion in cold ivater is to he ai'uided as much as possible in hot climates.
It has already been mentioned that wading a river or exposure to a
drenching shower in Equatorial Africa is almost invariably followed by
fever— the same holds true even of a prolonged cold bath. Accordingly,
the rule for bathing should be that the water must not be quite cold,
and that the immersion should be short, and followed by a rapid and
vigorous rubbing with rough towels. In the case of persons who have
already siiffered from many attacks of fever, or from dysentery, or con-
gestion or other disease of the liver, or any otlier of the important viscera,
warm bathing should alone be used. Bathing should never be resorted
to during the process of digestion.
Whenever an accidental drenching from a tropical shower occurs, or
that the traveller has waded, or been accidentally immersed in, a stream
or an arm of a lake, he should, as soon as possible, remove all clothing
and be thoroughly dried with rough towels. Not only fevers, but the
introduction of parasites into the integument, is often a consequence of a
plunge into tropical waters.
MEDICAL AND SURGICAL HINTS. 49
The quantity and quality of food and of drink slioidd he carefully regulated.
The lassitude which is often so mvich felt by European residents within
the tropics too frequently tempts them to the abuse of alcoholic stimu-
lants and of highly-spiced food, as a means of getting rid of such feelings
for the time being. The habit is a most pernicious one, and all induce-
ments in that direction should be resisted from the beginning. Such
indulgence is one of the most fruitful causes of the permanent ill-health,
which is so often wrongly attributed to the mere residence in the hot
climate. There is no doubt that food should be used with greater
moderation in hot than in cold climates. Heat-producing articles of
diet, such as fats, should be taken in far smaller quantity. The meals
should never be heavy — especially diiring the heat of the day, when the
serious mistake of indulging in very liberal luncheons is far too frequently
made. Sufficient intervals of time should always separate consecutive
meals; even in temperate climes a space of at least five hours should
always be allowed between meals, and in trojDical regions the period
should be increased.
So long as the general health continues to be fairly well preserved,
there is no doubt that any over-indulgence in the use of alcoholic stimu-
lants is one of the most fatal errors into which the tropical resident can
fall. When not over-worked, or suffering from the prostration consequent
upon fever or other illness, hot coffee, tea or cocoa will nearly always be
found sufficiently refreshing. But, on the other hand, it miist be laid
down with corresponding emphasis, that a supply of alcoholic stimulants
is one of the most important additions to the traveller's outfit. "When
exhausted by the fever from which the European resident in the tropics
is pretty sure to suffer at one time or many, there is no doubt tliat the
judicious use of stimulants is of all means the most essential in appli-
cation, and the most efficacious in results. It is not merely that the
immediate use may make all the difference between life and death at the
time, but may save a constitution from being permanently broken. But
in order that these good effects may be obtained in the time of need, it is
necessary that the use of alcoholic stimulants should be medicinal, and
never looked upon as an ordinary adjunct to the essential dietary. When
a course of continued physical or mental exertion has to be maintained
for a considerable time, there is no doubt that the use of alcohol in
E
50 HINTS TO TRAVELLERS.
.moderation is highly essential. Of the multitudinous forms in which
it is used at home, tlie purer specimens of whisky and brandy are
decidedly to be preferred, and they should always be well diluted.
Champagne will also be always found a grateful and a beneficial
beverage to the exhausted traveller. On the other hand, the uncon-
centrated alcoholic preparations, such as beer, porter, claret, &c. will
be found to give much less satisfactory results; they are much more
highly provocative of gastro-intestinal and hepatic derangements ; and
are, of course, less easily obtained of really good quality.
The cooking should always be conducted with gTeat care in the tropics ;
the stomach and liver are less able to bear any extra strain, such as
would be induced by the attempted digestion of imperfectly cooked food.
Besides, parasites are often introduced with ill-prepared articles of diet.
The use of drinlcinr] water must be attended to with great care in all
tropical climates. The surrounding luxuriance of animal and vegetable
life, which so usually prevails, generally furnishes the water with a larger
proportion of impurities than are to be found in corresponding i:)Ositions
in temperate climates, and the accompanying factor of high temperature
promotes all sorts of fermentation and moleciilar decomi^osition in its
chemical constituents. Accordingly, the water of the lakes, streams, and
pools of hot countries are extremely impure, and contain the seeds of all
kinds of gastro-intestinal diseases. On this accoiuit, all water should be
filtered and boiled before being used for drinking or cooking purposes.
The drinking of very cold water, to which there is often great temptation
when one is exhausted by prolonged heat and copious perspiration, should
be most carefully avoided. The feeling referred to often induces trojiical
residents to have recourse to wed water, which is always extremely
dangerous under such circumstances. The use of copious draughts of
water is also a habit to be deprecated : it certainly weakens the muscular
energy, and is always rapidly lost by perspiration, which tends to increase
the feeling of exhaustion. Hot or cold tea, without milk or sugar, is
usually one of the most grateful, and least injurious, of the beverages
which can be used by the tropical resident when working or journeying
under a hot sun.
In this connexion it should also be remembered that the jirocess of
freezing by no means destroys all the pathogenic microbes, so that the
fact that the water to be used has been procured by the thawing of ice
MEDICAL AND SUEGIOAL HINTS. 51
by no means guarantees its freedom from disease-producing agents, as
many otherwise well-informed persons seem to think. Also, that in other
parts of the world, as well as in the tropics, it is often very necessary to
use all the above precautions with regard to drinkiug water on entering
an unknown district.
It is hardly necessary to observe that travellers in remote regions, and
more especially in tropical climates, are much more exposed to physical
ills and diseases than most residents at home, and that they are also more
likely to be placed beyond the reach of skilled medical and surgical aid
when the latter may be most required. It is especially for the use of the
non-professional traveller that the following pages have been written, in
which the symptoms and general treatment of the diseases and injuries
from which he is most likely to suffer are dealt with in simple, non-
technical language.
In recommending the medicinal remedies with which the traveller
should be provided before leaving home, I have chosen throughout the
tabloid preparations of the well-known firm of Messrs. Burroughs,
Wellcome, & Co., as I have found, after a very considerable experience of
tropical travel and exposure, which form the very severest tests of the
reliability of medicines, that they are the best I know of in constancy and
unchangeability of strength, as well as in their extreme portability for
purposes of transit.
A. — Medical Diseases.
Cold in the head (coryza), inflammation of the upper part of the wind-
pipe — the organ of voice or larynx (laryngitis), iiflammation of the branches
if the wind-pipe (bronchitis), inflammation of the lung (jmeumonia), and in-
flammation of the investing membrane of this organ — the pleura (pleuritis),
raay be conveniently considered together, forming, as they do, a con-
tinuous group of ailments due to exposure to chill, and affecting, as they
do, the various sections of the organs of respiration according to the
degree of exposure, the general susceptibility of the patient, or the special
vulnerability of the organ attacked. When a cold is confined to the head,
it can usually be cut short by retiring to bed early, taking a ten-grain
dose of Dover's powder (two five-grain tabloids), with hot drinks to pro-
mote the perspiration which the action of this drug produces, and the use
E 2
62 HINTS TO TRAVELLERS.
of as many additional bed-clothes as can Itc conveniently borne. Care
should, of course, be taken to avoid chill on the following morning. In
tropical regions, five grains of quinine (bisiilphate tabloid) may be added
with advantage to the ordinary dose of Dover's powder.
Whcii the wind-pipe is affected, there is hoarseness of voice, cough,
pain in swallowing, and tenderness on pressure over the region of Adam's
apple. A similar treatment may be adopted, in addition to which the
upper i^art of the front of the throat sliould be kept well poulticed for a
day or two, and then wrapped up in cotton wool for some days longer.
When bronchitis exists, there is a good deal of coughing — at first dry,
and afterwards accompanied by frothy expectoration — with a sensation of
rawness and tenderness at the upper part of the breast-bone. In the
early stage of tliis condition, half tea-spoonful doses of paregoric elixir
(two fifteen-min. tabloids of tinct. camph. co.) will be found very bene-
ficial. The opium tinct. tabloids, of which two to four may be taken every
half-hour, will be found an excellent remedy during the first day of the
development of bronchitis, and w'ill often effectually cut short an attack.
As even what would appear to be ordinary feverish colds have, in
tropical climates, very often a tendency to become intermittent, the use
of quinine in addition to the other treatment employed is often very
desirable. The tabloids of quinine bisulph., which contain five grains
each, can be taken every third hour with the best result.
Fneumonia is always ushered in by severe and prolonged shivering,
during which the temperature rises rapidly, and the pulse and respiration
are greatly quickened. The face is flushed, the skin feels very hot and
peculiarly dry, the patient is prostrated by heavy sickness, and there is a
short cough, dry at first, but afterw'ards there is expectoration of a
moderate quantity of viscid, rust-coloured (blood-stained), and almost
frothless matter.
A patient attacked with pneumonia should take to bed at once. The
chest should be surrounded with a large poultice on the affected side. If
the fever is very high, with great restlessness and rapidity of breathing,
bleeding often gives moi-e relief than any other treatment. Quinine is
decidedly beneficial, a five-grain tabloid of the bisulphate should be
given every third hour; in cases where other complications exist, a
tabloid of digitalis tinct. should be given every hour for one or two days
when the temperature is very high.
MEDICAL AND SURGICAL HINTS. 53
Pleurisy is accompanied by a more moderate degree of fever and
general sickness than pneumonia ; its great characteristic symptom is tlie
" stitch in the side " which always accompanies it. It is also accompanied
by a short, dry cough, which the patient tries to restrain as it " catches "
in the side, and causes very acute pain. For the same reason the
respiration is shallow, as any attempt to draw a deep breath causes
extreme suffering.
This is more a disease of cold climates; it is very usually the result of
chill following severe exertion. The patient suffers greatly, and, on that
account, the most important symjitom in the early stage of the disease is
the pain. If leeches are procurable, the aiiplication of half-a-dozen to
the painful region of the chest is always an excellent remedy. After
this, five tabloids of the opium tincture should be taken every hour.
The movements of the chest during respiration should be checked by
carefully-applied adhesive plaster or bandage.
Bheumatism is another disease which very frequently follows exposure
to damp cold, and is on that account not so frequent in the tropics as in
temperate and cold climates. A decided predisposition to this affection
is generally traceable in the persons attacked. It is very often hereditary,
and tends to recur in the same individual. On that account it is very
necessary that persons with a tendency to this disease should use special
precautions. The acute cases are ushered in by shivering, with rise of
temperature, and general sickness; while the joints become painful,
tender, and afterwards swollen. It agrees with other feverish conditions
in the rapid pulse and resiDiration, constipation, scanty and high-coloured
urine, etc., but it differs from most of them in the j^resence of a profuse
and highly acid perspiration, which gives the patient a very characteristic
buttermilk-like smell.
The great remedy for acute rheumatism is soda salicylate. Four of the
five-gi'ain tabloids of soda salicylate should be taken every third hour.
This will nearly always correct the acute symptoms in two or three days.
If the symptoms subside sooner, the quantity of the drug should be
diminished ; if there is a pronounced tendency to delirium the quantity
should also be lessened at once. The joints should, at the same time, be
kept completely wrapped up in cotton wool, secured with oiled silk and
tiannel bandages.
54 HINTS TO TRAVELLEKP.
Colic.
This is the name given to the well-known severe twisting or griping
IDains in the abdomen, usually due to iiTcgular development of gas
within tlie intestine, and dependent on constipation or the unhealthy
fermentation of some ill-chosen article of diet. Hot turpentine fomenta-
tions should be applied to the abdomen, and a turpentine enema will
nearly always cut short the symptoms. A full dose of opium should also
be given.
Constipation.
This condition is very frequent in tropical climates, where it is asso-
ciated with torpidity of the liver. It is also very generally met with on
board ship. One of the best remedies is the tabloid of cascara comp., of
which one may be taken three times a day. In addition to this an
occasional dose of a saline purge should always be used, or a large enema
of soap and water.
Dysentery.
This disease is essentially a specific inflammation of the lining
membrane of the lower segment of the bow^el, with a tendency to ulcera-
tion. The more severe cases are accompanied by extreme congestion of
the liver, which often proceeds to the formation of deep-seated abscess.
The most potent causes are bad and insufiBcient food, impure water, and
prolonged cliills. General debility and mental anxiety are predisposing
causes; and, accordingly, it has frequently proved one of the most
terrible scourges of retreating armies.
The disease may, or may not, be ushered in by diarrhoea. The most
characteristic symi^tom in the early stage is the sensation of burning
heat and darting pain in the vicinity of the lower orifice of the bowel.
This gives rise to the sensation of desire to strain, which continually
distresses the patient. The discharge from the bowel at first consists
chiefly of gelatinous mucus, which afterwards becomes blood-stained.
In bad cases, large quantities of blood are discharged, and even shreds of
the mucous membrane of the bowel are detached by ulceration or
sloughing, and are passed by stool — giving the evacuation a veiy offensive
MEDICAL AND SURGICAL HINTS. 55
and characteristic odour of decomjiosing flesh. In addition to this the
patient suffers from irregular shooting and griping pains in the abdomen,
which is also very tender on pressure.
Ipecacuanha is the specific remedy for acute dysentery. It should be
given in very large doses, fifteen to thirty grains (three to six of the five-
grain tabloids). The aiDplication of a hot poultice to pit of the stomach will
often prevent its being brought up again, which it is, otherwise, of course,
likely to be. Sometimes opium acts as an eifectual corrective to the
nausea ; so that it will be found that the " Dover's Powder " tabloids
will be retained when the others will not be. The dose should be
repeated at an interval of about six hours. The abdomen should always
be kept covered with poultices as liot as can be borne. Boiled milk
and arrowroot, or i^lantain flour, will form the safest diet during the
acute stage. It should be remembered, too, that attention to the diet
is of the last importance in this disease. Animal broths should only
bo used with great caution, if at all. When the dysentery is compli-
cated with malaria, as it very often is in the tropics, quinine should
also be given — large doses will often be well borne (three of the five-
grain tabloids of quinine bisulphate).
Fever.
The peculiar fevers from which travellers are likely to suffer arc more
especially those of the type generally known as malarial. I don't jiropose
to discuss the nature of the specific poison which produces these fevers.
Two broad divisions of malarial fever are generally recognised : the uiter-
■mitfent, and the remittent. The former is poj^ularly known as ague, and
is characterised by the recurrence of definite periods of complete absence
of the elevation of temperature. The latter presents well-marked sub-
sidences of temperature; which, however, never descends to the normal
standard till the patient is entering upon the stage of convalescence.
A characteristic attack of ague is ushered in by a feeling of cold running
down the spine, the patient feels general malaise, he seems to shrivel up,
as the superficial blood-vessels all contract, the lips and finger-tij^s become
livid, the hair stands on end ("goose-skin") and severe pains are felt in
the temples and in the loins. During the whole of this stage of apjiarently
violent chilliness the temperature is rapidly rising. As this stage passes
56 HINTS TO TRAVKLLKKS.
off, the superficial blood-vessels dilate; and, as an immediate consequence,
the surface becomes flushed, and the patient feels uncomfortably hd. The
skin is, however, still dry ; but, by-and-by, perspiration commences,
which soon becomes very profuse — constituting the siveatmf/ stage.
During' this latter stage, the temperature gradually falls till it has
reached the normal standard. When the fever has gone, the patient
feels weak and exhausted, with a great deal of muscular soreness. If
the hot stage is much prolonged, a hyjiodermic injection of pilocarpine
gives relief l)y inducing sweating.
The attacks sometimes repeat themselves with the greatest regularity.
The best treatment is the use of large doses of quinine, given a little
before the expected time of attack. The doses which may be borne are
sometimes enormous; the present writer has often taken as much as
60 grains at a single dose. The quinine should never be administered
during the paroxysm of intermittent fever : it never cuts short the attack ;
while, on the other hand, it increases the sickness and distress. The
patient should, of course, have rest in bad cases ; although it is wonderful
to observe how well the aflected person can go about, and do a good deal
of energetic work during an attack of African fever. Every one of the
white ofHcers of the Emin Pasha Belief Expedition had, over and over
again, the exi^erience of going through a hard day's work with a tempera-
ture of between 105° and 106° F., doing 15 or 20 miles march.
A full calomel purge at the beginning of an attack is often very useful.
"Where a sweating stage occurs, it is of course very desirable to prevent
any exposure to chill during, and for some time after, its course. lu bad
cases of remittent fever, it is very desirable that the patient should be
removed, even while the fever is on him, to a higher and drier locality ;
during the early stage of fever a large do.se of oi)ium is invaluable.
In cases of older standing, quinine sometimes appears entirely to fail as
a curative agent. In such cases, arsenical preparations are often extremely
useful. Two of the 1-50 gr. arsenious acid tabloids may be taken every
third hour for a considerable time. It must be remembered that arsenical
prepariitious should never be taken on an empty stomach. Warburg's
tincture is also most useful.
MEDICAL AND SURGICAL HINTS. 57
Affections of the Liver : Congestion, Abscess.
A large proportion of the cases of " liver " which occur in the tropics
are undoubtedly the results of over-stimulation by the excessive use of
hot condiments and alcoholic stimulants. There can be no question,
however, that the malarial poison affects this organ, and that many of the
worst cases are due to its influence; while in every case, the functional
weakness of the organ, induced by the action of this mysterious agency,
renders it more likely to be affected by the action of stimulants and other
agents which would have but a slight deleterious effect had it been in a
previously healthy condition.
Congestion of the liver is indicated by a sensation of fulness and
dragging under the false ribs on the right side ; the organ may, in thin
persons, be felt in this position ; it is somewhat tender on pressure ; there
is sometimes pain referred to the right shoulder ; usually a little jaundice —
most noticeable at the inner corners of the eyes. The patient suffers from
lassitude, indigestion, and a bud taste in the mouth.
"When abscess of the liver exists, the symptoms are sometimes very
obscure indeed ; but in the well-marked cases there will be night-sweats,
wasting, and hectic fever, with its characteristic oscillations of temperature.
If fluctuation is felt draw off the fluid with an " as])irator " or puncture.
Acute congestion of the liver should be treated by hot fomentations,
and the use of calomel and saline purges. The use of ipecacuanha is also
extremely beneficial in acute congestion and inflammation of the organ.
Large doses are indicated : a tive-grain tabloid may be taken every two
hoixrs for the first day, while the pit of the stomach, as well as the surface
over the liver, are kept covered with hot poultices. The patient should
be allowed absolute rest in all very acute cases. The diet should also be
restricted ; vegetable food is the safest.
Night Blindness : Snoiv Blindness.
Night blindness sometimes results from exposure to the glare of the
tropical sun — especially if long continued — in the case of persons debili-
tated by insufficient or bad food. Snow blindness, on the other hand,
follows over-stimulation of the retina by the glare from snow, when the
eyes have been for a long time exposed to it, either in Arctic regions, or at
58
HINTS TO TRAVELLERS.
altitudes above the snow-line in temperate or tropical zones. Of course
the best treatment for all svich cases is the preventive one of wearing
protective spectacles. Travellers in snowy regions shoiald always be
provided with smoked glasses ; if these happen to get broken or lost,
some opaque substance may be smeared over the surface of an ordinary
pair, having a narrow horizontal slit of clear glass — in the Esquimaux
fashion, shown in the accompanying illustration. On snow it must
ct^
be remembered that the perforated wire gauze sidt-s are essential for jiro-
tection from the refracted sun's rays. Elastic may be substituted with
advantage for the ordinary metallic attachments, between the glasses as
well as around the head. In the tropics a veil is sometimes attached to
the glasses, and can be worn as a protection from insects and from the
blistering of the face which is produced by the sun's heat. Blackening
the skin around the eyes, and the adjacent part of the nose, is a good deal
employed by natives of high mountain regions in some parts of the world
as a preventive treatment of snow blindness ; but it is, as will easily be
surmised, a very ineflScacious one.
Ophthalmia.
Ophthalmia, or conjunctivitis, is inflammation of the membrane which
covers the front of the eye-ball and the deep surface of the eye-lid. It is
MEDICAL AND SURGICAL HINTS. 59
characterised by gritty pain, i.e. a feeling as if sand or dust had got under
the eye-lid ; the affected eye is " blood-shot," and exposure to strong light
is intolerable. The eye waters profusely. When severe, it is accompanied
by a certain amount of headache, and even general fever. It is often due
to cold draughts of air, also to the particles of sand which are always
getting into the eyes in sandy regions (as in tropical deserts). It is also
produced by the irritation of flies, which swarm in legions about the
traveller during so much of his tropical wanderings ; and, as the worse
forms are undoubtedly highly contagious, flies carry about the germs of
the disease from eye to eye.
Careful washing of the eyes, and subsequent application of a solution
of borax, cocaine, or zinc, or the use of atropine discs, will be found a
satisfactory treatment if the disease has not been too long neglected. In
chronic cases skilled assistance will be necessary.
Piles.
This troublesome affection is common in tropical climates, dependent,
as it so usually is, on some sluggishness or arrest of the circulation within
the liver. Piles are dilatations of the veins in the neighbourhood of tlie
orifice of the lower bowel. These enlargements form painful tumours,
which are situated sometimes within, sometimes without, the orifice, and,
on that account, are usually distinguished as internal and external. The
former usually give rise to the more serious symptoms, as they often
bleed profusely, and leave the patient very weak and anaemic. Both
kinds are accompanied by sensations of heat and painful fulness in the
part, which are aggravated by movements of every kind. Their early
formation is promoted by sedentary habits, and neglect of the bowels.
When the piles are inflamed and acutely painful, leeching is one of the
best methods of palliation. The bowels should always be kept free while
piles exist ; but violent jjurging must be avoided, as the consequent irri-
tation and straining will cause increased growth of the piles, and an
increase of the distressing symptoms accompanying them. In piles of old
standing, surgical operation by a competent hand will be found necessary.
When relieved by treatment, the patient should study to prevent their
recurrence by keeping the bowels extremely regular, taking a fair amount
of open-air exercise, and general regular living, with cold water ablution
frequently.
Co HINTS TO TKAVKI.MOkS.
Prickly-heat.
Tliis affection i.s often very troul)lesomc in the tropics. It may sometimes
be avoided by attention to tlie clothing — wearing light linen or cotton
garments instead of flannel, which can be done when the temperature is
equable. The annoying heat and itcldng are relieved by the application of
carbolic solution to the skin (about a table-spoonful of carbolic acid to a
pint of water). A good saline purge should always be administered at
the beginning of an attack.
Ring-vorm.
This disease is infectioiis, as it is propagated by spores. These spores
cut into the hair close to the skin, so that it becomes brittle, and breaks
ofif near the surface. The hairs close to the affected spots should be
plucked out one by one, so as to isolate it, and the part should then be
frequently dressed with strong carbolic lotion, painted with liniment
of iodine, or strong solution of corrosive sublimate.
Sea- Sickness.
As is well known, some travellers are martyrs to this extremely
distressing affection. Others suffer a little at first, but the symjitoms
wear off when they have become accustomed to the motion of the vessel.
Some do not suffer at all. A great deal depends then on the nervous
constitution of the patient. As every traveller from the British Isles has
first to encounter the trials of the surrounding ocean, it is, of course,
very desirable that he should be prepared to meet this early difficulty. I
have usually found that the best preventive preparation of the system
consists in having a saline purge administered on the day before the
intended embarkation, and a comfortable meal immediately before going
on board. A cup of strong tea, or strong black coffee, taken after
starting, is a very efficacious preventive remedy in many cases. AVhen
symptoms threaten, the horizontal position should be assumed at once,
with the head as low as possible ; a hot jar to the feet, and a hot poultice, or
sinapism, to the pit of the stomach, will then check the progress in most
cases. On this account, persons who are specially prone to sea-sickness
should, on getting on board, retire at once to their respective berths. A
tight belt is sometimes t;seful.
MEDICAL AND SUEGICAL HINTS. 61
Sleeplessness.
This is often a distressing symptom, especially in the case of persons
already weakened by malarial and other affections, who are, indeed, the
most likely to suffer from it. It is also produced by excessive heat or
cold, the irritation of mosquito bites, the annoyances of other insects and
parasites, the abuse of tea and coffee, and, of course, indigestion. Cold-
ness of the feet is a potent cause. On this account it will often be found
that strong kneading of the feet and legs often acts as a powerful
sedative. The application of a hot-water bottle to the feet sometimes
acts like a charm in causing sleep. When there is troublesome indiges-
tion, the application of a hot poultice to the stomach has a similar
soothing effect. Oi^ium, bromides, chloral and sulphonal are useful.
Sunstrohe.
This deadly affection is by no means characteristic of sub-tropical
climates. The present writer has seen more cases by far in England than
in Africa, during nearly nine years' experience of the vicissitudes of the
" Dark Continent." It is said to be decidedly rare in the insular regions
of the trollies, as in Jamaica, Ceylon, etc., and the progress of the Emin
and Gordon Eelief Expeditious was singularly free from it. It must
always be looked out for when the surrounding temperature exceeds that
of the surface of the body, 98*4 E. It may be produced either by direct
cx]3osure to the sun's rays, or by the influence of a super-heated atmo-
sphere. Sometimes the patient falls down suddenly. In a larger pro-
portion of cases, premonitory symptoms are present: giddiness, sickness
of stomach, peculiar heat and dryness of the skin, blood-shot eyes, and
frequent micturition. In such cases, the attack can, probably in every
instance, be warded off by prompt treatment. The ijatient should at once
be drenched all over, especially on the head and along the spine, with cold
water, and this treatment should be kept up for a considerable time. A
large dose of calomel should also be placed at the back of the tongue, or
better, in very urgent cases, a turpentine enema should be given as
quickly as possible. The patient can then be made comfortable in bed,
with cold wet cloths wrapped around the head and adjusted along the
spine. They should be frequently changed and wetted, so as to prevent
them from getting warm, and this treatment should be persisted in till
the patient has been roused.
02 HINTS TO TRAVELLERS.
Parasites.
Worms arc nearly always introduced into the system through the
lucdia of unfiltcred water, or imperfectly-cooked food. The same may be
said of other internal parasites. There are exceptions, as we .shall see
later on.
Intestinal worms are divided into two great classes: the tape worm
and the round worm. Each of them gives rise to a series of intestinal
derangements, but the diagnosis of their existence can hardly ever be
made with certainty except when a part, or the whole, of a worm has
been passed with the evacuations from the bowels. Accordingly, the
great preventive treatment, obviously, is the careful adoption of proper
precautious with regard to food and drink. For curative treatment, the
liquid extract of male fern (thirty drops beaten up with yolk of egg), or
large doses of turpentine (one to two fluid ounces — two fluid ounces
b(>ing equal to a wineglassful), will be found effective. For the round
worm, a full dose of santonin (six grains for an adult), followed by a
purgative, is always eflficacious.
The guinea ivorm, which is a very common and very troublesome para-
site in the countries around the Eed Sea, is also introduced with food or
drink into the alimentary canal, but makes its way to the subcutaneous
connective tissue, which is the only place in which it develops. It gives
rise to very troublesome sores, and can be removed only by a careful pro-
cess of extraction, for which a skilled hand is always necessary.
Care of infants and children.
In the care of young children, the flrst thing to be thought of in
foreign climes, as at home, is the necessity for warm covering; the second
is the administration of proper food, and at regular intervals. The more
active tissue-changes accompanying the gi'owth of children is accom-
panied by the evolution of larger proportional quantities of heat than in
the adult. The greater proportion of surface to persons in early life
favours the dissipation of this heat by radiation. The heat-regulating
mechanism is not so well developed in very early life, and, accordingly,
a slight disturbance of the system causes a greater proportion of febrile
disturbance. The pulse is also disproportionately quickened in the
MEDICAL AND SURGICAL HINTS. 63
illnesses of childhood. Gastric disorders are also very easily induced at
this period of life, as the digestive organs are very delicate, and their
functions are easily deranged. On this account, the clothing, as well as
the diet, of young children should always be attended to with great care.
It is a terrible mistake to think, as many people seem to do, that rough
and ready treatment in very early life will help to make young people
more hardy afterwards. Excei^tionally robust constitutions may resist
the effects of these mistaken notions, but there is no doubt that the seeds
of chronic disease and of permanent delicacy of constitution are often
laid in this absurd management of childhood. Bare legs, bare necks,
and arms are too often displayed in childhood, and invite the future
development of rheumatic and tubercular affections. These parts should
always be protected— in the varying seasons, and in different climates,
according to temperature and surroundings — with thicker or thinner
clothing, as the requirements of the cases demand.
The abdominal organs are, as is well known, extremely susceptible to
the effects of extremes of temperature, and of local irritation, in child-
hood. On this account, a flannel binder should always be worn by
children in sub-tropical regions, where such influences are most likely
to be felt. The effects of chill are severely felt in childhood, but warm
drinks, rest, eqiiable temperature, gentle purgatives, and subsequent
careful feeding will nearly always suiflco to neutralise them.
The nervous system is also extremely susceptible in childhood. The
effects of reflex irritation due to some local cause, such as the cutting
of a tooth, or the presence of intestinal worms, are such as often to
give rise to most alarming symjitoms, such as convulsions, delirium, or
paralysis. The onset of fever in early childhood is also frequently
marked by a severe attack of convulsions. In estimating the severity
of febrile symptoms in childhood, too much attention should not be
attached to the rate of the pulse, which is very easily quickened to an
extreme degree at this early stage of life.
At the onset of any high fever in children, one of the best initial treat-
ments is the use of the hot pack. A blanket should be wrung out of
water as warm as can be borne without positive discomfort, and the child's
body may be wrapped in it, and the ends turned up and pinned, so that
no current of air can circulate between it and the skin.
When purgation is required, mild doses of castor oil, of fluid magnesia,
64 HINTS TO TRAVELLERS.
or of liriuorice powder, can always be used with advantage. Mercurials
are often abused in childhood, and should rarely be employed without
skilled advice. Opium is dangerous. A generous diet, with fresh air,
will prevent the development of rickets, wliich leaves such painful
deformity in the unhappy subjects who are affected by it. It is very
generally found in children who have been brought up on artificial foods
and milk. The milk of very delicate mothers will also predispose to its
development. Fresh air, with a well-selected and varied diet, including
the important factors of good cream and some cod liver oil, will be nearly
always found sufhcient to arrest the disease, if it has not already pro-
ceeded too far.
The distressing afiectiou known as spasmodic croup is specially common
among rickety children. It should be treated by a warm bath, tlie use
of a full emetic, inhalation of hot steam, application of hot sponges to the
throat, and, of course, rest in bed. Eepeated doses of chloral have a good
effect afterwards.
Convulsions are also treated by use of the warm bath, and sedatives,
such as a mixture containing chloral, with bromide of sodium or
ammonium. It must be remembered that disordered bowels, the presence
of intestinal worms, and the onset of fevers, are the commonest causes of
convulsions during childhood.
During teething, great care must be taken of delicate children. They
are frequently attacked by convulsions — sometimes by reflex paralysis.
These can, however, be nearly always checked by regular use of laxatives,
and of the warm bath. Lancing of the gums must be resorted to when
necessary.
Diarrlava is a common afiectiou of childhood, and usually requires a
treatment beginning with the use of a purgative, as it is very generally
dependent on the presence of some irritating substances in the bowels.
Thrush is nearly always due to some derangement of the stomach or
bowels. Attention to diet, following the administration of a castor oil
purgative, and the application of borax and honey to the interior of the
mouth, will be found effective treatment in almost every case.
Worms are often very troublesome, and especially in the tropics, where
intestinal parasites are oftener found than in temperate climates. They
give rise to intestinal derangements, disorders of appetite, flatulence,
griping pains, diarrhoea, restlessness, grinding of the teeth during sleep.
MEDICAL AND SURGICAL HINTS. 65
and other misleading symptoms which have been already referred to,
such as convulsions and paralysis. Two kinds of worms are compara-
tively frequent in children : the round worm, which is found high up in
the bowel, and the thread worm, which is always found near the lower
orifice. Santonin is an effective remedy for the former ; the latter is best
treated by an injection of some bitter fluid, such as infusion of quassia.
Wasting in children is generally associated with chronic diarrhoea;
and is, very usually, connected with an unhealthy condition of the in-
testinal glands. The limbs become extremely thin and worn, and the
abdomen tumid to an enormous degree. In such cases, great care must,
of course, be taken with the diet. Cow's milk is generally very badly
digested in such cases. Starchy foods, being fermentable, also disagree
very much. Condensed milk, diluted with thin, freshly-made barley-
water, is much easier of digestion. If cow's milk must be used, it should
always be diluted with water and given warm. The addition of lime-
water, about one-third the bulk, is often very useful for delicate children
— especially where a tendency to rickets is threatened,
B.— Surgical Diseases and Injuries.
Bleeding (Haemorrhage).
Serious bleeding is of two kinds: arterial and venous. Arteries are the
vessels which convey the blood from the heart away to the tissues. When
one of them is divided, the blood, which is bright red in colour, escapes
in jets, with considerable force and velocity ; so that, if the wounded
artery is a large one, there is great danger of immediate death. On the
other hand, when a vein is divided, dark-coloured blood flows out quietly
— it never spouts to a distance. The veins are the vessels which convey
the blood back to the heart from the tissues : they are connected with
the arteries by microscopic channels called capillaries. Bleeding from the
capillaries is very rarely at all dangerous.
When serious bleeding occurs, the patient should be at once placed
in the horizontal position, and pressure applied to the bleeding point.
When an artery is wounded, pressure should be applied to the bleeding
vessel on the side next the heart ; when a vein, it should be applied away
from the heart. The reason is obvious, if the direction of the blood
66 HINTS TO TRAVELLERS.
current is renieml)ered. If the bleeding be from a puncture or a small
incision, direct pressure with the finger, and subsequent application of
pads carefully bandaged in position, is the best that can be done, till the
arrival of skilled surgical aid. Before this can be procured, continuous
pressure maybe absolutely necessary : will inevitably be, indeed, except
some special apparatus is at hand. If there are several persons present
to assist, the pressure can be taken by each in turn, as the exertion of
keeping it up, although apparently slight, is well known by those who
have had to practise it to be extremely tiring. If no other means are
procurable, the application of a tight Ijandage (in case of wound of a
limb) above the seat of injury will be an effective check to profuse arterial
bleeding. A^cnous bleeding can nearly always be readily checked by local
pressure. If an elastic bandage be carefully applied it will arrest any
hasmorrhage from a wounded limb. If a piece of India rubber tubing
can be procured and tightly applied above the seat of injury, in case of
wound of a limb, it will be found an effective method of arresting the
bleeding. The oldest form of tourniquet consisted in tying a hand-
kerchief around a wounded limb — then inserting one end of a stick
between the handkerchief and the skin, and twisting forcibly. The
effect is obvious, and will certainly jirevent fatal hsemorrhage if done
in time. Arterial bleeding from the j^alm is very troiiblesome. It may
be treated — till skilled assistance can be procured — by bandaging the
fingers, placing a rounded pad in the palm, on which the fingers are
then closed ; the bandage is then carried up to the elbow, when the
joint is flexed and secured in that position by the bandage. The arm
should then be supported in a sling.
In the case of wounds high up in the arm, or in the arm-pit itself, the
subclavian artery must be controlled by pressure against the first rib.
This is applied from above the collar-bone. In the case of serious wounds
high up in the lower limb, the femoral artery can always be secured by
pressui-e in the middle of the fold of the groin. In the case of the leg
below the knee, the latter joint should be firmly bent, and the limb well
bandaged from below upwards. A pad should be placed on the bleeding
point, and the knee firmly secured in the flexed position by the bandage.
Stimulants should be avoided after ha3morrhage, as they increase the
activity of heart, and tend to renew the bleeding.
MEDICAL AND SURGICAL HINTS. 67
Blisters on the feet.
These are generally caused by creases iu the socks, or some roughness
on the inside of the boot, during a long walk ; accordingly, the pre-
vention is obvious and easy. Great care should be used in the selection
of boots and socks, as blisters are very painful and annoying. When
they have been formed, they should be pricked — to let out the fluid — and
good adliesive plaster apjilied, which will protect the raw surface
effectually. ^Yhen the feet are naturally tender, and jDrone to form
blisters on slight iDrovocation, soaking them for some time in tepid salt
and water, before jDutting on the socks in the morning, has a very good
effect. Eubbing the insides of the socks with soft soap is also a very good
preventive. Knitted socks are the best.
For tender feet, of course, very comfortably fitting boots should always
be carefiilly selected before travelling. Broad and low heels, and elevated
and broad toe-caps are desirable features. It should also be remembered
that it is a decided mistake to wear too large boots for long walks.
Boils and carhuncles.
These well-known affections differ in degree rather than in kind. The
carbuncle is an exaggerated boil; it tends to spread considerably in some
cases, and is indicative of a feebler state of the general system. On this
account, the use of generous diet and stimulants is indicated where a
carbmicle forms. Both require iDrotection and poulticing. When the
carbuncle is extremely tense and painful, a free incision along the length
of its greatest diameter, or the destruction of the skin over its central
part by means of caustic potash, will be found the most effective means
of relief.
For boils, poulticing, free purgation, and a light, well-chosen diet are
the only general remedies that need be employed, also a small incision
to evacuate pus if necessary.
Bruises.
A bruise, when recent, should be treated with a cold lotion, irrigation
with cold water, or application of wet cloths — very porous and often
changed — or a more carefully-prepared evaporating lotion.
F 2
68 HINTS TO TRAVELLERS.
Burns.
Where an extensive l)nrii or scald lias occurred, the clothing of the
affected jiart should be removed by cutting, so as to cause as little irri-
tation of the burnt surface as possible. Lint (or rags of some kind, if
lint cannot be procured) should he thoroughly moistened with a mixture
of equal parts of olive oil and lime-water, and applied to the injured
surface. If this dressing is not to be had, flour or powdered starch
should be dredged over the surface till completely covered, and then pro-
tected from being rubbed off.
Chilblains and frost-hifes.
Chilblains are usually found on the fingers or toes, after exposure to
severe cold, when tightly compressed — by the gloves or boots, as the case
may be. Some persons are specially liable ; and the best way to promote
their formation certainly is to toast the semi-frozen fingers or toes, at
a fire or stove, before the circulation has been re-established. Similar
conditions, more aggravated and prolonged, lead to the development of
frost-bife.
Chilblains are checked in the beginning by painting with tincture of
iodine or strong solution of nitrate of silver. AVhen threatened, the part
should be well rubbed with snow, or with camphorated spirit. Ulcerated
chilblains can be effectively treated vrith boracic ointment spread on lint.
Frost-bite shovild be treated in the beginning by very vigorous friction
with snow or pounded ice. The affected parts should be then well
wrapped with cloths wet with cold water. It is extremely dangerous to
bring the frozen part near a fire. Afterwards, the part should be wrapped
in cotton wool. If the case is a bad one, or injudiciously treated, gangrene
always follows; if this is extensive, amputation will be necessary.
Concussion of the brain.
This term is given to the condition accompanying the partial suspen-
sion of the functions of the brain produced by the severe shaking of its
substance by a fall or blow. The patient lies in a semi-imconscious con-
dition, with cold, clammy skin, and very feeble pulse and breathing. He
MEDICAL AND SUKGICAL HINTS. 69
can be somewhat roused by shouting into his ear, and cries out when
painful aijplications are made, but quickly relapses into insensibility. In
these cases, a large turpentine enema should be given at once, and a full
dose of calomel or croton oil (in a little mass of butter) placed on the
back of the tongue, when it will be swallowed by the reflex action of the
muscles. When reaction sets in, the head should be kept cold, with an
evaporating lotion or an ice bag, and the bowels still kej^t very free.
Stimiilants should be avoided in cases of concussion of the brain ; they
tend to cause too violent reaction, which would be followed by inflamma-
tion of the brain and its membranes.
Drowning.
It must be remembered that, in cases of submersion in water, the great
object is to restore the action of breathing. If the heart's action has not
completelj stopped, this can always be done by skilful treatment. In
order to succeed, it is absolutely necessary to quickly clear out the air
passages. For this purpose, it is well to place the patient in such a
position that the head is lower than the body, and the body itself on an
inclined i^lane, sloping downwards towards the head. In this position
the water will tend to drain from the air j^assages. The tongue should
instantly be drawn forward, and the mouth and nostrils cleared of froth
and mucus as completely as possible. The patient may be first placed on
his side, with the lower arm raised to the level of the face. The other
arm should then be firmly grasped between the elbow and shoulder, and
with it the patient should be drawn roiiud so as to lie on his back, the
arm being at the same time firmly drawn above the patient's head. He
should be then rolled round to his face, during which movement the arm
miast be brought down to the patient's side, and forcibly pressed against
it, while the patient is on his face. After some time, firm pressure should
be made by the knees against the back, between the shoulder-blades.
This series of movements should occupy a time of between three and four
seconds, and must be regularly repeated for about five minutes. At the
end of this time, a great part of the water will have drained away throughi
the mouth and nostrils. If breathing has not then been re-established,
the patient should be rolled on to his back, and the operator, standing
behind the head, should grasp the arms above the elbow, and raise them
70 HINTS TO TRAVFJJ,KRS.
slowly ahovo the head as far as they can he drawn, hold them there for a
.second or so, and slowly depress them to tlic sides. AVhcn in contact with
the sides, they should l)e pressed as firmly as possil)]e af^ainst the cliest.
The same series of movements should then be r(^])eated about tAvcnty
times per minute, as in the other case. This manipulation should he
continued for eve7i several Jionrs, so as to establish rcsi)iration if possible.
Fractures and dislocations.
The commonest of all fractures is that of the coJJar-hone. The bones
of tlie limbs, and the ribs, arc also frequently broken. The nature of the
injury is known by the mobility of the fragments, and the yrutiiKj (which
may be hothfelt and hvanl) when the fragments are moved against one
another. When a fracture occurs, the ])arts should be brought liack
to their natural position as soon as possible, and firmly retained in that
position by means of splints and bandages. In case of fractures of the
arm-bone, and of the thigh-bone, there is a great tendency to shortenirifi
of theh'mb by the contraction of the muscles around the broken l)one,
which, if not carefully counteracted, causes over-riding of the broken
extremities.
Splints can be extemiwrised by cutting pieces of board of moderate
thickness into appropriate lengths. If boards are not procurable, rods or
straight sticks can be cut into corresponding lengths, and secured
together with strings, as shown in the figure. In case of fracture of
the thigh-bone permanent extension must be kept up, otherwise the
limb will be shortened.
If no other supports for a broken limb are jirocuralile, considerable
protection will be afforded by filling stockings or shirt sleeves with sand
or earth, and placing them on either side as the patient is lying down.
Bundles of rushes, strong reeds, or iron wires tied together, arc also
sometimes emjiloyed.
Fracture of the collar-hone should be treated by placing a large
MEDICAL AND SURGICAL HINTS. 71
pyramidal pad, about six inches long by three in thickness at the upper
end, in the arm-pit, and securing it with tapes tied over tlie opposite
shoulder. The elbow should then be brought forwards, and raised and
well supijorted by a broad triangular bandage, or handkerchief, used as a
sling, and with the ends tied over the opposite shoulder, at the root of the
neck. A flannel roller can then be passed loosely round the chest several
times, so as to secure the arm ft'om accidental movements.
Fracture of the ribs should be treated by wrapping a flannel roller
around the chest pretty tightly, so as to limit the movements of
respiration, which arc very painful. It should be secured by stitching,
and the upper turns should be fixed by broad tapes passed over the
shoulders and firmly stitched. Firm strapping of the side with adhesive
plaster is still better, and should be used if possible.
Fractures of the upjper arm may be treated by the application of several
narrow splints, well padded, and supported in position by a bandage
carried from the fingers to the arm-pit. Care must be taken that the
splints on the inner side do not chafe the folds of the axilla. The hand
and wrist should then be supported in a sling, but the elbow must be
allowed to hang free.
Fractures hetiveen the lurist and elbow must be treated by two splints, each
wider than the limb. One is placed behind; the other iu front. The
former reaches down to the finger-tips, the other not beyond the palm.
In seciTring them in position the thumb must be placed upwards, and the
whole limb, from elbow to wrist, supported in a sling, with the hand a
little above the level of the elbow. Too much pressure must never
be used in adjusting the bandages, and these should always include the
fingers.
Fractures of the loiver Jimb are much more serious; they require the
patient to keej) lying down till union has been effected, and they are
more likely to lead to permanent deformity if not very carefully treated.
Those of the thigh invariably produce shortening and permanent lame-
ness, if not treated by a skilled surgeon.
Fractures of the leg can usually be fairly well adjusted by extending the
limb so as to remove the deformity, applying a splint on each side, long
enough to reach from the knee to a little below the sole of the foot, and
bandaging them in such a ]iosition as to liave the great too in a line with
the inner border of the knee-cap. It is not, comparatively speaking, so
72 HINTS TO TRAVELT.ERS.
hard to keep the limb in position, as in otlicr fractures; and, accordingly,
very crude apparatus, e.<j. an umbrella on each side, will often be found
fairly serviceable in tlic absence of properly-prepared splints. They may
also be tolerably well supported by thick pads on each side formed of a
great -number of layers of cloth of some kind (calico, etc.) and tied in
that position. When the accident occurs in the open air, the injured
limb should be tied to the sound one, till the patient is brought to a place
of security.
Compound fractures, i.e. fractures in which the broken ends are exposed
by a wouiid, or actually protruding through the skin, are very serious
injuries uiien occurring beyond the reach of skilled assistance. In such
cases, all dirt should be removed from the wound by syringing with tepid
water, to which a little weak carbolic solution should afterwards be
added, if procurable. The parts must then be adjusted by very careful
extension, and pressure, if the fragments protrude. Splints are then
applied as in other cases, but the bandage must not be carried over the
opening in the skin. This should be covered by a carbolized pad, and
kept loosely in place by a piece of flannel roller, so that there shall be
no obstacle to the escape of discharges.
Dislocations can hardly be discussed here with much advantage, as they
nearly always require skilled aid. The most frequent is that of the
shoulder, which is generally easy to diagnose. The patient cannot raise
his hand to his head, and the joint is rigid when anybody attemiits to
move it for him. This dibtinguishes the injury from a fracture. The
shoulder is flattened, and the elbow sticks out from the side ; while the
length of the limb is usually somewhat increased. The reduction can
generally be effected by placing the patient lying down, inserting the
unbooted heel of the foot of the same side in the arm-pit^ and drawing
the arm firmly and steadily downwards, while the heel is made to press
against tlie head of the bono in the outward direction. Dislocation of the
bones of the fore-arm backwards at the elbow joint is pretty common,
and can usually be redixced by placing the knee in front of the patient's
elbow, and making firm traction on the forearm — which is at the same
time flexed a little around the ojDerator's knee. The i^atient can be kept
sitting in a chair while this is done, and the operator can get his knee
into the required position by placing his foot on the side of the chair.
MEDICAL AND SURGICAL HINTS. 73
Parasites.
The jigger (Pulex penetrans) is one of the parasitic pests of tropical
climates, and often gives a great deal of annoyance. It lodges in the
skin, in whicli it burrows, and establishes so firm a hold that it must be
j-iicked out with a pointed instrument. After it has been dislodged, the
part should be well smeared with carbolic oil.
Ticks also give rise to a great deal of trouble by burrowing in the skin,
where they i^roduce intense itching and irritation. They are sometimes
found in the nostrils. They should be similarly treated.
Leeches abound in the long glass of certain tropical districts — notably
of India and Ceylon. They attach themselves to the skin, and have often
been known even to cveep into the nostrils, where their bites cause
considerable loss of blood. They are best removed by salt and water —
applied to the surface, or injected into the nostrils, as the case may be.
Fleas and hugs may be kept at a respectful distance by the use of
" Keating's Insect Powder."
Mosquitos are very abundant in many sub-tropical countries. They
must be warded off by the use of netting, as already described.
Midges can be dispersed by smoke.
Rupture.
A rupture is a protrusion of a portion of the intestine under the skin,
and is usually found in the groin. It is generally reducible, i.e. it can be
pushed back into the abdomen. It reappears when the pressure is re-
moved, especially if the patient is asked to cough. When reduced, a
properly fitting truss should be applied, and always worn during the day.
It can be taken off at night, after lying down; it should be again adjusted
in the morning, while the patient is still lying.
The great danger of rupture is that it may become strangulated. This
occurs when the bowels are neglected, or when a large portion of the
intestine is suddenly forced out by some severe exertion. If unrelieved,
this complication is always fatal. The existence of strangulation is known
by local pain and tenderness, development of severe colicky pains in the
abdomen (especially about the navel), vomiting, hiccough, and symptoms
of collapse. When this condition is observed, the jjatient's hips should
74 HINTS TO TRAVETJ.ERS.
lie raised, hy supporting them with pillows till higher than the head, and
the tninoiir should Ije gently kneaded and pressed with the view of
getting back the protruded intestine. The treatment is considerably
aided by immersing the patient in a warm bath, and giving a full dose of
opium^-abont thirty or forty drops of the tincture, or in tabloid form.
Placing ice around the tumour for half an hour or so is often very
effective. If these means fail, surgical aid is absolutely necessary.
Snake-bite.
Provision should be made against snake-bites by wearing stout gaiters.
Bites of poisonous snakes are generally recognisable by the fact that the
fangs make well-defined circular punctures, while the other teeth make
only minute scratches. In the case of sea-snakes, which are generally
very vcuemous, the fangs are very small, so that this distinction is not
always available.
Sir Joseph Fayrer recommends the following treatment for snake-
bites : " Apply at once a ligature or ligatures, at intervals of a few inches,
as tight as you can i^ossibly tie them, and tighten the one nearest to the
wound by twisting it with a stick or other such agent. Scarify the wound,
and let it bleed freely. Apply either a hot iron or a live coal, or explode
some gunpowder on the spot, or apply either carbolic acid or some mineral
acid or caustic. Let the patient suck the wound whilst you are getting
the caustic ready, or if anyone else will run the risk, let him do it.
" If the bite be on a toe or finger, especially if the snake has been
recognised as a deadly one, either completely excise, or immediately
amputate at the next joint. If the bite be on another part, where a liga-
ture cannot be applied, or indeed if it be on the limbs above the toes or
fingers, cut the part out at once completely.
"Let the patient be quiet. Do not fatigue him by exertion. Give
eau-de-luce or sal-volatile, or carbonate of ammonia, or, even better than
these, hot spirits and water. There is no occasion to intoxicate the
person, but give it freely, and at frequent intervals."
Bites from jackals should be treated on the same principles as those
above recommended for snake-bite, as they are sometimes followed by
hydroi^hobia.
MEDICAL AND SURGICAL HINTS. 75
S2yrains.
These usually occur at the ankle joint. The affected joint should
always be raised on pillows, and treated with cold evaporating lotions
— thin cloths moistened with cold water and frequently changed, if
there are no other remedies at hand. If inflammation be developed,
warm fomentations will be foimd more soothing. Leeching may also
be necessary, and free purgation has always a good effect. The trouble-
some stiffness which often remains is best treated by friction and
kneading with the hand. This hand- friction will be found very bene-
ficial, if well applied at the moment of the occurrence of the injury ;
but, if inflammation has had time to develop, it should not be attempted
till this has subsided.
Ulcers.
Ulcers are often very troublesome in tropical climates. They occur
usually on the limbs, and especially on the lower limbs, where they
often spread from the most trifling abrasion of the skin, caused by a
puncture or a scratch, or by the bite of some i^arasitic insect. Their
spreading is, of course, greatly promoted by exposure to the sun "s heat,
the rubbing of the clothes — or of foreign bodies with which they may
come into contact. Want of sufficient nitrogenous food is also a potent
factor in the rapid development of large ulcers.
When the ulcer can be i3rotected, and rest can be given to the affected
part, a simple dressing of zinc ointn,ent, ointment of boracic acid, or
iodoform is usually effective. When the ulcer is deep and large, it may
be stimulated to healing by the application of lint or cotton-wool,
moistened with carbolic acid (one part of carbolic acid to twenty parts
of oil). In the huge gangrenous ulcers of which I have had to treat
an enormous number in Equatorial Africa, I have found nothing so
effective in checking their i:)rogress as the application of pure carbolic
acid to the edges and base. If very large, the whole surface should not
be so treated at once. Afterwards, the dressings above mentioned will
suffice, if rest and generous diet can be procured.
76 HINTS TO TT^AYEIJ.KTIS.
Womids.
Slight, clean-cut wounds are best treated by bringing the edges
together, and securing them in contact by means of strips of adhesive
plaster carefully ajiplied, and then brushed with flexible collodion. If
there happen to be any dirt, or particles of any kind, engaged in the
wound, they should always be removed previously by very careful
washing. A weak carbolic solution should then be applied before the
parts are secured in position. If there be much bleeding, it must always
be checked before the wound is closed. The means for doing this have
been described under the head of " Bleeding." In cases of lacerated
wounds produced by the bites or gorings of wild animals, and in cases
of gun-shot wounds, great pains should always be taken in washing the
parts out thoroughly with carbolized water before bringing the edges
together. In such cases, stitches will be required to keep them in position.
Every shred of skin should be preserved with the greatest care.
In cases where there is much bruising, a good deal of inflammation is
likely to follow; and it is always useful, if the patient has not been
weakened by loss of blood, to administer a full saline purge. Bruises
without much breach of surface should be treated at first with cold
lotions ; when inflammation sets in, poultices will be required.
In all cases of deep wounds, it is well to have all instruments, the
operator's and attendants' hands, and all dressings applied, well soaked
in carbolic solution, about one of carbolic acid to twenty of water or oil ;
or in a solution of perchloride of merciiry, 1 in 2000 strength.
Rules for the Preservation of Health ix the Tropics.
(^From ' Experiences in Equatorial Africa,^ by T. H. Parke.)
Water. — All drinking-water, no matter how sparkling and pure, should
be invariably boiled to insure its freedom from dangerous constituents.
Cold weak tea, without sugar or milk, is best for the march. Water
should always be drawn from up stream, and from the centre if jDossible.
Two grains of permanganate of potash to the quart purifies water. If
muddy, use alum.
Sun. — No precautions can be too great for protecting the head from
MEDICAL AND SURGICAL HINTS. 77
the direct rays of the stin. The use of a proper head-dress and umbrella,
also a spinal pad for morning and evening sun, is judicious.
Chills, draughts, sitting in damp clothes, especially when heated after
violent exercise and coiDious perspiration, also cooling of the body
suddenly in any way, are certain to be followed by fever.
Clothing. — The bodily temperature should be kept as equable as
possible. Loosely-fitting woollen clothes are preferable. Light kamdr.-
band should be worn day and night. On halting after a march put on a
wrapper so as to cool gradually. Get under cover and change, if
jjossible.
Sleep as far as possible off the ground, and always under mosquito
curtains at night.
Diet should be plain: meat, fish, vegetables, well-boiled, fruit, rice,
and cereals.
Alcohol habitually, especially during the day, is most dangerous;
medicinally, on occasions, it is useful.
Tub in the early morning, or at the end of a march, before cooling,
never while digestion is going on, and always tepid if possible.
Camp. — Select highland plateau near water supply. Don't disturb
the soil. Avoid ravines. Never to leeward of a swamp, unless separated
by a belt of trees or a river. Site of latrine should be selected im-
mediately on halting, and covered with a hurdle and sods so as to exclude
flies, as they convey blood poison — leaving only a few openings, each
about one foot square. Directly tent is pitched hoe a gutter close to
the walls in case of rain.
Cleanliness. — Hair should be cut short.
List of Useful Articles.
(From ' Guide to Secdth in Africa,' by T. H. Parke.)
For One Person to take on an Expedition, calculated to last Two Years, and
making Four Men^s Loads not exceeding Sixty Pounds each.
Tent, measuring seven feet every way, two and a half feet walls, with
poles, and fly made from "green rot-proof" canvas; pole-strap, mallet,
twelve long galvanised pegs; not to exceed 60 lbs. in weight. The
78 HINTS ro TRAVELLERS.
" Tortoise " is the best design for a large party. (Benjamin Edgington,
London.)
Valise, made from strong waterproof canvas, to hold "Parke Africa
bedstead," folding armchair (brass fittings), hair mattress, bell-shape
mosqiiito curtain, with the apex suspended from a hook, fine gauze to
make a few cylindrical veils for keeping off flies, etc. ; two long blankets;
waterproof ground sheet, about six feet by five feet, so as to improvise a
Tente D^Ahri if required; portable india-rubber bath, and basin; small
down pillow, with six washing covers, also clothes packed into valise
pillow. Not to exceed 60 lbs. in weight. (Eoss & Co., EUiss Quay,
Dublin.)
Canteev, containing three circiilar steel cooking-pots, nested, having
moveable handles; one coffee-grinder, one mincer, one gridiron, and one
ladle, with moveable handles ; three enamelled plates, shaped like saucers,
to fit one within the other ; one hot water plate ; knife, fork, and spoons
(tea, salt, and soup) ; three pudding-tins, nested ; enamelled teapot, and
kettle, one wicker-covered delf teapot, and cup and saucer; three
enamelled goblets, containing about a pint each, nested ; tins lined with
glass for salt, pepper, mustard, tea, coffee. Saccharine tabloids, grs. |,
most excellent substitute for sugar. The whole contained in galvani.sed
bucket, useful for drawing water, and covered by a lid which can be
utilised as a frying-pan. (Silver & Co., London.)
Box, portmanteau, or trunh, tin Japanned, air-tight, oblong in shape, or
solid leather, or basket-work covered with pig-skin, and lined with zinc, to
contain books {ejj. 'Qihle, Hints, large ' Whitaker,' &c.), i^apers, waterproof
envelopes, " toilet paper," ink in pellets, pencils, maps, ink-eraser, stylo
pen, gold nibs, sketching materials, matches in luminous boxes, clothes,
camphor blocks to keep away insects, etc. A waterproof canvas kit-bag
is most useful for clothes only. When packed not to exceed 60 lbs. in
weight.
Head-dress, Helmet, army regulation, with puggaree and curtain; night-
cap, and soft cap (deerstalker). (Hawkes, Loudon.)
Wuter-hotth, ebonite, covered with felt, to hold one quart.
Lantern, "Bercsford" folding, for oil or caudles. (Silver & Co.,
Loudon.)
Belt, " Colonial " leather waist, with strap over right shoulder, sheath
for unclasped knife, holster for light revolver, and small pouch, con-
MEDICAL AND SURGICAL HINTS. 79
taining ammunition, a flint and steel, bi-convex burning glass, and alarm
whistle on swivels.
Hammock, portable field, and, made of cord, useful to sleep in or for
transport.
Filter, pocket asbestos or charcoal.
Umbrella, with three spare covers (green).
Knife, pochet, skeleton, containing one blade, corkscrew, tin-oi:)ener,
champagne opener (useful to open boxes, etc.), screw-driver, gimlet,
tweezers, brad-awl.
Boots : brown shooting, four pairs ; three jDairs of Veldtschoons : the
former to be smeared with dubbing. Spare laces and a pair of boot-
trees.
Leggings, leather, one paii- reaching to the knee, and one short pair
merely to cover the top of the boot.
Pyjamas, silk and wool, with feet to keep out insects, six suits.
Waterproof coat, warm overcoat and one knitted jersey.
KnickerhocJcers, woollen material three pairs, to be loose, and securely
fastened by buckle and strap beneath the knee to prevent insects getting
up ; one pair of moleskin knickerbocker-breeches for riding.
Drawers, calico, short and loose, half-dozen.
Stockings : knitted, shooting, six pairs ; socks, six pairs.
Waistcoat, chamois leather, buttoning to the throat.
Tennis suits, flannel, for lounging in camp, two.
Putties, light woollen material, in fancy colours, two pairs.
Shirts, silk and wool, well shrunken, and loose about the neck, one
dozen.
Vests, light silk, six.
Gloves, leather gauntlet, three pairs.
Kdmdrhcind, silk, two.
Handkerchiefs, red silk, two dozen.
Towels, two bath and six small.
Holdall, containing hair, shaving, and tooth brushes, scissors, razors
(two) with strop, comb, soap, sponge, and looking-glass.
Housewife, for needles of various sizes, bodkins, thread, buttons, jDalm
and sail needles, tape.
Napkins, table, one dozen.
Compass, pocket magnetic.
80 HINTS TO TRAVELLERS.
Field-glasses, one pair.
Fish-hooks of various sizes, with line and baits.
Flea-powder, two tins.
Baking-powder, to make bread rise.
Medicines, small pocket-case, in tabloid form. (Burroughs, Wellcome
& Co., London.)
Goggles, green colour, two jiairs.
Trap, American wire, for catching birds, rats, etc.
Circular spring, for weighing.
Tape measure.
Haversack, for carrying luncheon, etc.
Tools, and spare screws fitted in small leather hand-case.
Extras : Arrowroot, sago, beef tea, " Liebig," three tins of each ;
brandy, two bottles ; curry-powder, anchovy paste, Erbswurst, custard-
powder, " composition " foods, celery salt, etc.
Transport.
The prospective traveller should give attention to the ways and means
by which those debilitated by sickness, or rendered helpless by wounds or
other injuries, may be conveyed when movement is necessary. The mode
of transport should be regulated in such a way as to prevent, as far as
possible, any aggravation of the existing weakness or pain. The recum-
bent position is, of course, by far the best — the easiest and safest — for
almost all cases. It is only for wounds and other injuries of the upper
part of the body that the sitting posture can sometimes be preferred.
In such cases, the " four-hand seat " (or " sedan chair " of school-boys),
forms a comfortable conveyance. Two assistants are required; each
grasps his own left forearm just below the elbow, and with the disengaged
left hand grasps the right forearm of the other also below the elbow-
The patient is then raised into the seat so formed and supports himself
by placing his arms around the necks of the bearers. Two bearers can
also, of course, carry a patient who is prostrated by loss of blood or other
weakness, in the horizontal position for a short distance, by standing
side to side, and holding the forearms in a horizontal position, while the
patient himself partially supports himself by grasping the shotdders of
tlie bearer who is next his head.
MEDICAL AXD SURGTCAL HINTS. 81
Of the modes of conveyance which are prepared for the transport of the
sick and wounded, the stretcher and hammock are the simplest. The
former, with the addition of a pole on each side, forms a very simple and
very efficacious means of transport for moderate distances. Two bearers
may be employed; four, if the services of so many are available. A
hammock, made from either cord or canvas suspended from a single pole,
is often employed, the ends supported on the shoulders of two bearers.
When nothing else can be procured, a great-coat, with the sleeves turned
inside out, and through which two rifles, poles or pikes are passed, will
be found to answer the purposes of an improvised stretcher fairly well.
In the use of all such modes of conveyance it is very desirable that the
movements of the bearers should be as gentle as possible. The steps
should always be short, and the front and rear bearers should always
break the step, by starting with opposite feet. This prevents dipping
from side to side, which would be, of course, very distressing to the
patient.
Animals can, of course, be employed as modes of convejance for the
sick and wounded. Whenever they are so utilised, the preference should
be given to the smaller ones — such as mules, ponies, and donkeys. The
invalid is then more readily raised into position, and more readily taken
down. It is hardly necessary to say that a steady, even gait, combined
with a fair amount of strength and power of endurance are to be looked
for ; and not at all such qiialities as high mettle, showy action, or speed.
A litter can be easily improvised, when the animal has been chosen.
The rai^idity and elficiency of the Arab method of conveying their
wounded from the field of battle has often been commented on, and is
well worth mentioning here. Mules are used for the purpose, and are
kept ready saddled. Two large sacks, stuffed with straw, grass, etc.,
are firmly corded— one on either side of the pack-saddle, and the grooves
between these and the saddle are filled by stuffing of similar material.
On the litter so formed, a cloak is thrown, and the helpless invalid is then
placed across the animal, lying in the recumbent position on the bed so
prepared. This arrangement reduces the jolting of the patient to a
minimum. If the emergency is very great, the person so placed can be
secured by tying, and can then be conveyed at a gallop, otit of the reach
of shot, etc. When there is a large party of travellers, supplied with all
the luxuries of transport, there are usually no such difficulties met with
o
82 HINTS TO TRAVELLERS.
as those I have implied. The presence of a sufficient number of
attenrlants, with animal transport, and properly-prepared litters and
cacolets, will obviate the necessity for the consideration already given.
"Wheeled conveyances may, of course, be utilised when there are roads.
Some other modes of conveyance may be mentioned, which have been
from time to time employed instead of the more primitive stretcher or
hammofk, viz. the Himalayan dandy, the trag-sitze of the Germans, the
New Zealand amoo, the Indian dooJey, the Chinese palanguin, etc., etc.
Any of these may be employed when at hand in the conveyance of the
sick and wounded. Ox hide and bamboo are nearly always at hand in
Africa, and are useful for making imj^rovised stretchers at the shortest
notice.
( 83 )
IV.
SURVEYING AND ASTRONOMICAL OBSERVATIONS.
By John Coles, f.r.a.s., Instructor in Surveying/ and Practical Astronomy
to the Royal Geographical Society.
Part 1.
INSTEUMENTS USED IN SUKVEYING.
Preliminary Remarks. — The intending traveller who proiDoses to under-
take the survey of an unexplored country, should make himself acquainted
with the use and adjustments of every instrument he purposes to employ ;
he should have a knowledge of plane trigonometry, and those computa-
tions of practical astronomy which are necessary to enable him to fix his
position in latitude and longitude ; and although from his note- book he
may furnish cartographers with valuable material, yet, without such
previous training, it is scarcely possible for him to map the country
through which he travels, nor will he be able to take full advantage of these
' Hints,' as the greater part of the matters dealt with will be beyond his
comprehension. The attainment of this necessary amount of knowledge
is by no means dilficult, and a few weeks of study, under proper instruc-
tion, ought, in most cases, to enable him, by the aid of the following
pages, to do useful geographical work. It is with this end in view that
this section of ' Hints to Travellers ' has been written in the simplest
form, in the hope that it may serve as an introduction to, without
at all superseding, the necessary text-books on practical astronomy.
84 HINTS TO TRAVELLERS.
1. Scientific Outfit.*
Sextant for regular work —
A sextant of 6-inch radius, light in weight, by a first-rate maker,
divided on platinum, to ten minutes, to read with vernier to ten
seconds. It sliould have a moveable ground-glass screen in front
of the reading-off lens, to tone down a glaring light. The handle
must be large and convenient ; the box capacious enough to hold
the instrument with its index clamped to any part of the arc, and
the receptacle for the inverting telescope long enough to allow of
it being put into the box when set at focus.
Sextant for detached expeditions, and for taking altitudes when the other
sextant is in tise for lunars —
A sextant of 3-inch radius, graduated to 20' to read witli vernier to
20", in a leather case, fitted to slip on to a leather belt, to be worn
round the waist, when required.
Mercurial Horizon —
One of the common form with folding roof by a good maker, or the
form devised by Captain George, k.n., may be preferred. {See
p. 107.) Reserve : an iron bottle of pure mercury.
Watches —
A keyless silver half-chronometer watch, not too heavy, with an open
face and a second hand. The hands should be of black steel, long
enough to cover the divisions. The divisions should be very clear
and distinct. See that the second hand falls everywhere truly upon
the divisions. Heserve : at least two more good watches ; these
should be rolled tip separately, each in a loosely-wrapped parcel of
dry clothes, and they will never come to harm ; they should be
labelled, and rarely opened. The immediate envelope should be
• It will be inideistood that the necessity for taking all the articles herein
enumerated will depend ujion the nature of the journey.
SCIENTIFIC OUTFIT. 85
free from fluff or dirt. Covers of chamois leather should be washed
before use. Three spare watch-keys; one might be tied to the
sextant-case, one wrapped up with each watch. {See p. 130 for
further particulars.)
ifew. .•—Chronometers are designedly omitted from this list, on
account of the proved difliculty of transporting them without
injury, and the frequent disappointments they have caused, even
to very careful travellers.
Compasses —
A prismatic compass, graduated on silver or aluminium, from 0^ to
360°.
Two pocket compasses, from I3 to 2 inches in diameter. The gradua-
tions on their cards should run from 0° to 360^, and not twice over
from 0° to 180°. A line for True North, temporarily marked on
the cards, in the position most appropriate to the magnetic varia-
tion in the country about to be visited, may be found convenient.
These compasses should be light in weight, have plenty of depth,
and be furnished with catches, to relieve the needle from its pivot
when not used. The needles should work smoothly and quickly :
such as make long, slow oscillations are to be avoided. Cards,
half black and half white, are recommended. (*S(e p. 93 for further
particulars.)
Steel Tape —
A 100-foot steel tape will be found very useful in measuring a
base, or when making plans. A fishing-line on reel for roughly
measuring a base, with knots at convenient intervals, will, under
certain circumstances, be useful.
Lantern —
All lanterns should be made of copper or brass, as they will
otherwise affect the compass reading when taking the hearing of
a heavenly body at night, and should be constructed for long
journeys and hot climates, to be used with oil, and furnished
with a large wick. A candle lantern is more convenient where
86 HINTS TO TRAVELLERS.
candles can be carried. See that tliere is abundant supply of
air-holes in the sides ; these are essential when the lantern is set
upon the ground. Also that all the internal fittings can be
removed and cleaned, and that they are solidly made, not merely
soldered. It should be furnished with a reflector, to throw a clear
light forwards and downwards. A moveable shade of light green
glass will be found to be a great improvement, as it prevents the
light from dazzling the eyes, and enables the observer to take the
reading on the sextant with greater ease. A good lantern is most
iiiiiwrtant. For general purposes, the Italian Alpine Club lantern
is one of the best forms. A small ball of sj^are wick, oil of the best
quality obtainable, and wax tapers, for use on detached expeditions,
should also be taken.
Thermometers —
Several sling thermometers.
A pair of maximum and minimum thermometers, fitted in one
case.
Three short and stout boiliug-jjoint tlicrmometers, with apparatus
for boiling them. {See p. 95 for fiirther particulars.)
Two ordinary thermometers, which should be graduated from 10^
or more below the freezing- to above the boiling-point.
Standard thermometers, at a charge of 17. each, graduated at the
Kew Observatory, may be obtained thence, on the application
of any Fellow of the Eoyal Society, or Member of the British
Association.
Aneroids —
Aneroids of ordinary construction should be of large pocket size
(2i inches across), capable of working without fracture over the
highest mountain pass that is expected. They can be obtained
graduated up to 20,000 feet at most instrument makers. At any
such height, however, their records are not to be depended on.
Aneroids are excellent for most differential observations, but
unreliable for ahsohde ones; they should be observed, as much as
possible, in conjunction with the boiling-point thermometers. Two
SCIENTIFIC OUTFIT. 87
are required, because simultaneous observations are important.
Eecollect that such observations, taken even at distances of two
or three hundred miles apart, are of value, as the areas are
usually very large over which the barometer has nearly the same
height at the same moment of time Watkin's patent Aneroid
differs from the Aneroid of ordinary construction by having its
scale drawn on three concentric circles, instead of the usual
single circle. This arrangement admits an increased scale of
graduation, and consequently of closer and more accurate reading.
It is manufactured by J. J. Hicks, 8, Hatton Garden. For Baro-
meters, see " Additional Instruments " (p. 89).
Mapping Instruments —
A small case of drawing instruments, containing, among other
things, hair-compasses, drawing-pen, and a rectangular protractor,
with scales of chords, sines, tangents, &c., engraved on it.
Marquois's scales, for ruling parallel lines at definite intervals.
Protractors : one circular, of metal, and one of celluloid, of 5 or 6
inches in diameter; one of vulcanite, 5 inches, all graduated, like
your prismatic compass, from 0^ to 360°.
A graduated ruler of 1 foot or more, in metal : 2 dozen artist's pins.
Medium size measuring tape, say 12 yards ; pocket ditto, 2 yards.
Stationery, &c. —
An artist's board, not less than 8 inches by 13, made of light, well-
seasoned mahogany, and what cabinet-makers call "framed," to
rule and draw upon.
Plenty of good ordinary paper. Rexiorters' note-books ruled (not
" metallic," for prepared paper wants strength, and the leaves of
such books are very liable to become torn out and lost ; they are
also damaged by wet). They should be all of one size, say
7 inches by 4i, or larger, and numbered. A leather pouch, secured
to the waist-belt, having a flap buttoning easily over, to hold the
note-book in use.
Two (or more) MS. books of strong ruled paper, foolscap size, each
88 HINTS TO TRAVELLERS.
with a leather binding; the pages should be numbered, and
journal observations, agreements, and everything else of value,
written in them.
Some sheets of blotting-paper cut up and put here and there in the
books.
Transparent cloth for tracing.
Plenty of brass pens and holders ; also fine drawing-pens (steel
crow-quills — Brandauer's Oriental pens are very good) and holder.
FH pencils; HB ditto.
Penknives. India-rubber cut up in bits.
Ink-powders of a kind that do not require vinegar. Eed ink.
Paints for maps, viz., Indian ink, sepia, lake, cobalt, gamboge,
oxgall, in a small tin case.
A dozen sable paint-brushes.
Materials for " squeezes," if travelling where inscriiDtions may have
to be copied (see page 455).
Paint and brush for marking on trees or rocks record of positions.
f}ooks, Maps, &c. —
Paper's Practice of Navigation ; or, in default of this, either Inman's
Navigation and Tables (bound together), or Norie's Navigation.
Chambers' Mathematical Tables are very comprehensive and useful.
Sliadwell'.s Cards of Formulae (Potter, 31, Poultry, Loudon) ;
Bethune's Tables for Tiavellers (Blackwood and Sons).
With the help of either of these two latter publications, the traveller,
who has a fair knowledge of mathematics, will thoroughly under-
stand what he is about, and may, on emergency, disi^ense with some
of the usual cumbrous tables, confining himself to ordinary
tables of logarithms. But we have recommended that all travellers
should be furnished with a complete set of tables, because they
afford at a single reference, what otherwise requires additional
trouble to obtain.
' Nautical Almanac ' for current and future years, strongly stitched
in cloth.
Some small Almanacs, such as ' Whitaker's,' contain tables of the
position of sun and planets, and of stars to be occulted. One of
SCIENTIFIC OUTFIT. 89
these is useful to aflfbrcl what is necessary to take on a detached
expedition, the required jmges being cut out of it.
More extended barometric tables than are given in this volume may
be procured at the instrument maker's, or cut out from Guyot's
elaborate Meteorological tables, published by the Smithsonian
Institution, New York.
Blank maps, ruled for the latitudes and longitudes of the proposed
route.
The best maps obtainable of the country you propose to visit.
Admiralty Manual of Scientific Enquiry.
Mem. : — Chauvenet's Astronomy (New York, 2 vols.) is one of the
most complete and thorough of the mathematical works on astro-
nomical observations; it is, however, a book for previous study,
rather than for reference in the field.
Additional Ijistriimetits, not necessary, hut convenient.
Theodolites— {See p. 108.)
Barometer — {See p. 97.)
Barometers of Fortin's jDattern were successfully carried to great
heights by Mr. Whymper, in South America; but the risk of
breakage, at all times very great, is proportionally greater on
longer journeys. The Boyleau-Mariotti barometer is an extremely
portable instrument, and is well calculated for use at great eleva-
tions (see p. 97). Captain George's barometers, which are carried
with empty tubes and filled when required, are much more
portable than the ordinary form of mercurial barometers; but the
filling them is a work of time and delicacy, which may be diflicult,
or even impossible, on a mountain top with an icy wind blowing.
Care should be taken to see that all barometers read low enough to
be used at great elevations.
Telescope for observation of eclipses of Jupiter's satellites, &c. {see pp. 214
and 235). One with a two-inch object glass, clear aperture, by a
good maker. It should be mounted on a split tripod, and furnished
90 HINTS TO TRAVELLERS.
with a Kelner eye-piece, of not less magnifying-power than 40,
and should be fitted with an arrangement by which it can, when
removed from the stand, be screwed finnly to a tree or other
support. The telescope should be tried on Jupiter, and found
•to give a satisfactory view of the satellites, before it is taken.
Plane tahJe.— Tv^o plane tables, and spare horse-hair for sight vanes.
They should be in strong canvas bags with leather-covered
corners, and furnished with straps, so that they can be carried
like a knapsack. For information as to use and the best form of
construction, see pp. 124-173.
Pedometer. — Apt to get out of order. If employed, at least three persons
should each carry one.
Clinometer.
Pocket level (Abney's), with a mirror to show where the bubble is, when
it is held to the eye. It also serves as a clinometer for the
measurement of slopes.
Jlain (jauge.
Examination of Instrumenti^.
Let every instrument be tested, and its errors determined and tabulated
at the Kew Observatory.* This is done for moderate fees. The following
are some of the present charges: — Watches, A class, £1 Is., B class, lOs. 6cZ. ;
ordinary thermometers. Is. ; boiling-point thermometers, 2s. M. ; marine
and portable barometers, 10s. &d. ; prismatic compasses, 2s. 6c?. ; theo-
dolites, 5s. ; superior sextants, 5s. Unifilars, dip circles, and other
magnetic instruments are also verified. The carriage of the instruments
to and from the Observatory must be paid. Address — " Superintendent
* This should be attended to by the traveller, especially in the case of ther-
mometers which have been previously examined at Kew Observatory, as it has
been found that their errors change considerably ; for instance, a boiling-point
thermometer which was tested in 1884 was found, in five years, to have increased
its error at some readings by no less than • 2 of a degi'ee, and in no part of the
scale by less than • 1 of a degree.
EXAMINATION OF INSTEUMENTS — PACKING. 01
of the Kew Observatory, Eichmoiid, Siirrey." The establishment hes
ten minutes' walk from the Richmond railway station. Any persons
ordering instruments from opticians may direct them to be previously
forwarded to Kew for verification, either to the above address, or through
the receiving establishment at the Meteorological OflBce, 63, Victoria
Street, Westminster, S.W.
Packing.
It is difficult to give general rules, because the modes of transport
vary materially in different countries. Inquiry should be made by the
intending traveller at the Eoyal Geographical Society's rooms as to the
kind of packing best suited for his special purposes and field of
exploration. The corners of all the instrument cases should be brass-
bound; the fittings should be screwed, and not glued; and the boxes
should be large enough to admit of the instruments being taken out and
replaced with perfect ease. Instrument makers are apt to attend over-
much to comi^actness, making as much as possible go into a small solid
box, which can easily be i3ut on a shelf; but this is not what a traveller
wants, bulk being rarely so great a difliculty to him as weight. Above
all, it is most important that he should be able to get at his instru-
ments easily, even in the dark. He should notice particularly the manner
in which the instrument is jilaced in its box, before taking it out, and in
the case of a theodolite, observe the positions of the verniers, and the object end
of the telescope ; attention to this will prevent much loss of time and
possible injury to the instrument. Moreover, a large, light box sufiers
much less from an accidental concussion than a small and heavy one.
Thermometers travel best when slipped into india-rubber tubes in a brass
casing. A coil of such tubing will serve as a floor, to protect a case
of delicate instruments from the effects of a jar. Horse-hair is of use to
replace old packing, but it has first to be prepared by steeping in boiling
water, twisting into a rope, and, after it is firmly set, chojDping it into
pieces. The hairs retain their curvature and act as springs. Instruments
travel excellently when packed in loose, tumbled cloths.
92
HINTS TO TRAVELLERS.
2. Instkuments, and theie Adjustments.
Compasses.
This instrument consists of a magnetic needle, A, balanced on a pivot,
B, carrying an aluminium ring, C, divided into 360°; it is graduated from
the south pole of the needle, — by west, north, and east to south again,
from QP to 360° ; the 0° is not shown on the ring, since it coincides with
360°. A prism, D, is fixed on one side of the box, E, mounted on a hinge-
joint, d ; it can be turned down when not in use, and is attached to a
plate, e, which slides up and down to suit the vision of the observer. In
the plate there is a slit through which the observer looks ; it has also an
Prismatic Compass,
arm with two dark glasses F, to protect the eye when taking a bearing
of the sun. On the opposite side of the box is a sight-vane G, having
a fine thread down its centre, and a mirror H, which slides on and ofi" as
required ; it can be used with its face up or down, so as to reflect images
of objects which cannot be directly observed. The sight-vane is also
fitted with a hinge-joint, and when shut down presses on a lever, which
lifts tlie needle off the pivot. In frout of the sight-vane there is a small
stud S, by pressing which with the finger the ring is brought to rest ;
COMPASSES. 93
it also serves to check the vibration of the needle. The box E has a
cover I, which fits either the top or bottom, in which latter position it
is shown in the drawing, and with it the instrument can be held when
taking an observation. The prismatic compass is frequently fitted to
screw on to a light tripod, with a ball and socket adjustment, and can
then be used with great accuracy either for taking bearings, or as an
angular measuring instrument.
Pocket Compass.
A prismatic compass is not suited for taking bearings, except
through the prism, on account of the reversal of the figures, and their
arrangement from the south point ; it will therefore be convenient, for
taking rough bearings, for the traveller to provide himself with a pocket
compass having a card of the size and pattern shown above ; it should
be made of aluminium, which is both light and strong. The compass box
should be fitted with a lever to throw the magnetic needle off its centre
when the compass is not in use, and the glass should be thick, flat
crystal. For night work a luminous pocket compass will be found
useful.
Observations with the Prismatic Compass : — To take an observation with
the prismatic compass, first adjust the prism by sliding it up and
94 HINTS TO TRAVELLERS.
down until the divisions on the circle are seen distinctly ; if a tripod
stand is used, screw the compass to the ball-and-socket joint, and
move the instrument until it is perfectly horizontal (the same pre-
caution must be taken if it is held in the hand) ; raise the sight-vane,
until ■ it is perpendicular ; look through the slit in the ])rism-plate,
and bring the thread of the sight- vane in a line with the object ;
wait until the magnetic needle comes to rest, and read the bearing
through the eye-hole in the prism-plate. A bearing thus taken shows
the angle which a straight line drawn from the observer, to the object,
makes with the magnetic meridian (called the magnetic bearing).
To get the true bearing the magnetic variation must be applied as
follows : — If the variation is east add it to the bearing, if west subtract it,
and the result in either case will be the true bearing. Thus : the magnetic
bearing of an object was 160^ and the variation 20"^ east, then 160° + 20°
= 180°, the true bearing: the bearing of an object was 160° and the
variation 20° west, then 160°— 20° = M0°, the true bearing; but since
the magnetic needle will be affected equally by variation within certain
limits of time and space, the difference of the bearing of any two objects,
taken from the same station, will be the angle subtended by them, as the
difference in their azimuths will not be affected by the variation.
Where i)ossible, the bearings should be taken at both ends of a base, or
line of bearing, the mean of which will be the correct bearing. When
the sun's azimuth or amplitude has to be taken, one of the dark
glasses should be placed before the slit in the prism-plate, and the
mirror should be moved on the sight- vane until the reflected image of
the sun is seen in the mirror through the slit in the prism-plate; the
bearing is then taken in the manner before described. Great care must
be observed when using this instrument to avoid all magnetic rocks, as
they may so affect it as to render bearings taken in their vicinity useless.
Eypsonfietrlcal Apparatus.
The boiling-point apparatus consists of a thermometer, A, generally
graduated from 180° to 215°* ; a spirit lamp, B, which fits into the bottom of
* When it is intended to be used at very great elevations, the thermometers
will have to be specially constructed with extended scales.
HYPSOMETRICAL APPARATUS.
95
a brass tube, C, that supports the boiler, D ; and
a telescopic tube, E, which fits tightly on to the
top of the boiler. The thermometer is passed
down the tube, E, from the top until within a
short distance from the water, wliich it should
never touch, and is supported in that position
by an india-rubber washer, F. The steam passes
from the boiler up the tube, E, and escapes by
the hole, G. To pack this instrument for tra-
velling, withdraw the thermometer, and put it
into a brass tube, lined with india-rubber, having
a jiad of cotton-wool at each end ; take off the
tube, E, shut it up, and put the small end into
the boiler, D, which it fits, then withdraw the
spirit lamp, B, screw the cover over the wick
and replace it in C. The whole of this apparatiis
fits into a circular tin case, 6 inches long, and
2 inches in diameter.
To use the hoiling-2)oint thermometer: — Take
the apparatus to pieces, pour some water into
the boiler, D, about one quarter full is quite
sufficient ; then put the instrument together as
shown in the drawing, taking care that the
thermometer is just clear of the water, and
light the spirit lamp ; as soon as the water
boils, the steam ascending through the tube, E,
will cause the mercury to rise ; wait until the
mercury becomes stationary, and then read the
thermometer ; at the same time, take the tem-
perature of the air in the shade with an ordinary
thermometer.
If the traveller is visiting a region where the
elevations are very great, he should, when pur-
chasing this apparatus, see that the thermo-
meters are capable of registering a greater height
than those which are usually supplied, and that
the lamp is large enough to hold a good supply
An
IP^
P
96 HINTS TO TRAVELLEES.
of spirit, as it is a common fault to make it too small. A screen,
which may be made of tin to fold up, is most useful to place on the wind-
ward side, and at a very low temperature is almost indispensable, as the
heat is otherwise carried off too rapidly for the water to boil properly.
The Aneroid.
The general appearance of the aneroid is so well known that it re-
quires no special description; it is an excellent instrument for laying
down contour lines ; but for absolute heights it should be checked by the
boiling-point thermometer, because its index error is apt to change ; when
thus checked it is a valuable instrument for measuring heights up to
8000 feet, but at greater elevations it is generally unreliable. It should
be sent to Kew Observatory to be tested, and have its errors determined
before and after it has been used by a traveller for the purpose of measuring
heights, and during the journey every opportunity should be taken of
comparing them with mercurial barometers.
In the majority of cases, aneroids, even when they have been in the first
instance correctly graduated, do not read accurately against the mercurial
barometer at diminished pressures, and will be found almost always to
possess more or less considerable plus or minus errors. These errors are
tolerably constant in good instruments, though they are frequently
considerably augmented when low pressures have been experienced for a
length of time.
Aneroids should be treated with almost as much care as chronometers,
and shoiild not be allowed to dangle about the person, or to be shaken up
in pockets. If the watch size is employed, they can be conveniently
carried in extra watch pockets.*
Measurement of Heights with the Aneroid : — To measure the difference
in height between two stations, two instruments should be used, and
the readings taken simultaneously at both stations ; but it frequently
happens that this is impossible, in which case the observations should
be taken in the following manner : — Take the reading of the aneroid
and the temperature of the air, in the shade, at the lower station ; repeat
* On this subject the traveller will do well to read Mr. E. "Whymper's book,
' How to use the Aneroid Barometer.' J. Murray, London.
BAROMETERS. 97
this at the upper station, and again at the lower station on returning to
it, but before taking this last reading a short time should be allowed
to let the aneroid take up its proper working, as a descent will always in
a greater or less degree affect it.
In observing with the aneroid, the instrument should always be in the
same position, as, for instance, with its face vertical; merely altering
the position affects most aneroids with a very sensible difference of
reading.
On leaving a station to which it is not intended to return, the reading
of the aneroid should be taken, and the temperature in the shade ; during
the day's journey the difference between any reading and that taken
at starting will approximately give the difference of height unless there
has been some atmospheric change. This is only a very rough way of
ascertaining whether a party, passing through a hilly country, has ascended
or descended; for the accurate method of computing the difference of
height of two stations, see examples (p. 318).
The Boylean-Mariotti Barometer.
This instrument consists of a short centre glass tube, a lower open air
tube with diaphragm joined to it with a vulcanite covering for insulation
and a brass tube which covers the glass tube, and on which the graduations
and figures are engraved. Attached to this is a cistern filled with mercury,
which has a tap and a coarse screw adjustment. The total length of this
instrument is from twelve to fifteen inches, but for convenience of
carriage the cistern may be detached at pleasure, and carried separately.
To use the instrument : — At a convenient height for the eye, suspend
the barometer freely by a string tied to the brass ring at the top of the
instrument. Then turn on the tap of the cistern containing the mercury,
and, keeping the barometer steady and in a perpendicular position with
the left hand, with the right commence to turn the screw at the bottom
of the barometer from left to right, at the same time looking through the
small narrow slot just above the larger opening in the lower part of the
barometer. After turning the screw for some time, the mercury will be
seen to rise in the tube of the barometer, and, though much slower, to be
filling the lower part of the instrument, seen through the larger opening.
When the mercury has risen for a considerable height, watch carefully
H
Georges Mercurial Barometer.
BAROMETERS. 99
through the smaller and upper slot, and continue to turn the screw slowly
until a bubble is seen in this slot, taking care to keep the barometer
steady and in a perpendicular position. Let the top of this bubble just
reach the upper part of the slot, and then bring the lower edge of the
upper or lower vernier (whichever is most convenient) on a line with the
top of the mercury in the barometer tube, and take the reading in the
ordinary manner. The reading should be taken directly the haromtter is set,
as it is only true at that instant, and the barometer should not be handled
more than is absolutely necessary, as the heat of the hand alters the
temperature of the instrument, and consequently the reading.
Captain George's Mercurial Barometer.
To Fill : — Spiral Cord Method, Take the tube out of the tripod stand,
unscrew the short part of brass tube and take out the tube; insert
it carefully into the cistern with a screw-like motion through the rubber
plug until the end of the tube is opposite the mark in the middle of
the cistern. Then screw on the smaller half of the brass tube and pass
it down through the top of the stand (cistern uppermost) until it rests
on it. Take off the bottom of the cistern, and thrust the feather end of
the spiral cord down to the bottom of the tube. Now take the filterer
and pour the mercury down the orifice of the tube until the cistern and
tube are filled. Give the spiral cord circular motion from right to left
until it works itself out of the tube, when fill in mercury up to the top
of cistern.
Screw on the lower stopper tight, take the barometer out of the stand,
and invert it : try if it gives a sharp metallic click-like sound : if it does
there is a perfect vacuum ; if it does not, there will be air in the tube, and
the whole process must be repeated. Pass it upwards throiigh the centre
of the tripod stand, guiding the projecting arms through the notches,
and giving it a quarter turn, land it in its place, where it will swing
perpendicular.
Let it rest a few minutes, read off the upper scale first and then the
lower ; their difference is the true reading, if the zero is immersed in the
mercury ; but their sum if the zero is above the mercury in the cistern.
To Empty the Barometer. — Screw down the flange, and thus secure the
mercury in the cistern.
H 2
100 HINTS TO TKAVKLLERS.
Take the barometer out of the stand. Keverse it carefully, and unscrew
the lower cap, tapping it gently to shake off the globules into the cistern.
Empty out the mercury into the wooden box, lioldirig the lore-finger
across the lower part of the orifice of the cistern. This pi-events its rush-
ing out too quickly, and avoids spilling the mercury. Place the empty
barometer in its stand.
Pour the mercury from the wooden box into the iron bottle. Secure it
by the screw plug.
Clean the tube and cistern, inside and out, and it will be ready for
re-filling again, or being stowed away in its stand and case.
The Sextant.
The principle on which the sextant is constructed is this : — that the
angle between the first and last directions of a ray which has suffered two
reflections in one plane, is equal to twice the inclination of the reflecting
surfaces to each other. The arc on which the angle is measured must
therefore be divided into double the number of degrees which properly
belong to an arc of the same extent. With this instrument we can
measure the angle between two objects, in whatever direction they may
be placed, provided the angle is within its limits.
With the aid of the following figure, the difierent parts of the sextant,
with their names, may be distinguished.
A is a plane mirror called the index glass ; it is set in a frame, and is
fixed on a centre perpendicular to the plane of the instrument ; it moves
with the index bar B C, the end of which C slides over the arc E F, which
is graduated (on an inlaid plate of platinum or silver) from 0" to about
140^ ; each of these degrees, according to the radius of the iustriiment,
is divided into 10' or 20', and these are subdivided by the vernier D
into 10" or 20"; these divisions on the arc are continued a short dis-
tance on the other side of zero (0^) towards F, forming what is termed
the arc of excess. The index is secured to the arc by a damp screw G,
which must be released when the index has to be moved over a large
portion of the arc. In order to obtain the slow motion necessary for
the accurate measurement of an angle, a tangent screiv, H, is fixed to
the index, but does not act until the index is fastened by the clami) screw.
I, is a fixed plane glass, the lower half of which, next to the frame
THE SEXTANT.
101
of the iustrument, is silvered, and the upper half left clear. It is called
the horizon glass, and must be perpendicular to the plane of the instru-
ment, in such a position that its plane shall be parallel to the plane of the
index glass when the index points to zero (0^) on the arc; it is adjusted
by means of the screw K*.
L and M are coloured glasses of different depths of shade, any one or
more of which can be turned down in front of either the index or horizon
glass to moderate the intensity of the light before reaching the eye,
* The form and position of this screw differs very mucli in different sextants;
in many, the adjustment is made by two small screws bearing on the back of the
glass.
102 HINTS TO TRAVELLER8.
when a bright object, such as the sun, is observed. N is a microscope
which is carried on a moveable arm O, and can be adjusted to read the
divisions on tlie gradiiated arc and vernier. The telescope T is carried
by a double ring, E, so constructed that it furnishes means of adjusting
the linfe of collimation : this ring is attached to a stem S, which can be
raised or lowered until objects seen by reflection, and directly, appear of
the same brightness. U is the handle which is sometimes fitted with a
brass centre, having a hole in it, to admit of its being fastened to a stand.
Adjustmen ts of the Sextant.
The principal are the following : —
1. To make the index glass perpendicular to the plane of the
instrument.
2. To make the horizon glass perpendicular to the plane of the
instrument, and parallel to the index glass when the index points
to zero (0°) on the arc.
3. To make the axis of the telescope parallel to the plane of the
instrument, in which the index moves.
1st Adjustment. — This adjustment rests with the maker; and being
once made cannot be deranged, except by a fall or blow, against which
every precaution must be taken. The instrument should, however, be
occasionally verified by the observer in the following manner: — Set the
index at 60^; and, holding the sextant in the left hand, with the right
move the index gently backwards and forwards, looking, as you do so,
obliquely into the index glass; then, if the image of the arc in the mirror
appears in perfect continuation of the arc itself, the adjustment is perfect;
when this is not the case, the index glass is out of adjustment. If the
derangement is great, the sextant is for the time being useless ; if small,
it may possibly be remedied by means of certain screws sometimes
fitted at the back of the glass ; but it is better to leave it alone, as an
inexperienced observer would most probably only make it worse. A
man who has a thorough knowledge of his instrument can take off
the frame, and, by hammering and tinkering, get it put square and
straight ; in replacing it, wedging it up, if necessary for perfect ad-
justment, with small folds of paper. A bad derangement may be put
ADJUSTMENTS OF THE SEXTANT. 103
to rights in this way; but it is, very evidently, a thing not to be rashly
attempted.
2,nd Adjustment. — Having screwed in the telescope, look through it and
the horizon glass at the sun, or still better, a star, and move the index
backwards and forwards, on each side of zero (0°), when the reflected
image of the object ought to pass exactly over the object itself. If it does
not do this, but passes either to the right or left of it, the horizon glass
is out of adjustment, and its adjusting screw must be gently turned
until the reflected image does pass directly over the object itself.
Zrd Adjustment. — Screw the telescope firmly into the collar, turn the
eye-piece until two of the wires in the focus of the telescope are parallel to
the plane of the instrument. Select two stars, not less distant from each
other than 90^, bring them into exact contact at the wire nearest to the
plane of the instrument ; fix the index, and move the instrument so as to
throw the images upon the upjier wire ; if the contact remains perfect
the adjustment is perfect : if not, it must be rectified by the two opposing
screws in the double collar, taking care to slacken one before tightening
the other: the one to slacken is that on the side towards which the
contact opens.
Index Error. — When the index is set at zero (O'^) on the arc, the
horizon and index glasses should be parallel, and the two images of a
distant object, as a star, should exactly coincide; when this is not the
case, it may be remedied by turning a screw in the mounting of the
horizon glass. If this adjustment is not made, there will be an error
in the place of the beginning of the graduation; this is called the
Index Error; its amount is easily determined, and, as it affects all angles
alike, it is usual to admit the existence of this soi;rce of error, and apply
correction for it, in preference to making the adjustment.
Tojind the Index, Error by a Star. —Set the index at zero (0''), screw in
the telescope, and, with the tangent screw, make the two images of a
star, as seen through the telescope, coincide ; then the reading on the arc
will be the index error. Subtractive when the reading is to the left of
zero, additive when to the right.
By the Sun. — Clamp the index at about 30' to the left of zero, and
looking through the telescope at the sun, the images will be seen nearly
in contact ; make tliis contact perfect with the tangent screw, take the
reading, and call this " on the arc " ; next, set the index, at about 30' to
104 HINTS TO TT{AVETJJ':TJS.
tlio riglit of zero, and make tlie contact of the two images perfect as
before, take tlie reading, and call it " off the arc " : half the difference
of these two readings is the Index Error.
Examples.
On the arc.. .. .. 33 10 On the arc. .. .. 29 30
Off the arc. .. .. 29 30 Off the arc. .. .. 33 10
2) 3 40 2) 3 40
Index corr. suhtract =1 50 Index corr. add =1 5 c
As a check on this observation, for inexi^erienced observers, it may be
noted that one-fourth of the sum of the readings on and off the arc
ought to be the sun's semi-diameter, as given in the 'Nautical Almanac'
Centering Error. — In addition to the foregoing, every sextant is
liable to errors caused by: —
1. The centre of the pivot of the index-bar carrying the vernier
not being identical with the centre of the arc.
2. Imperfect graduation of the arc.
3. Flexure of the whole instrument caused by irregular expansion
under the heat of the sun.
4. Shocks or blows which may cause bending of parts of the frame,
or of the index bar, and thus cause eccentricity between the
vernier and arc.
These errors are generally included in the term " centering error."
The original error included in [1] and [2] can be determined at Kew,
where apparatus for the purpose is established. Those under [3] and [4]
are manifestly variable.
In a good sextant the original error should be small, amounting only
to a few seconds, but instruments are made which have much larger
errors, and as these are enormously multiplied in their effect in some
observations, as e.g. lunars, a traveller should always have this error
determined before leaving England.
THE BOX SEXTANT.
lOr
The Box or Pocket Sextant.
The box sextant is constructed on the same principle as the larger
sextant ; it is enclosed in a brass box, varying in size from 3 to 4 inches
in diameter, and from an inch and a half to two inches deep.
This instrument is very portable, light, and easily adjusted. It is
more correct than the compass for measuring horizontal angles, as an
angle can be read to within 1' by means of the vernier on the graduated
arc. It can also be used on horseback, and in all sorts of weather,
and, when not required for use, can either be carried in the pocket, or
slung in a leather case over the shoulder.
The instrument, as shown in the drawing, is ready for use : the cover, A,
is screwed on to the lower part of the instrument, and serves as a handle
when taking an angle ; B is a graduated iirc, divided into degrees and
half degrees; C is the index har, having a vernier at the end, divided to
read the angle to 1' ; D is a milled, screiv by which the index bar is
moved ; attached to the end of the index bar, on tlie inside of the box,
is the index glass, E ; the horizon glass, F, is also inside the box, one half
of which is silvered ; G is a small magnifying glass attached to the
top, to enable the observer to read the angle more clearly; there are
106 HINTS TO TRAVELLERS.
dark glasses, to be iised when observing the sun, not shown in the
drawing. H is the adjusting screw, which is screwed into the top for
safety ; it is made with a square, like a watch-key, and when required
for use has to be removed from the position shown in the drawing; I is
the telescope, which should be fitted at the eye-end with a revolving disc N,
which is provided with shades of different intensity, to be used with the
artificial horizon ; in taking angles the instrument can be used without
the telescope, by drawing the slide, L, over the hole from which the
telescope has been removed.
Adjustments : — Having set the index at zero (0~) on tlie arc, select some
object that is sharp and perpendicular, as far distant as possible, to be
seen clearly; then, holding the instrument in a horizontal position, look
at this object through the eye-hole, and, if the reflected image coincides
with the object seen directly, the adjustment is so far correct. Then hold
the instrument the contrary way, or vertical, look at some object that is
level, and if the reflected and real objects are seen in a straight line this
adjustment is also correct ; but when this is not the case the adjustment
must be made by taking out the key, H, placing it in one of the keyholes,
M, either on the top or side of the instrument, and turning it gently
until the reflected image of the object coincides with the object seen
directly. If the reflected image reqiaires moving up or down, the key
must be inserted on the top of the instrument, but when it has to be
moved to the right or left the key must be inserted at the side.
These adjustments can be made, when no available objects, such as
those mentioned, are in sight, by the sun, using a suitable shade. Set the
index to zero, and move it until the reflected and direct images coincide ;
if the index then points to zero (0^) the instrument is in adjustment, if
not, make the coincidence with the key as above described. A bright
star may be used in preference to the sun, in which case no shade will be
required.
The adjustment by a terrestrial object is here given to meet the case of
an instrument having to be adjusted in the day-time when the sun is not
visible. Care should be taken when purchasing a box sextant to see that
the maker has made the box wide enough to admit a finger to wipe the
glasses, as dull reflectors much increase the ditficulty of observation.
ARTIFICIAL HORIZONS. 107
Tlie Artificial Horizon.
The artificial horizon is a reflector, the surface of which is perfectly-
horizontal ; it is used in combination with the sextant for observing
altitudes. Though the principle of all is the same, there are several
forms of this instrument, the most common, as well as the best, being
a small shallow trough, containing pure, clean quicksilver,* which
reflects the image of a celestial body. This is protected from the
disturbing efi'ects of the air by a roof, the two sloping sides of which
are made of glass plates accurately ground to true planes : these must
be carefully examined to see that they are of uniform thickness and
density. Should the traveller have the misfortune to break one of his
glasses, and rej^lace it by one not tested, he must be careful to reverse
the roof between two observations, or once in a set. Captain George's
horizon, in which a glass plate floats on the surface of the mercury, is
in some respects more convenient ; but it is more liable to errors arising
from any disturbance communicated to the mercury by wind.
Another form of artificial horizon is the black plate. It generally
consists of a plane of black plate-glass set in a metal frame, and levelled
by a bubble. This form answers fairly well in the day-time, when the
sun is the object observed, but at night there is so much loss of light
with the black plate that it becomes extremely difficult to use in star
observations. In order to overcome this diflBculty, artificial horizons of
tliis class have been constructed with a brass ft-ame containing a black
plate on one side, for day observations, and a silvered mirror on the
other, for night. To the frame are attached fixed levels, by which it
can be brouglit to a true horizontal position. This is a very portable
instrument, but its use can only be recommended in the absence of
* If the quicksilver is not pure it gives an imperfect reflection, and its level
is apt to be untrue. The quicksilver of commerce is generally mixed witli lead,
bismuth and zinc, which have to be dissolved out of it by nitric acid ; it may,
however, in case of emergency, be rendered serviceable by shaking it for some
considerable time in a bottle with a little powdered sugar, or even sand, and
afterwards straining it through a piece of fine linen or chamois leather, but it is
a troublesome and not very satisfactory process.
108 HINTS TO TRAVELLERS.
a mercurial horizon, and when the glass used in its composition has
been ground into a true plane, and tested at Kew Observatory in the
same manner as a sextant index-glass. Every care must be taken to
level, this instrument accurately, or all observations taken by means of it
will be of no value. Any form of artificial horizon that is used should
be kept clean and free from dust.
Should the artificial horizon be broken or lost, a substitute may be
formed by treacle or other viscous liquid, or even, in calm weather, by
water, in a tray or basin.
Sextant- Stand.
Though sextant-stands vary considerably in the manner in which they
are constructed, the object in all cases is the same, viz. : — to provide a
means by which the sextant can be fixed in any position convenient
to the observer, and also to give that steadiness, so important in sextant
observations, which is often wanting in the traveller's hand after a hard
day's journey, or an attack of fever. Gary, 181, Strand, has succeeded in
making a very convenient form of this instrument, and one that is in
many respects superior to the old form. The only adjustments are to
place the stand as level as possible, and in sucli a position that the plane
of the sextant shall be in the plane of observation.
Transit Theodolite.
The following are the names of the various parts of this instrument to
which reference is made in the remarks on its adjustments.
A is the Vernier-plate ; it is furnished with two vernitrs, a, 180^ apart,
graduated to read with the vernier, to 10". B is the Lower-phte ; it is
gradiiated into 360°, each degree being again subdivided into 10', and can,
with the vernier, be read to 10". These two plates combined are called
the Horizontal limb, and revolve independently of one another, biit when
required can be made to move together by tightening the Clamp-screw C;
the slow motion is obtained by the Tangent-screw D ; the lower plate has
also a Clamp E, and a Tangent-screw F. G G is the Tribrach System.
H is the Horizontal axis. There are three Levelling screws, 1, 1, I. K is
the Tripod, on which the instrument is firmly screwed ; underneath, in the
109
Transit nieodolitc.
110 HINTS TO TRAVEI;LERS.
centre, there is a hook (not shown in the drawing) from which to suspend
a plummet in order to indicate the exact position where the station peg
is to be driven into the ground. The vernier-plate carries a compass li
in its- centre between the supports of the Telescope ; it is graduated into
360°, and fitted with a screw M to lift the magnetic needle off its centre
when not in use. The two Frames N N carry the hcarin<js V for the
telescope, with its level P, and the graduated circles K, called the Verti-
cal limb, with its two verniers S S, and Microscopes m m. The vertical
limb is graduated from 0° to 90"^ through one quadrant, then again
from 90° to 0° in the next quadrant, and so on round the circle ; the
degrees are subdivided into 10', and, with the verniers, read to 10". The
horizontal axis of the telescope is formed of two cones, the larger ends of
which are attached to the telescope tube, while the small ends, called the
Pivots, p, are ground into two perfectly equal cylinders; the pivot which
does not carry the vertical limb is pierced, and allows the light of a lamp
to fall upon a small reflector (not shown in the drawing) which is screwed
into the centre, on the axis of the telescope, and inclined to it at an angle
of 45°, by which means the light is thrown directly down the telescope,
and illuminates the fine threads, or web, attached to a Diaphragm inside
the telescope, which is kept in its place and adjusted by the screws y y,
of which there are four. The Index-bar^ x, is fixed in its place by the
Clip-screws, z z. The vertical-limb is furnished with a Clamp and a
Tangent-screw, w; d d are Levels at right angles to one another ; / and h
are the small lantern and its holder, which fits into a slot in the frame
on the side opposite to the vertical limb ; g g are capstan-headed screws
for adjusting the telescope level. The telescope is brought to focus by a
milled screw (not shown in drawing) near the object-glass ; a diagonal
eye-piece is also supplied with the instrument, and is extremely useful
in astronomical observations ; i is a capstan-headed screw used in ad-
justing the axis of the telescope.
A very useful addition to the transit theodolite is to provide it with a
pair of micrometers in the eye-piece, by means of which the distance
between the observer and staff of known length can be measured in
the manner shown (page 122), in addition to which they increase the
efficiency of the instrvmaent for astronomical observation.
THE TRANSIT THEODOLITE. Ill
Adjustments of the Theodolite.
Parallax. — This adjustment is made by moving the sliding tube of the
eye-piece until the threads of diaphragm are seen sharply defined against
the sky, and then by pointing the telescope at some object, and bringing
it to the proper focus by the milled-head screw near the object-glass. To
test the accuracy of this adjustment direct the telescope on some well-
defined object, about as far distant as the points to be fixed. Intersect
this object accurately by using the tangent screws, with the centre of the
threads in the diaphragm. Now move the head laterally as far as the field
of view will admit, at the same time watching the intersection of the
object with the threads. If the object remains stationary on the threads,
parallax has been eliminated; but if it does not, the parallax must be
removed by turning the focussing-screw until the object remains stationary
in whatever position the head of the observer may be.
Adjustment for Collimation. — Set the instrument as nearly level as can
be done with the eye, then clamp the lower plate B, and, having un-
clamj^ed the vernier-plate A, direct the telescope on some well-defined
object, and bring it into coincidence with the point of intersection of the
threads of the diaphragm ; take the reading on the horizontal limb
A B, suppose it to be 20^, then move the vernier-plate. A, half-round, turn
the telescope over, and again intersect the object, taking the reading on
the horizontal limb, suppose 200^ 2' 30", take the difierence between this
and the first reading + 180' (which in the present case would be 200°),
and tlie difference would be 2' 30" ; halve this difference, and subtract it
from the second reading, when it is greater than the first reading -I- 180°,
and add it when it is less ; this is the mean reading ( = 200'^ 1' 15") ; set
and clamp the instrument to this mean reading, and intersect the object
by means of the capstan-headed screws y y, which move the diaphragm,
taking care to loosen one before moving the other. Eepeat this operation
until the readings taken with the instrument in these two different
positions, face right and face left, differ from one another by 180'.
To make the vertical and horizontal wires respectively vertical and
horizontal. — As these wires are fixed in the diaphragm by the maker so
as to cut each other at right angles, it follows that to adjust one wire is
to adjust both, and this may be done by either of the following methods,
112
HINTS TO TRAVELLERS.
the latter beinp; capable of the greater accuracy : — 1st Method. — Level
the instrument with care, and intersect any small, well-defined point
with the vertical wire, and see if it continues bisected along the wire
when the telescope is moved in a vertical plane. If this is not the case
the capstan-headed screws y y must be slackened suflBciently to allow the
diaphragm to be revolved until this condition is secured, when they
must again be tightened. It will now be found that the horizontal wire,
if properly placed by the maker, will continue to bisect an object on
which it has been placed when the instrument is turned in azimuth.
2nd Method. — Set up the theodolite as at T (see figure below) and level
it carefully. Set up a stake, with a mark on it, at such a distance that the
mark is distinctly visible, as at A. Ti^rn the telescope on it and accurately
cover the mark with the intersections of the cross wires in the diaplu'agm.
and clamp it in azimuth. Next turn the telescope over and set up
another stake, with a mark on it, at the same distance from the instru-
ment as A, and move the stake until the mark on it is accurately covered
by the intersection of the wires. If the collimation is in adjustment the
stake will be at B, but if not it will be in some other position, such as C.
In order to test this unclamp the vernier plate and turn the instrument
half round, and, ivithout turning the telescope over, sight to the mark on A,
and clamp the instrument in azimuth, turn the telescope over, and if the
collimation is out of adjustment it will point to the position D in the
figure as far to the right of B as C was to the left. This shows that the
collimation of the telescope is not perpendicular to its horizontal axis.
In order to correct this, measure the distance from C to D and set up a
stake at the middle point B, and and another stake midway between B
and D, at E. This will be one-fourth of the distance between C D, the
ADJUSTMENTS OF THE THEODOLITE. 113
amount of adjustment required, and must be made by moving the vertical
wire to the right or left by the capstan-headed screws y y. The telescope
will then be on the line E F, both of which points are respectively equi-
distant from A and B, so that if the intersection of the cross-wires be
accurately placed on a mark on the staff at B and turned over, it will
strike the mark on the staff A, and the adjustment for collimation in
azimuth will have been made ; this is, however, seldom done at the first
trial, and the operation has generally to be repeated. In both of these
cases the adjustment has been made by the vertical wire.
Adjustment of the Telescope Level. — Level the instrument carefully on
the azimuth axis H, by means of the levels d d on the horizontal limb
A B ; next, take a pair of verticals, i.e. on faces right and left, to any well-
defined terrestrial object ; set the vertical circle E to the mean of these
readings, and clamp it ; now intersect the object, using the two screws z z,
which clip the limb of the vertical circle x, to the stud in the frames N N,
and not the tangent-screw W ; then repeat the process as before.
Eemember that after each pair of readings the mean is to be taken, and
the object intersected by the clii^-screws z z, and not by the tangent-screiu
W; and when the readings on the right face agree with the left face,
the index error will be 0. Next clamp the vertical circle E at 0^ 0' 0",
and bring the bubble of the telescope level to the middle of its run
by means of its adjusting screws g, and the level will be in adjustment.
With regard. to the clips z z, which keep the vernier s s in position,
never unscrew both after the adjustment has been made; but to release
the vertical circle before putting the instrument into its box, unscrew
only one of the clips, and mark it so that it may be known, and use
this same screw when setting up the instrument again. The other clip-
screw should never be touched ; and, indeed, it would be an improvement
if one of the clip-screws were fitted with a lock-nut, by which it would
be kept in its proper place, and at once be distinguished from the working
screw.
Adjustme7it of the Horizontal Limb. — Tighten the clamp-screw E, unclamp
the vernier-plate A, and turn it round until the telescope is immediately
over one of the parallel plate-screws I I ; bring the bubble in the tele-
scope level P to the middle of its run by turning the tangent-screw W ;
turn the vernier-plate 180'', so as to bring the telescope again over the
same screw, but with its ends in a reverse position. If the bubble of
I
114 HINTS JO TRAVELLERS.
tlic telescope level does not rem.iiii in the mifldlc of its run, bring it back
to tluat position, halfhy one of the parallel plate-screws I I, and half by
the tangent-screw W. This operation must lie repeated until the bubble
remains accuralely in the ceuti-e of its run in both positions of the tcle-
Rcopo; now turn the vernier-plate A until the telescope is directly over
another of the parallel plate-screws, and l)ring the bubble to the middle
of its run by turning this screw.* The bubble should now retain its
position, while the vernier-plate is turned completely round, showing
that the internal azimuth axis, about which it turns, is truly vertical.
Clamp the vernier-plate to the lower plate by turning the clamp-screw C,
and loosen the clamp-screw E ; move the instrument round its azimuthal
axis, and if the bubble retains its central position during a complete
revolution, the external azimuth is truly parallel with the internal;
"when this is not the case, the instrument must be sent to the maker, as
this fault cannot be remedied by the traveller.
It is most probable that the levels on the vernier-plate will now be
found out of adjustment, and the bubbles must be brought to the middle of
their run by turning the capstan-headed screws at the end of each of them.
IlorizontaUty of the Axis of fhe Teh-scope. — This is to be tested by the
striding-level, which is supplied with the instrument. Apply it to the
pivots y, and if the bubble is not in the middle of its run, bring it to
that position by turning the capstan-headed screws t Tinder the moveable
bearing. If there is no striding-level, this adjustment can be tested by
observing a long plumb-line, first making the intersection of the threads
in the diaphragm coincide with this line, and then, if the point of
intersection moves along the line when the telescope is elevated or
depressed, the adjustment is perfect ; if not, it must be made to do so
by turning the capstan-headed screws.
The adjustments can be tested in the following simple manner : — With
the plummet supplied with the instrument, find the exact central spot
over which the instrument stands ; drive a peg into this place, and fasten
a cord to the peg ; now go in any directiou, for say 40 feet, and drive in
another peg, stretch the line tight between these pegs, and then intersect
the line with the threads in the diaphragm, clamp the horizontal plates,
* If the theodolite is fumislied with four parallel plate-screws, they must
always be used in paira.
ADJUSTMENTS OF THE THEODOLITE 115
and if the intersection remains perfect while the telescope is moved on its
axis the adjustments are so far correct. Next move the outer peg about
90" (witli the same radius) from its first position, and again drive it into
the ground and draw the line tight as before ; nncJamp the vernier-jDlate,
keeping the lower plate clamped, and rej^eat tlie previous operation ; if
the point of intersection of the threads in the diaphragm keeps on the line
while the telescope is moved on its axis, the theodolite is in adjustment,
if not, the adjustments should be gone over again.
Tlic Vernier of the Vertical Limb. — When the foregoing adjustments have
been made, set the vernier of the vertical limb to 0^ 0' 0", and bring the
bubble of the telescope level to the middle of its run by turning the clii?
screws. The instrument will now be in adjustment and ready for use.
All first-class instrument makers are very careful, for the sake of their
reputation, to see that the theodolite is in perfect adjustment when it
leaves their hands, and, with the careful treatment which this instrument
should always receive, is not likely to get out of order; it is, nevertheless,
necessary from time to time to test these adjustments.
Observations with the Transit Theodolite sliould always be taken
in pairs, with the vertical circle first to the right and then to the left,
and the mean of results should be taken. When a diagonal eye-piece
is used for observing altitudes of the sun, the lower limb has this ap-
y^B^. When observing
iiearance — M-^^ — 'iii<-l the upper limb this, upper
■^ lqwehIlimb. ^ ^ 7n
13
altitudes of the sun with the inverting telescope, it must be remem-
bered that what appears to Ije the lower limb is really the upper.
th
„»:_ltl_
UPPER LIMB.
and '-°*"
a
UMB. . Where the direct telescope is used the
reverse is the case.
An improved form of transit theodolite, made by Elliott Bros.,
in which the level A is carried on the vernier arms instead of being
attached to the telescope, is shown p. 116. The magnetic needle B
I 2
116
HINTS TO TRAVELLERS.
is also attached to the instrument in a different manner, being in all
respects similar to the one used with the plane tabic, and is described
page 126. This is so constructed that it can be attached, by the
hooks CC C, to the under part of the instrument. The adjustments of
ADJUSTMENTS OF THE THEODOLITE. 117
this instrument are identical with those previously given for the more
common form of transit theodolite, with the exception of that for the
vernier arm level A, which is adjusted in the following manner : — First
set the instrument carefully by the levels on the vernier plate, and then
by means of the dip screws Z Z bring the bubble of the level, A, on the
vernier arms to the middle of its run. Next unclamp the vertical circle
and place the intersection of the hairs in the telescope, accurately, on
some well-defined distant object, take the reading of the vertical circle,
unclamp the instrument, turn it through 180°, turn the telescope over;
again cover the object with the intersection of the telescope hairs, and
take the reading of the vertical circle. The meau of these two readings
(face right and face left) will be the true reading to which the vernier of
the vertical arc must be set, by the tangent screw W. Then by means of
the chp screws ZZ again cover the object with the intersection of the
telescope hairs. This operation should be repeated until the reading of
the vertical circle is the same with the telescope in both positions. When
this has been accomplished, the bubble of the level on the vernier arms
must be brought to the middle of its run by the capstan-headed
screws Y Y at the end of the level-tube.
The magnetic needle is used in the following manner : — Attach it
underneath the vernier plate by means of the hooks C C C provided for
that purpose. Set the vernier of the horizontal plates to 360^, and then
keep the upper plate clamped. Unclamp the lower plate and turn the
whole instrument round until the magnetic needle points nearly to the
central division in the box, clamp the lower plate, and make the needle
point exactly to this division. The telescope will now point to magnetic
North, and if the ujiper plate is undamped and turned on to any object,
its magnetic bearing can be read from the verniers. Care must, of course,
be taken to keep the lower plate firmly clamped.
F is the striding level which can be used in levelling the transit axis.
G is the lantern which is placed on the stand H after it has been fixed to
the standards, and is used to illuminate the threads of the diaphragm,
through the hollow axis K, when star observations are being taken.
118 HINTS TO TIIAVFJ,T>ET^S.
Everest TlieodoUte.
This iiistiument has distinctive features, as shown by the figure, p. 119.
The horizontal limh L consists of one plate only, on which the degrees
are graduated ; the verniers V are at the end of bars radiating from the
centre ; and another bar carries the damp C and the tangent-screw for
the verniers. At S, are shown the clamp and rIovj- motion screw of the
horizontal limb. The vernier bars are connected with the upper portion of
the instrument carrying the telescope NN, and vertical limh MM, which,
turning upon the same centre, show the angle traversed by the telescope.
The tripod support B is provided with foot screivs p p p. It
will be seen by the figure that the telescope and vertical limb are
supported in a manner very similar to the transit theodolite, the
horizontal axis connected with the telescope resting on two supports Y,
only one of which is seen in the drawing. These are supported by a
flat horizontal bar E, to which is attached a spirit level, only one end
of which is seen in the drawing. This level is for adjusting the axis
horizontally ; and, this being accomplished, the vertical arc M '^l,
attached to the telescope, moves with it in a vertical plane.
Adjustments of Everest Theodolite {furnishfd by Captain Pratt, B.E.).
1. Correction for Parallax. — Adjust the eye-piece to distinct vision of
cross hairs, and correct for parallax by means of the object-glass screw,
2. Making the Level of the Horizontal Lirnl) parallel to that Limb. —
Clamp the tribrach to axis, and unclamp the horizontal vernier-plate
Move the latter so that the horizontal limb's level may be over, or parallel
to, two foot-screws. By means of these screws bring the bubble to the
centre of level. Turn the vernier-plate lound 180-, and correct the level's
error half by the foot-screws and half by the level's capstan-headed
screws. Turn the vernier-plate back to its original position ; and if the
bubble is not now exactly in tlie centre, correct as before. Eepeat the
process till accuracy is obtained.
3. Levelling the Instrument, i.e., making its vertical axis truly vertical. —
Clamp the tribrach to axis, and unclamp the horizontal vernier-plate.
Level the horizontal limb's level bv the foot-screws. Turn the horizontal
ADJUST3rENT8 OF THE EVEEEST THEODOLITE. 119
vernier-plate round 90^ and re-level. This will make the vertical axis
approximately vertical. Tlien bring the bubble of the vertical limb's
level to the centre of tube by the two antagonising screws at bottom of
vertical vernier-plate. Tru'u round 180°, and if the vertical limb's level
is disturlied, correct half of the error by the foot-screws and half by the
120 HINTS TO TKAVELLERS.
two antagonistic screws. Turn tlio liorizontal plate 90'', and repeat the
process till accuracy is obtained.
If the bubble of the level attached to the horizontal plate is now dis-
turbed, bring it to centre of tube by the capstan-headed screw, so as to
make it an index of horizontality.
4. Vertical CoIIimation. — Unclamp the vertical limb, and make its level
horizontal by means of the antagonising screws. By means of the vertical
limb's tangent-screw get the horizontal spider-line to cover some well-
defined distant point. Eead off the angle on the vertical verniers.
Reverse the instrument on its bearings, re-level, and re-intersect the
same object. If now the vertical verniers read as at first, the vertical
collimation is correct. If not, the mean of the readings is the true angular
deviation from the horizoatal. By means of the vertical limb's tangent-
screw make the vertical verniers read this true deviation, and intersect
the distant point by means of the antagonising screws.
This will disturb the level of the vertical limb. Eestore its horizontality
by means of the capstan-headed adjusting screws. The verniers should
now read the same angle in both positions of the transit axis. If not,
repeat the process till accuracy is obtained.
5. Horizontal Collimation. — Intersect some well-defined distant point
with the spider-lines. Reverse the instrument on its bearings. If there
is any deviation from the intersection, correct half with the tangent-screw
of the horizontal limb and half with the capstan-headed screws which
move the diaphragm. Reverse the instrument on its bearings, and repeat
similar corrections till accuracy is obtained.
Tacheometer.
A Tacheometer is an instrument for measuring small angles. Of
many different types of tacheometers in use by surveyors the form
adopted by the Indian Government and made by Messrs. Troughton &
Sims is best suited to meet the requirements of the traveller. It consists
of a telescojye A, fitted with a pair of micrometers, B B, which are used for
measuring either vertical or horizontal angles, as they can be tiu-ned
through an angle of 90^, and fixed in that position by the screio C.
The telescope is mounted on standards D D, over a prismatic compass E,
and is furnished with a small circle, F, for taking vertical angles,] which.
THE TACHEOMETER.
121
can be read to minutes. G is the screw by which it is clamped in alti-
tude ; H is the vertical slow motion sn-eio. The instrument is fitted with
a screw (not shown in the plate) for clamping it horizontally, and I is the
horizontal sloiu motion screw. The bearing of any object is read through
the prism N, There are three levelling screivs, K, which fit into a
tribrach L, that screws on a tripod M. The instrument is levelled
by means of the screws K, and a level attached to one of the standards
(not shown in the i^late).
There is a disc of glass visible in the field, divided in such a manner
that each division equals one revolution of the micrometer head, and
122
IIINIS TO TRAVKT.T.ERS.
each micrometer licad is divided into 100 parts. These divisions arc
both vertical and horizontal, to suit the corresponding;- positions in wliich
the micrometers arc used.
Tbe measurement of distances by means of tlic taclieometer is ba.sed on
the solution of a triangle : —
Fig. 1.
c
In Fig. 1, suppose the instnunent to be at A, and a staff of known
length to be represented by BC ; tlien if the angle BAG is measured, and
the length of the staff BC is known, the distance AB can be easily
computed. In order, however, to measure the angle BAG, the value of
the micrometer divisions must be determined in the following manner : —
GarefuUy measure the distance AD from the instrument to a staff of
known length; measure the angle BAG subtended the staff with each
micrometer, carefully noting the number of divisions and decimals of a
division used with each. Divide the length of the rod by the distance AD
between the instrument and the rod, and multiply this by the cosecant of
1" = 206265, and the result will be the value of the angle BAG in seronds
as measured by that micrometer. Now divide BAG in seconds by the
number of micrometer divisions used in taking it, and the result will
be the value of each division of the micrometer in seconds and decimals of
a second. As the value of the divisions will not be exactly the same in
both micrometers their values must be separately determined.
Exmirple: — Number of divisions used (Eight Micrometer), 1157'1 ;
length of rod, 12 feet ; distance between rod and instrument, 9S8'2 feet.
Lo-; 12 = I •079181
Log distance ()'Ai-l = 2 "992642
2-086539
Cosecant of 1" = 206265 Log = 5-ji4425
The whole /_ = 25IT"46 = Log ;-4oos)64
N,.... r r., ,.< Value of each
II57' i> 25I'; 460 (2 17 1 ,. . .
-..rii ^ division.
20326
87550
809.)-;
THE TACHEOMETER.
123
The same process would have to be gone through to find the value of
a division of the Left IMicrometer.
In combination with this instrument a rod of known length is generally
i;sed. Fig. 2 rej^resents such a rod. A A are two boards, one foot
square, painted white, with a black cross on each. These are fastened on
a bamboo, B B, in such a manner that the centres of the crosses shall be a
known distance apart.
When using the rod in a vertical position it will often be found con-
venient to fasten a stick to it, so that it shall extend aboiit two feet beyond
one of the boards. This, when placed on the ground, takes the weight off
the rod and lielps the assistant to keep it steady.
Any theodolite can be used as a tacheometer, by having hairs in the
diai:)hragm fixed at such a distance apart as to read one foot on a staflf
when it is one himdred feet distant from tlie instrument, two feet when
the staif is two hundred feet distant, and so on, and a theodolite fitted
in this manner will always give a proportion of 1 to 100 between the
reading on the r/raduated staff and the distance. As the power of the
telescope is usually small, the figures and marks on the graduated staff
can only be read at a comparatively short distance.
The following precautions must be taken, or no accurate results can be
obtained. The fixed hairs must be adjusted to read in the proportion of
1 to 100, or, what is the same thing, the staff must be marked to read one
foot, when it is 100 feet distant from a certain point. It is the determina-
tion of where this point is that is al)Solutely necessary, and the place from
which to measure the distance is arrived at in the following manner: —
Mark the ground immediately under the centre of the instrument by
dropping the plummet from the centre of the tripod, in the usual manner,
and from this measure a distance, in the direction the telescope points,
equal to the focal length of the object-glass, added to the distance from
124 HINTS TO TRAVELLERS.
the object-glass to the vertical centre of the instrument. Thus, if the
focal length of tlic object-glass was 12 inches, and the distance of the
object-glass from the vertical centre of the instrument was 7 inches, then
the i^osition of tlie point from which to commence the measurement of
the 1(X) feet would be 19 inches from tlie place where the plummet let fall
from the centre of the tripod touched the ground.
To all distances measured in this manner a constant, equal to the focal
length of the object-glass + the distance of the object-glass from the
vertical centre of the instrument, must be added, otherwise there will be
an increasing error in each distance that is measured. (For instructions
for using this instrument in the field, see j). 185.)
Tlie rtane Table.
The plane table is, in substance, a drawing board fixed on a tripod,
so that lines may be drawn on it by a ruler placed so as to point to any
object in sight. Its advantage is, that it enables a survey to be made
without the aid of other instruments, and in less time.
All its other parts are mere additions to render this operation
more convenient, and accurate. Though the principle on which all
plane tables are constructed is the same, they vary considerably in
detail. Those, for instance, used by the United States Coast Survey, and
several of the European Governments, are very elaborate instruments,
fitted with parallel plates and levelling screws, having also a telescope in
the place of the ordinary sights. The plane table then becomes an
instrument of precision, but is much more liable to sustain injury from
accident than in its rougher form, not more so, however, than a theodolite
or sextant. The levelling screws enable the traveller to set up his
instrument much more expeditiously and accurately than he possibly
could without them, and with the telescope he will be able to see distant
objects that would otherwise be too indistinct to be made use of in the
survey.
'The Table. — A is a rectangular board of well-seasoned wood, and can,
within certain limits, be made of any size to STxit the work intended to be
done. To this board the paper to be drawn on may be attached either by
drawing-jMns, clamping-plates, or a hox-wnod frame, E, which is usually
graduated in the same manner as a protractor, and can be used to
125
I'lane Table.
126 HINTS TO TRAVELLERS.
uicaoiirc liorizontal angles, wlieii the fiducial edge of tlic ruler is ])laced
against a pin in a small hole, in a brass plate in the centre of the taVjle,
which is i)rovided for the purpose. A stud, on the under part of the
table, fits into a socket in the tripod, F ; the table can then be revolved
to any liorizontal position, and there fixed by tightening the large nut,G,
on the claraping-screw attached to the stud.
The Trijxxl, F, should be a split one, and for convenience of packing
tlie legs should telescoi)e. This arrangement is also convenient for
setting u]) the instrument on sloping ground. The screws for tightening
the tripod legs should be enlarged at tlie end so as to prevent their falling
out. In many cases it will be convenient to have the plane-table tripod
so made that it can be used for the other instruments.
'J'hc Alidade, B, is a flat ruler, having a fiducial edge, each end of
which carries a sight-vane. On the centre of the ruler is a small circular
level, C, to be used in setting up the table. In mountainous countries a
small telescope fitted on the alidade will be found very convenient, and
where this is not the case, the sight- vanes should be made considerably
longer than would be necessary if the instrument had to be used in a
comparatively level country.
The Compass, D, should have a needle aliout four inches long, contained
in a rectangular metal box, and is sometimes so arranged that when the
needle points to north it will be parallel to the outer straight edge of the box.
A pair of compasses, paper, india-rubber, pencils, a i^en-knife, and some
pins, complete the essentials for i)lane-table work.
It is not considered necessary, in these " Hints," to give any detailed
description of the more elaborate forms of the plane table, but any
person desiring information on the subject can obtain it by applying
to the Instructor at the Society's rooms. {For instructions for using this
instrument in t]ie field, seep. 173.)
Plane Tables used in the Indian ISurvey Department.
By Lieut.-Col. II. H. Godwin- Austen.
A. View of under part of the plane table, showing the brass plate in
the centre with socket-screw, counter-sunk and fixed by screws.
The board should be one inch thick, of well-seasoned wood — deal is
the lightest. Two bars are attached across the grain to prevent warping.
127
1>^
o
F:3
O
o
<1
3
o
11
P-i
r/7
CS
!Z
o '^
o
6
PLANE TABLE SURVEYING.
129
•J8}8UI0JBa
JO piojaay
. I •pioiauy
2 "raoinjaqx
JO -on:
iniod
Snijiog
•aniix
•sssnojf
JO Jaqninii
no jaqninK
S a H
inO HINTF5 TO TRAVELLERS.
fixed by one screw in the middle, witli two at eacli end, working in a long
hole so as to allow of expansion and contraction. The screws should be
bevelled at the shoulder, and a slip of brass should l)e ])laced between the
shoulders of the screw and the wood to pn^vent counter-sinking.
B. View from above, as placed on the tripod-stand, with compass-box
in position. The stand is similar to that used for the photographic
camera, having folding legs and a triangular top of wood with aliole in the
centre for the clamping-screw, C, to pass through. A solid tripod-stand,
as shown in E, is, however, the best, and can be made veiw light and
strong, and it can be used when observing with the theodolite.
D is the sight-rule — as long as the i:)lane table— and packs inside the
waterproof case. The back sight has a narrow slit cut in it ; the fore
sight has a wider slit, with two small holes above and below to receive
the horse-hair or iine wire, which is easily adjusted and retained in
position by little pegs of wood.
Watches.
The keyless lialf-chronometer is the most suitable watch for a traveller
in wild countries. (The half-chronometer watch is a lever watch, with
compensation balance, and a carefully-tempered pendulum .spring.)
The ordinary pocket chronometer is expensive, and not calculated to
stand the rough usage to which most traveller.s' watches are subjected.
The objections to it are : (1) The extreme delicacy of the escapement
and liability to injury from rust or accident. (2) Its great liability
to stoppage from various causes, such as a sudden jerk when riding
or travelling over a rough country ; even if in the act of winding it
the holder should inadvertently give a circular motion to his hand in a
direction opposite to that in which the balance-wheel is moving at
the same instant, it may stop. (When a chronometer is once stopped it
will not start again unless a circular motion be given to it.) (3) The
impossibility of its repair when injured, excejit by high-skilled work-
men, and when very slightly injured, the consequent great disturbance
and irregularity in its rate.
Under favourable circumstances, and in skilled hands, pocket chrono-
meters have done good service, but this is exceptional. The minimum
price of a good pocket chronometer, in a silver case, is -15?.
WATCHES. 131
Half-clironometers are not liable to stop from the before-mentioned
causes, and they are more easily repaired. They may be carried in the
pocket under conditions of rough usage, short of actual violence, and
under ordinary circumstances their performances are frequently but
little inferior to those of a chronometer at rest.
During the last thirty years, great improvements have been made
in the manufacture of the lever escapement, compensation balances, and the
pendulum springs, upon which the ability of a Avatch to keep a steady
rate in a great measure depends. The keyless mechanism has also been
perfected, and it is not necessary to open the case of a keyless watch in
order to wind it; thus the works receive increased security from dust
and damp, the two great enemies of all time-pieces.
The followicg is the description of such a watch as would be best
suited to a traveller. The watch should be a 16-size half-chronometer;
the bezel (or frame which holds the glass) should have neither hinge nor
spring, but should fit very closely over the watch-case, and snap tightly
when pressed home ; great care should be taken to see that the marking
of the minutes on the dial is correct, so that in whatever part of the hour
circle the minute hand shall point to a division, the seconds hand shall
at the same time point to 0. This perfect coincidence for the whole
circle of the dial is by no means common ; its absence is chiefly due to
eccentricity in fixing the dial-plate^ and the error is often so great as to
be a cause of annoyance to the traveller, who will have frequent
diflBculty in deciding as to which minute the seconds belong. The
seconds dial-plate should be sunk, and the glass should be thick flat
crystal. A good watch of this kind cannot be purchased for less
than 20?.
The keyless watch has many advantages over the old form, of
which the following are some: — It cannot be wound the wrong way.
It cannot be o^er-wound, and the case has not to be opened for
winding. When the glass and back are made to screw on, and the
windiDg-buttou is fitted with a screw cap, a watch of this kind has been
placed in water, and proved impervious to damp after several hours',
immersion. Should the winding mechanism get out of order, the watch
can be wound with a common key in the same manner as an ordinary
watch. The cost of a good watch of this description is 37Z.
Care should be taken to wind a watch at about the same hour every
E 2
132 HINTS TO TRAVELLERS.
day, and af5 nearly as possible to subject it to the same daily treatment
■with regard to its position in the pocket, or the place where it is laid
down at night.
In purchasing a watch be sure to go direct to the manufacturers,
and see that it has an "A" certificate from Kew Observatory.
Such watches as those mentioned can only be obtained of the best
makers. Cheaper watches, purporting to have corapenpation balances,
and the best pendulum springs, may be obtained from many shops ;
but it will often be found (when too late to rej^lace them) that they are
not all they profess to be, that they liave never been properly adjusted,
and are, in conseqiience, so affected by change of position and temperature,
as to be useless for scientific purposes.
133
SUKVEYING AND ASTRONOMICAL OBSERVATIONS.
Part 2.
Plane Trigonometry and Preliminary Remarks.
The following formulse are of frequent use in all surveying problems.
In right-angled triangles, B being the right angle, if either A or C is
known, the other is found by subtracting the known angle from 90^. For
the rest we have :
Case.
Given.
Required.
Solution.
' {
Hyp. AC
Angles . .
BaseCB..
Perp. AB
C B = A C X cos C.
A B = A C X sin C.
2&i{
Base C B
Angles . .
Perp. A B
Hyp. AC
A B = C B X tan C.
A C = C B X sec C.
4 & 5 !
Hyp. A C
Perp. A B
Angles . .
Base B C
sin C := A B -i- A C ; cos A = A B -r- A C.
BC=V(AC + AB) X (AC - AB).
' 1
Perp. A B
Base BC
Angles . .
Hyp. AC
tan C =: A B -i- B C ; cot A = A B 4- B C.
A C :=; B C X sec C.
134
HINTS '10 ti{am;i,ij:i;s.
Table II.
Case. ■
Given.
Kequired.
Solution.
■ {
The angles
Side B C
BC=:ABxsinAX cosec C.
and side A B.
Side A C
AC = ABX8inBx cosec C.
r
'J'wo sides
1
AB, BC.and
Angle A
sin A = sin C X B C -^ A B.
itill
angle C
Angle B
B = i8o° - (A + C).
1
opposite to
Side A C
AC = ABXsinBx cosec C.
I
one of them.
B-C A
Tivo sides
tan — — = (AC - AB) X cot y -5- (AC + A B),
A B, A C,
Angles
B + C A
4&S
and the
CandB
and, — 90° — : from which
included
B + C B-C B + C B-C.
Angle A.
B_ ^ + ^ :andC_ ^ ,
SideBC
BC = ABXsinAx cosec C.
From half the sum of the three sides, subtract, separately,
each of the three sides. Multiply these four numbers (the
'
All three
All the
half sum and the three remainders) together, and take twice
sides.
Angles
the square root of the product. This result, divided bv the
product of any two of the sides, gives the sine of the angle
I
between them.
In oblique-angled triangles, if two of tlie angles are known, the third
angle is found by subtracting the sum of the two from 180° ; for the rest
See Table II.
The foregoing equations may be solved by multiplication and division,
■with a table of natural sine.s, cosines, &c. ; but, in order to avoid such a
tedious process, logarithms are usually emi^loyed. In calculating with
logarithms, multii^lication is performed by adding together the log-
arithms of the numbers to be mviltii:)lied : the sum is the logarithm of
the i^roduct : division is performed by subtracting the logarithm of
the divisor from the logarithm of the dividend ; the remainder is the
logarithm of the qiiotient. Tzrice the logarithm of a number is the
logarithm of its square ; and half its logarithm is the logarithm of its
square root.
The following are some of the most useful examples of the practical
application of the rules given in Tables I. and II.
PLANE TRIGONOMETRY.
135
(1.) Wishing to ascertain the height of a point C (Fig. 1), which could
not be approached nearer than B, I observed the angle of altitude
C B D = 46^, and measured the distance from B to A = 200 feet, at which
place I found the angle C A B = 29^
Having found the Z A C B as above, I then computed the length of B C
by Case 1, Table II. Then, as the / C D B = 90", I computed the height
C D by Case 1, Tahle I.
Fig. 1.
From ^ C B D = 46
Take Z. C A B = 29
(2.) To measure the breadth of a river when standing at B (Fig. 2), a
short distance from it, I sent on a man with a staff to a distance which I
judged to be greater than the breadth of the river. I then motioned him
to the right and left until he was in such a position that the reflected image
of the staff was shown exactly over a tree on the opposite bank (as seen
directly), when I had 90^ on the arc of my sextant : having set my sextant
to 45", I walked in a straight line towards the staff until I reached a
position. A, whei'e, on looking through my sextant, I saw the reflected
image of the tree shown exactly over a maik set up at B (as seen directly).
I then measured the distance from A to B, which I found to be 220 feet ;
136
HINTS TO TRAVELLKKS.
from this 1 subtracted 30 feet, the distance of the water, and this gave me
the breadth of the river, I'JO feet.
(3.) In order to measure the breadth of a river I set up a mark, A
(Fig. 3), close to the water ; from tliis jioint I measured a base of 200 yards.
Fig. 2.
parallel to the course of the river, and set up another mark, B. The angles,
subtended by a rock on the o]iposite bank and each end of the base, were
A 75°, B 40^. I then computed the breadth of the river by Case 1
Table 11.
ZB 40
Fig. 3.
180
115
Z C = 6;
PLANE TRIGONOMETRY.
137
(i.) To ascertain the height of an inaccessible point, A (Fig. 4), above
my position C, I measured its angle of elevation with a theodolite, and
Ftc;. 1.
S>—
Fig. 5.
found it to be ■iO : as a river behind me prevented my taking a base in
that direction, I measured one of 200 yards to the left of C and set up a
138 HIN'J'S TO TRAVELLERS.
mark D. The angles subtended by A, at each end of the base, were
found to be, C 94°, D 63°; with these angles and the base CD, I
computed the side BC by Case 1, Table 11. Then, as BC is the base
of the right-angled triangle A B C, I computed the height of the A
by Case 2, Tulle I. Should a sextant be used, the angles A C D and ADC
will be taken, and with these, and the base C D, compute the side
A C by Case 1, Talle II. Then as A C is the hypothenuse of the right-
angled triangle A B C, the height of the point A can be computed by
Case 1, Tahle I.
(5.) The distance between two inaccessible jieaks C and D (Fig. 5)
being required, I measured a base, A B, of 1000 yards, setting up a mark
at each end. I then measured the angles between the two peaks, at both
ends of the base, and found them to be : — at A, 37° and 93" ; at B, 43°
and 111°. In the triangle ABC, by subtracting the sum of angles A and
B, = 136°, from 180°, I found the angle C to be ii" ; by a similar process
I found the angle D in the triangle ABD to be 32^, and in the triangle
B C D, by subtracting 43°, the smaller angle, from 111°, the gi'eater, I
found the angle at B = 68°. Having thus found all the necessary data
in the triangle ABC, I computed the side CB {Case 1, Talle II.), and
in the triangle A B D, I computed the side D B (Ca.se 1, Talle II.). With
the sides C B and B D, of the triangle BCD and the included angle B, I
computed the side D C (the distance between the inaccessible peaks) by
Cases 4 and 5, Table II.
139
Extemporary Measurements.
To set off a Bight Angle from any foint on the ground by nifans of a Bope.
To set off from any point A, a line at right angles to a given direction,
as A E, measure an equal distance on each side of A, in the same
straight line as A E, this equal distance being
about onefourth of the length of the rop?. Let C
and D be these points. Fasten the ends of the
rope at C and D, and having ascertained the
centre of the rope by doubling it, the centre
should be drawn out towards B, until nj B and
C B are tight. Then E A B will be a right
angle ; therefore, as we are thus able to set off
a right angle to any line, the distance of any c
inaccessible object may be obtained by either of "--,
the three following ways : — '~--.
To find the Meridian by a Watch. A . •'
When the sun is visible, the position of the ,.-'''
meridian line can be approximately determined ^''
in the following manner by a watch set to
local time : — Turn the face of the watch to the sun in such a manner that
the hour-hand shall point to the sun, or, in other words, until the hour-
hand itself shall be directly over its shadow. Half-way between the
place of the hour-hand and XII. will be the south point in north
latitude, and the oj^posite point of the dial will be the north point. In
south latitude the reverse of this would be the case, while in the tropics
the i)osition of the north and south i^oints would depend on whether the
sun, when on the meridian, is north or south of the observer. "When
the sun is near the zenith this method would be of little use.
To find the Meridian by the tSun, filliout instruments.
Having levelled a piece of ground of sufficient size, plant a rod in a
truly perpendicular position, testing it with a plumb-line, and at an hour
or two before noon (say 10.30) mark accurately the extremity, C, of the
140
HINTS TO TRAVELLERS.
shadow, B C, thrown by tlie rod when the sun is in the position S ; then
from the base, B, of the rod as a centre, with the radius B C, the length
of the sliadow, describe the circle, D C F, upon the ground. As the sun's
altitude increases, the shadow of the rod will fall within the circum-
ference of the circle, and will gradually grow shorter until noon ; after
which, as the sun's altitude decreases, the shadow of the rod will grow
longer until, at last, when the sun has attained the position S', it will
o
reach the circumference of the circle at the point D. Divide the arc
C D, into two equal jxarts, and from E, a point equi-distant from C and
J), draw a line through the centre B, and that line will coincide, approxi-
mately, with the true meridian.
To Jind the Distance of an inaccessible object with a Measuring Line.
By Fig. 1, p. 141. — From the line A D measure off the perpendiculars
A C, D E, ranging the point C in line with E B, then
AC X AD
^ ^ - D E - A C"
By Fig. 2, p. I4l. — Fix any convenient points H and K. Join H K and
bisect it in J ; make J L = J F, and range I in line with H L and with
J G ; then L I = F G.
EXTEMPORARY MEASURFMENTS.
141
By Fig. 3.— Set off O M at right angles to P, and M N at ri-ht
OW
angles to M P ; then O P = ^^ •
FIG. I
Bouffh Methods of Mrasuring.
Pongh angular measurements may be taken by the span at arm's
length. From the end of the thumb to the end of the middle finger
subtends an angle of 15"^ ; the full span to the end of the little finger
subtends an angle of 18°. This may be easily checked by siDanning round
the horizon ; twenty spans make the circuit. It is at all times well
to know the length of the different joints of the limbs. Suppose the
nail-joint of the forefinger to be 1 inch, the next joint will be IJ inches,
the next 2 inches, and from the knuckle to the wrist 4 inches ; in this
case the finger is bent, so that each joint may be measured separately,
though, when held straight, the distance from the tip of the forefinger to
142 HINTS TO TRAVELLERS.
the wrist would be only 7 inches. The span with thumb and forefinger
wonhl be 8 inches, and with tlio tliumb and any of the other three
9 incites, or equal to the length of the foot ; from the wrist to the elbow
would be 10 inches, and from elbow to forefinger 17 inches, and from
collar-hone to forefinger 2 feet 8 inches ; lieight to the middle of the
kneecap 18 inches. From the elbow to the forefinger is usually called a
cubit, but it is seldom strictly so, an Englisli cubit being generally stated
as 18 inches. In b'ke manner the full stretch of the extended arms is
called a fathom ; but it is generally somewhat less.
Tlie pace is commonly supposed to be 2|- feet, but this is a most
uncertain mode of measurement. Very few men, ivithont practice, can
take correctly a hundred consecutive steps or paces of the same length.
Practice will determine the amount of ground covered in a certain
number of paces, if tried over known distances ; it of course varies, but
from experiment the mean has been found nearly as follows :
Pacing, at 30 inches per pace, of 108 in a minute, equals 270 feet, or
3 "008 statute, or 266 geographical miles per hour.
Pacing quickly, at 30 inches per pace, of 120 in a minute, equals
300 feet, or 3'41 statute, or 2'96 geographical miles per hour.
Pacing slowly, at 36 inches, may average 60 per minute, equals 180
feet, or 2"0i statute, or 1"78 geograj^hical miles per hour.
The height of a tree, or other accessible object, may be found ap-
proximately by walking away from it, until, with your back to the tree,
by bowing your head down as far as you can, and looking between your
legs, the tree top is just seen ; then pace the distance to the tree, and this
will be its height. This method is in common use in the logging camps
of North-West America, and from constant practice the backwoodsman
will tell to a few feet how far the toi? of a tree, he is going to cut down,
will reach. The legs must be kept straight, and only sufficient space left
just to see between them.
Distance hy Sound.
Sound travels at tlie rate of about 1090 feet in one second in calm
weather and temperature 32^ Fahr., and increases at the rate of 1 " 15 foot
for each degree of temperature above 32° ; a moderate breeze accelerates or
retards sound by about 20 feet in a second. When a gun is used
KOUGH TKIANGULATION. 143
to measure distance it should always be pointed at an angle of aliout
■45^ to the horizon. This method will be found most useful in making
rough surveys of winding rivers or lakes, where it is imiiossihle to land
on account of the dense undergrowth or the swampy nature of the banks.
Great accuracy may ))e obtained if a gun is fired at each end. Abase
for a small triaugulation can be measured by this means.
Table fok Eough Triangulation without the usual Instruments,
AND WITHOUT CALCULATION. Bl/ FrANCIS GaLTON, F.R.S.
A traveller may ascertain the breadth of a river, or that of a valley, or
the distance of any object on either side of his line of march, by taking
about 60 additional paces and by making a single reference to the Table
on page 144.
Suppose he is travelling from A to Z (Fig. I., p. 144), and wishes to
learn the distance from A to C ; and it may be, also the angle A. Let
him proceed as follows (referring now to Fig. II.).
1. Leave a mark at A. 2. Walk ten paces towards Z, and make
a mark, calling the place m. 3. Walk back to A. 4. Walk ten paces
towards C. 5. Walk to m, counting the paces to the nearest half-pace.
(This gives the measurement of the line a (Fig. I.), which is the chord of
the angle A, to radius 10.) 6. Walk 80 paces towards Z; make a mark,
calling the place n. 7. Walk ten paces towards Z, calling the place B ;
this completes 100 paces from A. 8. Walk ten paces towards C. 9.
Walk to II, counting the paces to the nearest half-pace. (This gives the
line h, which is the chord of the angle B, to radius 10.)
Now enter the Table with a at the side and h at the top, and read off
the distance A C, and the angle A if also required.
If the Table be entered with I at the side and a at the top, it gives B C
(and B).
Of course, the units need not be paces: feet, furlongs, miles, hours,
journey, or anything else will do as well ; and the units of A B need
not be the same as those of a and h. Also any multii)le or divisor of
100 for A B may be used, if the tabular number be similarly multiplied.
144
KOUGH TRIANGULATION.
00 N
IV. O
■■ M
O ir,
ONO
o
■+I/N
t 1
,'
- 2 o
fa -z
' X2
o" o"
o o
O "vv
o
O
22^
o
CNf-
l/§
CO '■'N
CNO
-o
IfN rf
M
•r-O
ON ON
OvO^
ON ON
o o
NO 0^
o o
^co
NO o
E
CNO
00 03
O M
o-a>
00 00
C7- CN
00 ON
»i- oc
ONO
5<CN
O 'A
o o
On ON
o -
83"
GO "^ O 00
O '- c4 n
CO O
'••N UN
M M
o
=3-^
o o
U- ><V nC oo
00 00 t» oo
CO CO CO 00
oo 0^
-^o
oo O
CO cr»
§2 2r
^'N I^ N« O
o>o> o o
UN U\
•4 M
oo
-r
09
o
^r^■^
^^
pp
00 00
r^oo
ON-
r^oo
i#nnO
So?
O ON ^oo
30 00 OnOn
O ~1 u^ On
00 OO 00 CO
~N ON
o O
ON ON
OD On
2 =
Ho
O
R5^
1-c O
oo r-
o o
O ►-
r-co
n-nO
Nt\0
Ng^^
r^oo
00 o>
r--oo
UN M
CO ON
a "N
ON so
Ono
o
o
nOO
OnO
C>co
WN UN
NOO
ITN V\
oo
1^00
u^ u^
00 ON
UN UN
O M
OO
O ~>
n3^
P5
nS'?^
oo ON
C-'OO
2^
Sn^
1
10
25,
IfN ITN
O On
•». UN
oooo
UNO
I- ON
us WN
oo
UN 1^
UN UN
o I^
oo
o-oo
Angle.
i8 58
31 56
5^ B^
0-*
5:1
=11
OcSo
S2'
o •*>
10
o -t»
O -("
<0
O H"
A
o -*•
e
o •♦•
H
ri
o ■♦•
m
H
10
0-*
ROUGH TRIANGULATION.
145
Examples.
a
(in paces).
6
(in paces).
7
A B.
A C.
Angle A.
B C.
Angle B.
5
5
JOi
I of
loo paces
50 miles
100 paces
1000 paces
67 paces
jji miles
68 paces
680 paces
;
28 58
28 58
6} 22
t} 22
5 J paces
26i miles
92 paces
920 paces
1
31 56
41
41
Particular care must be taken to walk iu a straight line from A to B.
It will surprise most people, on looking back at their track, to see how
curved it has been, and how far B n is from pointing truly towards A.
It is important to sight some distant object in a line with Z when walking
towards it.
The triangle ABC must be so contrived that none of its angles are less
than 30°, or the chords of the angles at A and B will not be found in the
Table. These cases cease to give reliable results when the measurejnents
are rudely made, and have therefore been omitted.
Should a traveller have no Tables by him, he can always protract his
measurements to a scale on a sheet of paper, or even on the ground, and
so solve his problem. If real accuracy be aimed at, it is clear that it may
be obtained by careful measurements of the base and chords, combined
with a rigorous calculation, as was first suggested by Sir George Everest,
formerly Surveyor-General of India. (See ' Journ. E. Geog. Soc.,' 1860,
page 122.)
Ascertaining Heights hy Angles of Elevation.
When using an angle of elevation to ascertain the difference of height
of a mountain top and the position of the observer, it must be recollected
that, if at any distance, a large part of the mountain is below the hori-
zontal line, and therefore the perpendicular of a right-angled triangle will
only represent a portion of the height. To allow for this, the following
correction, which includes mean refraction and curvature, must- be added
to the true angle of elevation.
„ , . . 1 - distance in geog. miles x 100
Correction, in seconds of arc, = j
146 HINTS JO riJAVELLERS.
Ex imple. — Observed ■with a tlieodolite the elevation of Kilimanjaro to be
6° 03' from a iiosition afterwards found to be 25 miles distant.
95 y 100
Correction = ^ = 625" = 10' 25"
Corrected elevation = 6^ 03' + 10' 25" = 6" 18' 25"
Constant log. (of 6046 ft.) 3-7815
Log. tangent 6° 13' 25" 9-0376
Log. 25 1-3979
Height above observer's position = 16,480 feet . log = 4 2170
Flashing Signals.
A flash from a small mirror is of the greatest use in surveying. Mirrors
mounted so as to turn in any direction are sold by opticians under the
name of heliostats, and a flash from one of two inches square may be seen
fifty miles. It requires, however, an intelligent person to direct the
mirror, and cannot therefore be worked by a native or untrained
European. Mirrors fitted for this purpose are made of accurately jjarallel
plate glass and a small hole is made in the amalgam and the plate pro-
tecting the back of the glass.
Planting the stand of the mirror fairly, the hole in the centre is looked
through, and a piece of paper working on a stick, which must be stuck in
the ground about ten paces distant, is brought into exact line with the
object to which it is desired to flash and when the observer is in
readiness to take the angle to the flash. The mirror is thentiirned about
until the flash from the sun illuminates the paper, when the observer at
the distant point will also see it. The flash must be kept carefully on the
paper until an answering flash shows that it has been seen and observed.
Two surveyors working together in this way can obtain most accurate
observations without any time being expended in erecting marks. In a
persistently cloudy climate, the method is, of course, of little use.
Measurement of the Number of Cubic Feet of "Water conveyed
by a elver in each second.
The data required are — the area of the river-section and the average
velocity of the whole of the current. All that a traveller is Likely to
obtain, without special equipment, is the area of the rivcr-seclion and the
VOLUME OF RIVERS.
147
average velocity of the surface of the current, which is greater than that
of its entire body, owing to frictional retardation at the bottom.
To make the necessary measurements, choose a place where the river
runs steadily in a straight and deep channel, and where a boat can be
had. Prepare a few floats of dry bushes with paper flags, and be assured
they will act. Post an assistant on the river-bank, at a measured dis-
tance, of about half the estimated width of the river, down stream, in face
of a well-marked object. Row across stream in a straight line, keeping
two objects on a line in order to maintain your course. Sound at intervals
from shore to shore, fixing your position on each occasion, by a sextant-
angle between your starting-place and your assistant s station, and throw
the floats overboard, signalling to your assistant when you do so, that he
may note the interval that elapses before they severally arrive opposite to
him. Take an angle from the opposite shore, to give the breadth of the
river.
To make the calculation approximately, protract the section of the river
on a paper ruled to scale in square feet, and count the number of squares
in the area of the section. Multiply this by the number of feet between
you and the assistant, and divide by the number of seconds that the floats
occupied, on an average, in reaching him.
Important rivers should always be measured above and below their
confluei.ce; for it settles the question of their relative sizes, and throws
great light on the rainfall over their respective basins. The sectional
area at the time of highest water, as shown by marks on the banks, and
the slope of the bed, ought also to be ascertained.
Example.
Distance from Shoke j
Whence the boat started, mea-i
sured in feet /
Depth at those distances mea- 1
sured in feet /
Time required for float to drift)
opposite to assistant, mea-V
sured in seconds )
Start-
ing
place.
o
90
160
240
o
2
i\
4
-
48
50
40
iio 420 j 500
ij ! 29 ! 27
600 j
i
10 I
Oppo-
site I
Shore.
I 780
Ik
I Ave-
I I rage.
50 j — i8-4
Distance of assistant, in feet, ijo.
L 2
148 HINTS TO TRAVELLERS.
By ijrotracting the data on the first two lines, on ruled paper as
described above, it will be found that the area of the section is 3260 feet,
or thereabouts; this, multiplied into 150, gives 489,000 cubic feet of
water as the contents of the river at any given moment between the line
of soundings and the assistant. As this amount passes by in 38'4: seconds,
the number of cubic feet per second is the former number divided by the
latter, which gives 12,734.
It must be distinctly understood that this number is only roughly
approximate, and that it is excessive. However, with the above data,
an engineer would be able to make a somewhat better calculation. In
the meanwhile, the traveller might consider the flow of the river in
question to be between 10,000 and 18,000 feet per second.
Map Pkojections.
Mercator's Projection.
On a sheet of cartridge paper, 13 inches by 20, it is proposed to con-
struct a map on Mercator's projection, on a scale of 10 miles to an inch
equatorial — i.e, 6 inches to the degree of longitude.
T • •+ f +1 AT ^ Lat. 31° to 33^ N.
LimitsoftheMap|^^^^3^,^^3g,^_
Draw a base line, find its centre, and erect a perpendicular to the top of
the paper; the extremes of longitude 34° and 36^ added together and
divided by 2, give 35°, the central meridian, and which is represented by
the perpendicular ; on each side of it lay off 6 inches, and erect perpen-
diculars for the meridians 34 and 36; divide the base line into 10-mile
divisions, and the part from 35° 50' to 36° 00' into miles for the latitude
scale.
From Table A, take the following quantities : —
Lat. 31° to 32° = 1° 10' 4 = the distance between parallels 31° and '62°
,. 32° to 33° = 1° ir-1 „ „ „ 32° .. 33°
2° 21' -5 „ „ „ 31° „ 33°
Having thus obtained the distances between the required parallels,
divide the map into squares of 10 miles each way, and the map is ready
for the projection of the route.
MAP PROJECTIONS.
149
H^
NO
1*1
M
VO
CO
00
H
M
T1 ,4
^
8
**^
CO
so
o
-1-
t^
^
t4
la
o A
O
o
UN
o
■f
o
"
"
M
^
UN
.S "s
e 3
w>
!?•
t~
r-
CO
-«•
CO
■<^
*^
o (0
o
8
M
o
M
o
M
«
*r\
VO
is
If
^
v£>
vO
H
«ri
w
o
a ^
•^
8
^
t^
Tf
(^
o
O
J^
1 a
o t*
'^
•^
M
o
*^
M
M
"
M
M
■^
•i-
o
^ a
ri,-"
•^
O
ON
On
8
^0
*^
yf
w
■^
■^
5 »
o
•^
^
^
M
"
M
M
~N
w
"S &)
^ -S
■*•
oe
M
r^
o 10
o
8
o
IH
■ij-
■i-
M
o
1^
C3 O
M
t~
Wl
f-
00
>»>
»^
M
*■
8
r4
(^
o
M
1^
o «
o
M
M
M
' M
"
CO
O
3 —
t3
en 2
a OS
M
u^
<T>
M
■<r
vf>
ON
NO
o m
o
8
o
M
1-
O
M
M
g^
M
On
M
^
<^
-*
M
■*
OO
M
Nl-
■s o
*■
O
M
-1-
o
o
a^
o (4
«H
*^
^
o
M
M
«
HI
M
M
M
^
o
^2
11
M
VO
•^
00
CO
8
M
t-
ON
a<
■<)•
^
ON
- ^
° ri
"N
"^
M
"
■^
■^
M
'^
«
NO
_» "1
o
o
vO
•*
f^
IN^
UN
^s
o
o
r-.
^
,.4
® .9
e
M
-
H
t-t
-
— a
.9 f
o
e
O
O
e
o
e
o
o
tq $
H
N
«
*
10
«
t*
00
•S
'^ 5 -a
^ o ^
■3 5 "3
o" ^ o"
f « f rr
O t3 o O -I
O C jH H «
; ^ .^ ^ •-( M
I'l'i II II
3 -w t4 n ~N
■3 °-3
150
HINTS TO TRAVELLERS.
o 0)
•«oo ■^eo ««o -H-O r~
O O >- c< •>^ O r- M .
o CO
o o M M ^rcosooo^o
" ^
£-><;<>< Nvo^o oif\ce
W
10
CO '^'^oowu%Mr^
«
OOOt<'-ir-MVD««i
o n
Or*ooO^\ONOOrlO
o e)
000»H«s^\Oi-ic?«
o H
Mr-iH»000OOu^
coo *-io li^O^c* i-i M
5oo>■|^u^oO'^
O
oOoeoeoeeo
HNm*io»t»(0
^ .c «J
m ja _ o
o £
- s
X 2,
M CO
X
S 3 Q .
5=E. 6
H £ £ i i:
fc. -S H - -
MAP PUOJECTLON.S
151
Conical Projection,
The conical projection, or cleYelopment, is
carried out thus : draw a straight line, A B, to
represent the central meridian of the intended
map, and after having decided on the scale on
which it is to be laid down, set off along this
line A B, from the point A, scales of equal parts,
for each 1^ or 5°, as the size of the scale may
admit. Also measure off from A towards B the
distance A C = 57-29578 x length of 1° in inches
X cot. lat. of A. Then with C as a centre, and
C A as a radius, describe an arc of a circle
through the point A, representing the parallel
of middle latitude, and divide it also into equal
parts indicating 1° or 5° of longitude, each l°of
longitilde being equal to 1° of lat. x cos. lat. of
A ; and from C draw the radiating lines, repre-
senting the meridian through the points laid
off on A E, and also concentric circles through
the points marked off on A B for each 1° or 5°
for the parallels of latitude.
For the Eectangular Tangential Projection,
see a pamphlet with Tables published by the
Ordnance Survey Department, "On the con-
struction and use of marginal sheet lines, for
the uniform projection of maps in any part_, of
the world."
J.52 HINTS TO TRAVELLERS.
SURVEYING AND ASTRONOMICAL OBSERVATIONS.
Paet 3.
SURVEYING.
Mapping a Country.
The surveys that are mostly possible for travellers are route surveys,
i.e., laying clown as much of a country as comes within the ken of a
traveller on his line of march. Such surveys, if of any extent, must be
assisted by astronomical observations to prevent the accumulation of
errors. {See p. 188.)
Route surveying can be accomplished in several ways, but in any case is
not an easy task for one who has no experience of ordinary surveying, as, to
be successful, it requires a knowledge of how to make the most of oppor-
tunities, of which method is applicable, and generally a mastery of the
various dodges by which alone an irregular survey can be made to give
a result fairly approximating to the truth.
The principle underlying all surveying is to start from a base line of
known length, and by means of angles or bearings to obtain rays to
conspicuous objects from both ends, by the intersection of which their
position can be fixed. Details are sketched in between.
The base line may be long or short, may be measured, either accu-
rately, by means of a tape, cord, chain, etc., or by astronomical observa-
tions ; or, roughly, by estimation of the distance walked in a straight line.
Tacheometer surveying is a method in which an extremely short base
is used, the angle subtended by it at a point at right angles to the centre
of the base being measui-ed from the point to be fixed ; in this case Hot
at a great distance from the base.
To aid the traveller, descriptions will be given of ; —
(1.) Route surveying with Prismatic Compass, p. 153.
(2.) Surveys with Sextant and Prismatic Compass, p. 162.
(3.) Surveying with a Plane Table, p. 173.
(4.) Surveying with a Tacheometer, p. 185.
COMPASS SURVEY. 153
The scale of the intended survey is an important point.
This will yary much with circumstances, but the limits of scale for
ordinary route surveys may be roughly stated as from half an inch to
one-tenth of an inch to the geographical mile.
The geographical mile should be chosen, as it facilitates the intro-
duction of astronomical positions from time to time.
Whfle parts which seem to require more detail may be mapped on a
larger scale, and reduced into the general map, it will ordinarily be
found that a scale of a quarter of an inch will be the most convenient.
It is above all things necessary that a traveller should state distinctly
how his map has been made, the bases used, the instruments employed,
and generally all information that will enable the map compiler to judge
of the value of the work. The compiler has in most cases to fit the new
work into old, and without some information which enables him to
appraise the value of both, he is at a loss what to do when dis-
crepancies, which are unavoidable in such work, occur.
Some portions of a route map are certain to be less accurate than
others, and the traveller should append remarks on this head, because
the object of all travellers surveying is to add to correct mapping, and
not to displace previous work by the new, without regard to the accuracy
which may attach to it.
Any work incorporated from a previous map should be distinguished
in some way to avoid confusion, and if such work has been altered to fit
the explorer's positions, it should be stated.
Route Survey with Prismatic Compass, Boiling-point Tliermometer,
and Aneroid.
For the purpose of illustration, siippose the following to be an extract
from a traveller's journal : —
June 1st. — Camp at the foot of hill A, and 2| miles distant from its
summit, the magnetic bearing of which was 146°.
To measure the height of the hill A, above the camp, I read the
aneroid and thermometer, first at camp and then on its summit, with
the following results : — At camp, aneroid, 25*67 inches ; temperature in
154 HINTS TO TRAVELLERS.
the sluade, 70" Fahr. ; at the summit of the hill, aneroid, 24-25 inches ;
temperature iu the shade, 65° Fahr. At the summit of hill A, I took
the following bearings, and a rough sketch of the country to the north,
marking all prominent objects with a letter corresponding to the letter
given to the bearing.
Bearings taken at A: G 351° 30'; F 340=; E 326°; D 308°; C 300°;
B 283°. All bearings magnetic.
June '2nd, 8 A.M. — Aneroid, 257 inches; temperature in shade 78°
Fahr. Struck camj), and travelled in a direct line towards hill marked
E in the sketch, and at a distance, which I estimated to be fifteen geo-
graphical miles, we arrived at the right bank of a river, where we camped
for the night. The country over which we have passed this day is
destitute of trees, sandy, with patches of grass here and there, and
gradually sIoidgs downwards from our last camp to our present position.
6 P.M. : aneroid, 25'98 inches ; temperature in the shade, 68" Fahr. ; took
the following bearings : —
Bearings taken at camp, 2, by river : D 270° ; B 204°; A 146°; G 100°;
F 8°. All bearings magnetic.
June 3rr/, 8 a.m. — Aneroid, 26"05 inches; temperature in shade, 78°
Fahr. Struck camp, and forded the river, which, after winding in an
easterly direction from the hill, marked D in the sketch, to a point one
and a half miles N.E. by E. of the ford, takes a bend to the S.E., passing
to the west of the hill marked G on the sketch. At a distance of one
mile below the ford, a large stream from the north flows into the river.
Continued to travel iu the direction of E, and at noon found that we had
arrived at a point whore C and F and our position were in one line of
bearing— 81^ and 261° magnetic. During our halt, boiled a thermometer
and read the aneroid, with the following results : water boiled at 201'3° ;
aneroid, 25-62 inches; temperature in the shade, 71^ Fahr. 3 p.m.
Resumed our journey, and at 6'30 p.m. reached the summit of the hill E,
where we camped ; estimated distance travelled, nineteen geographical
miles. Aneroid, 24"60 inches; water boiled at 202'3°; temperature in
the shade, 64° Fahr. Since leaving camp this morning, the country
through which we passed was covered with vegetation, and we had the
large stream to the right of us throughout the day. From this hill, E,
we can see that the river we forded this morning takes its rise in the
range of hills to the west of our present position, and flows with a wind-
COMPASS SURVEY. 155
ing course through the valley at the foot of the hill D, and so past our
last camping-ground.
Bearings taken at E : C 236° 30', and southern end of summit of same
range, H 215° ; D 174° ; B 168° ; A 146° ; G 133° ; F 118° 80'. All bearings
magnetic.
June ith, 8 A.M. — Aneroid, 24*65 inches ; temperature in shade, 66°
Falir. Set out in a N.W. direction, and having no prominent object in
view on the line of march, I noticed the direction in which my shadow
was cast, and by this means, allo-ning for the sun's apparent motion, I
avoided making any general deviation from the direction in which I
wished to travel. Arriving at a small lake, we camped, having come an
estimated distance of twelve geographical miles. Fixed the position of
the lake by bearings of C and E.* Aneroid, 25'50 inches ; temperature
in shade, 70° Fahr.
Bearings taken at camp, near lake : C 195° 30' ; H 185° 34' ; E 113° 30',
All bearings magnetic.
To Plot the Bearings : — This can be done either on the true or magnetic
meridian. The bearings being magnetic, it saves much trouble, and also
chances of errors, to plot them from the magnetic meridian.
Through the station A draw with a pencil a line to rejjresent the
magnetic meridian in a direction convenient for the route. Place the
protractor with its centre mark on A, and the 360° on tlie magnetic line,
and set off the bearings observed.
The second camjD being in the direction of hill E, measure 15 miles, on
the scale adopted, on the Line drawn toward E, which will give the position
of Camp 2.
From this position lay off the bearings obtained, in a similar manner,
baviug first drawn a magnetic meridian through it parallel to the first.
The intersection of two lines of bearings of any one point, as taken from
two different stations, wall fix the position of that point with reference to
the stations. If the true meridian is used, the procedure is the same, but
each bearing must be corrected for the variation before laying-off, which
can be api:)roximately ascertained from the variation maj) (p. 158).
* Take 180° from C for its opposite bearing. Add 180° to E for its opposite
bearing.
156 HINTS TO TRAVELLERS.
The line drawn through A will then represent the true meridian. In
both cases it should be stated on the map whether the meridian is true or
magnetic.
Each station where bearings are taken must be plotted in a similar
manner to Camp 2, that is, by bearing from the last station, and by
estimated distance. Having by means of the first two stations fixed hills
off the line of march, bearings of these will assist to obtain the position
of the third, and so on. When no object can be seen to march for, the
direction must be obtained by compass bearing of the lino of march
obtained from time to time.
The aneroid readings, and the boiling-point, furnish us with the means
of ascertaining the difference in height of two stations, which may be
computed by the tables (see pp. 313 to 320), or, where the height is not
considerable, by a simple arithmetical process as follows : —
Take the sum and difference of the aneroid readings, at the upper and
lower station, get the mean of the temperature in the shade at the two
stations. Then, sum of readings : difference of readings : : 55,000 : the
difference in height. Increase the result thus found by -^l^ of itself for
every degree that the mean temperature in the shade at the two stations
exceeds 55"^; subtract the like amount if it is below 55"^. The aneroid
readings, in the example, computed by the tables and this formula, will
show a fairly close agreement.
Approximate g Tables
Method. '^y laoies.
Feet. Feet.
A, above Camp 1 i6o8"5 .. .. 1603*8
1st Camp above 2nd Camp 310 .... 308 '8
Foot of Range above 2nd Camp .. .. 477' 2 .. .. 475 "9
Height of Range E ii48'2 .. .. ii45'o
„ by Boiling point .. .... ii55'3
E above Lake 959*2 .. .. 956-5
For plotting the work in the field, a scale of one inch to the geographical
mile will exhibit all the main features of a country traversed in a day's
journey. Special plans miist be drawn on a scale suited to the area they
are intended to represent ; but whatever scale is chosen for the field work,
it should be large enough to admit of considerable reduction in the fair
plan, as by this process all errors are diminished. The projection of maps
COMPASS SURVEY. 157
is purposely omitted here, as it is dealt with separately (see p. 148) ; it will,
however, be of great assistance to the traveller if he provides himself with
a blank map, on the scale of ten geographical miles to an inch, of suflQcient
range in latitude and longitude to include the country he intends to
explore. He should also procure some paper ruled with dark lines into
inch squares, and then again subdivided into iive smaller squares ; this
will be useful to him for plotting his work in the field, and should be
made up in the form of an ordinary sketching-block. Should the lati-
tude and longitude of the point of departure be known, the latitude and
longitude of any place on his route can be approximately determined
by working the traverse as directed in articles 286 and 324 of Eaper,
or pages 115-120 of Norie. It must not, however, be supposed that
an accurate survey of a large tract of country can be made with tlie
aneroid, prismatic compass, and boiling-point thermometer; the most
that a traveller could expect to do with the aid of these instruments
would be to make a rough sketch of the country through which he
passed. But instances are not wanting where travellers, by a judicious
use of these simple instruments, have added very considerably to our
geographical kcowledge. The map of Schweinfurth's journey to the
Welle is an example of what can be done with the material furnished by
such observations.
The weak points in this method of surveying are, the errors caused by
false estimates of the distance travelled, and those arising from the effects
of local attraction on the compass. Knowing these sources of error,
every care should be taken to guard against them. With regard to dis-
tance, the only safe way of estimating it is, by carefully noting the time
occupied in passing from one place to another. In almost all countries
bodies of men have a nearly uniform rate of progression, and by taking
an early opportunity of noting this rate, the distance traversed in
a known period of time can be fairly estimated. Schweinfurth, before
setting out on his great journey to the Welle, carefully noted the time
which it took him to pass over a known distance at a regular pace, to
which he had trained himself; and truly wonderful results have been
attained by native surveyors in India by following the same plan. The
only precautions that can be taken against the effects of local attraction
on the compass are, to be careful when taking a bearing to put all arms,
such as rifles, at some distance from the compass; as a general rule.
158 HINTS TO TRAVELLERS.
where possible, to avoid all rocks; and to take bearings both forward
and backward on the route travelled, taking their mean as the magnetic
direction of the route. In a country thickly covered with forest it is
most difficult to distinguish landmarks. The traveller may, however,
sometimes leave a mark recognisable at some miles distance by giving
a little consideration to it, and knowing the direction in which he is
proceeding.
Enter every observation and change made in the general direction
travelled, with the date and time, in the journal ; as without attention
to this, much valuable information may be lost. When preparing MS.
to be sent home for publication, write each of the native names, at least
once, in printing character. Numerous errors and great loss of time
frequently result from the attempt to decipher proper names written by
travellers in their ordinary handwriting only.
The bearings given in the journal have been laid down on the annexed
map, corrected for 20° easterly variation, and will serve to illustrate the
manner in which this portion of the work is done.
Scale Ilnch-jO Geo Miles
12 3 + 5
Published, ~by the Boval Geocp'ophuxJ/ Socintv ui "Sints to Tra^'eUers". JS53 .
-1893.
trc.
15° 10" EVariatian..
( 159 )
Hints on Use of Sextant in Subveying.
To measure the Angular Distance hetween two Objects.
When tlie horizontal angles between terrestrial objects have to be taken
with the sextant, the index is set to zero (0°), anil the instrument must
be held in the right hand in such a manner that its plane is i^arallel to
an imaginary line joining the two objects ; put back all the dark shades,
and, looking through the telescope collar and the horizon glass at the
right hand object, unclamp the index and move it slowly forward until
the reiiected image in the mirror of the horizon glass coincides with the
other object seen directly; clamp the index and make the coincidence
perfect with the tangent screw, then read the angle. Make it a rule to
commence taking the angles from the object farthest to the right, then
from the next farthest, and so on, always working from right to left.
By so doing mistakes will often be prevented in plotting the work, and
you will be able to recognise the objects from which angles have been
measured in your rough sketch. Avoid very large or very small angles,
as they may cause considerable errors in the i^ositions assigned. Should
it be required to measure the horizontal angle between two objects, one
of which is at a considerable elevation above the other, as a tree on a jDlain
and a mark on the toj:) of a hill, it will be necessary to select some object
immediately below the mark on the hill, and as nearly as possible on the
same level as the tree, and measure the angle subtended by them. If uo
object in a suitable position can be seen, select some point about 90^ or
100^ from one of the objects, and observe the angles between each object
and that point; the difference between these two angles will be the
horizontal angle, nearly. Should tlie angle be too large to be taken in one
measurement, the object to the right must be brought by reflection to
some well-defined mark, and the reading taken ; the angle must then be
measured between the mark and the other object; the sum of these
readings, after the index error for each measurement has been applied,
will be the angle required. Though the angles measured with the
sextant are seldom, strictly speaking, the true horizontal angles, yet the
errors arising from their obliquity are extremely small, if they have
been well chosen, and indeed would be scarcely discernible, in work
160
HINTS TO TRAVELLERS.
plotted with the ordinary protractor, which is only divided to 30'. A
reference to the following diagrams will, it is hoped, make the previous
remarks on this subject more clearly understood.
In Fig. 1 let A B be two objects, the place of the ob.server; then the
objects would appear in tlie horizon glass as shown in Fig. 2, when the
angle was taken ; A being seen in the mirror, B by direct vision through
the unsilvered part. If the angle A B had to be taken by two measure-
ments, A C would have to be taken first, and then the angle COB; the
sum of these two angles, which is the angle A B, is the horizontal angle
between A and B', very nearly, because B is directly beneath B', and is
more nearly in the same horizontal plane as A. When a box sextant is
used the reflected image is seen above the object by direct vision. In
Fig. 8, if the horizontal angle between A and B had to be measured, select
a point such as C, more than 90° from A, and at 0, the place of the
observer, take the angles A C and B C ; the difference of these two
angles wall be more nearly the horizontal angle between A B at 0, thiin
the angle A B.
Table for ascertaining Heights and Distances by the Sextant.
Mui.
Angle.
Angle.
Div.
o /
/
I
45 oo
45 00
I
2
6i 26
26 u
18 26
2
3
71 M
i
4
75 58
24 2
4
5
•78 41
II 19
5
6
80 i2
9 28
6
8
82 52
•J 08
8
lO
84 17
5 4?
10
The sextant being set to any angle contained in the Table, any height
or distance of accessible or inaccessible objects may be obtained in a very
simple and expeditious manner. Make a mark on the object, if accessible,
to the height of the eye ; set the index to any angle from the Table, and
advance or go backwards from the object, until, by reflection, the top of
the object is brought by the mirrors to coincide with the mark fii-st made.
If the angle be greater than 45°, multiply the distance to the object by
the mimber in the next column to the angle in the Table ; if the angle be
162 HINTS TO TRAVELLERS.
less than 45'', divide, and tlie result will be the height of the object from
the mark ; to which add the height of the eye.
If the object is inaccessible, set the index to the greatest angle in the
Table that the least distance from the object will admit of; move back-
wards and forwards until the top of the object is reflected level with the
eye ; at this place set up a staff equal to the height of the eye. Then set
the index to any of the lesser angles; go back in a line with the
object, until the top is made to apjiear on the level with the top of
the staff; fix here another mark ; measure the distance between the
two marks set up ; divide this by the difference of the numbers corre-
sponding to the angles made use of, and the quotient will be the height of
the object from the top of the staff; to which add the height of the eye.
If the index is set at 45°, the distance is equal to the height, minixs the
height of the eye.
At a given point to mark off a line perpendicular to any given direction. —
If this direction is not sufficiently distinguished by some natural object,
such as a tree, mark it by a flag set up as far off as convenient ; then,
standing at the given point, with the sextant set to 90°, make a man,
bearing a flag, stand in a line estimated as the perpendicular. Motion him
right or left until his flag can be seen, by reflection, to coincide with the
other. There let him plant his flag, so marking the direction of the
l^erpendicular.
Of course any other direction can be marked in the same way, setting
off the required angle on the sextant, instead of the 90°.
Surveys with Sextant and Pkismatic Compass.*
By Col. Sir C. W. Wilson, r.e., k.c.b.
A traveller who intends to devote a portion of his time to the survey
of the country he is about to visit, should consider before leaving home
what he is going to do, and how he will do it. The character of the
proposed survey, the projection to which it is to be referred, the scale or
scales to be adopted, the instruments to be used, should be carefully thought
* It will be understood, that if a small theodolite can be cai'ried, the work of
Burveying will be greatly facilitated.
SEXTANT AND PKISMATIC COMPASS SURVEY. 163
over before commencing work, and there should be no hesitation when
once upon the ground. A decision on these points depends on various
considerations— such as the time and means at the disposal of the traveller,
the object in view, the nature and geographical position of the country,
&c. ; and the following notes are confined to a few hints which may be
useful in the field.
Projection. — When the extent of country to be laid down is small, it
may be treated as a plane-surface ; but when it is considerable, allowance
must be made for curvature, and some projection of the sphere, or a
portion of the sphere, adopted. The projection should be selected with
reference to the latitude and local peculiarities of the country to be
surveyed ; the sheet should be prepared before leaving home by a com-
petent draughtsman, and two or more copies of each taken, packed in a
round tin plan-case. It may happen, however, that a projection has to be
made in the field, and a few notes are given on the construction of
Mercator's, the Conical, and the Eectangular Tangential Projections
(see p. 148). In Mercator's Projection, the true proportions are preserved
between the meridians and the parallels, and the figures of the objects
delineated are in every part correct ; but the exaggeration at a distance
from the Equator is so great that, beyond 50° or 60°, a circular or
polar projection is i^referable. The advantage of Mercator's projection
is, that the bearing and distance of one place from another, as measured
on the map, is the same as on the globe itself; the traveller can thus
lay down his route upon it with great readiness. The Conical Projection
is well adapted for the representation of small portions of the sphere ; but
if the map is extended much above or below the middle latitude, the
distant parts will be greatly distorted. The Rectangular Tangential
Projection is well suited for maps on a scale of 10 miles to an inch ; and
the tables published by the late Sir Henry James provide the means of
readily constructing the sheets required.
l:icale. — For the fair plan, a scale of 10 miles to an inch is recommended,
for the field sketch or outdoor-work, a scale of 2 miles to the inch ; or, if
much detail is required, of 1 mile to the inch. The scale of 2 miles to
the inch has this advantage — that the ordinary sketching-card 12" x 15"
will contain sufficient ground— 21 miles x 30 miles— for the day's work
and most of the points to which bearings are taken.
The classes of Survey to which attention may be directed are — 1. A
M 2
164 HINTS TO TRAVELLERS.
simple route-survey ; 2. A district-survey ; 3. A special survey of a small
tract of country ; and 4. A survey of a plot of ground containing rains,
&c. The only instruments supposed to be available are — sextant, watch
or chronometer, prismatic compass, measuring tape, aneroid, &c.
1. Houte Survey. — Arrived on the ground, the traveller must first fix,
with as much accuracy as possible, the position of some point on the
earth's surface to which his work may be referred. If he starts from
the coast-line, the position of some well-defined point can generally be
obtained from the Admiralty Charts, but if no such resource is available,
the position of his initial point must be determined by astronomical
observations. The latitude can be obtained by a good observer with a
6-inch sextant to about 100 yards on the earth's surface ; but the longitude
is seldom found by lunar distances to within ten minutes (10 miles on
the Equator). The position of the initial point. A, having been deter-
mined, work commences. The true bearing of some well-defined distant
peak, or other landmark, is obtained, and this having been made " zero,"
a round of angles is taken with the sextant to conspicuous objects, some of
which should be in the direction of the proposed line of march, and, if
possible, near the first halting-place. Several observations of the zero-
point are made with the comi^ass, the needle being deflected each time, to
obtain the variation, and the aneroid read for altitude. All angles should
be booked at once in ink, and the names of the observed objects carefully
noted ; a rough outline-sketch of the peaks or other landmarks will be
foiiud useful in identifying points as the work proceeds. The initial
point. A, is pricked off on the sketching-card in a suitable position for
laying down the day's march, and surrounded by a circle ; the observed
angles are plotted ; and a magnetic meridian is di-awn ; all is then ready
for plotting the route. The compass is set up at A, and the sights of the
instrument are directed on some object, V , in the direction of the line of
march ; the bearing of V is read off and plotted from A on the field-sheet
by means of the protractor ; bearings are then taken to conspicuous objects
such as X, which appear to Lie near the line of march, and these are
likewise plotted. The march now commences in the direction of A V , and
is continued to the point h, where the route is found to turn to the right ;
the distance A h, measured during the march, is laid down upon the field-
sheet, and the point h, surrounded by a circle ; the compass is then set
up at h, and the bearing of an object, c', in the direction of the new line of
SEXTANT AND PKISMATIC COMPASS SUKVEY.
165
march, read off and plotted from b on the field-sheet ; bearings are also
taken to objects, such as X, Y, on either side of the route, and plotted ;
the point X having also been observed from A, is now fixed. The march
is again taken ujd in the direction b c' until a point c is reached, at which
the road bends to the left, the distance b c laid down, and so on until camp
B is reached. At B, observations should be made in the evening for time
and latitude ; and in the morning, observations similar to those which
have been made at A. Should the camp be near one of the jDoints
observed to from A, the distance and true bearing of such point from B
should be determined, with a view of fixing its position. At certain
camps the longitude should be found by lunar distances, or other methods,
to serve as a check on the traverse-survey. Distances on the line of march
may be measured by counting or timing the paces of a man, or by counting
or timing the paces of a horse, mixle, camel, &c., whose length of step is
166 HINTS TO TRAVELLERS.
known. Timc-mcasnrement will be found mcst convenient, and, with
care, will give very good results. Compass-hearings need only be taken
at every second station on the line of inarch. 01)jects on either hand
should, where possible, be fixed by three bearings. It is not desirable
to take compass-bearings to points more than 6 or 7 miles distant, as the
prismatic compass can seldom be depended upon to within one degree,
and an error of this amount in 6 or 7 miles would give an error of 'OS inch
on a scale of 2 miles to the inch. If the route runs near a peak, of
which the true bearing has been determined from A, it should be as-
cended, and a round of angles taken with the sextant, making A the
zero-point. When there is a mid-day halt, the meridian altitude of the
sun should be observed. If a field-sketch cannot be kept uy>, the route
should be entered in a field-book, and afterwards plotted, before details
are forgotten. A book — with every alternate page ruled into squares by
strong lines, and subdivided by finer lines, the smaller squares represent-
ing five minute intervals of time, the larger ones one hour — will be found
of great use in making a rough sketch of the route ; or a modification
of the form used in booking a traverse-survey may be adopted. In all
cases the bearings, distances, &c., should be clearly written in the book.
In this field- sketch the ground has been treated as a plane siu'face, and
as soon as convenient the work should be transferred to the projection on
the fair jilan. In doing this it becomes necessary to calcialate the latitudes
and longitudes of the camps, and other jjoints, from the material provided
by the survey ; when this has been done, the fixed points are laid down in
their true positions on the maj), and the detail reduced to the i^roj^er
scale.
2. District Survey. — The basis of any survey of an extensive district
should be a system of triangulation, and the first step is the measurement
of a base line. With no instruments except a sextant, tape and prismatic
compass, the best plan is to measure an astronomical base, and thence
extend the triangulation as far as may be necessary. Two suitable points,
A and B, lying nearly north and south of each other, are selected as the
ends of the proposed base ; the position of A on the earth's surfi^ce is
detei'mined at the jjoiut itself, the true bearing of B from A is obtained,
and B having been made zero, a round of angles is taken with the sextant
to conspicuous points ; camp is then moved to the vicinity of B, and
observations for latitude made at that jDoint ; the true bearing of A from B
SEXTANT AND PKISMATIO COMPASS SUEVEY. 167
is then obtained, and a round of angles taken to the points previously
observed to from A. The length of the base A B can then be computed and
the position of several of the points observed to from A and B determined.
The fixed points are next laid down on the field-sheet, and the detail
filled in with the prismatic compass. In this way the triangulation may
be extended over the district to be surveyed, care being taken to
check the work occasionally by observations for latitixde at selected
points.
The following notes and problems* will be found useful in constructing
the map : —
Problem I. — Let A and B be two stations visible from one another,
AP = &, BP = a, their observed co-latitudes; the angles A and B their
reciprocal true azimuths; and A P B, or P, the required angular
difference of longitude. Then by spherical trigonometry —
Cot.iP=^^||±|tao.J(A+B)
which determines P.
Problem II. — The latitude and longitude of any point being known, that
of any other point within a short distance can be determined by i^lanc
trigonometry. Suppose the latitude and longitude of the camp at A to be
known, whence that of a neighboiiring peak or land-mark, C, is to be
determined ; the distance A C must be measured, and the azimuth N C A
observed, then the difference of longitude AB is the sine of A C B to radius
* Problems II.-V. are taken from Frome's ' Outline of a Trigonometrical
Survey,' revis'd by Major-General fcjir C. Warren, k.e.
168
HINTS TO TRAVELLERS.
AC, and the difference of latitude B C is the co-sine to the same angle and
radius.
Froblem III. — The distance between two places is generally resolved
by plane trigonometry, the difference of latitude S L, and the azimuth,
S'S L, called the course, forming a right-angled triangle, in which S S', the
distance, is determined : the other side L S', termed departure, being the
sum of all the meridional distances passed over.
DEPARTORE s'
Problem IV. — Given the distance travelled on a given parallel of
latitude to find the difference of longitude.
Again, in the triangle A B C, let A B represent the distance or departure.
SEXTANT AND PRISMATIC COMPASS SURVEY.
169
and the angles B A C be equal to the latitude, then A C, the hypothenuse
will be equal to the difference in the longitude.
Prohlem V. — Given the departure to find the diflference of longitude.
Also, if D B reijresent the distance, and C D the difference of latitude,
then BCD will be a right angle, and B C the departure, nearly equal to the
meridian distance in the middle latitude. If, then, in the triangle ABC
the angle A B C be measured by that middle latitude, A B, the hypothenuse
will be nearly equal to the difference of longitude between D and B.
For the variation of the compass, it is convenient to take a bearing of
the sun at sunset or sunrise ; or, if this cannot be done, an azimuth of
the sun at any time three hours before or after noon will answer equally
well. From the angular distance between the sun, when its own diameter is
above the horizon, and any well-defined peak, measured with the sextant
the true bearing can be obtained.
To find the sun's true amplitude for any day : — to the log-secant of the
latitude, rejecting the index, add the log-sine of the sun's declination
corrected for the time and place of observation. Their sum will be the
log-sine of the true ami^litude. If the true and magnetic amiDlitudes be
both north or both south, their difference is the variation ; but if one be
north and the other south, their sum is the variation; and to know
whether it be easterly or westerly, suppose the observer looking towards
that point of the compass representing the magnetic amplitude ; then, if
the true amplitude be to the right hand of the magnetic, the variation is
east, but if to the left hand, it is west.
170
HINTS 'i'O TRAVELLERS.
In filling in a survey, the observer can fix liis position, C, by observing
two fixed points, A and B, and plotting from those points tlie opposite
bearings to tliosc observed; their intersection fixes tlie point required.
The nearer the two bearings meet at a right angle the more correct will
the point be determined, and, if a third fixed point is visible, a bearing to
it will act as a check on the other.
A third and accurate method of fixing the position is by the angles
subtended between three known objects. The instrument called the
station-pointer is generally used for this purpose ; but the position may
also be found with a pair of compasses and protractor, or, more simply.
^^
as follows, by means of a protractor and a sheet of tracing paper. Draw
a line through the centre of the paper ; place the protractor on it near to
the bottom of the sheet; lay off the right-hand angle to the right, and the
left-hand angle to the left of the centre-line ; rule pencil-lines, radiating
from the point over which the centre of the protractor has been placed,
to the points that have been laid off; then place the paper on the plan or
map, and move it about until the thi-ee lines coincide with the objects
taken; prick through the point that lay beneath the centre of the
protractor, and the observer's position is transferred to the plan. When
possible, the centre object should be the nearest.
SEXTANT AND PKISMATIC COMPASS SURVEY.
171
Any object whose true bearing is ecast or west must be in the same
latitude as the i^lace of the observer.
Any object whose true bearing is north or south must be in the same
longitude as the observer.
3. S2)ecial survey of a small tract of country, with compass and tape
only. — First walk over the ground and examine it, with a view to the
selection of prominent points for stations, and of a level space for the
A B — Main line.
, jj j^ > — Principal triangles.
C c— Tie line.
measurement of a base. Having fixed upon a base, A B, set the compass
up at A, and take a round of bearings to B and other selected stations,
C, D, E, &c. ; then mark A on the field-sheet, in such a position as will
enable the whole sketch to go on the sheet, and protract the several
bearings from it. Mark A on the ground with a pile of stones or staff,
measure the base A B with the tape or by pacing, lay the distance down
on the field-sheet to the adopted scale, set the compass up at B, and take
172 HINTS TO TRAVELLERS.
a round of bearings to A, C, D, E, &c. These bearings are now plotted,
and their intersections with the bearings from A fix C, D, E, &c. ; in this
manner a rough triangulation is established, and a number of points fixed,
by the aid of which the detail can be filled in.
The paper, or field-sheet, for sketching with a prismatic compass,
should have parallel lines at unequal distances ruled upon it, to be
considered as east and west lines.
4, Survey of a jjlot of ground containing ruins, &c. — In making a survey
with a tape alone, we are confined to the simplest geometrical figure — the
triangle, as it is the only one of which the form cannot be altered if the
sides remain constant. In carrying out such a survey, divide the svirface
into a series of imaginary triangles, as large as the nature of the ground
will admit of, and attend to the following rules : —
1. Do not be in a hurry to commence work, but walk over the ground,
and make a rough eye-sketch of it on paper.
2. Select two points, as far apart as possible, visible from each other,
and commanding a good view ; let the points be near the boundaries of
the ground, and so situated that the line joining them forms a sort of
diagonal; this becomes the main line.
3. Select a point on each side of the main line, near the boundary of
the work, to which lines can be measured from each end of it, thus giving
two largo triangles ; then measure a check, or tie line, from one of the
vertices to a point at, or near the middle of the opposite side.
4. On the sides of these triangles, erect smaller ones to embrace all the
ground to be surveyed.
5. Measure lines from any station laid down, or from any part of a line
connecting two of them in directions most convenient for obtaining the
detail, taking offsets to such objects as present themselves.
The interiors of large buildings should be measured in a somewhat
similar way, by dividing them into imaginary triangles, and measuring tie
lines.
The great principle in all surveys is to work from a whole to the parts ;
errors are thus subdivided and time and labour economised.
PLANE TABLE SURVEYING. 173
The following symbols are recommended for adoption : —
Z 's signifies angles.
^ a station in the triangulation.
©
fixed by
■ latitude.
longitude.
® »
lat. and long.
<> "
true bearing.
>l .
right tangent.
K ..
left „
Surveying with the Plane Table.
(^For a description of this instrument, see p. 124.)
The first thing for the traveller to decide on, in commencing a survey,
is the direction and extent of his base ; and, as no special instructions
can be given for a base suitable for all sui-veys, it is a matter in which
he must exercise his own discretion, bearing in mind the following
points : that the length of the base line should not be out of proportion
to the distance of the points to be fixed, and that the fij'st jioints to be
fixed must be visible from both ends of the base line. The length of the
base should be accurately measured, or determined by observation. The
direction of the base line must depend on the positions of the points
to be fixed, as, when the angles subtended are either too obtuse or too
acute, a small error in the alignment will produce a large one in the
survey.
Having decided on a base line, call it A B (Fig. 1, p. 174), set up the
plane table over A, and arrange the board so that the direction of a h will suit
the jDOsition of the first portion of the survey. Level it by moving the legs
of the tripod, and using the circular level on the ruler. Clamp the table,
and mark a jDoint on the paper in any convenient position, to represent
A on the ground, call this a. Stick a pin in at a, and, placing the
fiducial edge of the ruler against this pin, turn the ruler about until the
other end of the base, B, can be seen through the slit on one of the alidade
sights, on the wii-eof the other sight, then draw a line along the fiducial edge
174
HINTS TO TRAVELLERS.
from a towards h, and take the distance from A to B with the compasses
from the scale on wliich it has been decided to construct the map ; set it off
on the line just drawn, and mark it h ; then a 6 on the board will represent
the base line A B on the ground. Now set the sights in turn on the other
points it is desired to fix, and, keeping the fiducial edge of the ruler
against the pin at a, dra:w faint lines to each of them. To prevent
mistakes, these lines, called " rays," should be marked with reference
numbers indicating the object to which they arc drawn, or the name of
each object should be written against the line drawn to it. Having done
this, place the compass on the table, and turn it about until the needle
points exactly to the centre mark in the compass box, which will be
Fig. 1.
magnetic north, then draw a dark line upon the paper, along the edge of
the compass box, which can be afterwards used for orienting the table as
explained (page 179).
Having drawn all the rays at station A, remove the table to station B,
set it up and level it in the manner before described ; then stick a pin at
b, place the fiducial edge of the ruler against it, and against a. Unclamp
the table, and tiu-n it about until the sights are directed on A, then
clamp the table, and it will be in a position to continue the work. The
process of pivoting the ruler against the pin, and directing the sights on
the objects to be fixed, is to be repeated precisely in the same manner
as at station A, and the points where the rays drawn from b intersect the
PLANE TABLE SUKVEYING. 175
rays drawn from a will be the position of eacli object on the map. Fig. 1,
p. 174, illustrates the manner in which the work is done.
To continue the survey by ohtaining fresh rays to objects from another
station.— First orient the table correctly, and find the position of that
station on the board.
By orienting is meant placing the table in such a position that the
north and south line on it shall correspond with the magnetic north and
south ; or, what is the same thing, so that the line drawn between any
two stations on the board shall be parallel to the line between the
stations on the ground.
The position on the board of the station at which the board is set up
can be found, and the board oriented in a variety of ways.
(1.) When the station has been fixed hy two rays from the ends of the base
or from other stations, all that has to be done is to place a pin in the
board at the station mark, lay the fiducial edge of the ruler against it
and against the mark on the board indicating the most distant station
from which a ray has been drawn, turn the board until the sights are in
a line with A, and clamp the board which is then oriented.
(2.) To find the joosition ivhen only one ray has been drawn to the station : —
Set up the table over the station to be fixed, say D (Fig. 1, p. 174) and
place the fiducial edge of the ruler along the ray that has been drawn,
say a, d, turn the table until the sights align on A, clamp the table which
will then be oriented. Place a pin in at b on the table and turn the ruler
about until it is aligned on B, and draw a line which will intersect the
line already drawn at d on the table, the position required.
Eepeating the last operation with other fixed stations will, if the lines
intersect, give certainty to the new position.
It may be mentioned that it is always preferable to choose a station
which has one ray already drawn to it, to fixing by any of the following
methods.
(3.) To find the position when no ray has been drawn to it, but ivith the
fixed 2Mints on the board, the following methods may be emjiloyed.
With three visible stations, ABC (Fig. 2), represented on the table by
ab c, the table can be oriented, and the position of an unknown point x
found.
First Method. — Fix a pin in the point b on the plane table, and
placing the ruler against it and the point a, with the object and sight
176
HINTS TO TRAVELLERS.
towards n, turn tho table about until the point A is intersected ; then,
clamping the table in this position, turn the ruler and intersect the
point C, with the edge of the ruler still against the pin at h, and draw
the line b m : — Now remove the pin to the point a, and unclamp the
tabic, place the ruler against tho pin at a, and the point b, and turn
about the table until the point B is intersected (vide 2) ; clamp the
table again, and, having intersected the point C as before, draw the
line a n. Through the intersection x> of the lines a n and b m, draw
Fig.
the line c 'p q passing through the point c, and, placing the edge of
the ruler against this line, unclamp the table once more, and turn it
about until the point C is intersected {vide 3) ; now clamp the table,
and it will be oriented, and the unknown point x will be situated on
the line c p q; to find this point it is merely necessary to place the pin
at a, and intersect the point A ; draw the line A a x. The accuracy of
the operation is tested by intersecting the other point B in the same
PLANE TABLE SURVEYING.
177
manner, and drawing the line B b x, wliicli should intersect the line A ax
on the line cp q, thus giving the position of x on this line.
When the point c, with regard to the point as, is situated on the other
side of the line A B or below it, the lines a n and b m will intersect on
the opposite side of the line a b, to that on which c is, and, if the point x be
situated within the triangle ABC, these lines (a n and bm) will diverge
instead of converge, in which case they must be prolonged in the opposite
Fig. ^.—{Good.)
direction until they intersect for the point p. The accuracy of this result
dejiends upon the length of the line c p.
Second Method. — Fasten a piece of tracing paper over the survey with
drawing-pins, stick a pin in at any point x on the table (Fig. 3), place
the fiducial edge of the ruler against it and point the sights in turn on
the stations ABC, on the ground, represented by a b c on the plan,
drawing lines towards yoii on each occasion until they meet at x. Now
take out the pins that fasten the tracing ]iaper to the board, and shift
N
178
HINTS TO ']'i;avi;i,i,kus.
it about until cacli of the linos ijasses tlirongh its corrcsiK^nding station,
as shown ou Fig. '6. I'rick through x, which will be your i^osition on
tho plan.
Fig. i.-iBad.)
In using this method, however, care must be taken to select objects
placed so that the centre one shall be the nearer, or the position found
may be considerably in error.
For example, a position obtained by this method from objects as in
PLANE TABLE SURVEYING. 179
Fig. 4 would be of little value, as x on the tracing paper could bo moved
considerably to the right and left without displacing the several lines on
the tracing paper oflf the stations a h c on the board.
For further information on this subject, see a pamphlet, ' On the
Station Pointer,' published by the Admiralty, and sold by J. D. Potter,
31, Poultry, E.G.
(4.) Orienting and fixiny by the Compass. — Set up the table over the
station X to be fixed, represented by x on the board (Fig. 5, i^. 178) ; place
the edge of the compass-box against a line drawn on the paper where the
needle pointed to north at one of the previous stations, imclamp the
table, and turn it about until the needle again points to north. Clamp
the table, which will then be oriented. Stick in a pin at a. Place the
fiducial edge of the ruler against it, and turn it until the sights point
to A on the ground; draw a line toAvards you by the ruler, and the
desired point will be somewhere on this line.
Stick a pin in at h, and with the fiducial edge of the ruler against it,
turn the sights on B on the ground, draw a line towards you by the
ruler, and the intersection with the line drawn from a will be x, the point
desired. Using C in the same way will prove the accuracy of the work.
Shiftijifj tJie Paper. — When one sheet is full and it becomes necessary to
replace it by a new one, to continue the survey, it may be done in the
following manner : — Draw a line through the farthest point fixed from
the last station. Take the sheet off the table and fix another on, drawing
a line upon it in a part most convenient for the work ; then cut the
sheet just taken off, by the line drawn on it ; apply this edge to the line
on the new sheet, and as they lie in that position, continue the lines from
the other station on the new paper, and prick through the positions of as
many stations that have been fixed on the old sheet as you conveniently
can. If the positions of three fixed points are thus transferred to the new
sheet, the place of a new station can be found in the manner shown in
Figs. 2 or 8. On each new sheet place the compass, and revolve the table
until the needle points to north, and then draw a dark line which will
represent magnetic north, unless the needle is deflected by the influence of
local attraction. The better plan, if provided with a watch and sextant,
will be to find the true bearings of some conspicuous object, in the
manner shown on i)age 236, and mark it on the table.
To joiji the sheets together, and thus form one rough ma^j, place the
N 2
180 HINTS TO TRAVELLEKS.
edge of the sheet that has l)een cut accnrately against the h'ne drawn
on the new slieot, and with the aid of the rnler, Koe that the line
projected on the new sheet from the last station (on the sheet that
has been removed), is an exact continuation of tlie corresponding line
on thnt sheet.
Broken Survey. — The directions given above comprise briefly the
fundamental rules of more accurate plane-tabling.
A map, however, may be, and often must be, constructed without the
continuous connection of fixed points from sheet to sheet, as is above
suggested, and which, in the rough work of an ordinary journey, is
frequently imiwssible.
The traveller may often find that the station from which he wishes
to observe rays is beyond the limits of his last sheet, and that none
of his fixed points will fall upon it.
In this case he must assume a convenient point on his board as his
position, turn the board in a suitable direction with regard to what
he wishes to do, and sighting, if possible, one of his old stations, draw
a line towards it. Should another former station be visible, another line
should be drawn to it. The magnetic meridian must also be drawn by
means of the compass. These three lines will enable him to place his
new sheet in proper relation to his former one, by arranging them with
the meridian lines parallel, and moving one until the continuation of the
lines passes through the two former stations. They can then be pasted
together in that position, joining them by another strip of paper, if
necessary.
Even should there be no fixed stations in view, rays dravra to objects
he wishes to fix will be useful, always supposing that he can afterwards
fix the position by rays drawn from other stations, never omitting to
lilace the magnetic meridian on the sheet.
New bases must occasionally be measured, and it will be found that
one of the chief charms of such surveying lies in surmounting difliculties
in the construction of the map. Devices for so doing will suggest them-
selves in increasing niimbers as the ti'aveller gains experience.
Though reliance on the compass should be avoided if possible, from
its uncertainty, owing to local attraction, recourse must frequently be had
to it, and under favoural)le circumstances, iilane-tabling by its aid gives
excellent results.
PLANE TABLE SURVEYING. 181
Concluding Remarks. — On leaving a station, the traveller, when possible,
should leave some distinguishing mark behind him, so that he may be
able to recognise it again. Where it is possible, as will freqiiently be the
case, he must carefully note the changes which take place in the
landscape during his march; he will also do well to write on the plane
table sheets the native names of such hills, or conspicuous objects, as
he may have fixed on the table, as natives generally know these oI)jects
again when viewed from another station, which, from their changed
appearance, a stranger would be very unlikely to do. Paper mounted
on very thin cloth, and cut to the size of the plane table, will be found
serviceable, as it will not easily tear, and can be rolled up and kept in
a tin case until wanted. The traveller should also provide himself with
a waterproof case into which he can slip the plane table in the event of
heavy rain.
From each station draw in the features of the ground around it as far
as you are able. Hough sketches, made in a sketch-book, will help to
complete the drawing, and the work from other stations, when you have
obtained the rays from them.
A pocket (or box) sextant is a valuable adjunct for plane-tabling, as in
certain cases the objects may be so crowded in one direction as to confuse
the rays if they are all drawn on the board. Angles measured and
recorded in a note-book can be plotted hereafter when working up the
plan in the tent.
The scale on which to work must depend entirely on the nature of the
country, and the objects in view. For a small tract of country, with
much detail, one inch to the mile is good. For more extended areas
two or four miles, or even more, to the inch is sufficient.
Remarks on the Plane TahJe. — By Lt.-Coh B. H. Oodwin-Ansten, F.R.S.
The Plane Table is one of the most useful instruments that an cxj^lorer
can take with him, and the most accurate for the large areas of country
he usually has to deal with ; not of the small size constructed in this
country, but one similar to tliose used in all extended survey operations
in India. Its excellence lies in simplicity, which recommends it strongly
for the traveller or for reconnaissaacc work. All additions made to it,
182 HINTS TO TkAVELL-ERB.
all attempts at converting it either into a theodolite, or a level, detract
from its value, its portability, and possibility of repair if damaged. It is
a siiii])lo table and nothing more, and if required to be kept out of sight
will ])uss as such in the eyes of inquisitive natives — complicated brass
work readily excites suspicion, from the fact that they do not understand
what use it can be for, and any attempt to explain matters only increases
their distrust.
A plane table, 2 ft. G in. x 2 ft., can be made light, of good seasoned
deal (])aiiclled). The traveller should take two of this size, and have
his pai)er properly projected, with latitude and longitude on a scale of
8 or ]() miles to the inch, the former of which will embrace an area
of 232 X 184 miles, leaving an inch margin, although a plane talile
can be woiked up to the extreme edge. On this scale I have worked
successfully in Assam and the Naga Hills, and for fixing the jwsition of
peaks and hills, &c., at long distances it is invaluable. The tripod-stand
is available for the other instruments, but even this is not required on
all occasions, as a temporary tripod-stand can be made in a few minutes
with three sticks tied together in the middle.* Even when the atmo-
sphere is too hazy to see distant objects, or the traveller is passing
through a forest-country, traverse work with prismatic compass can l>e
projected upon the plane table, or the astronomical positions plotted in,
and the plane table work resumed as soon as circumstances }")ermit.
Better still than using a prismatic comj^ass, is to gum a fresh sheet of
paper by its edges upon the plane table, and on some convenient
scale, say 1 inch to the mile, the route can be sketched by back and
forward rays, and setting the plane table by compass. This route-sketch
can then be reduced and entered on the smaller scale plane table section.
A far wider area of country is sketched in by this method than by the
use of the prismatic compass, an instrument which cramps the observer
(es]iecially a young one), so that the result of such surveys is generally a
long line of route with but little work on either side, and that little con-
fined to a mere mile or two. It is improbable that error will creep into
the plane table work; whereas a few errors in recording prismatic compass
* AVlien surveying the Bhutan Himalaya from Darjiling to Punakha, after
losing my piano table stand in tlie snow, cro.ssing the Tegong-La, I worked on
very well with such a stand for several weeks.
PLANE TABLE SUKVEYING. 183
bearings or distances can never be corrected, often never discovered, unless
the ground is gone over again. The plane table sketch is made on the spot,
the country is put in as seen by the eye at the time, and when the tra-
veller reaches camp, or his breakfasting-place, he can ink it in. If he be
travelling in a dangerous country, where he may have to leave any of his
equi]iment, and make for some other place — not an unlikely contingency
at times — he has only to keep a copy of his work on tracing cloth, tilling
it in from time to time to carry in his pocket. During the year of the
Indian Mutiny, when working in the Kashmir territory, under circum-
stances which rendered the survey liable to be stopped at any moment, we
followed this plan by Captain Montgoinerie's order, and, had anything
hajipencd, not a square mile of country finished would have been lost.
I do not think that the accuracy of plane table work, or the rapidity
with which it can be done, is known and appreciated in this country.
To show its accuracy, 1 once tested it over about 80 miles in direct line
on the scale of four miles to the inch, when carrying the triangulation
across the Naga Hills from Assam into Manipur. I worked with a piano
table, and fixed the points on it, at the same time sketching the country,
and it proved wonderfully exact Avhen the triangles came to be computed,
and the trigonometrical stations ijrojected on it. It does not take longer
to set lip and conuuence working on a plane table than to get out a
prismatic compass. About four times, or more, the number of bearings
can be taken with the Ibrmer than with the latter in the same time,
while the plane table bearings have the merit of being absolutely true,
and are all observed, and laid down the next moment, with a stroke of the
pencil, and after practice almost in the exact position on the pai>er. No
set of angles laid off with the best protractor can be so accurate.
The different value and extent of the work in Afghanistan, and at the
Cape, executed during the late campaigns, shows conclusively the value
of plane table survey over the prismatic compass.
As a practical illustration : — Working at the same time with an oflScer
of the Quartermaster-General's Department on service, making a sketch
of a fort and country round, my plane table survey was finished and
traced off when he had only begun the plotting in his tent. The run of
the mountain-spurs around such a position could never have been entered
on a plan produced from a field book.
There is no measuring, no counting of paces or noting of time by
184 illNTS TO TRAVELLERS.
a watcli, no auxicty about the record, when plane-tabling. Between
the intervals of setting up the board, the traveller can be botanizing,
geologizing, or collecting objects of Natural History, and in the evening,
when he comes in from his work of the day, he can sort and label his
specimens and write up his journal, the greater part of which leisure time
he would have to give up to the plotting of the day's work, if done with
prismatic compass.
One of the objections often brought against the use of the plane table,
is its size and weight. This would be true if the traveller had to
carry it himself. According to my experience in Asia, and what I
know of Africa, where laboiu- is, as a rule, plentiful and cheap, a plane
table 'can always be carried by a native of the country, who at the same
time would take the aneroid and boiling-point thermometers. In India
the giiides often carried the stand. It is seldom that a European is called
on to carry anything in a tropical country. The plane table can be
made as light as a gun or rifle, and reduced in size (2 ft. x 1^ ft.), together
with a light tripod-stand, could be carried by any lad of 15 or IG, as was
formerly the method of instruction at the E. M. C, Sandhurst.
Another objection raised is the possibility of its getting spoilt by wet.
This is very easily avoided. It should slip into a waterproof bag, and
if used in a very wet climate, such as the Khasi Hills, a small water-
proof sheet can be thrown over all. After working with it for years, and
having sketched many thousand square miles of every kind of country
from dead level plains to the highest parts of the Himalaya, I never got
one injured, and I never had one brought in by any of my assistants spoilt
or injured in the least.
There is nothing about it to be broken, or get out of order, the sight-
rule is of so simple a construction, any village blacksmith can make one
should it get lost; and I once had to do this, cutting out the woodwork
myself, and getting a native workman in the village to make the back
and forward sights out of copper coins. The staud is easily repaired.
The traveller should take a spare clamping-screw, and a spare compass.
The compass-box should be of narrow oblong form, having a perfectly
plane surface beneath, so as to lie flat on the board, not fixed to the
plane table (as was done in the Sandhurst pattern). The needle should
be at least 4 inches in length, and the north and south ends of the compass-
box should have an arc graduated a few degrees on either side of the central
SURVEYING WITH THE TACHEOMETER. 185
line. At the first station where the plane table is set np and adjusted by
the surrounding projecting points or the first rays taken, the compass-box
is to be placed on some convenient part of the plane table, and moved
until the needle points exactly to the centre division of the graduated
arc. A pencil line should then be drawn along one side of the comjDass-
box, against which line it will always have to be laid when setting up the
plane table by it.
But here I may call attention to another strong point in favour of the
plane table, and that is, that it can be used quite independently of the
compass, in places where local attraction is great, and where, as I have
often found, the magnetic needle is quite unreliable, throwing the plane
table out many degrees, an error which would not be discovered if
working with a prismatic compass. With three fixed points on the plane
table, it can be set up in true position by interpolation (see jd. 175).
This method, however, should be resorted to only for filling in details.
For extended work, the plane table should be set up, wherever possible,
on rays taken from jjreviously fixed stations.
Surveying with the Tacheometeb.
(^For description of this instrument, see j). I'iO.)
The method of surveying with such a tacheometer as that shown
(page 121), is, as regards fixing positions of distant objects, the same
as with the jirismatic compass. This instrument has, however", this
advantage over the prismatic compass, that distant objects are seen much
more distinctly through the telescope, and the bearings can therefore be
more accurately taken than when the ordinary sight vanes, of the
prismatic compass, are used. In addition to which, the compass is
larger than the prismatic compass usually carried by the traveller. The
principal advantage of the tacheometer, however, will be found when it
is employed for fixing positions within comparatively short distances.
This is done by sending an assistant to the spot it is desired to fix, with a
staff such as is shown (fig. 2, p. 123), and with the micrometers, measuring
the angle it subtends when held (either horizontally or perpendicularly)
at right angles to the line of sight, at the same time taking the compass
186 HINTS TO TRAVELLERS.
reading throngli the prism. With the angle measured by the micro-
meters, if a ten-foot staff has been used, knowing the value of the micro-
meter divisions, the distance of the object can be at once obtained from
table XXIV. With the distance so found, and the bearinf,' which has
been taken, the position of the object can be at once laid down on the
survey by setting out the bearing from the point of ol)servation, and
tlien measuring the distance, taken from the scale f)f the map.
With any other length of stafi" than ten feet, table XXIY. (p. 307) cannot
be used, and the distance of the object will have to be computed. It is
usual when observing the angle subtended by the staff, to measure half of it
with each micrometer, the sum of which measures, will, of course, be the
whole angle subtended. The distance from the staif is computed in the
following manner : — Multiply the total number of divisions used in each
micrometer by the value of a single division of that micrometer, add the
results together, and this will be the value of angle in seconds. Divide the
length of the staff, in feet, by the angle in seconds and multiply the
result by the cosecant of 1" = 206265. This will give the distance between
the instrument and the staff, in feet.
Kxamph: — Length of staff, 12 feet; divisions used, Left Micrometer,
581*9, value of each division, 2""31 ; Eight Microm.eter, 5752, value of
each division, 2"04.
Uiglit Micrometer.
575-2
2"04
2joo8
1 1 504
Left Micrometer.
581-9
2-JI
5819
i"457
IT638
IJ44-I89
ft.
'/Og.
I-og,
. 2;i
. 12
7-6
= i'o';9i8i
= J -400986
1I7J-408
IJ44-189
The aiiglf in seconds = 25i-;.59'j
j-6'j8i9?
Cosoc. 1"^ 206265 Log. = 5-314425
Log. distance in feet, 98j-2 = 2-992620
The rod, though convenient, is not, however, absolutely necessary, as
distances can be measured by this class of tacheometer without it, by
making an assistant set up two staves at a carefuUy-iueasured distance
SURVEYlNa WITH THE TACHEOMETEE. 187
from one another, and at right angles to the line of sight. The angle sub-
tended by these staves is measured with the micrometers, and the distance
comiiuted in the manner already shown.
A tacheometer with ilxed hairs, such as described (page 123), may often
be used for measuring distances approximately when it is impossible to
read the markings on a graduated staff. This is done in the following
manner : — An assistant should be sent to the object, the distance of which
is required, and directed to place a staff in the ground. The surveyor
must then cover the staff with one of the fixed hairs in the instrument,
after which the assistant must move, very slowly, in a line at right
angles to the line of sight until he is covered by the second fixed hair,
when he might be stopped by some pre-arranged signal, and place another
staff there. He must then carefully measure the distance between
these two staves, whicli distance multiplied by the ratio between the
value of the hairs, which is generally 1 in 100, will be the distance of a
point, midway between the two staves, set up by the assistant, and the
observer. Thus, if the measured distance between the sfaves was 10
yards, the distance from the instrument would be 10 x 100 = 1000 yards.
Surveying on the tacheometer principle, but without a tacheometer,
may be carried to greater distances in the following manner.
Supposed a densely wooded plain over which it has been impossible
to preserve any record of the distance travelled, but with elevated
country at its extremities, the distance between points on the elevated
lands may be very accurately found by measuring a base on one at
right angles to the position on the second, of such a length that it will
subtend an angle of two or three degrees to an observer at the second
point ; and marking these ends either by choosing conspicuous trees or
other marks, or by flashing from them with a mirror, or by making fires.
The observer obtains the angle by a sextant or theodolite between the
ends of the base, and by simple riyht-angled trigonometry calculates the
distance.
187a hints to travellers.
Surveying a Country and fixing positions by means of Latitudes
AND Azimuths.
Thi.s sj'stcra of surveying cau be used with advantage in a country the
surface of which is so varied as to present several prominent and distant
objects.
In order to use this method the traveller must first prepare a [Mercatoi's
projection that will inchide the area he intends to map. The reason for
making choice of Mercator's projection is, that a line of bearing drawn on
it will intersect every parallel and meridian at the same angle, thereby
allowing all relative bearings to be readily and correctly laid down by
straight lines, which could not be done on a map on any of the other pro-
jections in common use. After having prepared his projection, a reference
to the annexed map will show the traveller how he should proceed.
The first thing to do is to fix the position in latitude and longitude of
the starting point A. This may be done by traverse, or bearings from some
object, the position of which has been fixed, or by one of the methods
mentioned in this book. Having done this, he should from the summit
of A, look for some prominent and distant object, in the direction he is
about to travel, such as the hill B on the map, and find its true bearing
by measuring its angular distance from the sun by the method shown
(p. 236). If a sextant is used all such measurements must be reduced to
the horizon, as sliowu in the example p. 238. "When a transit theodolite
is emi)loyed no such reduction is required, and it will only be necessary
to make the hill B his zero point, and then observe the altitudes of the
sun, with the vertical circle face right, and face left, in pairs (as explained
p. 115), noting the times, altitudes, and horizontal angles. With the times
and altitudes he must compute the sun's true azimuth (p. 239), and by
applying the mean of the horizontal readings to this, he will obtain the
true bearing of B.
The next step will be to set off, indefinitely, this line of bearing from
A, and the point B will be somewhere on that line. Having thus obtained
the true bearing of B, the true bearing of any object in sight can be at
once known by measuring the angular tlistance between it and B. Or,
if furnished with a plane-table, regarding B as the other end of the base
Tumei' A Shawe
J'ubUshAl l>y the Uovnl 4ie.npaj^hu\ti Sorifti in'Rints to Traveners",}893 .
SURVEYING BY LATITUDES AND AZIMUTHS. 187B
and drawing rays to each object, marking each ray in such a manner as
to prevent any future mistakes as to the object through which the ray is
drawn.
We will now sui^pose that the traveller proceeds in the direction
indicated on the map, meeting with obstacles which prevent his keeping
in a direct line towards B, and that he allows his watch to run down,
thus losing his Greenwich time, or the time of such other j^lace as he has
chosen for his reference meridian, and that after several days' march he
finds liimself in the vicinity of B. There he will have an opportunity of
fixing the position of B, finding the error of his watch on his reference
meridian, and by using this station (B) as one end of his base, and drawing
rays on his plane table through the points from which rays were drawn at
A, making a sketch map of the country through which he has passed. In
order to do this he must ascend B, and take observation by north and south
stars for latitude. The mean of results so obtained ought to be very near
the truth. Suppose, in the present instance, that the latitude so found was
5° N., then by placing the straight edge on that latitude on each side of
the graduated meridians, and drawing a line between those two points,
its intersection with the line of true bearing of B drawn from A, will be
the place of B on the map. Again, placing the straight edge on the point
of intersection of this parallel of latitude and the line of true bearing of
B fi-om A, and then moving it until it is parallel with the graduated
meridian, it will cut the graduated parallel in the longitude of B, which
in this case is 30° E. Knowing the latitude and longitude of B, the error
of the watch on the reference meridian can be found by the methods given,
pp. '201, 209, 210.
The weak point in this system of surveying is, that it cannot be
employed when the direction of the line of route apjiJioaches east or
west, as the angle between the parallel of latitude and the line of bearing
would be too acute to give satisfactory results.
188 HINTS TO TRAVELLERS.
SUKVEYING AND ASTRONOMICAL OBSERVATIONS.
Part 4.
ASTRONOMICAL OBSERVATIONS.
Necessity for Astronomical Observations.
A TRAVELLER merely passing through a tract of country cannot hope
to make more than a rough map of a belt extending a short distance on
either side of his path.
Upon the estimation of the length of his daily march, and of its mean
direction, his map will mainly depend.
The degree of accuracy of these two important factors will depend upon
his experience, upon the trouble he takes to find means of ascertaining
his speed, and upon his power of estimating the mean value of a course
made up probably of an infinite number of windings and deviations.
When isolated or other well-marked hills exist, he may, however, on
camping for the night, be able to get a bearing with his compass of an
elevation at or near his point of departure in the morning, which will
give a greatly improved value to the direction of his day's march.
It is, however, evident, that after a few days, e.specially in densely-
wooded country, his position may be very much in error, and hence the
necessity, if he wishes his map to be in any degree trustworthy, of fixing
his position from time to time by astronomical observations, by sextant or
otherwise.
These have two objects : to obtain latitude and longitude.
The latitude observations, hereafter described, are comparatively
simple, and, in the case of latitude by meridian altitude, depend solely
on the altitude observed.
Longitude observations are, however, more complicated, and, whatever
method is employed, require accurate local time* This can be found by
altitudes of the sun or stars at some distance from the meridian, noting
the time by the watch, and by these observations the error of the watch
on local time is obtained.
♦ An exception is the case of the method of moon culminating stars.
ASTRONOMICAL OBSERVATIONS. 189
By repeating the observation in the same spot after the lapse of a few
days, the daily rate of the watch can be obtained ; and, supposing the
watch to be in good order, and well taken care of on the march, this rate
will for some days afford a means of finding the difference of longitude
of any two places when observations for time have been taken.
The precise method of doing this will be hereafter described, but it is
not often that in an ordinary journey it can be employed, as it requires
a halt of several days from time to time, and, moreover, it is not easy to
ensure the watch from accidents.
The longitude is, therefore, more ordinarily obtained from lunars or
other " absolute " observations.
It must be remembered that in all observations with the sextant,
unless they are so taken as to eliminate the errors of the instrument,
great errors of result may occur.
With a sextant in good order and adjustment the errors are small, and,
if known, may be applied ; but the heat of the sun may induce tcm2)orary
errors, and shocks more serious and permanent errors, which, in some
observations, will have a disastrous effect.
The ordinary observations are : —
Sextant Ohservations.
For latitude . . . . Meridiau altitude of sun
,, „ star
Circum-meridian altitude of suu
,, ,, star
Double altitude of sun
For longitude .. .. Time by single altitudes of suu
„ „ ,, star
,, equal altitudes of sun
,, ,, ,, star
liUnar Observations.
For true bearing .. By altitude oC the sun
By observed angular distance of a ])eak, or any
other object from the sun
Telescope Observations : —
For longitude . . . . Occultations of stars by the moon
lOclipses of Jupiter's satellites
Moon culminating stars.
190 HINTS TO TRAVELLERS.
Observations of heavenly bodies with the sextant.
Before any good results can be expected from sextant ohservations,
the observer must be able to read the angles quickly and accurately;
the only way to become proficient in doing this, is by practising with the
instrument, esi^ocially at night, when the angles have to be read by tho
light of a lantern.
Methods of vUaining accurate rcstdls. — From the presence of the different
sources of instrumental error mentioned on p. 102, it is necessary, in
order to ensure accurate results, that observations should be taken so as
to eliminate them.
The precise methods will be described under the head of each observa-
tion, but the general principle is, that any altitudes for any pui'po.<5e
should 1)6 balanced by others taken in the opposite direction, either by
waiting until the heavenly body has travelled to the opposite side of tho
meridian, as in observations for time, or by observing another body on
tho opposite side of the zenith, as in meridian observations of a star for
latitiule.
Owing to the instrumental errors acting in different directions on the
results in each case, the mean of those results will be the true time, or
latitude, as the case may be.
For ordinary purposes of rough mapping, these niceties are not neces-
sary, but the traveller who wishes to obtain a good determination of
an astronomical position must pay regard to them.
To observe the altitude of the sun, rising an artificial horizon. — Fill the
trough of the horizon with quicksilver, and put on the roof. Put down the
suitable shades before the index and horizon glasses, set the index of the
sextant to zero (0°) ; then with the artificial horizon between yourself and
the sun, retire, looking into the horizon, until you see the sun's reflected
image in it ; look through the telescope collar, or ]ilain tube, and horizon
glass of the sextant at the sun itself; unclamp the index, and move it
forward. This will bring the reflected image down, follow it with the
eye until it slightly overlaps that in the horizon ; clamp the index, and
screw the inverting telescope into the collar (no time should be lost in doing
this, or the sun's image may pass out of tho field) ; then with the tangent
screw make the contact perfect. It is always better to bring the object
OBSERVATIONS VOU LATTTITBE. 101
down into the liorizon without tlie telescope ; by so doing time is saved,
and tlie unpractised observer is less likely to bo mistaken as to which limb
he is observing. The following rule will, however, prevent any such
mistake : — -In the forenoon, or when the sun is rising, if the lower limb
is observed, the images are continually separating ; if the upper limb
is observed, they are continually overlapping; and the contrary in the
afternoon, or when the sun is falling. When the telescope is fitted with
a dark shade to screw on to the eye end, it should be used instead of the
moveable shades. If a roofed artificial horizon is used, the sides should
be plainly marked, and it should be reversed at each set of three altitudes,
except ivhen equal altitudes are observed to find the error of the watch, in
which case the observations must be taken with the same side of the roof
towards the observer.* In placing the horizon on the ground it should
have one of the glazed sides of the roof in a direct line with the sun, so
that its sides cast no shadow. Any object seen in the mercury appears
to 1)0 just as much below the horizontal plane as it really is above it ;
all angles, therefore, observed in an artificial horizon must be halved,
after the index correction has been applied.
The foregoing remarks apply equally to stellar observations, the only
diiference being that no dark shades are required.
Observations for Latitude.
The simplest observation is that for finding the latitude hy nieridian
altitude of the sun, star, or planet. Some twenty minutes before apparent
noon, when the sun is observed, or before the time of meridian passage
of a star or planet, the observer should begin to take careful obser-
vations, reading the angles from time to time until the body has reached
its greatest altitude; this will be the meridian altitude, and the time
when it was taken will be apparent noon, if the sun has heen observed.
Latitude by Meridian Altitude of Sun.
July 12th, 1882.— At a place in longitude by account 70° 00' W., the
meridian altitude of the Q was observed in quicksilver to find the
* Tills is by way of precaution against irregularities in the glass plates ; and,
with a roof of known excellence, is hardly necessary.
O
Kr2
JIIMTS TO 'J'UAVHI,I,K1!S
liitilu(](.'. Tliur. bS'. Bar. 2'J G inclies. Index error — 2'. Observer south
of the 0.
H. H. 8.
Time of. A lip 1 11, .July i2tli .. o o o
W. Long, ill 'J'imc +4 40 o
G. App. Time, July 1 Jill .. 4 40 o
Alt. Q. in quickBilvur . . . . 1 14 49 2«
Index error — 2 00
Dccliiiatioii {V. i. NA.)
Correction
KcJuccd DccliiialiijiJ
21 57 56-8 N.
- 1 3T&
21 $(> 19 N.
Observed Altitud'-' . .
Kefraction — 1
Thcr. 88°, Bar. 29-6 ../
2)114 41 28
= 57 2J 44
- cx) J4
Var. in I lioiir (NA.) 20-99
Hours and mill, of (j. A. '1' 4-66
Semidiameter
Parallax . .
12594
12594
8396
Zenith Distance
Corr.
6o)97'8iJ4 Declination
= I 37*8 Latitude
57 2J 10
+ 15 46
57 i» 56
+ 4
57 J9 00
90 00 00
J2 21 00 .S.
21 56 19 N
10 24 41 S.
To^Flnd Time of Meridian Passuije of Star.
When a star is observed for hititude, it is necessary to find the time of
its meridian passage, either by tables (which give an approximate result),
or, where accuracy is required, by the following method.
At a place in longitude 30° E. required the mean time of the meridian
passage oi Aldehiran, on November 29th, 1881.
h. H. sr. s.
CaseCi.) R. A. of .<lW«6araM + 24* = 28 29 11
Sidereal Time at Mean Noon 16 J4 2
Approx. JM. T. =: II 55 9
M. s.
lib. Retardation i 48'ijl
55ni. „ 9 01/
1 57
II 5i 12
jo° E. Long., or 2b. Acceleration 4- 2c
Mean Tinio of Meridian ras.sago = II 5J n
Wbcii the ilar's 11. .V. is less (ban tbe Sidereal Time at Mean Noon, inercase it by 24 bonis.
OBSERVATIONS FOR LATITUDE. 393
At a place in longitude 60° W. required the mean time of the meridian
passage of Antares, on July 20th, 1881.
n. M. s.
Case (2.) 11. A. of ^nto'es i6 22 11
Sidereal Time at Mean Noon 7 5? 37
Approx. M. T. = 8 28 J4
M. .s.
8h. Retardation 1 i8-64-i
28ni. „ 4' 59/
60"^ W. Long., or 4h. Acceleration* — o jg
I 2}
Mean Time of Meridian Passage = 8 26 32
* Wlien tlie Longitude isAV. subtract the acceleration, when E. add it.
Latitude hy Meridian Altitude of a Star.
July 10th, 1882.— At a place in longitude hy account 70^ 00 W., the
meridian altitude of a Aquarii was observed in quicksilver to find the
latitude. Ther. 34^. Bar. 30 inches. Index error + 3' 10". Observer
south of the star.
Alt. of -JlJ in Quiciisilvcv 90 59 42
Index error + i 10
2)91 2 52
45 31 26
Refraction— Tlier. J4°, Bar. 30 — 00 59-5
True Alt 45 30 26-5
90 00 00
Zenith Distince 44 29 35-58.
Declination o 5J IJ'4 S.'
Latitude 4; 22 46-9 S.
When the meridian altitudes of a star above and below the Pole can be
observed, half the sum of the corrected altitudes gives the latitude at
once, withoitt any computation. When the Pole Star can be observed
the latitude is very easily found by the rule and tables given in the
' Nautical Almanac ' ; and as a fairly correct approximation without any
calculation at all, the corrected altitude of the Pole Star is the latitude,
if the star is observed when /3 and f, or still better, when ^3 and e Ursas
Minoris appear to the eye to be in the same horizontal line ; a method
which, as a roiigh observation, has the advantage of being indei)endont
of watch, tables, or 'Nautical Almanac'
o 2
194 HINTS TO TRAVETJ>ERS.
Circum-meridian observations, or observations near the Meridian.
A latitude by mcridiau altitude depends only on one altitude, the
highest observed, and as this is liable to error, being only one observation,
a more accurate result can be obtained hij takincj sets of altitudes on either,
or both sides of the meridian, and noting the time corresponding to each
altitude by a watch whose error on apparent time at place is known. These
altitudes are taken in the manner previously described, and the observa-
tions should be commenced at about a quarter of an hour * before the
heavenly l)ody observed comes to the meridian, and may be continued until
it has passed it by a like space of time. As the sun or star will be rising
very slowly, the observations should be taken with deliberation, at aboixt
minute intervals. Should the sky become overcast, the observations on
either side of the meridian can easily be reduced to the meridian altitude,
and this circumstance adds considerably to the value of this class of
observation, as the meridian altitude may be lost.
A latitude obtained by either the meridian or circum-meridian altitudes
of the sun, or stars, which are all on one side of the zenith, i.e. all either
to the north or south of the observer, is liable to considerable errors from
the existence of instrumental errors.
To get a more certain result it is necessary to determine the latitude
from the mean of results of observation of north and south stars, by
which the instrumental errors are eliminated, and a very exact latitude
obtained.
By north and south stars are meant stars which pass the meridian to
the north and south of the observer's zenith. If their altitudes are nearly
the same the exactitude of the result will be much increased, on account
of the elimination of errors of refraction.
Latitudes by stars of the same altitude north and south afford the
traveller a fair means of ascertaining the centering error of his sextant
for the altitude observed, which is one half the difference of the latitude
by the respective stars. When the latitude resulting from the star on the
equatorial side of the observer is less than that from the star on the polar
side, the correction for centering error will be minus, and vice versa.
* Very good results may be obtained from observations with a star half an
hour or moi-e from tlie meridian, if the local time be accurately known.
OBSEKYATIONS FOR LATITUDE.
195
8
^
^
ce o
o h
K . ^
1^ o
•s ^ i
coo
o (^T E-i
« s
O 1^
•+^ • ;
O n3 ^
tc5 O
C ■" CO
P , -1 "Tl
_0 M CM
O O
o
^:;3
o fi 2
00 ® «
O 05 CO
_vO ~^
~>vO
0^
to « C>
M i
8
S MO
'^ +
vO
-'2 8
C7-
0^
Uill
^ CO a^O^^J^30
r y^ ? ?
f "?
CC vO
^
y
0=0 »^
CO «
•^
J>
-S,"
eo N
~ +
1-=o
-0
-r
82
;7v
C-<s
s
n^
M,
^
N
^
»
1
^
CO
1
iT
»
CO
'l-O
?
■^
■«•
CO
^ «
-
n
c^
100
HINTS TO TRAVELLERS.
C^OC O •* I "-
I- ^ r^ 00 CO
cxT^b b I b
'/)
'Ay^
y.
>/-, «
-to
-r
T
'f-r
1^
-8
K-
T
00 1
''+
cog
00 M
t-
_ : o
? o ,: o
-5! -
■3.2
o«
|1
(2 S
fs;^
"^ o S
rence
wage,
must
Its in
.2
c
|l
o
ill
!= S hS
-J! ■
X ^
^^ o *^ —
„^
V ^ <—
S .2 ■£ 3
» " -1-
-=; 4^ o
.a C;
1
1.1
1|
H
•— '
'Z *j
N
••is i
I'-'P'S
= s
./3
& =5
h-,*
.£ ^'
f^
(^ ^ ■— s
ifci
*
*
1111
.5"
«
s"-^?
CO
■"" "" O
«.S?
• ^
? 6 ^ -
<: r^ '*^
f^
^
p^
P
ci o Si's
C-5
wisO
■/-: (D ~, *
It
b
irv
^
II
s,.s.
ojQ
« Tf
^
z
l°H
S-
o
-a
H
S 5 ?-3
i-
i=t-
«^
g-
5Q
»s6
t«
£2a
^ ^- = S .
•^5
1
igsp
«' ~^ w O
O
M
= i^-s2
g .3
ia
??
C3 y
irv o
■*
o
.s -^ "^
,a CJ
li
aj N "v •<r
S vOVDO
liyi
?^ri
f
T
^^s-:i
a
OBSERVATIONS FOR LATITUDE. 197
The following,' will illustrate the mair/::r in which this observation
is taken. Suppose that on the 1st of December, 1881, we wished to fix the
position of the Society's Observatory in Uxtitudc, by north and south stars.
On looking at the heavens \vc should see that y J'ci/Ksi and y Ccphtt were
well situated for that purpose, and with these stars' right ascensions and
the sidereal time at mean noon (taken from the ' Nautical Ahnanac '), we
sliould find that y Cephei passed the meridian, to the north, at 6h. 51m.
24s., and y Fegasi to the south at 7h. 23m. 57s., thus leaving an interval
of 32m. 33s. between the meridian passages. We should commence
observing altitudes of y Cej hei at 6h. B5m., and continue to do so until
7h. 5m. ; we should then turn to y Fegasi, and continue our observations
of that star imtil 7h. 40m. We should then compute the latitude by each
set of observations, and take the mean of their results as the true latitude.
This observation may be taken, at the same place, at considerable intervals
between the times of the two stars' meridian passage, and indeed days
have sometimes been allowed to elapse before the second set of altitudes
has been taken ; tl.e results, nevertheless, being quite satisfactory. When
possible, however, it is better that the two observations should be taken
consecutively, so as to ensure similar conditions of weather and refraction.
J.afifmh hi/ Douhh AUItmle.
When clouds i:)revcnt the altitude of the sun being observed at or
near enough to noon to obtain the meridian altitude, or when the sun
when on the meridian is too high for observation in artificial horizon,
the method known as double altitude may be very useful. This consists
in observing the altitude of the sun (or star) at two times differing not
less than two hours from each other. The latitude can be calculated
from these witli great exactness. The error of the watch or local time
is only required approximately.
li)7A
U1NT8 TO TKAVELLEUS.
o I- +
TJ
^
o
S3 «
O "TS
^ o
o
^ ^ '7^
o sh
^ .9 S
^3 -i2
►3 ^
.a ^
CO
o
CO
•^ ■= J-
-t^ -r^ +
o be
S 5
c ^
.0
■J3^ O r-
a
5fc
CSS c
o o
03
■5 -^ <
I -: 8 8
O
II +
jag
I '^ — ^ S = '5
~ - J2 5: 5 > «
= gs
« C.
£5
•*.H SS^
-•3 e c o _ j=
OBSERVATIONS FOR LATITUDE.
197b
S.+
w
S
03
<0
<C
X
-n
a
<
a
f^
CO
n
CO
CO
ir\
I^
^
,
H
►-vO
o
o
*■
—
o
1-3^
ir\
o
o
cr-
b
a
b
O^;^
b
O^
o
b
o
^
II :
" "2 i:
■a
a
is
O 1 N
o
c~
o
i;
-M
1-
o
t^
-1-
XT',
~ + ~
o^
+
■^
O C^><^
1-
^
o
a^
^\
< <)
t~ o
(^
o o^
tT
Cv-
a>c>
C<
g M o
o
t-t
^
SB
£
ff
—
Si
>-
-c
o
fc-
t:
y
ja
S
"S
— 1
u»
-1)
o
<!
■^
•^
.o
P
5
-c
■«•
Q
I + +
w N cA •«• Sac •<
<<
198 TflNTS TO TRAVELLERS.
Time.
Measures of time. — lu these pages reference is made to Mean, Apiiareut,
and Sidereal times, and it is possible that a few remarks on these
diftcrcnt measures of time may he useful to those travellers who have not
had the advantage of previous instruction. The first of these, Mean
time, is tlie easiest to understand, as it is that usually shown by watches
and clocks, and is reckoned by the average length of all the solar days
throughout the year. For the purposes of everyday life, the day is
divided into two periods of twelve hours each, and commences at
midnight. This is called the civil day, to distinguish it from the
astronomical day, w^hich commences at noon, and is counted through the
whole twenty-four hours from one noon to another.
Jpparent time is time measured by the sun, as, for instance, the time
shown by a sundial, and the difference between this time and the time
shown by an ordinary watch, is called the equation of time, or the interval
of time necessary to convert Mean time into Apparent time, or the
contrary.
Sidereal time is measured by the interval occupied by a star between
two consecutive passages over the same meridian, which is equal to
23h. 56m. 4"09s. of our ordinary, or mean time. It will thus be seen
that the sidereal hour is 9'83s. shorter than the Mean time hour, and the
Sidereal day 3m. 55" 91s. shorter than the Mean solar day. Tables for
converting Sidereal time into Mean time, and vice versa., are given in the
' Nautical Almanac ' and most works on practical astronomy.
To Jind a lost Date. — It will sometimes happen that from one cause or
another, a traveller may lo.se count of the day of the mouth, in whidi
case (if provided with a sextant, artificial horizon, and ' Nautical Almanac '
for the year), he may find it by one of the following methods : —
Find the latitude of the place by the meridian altitude of a fixed star
(for this it is not necessary to know the day, as a star's declination varies
but little). On the next day, at the same place, observe the meridian
altitude of the sun, from which find the true altitude, and subtract it
from 90° to get the sun's zenith distance ; then with the latitude found by
the star, and this zenith distance, the sun's declination may be found as
follows : — The difference between" the latitude by star and the sun's zenith
distance ec^uals the suii's decljuatiou. With the declinatiou thus found
OBSERVATION;^ FOR TIME AND LONOITUDE. 199
search pago 1 for the month in tho ' Nautical Ahnanac,' ami opposite the
declination that most nearly agrees with the declination found as above, is
the day of the month.
This method cannot always be used in thL^ tropics, unless the traveller
is provided ivith a transit theodolite, as the meridian altitude of the sun
will, at times, be too great to be measured with a sextant, when using an
artificial horizon; neither can it be used with any degree of certainty at
those periods just before or after the sun has obtained its greatest
declination, viz., June 21st and December 21st.
Another simple method of finding the lost day, is to measure with a
sextant the angular distance between the moon and one of the heavenly
bodies whose distance from the moon is given in the lunar distance tables
of the ' Nautical Almanac' This observed distance must then be reduced
to the ajipureiit distance in tlie following manner: — When the sun is one
of the objects, add the semi-diameters of the sun and the moon to the
observed distance, but when a star or a planet is observed the moon's
semi-diameter must be subtracted when the distance to the moon's far
limb has been observed, but added when the near limb has been observed ;
the result in each case will be the apparent distance. Then (since the
true and apparent distances cannot difier by more than the sum of the
corrections of their altitudes), with the apparent distance found as above,
search the ' Nautical Almanac ' tables for the nearest given distance (of
the same body) to it, opposite which will be found the day of the month.
It must be remembered that the hours given in the lunar distance tables
are counted from noon, when the astronomical day begins : thus ,Tnly 18th.
XVli., astronomical date, is July 19th, 3h. a.m., civil date.
Observations for finding the Time and Longitude.
These are of two kinds. (1) Observations which have for their object
to find the difference of longitude between the place of the observer and
that of a place whose longitude is known.
(2) Observations to find the longitude directly, without reference to
any other position on the earth, or, as it is termed, absolutely.
The first, which are almost solely used at sea, require, when the time
since the rate of the chronometer was last ascertained is great, a good and
carefully-guarded timekeeper, and is known by the name of " n,ieridjan
200 HINTS TO TRAVELLERS.
distance," or measuring the difference between the meridian of the phice
and that of the i)lace where the chronometer was last rated, whose longi-
tude is known. This method, wlicn applicable, is by far the Ijest, but in
travelling requires that a continuoiis chain of observations should be
taken' from the time of leaving a place whose position is known ; and as
a w^atch, carried either by a pedestrian, or on horseback, cannot be ex-
pected to keep an equable rate, the jwints where halts must be made for
rating must not be more than tive or six days apart.
It is therefore but little used in ordinary travelling, but, as it is of
great value on occasions, is described hereafter.
The sjcond method depends, in its various forms, almost entirely upon
the rapidity of the moon's motion in the heavens, and, while it gives the
longitude without reference to any previous observation, the result is
always more or less rough, unless a great many observations are made on
different nights, when the mean may approximate to the truth.
In any of these observations the true time at the place is required, and
the method of finding this will first be described.
To find Error of Watch ly Absolute Altitudes.
In finding local time by this observation it is not necessary that the
longitude of the place should be known with any great degree of
accuracy, as the Greenwich date, obtained by the longitude in time,
is only used for correcting the elements taken from the 'Nautical
Almanac,' and a considerable error in longitude wo aid not produce
any serious error in the declination or equation of time. The body
should be observed as far from the meridian as possible, because, when
nearly E. or W., errors, both of latitude and observation, produce the
least effects on the hour angle. As a general rule, this oUservation
should not be taken unless the sun or star is changing its altitude by at
least 6' in 1 m. of time. The readings of the barometer and thermometer
should be noted, but for an approximate result are not necessary.
July 5th, 1881, at a place in lat. 18° N., and approximate long. 14° W.,
when a watch, supjiosed to be 2 h. 20 m. slow of local mean time, showed
5 h. 30 m. A.M., the altitude of the Q. was taken in an artificial horizon to
find apparent and mean time, and the error of the watch on each time at
the instant of observation. Index error + 6'. Ther. 75°, Bar. 29"2
inches.
OBSERVATTONR FOR TIME AND r.ONttlTUDE.
201
H. M.
Approximate local time, July 4tb, allowinpl
for supposed error of watch J 9 5°
Long. 14^^ \Y. = + 56
G. D. App. time, July 4th = 20 46
Declination, July 5th 22 45 54 ^f.
Corr. by var. in i hour +46
Ucduceil Declination
Polar Dist
. . 22 46 40 N.
90 00 00
= 61 ij 20 N.
Kquation of Time, July 5th 4 ig'Ji
Corr. by var. in i hour — i • ;6
KeJuced Eq. Time
Observed Alt. Q in Art. ) .
Horizon .. } ^ 42 4°
Index Error 4- 6 o
Corr. Refraction
2 ) 60 52 40
^o 26 20
.. - I ii
Jo 24 49
Semidiimeter + 15 46
Parallax
True Alt.
JO 40 j;
+ 7
JO 40 42
Alt.
Lat.
P. D.
JO 40 42
18 00 00
67 1} 20
2)115 54 2
i Sum 57 57 i
i Sum— Alt 27 16 19
Sec.
Cosec.
Cosine
Sine
H. >[. s.
4 14 12 = Log. sine sq.
24 00 00
0-021794
0-0^5262
9-72481}
9-661068
91442917
App. time at place, July 4th 19 45 48
Time by watch 4- 12 h 17 jo 00
Watch slow on Apparent Time
App. time at place, July 4tli
Equation of time
15 48
H. M. S.
19 45 48
4- 4 i8-4
Mean time at place, July 4th 19 50 6-4
Time by watch 17 Jo 00
Watch slow on Mean Time
=: 2 20 6-4
AVlien tlie error of the watch on Greenwich, w on any other meriillan
and its daily rate, are known, the longitude may be found by absolute
altitudes of a heavenly body, as shown in the following examples : —
202
HINTS TO TRAVEI.LERS.
<. "S
?5
s g
S.S
-2 m,
a" s
o tS
•r; oo
i ^
s
eg
Is
o
("S^l
>'i
•A
«
a-
o
03 O
>-. o
-r
^
^8
■^
+
■^ o
vii
i~
r-
'A
^o
c>
<7>
o
i8
~5^
« r-
i;*^
~00
"
•^
N '^
«
CO N
•5,^
s,+
CP
•r
?l
?
;ti
?+
1-
1-
a
^ "^
O
O
■a i i-r
» »r*»r
^
i;^
ir\
3 .^ 5
r-co CO
■«-
" +
so 1
00
»^ ^^ ^*^
<^
^^ 1
■c 3 ~.
-^*^N^
o
~,
•^
^
- «;;
^
II
II
pi.
"j:
^ .^5
«
c>
«i3.a =
:7^
a
o
1
so ='=-'.5
■^
is
"S
u
C'^^^
o
63
oj ii;<^ >i
^
i
3
3
3
lote Tb
raction
>r by an
<! C5
OBSERVATIONS FOR TIIME AND LONGITUDE.
203
si
"^MSC
?"
"?
f
n O
?
«vO
II II
II II
^A
~\vO
f^
■«-
'J-'-
^
•^ •*•
P^
•" +
^^
sens:
C ^ e^ p.
H S !-«>
03 03
Sh
•< J fS X>
2a
204
HTNT^; TO TRAVRTJ.ERS.
'^
Si
s
-a
"
""
"3
o
tc
S
S
't-
S
'^
c-J
si
. o
e_a
§a
^^
OO u
<
s
■;■«
g^
i^o"
^
!-°
<
>»
■M L^
ti
s^
j= ja
s^
i^H
^
<»
ii
*
-1
c
o
5?
Ho
o
o o o
^
^a5
£
o o o
s
>^ M
•5
^
t^ f -I-
•s^ If >»^
p
V— v*/
a
«r"
■^
o
0"X> f
- %8
cr o
a
~
,
= ><
§i
IS
■s?
•/-o
3-
-f
J>
^^
o
^03
"
"^
~V
M ^
"
;S
?! ^
t.
J,
„
t^ 1
■^
^
^
•^
■"
"^
■" '
-
QJ
K-" W
„
„
^
M
•H
^
a
''^ w
M
"'
'^
w
■H
M
H
'^
II :
:
II
: ti
;|^
ti
*2
Id N
o -
;!
5
>>
J3
tj 2
3
S^
cS
flj 3
>
^
O 3
I?
=3 ^
S"'
O
s
H
II
J
1
-i
OBSERVATIONS FOR TIME AND LONGITUDE.
205
M6
c^M o
3 a)-i?
-r
<-)
OT
o
"
-r
V
P
cc
O
t^
•t-
K 3-0
•NJS.S
CO
•a
o t^ ••'
b "^ o
o a> ^
KM
.2 '? 3 H
, ai c -o ;
,,
,-
~ ;^
r» O
»^
O '^
vOO
00.^
<*-* 3
OK
■gS:?
3.^
§■^1
-■03 S 5
O !< 3 i _«
r°
t-
b u^
k
-">
VO
8 +
8
0) — .
^■s
rt a
^ o3
§S
1^
go
H^
'a. 3
_ .2
^ OJ
20
.?&
Sh
^K
206 HINT8 'J'O TRAVEI.LER8.
E(jaal Altitudes of the. bun, Star, or Planet. — In consequence ot instru-
menUil errors, time obtained by absolute altitudes is sometimes con-
siderably in error.
To eliminate these, it is necessary to observe e^ual ulliludes of the
lieavenly body — that is, to note the time when it is at the same altitude
oast, and when west, of the meridian.
Tiiis necessitates a halt of some hours, and, in the case of a star,
observation in the night and early morning ; but when time and circum-
stances are favouraljle, the result will always be more satisfactory than
absolute altitudes.
This observation must be commenced when the heavenly botly ol)Ser\ ed
is three or four hours east of the meridian. Having placed the artificial
horizon in its proper position, bring down the reflected image of the
object with the sextant until it is in contact with the image in the
horizon, then advance the index until it points to a whole degree — for
example, 40° — and, looking through the telescope at the image reflected
by the sextant mirrors, wait until it attains this altitude, note the tinu',
advance the index 20', to 40° 20', and wait until this altitude is reached,
Jiote the time; again advance the index 20', to 40° 40', and in like
Jiianner wait till this altitude is attained, note the time. Repeat this
operation as often as convenient ; nine such observations will be ample.
The heavenly body observed will, of course, at some time, have the same
altitude when it is west of the meridian, and this will be the case when
it is ahout the same interval, in time, from it. The observer must there-
fore watch until the last altitude taken is again furnished, note the time
when this takes place, and couple it in his note-book with the time when
the heavenly body had the same altitude on the other side of the meridian ;
move the index hack 20' and wait until this altitude is furnished, note the
time, and again couple it with the time when the same altitude was
before taken, and so on through the set, moving the index hack after each
sight by the exact amount it was moved forward Avhen the object was
east of the meridian, or rising. When an artificial horizon is used, equal
altitudes of a star should be taken in preference to those of the sun. for
as the images of the star are bxit small luminous points, there cannot be
any great error in the observation if the} are made to touch, while in the
case of the sun, exact contai-ts are by no means so easy to make The
computation necessary to find the error of the watch, by equal altitudes
OBSERVATIONS FOIl TIME AND LONGITUDE. 207
of a star, is extremely short and simple, and therefore best suited to the
ordinary traveller. As the declination of a star may, for the purposes of
this ohservation, be considered constant, there is no necessity to coniX)ute
the equation of equal altitudes, which must always be done in the case
of the solar observation. The number of minutes by which the index is
to be advanced or pxit back must depend on the rapidity with which the
heavenly body is changing its altitude ; it has here been mentioned as
20' to illustrate the manner in which the observation is taken ; but no
general rule can be given for this ; it is a matter in which the observer
must use liis own discretion. The same side of the roof of the artificial
horizon must always bo used for both sets of observations.
208
MINTS TO 'J'KAVKI;LKI{S.
g
o
O
"^ 'B
•x
be
»
p^
O
H-i
-T]
*«
k;
o
-^
^
hS'
o
'f.
t/j
55
K
cc
o-c
■«•
1-
^
tl
5 - O
a
o
+
8
-^1
^
1-
8
o 8
8
8^
= 5
34 P.
.5 <i
"S O
= L, ■9 P
ol
«
HI
!^
It b
^
ei "
8
~> 1-
^
>^.
-•
^
2"
00
^
w l-t
M
r«
,--^,--v
y DO
^
II
« 3 g
•3
■ji
^?^ in
^ . .
S
CO
sags
©
w
II
N ^-
X
^
«
rr
^
1
-< '•
-
r^
00
T
H
X II
5 : (g i:
OBSERVATIONS FOK TIME AND LONGITUDE.
209
T » ^ II
3=2-3 II
=s a c
<^ ^O _
2 fe '* a
03 ^ — I—
■^ ..2 3
a :; 1
--3 C3
-5 c^ S
6
^
s
.2 t.
■5 o
sa *-»
1
a =3
ic j3 z:
00 O j;^
^ O CO
' = 1
::; +
3 a,
^ -2-3 .0
be o -"^ u!
M ■§
•3 J
.9-3
>> 3 .ti
•5" i -3:?
^1
Si 5
I
O 2;
1^ o
210
HINTS TO TRAVELLERS.
To find the Error of the Watch ty Equal Altitudes of a Star.
Exnmple.—On August 10th, 1879, iu lat. 51' 22' N., long. 00' 10' W.,
Equal Altitudes of tlie star a Cy<jni were taken, when the watch showed
as undermentioned ; required the error for Mean Time at the place of ob-
servation when the star passed the meridian : —
Watch Times of Eqnal Altitudes. To find TiniP of Star's Transit.
H. M. s. Mun'li. lay. ii. M. .«.
a Ci/^rni E. of Meridian 8 4; 10 Star's R. A Viigust lolli 20 Ji 21-98
„ W. .. 1} 20 15 Sidereal Time. p. ii. X. A. ,, ,, 9 14 22-59
2)22 5 25 Time of Star's Transit at Place (nearly) 11 22 59'J9
10' \V. Longitude, in Time . . . . = +43
TlTie by Waich. of Star's!
Transit i -^ 4- ? Greenwich Date of Star's TransH (nearly) 11 jj J9-59
Mean Sun's R. A. To find Krror of Watch.
Month. Day. h. m. s. Month. Day. h. m. s.
.Sidereal Time, p. ii. N. A., August lo'th 9 14 22-59 Star's R. A. .. August lotli 20 i") 21-98
Aceleratijn i 11 h 4- i 48'42 Corrected Mean \ ,
f..rG. D. of |2;m 4- i'78 0's R. A. / " " ^ "* '
transit (2i) ( ^9 sec + o-ii
— ■ Corrected Date of Star's Trac- 1 ,, ..„p
Mean 0's K. A. corrected = 9 16 14-90 sit at Place i ^
Therefore NVatch should show 1 1
But it shows 11
Error of Watch on Mean Time at ;3Za<-fj _
when Star passed Meridian . . ••/""_
24- 58 slow
Equal Altitudes of a Star on tht same side of the Meridian, on different
nights. — Observe the altitude of a star at any time, note the time and
the altitude. After an interval of some days— for example, four days —
set the index to the altitude noted, and take the time when the star
attains it; then, as a star comes to the meridian exactly 3m. 55' 91s.
earlier every day, multiply this interval by the number of days elapsed,
and subtract the product from the time when the first altitude was
taken; the result will be the time the watch should show. Any diflference
between this result and the time the watch shows is the error for the
interval, which, divided by the number of days, gives its daily rate;
thus, if a watch showed 9h. 50m. 8s., when an observation of a star was
OBSERVATIONS FOR TIME AND LONGITUDE. 211
taken June 20th, and on June 2J:th showed 9h, 34m. 10s., when the same
star had the same altitude, its daily rate would be 3 • 6s. losing : —
H. M. S.
ist time 9 5° 8
J m. 55-91 sec. X 4 = i> 4?"6
Time watch should show 9 34 24'4
2n(i time 9 J4 10
Losing in 4 da j's .. .. 14-4 .•. daily rate i'6sec.
This observation should only be taken when the star has a considerable
altitude, so as to reduce the errors caused by refraction, and can only be
used when a halt of some days is made, as any change in latitude would
be followed by a change of altitude.
Rate.
It is but of little practical use to find the precise time of your observa-
tion unless it is transferred to the watch. By taking the difference
between the time resulting from the observations, and that shown by the
watch, the error of the latter is found.
The true time of any subsequent, or previous observation taken within
a short time of the observation for time, can then be found by apjjlying
this known error to the watch time.
If, however, the time is required some days later, it is necessary to
know the rate of the watch, and this is obtained by repeating the observa-
tion for time in the same spot after a few days, when the difference of the
errors, divided by the time elapsed between the observations, will be the
rate of the watch.
H. M. S.
Thus, Error of W^atch at Ujiji on 24tb Sept., 8 a.m., was i 14 2i elow
„ „ „ 29th Sept., 8 A.M., was 1 15 17 ,,
Difference 5) 54
Rate of W^atch = 10 -8 losing
Then, supposing that observations for longitude, say, by lunars, were
obtained on the 26th without being able to obtain observations for time
q2
-212 HINTS TO TKAVELLERS.
on the same day, the time can be found by applying the rate to the previou s
error, thus : —
H. M. S.
Wach showed iit time of observation for lunar about lo p.m. 9 i 50
H. M. 8.
Error of Watch on 24th = i 14 2?
2*6 days' rate = 28- 1 sees, losing .... 28-1
Error of Watch at time of lunar i 14 51-1 .. i 14 ii-i
True time at observation, 26tli 10 16 41 • i
Longitude by Meridian Distance.
The difference of longitude of two places is the difference of time
between them at the same instant.
If therefore you can transport the time at one place, by means of a
watch, to another jDlace, and obtain the true time at that second place, the
difference of those times is the difference of longitude between the two
places.
This is accomplished in practice, by finding the errors of the watch at
the two i^laces, either by absolute, or equal altitudes, and the rate, in any
case at one of them, though it is better to find it at both, and take the
mean.
The difference of longitude is then thus found.
Error of Watch at Mombasa,
8 A.M.
9 A.M.
erval 6
14th of Jul
20th „
04 days
H.
' . . . . 2
.. .. 2
18
I"
s.
J 2 slow
14 ..
Int
Difference =
6-04)
Daily rate =
I
18
■;3
12-91
gaining
Error of Watch at Taveta, 4 p.m., July 2;th 2 8 5 slow.
„ „ ,, 8 A.M., July ioth 2 6 48 „
Interval 4' 67 daj-s. Differences i 17
4-67) 71
Dally rate = i6-5 gaining
Former dally rate = 12*9 „
2)29-4
Mean daily rate 14" 7 „
OBSERVATIONS FOR TIME AND L0NC4ITUDE. 213
H. M. S.
Error of Watcb at iMombasa, July 2otli. 9 a.m. . . = 2 17 14 slow.
5 '3 days' mean rate — i 18 gaining'.
Error of Watch at Mombasa, July 25tli, 4 P.M. .. — 2 15 56 sl.w.
Taveta, „ „ ..=285
O / "
Meridian distance, or difference of l.onpitiide between) _ ,, _ . .- .-
Mombasa and Taveta '. I" 7 5i - \^JT ^^J^l
and as the watcli is less slow at Taveta than at Mombasa, Taveta is west
of Mombasa.
The Longitude of Mombasa bell fi J9 40 00 E.
Meridian distance, west i 57 45 W.
Longitude of Tavttii = }1 42 1? K.
Here we have supposed the rate to be obtained at both places. If,
however, it was only ascertained at one end, that rate would have to
be used. In the case supposed the result would be a difference of 10
seconds in the determination of the longitude of Taveta, or 2' 30" of
longitude.
This method can be used at any part of a journey to measure the
differences of longitude between two j)laces. If the longitude of one
of the places has been fixed by lunars, or other absolute methods, the
longitude of the other is known at once. If not, the longitude of either
of the places may be fixed hereafter, and the longitudes of the places
whose meridian distances have been measured will be in connection
with it, and not be scattered about with large individual errors, as
would be the case were they determined separately by one or two lunars.
Thus Consiil O'Neill, by means of a large number of lunars, settled, in
1884, the longitude of Blantyre, near Lake Nyassa, and any travellers
starting from this centre can, by means of a good watch, satisfactorily
determine the positions of places in connection with it.
Longitude hy the Occultation of a Star.
This is the best of the absolute methods of finding longitude, when
a sextant is available for ascertaining the local time. The following
describes the manner in which the observation is taken : — •
The moon in its monthly revolutions round the earth frequently passes
214 HINTS TO TRAVELLERS.
between the earth and a fixed star so as to intercept a spectator's view
of the latter; the disappearance of a star from tin's cause is called an
immersion, and its reappearance from behind the moon is called an
emersion. A list of these phenomena is given in the 'Nautical Almanac,'
with 'the limits in latitude beyond which a star cannot bo occulted Ijy
the moon. As the elements refer to the moon and star, as they would be
seen from the earth's centre, they serve equally for all places on the
earth's surface.
This observation is much easier, and more certain in its results, than
the lunar observation ; as the instrument (the telescope) is one that
every jierson can use, and is not liable to any error, all that is required
is that the observer shall be certain that one instant he does see the
star and that the next instant he docs not (with an emersion the exact
contrary is the case). Neither is there much difficulty in recognising
the star, its position with reference to the moon being clearly pointed out
in the ' Njiutical Almanac,' and as the moon only moves its own diameter
among the stars in an hour, there is ample time after the star and moon
are in, ajiparent, close proximity to make sure of the star. Before, or
immediately after this observation, a set of sights should be taken
to find the error of the watch on apparent or mean time at place.
"When a traveller has decided to observe an occultation, he should,
during the day, find the local time of that phenomenon, by applying the
assumed longititde in time to the G.M.T. of conjunction in IJ.A. of the
moon and star, which he will find among the elements of occultations in
the ' Nautical Almanac,' adding the longitude in time if it be Ead, and
suUracting if it be West. An hour before the time so found, he should
point his telescope to that limb of the moon by which the star will be
occulted; it is necessary to take this precaution as his assumed longitude,
and therefore his time, may be considerably in error. The moon will be
seen to approach the star from west to east, until its eastern limb will
reach the star and occult it; note the instant when this takes place.
After a certain interval the star will re-appear on the other side of the
moon ; note this time also. Either of these observations are sufficient to
determine the G.M.T., and thence the longitude, in the manner shown in
the exami^le. When the star is occulted by the moon's dark limb, the
observation will afford most decisive results. At or near full moon a
star occulted by the bright limb is not so easy an observation. The
OBSERVATIONS FOR TIME AND LONGITUDE. 215
description of a telescope suitable for this observation is given on
p. 235. The example given is computed by Eaper's rule and
tables. It will be observed that several of the logs can be taken at one
opening of the book, and as only four jilaces of decimals are used', the
log sines, cosines, &c., can be taken at sight to the nearest 30" ; this is
not, however, the case with the proportional logs ; where they occur the
strictest accuracy must be observed, and the decimals of seconds must
not be neglected. This remark also applies to the MoonV, Declination,
Eight Ascension, Horizontal Parallax, and Remidinmeter.
21 G
HINTS TO TRAYKLLER8.
in
"^
O xJ
5
o
!^S
>,
CM
S
■ S
J- t^
o
I^
f2(2
tn
CO
■ ^
- o
r*
o
o
tea
Ci
) *
pipi
-i
r-v
=4-1
NO
•^
e
C3
O
i CO CO
O
■*-.
_o
-k^
^1-
o
o>
'S
w
=G
o
^ f "♦■
o
S
o
<l
?s
C ^
o
e
.1^
(=,
§3
1
a5
O 3
S .
S fl
o
§ -^^
•rH 1:0
s a
I ^
CO fe
'^ CO
CO »i^
o o
zo
■^M
^
NvO
CO +
00
a o
r- = C
eo a
c<^e
•la
I a
•o '5)
•r.S 2
S •"
S o^
'^ '•^ 0)
►^-■=
*.s -^
§.9 2
t|.l
.5 o'o
is::
SaT 3
3 c
a: * *
ul 8 •?
bob
o u- N
1/-. 00
ebb
^
^S"
00
0-'
M -r
2 e:
»j-,
-
-1-
-r
?2,
s
~
-r
r::
-
°
::
c3 -_:"
t; 3-e: =
■- - b I V
I =
=: s
* =
= II
■^ ?8 I ?1
OBSERVATIONS FOR TIME AND LONGITUDE.
217
2+ I
*1
o I -
I II
o c>
b b
P ?
2 II
"S - b b~
I r* o^
I -^i-i
_a c
(5«
5 m
d a
00 oc O <:> rJ
■ ^ b b '-f 2
■•^ !*^
^.3 3
ir t^--- "^
s ^
uracy,
with
result
M.T.,
ds dif-
st ob-
s3
CS -t^ o
»-e-c 2 1- o
1^
—t o
Is^lii
■- P-^ 0) >■■■"
i»l
"21=^^^^
■?
^ «Bi
* iliii
5
a.s
218 HINTS TO TRAVELLERS.
Lunar Observations.
In this ohservation tlio observed distance is not only ]iaV)le to errors
caused by a defect of parallelism in tlie telescope, which always makes
the observed distance too great, but to all other instrumental errors,
some of which may very possibly be unknown to the observer, and as an
error in the distance, of whatever kind, produces about thirty times its
amount in longitude, it will be readily understood that but little value
can be attached to the results obtained from a single set of lunar
distances, even when the observation has l)een taken by a competent
person, as making the contact slightly above or below the centre of the
field, combined with the effects of irradiation, may very well caiase an error
of 20" in the observed distance, the effect of which would be, in average
cases, GOO" or 10' error of longitude. For these reasons lunar observa-
tions cannot be recommended to any person who has not acquired a perfect
knowledge of the use of the sextant, its errors and adjustments ; or who
is unable to remain at one place long enoiigh to take a series of distances
east and west of the moon.
To Measiire the Angular Distance bettveen the Moon and Sn7i. — As the
enlightened limb of the moon is always nearest to the sun, the angular
distance measured is always that of the near limbs; but since, on
account of her comi^aratively feeble light, it is necessary to observe the
moon by direct vision, and since the sun at the time of observation may
be either to the east or the west of the moon, the sextant has to be held
with its face up or down as the case may require. In north latitude,
when the sun is to the west of the moon, the instrument is held with its
face upwards ; but when the sun is to the east of the moon, it must be
held with its face downwards. In south latitude the opposite of this rule
must be followed. This is often much easier if the observer can hold the
sextant in his left hand; the position of the hand and wrist may otherwise
be cramped and almost painful. Before taking an observation, look at
the sun through the dark shades, and select those which reduce its
brightness in the greatest degree comi^atible with good definition; put
these down before the index glass; see that the inverting telescope
is adjusted to focus ; set the index to zero (0°) ; and hold the instrument
with its plane ijarallel to a line joining the sun and moon ; look at the
moon throi;gh the telescope collar and horizon glass, and move the index
OBSERVATIONS FOR TIME AND LONGITUDE. 219
slowly forward until the sun's reflected image makes a rough contact
with the moon, seen by direct vision through the unsilvered part of the
horizon glass; clamp the index^ screw in the telescope, and make the
contact perfect in the centre of the field with the tangent screw, moving
the sextant slowly round the axis of the telescope, hy which means the
reflected image of the sun will appear to pass the moon, and the accuracy
of the contact can be tested.
Betiueen the Moon and Star or Planet. — The angular distance between
a star or planet and the moon is always measured to the moon's en-
lightened limb, which is often the farthest from the star or planet.
When this is the case, the moon must be brought by reflection past the
star or planet before the contact can be made ; iu other respects the
observation is precisely similar to that already described, when the
angular distance of the sun is taken.
In observations of this class, the utmost attention must be paid to
accuracy, and a faulty habit of observation in making contacts of the
moon's limb with a star is not necessarily eliminated, as is very generally
supposed, and frequently stated, by taking distances east and west of the
* S'" I * S' * S"
M
moon. For example, if it is an observer's habit, in making a contact, to
place the star witbin the moon's disc, M, as at S', the distance S" S' is too
small, and the distance S'" S' too great; but sui^posingthe moon to be moving
in the direction from S' to S'", each distance will give too early a (ireenwicli
time, for each will give the time when the moon's limb was actually at S'.
When, however, the sun is the object observed east and west of the moon,
errors of this sort in observation, ■// constant, will be eliminated, since, as
the moon's enlightened limb is always turned towards the sun, such errors
would increase both distances and produce errors of an opposite descrip-
tion in the Greenwich time.* A single observation is of little value ;
* For further information on this subject, read the article on Lunnr Distances
in ' Chauvenet's Spherical Astronomy.''
220 HINTS TO TRAVELT.ERW.
distances should always be observed in sets, with stars east and west of
the moon, and as nearly equidistant from it as possible ; the observer
should also note which limb of the moon has been observed, and whether
the star was east or west of it. The more nearly the two bodies approach
the same horizontal plane, the easier will be the observation to take, and
distances between 45° and 90° will be least liable to errors in obser-
vation.
The thermometer and the barometer (or its equivalent, a boiling-point
thermometer) should be noted, and the refraction corrected accordingly;
because, if thermometric and barometric corrections be omitted, in
observations made on a high and heated plateau, there may be serious
errors in the results.
A comi^lete pair of lunars, made wholly by one person, consists of the
following observations, in ndditlon to those for latitude.
An hour before beginning to observe, get everything in perfect order ;
see that the lamp is well trimmed, its air-holes free, and that it is filled
with oil. Also rehearse the expected observations, that no hitch may
occur after they have commenced. Then let the hand and eye have
ample time to repose, and go on as follows : —
1. Kead thermometer in air.
2. Adjust horizon-glass, if necessary.
3. Two pairs of observations for index error.
4. Three altitudes for time, star e.
5. Three altitudes for time, star w.
G. Three altitudes of moon.
7. Five lunar distances, star e. of moon.
8. Five lunar distances, star "w. of moon.
9. Three altitudes of moon.
10. Three altitudes for time, star w.
11. Three altitudes for time, star e.
It is not absolutely necessary to take all of these altitudes, and it
may often happen tliat the traveller may be prevented by circum-
stances from observing the altitudes of the moon and the other heavenly
bodies, in which case they can be comj^uted as shown on p. 225.
For this purpose, however, it is necessary that the latitude of the
place, and the exact local time when the distances were observed, should
OBSERVATIONS FOR TIME AND LONGITUDE. 221
be known. The time can be found in the manner shown on p. 201.
The observation for time, the latitude of the place, and which limb of the
moon was observed, should be carefully entered in the note-book for the
convenience of the computer.
Clearing the Lunar Distance hy Baper^s Rigorous Method. — As this is
one of the shortest, and at the same time a strictly accurate method
of clearing the Lunar Distance, it is here given for the benefit of those
travellers who may not have Eaper's work in their jjossession.
Having found the Greenwich date with the assumed longitude in time,
and the mean time at i^lace by a watch, the error of which on local time
has been found by previous observation, reduce thereto the moon's hori-
zontal parallax and semidiameter, and if the sun be one of the objects
observed, take its semidiameter from the 'Nautical Almanac' From the
observed altitudes get the apparent and true altitudes; from the
observed distance get the apparent distance. Add to, or subtract fi-om
the apparent altitudes as many seconds as are necessary to bring them
to odd or even minutes, then add tliem together and subtract their sum
from 180°, and the remainder will be the sum of the Apparent Zenith
Distances.
Increase or diminish the True Altitudes by the same number of seconds
as were added to or subtracted from their respective Aj^parent Altitudes ;
add them together and subtract their sum from 180°, and the remainder
will be the sum of the True Zenith Distances.
Add together the Log-secants of the Apparent Altitudes and the
Log-cosines of the True Altitudes ; the sum, rejecting tens in the index,
will be the Logarithmic Difference.
Increase or diminish the Apparent Distance by any quantity of seconds
necessary to bring it to an odd or even minute (noting the number of
seconds) ; to this add the sum of the Apparent Zenith Distances ; take
Half the sum, and from this Half Sum subtract the Apparent Distance —
call this Kemainder.
To the Log-sines of the Half Sum and Remainder add the Logarithmic
Difference, and the sum, rejecting tens in the index, will be the Log-sine
square of the auxiliary arc x.
Arc X may also be found without any special table of log-sines
square in the following manner: — When the sum of these three logs
has for an index a number above 20, reject 10 from such index, and
222 HINTS TO TRAVELLERS.
then divide the sum by 2 ; this will give J the log-sine of the arc, which
multiplied by 2 will give auxiliary arc x ; this, of course, (.qqdies to
all cases ivhcre a lofj-sine square is mentioned.
Under x put the sum of the True Zenith Distances, take their sum and
difference and their Half Sum and Half Difference, add together the log-
sines of the Half Sum and Half Difference, and their sum is the log-sine
square of an arc, to which apply the same number of seconds by which the
Apparent Distance was increased or diminished to bring it to an odd or
even minute, subtracting them if the Apparent Distance was increased,
but adding them if diminished, and the result will be the true distance
nearly. Take the difference between the proportional logs in the
' Nautical Almanac ' against the two distances between which the
computed true distance falls. With this difference and the portion of
time just found, enter the table of corrections for second differences
(' Nautical Almanac ' or table 57 Eaper), and take out the seconds. ^Yhen
the proportional logs in the ' Nautical Almanac,' are increasing, subtract
these seconds from the True Dist., nearly; when they are decreasing, add
them, the result will be the M. T. at Greenwich.
OBSERVATIONS FOR TIME AND LONGITUDE.
223
«
(=^g
s - «
"^ ^^
^
s
en
an
■I s
^1
S3
(2-5
^
z
i "
=:
;:8
c;
X w
^
CO O
n o
c,
S ir-.
"
ra
a '^
a -t
vO I
•pasoddng
03 "^C^r-
r4 5 C3 •
i O O O - OD
« O ^ M ir
^ O N ca »r\ o
OS'S
p. o3 S a
u- r-
r4
ri
3
o
1^
o
:^
b >^
I
fr-
<;o
%+
CO
£ +
2:+
§-
1/- ••
y
O "^
r>A
o o
o
^ in
o
o
<lo
§,+
o
O 1
224
HINTS TO TRAVELLERS.
2-0
2 ts
c-o a*
M«5
CO V3 .=
II s
di.-5
•S g .11 I I
m •• — " ^ fe
a S
5 5
J5 tJ
d 2
'A to
1«>
(3 s
:^^
<f
1^
^•^
'~
t-t~
II
H5 ^^
o o o o
o> o
a«
-
3C
-*-
f^
H
M'
~
U^
I>
^
^
00
CO
c^i^
CT<
a. . 3 <u
CO.,"- 3
00
w N
12
^^
00 -"l-
1<;
Sp3
a- S
Mai
S a
a> >i ;—
« g So J
III 111! II
OBSERVATIONS FOR TIME AND LONGITUDE. 225
To compute the Altitude of a Heavenly Body,
It frequently happens that, at the time when a hinav distance is
required, the altitude of one, or both, of the bodies may be so high or
so lo'^ as to prevent their being taken in an artificial horizon, in which
case the altitude should be computed, the error of the watch on M. T.
at place having been previously determined; and since the Altitudes
employed in clearing the lunar distance are not required to the same
degree of precision as those used in finding the time, it Mill be sufficient
if they are computed within 20" or 30" of the truth.
Rule. — Having taken from the 'Nautical Almanac' the declination,
E.A., Sidereal Time, Semi-diameter Horizontal Parallax, &c., as required,
correct the same for the approximate Greenwich Date.
Find the Hour Angle as follows : — "
For the the apparent time from Noon is the Hour Angle. If p.m.
the mean time at place converted into ajDp. time with the equation of
time will be the hour angle, but if a.m. the apparent time thus found,
expressed astronomically, must be subtracted from 24 hours to give the
hour angle.
For the Moon, Star, or a Planet : —
To the Sidereal time at noon on the given day (page ii. N. A.) accelerated
for Greenwich date (table 23 Paper) add the mean time at place, tin's
sum will be the Eight Ascension of the Meridian ; subtract from the P. A .
of the Meridian the P. A. of the object, and the result will be the west
hour angle of the object ; which subtract from 24 hours when the east
hour angle is required.
The True Altitude may now be computed as follows : —
To find arc 1. — To the log cosine of the object's hour angle add the log
cotangent of the latitiide ; their siun (rejecting 10 in the index) will be
the log tangent of arc I.
To find the true Altitude.' — Add together the log sine of the Lati-
tude, the log secant of arc I., and the log cosine of the difference
of arc I. and the Polar Dist. ; their sum will be the log sine of the
true Alt.
N.B. — "When the hour angle is more than 6 hours, or 90°, take the log
cosine of the sum of arc I. and the Polar Dist.
22f) HINTS TO TRAVELLERS.
From the Triic Altitude to Jlnd the A2J2J'ire'nt Altitude: —
The corrections must be apijlied in reverse order, and with contrary
signs to those with which tlio true is derived from the Ai:)parent Altitude.
For the Sun or for a FUinet. — Subtract the Parallax in Altitude, and
add the Kefraction.
For a Star. — Add Eefraction.
For the Moon. — Take out the correction in Alt (table 39 Eaper), and
subtract it from the True Altitude of tlie Moon, this gives onhj the
apjiroximate ai)parent altitude ; en'er the same table 39 again with this
approximate apparent altitude, and take oiit the correction again, wjiich
subtract from the true altitude — the result gives the Ai:)parcnt Alt.
OBSERVATIONS FOR Ti:\[E AND LONGITUDK.
22-
«
^
o
2Pg
o 2
2 ^
9 '^
II
C5 52 p
■^ o
1^ ce
S o
CO "^
CO fl
CM 3
■S ft
« ^ •
O r" so
•r; '^ rS
o c S
,— +-' C'
^ " s
c
O
^ r^
CO >
<U cS
PI <X>
CO :5
cj
t- CD
- c5
£C .a S3
° fl o
bC e3 CO
to O "g
-^ s
o « i
o ^
-goo
9^ S '"
&c
o
r.
•f.
' .??l
r~
~ P
rS
1-'"
O
i-O
rJ O
T°
'-
^-
<=.e
32 I-
x?+ i
?J
C C .a
1:2 >
OS tj
s >-«
a 3 =
•5 ii 'So) g;
"3 a;
= ::+ i
o S
T O
+ II I
■3.<
\]
R 2
228
HINTS TO TRAVELLERS.
IS
O a
g a
I I ?-
^•2 ^
c? I + I c>
CO 00
b -
I I
O CO
r-j3
S^
\0 O "^
CC O^C^
_ 1- O
h-o =0
h6 <
OBSERVATIONS FOR TIME AND LONGITUDE. 229
Longitude by Moon Culminating Stars.
The observation can be taken with the transit theodolite, which must,
however, be accurately set up in the plane of the meridian. This can be
done by either of the following methods : —
By Meridian Passage of the Pole Star. — Find the mean time of the
meridian passage of the pole star in the manner shown on p. 193.
Level the instrument, and if tliis be carefully done the line of collimation
will move in a plane perpendicular to the horizon, and will pass through
the zenith, then by making it also pass through the celestial pole, and
clamping the horizontal plates when it is in that position, the movements
of the telescope will be restricted to the plane of the meridian. This is
done by turning the telescope on to the pole star, and covering it with
the point of intersection of the telescope wires at the time (previously
ascertained) of its upper or lower culmination, and then firmly clamping
the horizontal plates. The meridian line should now be laid out to the
north and south of the observer by sending a man with a lantern and a
staff" in both directions, and making him drive the staff into the ground
at the spot where the observer sees the lantern in a central position on
the cross wires of the telescope.
By High and Loiv Stars. — This method is accurate, and will be found
convenient when the i^ole star cannot be observed. Having placed the
instrument approximately in the meridian, choose two stars differing
considerably in declination, and but little in right ascension. Note care-
fully the time that each star passes the central wire ; take the difference
of these times, to which apply the rate of the watch, due for the interval,
and convert this into a sidereal interval by Eaper, table 23, or by the
' Nautical Almanac ' table of time equivalents. Take from the ' Nautical
Almanac ' the apparent right ascensions of the stars, and subtract the
less from the greater. If this difference agrees exactly with the sidereal
interval obtained by the watch, the telescope will move in the meridian,
but when this is not the case^ and the interval shown by the watch is less
than the difference of the stars' right ascensions, the telescope must be
moved to the west; if the contrary be the case the telescope must be
moved to the east. This must be repeated until the sidereal interval,
computed from the watch times of transit, and the difference of the stars'
right ascensions taken from the * Nautical Almanac,' agree exactly ; the
230 HINTS TO TRAVELLERS.
telescope will then move in the plane of the meridian. Select a star as
near the zenith as possible for the " high star," as when the instrument
is truly level the telescope will be on the meridian when pointing to the
zenith, no matter how much it may differ from the meridian when in any
other position.
Bjl Meridian I'assage of uni/ Star. — Any star may be used if the local
time is accurately known, and the time of the star's meridian passage
carefully computed (as shown, j). 122). The observation is precisely the
same as for the pole star, but it would be well to take more than one
star ill order to correct any errors that may have been made in observa-
tion or computation. Though the results of such oltservations as these
are susceptible of a gieat degree of precision, yet absolute accuracy must
not be expected.
By Stars East and West of the Meridim. — If local time is not accu-
rately known, the true meridian may be found in the following manner: —
Carefully level the transit theodolite, and set the 360° division as nearly
true north as you can get it by the attached magnetic needle, then clamp
the lower plate, and unclamp the vernier jDlate ; select any star at some
considerable distance cast of the meridian, and cover it with the inter-
section of the threads in the diaphragm, damp the vertical circle, and take
the reading on the horizontal plate; then, after the necessary interval,
watch the star until it is again covered with the intersection of the
threads in the diaphragm west of the meridian, take the reading, and
then the theodolite will point just as far west of the meridian as it
originally did to the east, and a jDoint midway between these two horizontal
readings will be in the true meridian. Care must be taken to k. ep the
vertical circle and the lower plate clamped during the interval between
these two observations. Having thus found the true meridian it can be
marked as previously directed. Owing to tlie constant change in the sun's
declination it is unsuited for finding the meridian by this method.
In the following : —
JR indicates right ascension of the heavenly body.
3)| ,, the moon's bright limb.
T' , ajiproximate longitude in time.
T ,, longitude in time.
C ., the difference of ^i?.
B ,, the mean of the second differences of ^U.
OBSEEVATIONS FOR TIME AND LONfllTUDE 231
The Observation: — Haviug the instrument set in the plane of the
meridian, proceed as follows : —
From the list of " Moon Culminating Stars," given in the ' Nautical
Almanac,' select the star whope transit you intend to observe, and calcu-
late the local mean time of its meridian passage in the manner shown on
p. 192. Take from the ' Nautical Almanac,' page IV., the moon's meridian
passage (upper), and from this subtract the time* of the moon's semi-
diameter passing the meridian, hefure full moon, but add it after full
moon, the result will be the mean time of transit of the moon's bright
limb ; but if the meridian of place of observation is at any great distance
from the meridian of Greenwich, or any other meridian, from which the
difference of the longitude is to be found, then it will be necessary to
correct this in the manner shown in the explanation of page IV., given at
the end of the ' Nautical Almanac' All this should be done some time
before the transits are to be observed.
If the instriiment is fittel, as it should be, for taking transits, it will
have four wires, one horizontal and three vertical, in the place of the
usual web, and the exact time of the contact of both the moon's bright limb
and the star must be observed at each of the three vertical wires, and the
means taken as the true time of observed transit. Be sure to be ready
at the instrument some time before the first object comes to the meridian,
and make a note of the difference between the declination of the moon
and the star, as when the moon transits before the star, it will only be
necessary to move the vertical circle by that amount to ensure the star
coming into the middle of the fie^l, but if the star transits first, its alti-
tude must be computed beforehand, and for this the latitude must be
known, thus : — Add together the complement of the latitude of the jilace
of observation and the declination of the star, when they are of the same
name, or taking their difference when of contrary names ; the altitude to
be reckoned from the south point of the horizon when the latitude is
north, and the contrary when south ; but when the sum exceeds 90° it is
to be taken from 180°, and the altitude is to be reckoned from the north
in north latitude, and the south in south latitude.
Having taken the observation, take the difference between the observed
mean of the times of transit of the ))] and ^ , this will be the mean time
interval ; accelerate this (Table 23 Eaper, or Time equivalents N.A.), and
the result will be the sidereal interval.
232 HINTS TO TRAVELLERS.
Put down the JR of the star observed, and under this put the sidereal
interval just found. When the moon transits before the star subtract
the interval from tlie star's JR, but when the moon transits after the
star add it, and the result will be the JR of the moon's bright limb at
transit at place, under which put the preceding Al of the moon's bright
limb, taken from col. 4 (N.A.) "Moon Culminating Stars," and take
the difference, which turn into seconds and decimals of a second, and
call C.
Take from the fourth column of the table of " Moon Culminating
Stars " (N.A.) the JR of the moon's bright limb for four successive
culminations, so that two may precede and two follow the JR of moons
liright limb at transit at place of observation ; jmt these below each other
in regular order, and subtract each of these quantities from the following
for the " First Differences," and called the middle term A ; subtract each
of the " First Differences " from the following for the " Second Differ-
ences," and take half the sum, or mean of the "Second Differences," and
call it B. The subtraction necessary to obtain the " differences " must
be made as in algebra, i.e., by changing the sign of the quantity to be
subtracted, and giving the result the sign of the greater quantity ; take
care to prefix the proper sign to B,
It should be remembered that the right ascensions of the moon's bright
limb, taken from the ' Nautical Almanac,' must be those of the same
limb (I. or II.) * as that observed. Near the full moon, when the limb
marked in the ' Nautical Almanac' changes from I. to II., there may be
one or two right ascensions not marked for the limb required. In this
case the requisite right ascensions may be found by adding to, or sub-
tracting from, the right ascension of the limb given in the 'Nautical
Almanac,' twice the sidereal time of the moon's semidiameter passing
the meridian (col. 7 " Moon Culminating Stars," ' Nautical Almanac '),
and the result will be the right ascension of the other limb.
To the constant log 4:'635480 (the log of 12 hours expressed in seconds)
add the ar-co-log of arc A expressed in seconds, and the log of C ; the
sum of these three logs, rejecting 10 in the index, will be the log of
approximate longitude in time, which call T'.
* The Roman figures I. and II. indicate the limbs of the moon which come
first or last to the meriiiian.
OBSERVATIONS FOR TIME AND LONGITUDE. 233
Enter table No. XXIII. (p. 305) with Bat the top, and the approximate
longitude in time, T', at the side, and find the corresponding correction, to
the log of which add the constant log 4"635480 and the ar-co-log of A,
and the sum, rejecting 10 in the index, will be the log of the correction
to be applied to the approximate longitude in time with the same sign as
B, and thus the correct value of T will be obtained, which will express
the longitude of the place if it be west of Greenwich, but if the longitude
is east we must subtract this value of T from 12 hours to obtain the
true longitude in time east of Greenwich.
This method, tchich is entirely independent either of local or Greenwich
time, includes all that is necessary to find the difference of longitude
between any two meridians where observations have been taken, but as
the elements in the ' Naiitical Almanac ' have been most accurately com-
puted, it is better to take Greenwich as the other meridian.
The jDrinciple upon which the longitude is found in this method is
similar to that which is used in a common hmar observation, and depends
on the observed motion of the moon ; but in the present problem, this
motion is ascertained by observing the time when the moon's bright limb
passes the meridian, instead of measuring the angular distance of the
moon from the sun, star, or planet. The variation of the moon's right
ascension, corresponding to a change of 15° in the longitude, is given
very accurately by the ' Nautical Almanac ' for every transit of the
moon's limb at Greenwich. This variation is about 2m. in time for Ih.
of longitude, and wiieu the difference of the times of transit under
different meridians has been found by observation, it is easy to obtain the
corresponding longitude.
234
HINTS TO TRAVELLERS.
Kxaiiqih .
November 28th, 1884, the transits of tlie ])| and the * e Piscium were
taken over three wires of a transit theodolite to determine the longi-
tude of the place ; the times being taken by an ordinary watch.
Transit, of ])|
H. M. s.
8 12 4';-T
8 ij oi'6
8 1} i6-6
J) J9 05-9
Mean 8 ij oi-gT
Obsd Local M. T. of Transit )
of 6 I'iscium ^
Obsd. Local M. T. of Transit /
ot j)| (
Mean Time I nterval . . . . =
Acot'leration
SiJcre.il Iiiterv.;! . . . . =
H. M. t
s 23 rt
8
U
01
97
o
lo
J?
76
+
I
••74
o
lO
it
•50
Transit of e Piscium
II. M. s.
8 2J 2J-9
8 2J J7'7
8 2J 516
{)
5r2
AltMM 8 25 !7'7!
isit ol ^ ^ov. 1
^'e.R <oL 4> o 56 5926
lanac) '
(ireenwiih Transit of
28th, 1884 {■
Nautical Almanac).
" I 's Transit before ^ (Sidereal 1 _
Interval) S
Ki of •i^l at Transit at I'lace = o
Pr. c dfng M of % (col 4 Nauti- / ^
cil Almanac) — S
Liifr. of M
c =
10 JT50
46 21-7^)
45 ;4"J9
oD_rrn
Nov.
2 preceding iE of 51 ^
2 following JR of 51 \
Day. 1884.
H. M.
S.
27th L. C.
iH
i5-4"
28th U. C.
45
54- !9
28rh L. C.
I I?
56-2;
29th U. C.
I 42
4,-88
+ 27 18 98
A.+ 28 01 -86
4- 28 49-')j
2nd DifT.
sees.
4- 42-88
4- 4T77
2) 90-65
B = 4-45:2
Constant Log
A expressed in seconds
1681-86 Ar. Co. Luj
sees.
C 27'J7-- ■■ I'M
sees.
Approximate T' .. .. 70J-0 .. = Lo
Correction 4- 7 ' 7
= 4-6ji4ao 4-6}548o
= 6-7742U 6*7742ii
Equation from Table.
— i-4?7275 o"-J Log. 0.477121
sees.
= 2-846966 Corr. 4- 7-7 = Log = 0-8868 12
Longitude in Time T = 710-7 = 2 57 40-5 West.*
* Th' Longitude is West because the Ji 's Jl at Transit at^ place is greater than the 5 's 51 at iho
nearest U. C. (upper culmination) at (Ireenwich (which in this case was oli 4;iu. 54- 39-1.). If the
5 's j?l at transit at place had been less than the nearest U. C. at Greenwich, the Longitude would
have been East.
OBSERVATIONS FOR TIME AND LONGITUDE. 235
'fu find the LoiKjitude hy Kclipsts of Jupiter's Satellites *
In the 'Nautical Almanac ' will be found the configiu-ation of Jujiiter's
i^atellites for every day in the year, excej^t when Jnpiter is so close to the
sun that ids satellites are invisible; these diagrams are given for north
latitude, and must be reversed for south latitude When Jupiter comes
to the meridian before midnight, the whole eclipse (both immersion and
emersion) takes place on the east side of the planet ; when after midnight,
on the u'rst side. As an inverting eye-piece must be used, this will
ii.ppear to be reversed. Tlie error of the watch on mean time at place
should be found from observations of the sun's, or a fixed star's altitude ;
but if Jupiter is more than '6 hours from the meridian at the time of
making the immersion or emersion of one of his satellites, and if Jupiter's
altitude be taken at the instant of observing the immersion or emersion,
the use of a watch will be unnecessary, as the 'Nautical Almanac' will
furnish the Greenwich date required ; this, of course, can only be done
when there are two observers. As a rule, the first satellite is to be
preferred, as its motion is more rapid than that of the other three. The
ix])lanations given in tlie 'Nautical Almanac' are so clear that they leave
notliing to he added.
The ubser cation. — Having estimated the local time of the phenomenon
with the assumed longitude, and the time given in the 'Nautical
Almanac,' be ready some time before the eclipse will take place, with a
telescope having a magnifying power of not less than 40, and note the
instant of the disappearance or re-appearance of the satellite. It mi;st be
remembered that either of these events (being caused by the shadow of
the planet) may take place when the satellite is at a considerable distance
from Jupiter. Ihe difference between mean time at place when the
observation was taken, and the mean time at Greenwich given in the
' Nautical Almanac,' is the longitude as shown in the following
exam]jle : —
Nov. 30, 1881, observed the emersion of the 1st satellite of Jupiter,
* " Tlii.s method, though easy and convenient, is not very accurate ; the eclipse
is not instantaneous, and the clearness of the air, and the power employed, affect
considerably tlie time of the phenomenon. Observers have been found to differ
40 sees, or 5U sees, in the same eclipse.'' — Eaper.
236 HINTS TO TRAVELLERS.
at 2h. 25m. 4sec., tlio error of the watch on local mean time being
36m. 33sccs. slow.
ir. H. s.
Time by Watch 2 25 4
Krror »t Watch + i'l ii
i I il
M. T. at Greenwich (' Naiuical Almanac ') lo 26 16
Longitude in Time 7 24 59 =; iii <) ■); w.
Observations for Bearings.
To find the True Bearing of a peah or any other object hy raeins of its
ohserved angular distance from the stm.
Observe the sun's altitude, then the angles between the object and the
nearer and farther limbs, and lastly the sun's altitude again ; noting the
times of each contact. If the object has any altitude observe it, and note
whether it is east or west of the sun. Half the sum of the times of the
observed angular distances is the mean time of the observation, and
half the sum of the angles observed is the apparent angle ; bnt if the
farther limb, only, be observed, the apparent angle is found by sub-
tracting the sun's semi-diameter; or if the nearer limb, by adding.
From the observed altitudes of the sun, the altitude at the time of the
observed angle is found by Simi^le Proportion.
"Witli time at place tind Greenwich date, either by the error and rate of
the watch, or with the longitude in time.
Take the declination from the 'Nautical Almanac' (if A]^}^. time is
used. Page I. ; if Mean time. Page II.) ; correct this for the Greenwich
date. From the observed altitude, find the True Alt.
I True Altitude,
Latitude,
Polar Distance ;
divide their sum by 2 for the half sum, and take the difference between
the polar distance and the half sum, which call remainder.
I Log secant of the Altitude, \
Loo secant of the Latitude, I rejecting 30 from
Log cosine 0/ i suni, [ the index.
Log cosine of remainder,
OBSERVATIONS FOR BEARINGS. 237
Take out the log sine square of the sum of these four logs (table 69,
Eaper), or divide the sum by 2, and it will give the log sine of half the
true azimuth, which multiply by 2 ; in either case the result will be the
sun's true bearing. If the observed object has an altitude,
I Log sine of 6b jecfs alt., \ .
Log sine of 0's app. alt., [ i"ejecling 20 from
Log cosec, of api>. angle, ) " '
and take out the siirn as a log sine : the result is the corrected angle.
If the observed object has no altitude, or if its altitude is very small,
this step is neglected, and the apparent angle is used as the corrected
angle.
Find the apparent alt. from the true alt. already found, from the
observed angular distance find the apparent distance, and from the cos
of the dist. from 0's centre, subtract the cos of the apparent altitude ;
the remainder will be the cosine of difference of bearings. If the sun be
East of the meridian, and the object more East, or the sun be West, and
the object more West, add the difference of bearing thus found to the
0's true bearing. In any other case, take the difference between the
sun's true bearing and the difference of bearings, and the result is the
true bearing of the object.
"When this observation is taken with a transit theodolite, the object, the
bearing of which is required, is made zero before taking the altitudes, and
the horizontal verniers are read after taking each altitude. As this gives
the horizontal angle between the object and the sun, it will only be
necessary to compute the sun's true bearing ; and by ajJiDlying the
horizontal angle to this, the true bearing of the object is obtained, and the
latter part of the work given in the example will be unnecessary.
238
HINTS TO TRAVET.LERS.
Examph.
Cos difference of bearings
Cos apparent distance
Cos apparent alt. ot'-0-
July 15, 1881, r.M at place, angles and altitudes taken with a sextant
Lat. 51° 24' N., Long. 9' 39" W.
O Alt. in Quicksilver.
87 4; o->
I ime.
H. M. s.
J ij 18
Obsd. Angular distance of an
object. ° ' "
Ea«t of the Sun 109 12 10
Year. Month. Day.
\?,ii, July i; ..
Error of Watch . . . .
Month. Day.
G. M. T. July i;
n. Jl.
- ij
IJ 5
Obsd. Alt. in Quicksilver Q 87 45 00
Iniex Error — 2 10
Obsd. Alt.
Refraction
Semidiameter
Paralbx .
True Alt.
2)87 42 50
- 43 51
4; 50 2i
4^>
44 '> 17
Month. Day. ° ' "
Declin.itlon July 15th (Page ii.X.A.) 21 28 52 N
Correction by Hourly Diff.forGM.T. — i 17
North Polar Di-t.
21 27 iS
90 00 CO
= 68 n 25
O's True .Vliitude 44 6 17
Latitude 51 24 00
N. I'olav Distance . . 68 J2 25
Sec. o- 1458} 4
Sec. o- 204899
2)164 2 42
4 ^um
I Sum
.. .. = 82 I 21
N. P. Di.-t. li 28 56
Cos. 9'i42J4i
Cos. 9"
J2?4i
57865
6 Q '.-■ True Bcaring=Log. Sin. S luare (69")t)
= s. 66° J4' 45" \y
9-478
Obsd. Alt. Q 4J 51 2;
Semidiameii r + i; 46
Apparent Alt. ©
cb-erved angular distance of obiect from the near limb^ ^^ ^
o( the snn, corrected for Index einir )
O's Stmidiameter
+ 15 46
Distance f I om O's centre 109 25 46
Q's Apparent Altitude 44 " n
o /
Diffireiice of Bearings 6224
Co^ 9-52198?
Cos 9 856056
9-665927
Difference of Bearings* = 62 24
(* If the obsd. angular distance is greater
than 90°, subtract this Difference of " ,
Bearings from i8o°.) '^ *
True bearing of O S. 66 ;? W.
Object East of O ii7 ?6
True Bearing of Object S. 51 i E.
t Figures In brackets refer to the number of the table in " Paper."
OBSERVATIONS FOR FINDING ERROR OF COMPASS. 239
Finding the error of the Compass hy the 0's Azimuth.
The observation for finding the sun's true bearing and error of the
compass is the same as that for finding apparent time, with this
addition, that the bearing of the sun's centre, at the time of observation,
must be taken with a prismatic or other compass.
August 12th, 1881, P.M. at place, the following observntious were taken
to find the error of the compass : —
o / O /
Latitude 64 5 X. ncaring of (t) Jf. 71 6 W.
180 00
Times hy Watch. Alt. Q Ai-t. Horzn.
H. it. s. o ' " S. 108 54 W.
5 19 56 52 27 00 ■
5 21 54 52 J 00
5 2} n 51 41 20
})i6 5 I J) 15^ "I 20
Mean = ; 21 40 Mean . . . . = 52 ? 46
Error of Watch + 41; Inties Krror — + 2 00
G. M. T., August 12 5 25 5; 2)52 5 46
— ^^^^^— * When the
° ' " Ob.-d. Alt. ..26 2 5? true Azimuth
O's Declination, Augu-t 12 . . 14 52 8 N refraction . . — i 59 is to the left
Corr. by Hourly Diff. — 4 4 of the magnetic
" - 26 o 54 the vaiiation is
Reduced Declination '4 4^ 4 ^- Semi-diameter .. + ij 49 W. ; when the
90 00 00 ■ — true Azimuth
26 16 4 J is to the right
North Polar Distance . . .. = •;; 11 56 Pa'allax .... 4- 8 of the magnetic
■~"™~^~^^^ the variation is
Tine Alt .. = 26 16 51 East.
rj
Alt. . .
l>at. . .
N P I).
i Sum . . . .
iSum-N.l'.
= 26 16 51 Secant 0047J85
— (^ 5 00 Secant o"J59456
= IS n 56
2)i6s }i 47
= 82 46 5J-5 Cosine 9-099181
D = "J 34 57 '5 Cosine 9-996186
9-502208 = I.og. Sin. Square = S. 68 }i W. Q's Irue Azimuth
" S. io8 54 W. 0's Bearing.
Error of Compass = 40 16 W.*
240 HINTS TO TRAVELLERS.
On Observations with Theodolites or Altazimuth Instruments.
By General J. T. Walker, r.e., c.b., f.r.s., ll.d.
In the opening pages of these Hints, lists of instruments have been
given which travellers of little experience are recommended to provide
themselves with, and the sextant has been more particularly recommended,
as the traveller will have oi^portunities of practising with it under the
tuition of the officers of the ship which is conveying him to his destination.
The suitability of this instrument for observations, both on land and
sea, is thus a great advantage for any person who has not had an oppor-
tunity of learning the use of his instruments before starting on his
expedition ; and should he not have a sufficient knowledge of the methods
of reducing the observations and calculating the results, he will find the
simplest and easiest rules for his guidance in the several works on
navigation, which are specially devised to enable the reduction of ob-
servations with sextants to be made by persons possessing little or no
knowledge of the principles on which the rules are based.
But the extent of the regions of terra incognita in which inexperienced
travellers can operate with the greatest advantage is constantly becoming
more and more narrowed and diminislied, and geographical science now-
a-days frequently requires that the rough outlines which have hitherto
sufficed for her purposes, should not only be amplified and filled in, but
rectified by more exact and reliable observations. The traveller must, in
such cases, be provided with an instrument of greater capabilities than
the sextant, and he should have thoroughly learnt the use of this instru-
ment and the method of reducing the several kinds of observations which
may be made with it, before he commences operations. If he has no
better instruments nor greater skill than his predecessors, his results may
differ widely from theirs, but they will not be more worthy of confidence.
An altazimuth instrument — or a theodolite possessing a complete
vertical circle as well as a horizontal circle — is in many respects superior
to a sextant. 1st, it measures horizontal angles directly, thus avoiding
the labour of reducing oblique angles to the horizon; and a round of
several angles can be measured with far less trouble than with the
sextant, 2ndly, it measures small vertical angles of elevation or de-
THEODOLITE OBSERVATION'S.
24]
prcssion of objects which frequently could not be seen l)y reflection from
a mercurial horizon for the measurement of the double angle by a
sextant. 3rdly, its telescopic power is usually far higher than that of a
sextant, and is always much more effective, the instrument being held
steadily on a stand instead of loosely by hand. 4thly, it may be so
manipulated as to eliminate the effects — without ascertaining the magni-
tudes — of constant instrumental errors, such as eccentricity, collimation,
and index errors. And 5thly, the influence of graduation errors may,
when great accuracy is required, bo reduced to a very considerable ex-
tent by systematic changes of the zero settings of the horizontal circle.
The disadvantages of the altazimuth instrument as compared witli the
f extant are its greater cost and balk and weight; but in many instances
these disadvantages will be more than counterbalanced by its superior
capabilities.
The following table gives tlie relative cost, weight, telescopic power,
and precision of graduation of Messrs. Troughton and Simms' instruments
of both classes.
Instrument.
AVeight of 'Weight
with Box. of Stand
f7-incb(raUius)soxtaiit
\ Artificial horizon
j-inch (diameter) tran
sit theodolite . . .
^-inch „ „
5-inch „ „
6 inch ,, „
lbs.
~i
i to 10
Price Telescopic Eeadlngs of
Powers. Verniers.
Details.
22 10
79 o
31 O
-)0 o
5 to 10
14
10 to 16
I'
1'
jO"
pViihout transit axis
I level, and lamp.
rWilh transit axis
I level, and lamp.
Do.
The Messrs. Casella construct certain very light and cheap altazimuth
instruments, with 3-inch circles, power 5, weight Avith box 4 lbs., weight
of stand 3^ lbs. divided to 1', price under £20.
For astronomical observations the sextant is decidedly preferable to
very small altazimuth instruments, but the latter are to be preferred
for the measurement of horizontal angles and terrestrial elevations or
depressions.
The traveller must necessarily adapt his equipment to his require-
P'ients,and to the facilities he will possess for carrying instruments about.
s
242 HINTS TU TKAVKLLKUS.
llo may find it couveniont to employ a ecxtant for astronomical, and a
very siuall light altazimuth for terrestrial observations. But, whenever
l)ractical)lc, an altazimuth of moderate size, which may be used as a
universal instrument, would undoubtedly be the most convenient and
satisfactory.
Trigonometrical operations arc, as a rule, far simijlcr and more easily
reduced, and lead to more accurate results than astronomical olisorvations.
A continuous triangulation, or a traverse with measured angles and
distances, is necessarily imi)ossil)le when the ex])lorer lias to pass through
a country very rai>idly; but he may frequently remain for .several days
at one place, and may then have ojiportunities of greatly extending the
scope of his operations by executing a triangulation. Suppose him to be
in view of a range of hills which lie may not have an opportunity of
cx])loring, distant say 50 to 100 miles; he may have already endeavoured
on his line of march to fix points on the range by bearings, but from the
absence of prominent landmarks has found a difficulty in identifying the
points observed, and thinks he may have mistaken one hill for another
in consequence of their changes in appearance as viewed from positions
at some distance apart. If, during his few days' halt, he can manage to
do a little triangulation, he may fix the general outlines of the entire
range relatively to his halting-place with very respectable accuracy. Ho
has first to measure a base and determine by triangulation the positions
of three stations lying in a direction nearly parallel to that of the range,
and at distances of 2 to 5 miles apart ; then at each of these stations he
must measure the angles between the other stations and a series of points
on the entire length of the range.* Though no very prominent landmarks
* He .sliould make u sketch of the outline of the raugo in liis book of observa-
tious ; iuul as lie will probably bo unable tn ascertain the names of the hill
siniunils at such a distanco from tlicra, and many of them may have uo unnios,
he liad belter number them in the order in which they are observed, and refer to
llii lu always by these numbers, until he can coutidenlly replace a inuuber by a
name. Exaggerated sketches of the outlines of the ohjeets intersected by tljc
telescope arc frequently of use to facilitate identification on proceeding to the
next station.
Tile ])ositions of places situated within or beyond the range of hills which arc
invisible to tlie traveller, but are known to his native guides and assistants, may
THEODOLITE OBSERA A'J'IONS. 243
may be visible, still the telescope will show a imml)cr of objects — trees,
masses of rock, and peculiarities of the ground — sufficiently clearly to
J )ermit of their being recognised and identified at stations of observation
which are so close to each other ; and though the triangles will be very
acute-angled, the angles may easily be measured with sufficient accuracy
to give the distances of the points on the ranges from the stations of
observation with a small percentage of error, whenever the marks are
truly identified ; and as there will be two triangles to each point, and
therefore, double values of the side common to both triangles, any
mistakes — whether of identity, or of reading, or calculation— will be at
once shown mp.
Whenever a break of continuity occurs in the triangulation or travers-
ing, astronomical observations must be resorted to. Much may be done
by a judicious introduction of latitudes and azimuths, more i:)articularly
where there is considerable northing and southing, for then good differ-
ences of longitude may be obtained from the azimuths and differences of
latitude. A prominent peak, visible from great distances all round,
may be made to serve as a connecting link between regions which cannot
l)c continuously connected, by measuring its azimuth and distance from
a base-line in each region ; the addition of latitudes, at the azimuth
stations, strengthens the work.
The G-inch subtense theodolite hj Messrs. Troughton and Simms has
been much used in exi^lorations connected with the operations of the
Great Trigonometrical Survey of India, and given great satisfaction, being
sufficiently accurate for all desirable purposes, and not too heavy to be
easily carried. It is adapted for determinations of time and longitude
by the method of zenith distances, and also by that of meridional transits,
tlie former being best suited for the traveller when ho can only devote
a few hours to the operations, the latter when he is halting for a long time
at one ])lace ; the two methods lead to strictly independent results, so
that when both are employed they serve to check each other. It is also
well suited for latitude and azimuth observations ; in fact, it can be
be approximately determined by making a native point the theodolite, as a gun,
in the direction of the place and state the distance beyond or on this side of tlie
range.
s 2
244 HINTS TO TKAVELLERS.
cmiiloycd in any of the investigations which an cxi^lorcr may have to
undertake by means of astronomical observations.
It is specially provided witli a pair of micrometers in the eye-piece of
the telescope, for the purpose of measuring small angles, and more par-
ticularly those subtended by.objects of known dimensions, by means of
wliich the distance between the object and the ol)server is readily deduced.
The system of micrometers is movea])le through an angle of 90", so as to
]K'rmit of the measurement of either a horizontal or a vertical ol)ject.
Witli the aid of this ai)]iliancc, the instrument can be employeil in carry-
ing on a traverse without using any direct measuring ajiparatus, such as
a chain or perambulator, the distances to the back and forward stations
being determined by measuring the angles subtended by a pole of known
length, or between two poles at a known distance. In hilly and broken
ground in crossing rivers or other obstacles, and generally wherever a direct
measurement is impracticable, this method of procedure is most con-
venient. With one of these instruments a traverse of the line of country
])assed over by the British army in the Abyssinian expedition, was carried
from Adiserat to Magdala, a distance of nearly 300 miles, withotxi any break
of continuity, the daily rate of progress averaging 5 miles, and being
occasionally as much as 8 miles. The difference of latitude between the
origin and terminus as determined from these operations only differed
by about a quarter of a mile from the value determined astronomically.
Whenever a halt occurred in the movements of the army, the instrument
was used as a theodolite in triangulating, to fix the positions of all hills
and other prominent objects around the halting-place ; it was also used
for various astronomical observations.*
* These instruments being furnished with a pair of raicrometci's, wliich can bo
uscil either horizontally or vertically, are all the more valuable for astronomical
observations ; for the micrometers give two additional wires over whicli the stars
may be observed, and these wires can be set at pleasure to any distance from the
fixed wires in the diaphragm wliich may be best suited to the rale of movement
of the star. For pairs of observations — face right and face left — no reductions to
the centre wire are necessary ; and thus greater accuracy is obtained witli very
slight additional troulile of observing, and still less of computing.
THEODOLITE OBSERVATIONS. 245
Beraarks on the Manipulation of Altazimuth Instruments.
Observations with these instruments should always be made iu pairs,
with the face of the vertical circle alternately to the right and left of the
observer. Thus, supposing that in the first observation, or round of
observations, the face of that circle is to the right of the observer, the
telesco]^c should be immediately afterwards moved through 180^ in
azimuth, and turned over in altitude, which will bring the face of the
circle to the left of the observer, and then a second observation, or round
of observations, should be taken ; the mean of the two measures, face
right and face left, will be free from coUimation, index, and other instru-
mental errors.
In measuring horizontal angles between objects of nearly the same
altitude, as landmarks not much above or below the horizon, a change of
face is not absolutely necessary, and may be dispensed with if Ihe observer
is hurried ; but when such angles are measured between objects of very
different altitudes— as a terrestrial referring mark and a star — and when-
ever altitudes are measured, whether of terrestrial or celestial objects, the
observations should invariably be taken in both positions, alternately
" face right" and "face left," and the final result deduced from the moan,
in order that the instrumental errors may be eliminated. There is no
necessity to determine the magnitude of these errors, as in the sextant ;
in an instrument which has to travel far over bad ground the adjustments
are liable to alter from time to time, but they are not likely to alter in
the interval between two consecutive observations, and the errors arising
therefrom will be eliminated in the mean of the pair.
In what follows regarding astronomical observations with these instru-
ments, a complete observation will be understood to imply the mean of
a i)air of ol)servations, one with face right, the other with face left, taken
continuously without any considera1)le pause between them, the entire
operation being considered as one observation.
24(5 HINTS TD TRAVELLERS.
Dcter/uinatioiis of Time, Azhauth, jAditmle and LoiKjUade, with a Suhti-nse
Theodolite.
Tlie subtense theodolite may be employed either as a transit instrument,
or as an altazimuth instrument ; it is adajjted for all astronomical
observations, excc])ting those of "luaar distances," Avhich can only be
performed by a sextant or a reflecting circle, and occultations, which
require larger telescopes.
Thus a description of each of the varioiis kinds of observations which
can be made with transit and altazimuth insti-uments, with full details
of the methods to be employed in the corresponding reductions, would
fill a Yolume, and be much more than is required for a book which merely
purports to give hints to travellers. Those who wish to learn full
particulars of each of the several methods of observation, and of the
reductions, cannot do better than study Chauvenet's 'Sj^herical and
Practical Astronomy,' which is one of the most valuable works on the
subject in the English language : it gives ample instructions for observa-
tions of all kinds, the rudest and most hurried, as well as the most
relincd and elaborate, and it supplies corresponding formulae — approxi-
mate as well as rigorous — for the reduction of the observati(jns.
As these Hints are merely intended to indicate the simplest and most
expeditious methods by which a traveller who is able to carry a suitable
altazimuth instrument about with him, can take the astronomical
observations which are essentially necessary for his geographical ex] dera-
tions, they will be restricted to determinations of time, latitude and
longitude by the measurement of zenith distances, and of azimuths by
horizontal angles; formula)— some approximate but all sufficiently
rigorous for the purpose, and adapted mostly from Chauvenet — will also
be given, for the reduction of the observations.
Latitude Observations, the time being unknown. — The instrument being
duly levelled and brought approximately into the meridian, set the
telescope on any star — or on the siin — when approaching culmination,
and follow it until the maximum altitude is reached ; take the zenith-
distance reading on the vertical circle, change face quickly, and make a
second observation ; the mean of the two will be a " complete observation "
of zenith distance. Two or tiireo pairs of tibservations may be taken to
THEODOLITE OBSERVATIONS. 247
circumpolai- stars, as their zenith distances will not alter sensibly during
an interval of a quarter to half an hour ; for other stars the observations
should be restricted to one pair, and stars should not be observed when
within 25^ of the zenith, A single pair of observations with the 6-incli
transit theodolite should give a determination within 20" of the truth ;
greater accuracy may be obtained by observing additional stars, more
particularly when the stars are selected so as to form pairs of nearly
equal distance from the zenith, north and south.
Latitude Observations, the time being knoivn. — (l.) Observe the zenith
distance of the Pole-star in any position, and reduce to the meridian by
the tables in the ' Nautical Almanac'
[2.) Take circum-meridian observations of the zenith distance of any
star, alternately face right and face left, and note the time of each obser-
vation; compute the reduction of the zenith distance at the time of
observation to the distance on the meridian, and take the mean of the
reduced results as the determination of the meridional zenith distance.
Three or four pairs of observations may generally be made in succession
to the same star ; but the nearer the star is to the zenith the more
accurately should the times be known — it is not desirable, therefore, to
observe stars within 10° of the zenith. Here, too, pairs of north and
south stars of nearly equal zenith distance will give the best results.
Time. — Take pairs of observations of the zenith distance of a star,
noting the chronometer time of each, and adopt the mean of the times as
the time corresponding to the mean zenith distance, with which, the
latitude of the place, and the star's declination, the star's hour angle
must be computed by either of the well-known formulae : thus the local
time and the chronometer error will be determined. For these obser-
vations stars are most favourably situated which are easterly or westerly,
and not very near either to the horizon or to the meridian ; and greatest
accuracy is obtained when two stars are observed at nearly the same
altitude, one to the east, the other to the west. With a pair of observa-
tions the chronometer error should be determined within 1 second when
a 6-inch transit theodolite is used.
Longitude. — Take pairs of observations of zenith distance, face right
and face left, on a star, for the determination of local time and clirono-
meter error; then take other pairs of observations of zenith distance on
the moon; in each instance adopt the mean of the chronometer times as
248 HINTS TO TKAVELLEKS.
tlic time of the "complete obscrviitioii" of zenith distance. Eotli moon
and stai- sliould be as nearly easterly or westerly as possible, and always
materially nearer the prime vertical than the meridian; and they should
be snlliciently aV)0ve the horizon to prevent the o1>servations being
sensibly affected by errors of refraction. The operations should com-
mence and close with star observations, for time and chronometer rate.
The effect of instrumental errors will probably be sensibly reduced when
the star and the moon are (m the same side of the meridian, and nearly
at the same zenith distance. If time permits, ol)servations should be
taken both east and west of the meridian; and both before and after full
moon.
Tlie best time for observing tlu; moon is when the direction of the
resultant of her motion in right ascension and declination is pointing
towards the zenith of the observer.
The sidereal time when this occurs may be readily found, graj^hically,
by drawing on a chart of the heavens a tangent to the moon's orbit, at
some point near its mean position on any given day, and producing the
tangent to cut the declination circle passing through the observer's
zenith ; then the hour circle passing through the point of intersection
gives the sidereal time of observation. It will ordinarily suffice to drop
a perpendicular from the point indicating the moon's position on the
ecliptic, and draw through that point a line at right angles with the
perpendicular to cut the declination circle. It will be found that the
most favourable time occurs when the moon 'is near the prime vertical,
and the least favourable when she is near the meridian. In north lati-
tudes the moon is most favourably situated when west of the meridian if
her motion in declination is from south to north, and when east of the
meridian if the motion in declination is from north to south.
A few observations taken daily on several days are preferable to several
observations on a single day.
Azimuth, time and latitude heirtg uitl-nown. — Observe the angles between
a referring mark* and a star, when the star is at the same altitude east
"■ A good referring mark mey be made of a cross witli a hole of | to ^ an inch
in diameter in the centre, to wliich observations can be taken by day and by
night, being rendered visible at night by a bull's-eye lantern placed behind tlie
hole and directed to the observer. TJ'.e stem of the cross should be vertical, and
THEODOLITE OBSERVATIONS. 249
and west of the meridian ; several pairs of observations may be taken at
consecutive altitudes, half with face right and half with face left. Or the
angles may be measured between a referring mark and a circumpolar
star at the times of its maximum elongations east and west. The mean
of the two angles at opposite positions gives the angle between the star
and the meridian, and thence the azimuth of the referring mark, without
any calculations whatever. In the first case, however, an interval of
several hours must be allowed to elajjse between the observations east
and west ; and as twelve hours must necessarily elapse between the
opposite elongations of a circumpolar star, few stars will ordinarily be
visible at both elongations.
It may therefore be desirable to adopt a third and more expeditious
method, as follows: — Measure the angles between the referring mark and
two circumpolar stars at their respective elongations, selecting stars which
are nearly in opposition or nearly in conjunction, and will attain their
maximum elongations at nearly the same time, that the observations may
bo completed quickly ; then, with the observed value of the angle between
the stars, and the given declinations of the stars, the azimuths of Ijoth
may be readily computed, as shown at page 235.
Azimuths, latitude being knowv. —Ohsevve the angle between the re-
ferring mark and a circumpolar star at maximum elongation, and compute
tlie azimuth of the star. To stars near the pole two or three pairs of
observations, face left and face right, may be taken before the star moves
sensibly from the position of maximum elongation.
Azitnuth, latitude and time being known. — Any star may be observed in
any position, but the best results will be obtained when a circumpolar
star is observed at a short distance from the elongation ; -the angle between
the position of the star at the observation and at the elongation may be
computed by the last formula at page 255.
Azimuth, latitude and star's altitude being linown. — Observe the angle
between the referring mark and an east or west star, and measure the
vertical angle of the star simultaneously by observing the star at the
driven firmly iuto the ground. The distance from the station of observation
should be at least lialf a mile, and the station should be marked by a pin driven
into the gronnd, over which the theodolite must be carefully centered whenever
set up for horizontal obicrvatiou.s.
250 HINTS TO TRAVELLERS.
intersection of tlie liorizontal and vertical wires of the tlieodolite ; change
face and repeat the measures of the horizontal and vertical angles, taking
the mean of each as a "complete observation." The star should not l)e
at a high altitude; it should be situated near the prime vertical, and
rather on the side towards the apparent pole than on the opposite side.
This method is extensively practised in the Indian Surveys for the
determination of verificatory azimuths for revenue surveys, for which it
has been found more convenient than any other method. The observa-
tions are usually taken between sunset and dark, when there is sufficient
light to dispense with lamps for illuminating the wires of the telescojie
or indicating the referring mark ; a lamp to illuminate the graduations
of the circles is, however, generally necessary.
General llemarhs. — The observed zenith distances should always be
corrected for refraction; barometer and thermometer readings should,
therefore, be taken during the observations, for the better determination
of the I'efraction. When no barometer is at hand, the height of the
station of observation should be given, as deduced by the boiling point
or otherwise, or even approximately estimated. It may be well to
remember, in determining latitude by observing pairs of north find south
stars of the same zenith distance, that the means are uninfluenced by
refraction, and therefore corrections for refraction may be dispensed with.
Formuhti and Examples.
Latitude hi/ Circum-meridian Observations of a Star.
Let (f) be the true latitude, C the true zenith distance on the meridian,
Co the observed zenith distance corrected for refraction, S the declination
of the star,* ^„ an approximate value of (p, = 8 ± Cu, t the hour angle of
the star.
Put A = ^s to cosS ^^^ ,,^ ^ _^ ^.^, ^^^
sm Co sin I
Then C=L- ^ "*> and <p = 8 ± C
* When the suu is observed, the ilfclination corresponding to the mean of the
times of obseivutiou should be used.
THEODOLITE OBSERVATIONS.
251
The values of m are given in table X. (p. 280).
Alternative forms of m, ] m = cosec i" versin t.
adapted for various} = "00055!!^, when < is given in seconds of time,
logarithmic tables. ■' =2t- nearly, „ „ minutes „
Supposing /( observations to be taken, then, since A is constant,
^ _ /• . mj + ^2 + • • • • + '»n
^ — io ~ -^^ •
^a;amjj?c.— CiRCUji-MEMDiAK Observations for Latitude to ;3 Urs.h3 Minouis
North of the Zenith.
Left
Right
Left
Rigiit
Left
Kigi.t
Circle Readings
Mean Zenitli
Disti\nces
of Pairs of
Observations.
Alt.
Z. i).
Alt.
z."d.
Alt.
Z."l).
54 10 2ot
3; 4; J5/|
j; 45 ou
54 'o 50^1
54 II o)
3; 45 15/
35 45 io\
54 10 40/
54 10 io\
a 45 50/
IMean . .
Refraction . .
^0 =
— A«i =
ii 47
35 47
35 47
35 47
35 47
Cinonometer.
{''
40
35
47
4-
2;
42
35
48
5
2f
If. s.
45 47
47 I
48 55
51 JO
54 37
56 22
57 4?
53 48
o 18
2 10
in Minutes
of Time.
7-2
6-0
4-1
1-5
1-6
34
5-6
7-3
9-2
Data.
^H of Star ..
Ohron. Krror
Cliron. Time
of Transit
51 14
1 46
i = 35 47 44
Mean . . ji- ;
log cos 4>Q ■ •
los COS 5 . .
log cosec ^"0
log A
log 62-6 ..
^ =
31-3 X 2 = 62-6.
38^58' 53" X.
log Am
y^-
53
74
35
46 37
48 5
38
58 32
.. 9-8906
.. 9-4192
.. 0-2J28
.. 9-5426
.. l-7'/>5
.. 1-3391
For the above formula ( should ba less than 20 minutes, and ^ greater than 10°.
* Tlie circle; rciiding's will be alternately ;iltiimles and zt-iiith distances ± tjio
index cn-or of tlic in.stiumtnt, which error is eliiuiiiated in the iii(;an of a pair of
C)l)sorvatiou3
252 HINTS TO TRAVELLERS.
Longitude by Lunar Zenith Distances.
The local time and the chronometer error having been fletermined from
the star observations.
Let fo = the observed zenith distance of the moon's limb.
e = the local sidereal time of the observation of C„.
Li = an assumed value of the longitude.
A L, = the required correction of Lj.
L = the true longitude = Li + A Lp
(f) = the latitude.
Find the Greenwich time corresponding to 8 and Lp for wliieh take
S = the moon's declination. \ ^^.^^^ ^j^^
TT = the moon's equatorial horizontal parallax. / , Nont Aim '
S = the moon's geocentric semi-diameter. J
Let Si be the moon's apparent semi-diameter, and tt, tlie corrected
parallax,
then Sj = S + A S, and ttj = tt + Aw;
and the values of A S and A tt maj' be interpolated from the following
tables which are abridged from Chauvenet.
Also put Si = S + e^ TTi sin </> cos 6, in which log e- = 7"8244; and let
r be the refraction for the apparent zen. dis. ((, ;
and let (, = Co + '' ± ^'u
and Ci = f 2 — TTi sin d ;
then the hour angle, t, is found from the equatioii
sin^ 1 1 = ^"' ' ^^' + ^^ - ^'^^ ^"' ^ t^^' - ^"^ -^'^\
cos (p cos 6,
after which the moon's right ascension, .Tl, is fonnd by the formula
Ai = e - t.
THEODOLITE OBSERVATIONS.
253
N'alues of A S, always + .
Value of A tt, always + .
Apparent
Horizontal Semi-diameter.
Lati-
tude.
Equatorial Parallax.
Zen. Dis.
of Mix.n.
. > "
; // 1 )'
, „ ! , „
• > n
, ■ >
14 JO
15 15 JO
16 16 JO
17
5? 57 6t
o
„
„
„
M <r
„
II 11
1/
o
ir7
14-6
1,-6
ib-l 17-7
i8-8
O'O O'O
o;o
lo
ir?
'44
15-4
16-4 17-5
i8-6
10
o-j o-j
04
20
12-9
ir8
14-7
15-7
i6-7
17-7
20
1-2 1 I-J
i'4
JO
11-8
12-7
iJj
14-4
>5-4
16 -J
io
2-7 ^ 2-9
J-i
4^
IO-5
11-2
I2-0
12-8
n-6
14-4
40
44 1 4*7
51
50
8-3
V4 lo-i
107 11-4
I2-I
50 6-2 6-7 ' 7-2
60
6-9
-•J
7-9
8-4 ' 89
9-5
60 80 8-6 9-2
70
4-7
51
5-4
5-8 6-1
6-5
70 1 9'4 lo-i io'8
8o
2-4
2-6
2-8
j-o j-2
J-4
80 lo'j ii-i II-9
'P
0- I
o-I
o-i o-i 0-2
0-2
90 i:;-6 ii'4 12-2
The Greenwich mean time corresponding to the moons M must be found
from the ' Xautical Almanac ' ; with this, and the local mean time a value
of the longitude is determined, wiiich, however, is approximate only, as t,
is computed with an approximate value of 8 depending on the assumed
longitude. Put L2 for the approximate value of the longitude which is
thus determined, and
. „ ., . J, ^ . -L c I- [ '^^ the Greenwich mean
put jS = the increase of ni a unit of time ,. „ ,, , ,.
^ ^ K time of the observation
-'' t )) y Qf ^1^,^ moon ;
and X
alsolet«=JLji^^-ilE_M;
1 5 A ( Sin t tan t )
then A L, = -' ~ ', and L = L, -F A L,.
I + a ^ '
These forraulse are demonstrated in Chauvenet, vol. i. pages 383 to 385;
and M'hen several observations have to be I'educed, they entail less labour
of comi^utation than any other formula.
254 HINTS 'j'o ti!Avi;m-ki;s.
Kmiiijih: — III latitiulc r/) = 38" 58' 53" N. and iis.suiii(;<l loiicjitiulc !>, =
5 li. 6111. west of (Jrcemviclijon IMay 2iid, 1849, the moon liciiig cast of the
meridian, the zenith distance of the moon's upper limb was oKservcd to
I10 57^^ 47' 28"5", when the local mean time was 5 h. 33 m. 2i"6 s., and tlie
local sidereal time 6 = 8 h. 16 m. 14*61 s.
Approximate Greenwich mean time, "^ ' "
10 h. 39 m. 2 1-6 s. Bar. 30-45 in.j („ =57 47 28-5
for which we find from the Att. Therm. 63'' F.| r = + 1 30*9
'N.A.'S = +3^47' 47-6" Ext. „ 65'^F.)Si=+ 15 24-5
S = 15 i6"4
TT = 56 3-1 ^2 = 58 4 23-9
- TTj sni Ci = - 47 38-1
and from the tables on page wo iiutl
A S = +8-1 Ci = 57 16 45-8
A TT = + 4'4
e"7risin(/) | ' ^ " S
cos 5 (- + '^'
With these values cf <%, f„ and (/> we liud—
11. M. S.
/ = - 3 19 53-64;
but e = 8 16 1 4 • 6 1 ;
whence the computed M= n 36 8-25.
The corresponding Greenwich mean time for this value ) "■ ^'•
ofthe^is .: r° ^'^ -^^■"
The local mean time is .. •• •■ •• .. 5 33 2i'6
3 48 i-7
Whence the approx. long L.J is 5 627'i
• M. S.
"• "■ >"■ [increase of yR, in i = 2-014 = ^•
For the GrceuAvich mean time 10 39 48-7) ^ " „
I „ ,, = lO'OI = p.
Whence n — — o'33i7 : and since L.^ — Lj = 4- 27"i s.,
b. II. M. s.
A Li = 40-6, and L = 5 6 4o-6.
THEODOLITE OBSERVATIONS. 255
Fvi' in alls for tlic rediKtion of Azimuth Observaiivits.
( 1 ) AVhen a star is observed at au elongation.
jjct A l>o the azimuth, S the declination, cf) the latitude.
mi • A cos 8
Then sui A =
cos cf)
(2) When a star is observed at a short distance from the elongation.
Let t be the hour angle at the time of elongation,
then cos t = ,' — i.
tan S
Let d the the difference between the hour angles at the times of elonga-
tion and of observation, and d A the corresponding difference of azimuth,
then tan d A = — 2 sin-— sec (j) cot S cosec t ;
2
whence ii d t in expressed in minutes of time, and k is a constant,
log K being = "29303 + log sec + log cot S + log cosec /,
d A" = -K {d ty.
(3) When two stars are observed at their elongations.
Let their azimuths be Aj aud A^, and their declinations t\ and 8.^,
then sin A, = ' ' sin A.,.
cos 8.^
The value of A, + A^ or of A, — A^ is given by the observations, Aj +
A.J if the stars are at opposite elongations, Aj — A^ if they are at the same
elongation. Suppose that we have
Ai ± Ao = rn
then cot A, = cot »? ± '- cosec m,
cos §1
or cot A, ■= cot m ± ^—J- cosec m.
cos o.
256 HINTS TO TRAVELLERS.
Exri.ANATlDN OF THE TABLES.
Table I. contains the sun's declination, to tlie nearest minute, for the
years 1893-94-1)5 and '96 ; the declinations for the years 1897-98-99 and
1900, and are almost equally correct.
Table II. contains the equation of time fur 1893-94-95 and '90 to the
nearest second, and will serve very well for common purposes for the
4ih or 8th years after. The error will be greatest from the latter end
of May to the middle of July, to 2 sees, or 8 sees, in a period of four
years. The words "add" or "sub." indicate the manner in Avhich the
equation is to be applied to cq^pureut time to convert it into mean time.
Table III. contains the sun's mean right asccnsicjn. The months are
given at the top of the table, the days in the side column. It will be
found useful for ascertaining the approximate time of an object's meridian
l)assage, but where accuracy is necessary recourse must be had to the
' Nautical Almanac'
To find the app>roxim'tfe time of a star passing the meridian, subtract
the sun's right ascension from the star's right ascension (increasing the
star's right ascension by 24 hours if it is less than the sun's right
ascension), and the remainder will be the approximate time of the star
passing the meridian.
Table IV. contains the mean places of 50 stars of the first and second
magnitudes for the 1st of January, 1894, with their annual variation in
right ascension and declination.
Tables V. and VI. — Table V. contains the approximate times of the
meridian passages of 50 of the principal stars for the 1st of the month.
To find the time of passage on any other day, subtract the portion of time
corresponding to the day of the month in Table VI. from the time in
Table V. As the times given in these tables ai'e apparent, they must be
converted into mcuu time by applying the equation of time as dii'ccted
in Table II. should the mean time of meridian passage be required.
The result arrived at by the use of these tables is only approximate, but
will seldom be as much as 2m. in error.
N.B. — The altitude of any star when passing the meridian may be found
by adding together the comjilement of the latitude of the place of observa-
tion and the declination of the star, when they are of the same name.
EXPLANATION OF THE TABLES. 257
or takiug their difference when of contrary names ; the altitude to be
reckoned from the south point of the horizon when the hxtitude is north,
and the contrary when south ; but when the sum exceeds 90^ it is to be
taken from 180"^, and the altitude is to be reckoned from the north in
north latitude, and the south in south latitude. When using the
artificial horizon, the altitude to which the index of the sextant is to be
set must, of course, be double the altitude found by this method.
Table YII. contains the refraction for the barometer at 30 inches, and
Fahrenheit's thermometer at 50". The two small tables at the side
contain corrections when the barometer differs from 30 inches or the
tliermometer from 50".
Table YIII. exhibits half the time that a celestial body continues above
the horizon when the latitude and declination are the same name ; or
below it when they are contrary names, and affords the means for com-
puting the rising and setting of the sun, moon and stars, and the length
of the night or day.
To find the time of the ;:u)i/s rising or setting, enter Tal)le VIII. with
tlie latitude and declination, and the tabular value will show the apparent
time of the sun's setting when the latitude and declination are the same
name, or of its rising when the latitude and declination are of contrary
names, and this, subtracted from 12 hours, will give the api^arent time
of the sun's rising in the former case, and of its setting in the latter.
Double the time of rising will give the length of the night.
Double the time of setting will give the length of the day.
Eaample. — Eequired the (ap^Darent) time of the sun's rising and setting,
and the lengtli of the day and night in lat. 46' n., and the declination
18" N.
Tabular value answering to lat. 46 and decl. 18" is 7 h. 19 m. Hence
in lat. 46^ N., decl. 18" n., time of sunset is 7 h. 19 m., and that of sunrise
12 h. — 7 h. 19 m. = 4 h. 41 m.
The same is true for lat. 46° s., dec). 18° s.
Conversely, both for lat. 46° n., decl. 18° s., and for lat. 46° s., decl.
18'" N., the time of sunrise is 7 h. 19 m., and that of sunset is 4 li. 41 m.
In the first pair of cases the length of the day is 7h. 19 m. x 2 =
14 h. 38 m., and that of the night is 4 h. 41 m. x 2 = 9 h. 22 m. ; and in
the second pair, conversely, the length of the night is 14 h. 3S m., and that
of the day 9h. 22 m.
T
258 HINTS TO TKAVELLER.-^.
To Jhid the time of a dar's riainfj and scUivfj, subtract tlie snii's right
ascension, Table III., from the star's right ascension, Table IV. (increasing
the star's right ascension by 24 hours if it is less than the sun's right
ascension), and the remainder will be the apj^roximate time of the star's
passing the meridian ; then the latitude and declination found in this table
will give the time the star takes in ascending from the horizon to the
meridian, and descending from the meridian to the horizon, when the
latitude and declination are the same names ; therefore, if these hours and
minutes be subtracted from the time of its passage over the meridian, the
remainder will be the apparent time of its rising; and, if added, the sum
will be the time of its setting.
When the latitude and declination are of contrary names, the time
found in the table will be the half of the continuance of the star below
the horizon ; consequently it is to be subtracted from 12 hours to give
half the time of its continuance above the horizon.
Example. — At what time (apparent) does the slar fi Leon is rise and
set on May 30th in lat. 46° n. ?
II. M.
Star's E. A ir 43
Sun's E. A 427
Star's approximate meridian passage 7 16
Time in table answering to lat 46^ N. and stars j
declination 15° 15' N /
Ecmainder = time of star's rising 00 12
Sum = timc of star's setting 14 20 P.M.
or 2 20 A.M.
EXPLANATION OF THE TABLES. 259
Example. — At what time (apiDai'cut) does the star o 02>hiti''Ju rise aud
set on May 1 2th, iu lat. 30 s.?
ir. jr.
Star's E. A 17 29
Suu's E. A 3 15
Star's approximate meridian passage ' . . 1 4 1 4
Time answering in table to 30° s. lat., and star's i
declination 12'^ 39' n. = 6li, 30 m. which, snb- > 5 30
traded from 12, gives 5 h. 30 m J
Etmainder = time of star's rising 8 44
Sum = time of star's settiug 19 44P^-
or 7 44 -^-M.
Table IX., giving the distance of the horizon as seen over water from
different heights above it, will be found very iiseful both in checking
exaggerated estimates of the width of lakes Avhose 'opposite shores are
invisible, and also as a rude means of judging the distance of objects seen
across water.
Table X. gives the values of 2 sinMialf-hoiUMUigle ^ ^^^ -^ ^^^^^ -^^
sm i
finding the latitude by altitudes of the sun, or of stars when they are near
the meridian.
Table XI. gives the number of geographical miles, or minutes of the
equator, contained in a degree of longitude under each parallel of
latitude on the supposition of the earth's spheroidal shaj^e with a com-
pression of ^iz-
Table XII. is for converting statute into geographical miles.
Table XIII. is for converting geographical into statute miles.
Table XIV. contains a comi^arison of Fahrenheit, Eeaumur, and
Centigrade thermometer scales.
Table XV. contains a comparison of English and French barometer
scales to hundredths of an inch.
Table XVI. contains a comparison of metres and English feet.
Table XVII. contains a comparison of kilometres and English statute
miles.
T 2
200 HINTS TO TRAVKLLERS.
Tabic XVIII. contains a comparison of Russian vcrsts and English
statute miles.
Tal)le XIX. contains a comparison of kilogrammes and pounds,
avoirdujwis.
Tabic XX. contains foreign moneys, ■with equivalents in British
currency.
Table XX [. contains the difference of latitude and departure for the
course at each degree. It will also be found useful for the con-
version of one measure of length into another, thus: at GP, the dist.
and dep. correspond to statute and geographical miles; at 77"', dist. and
dep. correspond to English and Danish feet; at 68"^, dist. and dep.
correspond to Dutch and English feet ; at 66', dist. and dep. correspond
to French metres and English yards; at 70', dist. and dep. correspond
to toises and fathoms; at 25', dist. and dep. correspond to English feet and
arsheens ; at 35', dist. and dep. correspond to versts and geographical
miles; at G6', dist. and dep. corresi^ond to brazas and fathoms, or to
varas and yards. These tables can also be used in solving, approximately,
cases of right-angled triangles, as also in verifying the results of questions
of the kind when obtained by logarithms.
Table XXII. contains natural sines, cosines, tangents, cotangents,
secants, and cosecants for each degree.
Table XXIII. is used to facilitate finding the longitude by moon
culminating stars; for the manner in which it is used, see p. 233.
Table XXIV. This table contains the angles subtended by a 10 ft.
rod, at distances from 50 to 1500 feet. The angles are given for every
foot from 50 to 200 feet, for every two feet from 200 to 402 feet, and for
every yard from 402 to 1500 feet. To use the table, search column for
the angle measured, and opposite to this will be found the distance in feet.
In that part of the table, where the distances are only given for every
second or third foot, intermediate distances can be found by interpolation.
Table XXV. contains useful constants.
Tables XXVI. and XXVII. contain the tines occupied in tlie trans-
mission of letters and parcels by post from London to certain ]->laces
abroad.
TABLES.
2G1
Table I. — Declination of the Sun for the Years 1893 and 1807 at Mean Noon
AT Greenwich.
)ay.
Jan.
Feb.
March.
April.
May.
June.
July.
Aug.
Seiit.
Oct.
Nov.
Dec.
/
/
/
1
I
1
/
1
;
/
/
/
I
22 53 s.
16 57 s.
7 7.JS.
4 44 J^'
15 I4>-.
22 8n.
23 6n.
17 55N.
8 7J'-
3 23 s.
14 36 s.
21 54...
2
22 5J
16 40
7
5 8
15 32
22 16
23 I
17 39
7 45
3 46
14 55
22 i
I
22 4V
16 22
6 J7
5 30
15 49
22 23
22 56
17 24
7 23
4 9
15 14
22 U ,
4
22 40
16 4
6 14
5 53
16 7
22 30
22 51
17 8
7 I
4 32
15 a
22 19
5
22 ^4
i; 46
5 51
6 16
16 24
22 37
22 45
16 52
6 39
4 56
15 51
22 27
6
22 26
15 27
528
6 39
16 41
22 43
22 39
16 35
6 16
5 19
16 9
22 34
7
22 19
15 8
5 4
7 I
16 57
22 49
22 a
16 18
5 54
s 42
16 27
2241
8
22 II
14 49
4 41
7 24
17 14
22 54
22 26
16 I
5 31
6 5
16 44
22 47
9
22 2
14 30
4 17
7 4'''
17 30
22 59
22 19
15 44
5 8
6 28
17 I
22 53
lO
21 5J
14 It
^ 54
8 8
17 45
2J 4
22 12
15 26
446
6 50
17 18
22 59
1 1
21 44
n 51
3 30
8 30
18 I
23 8
22 4
15 9
4 23
7 IJ
17 35
2} i
12
21 J4
U Jl
3 7
8 52
i3 16
2J 12
21 55
14 51
4
736
17 51
23 8
I I
21 24
IJ II
243
9 14
18 31
23 15
21 47
14 n
i 37
758
18 7
2J 12
'4
21 IJ
12 50
219
9 36
18 4;
23 18
21 37
14 14
i 14
8 20
18 23
23 16
15
21 2
12 io
I 56
9 57
18 59
2} 21
21 28
IJ 55
2 51
8 43
i3 38
23 19
V>
20 50
12 9
I 32
10 18
19 13
23 23
21 l8
13 36
2 27
9 S
18 53
23 21
n
25 J 8
II 48
1 8
10 39
19 27
23 24
21 8
ij 17
2 4
9 27
19 8
23 23
i3
23 26
II 27
045
II
19 40
23 26
20 58
12 57
I 41
9 49
19 22
23 25
19
20 14
11 5 •
21 s.
II 21
19 53
23 27
20 47
12 38
I 18
10 10
19 36
23 26
23
20 I
10 44
3^'.
II 42
20 5
2? 27
20 35
12 18
54
10 n
19 50
23 27
21
19 4"
10 22
27
12 2
20 18
23 27
20 24
II 58
31
10 5J
20 3
23 27
22
19 ii
10
50
12 22
20 29
23 27
20 12
II 38
8x.
II 14
20 16
23 27
2!
19 19
9 i8
I 14
12 42
20 41
2? 26
20
II 18
16 s.
II 35
20 28
23 26
24
19 5
9 16
I J7
13 2
20 52
23 25
>9 47
10 57
39
II 56
20 40
23 25
25
18 50
8 5J
2 I
13 21
21 3
23 24
19 ^4
10 36
I 3
12 17
20 52
23 24
26
18 J5
8 31
2 25
13 4'
21 13
23 22
19 21
10 15
I 26
12 38
21 3
23 22
27
18 19
8 8
248
14
21 23
23 19
19 7
9 54
I 49
12 58
21 14
23 19
23
18 i
746
3 It
14 19
21 li
23 16
18 53
9 JJ
2 13
IJ 18
2t 25
23 16
29
17 47
3 35
'4 il
21 42
23 U
18 39
9 12
2 36
13 38
21 35
23 13
p
17 Ji
358
14 56
21 51
23 10
18 25
8 50
2 59
13 58
21 45
2J 9
;i
I- 14
4 21
22
18 10
8 29
14 17
23 4
202
HINTS TO TIIAVKLLHKS.
TaIU.I'; I. (riiHlhlitnl). — Dl.Cl.lNA TKiN iil' TIIK SlN I'lili TIIK YkAKS I Mil ANP IS'.t.S AT
j\Ikan Niidn at Gi;i;i;:;\vi(,'h.
Jun.
Feb.
o
,
t
I
22
59P.
17 IS.
2
22
54
16 44
i
22
48
16 26
4
22
42
if) 8
5
22
J5
15 50
6
22
28
15 32
7
22
21
15 IJ
8
22
15
M 54
9
22
4
'4 r,
10
21
55
14 15
II
21
46
n 56
12
21
}(>
IJ }(■>
1}
21
26
n 15
14
21
15
12 55
I)
21
5
12 35
i6
20
5J
12 14
17
20
41
I' 5i
i8
20
29
11 J2
>9
20
17
11 10
20
20
4
10 49
21
19 50
10 2-
22
19
37
10 5
2J
19
2j
9 43
24
19
8
9 21
25
18
54
8 59
26
18
39
8 37
27
18
2J
> 8 14
28
18
7
7 51
29
17
51
I ••
}0
17
35
il
17
18
1
April.
7 29^*
7 f'
6 4J
6 20
5 57
5 ii
5 10
4 47
4 23
4 o
3 36
i 12
2 49
2 25
2 I
I 38
1 14
o 50
o 27
03 s,
O 2IX.
44
1 8
1 32
1 55
2 19
2 42
3 6
3 29
3 52
4 16
4 39^'-
5 2
5 25
5 43
6 II
6 33
6 56
7 18
7 41
8 3
8 25
8 47
9 9
9 30
9 52
10 13
10 34
10 55
11 16
II 37
11 57
12 17
12 37
12 57
13 17
13 36
13 55
14 14
14 3i
14 51
May.
15 ION.
15 27
"5 45
16 3
16 20
16 37
16 53
17 10
17 26
17 42
17 57
18 li
18 27
18 42
18 56
19 10
19 24
19 37
19 50
20 2,
20 15
20 26
20 38
20 49
21 o
21 II
21 21
21 31
21 40
21 49
21 58
June. ; July. Aug. .Sept.
Oct.
Nov.
Dec.
22 6n.
22 14
22 21
22 28
22 35
22 41
22 47
22 53
22 57
23 3
23 7
23 II
23 14
23 17
23 20
23 22
23 24
23 26
23 27
23 27
23 27
23 27
23 26
23 25
23 24
23 22
23 20
23 17
23 14
23 10
23 l^i
2} 2
22 58
22 52
22 47
22 41
22 35
22 28
22 21
22 13
22 5
21 57
21 49
21 40
21 30
21 21
21 10
21 O
20 49
20 38
20 27
20 15
20 3
19 50
19 37
19 24
19 II
18 57
18 4J
18 28
18 13
17 58.N.
17 43
17 27
17 12
16 55
16 39
16 22
16 5
15 48
15 30
15 13
14 5;
14 37
14 18
13 59
1 13 40
13 21
13 2
12 43
12 23
12 3
II 45
II 22
II 2
10 41
10 20
I 9 59
1 9 38
'■ 9 17
3 55
8 34
8 12N.
7 50
7 28
7 (^
644
6 21
5 59
5 36
5 14
4 51
4 28
4 5
} 42
3 19 j
2 56 I
2 33
2 10
I 46
I 23
I o
o 36
o 13N.
O lOS.
34
° 57
1 21
I 44
2 54
3 17s-
3 41
4 4
4 27
4 53
5 13
5 }^>
5 59
6 22
6 45
7 8
7 30
7 53
8 15
8 37
8 59
9 21
9 45
10 ;
10 27
10 43
11 9
II 30
11 51
12 12
12 33
12 53
13 13
13 33
13 53
14 13
14 32s.
14 SI ,
15 10
15 23
15 47
16 5
16 22
16 4:^
16 57
17 14
17 31
17 47
18 3
18 19
18 34
' 18 49
19 4
19 i3
19 33
19 4<>
20 o
20 13
20 25
20 37
20 49
21 I
21 12
i 21 22
21 ?3
, 21 42
21 52s
22 I
22 9
22 18
22 25
22 33
22 39
22 4'j
22 52
22 57
23 2
23 7
23 II
23 15
23 18
23 21
i 13 23
23 25
23 26
23 27
23 27
23 27
23 27
23 26
23 24
23 22
23 20
23 17
23 13
23 10
23 5
TABLES.
263
Tablk I. {emit! lived).
-Declination of the Svn for the Yeai;s 1895 and 1S09 at
Mean Noon at GriKENWicii.
Day
Jan.
Feb.
March.
April.
May.
Juno.
July.
Aug.
Sept.
Oct.
Nov.
Dec.
1
/
(
/
TT
,
1
1
1
1
/
I
I
25 I S.
17 5S.
7 34 s-
4 ii^-
15 5X.
22
4x.
2} 8x.
18 2N.
8 17N.
3 I2S.
14 27 s.
21 50s.
2
22 55
16 48
7 II
4 56
15 23
22
12
23 3
17 47
7 55
3 35
14 46
21 59
I
22 50
16 }0
6 48
5 19
15 41
22
19
22 59
17 31
7 a
3 58
15 5
22 7
4
22 44
16 ij
625
5 42
15 59
22
27
22 54
17 15
7 II
421
15 24
22 16
5
22 r,
15 54
6 2
6 5
16 16
22
ii
22 48
16 59
6 49
4 45
15 42
22 23
6
11 30
■ 5 36
5 J9
6 28
16 a
22
40
22 42
16 43
627
5 8
16
22 31
7
22 22
15 17
5 16
6 50
16 49
22
46
22 36
16 26
6 4
5 31
16 18
22 38
8
22 15
14 59
4 52
7 n
17 6
22
51
22 30
16 9
542
5 54
16 36
22 44
9
22 6
14 39
4 29
7 35
17 22
22
57
22 23
15 52
5 19
6 17
16 Si
22 50
10
21 57
14 20
4 5
7 58
17 38
23
I
22 15
15 35
4 56
6 39
17 10
22 56
II
21 43
14
i 42
8 20
17 53
23
6
22 7
15 17
4 34
7 2
17 27
23 I
12
21 39
ij 41
i 18
8 42
18 9
23
10
21 59
14 59
4 II
7 25
17 43
23 6
U
21 29
13 20
2 55
9 i
18 24
23
13
2^ 50
14 41
348
7 47
17 59
2J 10
14
21 l3
13
2 31
9 25
18 33
23
17
21 42
14 23
3 25
8 10
18 15
23 14
15
21 7
12 40
2 7
9 47
13 53
23
19
21 a
14 4
3 2
832
18 31
23 17
i5
20 56
12 19
I 44
10 8
19 7
23
22
21 23
13 45
2 39
8 54
i3 46
23 20
17
20 44
II 58
I 20
10 29,
19 20
23
24
21 13
13 26
2 i;
9 16
19 I
23 22
i8
20 J2
II 37
56
10 50
19 34
23
^5
21 3
13 7
I 52
9 33
19 15
23 24
19
20 20
II 16
32
II II
19 47
23
26
20 52
12 47
I 29
10
19 29
23 26
20
20 7
10 54
gs.
II 32
19 59
2J
27
20 41
12 28
I 5
10 22
19 43
23 27
21
19 54
10 32
15N.
II 52
20 12
23
27
20 29
12 8
42
10 43
19 56
23 27
22
19 40
10 II
39
12 12
20 24
23
27
20 18
II 48
19N.
II 4
20 9
23 27
2j'
19 26
9 49
I 2
12 32
20 i$
23
27
20 6
II 27
5.?.
II 25
20 22
23 27
24
19 12
9 27
I 26
12 52
20 47
23
26
19 53
II 7
28
II 46
20 34
23 26
25
18 57
9 4
I 50
13 12
20 58
23
24
19 40
10 46
52
12 7
20 46
23 25
26
18 42
8 42
2 13
ij 31
21 8
23
23
19 27
10 2;
I 15
12 28
20 58
23 23
27
18 27
8 19
2 37
iJ 51
21 18
23
20
19 14
10 4
I 38
12 48
21 9
23 20
28
18 II
7 57
i
14 10
21 28
23
18
19
9 43
2 2
13 8
21 20
23 18
29
17 55
..
i 24
14 28
21 38
23
15
18 46
9 22
2 25
13 28
21 30
23 14
30
17 ^9
..
I 47
14 47
21 47
23
II
18 32
9 I
2 43
13 48
21 40
23 II
il
17 22
••
4 10
••
21 56
•
18 17
8 39
14 8
••
23 6
2G4
HINTS TO TRAYELLEKS.
Tauli: I. (rnnh'intril). — Dkcmnation op the Sun for the Yeai.-s 1800 and 1000 at
Mean Noon at GiiEENwrcii.
Day.
__
Jan.
I'd).
March.
April.
May.
.June.
July.
Aug.
Sept.
Oct.
Nov.
Dcr.
/
>
/
/
/
;
/
,
/
1
/
/
I
1} IS.
17 9 s.
7 17s.
4 5IN.
15 i9>;.
22 lOX.
23 4>''-
17 5IX.
8 IX.
3 29 s.
14 42.'.
21 57 s.
2
22 57
16 52
654
5 14
15 31
22 18
23
17 35
7 J9
3 5J
15 I
22 5
}
22 51
I*) i,-
631
5 31
15 54
22 25
22 55
17 19
7 17
416
15 19
22 14
4
22 45
16 17
6 8
6
16 12
22 31
22 50
17 3
655
4 J9
15 38
22 22
5
22 39
15 59
5 44
6 23
16 29
22 38
22 44
16 47
6 32
5 2
15 56
22 79
6
22 32
15 41
5 21
6 45
16 45
22 44
22 38
16 30
6 10
5 25
16 14
22 36
•7
22 24
15 22
5 5«
7 8
17 2
22 50
22 31
16 14
5 47
548
16 32
28 4!
8
22 17
"5 }
4 M
7 30
17 18
22 55
22 24
IJ 56
5 25
6 II
16 49
22 49
9
22 8
14 44
4 II
7 52
17 34
23
22 17
15 39
5 2
6 J4
17 6
22 55
10
22
14 25
i 47
8 14
17 50
23 5
22 9
15 21
4 J9
657
17 23
23 c
II
21 50
14 5
} 24
8 36
18 5
23 9
22 I
15 4
4 16
7 19
17 J9
23 5
12
21 41
u 4;
3
8 58
18 20
23 13
21 5J
14 45
3 5J
7 42
17 55
2J 9
li
21 }l
u 25
2 36
9 20
18 35
23 16
21 44
14 27
3 30
8 4
lo II
2J U
M
21 21
IJ 5
2 13
9 42
18 49
23 19
21 35
14 8
3 1
8 27
i3 27
23 16
15
21 10
12 44
I 49
10 3
19 3
23 21
21 25
13 50
2 44
8 49
18 42
23 19
i6
20 59
12 24
1 25
10 24
19 17
23 23
21 15
IJ 31
221
9 II
18 57
23 22
'7
20 47
12 J
I 2
10 45
19 30
23 25
21 5
IJ II
I 58
9 JJ
19 12
23 24
i8
20 35
II 42
38
n 6
19 44
23 26
20 54
12 52
I J4
9 55
19 26
23 25
'9
20 2J
II 21
14s.
II 27
19 56
23 27
20 43
12 32
I :i
10 16
19 40
23 26
20
20 10
10 59
ION.
II 47
20 9
23 27
20 32
12 12
48
10 38
19 SJ
23 27
21
19 57
10 36
3}
12 8
20 21
23 27
20 20
II 52
24
10 59
20 6
2J 27
22
19 4J
10 16
57
12 28
20 }}
23 27
20 8
II 32
IX.
II 20
20 19
23 27
2J
19 29
9 54
I 20
12 48
20 44
23 26
19 56
II 12
22 s.
,,41
20 ji
2J 26
24
19 15
9 J2
I 44
J3 7
20 55
23 25
19 4?
10 51
46
12 2
20 43
2J 25
25
19 I
9 10
2 8
13 27
21 6
23 23
19 {0
10 30
I 9
12 23
20 55
23 23
26
18 46
847
2 31
13 4(>
21 16
23 21
19 17
10 10
I JJ
12 4J
21 6
23 21
27
18 JO
8 25
2 55
14 5
21 26
23 18
19 3
948
I 56
IJ 4
21 17
23 18
28
18 .'5
8 2
3 18
14 24
21 35
23 15
18 49
9 27
2 19
ij 24
21 28
2J 15
29
17 59
7 }<)
3 41
14 45
21 45
23 12
1 1835
9 6
24;
IJ 4J
21 38
23 12
30
17 4?
..
4 5
15 I
' 21 5}
2; 8
18 21
8 44
J 6
14 J
21 47
2J 7
}l
17 26
4 28
22 2
18 6
8 2?
14 22
..
2? 3
TABLES.
265
Taulk II. — Equation of Time for the Yeau 1893 fok Aitakent]
Noon at Greenwich.
Day.
Jan.
Feb.
Marcb. April.
May.
June.
July.
Aug.
Sept.
Oct.
Nov.
Dec.
ni. F.
ni. s.
ni. s.
m. s.
m. s.
m. s.
m. s.
m. B.
m. s.
m. s. 1
ni. s.
m. s.
Add
Add
Add
Add
Sub.
Sub.
Add
Add
Sub.
Sub.
Sub.
Sub.
I
4 o
1} 52
12 26
3 48
3 4
2 23
3 37
6 4
14
10 28
16 20
10 40
2
4 28
li 59
12 -4
J 30 j 5 II 2 14
3 49
6
ii
10 47
16 21
10 17
3
4 56
14 5
12 I
J 12 i 18
2 4
360
5 55
53
II 6
16 21
9 53
4
5 25
14 II
II 47
2 55 h 2J
I 54
4 10
5 50
I 12
II 24
16 20
9 29
5
5 50
14 15
II 34
2 37
^ ^9 , I 44
4 21
5 44
I J2
II 42
16 18
9 4
6
6 16
14 19
II 19
2 20
i M 1 I jj
4 31
5 3a
I 52
II 59
16 15
8 38
7
6 42
1422
11 5
2 2
3 38 1 I 22
4 41
5 31
2 12
12 16
16 12
8 12
8
7 7
14 24
10 50
I 46
3 42 j I II
4 50
5 23
2 3}
12 33
16 7
7 45
9
7 J2
14:6
10 M
I 29
3 45 59
4 59
5 15
2 53
12 49
16 2
7 18
lo
7 56
14 26
10 19
I 12
3 47 47
5 8
5 6
3 14
13 5
15 56
6 51
II
8 20
14 26
10 5
56
3 49 J5
516
4 57
3 35
13 20
15 49
6 23
12
8 4J
14 26
9 47
41
3 50 23
5 23
4 47
356
13 35
15 41
5 55
li
9 5
14 24
9 }0
20
3 51 10
Add
5 31
4 36
4 17
13 49
15 32
5 26
'4
9 27
14 22
9 U
10
Sub.
3 51 3
538
4 25
4 38
14 2
15 23
458
15
9 48
14 19
8 56
5 1 -5 51 16
5 44
4 14
4 59
14 16
15 13
4 28
i6
10 9
14 15
8 J9
19 3 50 29
5 50
4 2
5 20
14 28
15 I
3 59
17
10 29
14 10
8 22 3i 3 4« 42
5 55
3 49
5 41
14 40
14 49
3 30
i8
10 48
H 5
8 4 47 j 3 46 1 55
6
3 36
6 2
14 52
14 37
i
19
II 6
1} 59
7 46
I ^ 43 I 8
6 4
3 23
624
15 2
14 23
2 30
20
n 24
IJ5J
■7 28
I 1} J 40 I I 21
6 7
3 8
6 45
15 13
14 9
2
21
II 41
I J 46
7 10
I 25 1 ^ ^^ I 34
6 10
2 54
7 6
15 22
13 54
I 31
22
II 57
1} jH
6 52
I 37 ^ ^'^ ! I 47
6 13
2 39
7 27
15 31
IJ 38
I I
2}
12 12
1} 29
6>4
I 49 3 27 J .(^
615
2 23
748
15 39
ij 21
31
24
12 26
1} 20
6 15
20 3 22 ; 2 12
6 16
2 7
8 9
15 47
13 J
I
Add
25
12 40
IJ 10
5 57 2 10 ; ^ "^ 2 25
6 17
I 51
8 29
15 54
12 4^
29
26
12 5J
1}
5 39
2 21 ^1° 2 37
6 17
I 34
8 50
16
12 26
58
27
U 5
12 50
5 20
2 JO ^ ■? 1 2 50
6 16
I 17
9 10
16 5
12 6
1 28
28
ij 16
12 }S
5 2
2 39 ' 5^ 1 3 3
6 15
59
9 30
16 20
II 46
I 57
29
li 26
4 4?
2 48 2 48 J ,^
6 U
41
9 5°
16 14
II 25
2 26
JO
1} j6
4 25 2 56 ^ 40 1 3 26
6 II
23
10 9
16 17
II 3
1 ^ ^'
31
«i 44
4 7' .. '^^^' ..
6 8
5
16 19
3 24
20G
iriNTB TO TRAVELLERS.
TahleJI. (rouluiiK'd). — Ei^uation of Time fou the Year 1801 fou Aitakknt
N00\ AT C4UEENWIC1I.
Day.
i[an.
Feb.
March. Aiiril. Jlay.
June.
July.
Aug
Sept.
Oct.
Nov.
1 'T.
m. E.
m. 8.
in. s.
m. s.
m. 8.
m. 8. m. s. m. s.
in. 8.
m. 8.
m. 8.
m. s.
Add
Add
Add
Add
Sub.
Sub. Add Add
Sub.
Sub.
Sub.
Sub.
I
i 5J
IJ 50
12 28
i 52
3 3
2 25 J 36
6 7
8
10 22
16 19
10 45
2
4 21
a 57
12 16
i H
3 10
2 16 3 47
6 3
27
10 41
16 19
10 22
3
4 49
14 4
12 J
J 16
3 16
2 6
3 58
5 59
46
10 59
16 19
9 58
4
5 i6
14 9
II 50
2 53
J 22
156
4 9
5 54
I 5
II i3
16 19
9 34
5
5 4J
14 14
II J7
2 41
3 28
145
420
548
X 25
II 36
16 17
9 9
6
6 lo
14 18
II 2J
2 24
J 32
I 34
4 30
5 42
I 45
II 5J
16 15
844
■7
6 }6
14 22
II 8
2 7
3 31
I 2J
4 40
5 35
2 5
iz 10
16 II
8 i3
8
7 I
14 24
10 5J
I 50
3 4°
I 12
450
5 27
2 26
12 27
16 7
7 51
9
7 26
14 26
10 j8
I JJ
3 4J
I
4 59
5 19
2 46
12 4J
16 2
7 25
lo
7 51
14 27
10 2J
I 17
J 46
49
5 7
5 10
3 7
12 59
15 57
6 58
II
8 15
14 27
10 7
I
3 4?
37
5 i'^
5 I
3 28
13 15
15 50
6 JO
12
8 38
14 26
9 51
45
J 49
24
5 2J
451
3 49
IJ JO
15 43
6 2
1}
9 I
14 25
9 J4
29
} 50
12
Add
5 Ji
441
4 10
13 44
15 34
5 34
14
15
9 2i
9 44
14 22
14 20
9 17
9
14
Sub.
I
3 51
3 50
I
IJ
5 37
5 +4
4 30
418
431
4 53
13 58
14 12
15 25
15 15
5 5
436
i6
10 4
14 16
8 4J
16
3 50
26
5 50
4 6
5 14
14 25
IS 4
4 7
n
10 24
14 II
8 26
JO
3 48
39
5 55
3 53
S 35
1437
14 J3
3 38
i8
10 4}
14 6
8 8
44
3 47
52
6
3 40
556
14 49
14 40
3 8
19
II 2
14
7 50
57
3 44
I 5
6 4
3 27
6 18
15
14 27
2 39
20
II 19
rJ54
in
I 10
3 41
I 18
6 7
3 13
6 39
15 10
14 IJ
2 9
21
II 36
li 47
7 14
I 2J
3 38
I 31
6 10
2 58
7
15 20
13 58
I 39
22
II 52
IJ J9
6 56
I 35
3 34
I 43
613
2 4J
7 21
15 29
13 42
I 9
2J
12 8
IJ JO
6 J7
I 47
3 29
I 56
615
2 28
7 42
15 37
IJ 25
39
24
25
12 22
12 j6
IJ 21
IJ 12
6 19
6
1 58
2 9
3 24
3 18
2 9
2 22
6 16
617
2 12
I 56
8 3
8 2J
15 45
15 52
13 8
12 49
9
Add
21
26
12 49
IJ 2
5 42
2 19
3 12
2 J5
6 17
I 39
8 4.
15 58
12 JO
051
27
IJ I
12 51
5 2J
2 29
3 5
2 47
6,7
I 22
9 4
16 3
12 II
I 21
28
1} 12
12 40
5 5
2 J8
2 58
3
6 16
I 5
9 24
16 8
II 50
150
29
IJ 2J
5 47 2 47
2 51
3 12
615
47
9 4J
16 12
II 29
220
30
IJ JJ
4 28 2 55
243
3 24
613
29
10 3
16 15
II 7
2 49
Ji
IJ 42
4 10
■■
2 J4
6 10
II
16 17
J 18
TABLES.
267
Table II. (conlhnicd).
-Equation op Tjme for the Year 1805 for Aitarent
Noon at GREENwrcii.
Day.
Jan. IVb. March.
April. M:iy. June. .July. Aug.
Sept.
Oct.
Nov.
Dec.
m. s. in. s.
m. s.
m. s.
m. 8.
m. s.
m s. m. 6.
111. S.
ni. s.
m. s.
111. s.
1
Add Add
Add
Add
Sub.
Sub.
Add
Add
sab.
Sub.
Sub.
Sub.
I
i 45 i; 48
12 }2
3 57
3
2 27
3 33
6 8
J
10 17
16 19
10 50
2
4 15 iJ 56
12 19
J 39
3 8
2 18
3 45
6 4
22
10 j6
16 20
10 28
i
4 43 14 2
12 7
3 21
3 14
2 8
3 56
6
42
10 55
16 20
10 4
4
5 10 14 8
II 54
3 3
J 20
I 58
4 7
5 55
' ^
II 14
16 20
9 40
5
5 il 14 I J
11 40
2 45
J 26
I 48
4 17
5 49
I 21
II J2
16 18
9 16
6
6 }
14 17
11 26
2 28
3 31
137
4 27
5 4J
I 41
II 50
16 16
8 50
7
6 30
14 21
II 12
2 II
3 36
127
4 37
536
2 I
12 7
16 IJ
8 25
8
655
14 2i
10 57
I 54
3 40
I 15
4 47
528
2 22
12 24
16 9
7 59
9
■7 20
14 25
10 42
I 37
3 43
I 4
456
5 20
2 42
12 40
16 4
7 32
lO
7 44
14 26
10 26
I 20
3 4*^
52
5 4
512
3 3
12 56
15 59
7 5
II
8 8
14 26
10 10
I 4
3 43
40
5 13
5 2
3 24
IJ 12
15 52
637
12
8 J2
14 26
9 54
48
3 50
23
521
4 53
3 45
13 27
15 45
6 9
u
8 54
14 24
9 38
J2
3 51
16
5 28
4 42
4 6
13 41
15 37
5 41
14
9 16
14 22
9 21
17
3 52
3
Add
5 35
4 32
4 27
13 55
15 23
5 12
15
9 38
14 19
9 4
2
Sub.
3 51
9
5 41
4 20
448
14 9
15 18
4 43
i6
9 58
14 16
8 46
IJ
3 51
22
5 47
4 9
5 9
14 22
15 7
4 14
IT
10 18
14 12
8 29
17
3 50
35
5 53
356
5 30
1434
14 55
3 44
i8
10 j8
14 7
8 II
041
348
48
553
3 43
5 51
14 46
14 AS
3 15
19
10 56
14 I
1 ■'^■^
055
3 45
I I
6 2
3 30
6 12
14 57
14 JO
2 45
20
II 14
liSS
' 736
I 8
3 42
I 14
6 6
3 16
6 3J
15 7
14 15
2 15
21
II }l
IJ 48
, 7 18
I 20
3 39
I 27
6 10
J 2
654
15 17
14 I
I 45
22
II 48
13 41
7 °
I 33
3 35
I 40
6 13
2 47
7 15
15 26
13 45
I 15
2}
12 4
13 }}
641
I 44
3 30
1 53
6 15
2 32
7 36
15 34
13 28
45
24
12 18
13 24
6 23
j
I 55
3 25
2 7
6 17
2 16
7 57
15 42
13 II
15
Add
25
12 }}
13 15
6 5
2 6
3 19
2 19
6 18
2
8 18
15 49
12 53
15
26
12 46
J3 5 5 47
2 16
J 13
2 32
6 i3
I 44
8 38
15 55
12 34
45
27
12 58
12 54 5 28
2 26
J 6
2 45
6 18
I 27
8 58
16 I
12 15
I M
28
13 10
12 43 5 10
236
2 59
2 57
6 17
I 10
9 18
16 6
II 55
I 44
29
IJ 21
..
4 52
2 44
2 52
3 9
6 16
52
9 38
16 II
11 34
2 13
3°
13 31
..
4 a
2 S3
2 44
3 21
6 14
34
9 58
16 14
II 13
242
JI
13 4°
4 15
, ••
2 35
••
6 II
16
16 17
••
3 II
268
HINTS TO TllAVELLEKS.
Taduc II. (amIhiintJ). — Equation of Time roit the Yeau 189G for Aivahent
Noon at Greenwich.
Day.
Jan.
Feb.
Marcli.
April.
May.
.June.
July. 1 Aug.
Scjit.
oa.
-Nov.
lAC.
ni. s.
m. s.
m. s.
m. s.
m. s.
m. s.
ni. s.
m. 8.
m. s.
m. 8.
m. s.
m. 8.
Add
Add
Add
Add
Sub.
Sub.
Add
Add
Sub.
Sub,
Sub.
Sub.
I
3 4°
13 47
12 23
3 44
3 6
2 20
3 41
6 4
19
10 33
16 20
10 34
2
4 8
13 54
12 n
3 26
3 12
2 II
3 52
5 59
38
10 52
i6 20
10 10
3
4 36
14 I
11 53
3 8
3 19
2 I
4 3
5 54
57
II 10
16 20
946
4
5 3
14 7
II 44
2 50
3 25
I 5«
4 14
5 49
I 17
II 28
16 19
9 21
5
5 }o
14 12
II 30
2 33
3 30
I 40
4 24
545
137
II 46
16 17
8 56
6
5 57
14 17
II 16
2 15
3 34
I 29
4 34
5 36
157
12 3
16 14
8 30
n
6 2i
14 20
II 1
I 58
3 38
I 18
4 44
5 29
2 17
12 20
16 10
8 4
8
649
14 23
10 46
I 42
3 42
I 7
4 53
5 22
2 37
12 36
16 5
7 38
9
7 14
14 25
10 31
I 25
3 45
55
5 2
5 13
258
12 52
16
7 10
lO
7 39
14 27
10 i;
I 9
3 47
43
5 II
5 4
3 19
13 8
15 53
6 4J
II
8 J
14 27
9 59
53
3 49
31
5 19
4 55
3 40
13 23
15 46
6 15
12
8 26
14 27
9 43
37
3 50
i3
5 26
4 45
4 I
1338
15 38
5 47
JJ
8 49
14 26
9 26
22
3 50
6
Add
5 33
4 34
4 22
.352
15 29
5 18
14
9 12
14 24
9 9
7
Sub.
3 50
7
5 4=
4 23
4 43
'4 5
15 20
4 50
15
9 34
14 22
8 52
8
3 49
20
5 46
4 JI
5 4
14 i3
15 9
4 20
i6
9 55
14 J 8
3 35
22
3 48 i 3i
5 52
3 59
5 25
14 31
14 58
3 51
n
10 15
14 14
8 18
36
3 47
46
5 57
3 46
546
14 43
14 46
3 22
l3
10 35
14 10
8 CO
50
3 44
59
6 I
3 33
6 8
14 54
14 33
2 52
19
10 5J
'4 4
7 42
I 3
3 41
I 12
6 5
3 19
6 29
15 5
14 19
2 22
20
II 12
13 53
7 24
I 15
3 38
I 25
6 9
3 5
6 50
15 15
14 5
I 53
21
II 29
13 52
7 6
I 28
3 34
I 38
6 12
2 50
7 II
15 24
13 49
I 23
22
II 45
13 44
6 43
I 40
3 30
I 50
6 14
2 35
7 32
15 33
13 33
53
^}
12 I
13 36
6 29
I 51 ' 3 25
2 3
6 15
2 19
7 53
15 41
1} 16
23
Add
24
12 16
13 27
6 n
2 2 3 20
2 l6
6 16
2 3
8 14
15 49
12 58
7
25
12 JO
ij l3
5 S3
2 13 3 14
2 29
617
' 47
8 34
15 55
12 40
37
26
12 44
13 8
5 34
2 23 3 8
2 41
617
1 30
855
16 I
12 21
I 6
27
12 56
12 58
5 15
2 32 3 I
2 53
6 16
1 12
9 15
16 6
12 I
I 36
28
13 8
12 47
4 57
2 42 2 54
3 5
615
5;
9 35
16 II
11 40
2 5
29
13 19
12 35
4 39
2 50 ' 2 46
3 18
6 13
37
9 54
16 14
11 19
2 35
}o
13 29
4 20
2 58 2 38
3 29
6 10
19
Sub.
10 14
16 17
10 56
3 4
JI
13 38
1 "* ^
.. 1 2 29
6 7
16 19
3 32
TABLES. 269
Table III. — Sun's Meax Eight Ascensiox.
Day.
Jan.
Feb.
March.
April.
May.
June.
July-
Aug.
Sept.
Oct.
Ifov.
Dec.
h. m.
h.
in.
h. m.
h. 111.
li m.
h. ni.
h. m.
h, m.
b. m.
h. m.
b. m.
b. m.
I
i8 46
20
58
22 48
42
2 33
4 J5
6 40
8 4;
10 41
12 29
14 25
16 29
2
18 50
21
02
2252
45
2 37
4 40
6 44
8 49
10 44
12 32
14 29
16 33
J
1854
21
06
22 56
49
2 40
4 44
6 48
8 52
10 48
12 36
14 33
16 37
4
18 59
21
10
22 59
53
2 44
448
6 52
8 56
10 52
12 40
14 31
16 42
5
19 i
21
14
2J 0;
56
2 48
4 52
6 56
9 00
10 55
12 4}
14 41
16 46
6
19 8
21
18
2J 07
I GO
2 52
456
7 00
9 04
ic 59
12 47
'4 45
16 51
7
19 12
21
22
2J 10
I 04
2 56
5 03
7 04
9 08
ir 02
12 51
14 49
16 55
8
19 16
21
26
2J 14
I 07
J oo
5 04
7 09
9 12
II 06
12 54
14 53
16 50
9
19 21
21
io
2? 18
I 11
? 04
5 08
7 13
9 15
11 10
12 58
14 57
17 04
10
19 25
21
i4
li 21
I 15
3 08
5 13
7 '7
9 19
II 13
13 02
15 01
17 08
II
19 29
21
;3
2} 25
I 18
3 II
5 '7
7 21
9 23
11 17
13 05
15 "5
17 IJ
12
19 J4
21
4i
2J 29
I 22
3 15
5 21
7 25
9 27
II 20
13 09
15 O)
17 17
i;
19 j8
21
46
2J 3J
I :6
J 19
5 25
7 29
9 31
II 24
13 13
15 I J
17 21
. 14
19 42
21
5°
2? j6
I 29
3 2;
5 29
7 33
9 34
II 28
I J 16
15 n
17 26
15
19 47
21
54
2J 40
I j}
3 27
5 33
7 37
9 38
II 31
13 20
15 2r
17 30
i6
19 51
21
58
2J 4J
I 37
3 31
5 37
741
942
II 35
13 24
15 25
17 35
17
19 5;
22
02
23 47
I 40
3 35
5 42
7 45
9 46
II 33
13 28
15 30
17 J9
l8
20 00
22
05
2J 51
I 44
3 39
5 4^
7 49
9 49
II 42
13 31
15 34
17 4J
19
20 04
22
09
2J54
I 48
i 4?
5 50
7 53
9 53
II 46
IJ 35
15 33
17 43
20
20 o3
22
I J
2j ;8
I 51
i 47
5 54
7 57
9 57
II 49
13 39
1542
17 52
21
20 12
22
17
02
I 55
J SI
5 58
8 01
10 oo
II 53
13 4J
15 46
17 57
22
20 17
22
21
05
I 59
3 55
6 02
8 05
10 04
II 56
13 46
15 50
18 01
2J
20 21
22
25
09
2 03
3 59
6 07
8 09
10 08
12 00
13 50
15 55
18 06
24
20 25
22
28
ij
2 o5
4 03
6 II
8 13
10 12
12 04
Ii 54
15 59
18 10
2>
20 29
22
J2
16
2 10
4 07
6 15
8 17
10 15
12 07
13 58
16 03
18 15
26
20 a
22
J6
20
2 14
4 II
6 19
8 21
10 19
12 II
14 02
16 07
18 19
27
20 ii
22
40
on
2 18
4 15
623
8 25
10 23
12 14
14 o5
16 12
18 23
28
20 42
22
4!
27
2 21
4 19
6 27
8 29
10 26
12 18
14 09
16 16
18 28
29
20 46
22
46
031
2 25
4 23
631
833
10 io
12 22
14 13
16 20
l3 32
JO
20 50
i4
2 29
4 27
6 36
8 37
10 33
12 25
14 17
16 25
18 37
JI
20 54
j8
"
4 ii
8 41
10 37
14 21
l3 41
270
HINTS TO TRAVEI.LKKS.
Tai!Le IV. — *Mean Places uf 50 of thk I'iiiN-cii'AL Fixed Stars kor
Januaiiy 1st, 18D1.
Name.
a Amiroiunlrt',
y Pegasi (Algcnib) .. .,
a Phociiicis
a Cassiopeiiu (vai.) .. ..
P Ceti
a Ursa3 Minoris (^Polaris)
a Eridani (Achenmr')
a Arletis ., ., .. ..
a Persei
a Tauri (^Aldebaran) ., ..
a Aurigre (Capella) .. .,
p Orionis (Rigel) .. ..
P Tauri
5 Orionis
a CjlumbiC
a Orionis (vav.1
a ATgCis {Canopus) .. ..
a Canis Majoiis (.SiVtus) . .
€ Cauis Majoi is
6 Canis Majoiis
a- Geminorum {Castor) . .
a Canis Minoris {Procyim)
p GcmhwTum (Pollux) ..
I Argils
a Hydra!
Mag. Kight Asc. lAnn. Var. Dcclluatton. Ann. Var.
2,i
li. m. s.
o 2 54'4;
o 7 46-57
o 21 2-5J
o J4 2</44
}Z 16-09
1 20 4-50
1 J3 45-95
2 I ii"7g
3 16 4J-I9
4 29 50-22
5 8 51-42
5 9 26-58
5 19 35-42
5 26 J5'i9
5 35 48"69
5 49 25-95
6 21 35-84
6 40 28-55
6 54 27'55
7 4 4-87
7 27 50-21
7 }} 45-12
1 33 49-77
9 14 15-22
9 22 22-68
+ J-09
3-08
2-97
i-oi
24-12
2-24
3-J7
4-26
i-44
4-43
2-38
3-79
3-06
2-18
J-25
I-3J
2-64
2-j6
2-44
3-84
3-14
3-68
1-61
2-95
4-28 }o 18-72
4-14 35 J8-77
-42 52 55-20
4-55 57 20-86
-i3 34 6-94
4-88 44 33-83
-57 Y^ Ji'Ji
4-22 57 39'46
+ 49 28 59-95
4- 16 17 44-97
4-45 53 22-82
— 8 19 23-07
4-23 31 2-89
— o 22 40-73
-34 " 50-75
-t-7 23 12-70
-52 38 16-30
-16 34 18-14
-28 49 41-32
-26 13 30-48
4-32 7 I4"38
4-5 2947-65
4-28 16 54-7;
-58 49 53-16
-8 II 57-73
4-1990
20-03
19 -55
19-79
19-81
18-84
18-33
17-18
13-07
7-50
4-ot
4-39
334
2-91
2-o3
0-95
-1-89
4-73
4-7t
5-54
7-53
9-01
8-44
15-04
15-44
* Tliese Mian Places are not to be used for finding time.
TABLES.
271
Table IV. (continued). — *Mean Places op 50 of the PiiiNcirAL Fixed
Staks for January 1st, 1894.
Name.
Mag.
A.nn. Var.
Declination.
Ann. Var.
+ 3-19
+ 12 29 6-07
-17-47
2-j2
-59 7 38-17
1 18-87
^•74
4-62 19 2j-I2
19-39
3-06
4-15 9 5i'2o
20-I0
m
4-54 17 2'83
20-02
r29
-62 so 41-75
20-00
3-15
-10 j6 28-91
18-87
2-J7
4-49 50 32-45
i8-o6
4-18
-59 51 4i'38
17-57
2-7i
4-19 44 i-80
18-185
4-oj
-60 23 42-68
15-04
J-22
-8 59 30'os
13-48
2-54
4-27 4 17-04
12-29
r48
-19 JO 54-j6
lo-il
3-67
-26 II 47-27
8-27
6 -JO
-68 49 56- 71
7-12
4 98
-55 25 44-69
J -82
2-78
4-12 j8 i4'24
2-8j
2-OJ
4-38 41 6-J7
4- J -20
i-',!
-26 25 40--6
4-18
2-9J
4-8 J5 18-11
9-30
4-78
-57 4 27-18
II-2t
i-8o
-47 28 26-22
17-29
JJJ
— JO II j-05 i
19-01
2-98
4-14 38 5-47
19-3?
li. m. s.
a Leonis {Reg uha) 1 1,2 10 2 4}-6o
7) Argus (var.) j 1-6 104056-95
a Ursse Majoris 2 10 57 11 • 10
/3 Leon is 2 11 4J 39- 16
■y Ursse Majoris 1 2,3 11 48 15-31
a' Ciucis I 122042-21
o Virgiuis (.^pica) , ,. i ij 19 36'4J
>) UrsEB Majoris 2 ij 4J 21-85
/3 Ceutauri i 13 56 20-57
a BoiJtis (^7-ciM>-Ms) I I 141049-55
a2 Centauri 1 14 j2 24-66
/3 LibriE ' 2 15 11 i8-io
a Coronae Borealis (A?p/iecca). . .. 2 15 30 11-96
/31 Scorpii 2 15 59 i6-jj
o Scorpii (Jntares) 1,2 16 22 54-39
a Trianguli Australis 2 16 37 26-48
^ Arse J 17162940
a Opliiuchl 2 17 30 0-79
a Lyrse ( I'e^a) 1 18 jj 20-9;
cr Sagittarii 2,; 1848 41-47
a Aquila; (AUair) 1,2 19 45 j6-65
a I'avonis 2 20 17 15-71
a Gruis I 2 I 22 1 33-07
a Piscis Australis (/•'omaWiai<<) .. ' 1,2 ' 22 51 47-56
a Pegasi (i/dJiai/) .. .. .. .. 2 225928-80
* These Mean Places are not to be used for finding time.
272
HINTS TO THAvr.LLEllS.
r^ -+ r^ -r li-. "^ ^'N -r
- o* •^ r«
00 r* ^ O
•>^ 00 vo M
C* C^ O^ O O O "^
■ O ■'> O r4 ^i^ ci
C r* W yf ir\ \r\ f*\
w oo 'T^
C^ 00 r« ra v«
oooooococo OcT'O^O O O
u^»j%\cor^cooo O O O O
vO M ri sO
« ON -^ oo
o "^r^o C**^*^>o« r^
r4 ri r4 r4 ri
»r^O irvi-M r-O '^C^r* »-i n r) Occ
0(>000 O OwN^O O O G O
>,
a
CX>
^
■r
^
"1
^
S
o
■«•
1^
>^
?
w
-^
?
1^
o
o
ir^
s
•^
s
J3
*H
IH
w
M
"1
M
M
o
"
^
•^
"^
^
*^
""
«^
■«•
•<t-
■<r
f
■^
«#\
.-•
S
HI
-«f
U\
a
^
I^
^
Ft
o
?
Si
vO
^
K
s
;j
?
o
u-\
<J
<V\
•^
;?
•^
N
o
M
^
~N
•^
■^
■4-
■«-
■*
lA
•^
u^
vD
vO
o
>c
o
■c
r
^
•^
•^
?
%
s-
?
z
o
i-
S'
o
o
00
■4-
2;
2^
*H
»n
v\
»^
z
^
53
•=■
"
»H
•^
"
M
M
M
r^
1-
"^
vO
vO
o
vO
O
o
'^
•^
CO
00
00
oo
00
ti^\0 t^oOCOCOCOOOX w^C^CNO O
•^ oc
o o
<v^ r«\ -^
o o o
*0 \0 O^ u^ o
I = §
I 3 t5
I 1
J f -s -n .¥ g r a
I- t; o .=* 3 i; r^ '-
^ 5.
A X -Ss H i
>* S S .£ S
U O -< O o o
.2 c
o
e Ci (O. OQ. CO s
TABLES.
OT^.
?
J^
^
O
o
^
^,
o
<r
»-,
l<^ O
CO o
00 N
sO
„
i>
^
o u-
^.
o
„
^
v\
M
M
IH
1^ m
-1 IH
f
•n
r^
*^
»o
O
t~.
CO
to
>->
f>
o
o
^
M M
n
^ n
*^ f^
n
n
n
^
N ^*S
In
o
sC
"
"
"
M
M
IH
•^
'
■" '^
" "
'
•J n
CO
„
o
^
o
r.
»H
-1-
^
o
c^ -r
ir,
N va
m
o
^
■J a^
o
1-
in
„
u^
M
n
IH
^ 1-
■«•
-r
M
f«
CO
CO
f>
o
o
!_,
M
n
n
O H
(^
'^
j^
00
CO
"
"
M
n
•^
D
M rl
?
„
N
n
o
^
r^
o
o
^
,,
r< O
„
o o
?
w
-o
„
„
o
"^
M
M
•^
»H
n -r
•i in
»A
■* M
**
o
O
IH
M
rJ
«^
^A
f^
o
IH
IH IH
M
■^
■<r
■♦
o
so r~
f^
CT»
O
o
'•'
U
H
^
O
„
CO
-^
„
i/^
fO
r_
„
^
^
^
^
f>
-s
t^
ir\
•^
^^
•^
^ f
-• -r
'A
-r
m
^
ri
rt
•^
'^
o
,.H
M
„
n
r^
^^ ^^
^^
^ f
I
n I/-.
1/-,
o
r-
co c>
,-7s
,^
p^
rl
*^
"
"
'■*
^
"
"
CO
o
o
■^
n
r.
M
■«•
^
r.
o> •«■
irv
•«■ •^
o
^^
^
tT c»
o
in
m
m
*^
*^
^
*^
tr\
«>
< -^
IH «%
■*
■4-
•n
IH
IH
o
O
"
'-'
"
"
W\
~>
•>«■
■^
Ir^ ir\
tr\
so O
'
- r-
•^
00
00
O
o o
IH IH
1:3
IH
1-
f
«,
o
„
,-^
ir-.
„
V^
o
m
^
-1- O
n
r~ -
m
~s
^
^
in
f>
o
^
*^
f^
»'^
'"
^*\
* -"l-
IH Tj-
m
in
■<r
»n
^n
»H
■H
*^
«
'^
f^
-r
ir^
m
«^
vO
^
I- r-
^
OO 00
(^ o>
0^
o
o
IH
IH
M ~s
IH M
IH
m
IH
so
IH
e
,^
1^
>«^
r^
o
■O
O
~.
«
o
■^
IH >n
(^^
^
rJ
sT)
"S 00
O
•r
t-
pj
<^
M
IH *^
rvs Vi
r
< -a-
«s
fn
M
f
■*
lr\
O
o
"^
■^^
•^
00
o
a> o
^
o o
IH IH
IH IH
^
:2
2
in
2" "^
in
E"
CO
M
2.
r-
00
vD
„
C7^
'^
V)
1^
t>
M VO
^
^ oo
^
o
>n
r>
so w
„
so
^
in
^
f^
•H
r
»^
«^ lr\
M -1-
. IH
>H
f^
o
O
'^
»
00
.^
■^
OV
o
M
IH
IH M
IH IH
M
IH IH
IH IH
-f
-1-
IH
»n
IH
O t^
^
IH
8
O
M
o
f>
CO
*^
o
tn
r^
o
o
^
^
r>
r~ r-
vO <7>
„
o
o
r~ r»
00
CO
VO
**»
tri
•-•
'>^
f^
IH M
r
»H rv%
ws
^
•n
M
CO
CO
o
<T>
O
IH
t-4
M
M
•^ •*■
m 1/^
o
si
r—
00 o
O
M
r>
(q
"
"
IH
M
IH
IH
IH
4 IH
"
•"
■ "
"
n
"
ir^
M
^*\
»-(
^
f
IH
^
^
OS ~s
^
ir,
^
„
*^
«%
•^
ir^
V\
»^
«%
IT*
n
T
ft -^
in
-r
M
'l-
^
In
n
IH
IH
o
r.
^
i-l
^
(S|
f^
M^
tT
T^
tr,
VO O
r^ c^
f^
00
CO
fTs
o o
M
n
o
"
M
IH
"
"
"
IH
IH
IH
IH
"
"■
'•
'-'
-
"
IH
"
"^
r»
-*•
M
r«
o
o
~N
^
o
o
~,
in O
IH
fs
O "n
O
„
Ht
r*
■«•
IH
-r
»r^ IH
»»»
U1 C4
'<^
•n
m -^
•n
m
(Si
r>
♦^^
*^
'*^
■+
lr^
f_
o
M
(^
M
"
M
"^
"
IH
IH
IH
H
IH
M
IH
H
"
^
"
M
^
SO
1-
-r
„
»n
O
„
HI
»A
fo
f^
^
O 1-
^
,^
f^
^
m
„
^
w
ir\
»r\
rn
•^
u\
W
■«■
M ■*•
IH in
-<•
-«•
in
^
—
^
■^
v^
m
VO
x^
CO
o o
M M
IH
fg
^
^^
„
in
^
^
M
"
"
M
M
M
IH
IH
IH
'^
M <H
■^
'*
"^
•^
^^
■
^^
•
s
5^
«
•S
-
;<
^
e
^-s
^~^
^-^
-;;
^_^
^.^
.S
^^
s^
^
Cs
■>_
^
■J-
-S
2
'~,'
C
^
.«
«
^^
m
?^
"5
^
5
S"
^
C,
O
V
•r-
:::;
3
3
c
•a
ei
S
s
s
1
s
"Sj
S
^
Z
:|
3
2
r
8
3
cc
" p.
U3
?■
T
n 3,
p
.i
<;
«<
S
-)
•<
p
J
t)
u
>
t3
O
1^
6
3
5
H
-=1
o
H^
<;
d
fe
;;:;
S
fi
■^
e
5!
p
d
CQ.
?-
cj
d
P-
CO
u «
d
ec
I e
QC
L 8
ci
<a.
a
d
t
Cj
ti
13
e
ti
-
^
r<
.,
r.
<^
~>
s n
-
"
-
"
■^
"
"•
274
HINTS TO TKANKl.LKUS.
TaULE VI. — CoRUECTIO>f FOIl THE DaY OF THE ]MoNTII, TO BE Suhliaded FROM
THE APPAUENT TIME OF A StAU's MERIDIAN PASSAGE ON THE FIRsT DAY OF
THE MONTH.
Days
Jah.
Feb.
March.
April.
May.
June.
July.
Aug.
Sept.
Oct.
Nov.
Dec.
li. ni.
Ii. ni.
li. HI.
li. m.
li. HI.
li. m.
h. ni.
li. m.
li. HI.
"n. m.
li. iji.
li. m.
I
2
4
4
4
4
4
4
4
4
4
4
4
4
3
9
8
7
^
8
8
8
8
7
7
8
9
4
ij
12
II
II
II
12
12
12
11
II
12
IJ
5
18
16
15
15
15
16
16
15
14
15
16
17
6
22
20
19
18
19
21
21
19
18
18
20
22
•7
26
24
22
22
2}
25
25
2}
22
22
24
26
8
JO
28
26
26
27
29
29
27
25
25
28
}0
9
is
J2
}0
029
JO
33
33
}I
29
29
J2
35
10
jg
}6
}}
}^
033
35
37
37
35
}2
33
}()
J9
II
4}
40
}G
}<)
041
41
j3
}6
J7
40
44
12
48
044
41
40
42
45
4;
42
40
40
44
48
IJ
52
48
44
44
46
49
49
46
4J
44
48
52
14
56
52
48
48
50
54
5;
50
47
048
52
57
15
I I
56
52
51
OS4
58
57
53
50
51
56
I I
16
I 5
I
55
55
58
I 2
I I
57
54
55
I
I 6
17
J 9
I i
59
59
I 2
I 6
I 5
I I
58
59
I 4
I 10
18
I li
I 7
I 2
I 2
1 6
I 10
I 9
I 5
I I
I 3
I 9
I 15
19
I 18
I II
I 6
I 6
I 10
I 14
I 13
I 8
I 5
I 6
I 13
I 19
20
I 22
I 15
I 10
I 10
I 14
I 19
I 17
I 12
I 8
1 10
I 17
I 24
21
I 26
I 19
I 14
I 13
I 18
I 23
I 21
I 16
I 12
I '4
I 21
I 28
22
I ii
I 2J
I 17
I 17
I 22
I 27
I 25
I 19
1 16
I 18
I 25
I r-
2i
I 35
I 26
I 21
1 21
I 26
I 31
I 29
I 23
I 19
I 21
I }0
1 37
24
I 39
J }o
I 24
I 25
I }o
I 35
I 3;
I 27
I 2}
I 25
I 34
I 41
25
I 4J
I 34
I 28
I 28
I 34
I 39
' 37
I 31
I 26
1 29
I j8
I 46
26
I 47
1 J8
I i2
1 32
I 38
I 44
I 41
I 34
I ;o
I 33
I 42
I 50
27
I 51
142
I 35
I 36
1 42
I 48
I 45
1 J3
I 34
I 37
1 47
I 55
28
I 56
1 45
I 39
1 40
146
1 52
I 49
I 42
I 37
I 41
I 51
J 59
29
2
I 43
I 44
I 50
I 5i
I 53
I 45
I 4«
I 44
I 55
2 3
io
2 4
..
1 46
I 47
I 55
2
I 57
I 49
I 44
I 48
I 59
2 8
31
2 8
I 50
I 59
2 I
1 52
I 51
2 12
TABLES.
275
Table VII. — Mkan Astronomical Eefraction.
(liai ometer, }o inches ; Fahrenheit's Thermometer, 50^.)
A pp.
Refr.
A pp.
Kefr.
A pp.
R?
fr.
App.
.Uefr.
Ait.
Alt.
Alt.
Alt.
/
,
„
/
,
,,
/
,
„
/
,
J,
00
34
17
4 CO
II
47
6 55
30
10 03
5
20
10
32
i;
4 05
II
36
7 CO
25
10 10
5
i;
20
JO
23
4 10
II
26
7 °5
20
10 20
5
10
JO
28
41
4 IS
II
15
7 10
16
10 JO
06
40
27
07
4 20
11
05
7 15
II
10 40
or
50
25
41
4 25
10
55
7 20
07
10 50
5'^
I 00
24
22
4 30
10
46
7 25
n
cj
II 00
52
I 10
23
09
4 35
10
37
7 30
6
59
II 10
48
I 20
22
02
4 40
10
28
7 35
6
54
II 20
44
I JO
21
00
4 45
10
19
7 40
6
5?
II JO
40
I 40
20
02
4 50
10
lo
7 45
6
4''
II 40
36
I 50
It;
09
4 55
10
02
7 50
6
42
II 50
32
2 00
18
20
5 00
9
54
7 55
6
38
12 00
28
2 10
'7
34
5 05
9
46
8 00
6
35
12 10
25
2 15
17
12
5 10
9
38
8 0;
6
31
12 20
21
2 20
16
51
S IS
9
30
8 10
6
27
12 JO
18
2 25
16
31
5 20
9
23
8 15
6
2J
II 40
14
2 }0
16
II
5 25
9
16
8 20
6
20
12 50
4
II
2 JJ
IS
52
s 30
9
09
8 25
6
16
I J 00
08
2 40
15
34
5 35
9
02
8 30
6
13
I? 10
05
2 45
15
16
5 40
8
55
8 35
6
09
I J 20
02
2 50
14
59
5 45
8
48
8 40
6
06
IJ JO
59
2 55
14
4J
5 50
8
42
8 45
6
03
IJ 40
56
J 00
14
26
5 55
8
36
8 50
6
00
IJ 50
5J
3 05
14
10
6 00
8
30
8 55
57
14 00
50
i 10
ij
55
6 05
8
24
9 00
54
14 10
47
i IS
13
41
6 10
8
18
9 05
5
51
14 20
45
J 20
13
27
6 ij
8
12
9 10
48
14 JO
42
i 25
13
13
6 20
8
06
9 IS
45
14 40
40
3 30
13
oo
6 25
8
01
9 20
y
42
14 50
37
i 35
12
47
6 JO
7
56
9 25
39
15 00
J5
3 40
12
34
6 35
•;
50
9 JO
36
15 10
32
3 4;
12
22
6 40
7
45
9 35
33
15 20
30
3 50
12
10
6 45
7
40
9 40
31
15 30
28
3 55
II
58
6 50
7
35
9 50
25
IS 40
25
u 2
276
tIINT8 TO TRAYEl.Lf:ftS.
Tarli: VII. — Mean Astronomical Refraction. — continued.
(Daiom. 30 inches ; Therm, 50° F»hr.)
Cdrrectlons whon Harom.
differs from jo inches or
Therm, from 50° Fahr.
1
Bauometeu.
A pp.
Alt.
Ilcfr.
A pp.
.\lt.
Kefr.
A pp.
Alt.
liefr.
App.
Alt.
For each inch above or
Ix'low 30 inches : — add,
if aljovc 30 ; subtract, if
be'.ow.
/
/
/ 11
'
1 //
"
15 50
i 2J
J I 00
I J7
57 00
J7-9
20
25
30
ii
40
45
50
5
4
i
i
2
2
2
16 00
J 21
Jl JO
I J5
58 CO
?6-5
16 10
i iq
J2 CO
I J?
59 00
35-1 ,
16 20
3 17
J2 JO
I Ji
60 00
JJ-7
16 JO
i 15
JJ 00
I ?o
61 00
J2-4
16 40
J I?
J? io
I 28
62 00
ji-o
16 50
i II
J4 00
I 26
6? CO
29-8
j^
17 03
J 09
34 50
I 25
64 CO
28-5
55
Co
1
17 JO
J 01
35 00
I 2J-2
6; 00
27-2
6;
18 00
2 58
j; 30
I 21-7
66 00
26-0
^?
18 JO
2 5?
36 00
I 20-2
67 00
24-8
'
19 CD
19 J3
2 48
2 -14
36 30
37 00
I l8-8
68 CX3
2J-6
I IT4
69 CO
22-4
20 00
2 59
37 JO
I i6-o
70 00
21-J
THERMOMETEn.
20 JO
2 j;
J8 CO
I 14-6
71 00
20-I
21 00
2 5?
J8 JO
I iJ-3
72 00
i9"o
App.
For each 10 degrees al ovc or
21 JO
2 27
39 00
T I2"0
75 CO
IT9
Alt.
below 50° Fahr. : — iiifc-
22 CO
2 74
39 30
I io'7
74 00
16-7
tract, if atx>vc 50° ; add.
22 30
2 20
40 CO
I 09-5
75 CO
76 00
15-7
f4-6
if below.
2J 00
2 17
41 00
I 07" I
2J JO
2 IJ
42 00
I 048
77 00
ij-5
II
24 OO
2 10
45 CO
I 02'6
78 00
12-4
20
24 JO
2 07
44 00
I oo'4
79 0°
TI'J
2;
25 00
2 0,-
45 00
58-4
80 00
lO'J
30
25 }o
2 Ol
46 00
5<^-i
8t 00
eg- 2
35
lb 00
I 59
47 00
54'4
82 00
o8'2
40
45
50
26 JO
I 56
48 CO
52-6
8! 00
07*2
27 CO
I 54
49 OO
50-7
84 00
o6'i
27 JO
I ii
50 00
49-0
8? 00
o;m
55
28 00
I 49
51 00
47-3
86 00
04-1
60
28 JO
I 47
52 00
45-6
87 00
oj-i
65
29 03
I 45
55 00
44-0
88 00
02'0
70
29 JO
I 4J
54 CO
424
89 oo
OfO
JO 00
I 41
55 00
40-9
90 00
oo-o
JO JO
I 59
56 00
39-4
TABLES.
277
Table VIII. — Semi-diurnal and Semi-noctoknal Arches, showing the time of
THE Rising and Setting op the Sun, Moon, or Equatorial Stars.
Dkclinatiox.
3
D
Lat.
2 3
4
5
6
7
8
9
10
II
12
IJ
Lat.
o
h.
m.
h.
m.
h.
ni. h. ni.
li. m.
h. m.
h. m.
h. m.
b. m.
h. m.
!i. ni.
1). ni.
h. ni.
h. in.
I
6
6
6
6
6
6
6
6
6 I
6 X
6 I
6 I
6 I
6 I
I
2
6
6
6
6
6 I
6 I
6 I
6 I
6 I
6 I
6 I
6 2
6 2
6 2
2
i
6
6
6
6 I
6 1
6 I
6 I
6 I
6 2
6 2
6 2
6 2
6 J
6 J
J
4
6
6
6
6 I
6 I
6 I
6 2
6 2
6 2
6 J
6 J
6 J
6 J
6 4
4
5
6
6
6
6 I
6 I
6 2
6 2
6 2
6 J
6 J
6 4
6 4
6 4
6 5
5
6
6
6
6
6 I
6 2
6 2
6 3
6 J
6 J
6 4
6 4
6 5
6 5
6 6
6
1
6
6
6
6 I
6 2
6 2
6 3
6 J
6 4
6 4
6 5
6 5
6 6
6 6
7
8
6
6
6
6 2
6 2
6 J
6 J
6 4
6 5
6 5
6 6
6 6
6 7
6 7
8
9
6
6
6
6 2
6 i
6 i
6 4
6 4
6 5
6 6
6 6
6 7
6 8
6 8
9
10
6
6
6
6 2
6 i
6 4
6 4
6 5
6 6
6 6
6 7
6 8
6 9
6 9
10
II
f)
6
6
6 2
6 3
6 4
6 5
6 5
6 6
6 7
6 8
6 9
6 9
6 10
11
12
6
6
6
2
6 i
6 J
6 4
6 5
6 6
6 7
6 8
6 9
6 9
6 13
6 II
12
u
6
6
6
2
6 J
6 4
6 5
6 6
6 6
6 7
6 8
6 9
6 10
6 II
6 12
IJ
•4
6
6
6
2
6 i
6 4
6 5
6 6
6 7
6 8
6 9
6 10
6 II
6 12
61J
14
ii
6
6
6
2
6 3
6 4
6 5
6 6
6 8
6 9
6 10
6 11
6 12
6 IJ
614
'5
i6
6
6
J
6
2
6 3
6 5
6 6
6 7
6 8
6 9
6 10
6 12
6 IJ
6 14
6 15
16
17
6
6
6
2
6 4
6 5
6 6
6 7
6 9
6 10
6 II
6 12
614
61;
6 16
n
i»
6
6
6
i
6 4
6 5
6 7
6 8
6 9
6 10
6 12
6 IJ
6 14
6 16
6 17
18
'9
6
6
6
3
6 4
6 6
6 7
6 8
6 10
6 II
6 IJ
6 14
615
6 17
6 18
19
20
6
6
6
J
6 4
6 6
6 7
6 9
6 10
6 12
6 IJ
615
6 16
6 18
619
20
21
6
6
6
3
6 5
6 6
6 8
6 9
6 II
6 12
6 14
6 16
617
6 19
6 20
21
22
6
6
2
6
i
6 5
6 6
6 8
6 10
6 II
6 IJ
6 15
6 16
6 i8
6 20
6 21
22
2!
6
6
2
6
i
6 5
6 7
6 9
6 10
6 12
6 14
6 15
6 17
6 19
6 21
6 22
2J
24
6
5
2
6
4
6 5
6 7
6 9
6 II
6 IJ
6 14
6 16
6 18
6 2o
6 22
624
24
25
6
6
2
6
4
6 6
6 7
6 9
6 II
6 IJ
615
6 17
6 19
6 21
6 2J
625
25
26
(>
6
2
6
4
6 6
6 8
6 10
6 12
6 14
6 16
6 18
6 20
6 22
6 24
6 26
26
27
6
6
2
6
4
6 6
6 8
6 10
6 12
6 14
6 16
6 19
6 21
6 2J
625
627
27
28
6
6
2
6
4
6 6
6 9
6 II
6 IJ
615
6 17
6 19
6 22
6 24
6 26
6 28
28
29
6
6
2
6
4
6 7
6 9
6 II
6 ij
6 16
6 18
6 20
6 22
625
6 27
6 29
29
30
6
6
2
6
5
6 7
6 9
6 12
6 14
6 16
6 19
6 21
6 2J
6 26
6 28
6 JI
JO
}I
6
6
2
6
5
6 7
6 10
6 12
6 14
6 n
6 19
6 22
6 24
627
6 29
6 J2
JI
i2
6
6
2
6
5
6 8
6 10
6 IJ
6 15
6 18
6 20
6 2J
6 25
6 28
6 JI
6 JJ
J2
}J
6
6
J
6
5
6 8
6 10
6 IJ
6 16
6 18
6 21
624
6 26
6 29
6 J2
(> iA
6 j6
JJ
i4
6
6
3
6
5
6 8
6 II
6 14
6 16
6 19
6 22
62,-
6 27
6 Jo
6 JJ
34
J5
6
6
!
6
6
6 8
6 II
6 14
6 17
6 20
6 2J
6 25
6 28
6 JI
6 JA
6 j6
6 J7
J5
J6
6
6
i
6
6
6 9
6 12
6 15
6 18
6 20
6 2J
6 26
6 29
6 J2
6 J9
J6
i7
6
6
J
6
6
6 9
6 12
6 15
6 18
6 21
6 24
6 27
6 JI
6 J4
6 J7
6 40
J7
J8
6
6
J
6
6
6 9
6 IJ
6 16
6 19
6 22
625
6 28
6 J2
6 J5
6 J8
6 42
J8
39
6
6
J
6
6
6 10
6 IJ
6 16
6 20
6 2J
6 26
6 29
6 JJ
6 j6
6 40
64J
39
40
6
6
}
6
7
6 10
6 I?
6 17
6 20
624
6 27
6 JI
6 J4
6 j8
641
645
40
41
6
6
J
6
7
6 10
6 14
617
6 21
625
6 28
6 J2
6 J5
6 J9
6 4J
6 46
41
42
6
4
6
7
6 II
6 14
6 18
6 22
6 25
6 29
6 JJ
6 J7
6 40
6 46
6 48
42
4!
6
6
4
6
7
6 II
6 15
6 19
6 22
6 26
6 JO
6 J4
6 j8
642
6 50
4J
44
6
6
4
6
8
6 12
6 15
6 19
6 2J
6 27
6 JI
6 J5
6 J9
64J
6 47
6 52
44
45
6
6
4
6
8
6 12
6 16
6 20
6 24
6 28
6 J2
6 j6
6 41
6 4;
6 49
6 5J
^,5
46
6
6
4
6
8
6 12
6 17
621
6 25
6 29
6 JJ
6 j8
6 42
6 46
651
655
46
47
6
6
4
6
9
6 \i
6 17
6 22
6 26
6 JO
6 J5
6 J9
6 44
6 48
6 5J
657
47
4^
6
6
4
6
9
6 li
6 18
6 22
6 27
6 Ji
6 J6
6 41
6 45
6 50
6 55
6 59
48
49
6
6
5
6
9
6 14
6 18
6 21
6 28
6 J2
6 J7
6 42
647
652
6 57
7 2
49
50
6
6
5
6
10
6 14
6 19
624
6 29
6 J4
6 J9
6 44
6 49
6 54
6 59
7 6
50
51
6
6
5
6
10
6 15
6 20
62s
6 JO
6 J5
6 40
6 45
6 50
f) 56
7 I
51
52
6
6
5
6
lo
615
6 21
6 26
6 Ji
6 j6
6 41
647
6 52
6 58
' /
7 9
5»
5J
(>
6
5
6
II
6 16
6 21
6 27
6 J2
6 J8
64J
6 49
6 SA
6 56
7
' 2
7 II
Si
54
6
6
5
6
II
617
6 22
6 28
(> ii
6 J9
6 4;
6 50
7 2
7 8
7 14
54
55
6
6
6
6
II
6 17
6 2J
6 29
6 {5
6 40
6 46
652
6 59
7 4
7 I'
7 17
55
56
6
6
6
6
12
6 18
624
6 JO
6 j6
6 42
6 48
654
6 56
7 1
7 7
7 IJ
7 20
S6
57
6
6
6
6
12
6 19
625
6 Jl
6 J7
6 44
6 so
7 i
7 10
7 16
7 1-i
57
58
6
6
6
6
U
6 19
6 26
6 J2
6 J9
6 45
652
6 59
7 6
7 12
7 20
7 27
58
59
6
6
7
6
IJ
6 20
6 27
6 JJ
6 40
6 47
654
7 I
7 8
7 15
7 2J
7 JO
f^
60
6
6
7
6
14
6 21
6 28
6J5
6 42
6 49
6 56 i
7 4
7 "
7 19
7 26
7 H
60
278
11INT8 TO TKAVELLERS.
TaKLIO \'1II. {r(ndilini'll). — SKMI-DH KNAI. and SEMI-XOCTUltNAI, AlilJUES, SHUWlNfi
tup: timi: of rnio Kising and Sktting of tuk Sin, Moon, oit Kv' atokial Stai!s.
])l I IINM luN.
°
00
/
Lat.
14
15
16 17
18 19 '20 21 ; 2li 22 22i 23
2J 23
Lat.
u
li. 111. h. ni. 1). 111. li. m. Ii. ni. li. tn.i Ii. 111. b. 111.
h. in.
h. 111. li. m. li. m. h. ni.
1
61 61 61
61 61 616162
6 2
62 62 62 62
I
2
62 62 62
6 2
63 63 6363
6 3
63 6363
6 3
2
}
63 63
63 64
646.64
f> 5
f' 5
6 ,- 6565
6 5
3
4
6 4.6 4
65 f> 5
6 5 6 6
6 6
6 6
6 6
6 6 67 67
6 7
4
5
65 65 6 6
6 6
6767
6 7
6 8
6 8
6 8 68,69
6 9
5
6
6 6 6 6 67
6 7
6 8 6 8
6 9
6 9
6 10
6 10 6 10 6 10
6 10
6
7
6 T 6 8 6 8
6 q
6 9
6 10
6 10
6 II
6 II
611 6 12 6 12
6 12
7
8
6869
6 8 6 10
6 10
6 u
6 12
6 12
6 13
6 13 6 13 6 14
6 14
6 xZ
8
9
6 9
6 10
6 10 6 II
6 12
6 13
6 13
6 14
6 16
6 14
6 16
6 15 6 15 6 15
9
lO
6 10
6 II
6 12
6 12
6 13
6 14
6 15
6 16 6 17 6 17
6 18
10
It
6 II
6 12
6 13
6 14
6 14
615
6 16
6 17
6 18
6 18 6 18 6 19
6 19
II
12
6 12
613
6 14
6 15
6 16 6 17
6 18
6 19
6 19
6 20 6 20 6 21
6 21
12
U
6 13
6 14
6 15
6 16
6 17 6 18
6 19
6 20
6 2f
6 21 6 22 6 22
6 23
13
14
6 14
6 15
6 16
6 17
6 19 6 20
6 21
6 22
623
6 23 6 24 6 24
625
14
15
6 15
6 16
6 18
6 19
6 20 6 21
6 22
6 24
6 24
6 26
6 25 6 25 6 26
627
1?
l6
6 16
6 18
6 19
6 20
6 21 6 23
6 24
6 26
625
6 27 6 27 6 28
6 29
16
IT
6 17
6 19
6 20
6 21
6 23 6 24
6 27
6 28
6 28 6 29 6 30
631
17
i8
6 19
6 20
6 21
623
6 24 6 26
6 26 6 27
6 27
6 29
6 29
6 30 6 31 6 32
6 n
18
'9
6 20
6 21
6 23 6 24
6 29
6 30
631
6 32 6 33 6 34
634
19
2o
6 21
6 22
6 24
6 26
6 27 6 29
6 30
632
6 33
6 34 6 3i 6 36
6 36
20
21
6 22
624
6 25
6 27
6 29
6 30
632
6 34 6 35
6 36 6 37 6 38
6 38
21
22
623
625
6 27
6 28
6 30
632
6 34
6 36
6 36
637
6 38 6 39 6 40
6 41
22
2J
624
6 26
6 28
6 30
632
634
6 38
6 38
6 39 6 40 6 42
6 4!
23
24
6 25
627
6 29
631
633
635
637
6 39
6 40
6 41 6 42 6 44
6 43 6 45 6 46
645
24
25
627
6 29
631
6 33
6 35
637
6 39
6 41
6 42
647
25
26
6 28
6 30
632
6 34
6 36
6 36
6 39
6 41
6 43
644
64; 6 47 6 48
6 49
26
2T
6 29
631
634
6 38
6 40
6 4J
6 45
646
6 48 6 49 6 50
651
27
28
6 }0
63}
635
6 37
6 40
642
6 4;
6 47
6 48
6 50 6 51 6 52
^5J
28
29
6 J2
6 34
6 37
6 39
6 42
6 44
647
6 49
6 50
6 52 6 53 6 54
6 56
29
30
633
6 36
6 38
6 41
6 43
6 46
6 49
651
653
6 54 6 55 6 57
6 56 6 58 6 59
6 58
30
31
634
6 37
6 40
642
645
6 48
651
653
655
7
31
32
6 36
6 39
641
6 46
647
6 50
(> Si
6 56
657
6 58 70 72
7 3
32
3J
637
6 40
64J
6 49
6 53
655
6 58
6 59
71 7 2 74
7 5
33
34
6 39
642
6 45
6 48
651
6 54
6 56
657
7 °
7 2
7 3 7 5 7 7
7 8
34
35
6 40
6 4?
6 46
6 49
653
6 59
7 2
7 4
76 77 79
7 II
35
36
6 42
645
6 48
65.
655
6 58
7 I
7 5
7 7
78 7 10 7 12
' 'i
36
31
643
6 47
6 50
6 53
657
7
]t
7 7
7 9
7 II 7 15 7 15
7 16
37
38
645
6 48
652
655
6 59
7 2
7 10
7 '2
7 14 7 16 7 17
7 16 7 18 7 20
7 19
33
39
6 47
6 50
^6^^
657
7 I
7 5
7 9
7 12
7 14
7 22
^9
40
648
6 52
6 59
■7 J
7 7
7 II
7 15
7 17
7 19 7 21 7 23
7 25
40
41
6 50
654
6 58
7 2
7 6
7 10
7 14
7 18
7 20
7 22 7 24 7 27
7 29
41
42
652
6 56
7
u
7 8
7 12
7 17
7 21
7 2?
7 25 7 28 7 30
7 32
42
43
^54
6 58
1 2
7 II
7 15
7 19
7 24
7 26
7 29 7 31 7 33
7 36
43
44
6 56
7
7 4
7 9
■^ H
7 18
7 22
7 27
7 29
7 32 7 34 7 37
7 39
44
'^j
6 58
7 2
7 7
7 II
7 16
7 21
7 25
7 30
7 JJ
7 35 7 38 7 40
7 4?
45
46
7
7 4
7 9
7 '4
7 19
7 24
7 29
7 34
7 36
7 39 7 4' 7 44
7 4"
46
47
7 2
7 7
7 12
7 17
7 22
7 27
7 32
7 37
7 40
7 41 7 46 7 48
7 51
47
48
7 4
7 9
7 14
7 19
7 25
7 30
7 ?5
7 41
7 44
7 47 7 50 7 53
7 55
48
49
7 7
7 12
7 17
7 22
7 28
7 33
7 39
7 45
748
7 51 7 54 7 57
8
49
50
7 9
7 14
7 20
7 25
7 31
7 31
7 43
7 49
7 52
7 55 7 58 8 2 8 5
50
51
7 12
7 17
7 23
7 29
7 35
7 41
7 47
7 53
7 56
80 83 86 8 10
51
52
7 14
7 20
7 26
7 32
7 38
7 45
7 5;
7 58
8 I
85 8 8 8 i2 8 15
52
53
7 17
7 23
7 29
7 36
7 42
7 49
756
8 2
8 6
8 10 8 13 8 17 8 21
53
54
■7 20
7 27
7 33
7 40
7 46
7 5?
8
8 8
8 II
8 15 8 19 8 23 8 25
54
5|
7 23
7 30
7 37
7 44
7 51
7 58
8 5
8 U
8 17
8 21 8 25 8 29 8 3J
8 27 8 32 8 36 8 40
55
56
7 27
7 34
7 41
748
7 55
8 3
8 II
8 19
8 23
56
57
7 30
7 37
7 45
7 52
8
8 8
8 16
8 2;
8 29
8 34 8 39 8 43
8 48
57
58
7 34
7 42
7 49
7 57
8 5
8 14
8 22
8 32
8 36
8 41 8 46 8 51
8 56
58
1?
738
746
7 54 , 8 2
8 II
8 20
8 29
8 39
844
8 49 8 54 9 °
9 5
59
60
742
7 51
7 59 , 8 8
8 17
8 26
8 36
8 47
852
8 58 93 9 9 9 15
60
TAULKS.
'27i)
Table IX. — Distance of thk Sea Horizon uncoijrecied Foit effects of
liEFltACTION.*
Ileiglit.
Dis-
tance.
Height.
Dis-
tance.
Height.
Dis-
tance.
Height.
Dis-
tance.
Height.
Dis-
tance.
Height.
Dis-
tancc.
Feet.
1 I
.Mile.=.
Feit.
^90
Miles.
21
Feet.
1487
Miles.
41
Feet.
329?
Jliles.
61
Feet.
9032
Miles.
101
Feet.
17608
Miles.
141
3-5
428
22
1561
42
3513
63
9393
103
18111
14;
8-0
468
2}
1636
43
3740
65
9760
105
18622
145
14-2
510
24
1713
44
3974
67
10135
107
19140
147
22-1
550
25
1792
4;
4213
69
10518
109
19664
149
.11 -9
6
598
26
1872
46
4461
71
10908
III
20197
i;i
4ii
7
645
2-
1954
47
47"'
7;
11304
113
207 j6
15J
56-6
8
694
28
20J9
48
4976
75
11709
115
21232
155
''•7
9
744
29
2124
49
5249
77
12120
117
2l8j6
157
88-5
10
797
30
2212
50
. 5524
79
12538
119
22397
159
107
II
850
31
2JOI
51
5808
81
12966
121
22964
161
127
12
906
}1
239}
52
6098
83
13397
123
23540
163
M9
1}
964
3 J
2485
53
('i9-i
85
i;8;6
125
24121
165
17!
14
I02i
34
2581
54
6700
87
14282
127
247II
167
!()■)
15
1084
35
2677
55
7012
89
14737
129
25307
169
226
16
"47
36
2775
56
7332
91
15197
131
25911
171
256
«7
1211
37
237;
57
7656
93
15664
133
26521
173
287
18
1278
38
2977
53
7987
95
16139
IJ5
27139
175
3>9
19
IJ46
39
3081
59
8330
97
16622
137
27764
177
J 54
20
1416
40
3186
60
8678
99
17111
139
28J96
179
(Aj)proximately the distance visible in miles is the square root of the height in feet, an acci-
dental relation easy to remember.)
* The effects of refraction at low angles are very variable, but in ordinary Ciises, if the height
of observer be supposed to be increa.sed by one-third, the distance of the visible .=ea horizon will
not exceed the tabular value corresponding to the revised entry. Extraordinary cases are lliise of
mirage, &c., for which no general lule can be given.
280
HINTS TO tram;lij:ks.
Ml
I ^A l/^^o r-OO O *^ «*» '*! »r.O i^oo O '
« l^NsC t-30 O
r« r^ .^ ^ -r -r 't -r ■^ -r -r -i" tr, ^r^ »rv I/-, If , M-, u". u-,0 OnO^JsC^^OO^
. I
-co a^ O M *^ ^ irsNO r-00 O^^ r^ ^*\ ^ ifisO r-00 O t^ <^ '^ "t- ir ^o oo C^
^%0^ r-r—r-r-r-r-r^r-r-oocooooooooooooo c^c^^c^O^^C*^^
o* O »-• n ■^"^'O r-"00 O Q »^ n
OOOOOOOM.-.MMWMM
»r\0 r-r-ooo^Ow f^ '^ •f irvso r-00 c^^o wr**^ *^lf^o r-00 ^ o *^
0OO3CO00000O ONO^OOOOC^Oa^O^OO O O O QOQO QO*-«-
ri )^^ *^ -^ irwo r^OO ^ O O 1
N \f\\C> r^co C^ O I
; r
, Tf iTi'O r- r-oo O^O mmm <^<^■*f■^r^ »*s%0 r-oo O^^^Q >* *
" CO CO oo 00 00 00 O^ 0>^0^C^ ^ CT^CT*O^C^ C^CT* 3* '^
OCCOOOCOCOOOOOOOOO C^0^C^0^OC^CT^CT*C^C^C*CT*^*0 O O O O O O
~ ^
xr> r^oo COC^OOi-inM'^ ■^T^Ir^^O^O ^»<g g^O 0»-««N '^'^'^fv
o
M^H„MM(S(sn(Sr4r4<sr4fiNr4nr*<s(sr*n(sc4r*<sr<r*r4
g
»*"OOnOO vOvOO nOOnOOO sO <C >C>00 r- i^ r- t-- 1- r- r- 1— r- r^ r-
H
^C O r^r-30 ooa^a^OOw««^•^"^ n- •*• u-^^ »'^sO >0 r- r-30 00 O O O —
O r- r— oo JO 00 O ^ O O
•^ »s^ -^ -^ ir\ u%so o r- r- r-oo oo c^ C
C^O^^^O^^C^C^OOOOOOOOOOOOOOOOOOOOO
> u^o O r- r- r-oo ooo^ct^O 00^-i-tr»r«
~r^ IT* r- r- i-* r- 1— t-* r- r-30 oo oo oo oo oo co
OOOOOMwwr*
»riir\U-tinir\ir»irt>r\i
^ ir\0 \0 O r^ r-00 OC CO C7*
^ ^ ^ -f.T^■^t
^ m»o O-O r— r-r— r— oocooo C^C^C^
•ppnoooc;
COOOOOOOOOOO 0^a^^l^l3^0^0^0 O O O O O O
ri n ri r* N n N (v\^*>f*\»^'^'*\«N'*>'*''^'^'^^'f^"t""^^^^
OOOOOOOOOOOOOOOOOOOOOOOOOOOOO
O w r^ «^ "f »^'0 r-00 c^ O «-• N <^ Tf- i'^>o r-oo o^o « f* i^ ^ »/^^c r-oo
TABLES.
281
M-iO r- :?" O "-< ^'^ "^ ir^^O CO ON O HI »A «
rwC O O O ^ ■^ ^ O
> r-oo c^ M rv»^ ff-^ i—oo O '-' '
O^n '^t »^0 CO o o '
' "^ l<^0 r^ O^ O '-' M 't->'''0 r^oo o '-' *^ '■- »'nO r--
-■ 30CO c^c^c^oc^c^C^C*•0 O O O o o O
OOOOOOOOO
•^ "^ »^«C CO ^ O tH '
<5s0O<?O^OOOO<5OO'OO^<5^0'O<)O^O'»COOO'O'«0O'O
•^ rf- ij^O CO On O
> ■^i^'O r-oo O f
\ ^ TrT^-f-^<rTf•t-^T^Tfl
r<^ -^ irsO r-OO OO r» '-iTj-ir\sO
^lr^lrtU^u^tolr^lr^u^u^t#^u^u^lr^lr^u^t
O M ^ «^ irvvo r*00 O^ O M ri f^ Ti- iTiO r^oo O O m n ^ ^ ir»0 r-oo O C
1^ 1^ r-r^ r-"r^ t— r^ r— ao cooooooooooooooooo o^(:y^<^o^<y^o^o^O'^<y^^i
r» ^A Tf tTN ir^O r^co On O w rJ *^ T^ itnO t^oo C7^ O w r4 »^ -^ \t\\n r-co O^ O w
■^ ir\0 r^ r-oo Cn O >-< r» »vs "^t- ir\sO O r^oo C^ O w i
\ u^ u^o nD vO O O O O \0 vO nO >0
O O O O O
ON O »H r) rJ »v^ ■^ l*^^o r- r-oo 0*0 w ri N f^-^iri-o r-r-oo O^O •-•
■*f >f^O O r-co 0*ONO wM '^•M,Tf ir-sO <; r- 00 O^ 0> O "-I '
^'^O OO'OOO^sO'O'OOO^'O r— c^i^
r* (S *s r4 c4 <
I (N M PJ r<
NO nO r-oo ooONO M >-« •^•^■^WN i^o r-oo oo O^ O O '
rir4r)r4nMnr4<sp4tsr<Mc^(^r4Nnc4C]NN(
300 i^O O MNrlf^rATj-iA »r\>0 r-
- 1- 1^00 oooooocoocoocoooooooooe
;oO ONO O >-> ri n '^'I'-t-irvO
JOOCO OnOnOnOnOn^Cn^Cnon
h- rJ rJ <^ f^ n- >'^ \*^^0 nO t- r-00 OnOO O i-- »-' n r^ '■'\ -rf- ff- V^ »'nO
1-1--r'^f■^--1-■^1-'r'r■^-r'^■^u^^^u^u-,»*-^^^^#^»<-^^^u^^^u^
0'-<>-"r»r*»^i^rt-Tf-ir\ wnsC nO t^ t^OO CO OnCnO O *-■ t-" r^ N ^*\ -^ -r ir- tr\
> »r\0 sO r^ r^oo <
* -^ -rftrs VwO
;oooooooooooooocooooooooo onononOnOno^ono^ononono^o^On
OnCnO O O 1- Mr«nr< •^•^*^-1-'l-^tr\ itinD O nC i
> 00 00 ON O^ ONQ O
»r\ lr\*0 OO'O'OnOnOOO^nOOOOnOO^OOOvO^nOO'OOnO'O
l^-f■<f^Tt-■^T^-t-Tt--i-1-rt-r^'r■^
$^'-?
■^"^'i-^'=f1--^f-1-'^-^-f
-r-r-oooococo OnO^cncnO O O O
\ f^ ■+-t*Tt'r}-'i--«^u^lrMr\»r\ ir^O \0 O nO \0 O
TfTt•N^lnu^^AU^w^v^u^t'^ itnO OiOOnOnOvOOO r-i
-r^r-*oo 00
CT* O •- <** '^ "^ t*^v£^ r-oo O O "-i r) ^^ -^ ^r^^O t— 00 0*0 >- n »^rfir\0 I- CO On
282
HINTS TO TRAVELLERS.
OCL,
H P
f=^ 'k.
p. P5
W «
9 K
^
o *
o
o^
*t-
1^.
fKl
r^
ri
?
n
M
-^ ^
vO
^*.
'T
8
-t-
;1-
^■
^
*o
u 5)
^ V
b-
90
V
b
l«
^
►■■
M
M
- _- ^^
GJ -^ ,
1^1
o f-
o»
M
-^
ir\
v£)
00
^
CO
00
CO
oc
00
CC'
_^ -^ *-*
<— C
^
O (^
t..
o
o
rl
vO
M
'^
T
M
n
s^
if.
CO
1^
J oj
o
-»-
-r
CC
oc
f^
;1-
f
tJD 5}
c ^
^ h^
00
■i
-1-
b
c^
00
oJO
n
■-J
_ ,
Hi
o ^
»^
■+
u>
vO
00
0^
n
»^
■^
•ft
vC
VO
»o
VD
vC
r-
«!.-;■
ft. -
(.-
^ o o^
f^
O
r^
ft
1-
VN
ir
r-.
r^
1-
q^
[-«
1-
c-
1-
^
<7*
ei 3] •"
o
^
-1-
f
co
»-"
^
r^-
00
^
0"
b
b
'?"
00
^
^
■O
tr\
^
'-I
^
l^
b
b
ojO ^
■<r
T
"^
f^
^^
^^
•^
f^
f^
*^
•^
■— • 1
~ 1-S ^
»rs
-r
T
-1-
lr\
\r\
»''
t*~,
»^
W^
\r^
I/-,
u^
|5^"
«.-!
o . ,^
o
O
r.t
f)
If
X
irf
v»
■^
oc
^
\r^
c^
-1-
^
a^
tn t- -r
o
^^
■0
•f
bC CO
b
b
'c
V
o Q *'^
-1-
-r
^
-1-
-r
-r
-r
-r
f
-J-
1-
1-]
1— 1 1 j
r»
w^
1-
lr\
«
M
'+
r*s
rft
-r
-r
-r
Tf
-^
-♦•
-=Sv.-^
ft- o 1
c .
o
^
i_,
^
"^
cc
r-
cc
r-l
^
^C
ir\
oc
•1-
J3 S
c-
o
cc
^
sO
C>
-f, =-
o
•t-
vO
^
■•r
ir\
tc to
C V
i
i
V
^-
»^
^Q
lr^
l#N
ir\
i#%
w^
ir\
ir\
tr\
u^
u%
»#^
*r\
»r\
"5 •— .
^ «-
„ ^
-^
oc
C" 5
O H«
»-•
>-•
•"•
f^
(^
f^
(S
r)
rJ
(^
M
*^
(i; o
<«
o ^
o
^
•3-
X^
-1-
p'\
»v
^
^
^.^
)«^
i^
n
^
CC
o
^
C^
^
CO
r""
1^
T
(^
C^
>c
-r
f^
^
~ b
c>
c<
c>
<>
'0
'0
^
C>
"0
OC
oc
cc
CO
^
fca
VO
ir\
ir\
u^
ir%
t**,
ir\
•"
.^
|3|'
o O
M
r»
<»\
■*
>r,
VO
•^
30
^
:i
«
-^
^
ci !._, w
ft- o
TABLES.
283
Table XII. — Table for converting Statute into GEOCRArnicAL ^Miles.
Stat. M iles.
Geo. Jliles.
Stat. Miles.
Geo. Miles.
Stat. Miles.
Geo. Miles.
Stat. Miles.
Geo. Jlilcs.
i-co
87
15-25
11-50
25-50
22-11
37-75
32-78
1-2;
I -03
1)50
11-72
25-75
22-36
38-00
33-00
1-50
l-io
1375
II -94
26-00
22-58
38-25
33-21
1-75
1-52
14-00
12-16
26-25
22-80
38-50
3!-4J
2-03
1-74
14-25
I2-J7
26 50
23-01
38-75
3!-65
2-25
1-9;
14-50
12-59
26-75
23-23
39-00
3{-87
2-50
2-17
14-75
I2-8I
27-00
23-45
39-25
34-08
2-75
2-J9
15-00
li-oi
27-25
23-66
39-50
34-30
j-oo
2-60
15-25
13-24
27-50
23-88
39-75
34-52
}•!$
2-82
15-50
13-56
27-75
24-10
40-00
34-7J
J-50
J -04
15-75
1^-63
28 00
24-31
40-25
34-95
^•75
J-26
16-00
13-89
28-25
24-53
40-50
35-17
4-00
J-48
16-25
14-11
28-50
24-75
40-75
35-J8
4-25
J-70
16-50
ira
28-75
24 9-7
41-00
3=;-6o
4-50
J -91
16-75
14-55
29-00
25-18
41-25
35-82
4-75
4-12
17-00
14-76
29-25
25-40
41-50
36-04
5-00
4-^4
17-25
14-98
29-50
25-64
41-75
36-25
5-25
4-56
17-50
15-20
29-75
2i-83
42-00
36-47
5-50
4-78
17-75
15-41
JO-CO
26-05
42-25
36-69
5-75
4-99
I8-O0
15-63
30-25
26-27
42-50
36-90
6'oo
5-21
13-25
15-85
io-5o
26-48
42-75
37-12
6-25
5-4J
18-50
16-06
^0-75
26-70
43-00
37-34
6 -50
5-64
18-75
i6-23
ji-oo
26-92
4? -25
37-55
6-75
5-86
19-00
16-50
31-25
27-13
4? -50
37-77
•J-OO
6-o-i
19-25
16-72
31-50
27-35
43-75
37-99
7-2?
6-^0
19-50
16-93
ii-75
27-57
44-00
38-21
7 '50
6-ii
19-75
17-15
32-00
27-79
44-25
38-42
7-75
6-7J
20-00
i7-i7
32-25
28-ot
44-50
38-64
8-00
6-95
20-25
17-58
32-50
28-22
44-75
38-86
8-2S
7-16
20-50
17-80
32-75
28-44
28-66
45-00
39-07
8-50
TJ8
20-75
18-02
33 -oo
45-25
39-29
8-75
7-60
21-00
18-24
33-25
28-37
45-50
39-51
900
7-81
21-25
18-45
33-50
29-09
45-75
39-72
9-25
8-oj
21-50
18-67
iJ-75
29-31
46-00
39-94
9-50
8-25
21-75
18-89
34-00
29-53
46-25
40-16
9-75
8-47
22-00
ig-io
34-25
29-74
46-50
40-38
lo-co
8-68
22-25
19-32
34-50
29-96
46-75
40-59
10-25
8-90
22-50
19-54
19-76
34-75
30-18
47-00
40-81
10-50
9-12
22-75
35-00
30-39
47-25
41-03
10-75
9-i}
2J-00
19-97
35-25
30-61
47-50
41-24
II -OD
9-55
2r25
20-19
35-50
30-83
47-75
4«-f>
41-68
11-25
9-77
23-50
20-41
20-62
35-75
31-0^
31-26
48-00
11-50
9-99
2r75
36-00
48-25
41-8,
11-75
10-20
24-00
20 -J4
36-25
31-48
48-50
42-11
12-03
10-42
24-25
2i-o6
36-50
31-70
48-75
42-33
12-25
10-64
24-50
21-28
36-75
31-9'
49-00
42-55
12-50
10-85
24-75
21-49
37-00
32-13
49-25
42-76
12-75
11-07
25-00
2I'7I
37-25
32-35
49-50
42-98
li-oo
11-29
25-25
21-9?
37-50
32-56
49-75
50-00
43-20
43-42
284
HINTS TO TRAVELLERS.
Tablk XIII. — Fan convioiiting Geoguaphical into Statutk Miles.
Geo. Miles.
Stat. Miles.
Geo. Miles.
Slat. Miles.
Geo. Miles.
Stat. Miles.
Geo. Miles.
Stat. Miles.
l-oo
1-15
ir25
15-26
25-50
29-3*^
37-75
43 -M
1-2S
i"44
H-50
15-54
25-75
29-66
38-00
45-63
1-50
I-7J
ir75
15-8J
2') -00
29-94
38-25
45-92
i-IJ
2-OI
14-00
1612
26-25
3023
38-50
44-20
2-O0
2-iO
14-25
16-41
26-50
30-52
38-75
44-49
2-25
2-59
14-50
16-70
26-75
30-81
39-00
44-78
2- SO
2-88
14-75
16-98
27-00
31-09
39-25
45-07
2-75
i"i7
15-00
17-27
27-25
31-33
39-50
45-35
3-0O
i-45
15-25
17-56
27-50
31-67
39-75
45-64
yiS
i-7+
15-50
17-85
27-75
3t-95
40-00
45-95
l-$o
4-oj
15-75
18-14
28-00
32-24
40- 25
4621
i-lS
4-J2
i6-oo
18-42
28-25
32-5?
40-50
46-50
4-00
4-61
16-25
18-71
28-50
32-3r
40-75
46-79
4"25
4-89
16-50
19-00
28-75
33- 10
41-00
47-07
4-50
5-18
16-75
19-28
29-00
33-39
41-25
47-36
4"75
5-47
17-00
19-57
29 25
33-68
41-50
47-66
5-00
5-76
17-25
19-86
29-50
3r9^
41-75
47-95
5-25
6-o4
17-50
20-15
29-75
34- 25
42-00
48-23
5- 5"
6-j}
17-75
20-44
io-00
34- 54
42-25
48-52
5"7;
6-62
18-00
20-7?
30-25
34-82
42-50
48-81
6-0O
6-qi
18-25
21- 01
JO- 50
35 II
42-75
49-09
6-25
7-20
18-50
21-^0
Jo-75
35-40
4roo
49-38
6-50
7-48
13-75
21-59
JIOO
35-68
45-25
49-6-
6-75
7'77
19-00
21-88
Jl-25
35-97
45-50
49-95
7-00
8-o5
19-25
22-17
ji-50
j6-26
45-75
50-24
7-25
8-J5
19-50
22-45
31-75
36-55
44-00
50-33
7-50
864
19-75
22-74
32-00
36-83
44-25
50-82
T75
8-92
20-00
2J-OJ
32-25
37-12
44-50
51- 10
8-00
9-21
20-25
zyn
32-50
37-41
44-7;
51-39
8-25
9-50
20-50
2r6i
32-75
37-69
45-00
51-68
8-50
9-79
20-75
21-89
33-00
37-98
45-25
51-96
8-75
10-07
2I-00
24-18
3J-25
38-27
45-50
52-25
9'co
9-25
10- j^
21-25
24-47
33-50
38-55
45-75
52-54
10-65
21-50
24-76
33-75
38-84
46-00
52-83
9-50
10-94
21-75
25-04
34-00
39-13
46-25
53-11
9"75
11-2}
22-00
25-J?
34-25
39 42
46-50
53-40
5369
lo-oo
11-51
22-25
25-62
34 "50
39-70
46-75
10-25
11-80
22-50
25-91
34-75
39-99
47-00
55-97
10 50
12-09
22-75
26-20
J5-0O
40-28
47-25
54-26
10-75
12-i8
2J-OD
26-48
35-25
40-56
47-50
54-49
IIOO
12-67
2r25
26-77
35-50
40-85
^17- 75
54-83
11-25
12-95
2J-50
27-06
35-75
41-13
48-00
55-12
11-50
ir24
2J-7?
27->'5
36-00
41-42
48-25
55-41
11-75
U-5J
24-00
27-64
36-25
41-72
48-50
55-70
I2-0O
lj-82
24-25
27 92
56-50
42-01
48-75
55-98
12-25
14-11
24-50
28-21
36-75
42-30
49-00
'^■';
12-50
I4-J9
24-75
28-50
37-00
42-58
49-25
56-56
12-75
14-68
2500
28-79
37-25
42-77
49- 5C'
56-84
IJQO
14-97
25-25
29-07
37-50
43 -06
49-75
50-00
57-13
5742
I'AbLES.
285
Table XIV. — Comparison of Thermometer Scales,
Fahrenheit.
Reaumur.
Centigrade.
Fahrenheit.
Reaumur.
Centigrade.
Fahrenheit.
Reaumur.
Centigrade.
o
3i
+ 0-4
4- 0-6
67
4-15-6
4-19-4
o
-14-2
-17-8
34
0-9
I-l
68
l6-o
20-0
I
ir8
17-2
3S
13
1-7
69
16-4
20-6
2
IJi
i6-7
J6
1-8
2-2
70
16-9
21-1
}
12-9
i6-i
31
2-2
2-8
71
17-i
21-7
4
12-4
i;-6
i8
2-7
3-3
72
17-8
22-2
5
I2-0
i;-o
39
JI
i-9
7;
18-2
22-8
6
II-6
14-4
40
r6
4-4
74
18-7
2i-3
1
II-I
ir9
4t
4-0
5-0
75
19-1
2r9
8
IO-7
ir;
42
4'4
5-6
76
19-6
24-4
9
10-2
12-8
4 J
4-9
61
77
20
25-0
lo
9-8
12-2
44
5V5
6-7
78
20-4
25-6
II
9i
II-7
4?
5-8
7-2
79
20-9
26-1
12
8-9
II-I
■\^>
6-2
7-8
80
2I-;
26-7
1{
8-4
IO-6
47
6-7
8-3
81
21-8
27-2
14
8-0
lO'O
4''^
7-1
8-9
82
22-2
27-8
I?
7-6
9-4
49
7-6
9'4
8j
22-7
28-j
i6
7-1
«•'>
50
8-0
lo-o
84
2J-I
28-9
17
6-7
8-i
5t
8-4
ID-6
85
2r6
29-4
i8
6-2
7-8
5J
8-9
II -I
86
24-0
30-0
19
5-8
7-2
5?
9-3
II-7
87
24-4
JO -6
2o
5"i
6-7
54
9-8
12-2
88
249
jii
21
4-9
6-1
55
10-2
12-8
89
25-;
Ji-7
22
4-4
5-6
56
10-7
IJ-J
90
25-3
J2-2
2i
4-0
5-0
57
II-I
IJ-9
91
26-2
32-8
24
r6
4'4
58
II-6
14-4
92
26-7
JJJ
25
Ji
i-9
59
12-0
15-0
9?
27-1
J {-9
26
2-7
JJ
6o
12-4
15-6
94
27-6
^44
27
2-2
2-8
61
12-9
16- 1
95
28-0
J5-0
28
1-8
2-2
62
IJ-J
16-7
96
28-4
J5-6
29
I-J
1-7
6j
ir8
17-2
97
28-9
J6-.
?'3
0-9
I-l
^^4
14-2
17-8
98
29-J
J6-7
jl
-0-4
-0-6
f.;
14-7
18 -J
99
29-8
37-2
"
o-o
o-o
66
+ 151
4-18-9
100
..0-2
4-J7-8
x^ Reaumur = (32° 4- | x°) Fahrenheit ■= \x° Centigra<Ie.
x° Centigrade = (j2° 4- -| x°) Falirenheit = ^_ x° Reaumur.
x° Falirenlieit = J (x' - J2) Iti'-aumur = I (u:° — J2°) Centigrade.
280 HINTS 'J'U TllAVELLEltS.
Taulk XV. — Van convekting Encij.sh Inciiks and Tkntiis into Millimethkh.
Kiiglisli
1
Knglish
Knglisli
I'.nglisl)
KnKlish
Inches
and
1 Alilliin.
indies
and
Millini.
intlifs
and
Millini.
inclics
and
iMilliin.
indifs
and
Millim.
tenths.
tonths.
tfiiths.
tenths.
tf.-nths.
12-0
304' 79
i6-o
406-39
20-0
507-99
24-0
609-59
28-0
•711-19
I
10T33
I
408-9}
I
510-53
I
6f2-|J
I
7'?-7J
2
^09-87
2
411-47
2
513-07
2
614-67
2
716-27
3
JI2-4I
3
414-01
3
5i;-6i
3
617-21
i
718-81
4
JI4-95
4
416-5;
4
518-15
4
619-75
4
721-35
5
ii7-49
5
419-09
5
520-69
5
622-29
5
723-89
6
J2O-0J
6
421-6J
6
523-23
6
624-83
6
726-4}
■7
J22-57
7
424-17
426-71
7
525-77
7
627-37
7
728-97
8
i25II
8
8
528-31
8
629-91
8
731-51
9
32-,-6s
9
429-25
9
530-85
9
632-45
'>
734-05
Ji-o
3 JO- 19
17-0
451-79
21-0
533-39
25-0
634-99
29-0
736-59
I
iJ2-7J
I
4M-J3
r
535-93
I
637-53
I
739-U
2
JJ"27
2
436-87
2
538-47
2
640-07
2
74' -67
J
3;7-8i
3
439-41
3
541-01
3
642-61
3
744-21
4
M°'!!
4
441-95
4
543-55
4
645 15
4
746-75
5
342-89
5
444-49
5
546-09
5
647-69
5
749-29
6
J45-45
6
447-03
6
548-63
6
650- 23
6
751-83
1
J4T97
7
449-57
7
551-17
7
652-77
7
754-37
8
ijo-si
8
452-11
8
553-7'
8
655-31
8
756-91
9
i5i-05
9
454-65
9
556-25
9
657-85
9
759'45
14-0
i?rs9
i8-o
457-19
22-0
558-79
26-0
660-39
30-0
761-99
I
J53MJ
I
459-73
I
561-33
I
662-93
X
764-53
2
360-67
2
462-27
2
56J-87
2
665-47
2
767 07
i
363-21
3
464-81
3
565-41
3
668- 01
3
769-61
4
365-75
4
46- -35
4
568-95
4
670-55
4
772-15
5
368- .-9
5
469-89
5
571-49
5
675-09
5
774-69
6
370-83
6
472-4?
6
574-03
576-57
6
675-6}
6
777-23
n
373-37
7
474-97
7
7
678-17
7
779-77
8
37;-9i
8
477-51
8
579-11
8
680-71
8
782-31
9
i78-45
9
480-05
9
581-65
9
683-25
9
784-85
I5-0
380-99
19-0
482-59
23-0
534-19
27-0
685-79
3I-0
787-39
I
383-53
I
485-1;
I
586-73
I
6g8-}3
1
789-9}
2
386-07
2
487-67
2
589-27
2
690-87
2
792-47
3
388-61
3
490-21
3
591-81
3
693-41
3
795-01
4
39' 'I?
4
49275
4
594-35
4
695 95
4
797-55
5
395-69
5
495-29
5
596-89
5
698-49
6
39*^ -23
6
497-83
6
590-43
6
701-03
•7
393 •/ 7
7
500-37
7
601-97
7
703-57
8
401-31
8
502-91
8
604-51
8
706-11
9
403-85
9
505-45
9
607-05
9
708-65
Parts to be added for Hlndi;edtus of an Incu.
•254
762 i-oi6 1-270 1-524 1-778
2-286
TABLES.
287
TaBLK XVI. — CONVEKSIOX OF MtTIJES INTO ENGLISH FeET.
1 to 210.
Metres
Feet.
Metres
Feet.
Jletres
Feet.
Mitres
Feet.
Metres
Feet.
iletres
Feet.
I
r28
36
118-11
71
232-94
106
347-78
141
462-61
176
577-44
2
6-56
37
121-39
72
236-22
7
351 06
42
465-89
77
580-72
3
9-84
38
124-67
73
239-51
8
354-34
43
469-17
78
584-00
4
iri2
39
127-96
74
242-79
9
357-62
44
472-45
7c
587-28
5
i6'4o
40
131-24
75
246-07
10
360-90
45
475-73
80
590-56
6
19-69
41
134-52
76
24935
III
364-18
146
479-01
181
593-84
■7
22-97
42
137-80
77
252-63
12
367-46
47
482-29
82
597-12
8
26-25
43
141-08
78
255-91
13
370-74
48
485-57
83
600-40
9
29-53
44
144-36
79
259-19
14
374-02
49
488-85
84
603-69
10
32-81
45
147-64
80
262-47
15
377-30
50
492-13
85
606-97
II
36-09
46
150-92
81
265-75
116
380-53
151
495-42
186
610-25
12
39-37
47
154-20
82
269-03
17
383-87
52
498-70
87
613-53
IJ
42-65
48
157-48
83
272-31
18
387-15
53
501 -98
88
616-81
14
45-93
49
160-76
84
275-60
19
390-4!
54
505-26
89
620-09
15
49-21
50
164-04
85
278-88
20
393-71
55
503 -54
90
623-37
1 6
52-49
51
167-33
86
282-16
121
396-99
156
511-82
191
626-65
n
55 -ri
52
170-61
87
285-44
22
400-27
57
515-10
92
629-9J
i8
59-06
53
173-89
88
288-72
23
4=3-55
58
518-38
9!
633-21
19
62-34
54
177-17
89
292-00
24
405-83
59
521-66
94
636-49
20
65-62
55
180-45
90
295-28
25
410-11
60
524-94
95
639-78
21
68-90
56
183-73
91
298-56
126
413-39
161
528-22
196
643-06
22
•;2-i8
57
187-01
92
301-84
27
416-67
62
531-51
97
646-34
2i
75-4^
53
190-29
9!
305-12
28
419 96
63
534-79
98
649-62
24
78-74
59
193-57
94
308-40
29
423-24
64
538-07
99
652-90
25
82 -02
60
196-85
95
311-69
30
426-52
65
541-35
200
656-18
26
85-30
61
200-ij
96
314-97
131
429-80
166
544-63
201
659-46
27
88-53
62
203-42
97
318-25
32
433-08
67
547-91
2
662-74
28
91-87
63
206-70
98
321-53
33
436-36
68
551-19
3
666-02
29
95-15
64
209-98
99
324-81
34
4J9-64
69
554-47
4
669-30
io
98-43
65
213-26
100
328-09
35
442-92
70
557-75
5
672-58
31
101-71
66
216-54
lOI
331-37
U6
446-20
171
561-03
206
675-87
32
104-99
67
219-82
2
334-65
" 37
449-48
72
564-31
7
679-15
J J
I08-27
68
223-10
3
337-93
38
452-76
73
567-60
8
682-4;
34
III-55
69
226-38
4
341-21
39
456-04
74
570-88
9
685-71
35
114-83
70
229-66
5
344-49
43
4;9"33
75
574-16
10
688-99
288
HINTS TO TRAVELLEns.
Tablk XVI. (continued). — Conversiox of MtTUES into English Feet.
211 to 420.
MetrcH
Feet.
Metres
Feet.
Metres
Feet.
Metres
Feet.
Mctreb
Feet.
MetreS|
Feet.
2ll
692-27
246
807-10
28l
021 '93
316
1036-76
351
1151-60
386
1266-43
12
695-55
47
810-38
82
925-21
17
1040-05
52
1154-88
87
1269-71
li
698-83
48
8IJ-66
83
928-49
18
1043-33
53
1158-16
88
1272-99
14
702-11
49
816-94
84
95178
19
1046-61
54
1161-44
89
1276-27
15
705-39
50
820-22
85
935-06
20
1049-89
55
1164-72
90
1279-55
2l6
708-67
251
82J-5I
286
938-34
321
1053-17
356
1168-00
391
I282-8J
17
711-96
52
826-79
87
941-62
22
1056-45
57
1171-28
92
I286-II
l8
715-24
SJ
830-07
88
944-90
23
1059-75
58
1174-56
95
1289-39
19
718-52
54
833-35
89
948-18
24
1063-01
59
1177-84
94
1292-67
20
721-80
55
836 -6}
90
951-46
25
1066-29
60
II8I-I2
95
1295-95
221
725-08
256
839-91
291
954-74
326
1069-57
3C1
1184-40
396
1299-23
22
728-;6
57
845-19
92
958-02
27
1072-85
62
1187-69
97
1302-52
2J
731-64
58
846-47
95
961 -JO
28
1076-13
63
1190-97
98
1305-80
24
734-92
59
849-75
94
964-58
29
1079-42
64
1194-25
99
1309-08
25
738-20
60
853-03
95
967-87
30
1082-70
65
1197-53
400
1312-36
226
741-48
261
856-31
296
971-15
331
1085-98
366
120081
401
1315-64
27
744-76
62
859-60
97
974-45
32
1089-26
67
1204-0)
2
1318-92
28
748-05
63
862-88
98
977-71
a
1092-54
63
1207-37
3
IJ22-20
29
751-33
64
866-16
99
980-99
34
1095-82
69
1210-65
4
1525-48
JO
754-61
65
869-44
300
9S4-27
35
1099-10
70
1213-93
5
1328-76
2JI
757-89
266
872-72
301
987-55
336
1102-38
371
1217-21
406
1352-0;
32
761-17
67
876-00
2
990-83
37
1105-66
72
1220 49
7
1335-33
ii
764-45
68
879-28
3
994-11
38
1108-94
73
1223-78
8
1358-61
34
767-7}
69
882-56
4
997-39
39
1112-22
74
1227-06
9
1341-89
35
77I-OI
70
885-84
5
1000-67
40
1115-51
75
1230 34
10
1345- « 7
236
774-29
271
88912
306
1003-96
341
1118-79
376
1233-62
411
i548-4>
37
777-57
72
892-40
7
1007-24
42
1122-07
77
1236-90
12
I35J-75
38
780-85
75
895-69
8
1010-52
45
1125-35
78
1240-18
13
1355-01
i9
784- 1 J
74
898-97
9
1013-80
44
1128-63
79
1243-46
14
1358-29
40
787-42
75
902-25
10
1017-08
4;
1131-91
80
1246-74
15
1361-57
241
790-70
276
905-53
311
1020- j6
346
113519
3&1
1250-02
416
1364-85
42
795-98
77
908-81
12
1023-64
47
1138-47
82
1253-30
«7
1368-13
45
797-26
78
912-09
13
1026-92
48
1141-75
83
1256-58
18
1371-42
44
800-54
79
915-37
14
1030-20
49
1145-03
84
1259-87
19
1574-70
45
8oj-82
80
918 65
15
1033-48
50
1148-31
«5
1263-15
20
1577-98
TABLES.
289
Table XVI. (continued). — Cunveusiun of Metres into English Feet.
421 to 630.
Metres
Feet.
Metres
Feet.
Metres
Feet.
Metret
Feet.
Metres
Feet.
JMetres
Feet.
421
1^3 1 -26
456
1496-09
491
i6io-92
526
i"25-75
561
1840-58
596
1955-42
22
1^84-54
57
i499-i7
92
1614-20
27
1729-03
62
1845-87
97
1958-70
2}
IJ87-82
58
1502-65
9J
1617-48
28
1732-31
65
1847-15
98
1961-98
24
ii9i-io
59
1505-95
94
1620-76
29
1735-60
64
1850-4}
99
1965-26
25
IJ94'J8
60
1509-21
95
1624-05
io
1738-88
65
1853-71
600
1968-54
426
iJ9r66
461
1512-49
496
1627-33
5JI
1742-16
566
1856-99
601
1971 82
2-
1400-94
62
1515-78
97
i6jo-6i
32
1745-44
67
1860-27
2
1975-10
23
1404-22
6j
1519-06
98
1633-89
JJ
1748-72
68
1863-55
5
1978-38
29
1407-51
64
1522-J4
99
1637-17
54
1752-00
69
1866-83
4
1981-66
JO
1410-79
65
1525-62
500
1640-45
j5
1755-23
70
1870-11
5
1984-94
4>'i
141407
466
1528-90
501
1645 • 7;
556
1758-56
571
1873-39
6o5
1988-22
n
141TJ5
67
I5J2-I3
2
1647-01
37
1761-84
72
1876-67
7
1991-51
a
1420 -6j
68
15^5-46
i
1650-29
38
1765-12
75
1879-95
8
1994-79
J4
I42r9i
69
1558-74
4
1655-57
59
1768-40
74
1883-23
9
1998-07
iS
1427-19
70
1542-02
5
165685
40
1771-69
75
1886-52
10
2001-35
4J6
I4JO-47
471
1 545 'JO
506
1660-13
54 1
1774-97
576
1889-80
611
2004-63
il
I4JJ-75
72
1548-58
7
1663-42
42
1773-25
77
I 893 08
12
2007 91
J8
I4J7-OJ
7}
1551-87
8
1666-70
45
1781-55
78
1896-36
13
2011 19
J9
1440-31
74
1555-15
9
1669-98
44
1784-81
79
1899-64
14
2014-47
40
144? -60
75
1558-4?
10
167J 26
45
1788-09
80
1902-92
15
2017-75
441
1446-88
476
1561-71
5"
1676-54
546
1791-37
58X
1906-20
616
2021 0;
42
i4;oi6
77
1564-99
12
1679-82
47
1794-65
82
1909-48
17
2024- J 1
4?
I45r44
78
1563-27
IJ
1683-10
48
1797-9}
83
1912-76
18
2027 60
44
1456-72
79
I57I-55
14
1686-33
49
i3ol-2i
84
191605
19
2050-88
4?
1460-00
80
1574-8J
15
1689-66
50
1804-49
85
1919-33
20
2054-16
44-5
i4')r28
481
1573-11
516
1692-94
551
1807-78
586
1922-61
621
2057-44
47
1466-56
82
1581-J9
17
1696-22
52
1811-06
87
1925-89
22
2040-72
43
1469-34
8j
1584-67
i3
1699-51
55
1814-34
83
1929-17
25
2044 -cx)
49
i47ri2
84
1587-96
19
1702-79
54
1817-62
89
1952-45
24
2047-28
50
I476'40
85
I59I-2J
20
1706-07
55
1820-90
90
195; -75
25
2050-56
451
1479-69
486
1594-5^
521
1709-35
556
1824-18 591
1959-01
626
2053-84
52
1482-97
87
1597-80
22
1712-63
57
1827-46
92
1942-29
27
2057-12
5J
1436-25
88
i6oi-o3
23
1715-91
58
1830-74
95
1945-57
28
2060-40
54
1489-5}
89
1604-36
24
1719-19
59 1
1834-02 94
1943-85
29
2065-69
55
1492-81
90
1607-64
25
1-22-47
60
1857-50 95
1952-13
50
2066-97
2;jo
iiiN'i's 'lo ti;a\j:li,ki;s.
'r.\r.i,i; XVI. {'■iiiiliiiiriJ). — CoNVKUoioN oi' .ArKTi;ii.s into ]On<;i.i.-ii Kkkt.
631 to 840.
Metres
I'CCt
Metres
1-cot.
Mitres
Feet.
jMi'trtB
I'Cft.
Metres
leet.
Mi Ires
Feet.
Oil
2o;o-i'i
666
2185-0-!
"<"•
2299-9'
7K'
24'4-"4
7v~
2529-57
806
2644-40
r-
207J-5?
67
2188-^6
2
2303-19
37
2418-02
72
2i32-85
7
2647-6-^
ii
2076-81
63
2191-64
3
2306-47
38
2421-50
75
25}fii3
8
2650-97
M
2080-09
69
2194-92
4
2309-75
3')
2424-58
74
2559-42
9
2654-25
iS
2o^j-i7
70
2198-20
5
2313-03
40
2427-87
75
2542-70
10
2657-5}
6?6
2086-65
671
2201-48
706
2316-31
741
2431-15
7-6
2545-98
811
2660-81
31
2o8(j-9J
72
2204-76
7
2319-60
42
2454-4}
"1
2549-26
12
2664 ■o<;
3»
209; -21
73
2208-05
8
2322-88
45
2457-71
78
2552-54
13
2%7-57
iV
2096-49
74
2211-33
9
2326-16
44
2440 -9'j
79
2555-82
14
2670-65
4"
2099-78
75
2214-61
10
2329-44
45
2444-27
80
2559-10
"5
2675-95
641
2IOJ-o6
676
2217-89
711
2332-72
746
2447-55
781
2562-58
816
2677-21
42
2I06-J4
77
2221-17
12
2336-00
47
2450-85
82
2565-66
17
2680-49
4J
2109-62
78
2224-4;
13
2339-28
43
2454-11
85
2568-94
18
2685-78
44
2112-90
79
2227-73
14
2342-56
49
2457-59
84
2572-22
19
2687-06
45
2ii6-i8
80
2251-01
15
2J45-84
50
2460-67
85
2575-51
20
2690-54
646
2119-46
6«i
2234-29
716
2349-12
751
2465-96
786
2578-79
321
2695-62
47
2122-74
82
2237-57
17
2352-40
52
2467-24
87
2582-07
22
2696-90
48
2126-02
8j
2240-85
18
2355-69
5J
2470-52
83
2585-55
25
2700-18
49
2I29-JO
84
2244-13
19
2358-97
54
2475-80
89
2588-63
24
2703-46
50
2IJ2-58
85
2247-42
20
2562-25
55
2477-08
90
2591-91
25
2706-74
651
2135-87
686
2250-70
721
2365-53
756
2480-36
791
2595-19
326
2710-02
52
2i;9-i5
87
2253-98
22
2368-81
57
2485-64
92
2598-47
27
2715-50
5 J
2142-4}
83
2257-26
23
2372-09
58
2486-92
95
2601-75
28
2716-58
54
2145-71
89
2260-54
24
2375-57
59
2490-20
94
2605-03
29
2719-87
55
2148-99
90
2263-32
25
2378-65
60
2495-48
95
2608-31
50
2725-15
656
2152-27
691
2267-10
726
2381-93
761
2496-76
796
2611-60
851
2726-4}
57
2155-55
92
2270-33
27
2385-21
62
2500-05
97
2614-33
52
2729-71
53
2158-83
95
2273-66
28
2388-49
63
2503-35
98
2618-16
55
2752-99
59
2I62-II
94
2276-94
29
2391-78
64
2506-61
99
2621-44
54
2736-27
60
2165-39
95
2280-22
30
2395-06
65
2509-89
8x>
2624-72
55
2759-55
66 1
2168-67
696
2283-51
7JI
2398-34
766
2513-17
831
2628 -co
856
2742-8?
62
2171-96
97
2286-79
32
2401-62
67
2516-45
2
2651-28
57
2746-11
6i
2175-24
93
2290-07
33
2404-90
68
25«9-73
3
2654-56
58
2749-59
64
.2178-52
99
2293-35
3-^
2403-18
69
2523-01
4
2657-84
59
2752-07
65
2i8t-8o
700
2296-63
35
2411-46
70
2526-29
5
2641-12
4=
2:55-9^
'j'AniJos.
291
Tauijo X\'I. {roiitidii'd). — CoNVEUsioN of IMimnos intu Kmjijsu 1'"klt.
841 to 1000,
>Ietrcs>
Feet.
Uilrvb
Feet.
Metres
Feet.
^lctI-e^
Feet.
IMctref
Feet.
1
Metres Feet.
1
841
2759-24
871
2857-66
901
2956-09
926
3038-11
951
3 1 20- 1.
976
3202-16
42
2762-52
7-
2860-94
2
2959-37
27
3041-39
52
3123-42
77
3:05-4 J
4;
2765-80
7}
2864-22
}
2962-65
28
3044-67
55
3126-70
78
3208-72
44
2769-08
74
2867-51
4
2965-93
29
3047-96
54
3129-98
79
' 3212-00
45
2772-36
75
2870-79
5
2969-21
io
3051-24
55
3i;j-26
8o
3215-23
84')
2775-64
876
2874-07
9o5
2972-49
9; I
3354-52
956
3136-54
981 3218-56
41
2778-92
77
2877-35
7
2975-78
32
3057-80
57
3139-82
82 3221-84
43
2782-20
78
2880-63
8
2979-03
i3
30&1-03
53
3 14; -10
83 3225-12
49
2785-48
79
283r9i
9
2982-34
H
3064-36
59
3146-3S
84 3228-40
50
2788-76
80
2887-19
10
2985-62
35
3067-64
60
3149-66
S5 3231-69
851
2792-05
881
2890-47^ 911
2988-90
9;6
3070-92
961
3152-94
936
3234-97
5Z
2795 -JJ
82
2893-75
12
2992-18
il
3074-20
62
3156-22
87
3238-25
5J
2793-61
83
2897-03
IJ
2995-46
38
3077-48
63
3159-51
83
3241-53
54
2801-89
84
2903-31
14
2998-74
39
3080-76
64
3162-79
89
3244-81
55
2805-17
85
2903-60
15
3002-02
40
3084-05
65
3166-07
90
3248-09
856
2808-45
886
2906-88
916
3005-30
941
3087-3;
966
3169-35
991
32=;i-}7
51
23II-7J
87
2910-16
17
3008-53
42
3090-61
67
3172-63
92
3254-65
58
2815-01
88
29U-44
l3
3011-87
45
3093-89
63
3175-91
93
3257-93
59
2818-29
89
2916-72
19
3015-15
44
3097-17
69
3179-19
94
3261-21
(k>
2821-57
90
2920-co
20
3018-4;
45
3100-45
70
3182-47
95
3264-49
861
2824-85
891
2923 ■ 28
921
3021-71
946
3103-73
971
3185-75
996
3267-73
62
2823 •14' 92
2926-56
22
3024-99
47
3107-01
72
3189-03
97
3271-06
6;
28JI-42 9}
2929-84
23
3028-27
4'-
3110-29
73
3192-31
93
3274-34
(H
2834-70 94
2933-12
24
J031-55
40
311J-57
74
3195-60
99
327';-62
65
2837-93 95
1
2936-40
25
5034- 8;
>^
;ii6-3i
7^
5 193 -88
1000
5280-90
86-; 1
2841-26 896
2939-69
67
2844-54 97
2942-97
68
2847-82 98
2946-25
69 1
2851-10 99
2949-53
TO
2854-38 90D
2952 81
X 2
21)2 HINTS 'JO TKAVKI-LKKS.
'I'ai;!,!; X\I[. t'().NVi:u?io\ ok KiLOiiiiXKE.s into English Stati;te JIii.k-
Kilo-
luctrcs.
Euglisli
Statute
Miles.
Kilo-
mctrcs.j
Knglish
Statute
Miles.
Kilo-
metres.'
Kuglish
Statute
Miles.
Kilo-
English
Statute
Miles.
Kilo-
metres,
Kuglibli
Statute
Miles.
0-62
1-24
1-86
2-49
311
3-"J
4-^5
4"97
5-59
6-21
6-84
7-46
8-o8
8-70
9-J2
9-94
10-56
1118
n-8i
I2-4J
62-14
124-28
621 -jS
1242-77
2}
24
25
26
2-
28
2<J
30
a
34
35
J6
37
J8
39
40
J 00
400
3000
4000 I
13-05
4«
ij-67
42
14-29
43
14-91
44
15-53
45
16-16
46
16-78
47
17-50
48
18-02
49
18-64
50
19-26
51
19-88
52
20-51
53
21-13
54
21-75
55
22-37
56
22-99
57
2 J -61
58
24-23
59
24-86
60
186-42
500
248-55
600
1864-15
50C0
2485 53
6ooo
25-48
26-10
26-72
27-34
27-96
28-58
29-21
29-83
30-45
31-07
31-69
32-31
32-93
33-55
34-18
34-90
35-42
36-04
36-66
37-28
310-69
372-83
3106-91
3728-30
72
73
74
75
76
77
78
79
80
700
800
37-90
33-5}
39-15
39-77
40-39
41-01
41-63
42-25
42-88
43-50
44-12
44-74
45-36
45-98
46-60
47-23
47-85
48-47
49-09
49-71
434-97
497-11
7000 I 4349-68
8000 I 4971-06
81
82
83
84
85
86
87
88
89
90
91 •
1
92 j
93 I
94 I
«!
I
96 I
97 1
98
99;
loo
900
1000
50-33
50-95
51-57
52-20
52-82
53-44
54-06
54-68
55-30
55-92
56-55
57*17
57-79
53-41
59-03
59-65
60-27
60-90
61-52
62-14
559-24
6:1 -33
9030 I 5592-44
10,000 6213-82
TABLES.
203
Table XVIII. — Conversion op Ru.s9ian Yersts into English Statute
Miles.
Versts.
English
Statute
Miles.
Versts.
English
Statute
Miles.
Versts.
English
Statute
Miles.
Versts.
English
Statute
Miles.
Versts.
English
Statute
Miles.
I
0-66
21
13-92
41
27-18
61
40-44
8i
53-69
2
i-Ji
22
14-58
42
27-84
62
41-10
82
54-36
3
1-99
23
15-25
4?
28-50
63
41-76
83
55-02
4
2-65
24
15-91
44
29-17
64
42-42
84
55-68
5
i-n
25
16-57
4;
29-83
65
4J-09
85
56-34
6
3-93
26
17-23
46
30-49
66
43-75
86
57-01
1
4-64
27
17-90
47
31-16
67
4441
87
57-67
8
5-jo
• 28
18-56
43
31-82
68
45-08
83
58-33
9
5-97
29
19-22
49
32-48
69
45-74
89
59-00
10
5-6J
io
19-89
50
33-14
70
46-40
90
59-66
II
7-29
31
20-55
51
33-81
71
47-06
91
6032
12
7-9;
32
21-21
52
34-47
72
47-73
92
60-93
IJ
8-62
3 J
21-88
53
35-13
73
48-39
93
61-65
14
9-28
M
22-54
54
35-80
74
49-05
94
62-31
IS
994
35
23-20
5;
36-46
75
49 72
95
6297
i6
io-6i
36
23 86
56
37-12
76
53-38
96
63-64
17
11-27
37
24-53
57
37-78
77
51-04
97
64-30
i8
II-9J
38
25-19
58
38-45
73
51-70
98
64-95
19
12-59
39
25-85
59
39-11
79
52-37
99
65-63
20
ii-26
40
26-52
60
39-77
80
53-03
100
66-29
lOO
66-29
300
198-86
500
231-44
700
464 02
900
596-59
200
132-58
400
265-15
600
397-73
800
550-30
1000
666-88
lOOO
662-88
JOOO
1988-64
5000
3314-39
7000
4640 15
9000
5965-91
2O0O
1325-76
4000
2651-52
6ooo
3977-27
8000
5JOJ-0J
10,000
6628-79
:204 HINTS TO TKA\ Ki,i,i;i;s.
TaUI.E XIX. — Foi! CONVKRTI.VG K ir.OGKAMMES INTO TulXUS A VuMMH TOIS.
Kilogs.l
1
20
JO
4°
50
6o
■73
8o
•ODO 2-205 4'439 6'6i4 8"8i8
22'o46| 24-251 26-455 28-66o io'865
II -02;
j3-o5y
ij-228 I5-6J2 i-;-6j7 19-842
J5"274 i--4'^ J9'68} 41-888
44-092J 46-297 48 502 50-706 52-911 55-116 57-^20 59-525 6i'729 Of
66-1J9, 68-J4? 70-548, 'ii-lSi 74"957j 7ri62
83'i85! 90-^89 92-594 94-799 97-ooj: 99-208
iio*2ji, 112-456 114-640 116-845 119-050 121-254
IJ2-277 U4'482 1^6*686 ij8-89i 141-096^ i4rjoo
I54'i2i 156-528 I58-7JJ i6o-9;7 i6}-i42 165-547
176-570 173-574 180-779' 182-984 185-188 187-59J
I I
1V3-416 2o->C:o 202-825 205-050 207-254 209-459
9?4
79-566 81-571 85-776 85980
101-415 105-617 105-822 108*026
125-54^ 125-665 127-868 150-075
145505 ^"•■Jio 149 9'4 i52««9
167-551 169-556 171-960 174-165
189*597 191-802 194-007 196-211
211-644 215-848 216-055 218-258
f'dinilrif.
Austria ..
|{eli;iiim . .
Canada, etc.
<'liina ..
Donniaik
France . .
Germany
<!re-^c?
Ifollana
India
Italy . .
Norway . .
I'orliigal
liussia ..
.Spain
.Sworten . .
Switzcrlaiul
Turkey . .
United States
T.-vr.i,E XX. — FouEtGX M'ixev.s.
\ViTii lv;ri\ AT.Kxrs IN- J?.':it:.«h Cirijkncv.
/'n'nrlpal Coins.
TOO new kreuzors = i flurin
100 centimes = 1 franc
ICO cents = i dollar . .
1600 — 1700 copper cash = t Haikwan tael
loo Ore = 1 Krone . .
/loo centimes = I franc
(Milliard =: f. 1000 mills. = ^40,000,000.
j North German or Prussian thaler
j South Gern)an florin
j Imperial Rrichsniark =: 100 Pfennigc
( Jni]>erial gold piece of 20 marks . .
100 centimes = I franc
loo cents or 20 stivers = 1 florin . .
192 pie =: 64 pice = 16 anniis = i 11 peo
The lac is ico.ooo jiii>c(s.
loD centcsimi =: i liia
100 Ore =: I Krone . .
loDO Reis = I milrei
100 copecs = I silver rouble
100 centisimos = i peseta =: 4 rcali s
loo ore = I Krone . .
100 rappen or centimes = i franc
ICO piastre = i lira, vat-ialilf
fioo cents = 1 dollar (S) hi ;inhl . .
1 10 dollars =; I e.ijrlo . .
Ster ii.R.
.t. ,1.
4 c
4 ic
9I
1 8
I i
o 9!
tablp:s.
295
Table XXI. — Traverse Table : Difference of Latitude and Departure.
D.
1 1
-'g-
2 Dog.
i Deg.
4 Peg.
5
I leg.
Lat.
Dep.
Lat.
Dep.
Lat.
Dep.
Lat.
Dpp.
Lat.
Dep.
I
oro
00-0
01 -o
oo-o
oi-o
OO-I
OI-O
OO-I
oi-o
co-i
2
02'0
co-o
O2-0
OO-I
02-0
OO-I
02-0
CO- 1
02 -0
00-2
;
oj-o
oo-i
cj-o
00- I
oj -o
00-2
oj-o
00-2
oj-o
OO-J
4
04-0
COT
04-0
OO-I
04-0
00-2
04-0
OO-J
04-0
OO-J
5
05 'O
OO-I
05-0
O0-2
05-0
OO-J
05-0
OO-J
05 -o
004
o6'o
OO-I
o5-o
O0-2
06-0
OO-J
06-0
O0-4
06-0
C0-5
■7
07-0
co-i
07-0
CO- 2
07 'O
00-4
07-0
00-5
07-0
oo'6
8
o8-o
OO-I
08-0
oo-j
08 -o
00-4
08-0
00-6
08 -o
007
9
09-0
00-2
09-0
oo-j
090
00-5
03-0
co-6
09-0
0O-8
lo
IO"0
00-2
lo-o
oo-j
lo-o
00-5
10-0
00-7
lo-o
00-9
2o
20-0
00 3
20-0
00-7
20-0
OI-O
20-0
01-4
19-9
01-7
30
JO'O
00-5
300
01 -o
JO-0
OI-6
29-9
02-I
29-9
02 -6
■40
40 'O
03-7
40-0
01 -4
39-9
02 -I
39-9
02 8
J9-8
0;-;
50
50-0
00-9
50-
01-7
49-9
02-6
49-9
oj-5
49 8
"44
Co
Oo-o
oi-o
6o'o
02-1
59-9
o;-i
59-9
04-2
59-8
oj-2
70
70'o
OI-2
70-0
02-4
69-9
oj-7
69-8
04-9
69- 7
06 -I
80
8o-o
01-4
80-0
02-8
79-9
04-2
79-8
05-6
79 7
07-0
90
90-0
01 -6
. 89-9
oj-i
89-9
04-7
89-8
o6'j
89-7
078
100
IC>0"0
01-7
99 '9
or 5
99-9
05-2
99-8
07-0
996
o3-7
200
200-0
oj-5
199-9
07-0
199 7
IO-5
199-5
14-0
199-2
17-4
ioo
JOO'O
05-2
299-8
lO-J
299-6
15-7
299 -J
209
293-9
26-1
400
J99-9
07-0
J99-8
14-0
m-s
20-9
399-0
27-9
J98-5
34-9
5CX5
499 '9
08-7
499-7
17-5
499-3
26-2
498-8
34'9
498-1
4) -6
600
599'9
10-5
599-6
20-9
599-2
n-4
598-5
41-9
597-7
52-J
700
699-9
12-2
699-6
24-4
C99-0
j6-6
698 -J
48-8
697-3
61-0
803
'!99"9
14-0
799-5
27-9
798-9
41-9
798-1
55-8
797 -0
'. 69-7
900
899-9
15-7
699-5
3'-4
898-8
47-1
897-8
62-8
896-6
78-4
Dep.
Lat.
Dep.
88
Lat.
Deg.
D-.p.
Lat.
Dep.
Lat.
Dep.
Lat.
1).
89
Vg.
87
Dcg.
86
Deg.
85
Dog.
290
HINTS TO TRAVET.T.ERS.
Table XXI. (mntliincd). — Traverse TAiaE: Jh'ffcnncfi of Jjolllude and
Departure
11.
6 r
%■
71
'■f.'-
8 Deg.
9 l^Pg-
10 Deg.
Ut.
Dep.
Lat.
Dep.
Lat.
Dep.
Lat.
Dep.
Lat.
Dep.
I
OfO
oo-i
01 -o
co-i
01 -0
OO'I
01 -o
00-2
01 -0
O0-2
2
02 -o
00-2
02*0
00-2
02 -o
OO'j
02-0
00-3
02-0
00-3
J
oj-o
00 -J
oj-o
00-4
oj-o
00-4
Oi-o
O0-5
03-0
00-5
4
04-0
00-4
04-0
00-5
04-0
00-6
04-0
00-6
03-9
C0-7
5
o;-o
00-5
05-0
00-6
05-0
00-7
04-9
00-8
04-9
00-9
6
06 -0
00-6
o6-o
00-7
05-9
00-8
05-9
oo"9
05-9
OI-O
7
o';-o
00-7
06-9
00-9
06-9
oi-o
06-9
01 -I
06-9
01-2
8
o8-o
00-8
07-9
01 -o
07-9
01 -I
07-9
01-3
07-9
01-4
9
09-0
oo'9
089
01 -I
08-9
01 -J
08-9
01-4
08-9
01-6
10
09-9
oi-o
09-9
01 -2
09-9
01-4
09-9
01-6
09-8
01-7
20
19-9
02-I
19-9
02-4
19-8
02-8
19-8
03-1
19-7
03-5
lo
29-8
oj-l
29-8
or 7
29-7
04-2
29-6
04-7
29-5
05-2
40
jy8
04-2
39-7
04-9
i9-6
05-6
39-5
06-3
J9'4
06-9
50
49-7
05-2
49-6
o6-i
49*5
07-0
49-4
07-8
49-2
08-7
60
59-7
06-J
59-6
07-J
59-4
08-4
59- J
09-4
59-1
IO-4
'0
69-6
ovi
69-5
08-5
69-^
09-7
69-1
ii-o
68-9
12-2
80
79-6
08-4
79-4
09-7
79-2
II-I
79 "o
12-5
78-8
13-9
93
89-5
09-4
89- J
li-o
89-1
12-5
88-9
14-1
88-6
156
I DO
99-;
10-5
99-i
12-2
99-0
ir9
988
15-6
98-5
174
200
198-9
20-9
198-5
24-4
198-1
27-8
197-5
iI-3
197
in
JOO
298-4
Ji-4
297-8
^6-6
297-1
41-8
296-3
46-9
295-4
52-1
400
J97-8
41-8
397 '0
48-7
396-1
55-7
J95-I
62-6
i9r9
69-5
;co
497 -J
52-j
496 -i
60-9
495-1
69-6
493-8
78-2
492 -4
86-8
6oo
596-7
62"7
595 "5
7?!
594- '•«
8}-5
592-6
9J-9
593-9
104-2
■joo
696-2
7r2
694-8
85-J
69}- 2
97-4
691-4
109-5
689 4
121-6
800
795-6
8j-6
794-0
97-5
792-2
iii-j
790-2
125-1
787-8
138-9
900
895-1
94-1
89J-i
109-7
891-2
ii$-i
888-9
140-8
886-3
156-3
n.
Dep.
Lat.
Dep.
Lat.
Dep.
Lat.
Dep.
Lat.
Dep.
Lat.
84 I
)eg.
8jl
leg.
82 Deg.
81 I
>eg.
80 I
)eg.
TABLES.
21^7
Table XXI. (continued). — Traverse Table : Difference of Latitude and
Departure.
D.
II
Deg.
12
Dor.
ij
Deg.
14 Deg.
I? Deg.
Lat.
Dep.
Lat.
Dep.
Lat.
Dep.
Lat.
Dep.
Lat.
Dep.
I
OfO
00-2
oi-o
00-2
01 -0
00-2
OI-O
00-2
OI-O
ao-i
2
02 -o
00-4
02-0
00 "4
01-9
00-4
01-9
00-5
CI -9
00-5
J
02-9
00-6
02-9
00-6
02-9
00-7
02-9
00 7
02-9
00-8
4
oi-9
00-8
0J-9
0O-8
oi-9
00-9
0J-9
OI-O
oj-9
OI-O
5
04-9
oi-o
04-9
OI-O
04-9
01 I
04-9
01 2
04-8
oi-j
6
05-9
oi-i
05-9
OI-2
05-8
oi-i
05-8
01-5
05-8
01-6
7
06 9
oi-i
o6-8
01-5
o6-8
01-6
06-8
01 7
068
01-8
8
07-9
01-5
07-8
OI-7
07-8
01-8
07-8
OI-9
07-7
02 I
9
088
01-7
o8-8
01-9
08-8
02 -o
o3-7
02 -2
08-7
02-j
lO
09-8
01-9
09-8
02-1
09-7
02-2
09-7
.02-4
09-7
02-6
20
19-6
oj-8
19-6
04-2
19-5
04-5
19-4
04-8
I9-J
C5-2
JO
29-4
05-7
29-J
06-2
29-2
06-7
29-1
o7-i
39-0
0--8
40
in
07-6
39-1
08-j
J9-0
09-0
j3-8
09-7
j3-6
10-4
50
49-1
09-5
48-9
10-4
48-7
11-2
48-5
12-1
48-J
12-9
6o
58-9
11-4
58-7
12-5
58-5
IJ -5
58-2
14-5
58-0
15-5
•JO
68-7
ir4
68-5
14-6
68-2
15-7
67-9
16-9
67-6
18-1
8o
78-5
in
78-j
16-6
77-9
18-0
77-6
19-4
m
20-7
90
88-j
17-2
88-0
18-7
87-7
20-2
8tj
21-8
86-9
2;-?
100
98-2
19-1
97-8
20-8
97-4
22-5
97-0
24-2
96-6
25-9
20D
196 -J
J8-2
195-6
41-6
194-9
45 -o
194-1
48-4
195-2
51-8
JOZ,
294-5
57-2
291-4
62-4
292 -J
67-5
291-1
72-6
289-8
77-6
400
J92-7
76-J
391 -J
8J-2
J89-7
90-0
J88-1
96-8
J86-4
ior5
500
4<;o-8
95-4
489-1
io4'o
487-2
112-5
485-1
121-0
48J-0
129-4
600
589-0
114-5
586-9
124-7
584-6
IJ5-0
582-2
145-2
579-6
J55-J
700
687-1
ijj-6
684-7
145-5
682-1
157-5
679-2
169- J
676-1
181-2
800
785 -J
152-6
782-5
l66-i
779-5
180-0
776-2
193-5
772-7
207-1
900
m-i
171-7
880 -J
187-1
876-9
202-5
87rj
217-7
869 j
2J2-9
Pep.
Lat.
Dep.
Lat.
Dep.
Lat.
Dep.
Lat.
Dep.
Lat.
n.
79 1
let;.
78 r
)eg.
77 T
>?.
76 T
)eg.
75 I
)pg.
298
HINTS IT) TltAVEIJ-KHS.
T.\i5i,i: XXr. (c()ulhii(e(l).-~'i\i\VEiiS]i Table: Difference of Lntiltule nnd
Departure.
T).
16 llOK.
17
lot;.
i3
>rg.
19 I>tg.
20 Deg.
L.it.
Dcp.
Lat.
Dcp.
Lat.
Dep.
ut7
Dep.
Lat.
Dep.
I
01 'O
oo-j
OI-Q
00-J
oi-o
oo-j
00-9
oo-j
00-9
OO-J
2
01 9
00-6
01-9
00-6
019
00-6
01-9
00-7
01-9
00-7
3
02-9
co-8
02-9
00-9
02-9
00-9
02-3
oi-o
02 -8
OI-O
4
c;-8
01 I
oj-8
01-2
oj-3
01-2
oj-8
01 -j
oj-8
01-4
5
04-8
01-4
04-8
01-5
04-3
ci-5
04-7
01-6
04-7
01-7
6
05-8
01-7
05-7
OI-3
05-7
01-9
05-7
02-0
05 6
02-1
7
o6'7
01-9
06-7
02-0
06-7
02-2
06-6
02- J
o6-6
02-4
8
07-7
02-2
07-7
02-;
07-6
02-5
07-6
02-6
07-5
02-7
9
08-7
02-5
o3-6
02-6
08-6
02-8
08-5
02-9
o3-5
OJ-I
lO
09-6
02-8 •
09-6
02-9
09-5
oj-i
09-5
033
09-4
03 -4
20
19-2
05-5
19-1
05-8
19-0
06-2
18-9
05-5
18-8
06-3
JO
28-8
oZ-i
28-7
08-8
28-5
09-3
28-4
09-8
28-2
lo-j
40
J8-5
li-o
38 -J
II-7
j8o
12-4
37-8
ij-o
37-6
iJ-7
50
48-1"
irs
47-8
14-6
47-6
15-5
47-3
16-J
47-0
171
60
57-7
16-5
57-4
I7'5
57-1
13-5
56-7
19-5
56-4
20-5
'0
67-;
19- J
66-9
20-5
66-6
21-6
66-2
22-8
65-8
2J-9
80
76-9
22-1
765
23-4
76-1
24-7
75-6
26-0
75-2
27-4
qo
86-5
24-8
86-1
26-j
85-6
27-8
85-1
29-3
84-6
jo-8
100
96-1
27-6
95-6
29-2
95-1
30-9
94-6
32-6
94-0
34-2
200
192 -J
5;- 1
191 J
58-5
190-2
6i-8
189-1
65-1
187-9
68-4
JOO
288-4
82-7
286-9
87-7
285-3
92-7
28} -7
97-7
281-9
102 -6
400
384-5
iio-j
382-5
ii6-g
380-4
I2!-6
378-2
IJO-2
375-9
ij6 8
500
480-6
IJ7-8
478-2
146-2
475-5
1 54 -5
472-8
162-8
469-8
171-0
600
576-8
165-4
573-8
175-4
570-6
185-4
567-3
195-3
563-8
205 -2
•;oo
672-9
192 9
669-4
204-7
665-7
216-J
661-9
227-9
657-8
239-4
800
769-0
220-5
765-0
233-9
760-8
247-2
756-4
260-5
751-8
273-6
900
865-1
248-1
860-7
263 1
856-0
278-1
851-0
293-0
845-7
307-8
1)
Dep.
74
Lat.
Dcp.
Lat.
Dep.
7: I
L,t.
Dep.
71 1
Lat.
Dop.
7= I
Lat.
'-, l>>\i;'.
i.p.
TABLES.
2!)9
Table XXI. (roi(fiimed). — Tkaverse Table: Difference of Latiiude and
Departure.
D.
21 Dog.
22
Deg.
23 Deg.
Lat. Dep.
24 Deg.
25 Deg.
Lat.
Dep.
Lat.
Dep.
Lat.
Dtp.
Lat.
l;ep.
I
oo'9
00-4
00-9
00-4
00-9
00-4
00-9
00-4
00-9
00-4
2
01-9
00-7
01-9
00-7
01-8
00-8
01-8
00-8
01-8
00-8
J
02-8
01 -I
02-8
i oi-l
02-8
01-2
02-7
01-2
02-7
01-3
4
oy]
01-4
oj-7
01-5
03-7
01-6
C3-7
01-6
03-6
01-7
5
04-7
01-8
04-6
01-9
04-6
02-0
04-6
02-0
04-5
02 -I
6
05-6
02 -2
05'6
02-2
05-5
02-3
05-5
02-4
05-4
02-5
7
05-5
02 -5
06-5
02-6
06-4
02-7
06-4
02-8
o6-3
03-0
3
07-5
02-9
OT4
oj-o
07-4
03-1
07-3
0; • 3
07-3
03-4
9
08-4
OJ-2
08 -J
oj-4
08-3
o;-5
08-2
03-7
o3-2
oj-8
lO
on
or6
09 -J
, oj-7
09-2
or9
05- 1
04-1
o)-i
04-2
20
ri-)
07-2
13-5
07-5
13-4
07-8
18-3
08 • I
l8-l
08-5
jO
28-0
10-8
27-8
11-2
27-6
II-7
27-4
12-2
27-2
12-7
4^
m
14 -J
i-i
15-0
36-8
15-6
j6-5
16 -3
j6-?
16 -9
50
4f,-7
17-9
46-4
18-7
46-0
19-5
45-7
20-3
45-5
2I-I
6o
56-0
21-5
55-6
22-5
55-2
23 -4
54-8
24-4
54'4
25-4
■]o
65-4
25-1
64-9
26-2
64-4
27-4
63-9
28-5
63-4
29-6
8o
74-7
28-7
74-2
30-0
7J-6
31-3
73-1
32-5
72-5
33-3
<jo
84-0
n-1
8J-4
3J-7
82-8
35-2
82-2
36-6
81 -6
38-0
loo
9J'4
J5-8
92-7
37 5
92-1
39-1
91-4
40-7
90-6
42-3
200
186-7
71-7
185-4
74-9
184-1
78-1
182-7
81-3
181-3
84-5
300
280-1
107-5
278-2
112-4
276-2
117-2
274-1
I22-0
271-9
126-8
403
J7r4
i4r3
J70-9
149-8
368-2
156-3
365-4
162-7
362-;
169-0
50D
466-8
179-2
465-6
187-3
460-3
195 '4
456-8
20; -4
453-2
2II-3
6oo
560-1
215-0
556 -i
224-8
S-^r-i
2i4-4
548-1
244-0
54? -8
253-6
■JOO
65r5
250-9
649-0
262-2
644-4
27r5
639-5
284-7
634-4
295-8
8oo
746-9
286-7
741-7
299-7
736-4
312-6
430-3
325-4
725-0
338-1
9DO
840-2
J22-5
8M-5
337-1
828-5
351-7
822-2
366-1
815-7
380-4
Hop.
Lat.
Dep.
Lat.
Pep.
67 r
Lat.
)eg.
Dep.
Lat.
Dep.
Lat.
n.
^9 1
)cg.
(,?. 1 loy:.
66 r
>.tc.
'''o-
300
HINTS TO TRAYEIJ.KHS.
Table XXI. (continued). — Travkrse Tarlk : Difference of Latitude and
Departure.
D.
26 ])eg.
27 Deg.
28 Deg.
29 Deg.
30 Deg.
Lat.
Dep.
Lat.
Dep.
Lat.
Dep.
Lat. '
1
Dep.
Lat.
rep.
I
00-9
00-4
00-9
00-5
00-9
0O-5
00-9
005
009
0O-5
2
of8
00-9
01-8
C0-9
01 -8
00-9
01-7
01 -o
01-7
oi-o
i
02-'7
oi-j
02-7
01-4
02-6
01 -4
02-6
01-5
o2"6
01-5
4
oi-6
01 -8
oj-6
01-8
oi-5
01-9
03-5
01-9
03 -5
02 -o
5
04-5
02 -2
04-5
02-j
04-4
02-3
04-4
o2'4
.04-3
02-5
6
05-4
02-6
05-j
02-7
05-3
02-8
05-2
02-9
05-2
oj-o
7
o6-j
oj-i
06-2
or2
o6-2
OJi
06-1
03-4
06 I
03-5
8
07-2
oj-5
07-1
oj-6
07-1
o}-8
07-0
03-9
o6"9
04-0
9
o8-l
oj-9
08-0
04-1
0T9
04-2
07-9
04-4
07 8
04-5
lo
090
04-4
08-9
04-5
o8'8
04-7
08-7
04-8
08-7
05*0
20
i8-o
08-8
17-8
09-1
17-7
09-4
17-5
09-7
17-3
lo-o
JO
2T0
Ii-2
26-7
ir6
265
14-1
26-2
145
26-0
I5-0
40
j6*o
17-5
J5-6
18-2
3S-}
i8-8
35-0
19-4
34-6
20-0
5°
44-9
21-9
44-6
22-7
44-1
2}-;
43-7
24-2
43-3
25-0
6o
5r9
26-i
5r5
27-2
5ro
28-2
52-5
29-1
52-0
30-0
-o
62*9
io■^
62-4
31-8
61-8
32-9
6i-2
33-9
60-6
35 -o
8o
■;i-9
J5'i
7I-J
36-3
70-6
37-6
70-0
j8-8
693
40-0
90
80-9
irs
80-2
40-9
79-5
42-3
78-7
43 -6
77-9
45 -0
lOO
89-9
4r8
89-1
454
88-j
46-9
87-5
48-5
86-6
50-0
200
179-8
87-7
1-8-2
90-8
176-6
939
174-9
97-0
173-2
100
JOO
269-6
iii-5
267 -J
Ij6-2
264-9
140-8
262-4
145-4
259-8
150-0
400
J59-5
I75-J
356-4
i8i-6
355-2
187-8
349-8
193-9
346-4
200-0
500
449"4
2iq-2
445-5
227-0
441-5
: 234-7
437-3
242-4
433 -o
250*0
600
5J9"i
26J-0
5J4-6
272-4
529-8
281-7
524-8
290-9
519-6
300-0
700
629-2
306-9
62J-7
JI7-8
618-1
328-6
612-2
359-4
6o6-2
350-0
8oo
719-0
iio■^
712-8
363-2
706-4
3756
699-7
387-8
692-8
400-0
900
808-9
394-5
801-9
408-6
W7
422-5
787 -2
436-3
7-9-4
450-0
D.
Dep.
Lat.
Dep.
Lat.
Dep.
! Lat.
Dep.
Lat.
Dep.
Lat.
64 I
")efr.
fji 1
:>eg.
62
Peg.
61 1
'eg.
60I
")pg.
TABLES.
301
Table XXI. (roiiliimeil). — Tkavkksk Taule : Difference of LaiHwle and
Departure.
D.
31
Ag.
J2
Deg.
}}
)eg.
M
[Jeg.
;f I'tir.
Lat.
Dcp.
Lat.
Dep.
Lat.
Dep.
Lat.
J)ep.
Lat.
L'cp.
I
oo'9
co-5
00-8
oc-5
co-8
00-5
00-8
00-6
00-8
00-6
2
OI-7
01 -o
01 -7
01 -I
01-7
ot-i
01-7
01 -I
01 -6
01 -I
}
02-6
01 -5
02-5
01 -6
02-5
OI-6
02-5
01-7
02-5
01-7
4
or 4
02 -I
or 4
02-1
03-4
02-2
03-3
02-2
03-3
02-3
5
04 -J
02-6
04-2
02-6
04-2
02-7
04-1
02-8
04-1
02-9
6
05-1
OJ-I
05-1
or2
05-0
03-3
05-0
03-4
04-9
or4
7
oi-o
oj-6
05-9
or7
o;-9
03-8
05-8
03-9
o;-7
04-0
8
06-9
04-1
06 -8
04-2
0O-7
04-4
06-6
04-5
o5-6
04-6
9
07-7
04-6
07-6
04-8
07-5
04-9
07-5
05-0
07-4
05-2
10
o3-6
05-2
08-5
05 -i
08-4
05-4
o8-;
05-6
o3-2
05-7
20
'"■I
10- j
17-0
10-6
16-8
10-9
16-6
11-2
i5-4
11-5
}o
25-7
15-5
25-4
15-9
25-2
16-3
24-9
16-8
24-6
17-2
40
Hi
20-6
3r9
21-2
n-;
21-8
3J-2
22-4
32-8
22-9
53
42-9
25-8
42-4
26-5
41-9
27-2
41-5
28-0
41-0
28-7
60
51-4
30-9
50-9
31-8
50-3
32-7
49-7
33-6
49-1
34-4
70
6o-o
36-1
59-4
37-1
58-7
38-1
58-0
39-1
57-J
43-2
80
63-6
41-2
67-8
42-4
67-1
4r6
66-3
44-7
65-5
45-9
90
77-1
46-4
76-j
4r7
'5'}
49-0
74-6
50-3
7i-7
51-6
I03
8,-7
51-5
84-8
5ro
83-9
54-5
82-9
55-9
81-9
-7-4
200
171-4
lOJ-O
169-6
io6-o
167-7
108-9
165-8
111-8
i6{-8
114-7
,'03
257-2
154-5
254-4
159-0
251-6
163-4
248-7
167-8
245-7
1721
400
i42-9
206 -o
JJJ9-2
212-0
ass
217-9
331-6
223-7
327-7
229-4
500
428-6
25r5
424-0
265-0
419-i
272-3
414-5
279-6
409-6
286-8
600
5I4-J
J09-0
508-8
318-0
503-2
326-8
497-4
JJ5-5
491 -s
i44-i
•joo
6oo-o
360-5
595-6
370-9
587-1
381-2
580-3
591-4
57r4
401-5
«oo
68,-7
412-0
678-4
4Zi-9
670-9
4J5-7
663-2
447-4
655-3
458-9
.;oo
■/-I-5
46J-S
763-2
476-9
754-8
490-2
746-1
503 -3
737-2
516-2
D.
Dep.
Lat.
Dep.
Lat.
Dap.
Lat.
Dp.
Lat.
Dep.
Lat.
59 t
eg-
58 r
eg.
57 r
eg-
56 D
eg.
55 r
'eg.
:50ii
HINTS TO TJ{A\'I;M,K US.
Tadi.k X.XI. (rii)///////r,/). -'I'uaveksi'; TAiii,i;: J)il)'fnnrr nf JtnlHniU mid
n.
l,i(. Dp.
;7
iK-p.
3a
>ig.
39
.,.g.
4-
"■g.
Lat.
Hep.
Lat.
iJcp.
Dp.
I
03-8
00 -6
OT-3
00-6
co-8
co-6
00-8
00-6
00-8
00-6
2
01 -6
01-2
CI -6
01-2
01-6
01-2
01-6
01 -3
01-5
01-3
j
o:-4
• OI-8
02 -4
01-8
02-4
01-8
02-3
01-9
02 -3
Of 9
4
oj • 2
02-4
OJ-2
02-4
03-2
02-5
03-1
02-5
o;-i
02-6
5
04-0
02-9
04-0
o;-o
03-9
03-1
03 -9
03-1
oj-8
03-2
6
04-9
f>r5
04-8
o;-6
04-7
03-7
04-7
03-8
04-6
03-9
7
oi-v
04-1
05-6
04-2
05-5
04-3
05-4
04-4
05-4
04-5
8
c6-5
04-7
o5-4
04-8
o5-3
04 9
o6-2
05-0
06-1
05-1
9
o"-J
05-3
07-2
05-4
07-1
05-5
07-0
05-7
06-9
05-8
lO
of. -I
05-9
o3-o
oO-o
07-9
06-2
07-8
o'n
07-7
o6-4
20
16 -2
11-8
i6-o
120
15-8
12-3
15-5
12-6
15-3
12-9
JO
24-j
17-6
24-0
18-1
23-6
18-5
23-3
189
23-0
19-}
4°
32-4
2j-5
JI-9
24-1
31-5
246
311
25-2
30-6
25-7
50
40-5
29-4
39-9
30-I
39-4
30-8
33-9
31-5
38-3
321
6o
48-5
35J
4"-9
36-1
47-3
36-9
46-6
37-8
46-0
33-6
■JO
56-6
41-1
5; -9
42-1
55-2
43-1
54-4
44-1
5; -6
45-0
8o
64-7
47-0
63-9
48-1
63-0
49-3
62-2
50-3
61-3
5'-4
")0
72-8
52-9
71-9
54-2
70-9
55-4
69-9
56-6
68-9
57-9
lOO
80-9
58-8
wg
60-2
73-8
61-6
77-7
629
76-6
64-3
2CO
i6i-8
117-6
159-7
120-4
157-6
123-1
155-4
125-9
151-2
128-6
JOO
242-7
176-3
239-6
180-5
236-4
184-7
233 I
188-8
2:9-8
192-8
400
ni-(>
23; -I
319-5
240-7
315-2
24'>-3
310-9
251-7
3o'v4
257-1
500
404-5
293-9
399-3
300-9
394-0
307-8
388-6
314-7
383-0
321-4
60 D
48,-4
i52"7
479-2
361 -I
472-8
369-4
466-3
377-6
459-6
385-7
7 CO
566-3
411-4
559-0
421-3
551-6
4310
544-0
440-5
5J5-2
450-0
8oo
647-2
470-2
638 -9
481-5
630-4
492-5
621-7
503-5
612-8
514-2
900
728-1
529-0
718-8
541-6
709-2
554-1
699-4
566-4
639-4
578-5
D?p.
Lat.
D.p.
L:U.
Dep.
Lat.
Dop.
Lat.
Dep.
Lat
i).
■
54 1
X^2.
53 1
> K-
;: [
),.m;_
;i 1
' -•
5? I
)eg.
TABLKS.
303
TA!ii,i; XXI. {fnuliiiiiiil). — TiJAVKKSK Tai;!,!; : Diffciium nf Liditiiiln end
J)l [KlliHl' .
1).
41 l'"g.
42 Deg.
4 J Ueg.
44 l^«o'-
45 Lieg.
Lat.
I)?l>.
Lat.
Dep.
Lat.
Dep.
Lat.
Dep.
Lat.
Dep.
I
O0-3
00-7
00-7
00-7
00-7
OD-7
00-7
00-7
O0-7
00-7
2
01 -5
01 -J
01-5
oi-i
CI -5
01-4
01-4
CI 4
01-4
CI -4
3
oi-j
02-0
02-2
02-0
02-2
02-0
02-2
02 I
02-1
02-1
4
Oi'O
02-6
03-0
02-7
02-9
02-7
02-9
02-3
02-8
02-8
5
o;-8
o}-}
oj-7
oj-j
03 ■ 7
03-4
03-6
03-5
03-5
o;-5
6
04-5
0J-9
04-5
04-0
04-4
04-1
04-3
04-2
04-2
04-2
7
05-J-
04-6
05-2
04-7
05-1
04-8
05-0
04-9
04-9
04-9
8
o5"o
05-2
05-9
05-4
C5-9
05-5
05-8
05 -6
05-7
05-7
y
o6-8
05-9
0G-7
06-0
o')-6
06-1
06-5
06-3
06-4
0^.-4
lO
o7*5
06 -6
07 4
06-7
07-j
06-8
07-2
05-9
07-1
07-1 -
20
15-1
ij-i
14-9
ir4
14-6
13-6
14-4
13-9
I4-I
14-1
^o
22-6
iy-7
22-j
20-1
21-9
20-5
21-6
20-3
21-2
21-2
4^
30-2
26-2
29-7
26-8
29-j
27-3
28-8
27-3
23-3
28-3
50
i7-7
J2-8
J7-2
irj
36-6
34-1
36-0
34-7
35-4
35-4
6o
45-3
39-4
446
40-1
45-9
40-9
45-2
41-7
4--4
42-4
'O
52-8
45-9
52-0
46-8
51-2
47-7
50-4
48-6
49-5
49-5
8o
60-4
52-5
59-5
53-5
58-5
54-6
57-5
55-6
56-6
50-6
<P
67-9
59-0
66-9
60-2
65-8
61 -4
64-7
62-5
63-6
63-6
1C<3
7i'5
65-6
74- i
66-9
'J-i
68-2
71-9
69-5
70-7
70-7
loo
150-9
i;i-2
148-6
liJ-8
146-3
136-4
MJ-y
138-9
141-4
141-4
JOO
226-4
196-8
222 9
200-7
219-4
204-6
215-8
2o3-4
2I2-I
212-1
400
joi-9
262-4
297 -J
267-7
292-5
272-8
287-7
277-9
282-8
282-8
P3
rrr-i
J28-0
371-6
3}rf>
365-7
34t-o
359-7
347-3
35 J -6
353-6
God
452-8
}<);■(>
445-9
401-5
4J8-8
409-2
4?i-6
416-8
424-3
42-1-3
700
528-i
459-2
520-2
468-4
511-9
477-4
503-5
486-3
495-0
495 -o
803
60; -3
524-8
594-5
5J5-J
535-1
545-6
575-5
555-7
565-7
565-7
goo
679-2
590-5
668-8
602-2
653-2
613-8
647-4
625-2
636-4
636-4
D.
D.p.
Lat.
Dep.
Laf.
Dep.
47 I
Lat.
Dep.
Lat.
D-p-
Lat.
49 E
e,.
431
)sg.
46 I
)ii.
45 I
eg.
304
HINTS TO I'KAVKLLERS.
Tablk XXII. — Natural Sinks, Tangents, Secants. et<
l)eg.
1 ^.
Sine.
Cosec.
Tan.
Cotaii.
Sf<:ai,t.
Co.-iii.
o
o-oo
infinite.
o-oo
infinite.
I-OOOOO
1-00000
90
I
0-0174;
57-2986
0-01745
57-2899
I -00015
0-99984
89
2
o-o;489
28-6537
0-03492
28-6362
1 -00060
0-99939
88
J
o-o52i?
19-107J
0-05240
19-0811
I -00157
0-99862
87
4
0-06975
i4-»5;
0-06992
14-3006
1-00244
0-99756
86
?
o-o87i;
II-47J7
0-08748
H-4J03
1-00381
0-99619
85
6
0-10452
9-5667
0-10510
9-5m
1-00550
0-99452
84
1
0-12186
8-2055
0-12278
8- 144 J
1-00750
0-99254
83
8
0-U917
7-1852
0-14054
7-115}
1-00982
0-99026
82
9
o-i?64}
0-17364
6-3924
0-15838
6-3137
I -01246
0-98768
Rl
10
5-7587
0-17632
5-6712
1-01542
0-98480
80
II
0-19080
5-2408
0-19438
5-1445
1-01871
0-98162
79
12
0-20791
4-8097
0-21255
4-7046
I -02234
0-97814
78
IJ
0-22495
4-4454
0-23086
4-3JI4
1-02630
Q-974J7
77
14
0-24192
4i»5
0-24932
4-0107
1-OJ06I
0-97029
•J6
If
0-25881
3-8637
0-26794
3-7J20
1-03527
0-96592
75
16
0-2756J
3-6279
0-28674
3-4874
1-04029
0-96126
74
17
0-29237
3-4203
0-30573
3-2708
1-04569
0-95630
73
18
0-J0901
3-2360
0-32491
3-0776
1-05146
0-95105
72
19
■ 0-32556
3-0715
o-344?2
0-36397
2-9042
1-05762
0-94551
71
20
0-34202
2-9238
2-7474
I -06417
0-95969
7o
21
0-35836
2-7904
0-38386
2-6050
1-07114
0-9JJ58
69
22
0-37460
2-6694
0-40402
2-4750
1-0785}
0-92781
68
2}
0-39073
2-559J
0-42447
2-3558
I -08636
0-92059
67
24
0-40673
2-4585
0-4^522
0-46630
2-2460
I -09463
0-91354
66
25
0-42261
2-3662
2-1445
1-10337
0-90630
65
26
0-43837
2-2811
0-48773
2-0503
I-II260
0-89879
64
27
0-45399
2-2026
0-50952
1-9626
I-I2232
0-89100
63
28
0-46947
2-1300
0-53170
1-8807
I-I3257
0-88294
62
29
0-48480
2-0626
0-55430
I • 8040
J-I4J35
0-87461
61
30
0-50030
2-0300
0-57735
1-7320
1-15470
0-86602
• 60
31
0-51503
I -9416
0-60086
1-6642
1-16663
0-85716
59
J2
0-52991
1-8870
0-62486
1-6003
1-17917
0-84804
58
JJ
0-54463
1-8360
0-64940
1-5398
I -19236
0-83867
57
^4
0-55919
1-7882
0-67450
1-4825
I -20621
O'829o}
56
ii
0-57J57
I-74J4
0-70020
I -4281
1-22077
0-81915
55
J6
0-58778
1-7013
0-72654
1-3763
1-23606
0-80901
54
J 7
o-6oi8l
I -6616
0-75J55
1-3270
1-25213
0-79863
5J
J8
0-61566
1-6242
0-78128
1-2799
I - 26<pi
0-78801
52
i9
0-62952
1-5890
0-80978
1-2348
1-28675
0-77714
51
40
0-64278
1-5557
0-83909
1-1917
1-30540
0-76604
50
41
o-6;6o5
1-5242
0-86928
1-1503
1-32501
0-75470
49
42
0-66913
1-4944
0-90040
1-1106
I-J4563
0-74314
48
4J
0-68199
1-4662
0-93251
1-0723
1-36732
0-73135
47
44
0-69465
•-4595
0-96568
1-OJ55
I -39016
0-71953
46
45
0-70710
1-4142
1-00300
I -OODO
I-4I42I
0-70710
45
1 CosiE.
Secant.
Cotan.
Tan.
Cosoc. j
Sine.
Deg.
TABLES.
305
Table XXIII.
T' = A
pprox.
B =
Mean
OF Secoot) Differences.
Lonf
j
Time.
im
2"
jm
4-
5m
6m
,m
8m
9m
lom iim
12m
H. M.
H. M.
"
"
"
II
II
~~7"
'^
"
II
II
"
"
0. o
12.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
O.IO
II-50
0.4
0.8
1.2
1.6
2.1
2.5
2.9
3.3
3.7
4.1
4-5
4.9
0.20
ir.40
0.8
1.6
2.4
J. 2
4.1
4-9
5-7
6.5
7-3
8.1
8.9
9-7
o.^o
II. io
1.2
2.4
}.e
4.8
6.0
7-2
8.4
9.6
10.8
12.0
IJ.2
14.4
0.40
11.20
1.6
J.I
4-7
6. J
7-9
9-4
II.
12.6
14.2
15.7
17-3
18.9
0.50
II. 10
1-9
3-9
5.8
7.8
9-7
II. 6
IJ.6
15.5
17.4
19.4
21. J
23.3
1.
II.
2. J
4.6
6.9
9.2
11.5
ii-7
16.0
18. J
20.6
22.9
25.2
27-5
1. 10
10.50
2.6
5-3
7-9
10.5
IJ.2
15.8
18.4
21. 1
2J.7
26.J
29.0 J1.6
1.20
10.40
J.O
5-9
8.9
11.9
14.8
17.8
20.7
2J.7
26.7
29.6
J2.6
J5.6
l.io
10. JO
}.}
6.6
9.8
13.1
16.4
19.7
2J.O
26.2
29.5
J2.8
j6.i
39-4
1.40
10.20
J.6
7-2
10.8
14.4
17.9
21.5
25.1
28.7
32.J
35-9
39-5
43-1
1.50
10.10
}-9
7.8
11.6
15.5
19.4
2J.J
27.2
JI.I
34-9
j8.8
42.7
46.6
2.
10.
4.2
8. J
12.5
16.7
20.8
25.0
29.2
3!. 3
37-5
41.7
45.8
50.0
2.10
9.50
4.4
8.9
I}. 3
17.8
22.2
26.6
il.I
3S-S
39.9
44.4
48.8
53.J
2.20
9.40
4-7
9.4
14. 1
18.8
2i-S
28.2
32.9
31.6
42.3
47-0
51.7
56.4
2.iO
9.30
4-9
9.9
14.8
19.8
24.7
29.7
M-6
39-6
44-5
49-5
54-4
59-4
2.40
9.20
5-2
10.4
15.6
20.7
25.9
JI.I
J6.j
41. 5
46.7
51.9 57.0
62.2
2.50
9.10
5-4
10.8
16.2
21.6
27.1
32.5
31-9
4J.3
48.7
54.1 49.5 64.9
}.
9.
5.6
II. 2
16.9
22.5
28.1
JJ-7
39-i
45.0
50.6
56.2 61.9 67.5
MO
8.50
5.8
II. 7
17-5
2J.J
29.1
J5.0
40.8
46.6
52.4
53. J 64.1
69.9
?.20
8.40
6.0
12.0
18. 1
24.1
JO. I
j6.i
42.1
43.1
54.2
60.2 66.2
72.2
}.io
8. JO
6.2
12.4
18.6
24.8
JI.O
J7-2
45-4
49.6
55.8
62.0 68.2
74-4
J. 40
8.20
6.4
12.7
19. 1
25-5
JI.8
J8.2
44.6
50.9
57-3
63.7
70.0
76.4
i.50
8.10
6.5
IJ.O
19.6
26.1
J2.6
J9-I
4;-7
52.2
S8.7
65.2
71.7
78.J
4.
8.
6.7
IS-}
20.0
26.7
33-3
40.0
46.7
53.3
60.0
66.7
73-3
80.0
4.20
7.40
6.9
IJ.8
20.8
27.7
J4.6
41-5
48.4
55.4
62. J
69.2
76.1
8J.1
4.40
7.20
7-1
14.J
21.4
28.5
3S.6
42.8
49-9
S7.0
64.2
71.3
78.4
85.6
5.
7.
7-3
14.6
21.9
29.2
36-5
4J-7
51.0
S8.3
65.6
72.9
80.2
87.5
5.20
6,40
7-4
14.8
22.2
29.6
31.0
44.4
51.9
59-3
66.7
74.1
81. 5
88.9
5.40
6.20
7-5
15.0
22.4
29.9
i7-4
44.9
52.3
59-8
67.3
74.8
82.2
89.7
6.
6.
7-5
15.0
22.5
JO.O
37-5
45 -o
52.5
60.0
67.5
75.0
"•'
90.0
306
HINTS TO TRAVELLERS.
Table XXIII. (continued).
T = Approx.
■ Long, in
a = MEAN OP SECOND L>IFFEKENCE8.
■ 1
1
1
Tiine;
^O'oo
20««<=
jbceo
40S?o 50»ec
isec
2"o
3.eo
4»eo '5M0
6"ec
l,.ec
! 8"o
' n'f
H. Mi
H. M.
«
n
li n II
II
// //
It 1 //
t "
• /,
/'
>•
p.
12.
0.0
0.0
0.0 0.0 0.0
0.0
0.0 0.0
0.0 ' 0.0
0.0
0.0
0.0
0.0
O.IO
11.50
O.I
O.I
0.2 O.J O.J
0.0
0.0 0.0
0.0 0.0
0.0
0.0
0.1
O.I
0.20
11.40
O.I
O.J
0.4 0.5 , 0.7
0.0
0.0 i 0.0
0.1 0.1
O.I
O.I
0.1
O.I
O.JO
11.30
0.2
0.4
0.6 0.8 I.O
0.0
0.0 I O.I
0.1 0.1
O.I
O.I
0.2
0.2
0.40
11.20
O.J
0.5
0.8 I.O I.J
0.0 j O.I O.I
0.1 0.1
0.2
0.2
0.2
0.2
0.50
II. 10
O.J
0.6
I.O , I.J 1.6
0.0 O.I 1 O.I
0.1 0.2
0.2
0.2
O.J
O.J
I.
11.
0.4
0.8
I.I 1.5
1.9
0.0 O.I j O.I
0.2 0.2
0.2
O.J
O.J
O.J
1. 10
10.50
0.4
0.9
I.J 1.8
2.2
0.0
O.I i O.I
0.2
0.2
O.J
O.J
0.4
0.4
1.20
10.40
0.5
I.O
1.5 1 2.0
2.5
0.0
O.I i-O.I
0.2
0.2
O.J
O.J
0.4
0.4
. I. JO
10. JO
0.5
I.I
1.6
2.2
2-7
O.I
0,1 0.2
0.2
0.3
O.J
0.4
0.4
O.S
^ 1 ,40
10.20
0.6
1.2
1.8
2.4
3.6
O.I
O.I { 0.2
0.2
O.J
0.4
0.4
O.S
0.5
. 1.50
10.10
0.6
1.3
1.9
2.6
3.2
O.I
O.I \ 0.2
O.J
O.J
0.4
0.5
0.5
0.6
2.
10.
0.7
1.4
2.1
2.8
3.5
O.I
O.I 0.2
O.J
O.J
0.4
0.5
0.6
0.6
2.10
9.50
0.7
1-5
2.2 J.O
3.7
O.I
O.I 1 0.2
O.J
0.4
0.4
0.5
0.6
0.7
2.20
9.40
0.8
1.6
2. J 3.1
3-9
O.I
0.2 1 0.2
O.J
0.4
0.5
O.S
0.6
0.7
2. JO
9. JO
0.8
1.6
2.5 3. J
4-1
O.I
0.2 0.2
O.J
0.4
0.5
0.6
0.7
0.7
2.40
9.20
0.9
1-7
2.6 J. 5
4-3
O.I
0.2 O.J
O.J
0.4
O.S
0.6
0.7
0.8
2.50
9.10
0.9
1.8
2.7 J. 6
4-5
O.I
0.2 O.J
0.4
0.5
0.5
0.6
0.7
0.8
J.
9.
0.9
1.9
2.8 J. 7
4-7
O.I
0.2 O.J
0.4
0.5
0.6
0.7
0.7
0.8
J. 10
8.50
I.O
1.9
2.9 J. 9
4.9
O.I
0.2 O.J
0.4
0.5
0.6
0.7
0.8
0.9
J. 20
8.40
I.O
2.0
J.O 4.0
5.0
O.I
0.2 1 O.J
0.4
0.5
0.6
0.7
0.8
0.9
3.30
8. JO
1.0
2.1
J.I 4.1
5.2
O.I
0.2
O.J
0.4
0.5
0.6
0.7
0.8
0.9
3.40
8.20
I.I
2.1
J. 2 4.2
5-3
O.I
0.2
O.J
0.4
0.5
0.6
0.7
0.8
I.O
3.50
8.10
I.I
2.2
i-i 4-3
5-4
O.I
0.2
O.J
0.4
O.J
0.7
0.8
0.9
I.O
4.
8.
I.I
2.2
i-i 4-4
5.6
O.I
0.2
O.J
0.4
0.6
0.7
0.8
0.9
I.O
4.20
7.40
1.2
2. J
3.5 4-6
5.8
O.I
0.2
O.J
o.S
0.6
0.7
0.8
0.9
I.O
4.40
7.20
1.2
2.4
3.6 4.8
5-9
O.I
0.2
0.4
0.5
0.6
0.7
0-8
I.O
I.I
5-
7. 1.2
2.4
3.6 4-9
6.1
O.I
0.2
0.4
O.S
0.6
0.7
0.9
I.O
I.I
6.
6. 1.2
2.5
3.7 5-0
6.2
O.I
0.2
0.4
0.5
0.6
0.7 0.9 \ I.O
I.I
TABLES.
307
Table XXIV.— Angles subtended by a 10-ft. Eod at Distances feom
50 TO 1500 Feet.
Feet.
Angle.
Feet. '
A
ngU
Feet. 1
Angle.
Feet.
ingl
e.
Feet.
Angle.
/ II
1
//
1 II
/
//
1 n
50
11 27 ij
92
5
54
24
144
58 44
191
2
59
59
276
2 4 33
SI
II 14 4
98
5
50
47
145
57 5
192
2
59
3
278
2 3 39
52
II I 7
99
5
47
15
146
55 28
193
2
58
7
280
2 2 46
53
10 48 38
100
5
43
46
147
53 51
194
2
57
12
282
2 I 54
54
10 j6 34
lOI
5
40
27
148
52 17
195
2
56
i3
284
2 12
55 1
10 25 3
102
5
37
32
149
50 43
196
2
55
23
286
2 12
56 '
10 ij 5i
103
5
a
45
150
49 "
197
2
54
36
288
I 59 22
57
10 3 7
104
5
30
33
151
47 38
198
2
53
37
290
I 58 32
58
9 52 43
105
5
27
24
152
46 10
199
2
52
49
292
I 57 44
59
9 42 40
106
5
24
19
153
44 41
200
2
51
53
294
296
I 56 55
6o
9 n 58
107
5
21
17
154
43 12
202
2
50
IJ
I 56 8
6i
9 23 ^4
108
5
18
17
155
41 47
204
2
48
46
293
I 55 21
62
9 14 28
109
5
15
23
156
40 22
206
2
46
47
300
I 54 35
6j
9 5 42
no
5
12
31
157
38 58
208
2
45
16
302
I 5? 49
64
8 57 9
III
5
9
42
158
37 34
210
2
4J
42
304
I 5! 5
65
8 48 53
112
5
6
56
159
36 12
212
2
42
306
I 52 20
66
8 40 52
113
5
4
13
160
34 51
l\t
2
40
38
308
I 51 36
6-,
8 33 6
114
5
I
33
161
3
a n
2
39
8
310
I 50 53
68
8 25 33
11;
4
58
56
162
3
}2 12
218
2
37
41
312
I 50 II
69
8 18 ij
116
4
56
21
163
30 54
220
2
36
16
316
I 49 29
70
8 II 7
117
4
53
50
164
29 37
222
2
34
51
I 48 47
71
8 4 II
118
4
51
20
165
23 ■ 21
226
2
3i
28
318
I 48 6
1^
7 57 28
119
4
"•l
57
166
27 5
2
32
6
320
I 47 25
73
7 50 56
120
4
46
29
167
25 52
228
2
30
46
322
I 46 45
74
7 44 34
121
4
44
6
168
24 38
230
2
29
28
32^
326
I 46 6
75
7 38 22
122
4
41
47
169
23 25
2J2
2
28
10
I 45 27
76
7 32 20
I2J
4
39
29
170
22 13
234
2
26
55
328
I 44 48
77
7 26 28
124
4
37
14
171
21 2
236
2
25
40
330
I 44 10
78
7 20 44
12?
4
35
I
172
19 52
238
2
24
28
332
I 4J 32
P
7 15 9
126
4
32
51
i"J
18 13
240
2
23
14
336
I 42 56
80
7 9 43
127
4
30
41
174
17 34
242
2
22
3
r 42 19
81
7 4 25
128
4
28
34
'■'I
16 26
11^
2
20
23
338
I 41 42
82
6 59 14
129
4
26
29
176
15 19
2
19
44
340
I 41 6
8}
6 54 II
130
4
24
26
177
14 13
248
2
18
37
342
I 40 31
84
6 49 16
IJI
4
22
25
178
13 8
250
2
'7
30
344
I 39 56
85
6 44 26
132
4
20
26
179
12 3
252
2
16
25
346
I 39 (>
86
6 39 44
13}
4
18
28
180
10 59
254
2
15
20
348
I 38 47
87
6 35 8
134
4
16
33
181
9 56
256
2
14
17
350
I 38 13
88
6 30 39
135
4
14
39
182
8 53
258
2
13
15
352
I 37 39
89
6 26 16
136
4
12
46
183
7 51
260
2
12
13
354
I 37 6
90
6 21 59
137
4
10
5^
184
3
6 50
262
2
II
12
356
I 36 34
91
6 17 46
138
4
9
6
185
5 49
266
2
10
13
358
I 36 I
92
6 13 40
139
4
7
16
186
4 49
2
9
14
360
1 35 29
93
6 9 39
140
4
5
33
187
J
3 50
268
2
8
16
362
I 34 58
94
6 5 43
141
4
3
48
188
3
2 51
270
2
7
19
364
366
I 34 26
95
6 I 52
142
4
2
5
189
I 53
272
2
6
23
I 3J 55
96
5 ;8 6
143
4
24
190
56
274
2
^
28
368
I 33 25
Y 2
308
HINTS TO TRAVELLERS.
Table XXIV. (continued). — Angles subtended by a IO-it. Rod at
Distances prom 50 to 1500 Fei:t.
Feet.
■ Aiiglfi.
Feet.
AngI
Feet.
Angle.
Feet.
Angl
e.
Feet.
Angle.
/
n
/
//
1
»
/
//
/ II
no
I n
54
495
1 9
27
666 '
51
37
941
36
30
1224
28 5
ii^
I J2
24
498
I 9
2
672
51
9
948
36
16
I2JO
27 57
Jib
I n
55
501
I H
37
678
50
42
954
36
2
1236
27 49
I 3t
25
504
I 8
12
684
50
15
960
35
48
1242
27 41
Hi
I 30
56
507
I 7
48
690
49
49
966
35
35
1248 27 }2
j8o
1 }o
28
510
I 7
24
696
49
2}
972
35
22
1254 27 25
J82
I 29
59
513
I 7
I
702
48
56
978
35
9
1260
27 17
J84
I 29
31
516
I 6
37
708
48
33
984
34
56
1266
27 9
386
I 29
?
519
I 6
14
7 '4
48
9
990
34
43
1272
27 I
j88
I 28
i6
522
1 5
51
720
47
44
996
34
31
1278
36 S4
26 46
390
I 28
9
525
I ^
29
726
47
21
1002
34
18
1284
V)2
I 27
41
?28
I 5
6
in
46
57
ioo3
34
6
1290
26 39
J96
I 27
18
531
' 4
45
li«
46
35
1014
33
54
A(,6
26 jl
I 26
48
534
I 4
32
744
46
12
1020
33
42
1302
26 24
J98
I 26
24
5!7
I 4
I
750
45
50
1026
33
30
1308
26 17
400
I 2?
56
540
I !
39
756
45
28
io;2
33
18
1314
26 10
402
I 2;
31
54J
I ?
'9
762
45
7
ioj8
33
7
IJ20
26 2
405
I 24
53
546
1 2
58
7O8
44
46
1044
32
5?
1326
25 55
408
I 24
15
549
I 2
37
774
44
25
1050
32
45
1332
25 48
411
I 2J
38
552
I 2
16
780
44
4
1056
32
33
1338
25 41
414
I 2J
2
555
I I
56
786
43
44
1062
32
22
1344
25 34
417
I 22
26
558
I I
36
792
43
24
1068
32
II
1350
2; 28
420
I 21
51
i6i
I I
17
798
4?
5
1074
n
I
1356
25 21
42i
I 21
16
564
I
57
804
42
45
1080
31
49
I3f>2
25 14
426
I 20
42
567
I
38
810
42
26
1086
31
39
1368
25 7
419
I 20
8
570
I
19
816
42
7
1092
31
29
1374
25 I
4J2
I 19
35
573
I
822
4«
49
1098
31
!9
1380
24 54
4J5
I 19
2
576
59
41
828
41
31
1104
31
8
U86
24 48
4?8
I 18
29
579
59
22
834
41
13
1116
30
48
1398
24 j;
441
I 17
57
582
59
4
840
40
55
1122
30
41
1404
24 28
444
I 17
26
585
58
46
846
40
38
1128
30
28
1410
24 22
447
1 16
54
588
58
37
852
40
21
"34
30
19
1416
24 16
450
I 16
24
591
58
10
858
40
4
1140
30
9
1422
24 10
45J
I 15
53
594
57
52
864
39
47
1146
30
1428
24 4
456
I 15
2 J
597
57
55
870
39
31
1152
29
5'
M?4
2J 58
459
1 14
54
600
57
17
876
°
39
•4
1158
29
41
1440
23 52
462
I 14
24
606
56
44
882
38
58
1 164
29
32
1446
23 46
465
1 1}
56
612
56
10
888
38
4?
1170
°
29
33
1452
23 40
468
I IJ
27
618
55
38
894
38
27
1176
29
14
1458
23 35
471
1 12
59
624
55
5
900
38
12
1182
°
29
5
1464
23 28
474
I 12
3:
6jo
° 54
34
906
37
S6
1 188
°
28
56
1470
23 23
477
I ]2
24
636
54
3
912
37
41
1194
28
47
1476
23 17
480
I II
37
642
53
33
918
37
27
1200
28
39
1482
23 12
48J
I II
10
648
53
3
924
37
12
1206
28
31
1488
23 6
486
I 10
44
654
52
34
9?o
36
58
I2I2
28
22
1494
23
4«9
I 10
|8
660
52
5
936
36
45
1218
28
13
1500
22 55
-iV-
> 9
52
TABLES.
309
Table XXV. — Useful Constants.
Ratio of circumference to diameter of a circle
Log
, .. V-
n = 10800' -i-TT
log
. .. log
log
7r2 = 9' 869604401089
Arc of same length as radius = iSo-^.
180° -i- n- = Si"- 2957795 no
io8oo'-J-7r = J4J7'-7467707849 ..
648000" -7- TT = 2o6264"-8o62470964
Tropical year= j65d. 5h. 48m. 47s. '588 = i65d. '242217456
Sidereal year = j65d. 6h. 9m. los. -742 = }65d.-256i74!}2 .. .. log
24h. sol. t. = 24h. jm. 56s. •555J35 sid. t. = 24b. X I '0027^791 .. log 1002
24h. sid. t. = 24h. — (jm. 55s.-90944) sol. t. = i^h X 0-9972696 log 0-997
British Imperial gallon = 277-274 cubic inches log
10 lbs. of distilled water at 62° F. =: i gallon.
Length of sec. pend. in inches, at London, 39- 13929; Paris, J9M2S5; New York,
French metre = j -2808992 English feet = 39-3707904 inches.
I cubic inch of watir (bar. 30 inches. Kahr. therm. 62°) = 252-458 Troy grains.
=: 3-i4i592''5i59P-
= 0-497149872694
= 1-772453850906
= 648000" -j- Tf.
= 1-758122632409.
= 3-536273882793.
= 5*ii4425iJJi7'J
= 2-5625810.
= 2-5625978.
= 0-0011874.
= 9-9988126.
= 2-4429091.
39-1285,
310
HINTS TO TRAVELLERS.
Table XXVI.
-Approximate Time occupied in Course of Post from
London to certain Places Adroad.
Name 'of
^ 2
& g
Name of
Name of g>
g Name of
5- o
Place.
o a
Place.
C W
Place. O
a Place.
e K
Accra .. ..
28 ..
Cape Palmes
20 ..
Manila . . ! 32
.. St. Vincent
Adelaide . .
34 ! ..
Cape Town
19 ..
Marseilles. . i
2 (Cape de
Aden . . . .
11 i ..
Garthagena
21 ..
Mauritius . . 22
Verd) . .
10
^ ,
Alexandria..
5
11
Chicago . .
12
Melbourne sfi
.. St. Vincent
Algiers . . j
2
18
Colombo . .
17 ..
;\Iexico . . 14
.. (We.-it Indies)
12 20
Atnbriz
47
Colon
19 1
.Mumbasa , .
22
Salonica . .
4 ..
Antigua
14
17
Congo
2G ..
.Monrovia . .
20
Samoa
47 ..
Arica —
Constanti-
Monte Video
23
San Francisco
12 ..
(vid Panama)
( ,, Magellan) !
35
nople
4
Montreal . .
9
Santanda . .
2
12
48
Coquimbo . .
42
Montserrat . .
14
7 Santos
23
Ascension . . [
28
Cyprus
11
Moscow . .
3
16 Savanilla . .
22 M
Athens
5
6
Deiagoa Bay
26
Mozambique
49
. . Seychelles. .
17 ..
Auckland(ui«
Denierara . .
13
20
Muscat
24
Shanghai— j
S. Francisco) ;
33
Dominica . .
13
16
>JapIes
2
3 (rid Van- 1
Baden-Baden
22
Falkland Is-
Natal.. ..
25
couver) . . j
36 . .
Baghdad ..
2t
lands
29
Newfound-
(vu'i Suez) )
Baiiamas . .
14
Fiji .. ..
41 .. 1
land
•9
Sierra Leone
14 ..'
Bahia . . . . ^
17
Genoa.. ..
1
7
New York
8
12 Singapore . .
26 ..
Balearic Is-
Gibraltar ..
4
6
Nova Scotia
Smyrna . .
6 ...
lands
3
Gothenburg
1
22
(Halifax) 9
Suez . . . .
7
Bavbadof s . .
11
23
Grand Bassa
19
Odessa ... 3
12 Sydney . .
38
Barceliina . .
1 ' IG
Grenada ..
13
8
Old Calabar
^5
Syracuse . .
3
7
Batavia
27 : . .
Grey Town
21
8
Oporto
.•J
2 Tamatave..
27
Bathurst
12 1 . .
Guadeloupe
13
23
Ottawa . .
9
6 Telieran . .
22 ..
Beirut . . . .
8 j ..
Guayaquil. .
26
Palermo . .
2
22 Teneriffe . .
7 ..
Belgrade . .
2 i 9
Havana . .
- 12
Panama . .
19
8 Tiflis . . . .
10 ..
Belize . . . .
17 8
Hobart
37
Payta
26
Tobago
14 17
Benin . . . .
24 ..
Hong Kong —
Penang
24
Transvaal
Bergen.. ..
4 ! 12
via Brindisi
33
Pornambuco
15
(iiVJ Cape)
23 ..
Bermuda . .
15
..Vancouver
40
Perth . . . .
34
. . Trieste
2 13
Bombay
18
12
Honolulu . .
20
Port-au-
Trinidad . .
13 21
Boston,
Iceland
10
Prince . . 15
Turin
1 3
U.S.A. ..
9
12
Jamaica . .
15
21
Port Said .. 6
Valparaiso —
Brindisi
2
12
King George's
Quebec
9
. . (ri('i Panama)
41 ..
Brisbane
39
Sound . .
31
Rangoon . .
24
.. (,, Magellan)
39
Buda-Pesth..
2
'.'.
Karachi . .
20
Reggio
3
Vancouver
15
Buenos Ayi-es
24
Lagos . . . .
29
Rio de Janeiro
19
Venice
2
Cadiz . . . .
3
12
Lainu
20
St. Helena
18
. . Vichy . .
■il
Cairo . . . .
6
Lima .. . .
31
St. Kitts . .
15
10 Vigo .. ..
3
Calcutta
19
12
Limon
24
St. Louis,
Washington
9
Callao—
Lindi . . . .
29
U.S.A. ..
9
Wellington
36
(vi(i Panama)
31
Lisbon
2
22
St. Lucia
Winnipeg. .
13
C „ Magellan)
45
Madeira . .
4
(West Indies)
12
21 Yokohama—
Cameroons . .
30
Madras
18
12
St.Petersburg
2
22 (fiii Van-
Cape Coast
Malta.. ..
4
St. Paul de
couver) . .
32
Castle . .
26
Mandalay . .
28
Loanda . .
St. Thomas
45
16
(via Suez)
3 Zanzibar . .
43
21
TABLES.
311
Table XXVII, — Approximate Time occupied in the Transmission of Parcels
FROM London to certain Places Abroad.
Accra
Adelaide
Aden
Alexandria, via Gibraltar . .
„ via Brindisi . .
Algiers
Ajaccio
Antigua
Ascension
Baghdad
Barbadoes
Barranquilla
Batavia
Bathurst
Beirut
Belize
Bombay
Brindisi
Buda-Pesth, via Cologne . .
,, via Hamburg . .
Cairo, via Gibraltar
„ ma Brindisi
Calcutta
Cape Coast Castle .. ..
Cape Town
Cayenne
Colombo
Constantinople, via Gibraltar
„ via Marseilles
Cyprus
Delhi
Uemerara
Dominica
Drontheim
Genoa
Gibraltar
Gothenburg
Grenada
Guadeloupe
Halifax (Nova Scotia) . . ' . .
Hong Kong . .
Jamaica
Kiniberley , .
King George's Soiind . . . .
K!arachi
Days. Hours.
Days. Hours.
4
4
15
24
45
12
26
44
14
21
36
27
5
6
6
11
13
32
24
20
23
23
18
9
24
32
14
14
5
2
7
2
14
15
10
43
17
22
40
36
Lagos
Lahore
Lisbon, by direct steamer . .
Madras
Malta, via Gibraltar . .
Mandalay
Marseilles
Martinique
Melbourne
Messina
Muscat
Naples
Natal
Newfoundland
Ottawa
Palermo
Penang
Perth (Western Australia) . .
Port Klizabeth
Port Said, via Gibraltar
„ "wia Brindisi. . ..
Quebec . .
tiangoon
' 29
I ^^ I
1 4 to 8
Reunion 23or33
5
16
45
4
5
27
9
12
5
15
34
45
22
6
16
9
11
37
St. Helena
St. Kitts
St. Lucia (West Indies)
St. Thomas
5t. Vincent (West Indies) . .
Senegal
Shanghai
Sierra Leone . . .. ~.".~.
Singapore .. ... j.. , ..
Smyrna, via Gibraltar . . ..
,, ma Marseilles
Sydney
Tobago
Trieste, via Cologne
,, via Hamburg . . . .
Trinidad
Venice
Victoria (Vancouver Island)
Winnipeg ..
Zanzibar . .
Zurich
N.B. — The times given above do not include the interval between the arrival of a Parcel at its
place of destination and its delivery to the Addressee. Moreover, owing to Customs examination in
the country of destination, a parcel not unfrequently occupies in transmission a longer time than is
stated in the foregoing Table.
812 HINTS TO TRAVELLERS.
Tables* for the Determination of Heights. By Francis
G ALTON, F.R.S.
By the Temperature of Boiling Water.
Enter Table I., \). 313, Avitlithe boiling-point at each of the two stations,
and extract the numbers that stand opposite to them in the column headed
" Altitude, &c." The difference between these numbers gives the dif-
ference of height between the two stations, supj^osing the mean tempera-
ture of the intermediate air to be 32° Fahr. The correction for the
temperature of the air, when it differs from this value, is given in
Table II. We take the meanf of the thermometers (exposed in shade) at
the ujjper and lower stations, and we enter Table II. with that mean
value, and the number that stands opposite to it, in the colimm headed
" Multiplier," must be multiplied with the results obtained from Table I,
Thus :—
At station A the boiling-point — - i95°"i, tabular number = 9040
„ B „ = 2io°-3, „ = 887
Approximate difference of height = 8153 feet.
* These extended Tables will give much facility to the traveller both in
calculating altitudes, and in checking tlie index error of the aneroid, by mt ans
of the boiling-point thermometer. I have computed Table I. from Tables XXVI.
and II., in the liypsometric series in Gnyot's collection. It did not seem worth
while to correct the figures thence obtained for the slight excess of temperature,
viz.: o°*oi5 Fahr. of the French boiling-point over that of the English. It is
too small to be sensible in ordinary instruments, and it becomes totally un-
important in determining differences of level, or changes in the index error of an
aneroid. — F. Galton.
t This represents more nearly the average temperature of the intervening
column of air than any other v.ilue tliat can easily be specified. But it is only
an approximation of the truth.
TABLES.
313
To correct for temperature of intermediate air : —
At station A, temp, of air = 65° Fahr.
„ B, „ =73° „
2) 138
69 = mean temperature of intermediate air.
In Table II. the multijjlier corresponding to 69° is i"o82, and i'o82 x
8153 = 8821 (neglecting decimal fractions).
In those rare cases where greater altitudes are dealt with than are
included within the limits of the table, the traveller should allow 570 feet
for the difference between' 18 5° and 184°; 572 feet for that between 184°
and 183'^; 574 feet for the next interval, and so on.
Table I.
Altitude
Altitude
Altitude
above level
Approxi-
mate cor-
responding
height of
aneroid or
barometer.
above level
aliove level
Boiling
point
Falir.
at wliicb
water boils
at 212°
(temp, of in-
termediate
air being
Boiling
point
Fahr.
at which
water boils
at 212°
(temp, of in-
termediate
air being
Approxi-
mate cor-
responding
height of
aneroid or
barometer.
Boiling
point
Fahr.
at which
water boils
at 212°
(temp, of in-
termediate
air being
Approxi-
mate cor-
responding
height of
aneroid or
barometer.
32° F.).
52° F.).
n° F.).
185-0
14698
17-048
186-7
U7JJ
17-690
188-4
12772
18-35}
•I
14641
17-085
-8
13676
17-729
•5
12716
I8-39J
•2
14584
17-122
-9
13620
17-767
•6
12660
18-432
•i
I4?28
17-160
187-0
1J56J
17-806
•7
12603
18-472
•4
14471
IT 197
-1
H50&
17-844
•8
12547
18-512
•5
14414
i7"23=:
-2
13450
17-88;
-9
12490
18-552
•6
I4J57
17-272
•i
IJJ94
17-922
189-0
'24J4
18-592
•7
14J00
17-Jio
--I
iiJJ7
17-961
-1
12377
18-632
•8
14244
1-7-348
-;
1J281
18-000
•2
12321
18-672
•9
14187
iri^5
■6
13224
I8-OJ9
i
12265
18-712
I86-0
14^0
17-42J
•7
IJ167
18-078
-4
12209
18-753
•I
1407J
17-461
-8
mil
18-117
-5
1215?
18-79}
•2
14017
17-499
-9
13054
18-156
-6
12096
18-83}
•i
U960
I7'5i7
188-0
12998
18-195
-7
12040
18-874
•4
ligoj
17-575
-1
12942
18-235
-8
11984
18-914
•5
ii8S7
17-614
-2
12885
18-274
•9
1 1928
18-955
•6
IJ790
17-652
•i
12829
18-314
190-0
H872
18-996
314
HINTS TO TRAVELLERS.
Table L — continued.
Altitude
j above level |
at which
Boiling water boils
point
Fahr.
igo"!
at 21
(temp, of in-
termediate
air being
n° F.).
Approxi-
mate cor-
responding
height of
aneroid or
barometer.
Altitude
above level
at which
Boiling water boils
point at 212°
Fahr. (temp, of in-
termediate
air being
J2° F.).
Approxi-
mate cor-
responding
height of
aneroid or
barometer.
igi-o
•4
•5
•6
■1
•8
■9
•i
■4
•5
■6
■1
•8
•9
I9J-0
•J
•4
•5
•6
•7
•8
•9
194 -o
1I8I6
i9-o;6
194-5
9J7I
1 1 760
19-077
-6
9^5
1 1 704
19-118
-7
9260
11648
19-159
•8
9205
11592
19-200
-9
9150
II5J6
19-241
195-0
9095
11480
19-28J
-I
9040
II424
19-524
•2
8985
Iij68
19-365
•J
89 ?o
11J12
19-407
•4
8875
TI257
19-448
•5
8820
1 1 201
19-490
-6
876;
1 1 146
i9'5.'2
-7
8710
1 1090
I9"57!
■8
865;
IIOJ4
19-615
•9
8600
10978
19-657
196-0
8545
10922
19-699
- 1
8490
10867
19-741
■2
8455
io3ii
19-78}
-J
8j8l
io"55
19-825
•4
8526
10699
19-868
8271
10644
19-910
-6
8216
10588
19-952
•7
8161
105} J
19-995
-8
8107
10477
20-0J7
-9
8052
10422
20 -080
197-0
7997
ioj66
20-I2J
-1
7942
lOJIO
2o-i66
•2
7888
10255
20-208
•J
78?}
10199
20-251
•4
7779
10144
20-294
•5
-724
I0038
20-338
-6
7669
100; J
20- j8l
•7
7615
9978
20-424
-8
7560
992 J
20-467
•9
7506
9867
20-511
198-0
7451
9812
20-554
•I
7J97
9757
20-598
•2
7J4J
9701
20-641
•J
7289
9646
20-685
-4
72J4
9591
20-729
•5
7180
9556
20-77J
-6
7125
9481
20-817
•7
7071
9426
20-861
-8
7016
20-905
20-949
20-99J
21-038
21-082
21-126
21-171
21-216
21-260
21- J05
21-350
21-395
21-440
21-485
21-550
21-576
21-621
21-666
21-712
21-751
21-805
21-849
21-895
Altitude
above level
at which
Boiling water boils
r"^ , «'^'^° height of
tahr. (temp, of m- ^^.^oid or
ternifdiate
air being
32° F.).
Approxi-
mate cor-
responding
barometer.
198-9
199-0
■4
-5
-6
•7
-8
-9
200-0
21-941
-2
21-987
• 5
22-033
■4
22-079
■5
22-125
-6
22-172
•T
22-218
-8
22-264
-9
22-311
202-0
22-358
•I
22-404
-2
22-451
•i
22-498
•4
22-545
•5
22-592
•6
22-639
•7
22-686
-8
22-734
•9
22-781
203-0
22-829
•I
22-876
•2
6962
69-38
6854
6800
6745
6691
6657
6533
6529
6474
6420
6566
6512
6258
6203
6149
6095
604 1
5987
595J
5879
5825
5771
5717
5f.63
5609
5556
5502
5443
5594
5340
5286
52J2
5 '78
5124
5070
5017
4964
491°
4856
4802
4749
469s
4641
22-924
22-971
23-019
23-067
25115
23-16;
23-211
23-259
23-308
23-356
25-405
23-45}
25-502
25-550
2} -599
23-648
25-697
23-746
2!-795
23-845
25-894
23-9t3
25-995
24-042
24-092
24-142
24-191
24-241
24-291
24-Ml
24-391
24-442
24-492
24-542
24-593
24-644
24-694
24-745
24-796
24-847
24-898
24-949
25-000
25-051
TABLES.
315
Table I. — continued.
Altitude
Altitude
Altitude
above level
at which
Approxi-
1
above level
at whicli
Approxi-
above level
at which
Approxi-
Boiling
point
Fahr.
water boils
at 212°
temp, of in-
termediate j
air being |
mate cor-
responding
height of
aneroid or
barometer.
iJoilmg water boils
point at 212°
Fahr. (temp, of in-
termediate
air being
mate cor-
responding
height of
aneroid or
barometer.
Boiling
point
Fahr.
!
water boils
at 212°
temp, of in-
termediate ,
air being '
mate cor-
responding
height of
aneroid or
barometer.
32° F.).
32" F.).
i
32° F.).
469
2C3-i
4588 75-IOJ
207-2 2516
27-179
211 -I
29-390
•4
4535 25-154
•3 ; 2464
27-231
•2
4n
29-449
•5
4482 1 25-206
-4 • 2411
27-286
-3
365
29-508
•6
4428 25-257
•5 ; 2358
27-341
■4
Jn
29-566
•1
4J75 1 25-3°9
-6 2305
27-397
■5
261
29-625
•8
4?22 1 25-J61
•7
2252
27-452
-6
208
29-684
•9
4268 25 -41 J
-8
2199
27-507
-7
156
29-744
204-0
4215 25-465
•9
2146
27-563
•8
104
29-803
•I
4161 25-517
208-0
2094
27-618
-9
52 .
29-862
•2
4107 , 25-569
•I
2041
27-674
2I2-0
29-922
•i
4053 ! 25-621
•2
1989
27-750
•I
- 52
29-981
•4
4000 25-674
•3
1956
27-786
•2
— 104
30-041
•5
3947 : 25-726
■4
1884
27-842
-3
- 155
30-101
•6
38-M 25-779
•5
1831
27-898
•4
— 207
30-161
•7
3841
25-8;i
-6
1778
27-954
-5
- 259
30-221
•8
3788
25-884
•7
1726
28-011
•6
- 3"
30-281
•9
3735
25-9J7
-8
1673
28-067
-7
- 363
30-341
205-0
3682
25-990
•9
1621
28-125
-8
- 414
30-401
-I
3625
26-045
2C9-0
1568
28-180
•9
- 466
30-461
•2
3574
26-096
-1
1516
28-237
2I3-0
- 518
30-522
•i
3521
26-149
•2
1463
28-293
-I
- 570
30-583
•4
3468
26-202
-3
1411
28-350
-2
- 621
30-644
•5
3416
26-255
•4
1358
28-407
•3
- 673
30-705
-6
3363
26-309
■5
1306
28-464
■4
- 724
30-766
•1
3310
26-362
-6
1254
28-521
• i
- 776
30-827
-8
3256
26-416
•7
1201
28-579
•6
- 828
30-888
•9
3203
26-470
-8
1149
28-656
•7
- 880
30-949
206 -o
3151
26-523
•9
1096
28-693
-8
- 9J2
31-010
-I
3098
26-577
210-0
1044
28-751
-9
- 983
31-071
•2
3045
26-631
•I
992
28-809
214-0
-1035
31-132
•?
2992
26-685
•2
9'9
28-866
-1
-1086
31-194
•4
2939
26-740
•3
887
28-924
-2
1 -1138
31-256
•5
2886
26-794
•4
83 5
28-982
•3
-1189
31-318
-6
2833
26-848
•5
783
29-040
-4
! -1241
31-380
••]
2780
26-Qoj
-6
730
29-098
-5
! -1293
31-442
•8
2727
26-957
•7
678
29-156
-6
-1J44
-1396
31-504
•9
2674
27-012
-8
626
29-215
-7
31-566
207-0
2622
27-066
•9
57J
29-273
-8
1 -1447
31-628
•I
2569
27-121
211-0
521
29-331
-9
-1549
31-690
316 HINTS TO TRAVELLERS.
Tablk II. — Correction fob Temperature of Intermediate Air.
Mean tempe-
Mean tempe-
Mean tempe-
Mean tempe-
rature of in-
termediate
Multiplier.
rature of in-
termediate
Multiplier.
rature of in-
termediate
Multiplier.
rature of in-
termpdiate
Multiplier,
air. .
air.
air.
air.
o
20
0-97J4
J7
I-OIII
54
1-0433
70
I ■0866
21
0-9756
38
I-0I3i
55
1-0511
71
22
0-9778
J9
1-015;
56
1-05J?
72
1-0883
2J
0-9801
40
1-0177
57
1-0555
1i
1-0911
24
0-982;
41
1-0199
58
1-0577
74
i-c^?J
25
0-9845
42
1-0222
|9
1 -0599
"^f
1-0955
26
27
0-9867
0-9889
4J
44
1-0266
60
61
I -0622
1-0644
76
77
1-0977
1-0999
28
0-9912
45
1-0288
62
1-0666
73
I -1022
29
o-99?4
46
I-OJII
6}
I -0688
79
1-10A4
1-1066
JO
0-9956
47
I-OJJ}
^4
1-0711
80
31
0-9978
48
I-OJ55
65
1-07JJ
81
I - 1088
J2
l-oooo
49
1-OJ77
66
I -0755
82
i-iiii
Ji
I-0022
50
I-OJ99
67
1-0777
8J
i-inj
H
1-004^
1-0066
51
1-0422
68
1-0799
84
1-1156
35
52
I -0444
1-0466
69
1-0822
85
1-1178
J6
I-C088
5i
Wlicu the boiling point at the upper station alone is observed by the
traveller, he sometimes has the opportunity of availing himself of some
established observatory at no great distance, to serve as the lower station.
A memoir by E. Scott, f.r.s., Secretary to the Meteorological Office, pub-
lished with a map in Vol. XI. of the ' Journ. Roy. Meteor. Soc.,' shows the
distribution of stations past and present, over the globe. Bat these are
continually changing, so the intending traveller should seek the latest
information at the Meteorological Office, 63, Victoria Street, S.W.
Usually, however, the traveller has no option but to take the mean
height of the barometer, reduced to the sea-level, in the district in which
he is, and for the same season of the year, and to use this in the place of
observations at a lower station. He will find what he wants in the maps
of mean barometric pressure, reduced to sea-level, that are given in most
of the physical atlases. Berghaus' is the most recent of these; he
gives one chart for summer and one for winter.* The charts published
by the Meteorological Office refer to the ocean only, but they have the
advantage of being quarterly, and are therefore preferable whenever the
traveller's station is near the coast. It seems impossible to compress
the information given by these charts into a form suitable to these pages,
* See Meteorological Maps, p. 356.
TABLES. 317
especially as the meau barometric height sometimes varies greatly in
neighbouring places. The distance from Takutsk in Siberia to the Sea of
Okhotsk is only 500 miles, yet in winter the calculated mean heights of
the barometer at these two places, when reduced to sea-level, differ as
much as o • 8 inch. From the latitude of Valdivia in S. America to Cape
Horn, the distance is 900 miles, and the mean difference of barometric
pressure is 0*5 inch. Vancouver is another district where the mean
barometer differs much at moderate distances.
Whenever the observations at the upper and lower stations are not
strictly simultaneous, or when the mean barometer is taken in place of
the lower station, the correction for diurnal variation must not be
omitted, especially in the troj^ics where, in other respects, the barometer
is very steady. The mean amount of diurnal variation in different parts
of the world is also given in Berghaus' maj^s. An error of one or two
hundred feet might often be caused by the neglect to allow for it.
The traveller cannot be too strongly urged to have his boiling-point
theimometer verified both before starting and after returning. Their
index error is apt to vary, the thermometer reading lower than it should
do after frequent use. This is especially the case for the first few years
after they are made.
By Barometer or Aneroid.
The small but complete Tables (pp. 319, 320) will be especially useful to
those who carry a mountain barometer and are anxious to make accurate
determinations, but are not furnished with larger tables. These are
calculated by Loomis, and are extracted from Guyot's collection.
Part I. gives the altitude, subject to correction, for the temperature of
the air, and for the other iniluences which are the subjects of Parts II.,
ni., IV., and V.
Method of Computation. — (i) Take from Part I. the two numbers cor-
responding to the two barometric heights; (2) from their difference sub-
tract the correction found in Part II., with the difference between the
thermometers that are attaclied to the barometers {Mem. : this correction
is not wanted for aneroids, for their works are mechanically compensated
for temperature); (3) for the temperature of the intermediate air between
the two stations, multijily the nine-hundredth part of the value already
obtained by the difference between the sum of the temperatures at the
two stations and 64°. This correction is additive when the sum of the
temperatures exceeds 64°, otherwise it is subtractive; or, what comes
*
318 HINTS TO TKAVELLERS.
to the same thing, use the multiplier already given in Table II., p. 316.
(4) For further precision take corrections from Parts III. and IV., also
from Part V., when the lower station is so high as to bring the case
within the range of that table : —
TT„„», c».ti».. Lower Station
^Example i.) ^PP«^ ^Ution. ^^ ^^
o o
Thennometer in open air 70-5 .. 77-5
Thermometer in barometer -Jo'^ .. 77*5
Inches. Inches.
Barometer 23-66 .. 30-046
Latitude 21°.
Parti, gives (^°''^°'?i^.''^?«« ^"^IfT
^ I for 2j -66 inches 2i4o6'9
Difference 6242-8
Part II. gives for 77°-5 — 7o°-3 (= 7°-2) —16-9
Approximate altitude 6:25-9
6225 -9 X (17'^-'; -f 7o°-;-64°)=6-9i8X8r8 = +579--*
900
Nearly correct altitude .. .. .. 6805-6
Part III. gives for above altitude and latitude 21° -HJ'J
Part IV. gives for above altitude . . . . . . . . . . . . . . 4- 19- }
Part V. is not used in this case .. .. .. .. o-o
Correct height above sea 6838-2 feet.
(^Example 2.)
The Lower Station is in Lat. 30°, 4890 ft. above sea-level.
Upper Station. Ixiwer Station,
o o
Thermometer in open air 32 .. 89
Thennometer in barometer. . .. ,, .. .. 35 .. 89
Inches. Inches.
Barometer 15 '76 .. 25-07
Part L gives ff°'^ ^5 ■°2?"'=^^^ "9i9-J
° lfori5-76mches 10791-3
Difference 12128
Part II. gives for 89° - 35° - 126
Approximate altitude . , . , . . 1 2001
12001^6 X (89° 4- 32° -64°) =13-3x57 = +758
900
Nearly correct altitude 12"; 59
Height of Lower Station . . . . . . 4890
17649
From Part III. 22
From Part IV 56
From Part V. 7
Altitude above the sea-level 177J4
For high elevations it is needless to pay attention to decimals.
• If Table II., p. 320, had been used, we should have written —
7T!-1+J?°^ = 74° nearly.
2
The corresponding multiplier is I "093 3
I 0933 X 6225-9 = 6806-8,
TABLES.
319
PART I.
Argument, the observed Height of the Barometer at either Statics'.
Hches. Feet. Diff. Inches. Feet Diff. Inches.' Feet. | Diff. Inches. i Feet,
1396-9
16; J -^
1867-6
2099-9
2JJ0-I
2553-J
2784-5
3008-7
32JI-I
M5I-6
3670-2
3887-0
4102-0
4,-26-9
4756-7
4944 '9
5151-4
5J56-4
5559-7
5761-4
5961-6
6160- (
6J57-5
6555-2
6747-5
6940-3
7131-7
7J2I-7
7510-3 :
7697-6
7883-6
8068-2
8251-5
8433-6
8614-4
8794-0
8972- J
9149-5
9325-5
9500-5
9673-8
9846 - 2
10017-5
10187-7
10356-8
10524-8
10691-8
10857-7
.1022-5
11I86-?
236-4
234-i
232-3
230-2
228-2
226-2
224-2
222-4
220-5
218-6
2i6-8
215-0
213-3
211-6
209-8
208-2
206-5
205-0
203 -i
201-7
200-2
198-7
197-2
195-7
194-3
192-8
191-4
190-0
188-6
187-3
186-0
184-6
183-3
182-1
180-8
179-6
178-}
177-2
176-0
174-8
173-5
172-4
171-i
170-2
168-0
167-0
165-9
164-8
163-8
5-0
6-1
6-2
6-3
6-4
6-5
6-6
6-7
6-8
6-9
7-0
7-1
8-9
9-0
9-1
9-2
n
9-4
9-5
9-6
9-7
9-8
9-9
20-0
20-1
20-2
20-3
20-4
20-5
20-6
20-7
20-8
20-9
21-0
11186-3
11349-1
II5IO-9
11671-7
11831-5
11990-3
12148-2
12305-1
12461-0
12616-1
12770-2
12923-5
13075-8
15227-3
13377-9
I J527-6
13676-5
13824-5
15971-7
14118-0
14263-6
14408-3
14552-3
14695-4
14837-8
14979-4
15120-3
15260-3
15399-7
15538-3
15676-2
15813-3
15949-3
16085-5
16220-5
16354-8
1^88-5
16621-4
16753-7
16885-3
17016-3
17146-6
17276-3
17405-3
17533-7
17661-4
17788-6
17915-1
18041-0
18166-3
I829I-O
162-8
i6i-8
160-8
159-8
158-3
157-9
156-9
155-9
155-1
154-1
153-5
152-3
151-5
150-6
149-7
148-9
148-0
147-2
146-3
145-6
144-7
144-0
145-1
142-4
141-6
140-9
140-0
159-4
138-6
137-9
157-1
156-5
135-7
155-0
154-5
135-7
132-9
152-3
151-6
151-0
150-5
129-7
129-0
128-4
127-7
127-2
126-5
125-9
125-5
124-7
21-0
21-1
21-2
21-3
21-4
21-5
21-6
21-7
21-8
21-9
22-0
22-1
22-2
22-3
22-4
22-5
22-6
22-7
22-8
22-9
23-0
23-1
23-2
23-3
23-4
25-5
23-6
23-7
23-8
23-9
24-0
24-1
24-2
24-5
24-4
24-5
24-6
24-7
24-8
24-9
25-0
25-1
25-2
25-3
25-4
25-5
25-6
25-7
25-8
25-9
26-0
18291-0
18415-1
18558-7
18661-6
18784-0
18905-8
19027-0
19147-7
19267-8
19387-4
19506-4
19624-9
19742-9
I 19860-3
19977-2
20093-6
I 20209-4
20324-8
20439-6
20554-0
20667-8
20781-1
20894-0
21006-4
21118-3
212i9-7
21340-6
21451 -I
21501-1
21670-6
21779-7
21888-4
21996-6
22104-3
22211-6
22318-4
22424-8
22530-8
22636-4
22741-5
22846-5
22950-6
23054-4
25157-9
25261-0
23363-6
23465-9
25567-7
23669-2
25770-3
23871-0
124-1
123-6
122-9
122-4
121-8
121-2
120-7
120-1
119-6
119-0
118-5
118-0
1.7-4
116-9
116-4
115-8
115-4
114-8
114-4
115-8
115-5
112-9
112-4
111-9
111-4
110-9
II0-5
110-0
109-5
109-1
108-7
io8-2
107-7
107-5
106-8
106-4
106-0
105-6
105 -I
104-8
104-5
103-8
103-5
103 -I
102-6
102-5
101-8
101-5
101 -I
100-7
26-0
26-1
26-2
26-3
26-4
26-5
26-6
26-7
26-8
26-9
27-0
27-1
27-3
27-5
27-4
27-5
27-6
27-7
27-8
27-9
28-0
28-1
23-2
28-3
28-4
28-5
28-6
23-7
28-8
28-9
29-0
29-1
29-2
29-3
29-4
29-5
29-6
29-7
29-8
29-9
30-0
30-1
50-2
30-3
30-4
50-5
50-6
30-7
30-8
30-9
31-0
i 23871-0
25971-3
24071-2
. 24170-7
24269-8
24368-6
24467-0
24565-1
24662 • 7
24760-0
24857-0
24953-6
25049-3
25145-7
25241-2
25336-4
25431-2
25,-25-7
25619-9
25715-7
25307-1
25900-3
25993-1
26085-6
26177-7
26269-6
26361-1
26452-3
26543-2
26633-7
26724-0
26813-9
26903 - 5
26992-8
27081-9
27170-6
27259-0
27347-1
27434-9
27522-5
27609-7
27696-6
27785-3
27869-7
27955-7
28041-5 ;
28127-1
28212-3
28297-3
28382-0
28466-4
ico-j
99-9
99-5
99-1
98-8
98-4
98-1
97-6
97-5
97-0
96-6
96*2
95-9
95-5
95-2
94-8
94-5
94-2
93-8
93-4
95-2
92-8
92-5
92-1
91-9
91-5
91-2
90-9
90-5
90-3
89-9
89-6
89-5
89-1
88-7
88-4
87-6
87-2
86-9
86-7
86-4
86-0
84-7
84-4
320
HINTS TO TEAVELLERS.
PART II.
COKnECTION DUB TO T — ^T', OR THR DiFrRRRVOE OP THE TbMPKRATDURS OF THK RaROWETF.RS THRM8ELVE8
(not Fore THAT OF TIIK INTICItMRDIATK AIll) AT THK TWO STATIONS.
This Correction is
Negative when the Temperature at the upper station is
lowest, and vice versa.
T— T'.
Correction.
T— T'.
Correction.
T— T'.
Correction.
T— T'.
Correction.
T— T'.
Correction.
T— T'
Correction.
Falir.
Feet.
Fahr.
Feet.
Fahr.
Feet.
Fahr.
Feet.
Fahr.
Feet.
Fahr.
Feet.
^
I
2-i
14
J2-8
27
bi-2
40
9?-6
5J
12A-I
126-4
66
154-5
156-8
2
4-7
IS
i5i
28
65-5
41
96*0
54
67
J
7-0
i6
37-5
29
67-9
42
98-i
55
128-7
68
159-2
4
9"4
17
^9-8
}o
70-2
4J
loo'7
5<>
iji-i
69
161-5
5
II-7
i8
42-1
ii
72-6
44
loj-o
57
ijr4
70
i6}-9
6
i^-o
i6*4
19
44-5
46-8
it
74-9
45
105 -J
58
ij;-3
71
166-2
1
20
a
77-|
40
107-7
59
IJ8-I
72
i63-6
8
18-7
21
49-2
H
79-6
47
IIO'O
60
140-4
7J
170-9
9
21*1
22
51-5
35
81-9
48
II2'4
61
142-8
74
I7J-J
lO
2J-4
2}
5r8
ib
84- }
86-6
49
114-7
62
145-1
75
175-6
II
2;-8
24
56-2
in
50
117-0
6}
147-5
76
177-9
12
28-1
25
58-5
38
89-0
51
119-4
64
149-8
77
i8o-}
IJ
Jo-4
26
60-9
39
91 -J
52
I2I-7
65
152-2
7»
182-6
PART III.
PART
CORHF.CTION
DUE TO THE
Change of
IV.
PART V
GltAVlTV
FllOM
rHE Latitude of
Correc-
45°
OF
TO THE Latitude of the Place
Obsebvation.
tion FOR
I)E-
Cokkection due to the Height of the
Lower Station.
Positive from Lat. 0°
to 45°;
OF
Gkavitt
ON A
Negative J rom
Lat. 45
= to 90°
Always Positive.
Latitude.
Verti-
CAX.
Height of Barometer at Lower Station.
io°
App.
0°
40°
45°
Always
Positive.
App.
16 in.
18 in. j 20 in. 22 in.
24 in.
26 in. 28 in.
Alt.
90°
80°
70°
60°
50°
Alt.
Feet.
Feet.
Feet.
Feet.
Feet.
Feet.
Feet.
Feet.
Feet.
Feet.
Feet. 1 Feet.
Feet.
Feet. Feet.
Feet.
1000
2-6
2-5
2-0
i-J
0-5
2-5
1-6
1-3
i-o 0-8
0-6
0-4 0-2
1000
2000
5-J
5-0
X-\
2-6
0-9
5-2
3-1
2-5
2-0
i-S
i-i
0-7 o-j
2000
3000
7-9
7-5
4-0
1-4
7-9
V3
3-8
3-0
2-i
1-7
i-i 1 0-5
^000
4 DOG
10-6
lo-o
8-1
5-3
1-8
IO-8
5-1
4-0
3-1
2-2
1-4 ; 0-7
4000
5000
U-2
12-4
lo-i
6-6
2-J
U-7
7-8
rt
5-0
3-8
2-8
1-8 0-8
5000
6300
15-9
14-9
12-2
7-9
2-8
i6-7
9-4
6-0
4-6
3-3
2-1 i-o
6000
7000
18-5
17-4
14-2
9-3
i-2
19-9
ii-o
8-9
7-1
5-4
3-9 ' 2-5 ' 1-2
7000
8000
21-2
19-9
16-2
10-6
3-1
23-1 ,
12-5
10-2
8-1 6-2
4-4 2-8 1 !■}
8000
9000
2r8
22-4
i8-i
11-9
4-1
^^'i i
14-1
II-4
9-1 { 6-9
S-O 1 i-2
1-5
9000
lOOOO
26-,-
24-9
20- J
Ii-2
4-6
1 29-8 1
15-7
12-7
lo-i 1 7-7
5-5 1 3-5
1-7
loooo
1 1000
29- 1
27-4
ll-i
14-6
5-1
33-3
17-2
14-0
ll-l 8-5
6-1 j-9
1-8
IIOOO
12000
ji-8
29-9
24-4
15-9
5-5
36-9
18-8
I5-J
I2-I 9-2
6-6
4-2
2-0
12000
IJOOO
M-4
;2-4
26-4
17-2
6-0
40-6
20-4
16-5
ij-l lo-o
7-2
4-6
2-2
liOOO
14000
jyi
M-9
28-4
18-5
6-4
°
44-4
21-9
17-8
14-1 IO-8
7-7
4-9
2-3
14000
IJOOO
39-7
iVi
30-4
19-9
6-9
48-J
2J-5
191
I5-I II-5
8-3
S|
2-5
15000
16000
42-4
?9-8
32-5
21-2
7-4
52-3
25-1
20-J
l6-I 1 I2'i
8-8
5-6 2-7
16:00
17000
45-0
42-J
?6-5
22-5
7-8
56-4
26-6
21-6
I7-I 1 13-1
9-4
6-0 2-8
17000
18000
47-7
44-8
2}-8
8-i
60-5
28-2
22-9
i8-l 1 lj-8
9-9 6-j 1 j-o
18000
19000
50-i
47-3
^8-6
25-2
8-7
64-8
29-8
24-1
19-2 14-6
IO-5 6-7 ; j-2
19000
20000
5?-o
49-8
40-6
26-5
9-2
69-2
31-3
25-4 1 20-2 1 15-4
ii-o 7-0 j-i
20c 00
21000
55-6
52-?
42-6
27-8
9-7
7r6 '
32-9
26-7 j 21-2 1 16-I
II-6 7-4 j-5
21000
22000
58-?
54-8
46-7
29-1
lo-i
78-2
34-5
28-0 , 22-2 : 16-9
12-1 7-7 rn
22000
2JO0O
tl
57-3
io-5
10-6
82-9
j6-o
29-2 2J-2 17-7
12-7 8-1 j-8
2JOOO
24COO
59-8
48-7
jl-8
ii-o
.
87-6
37-6
J0-5 24-2 18-5
ij-2 8-4 4-0
24000
25000
66-2
62-2
50-7
iJ-i
II-5
° 1
92-5
39-1
il-8
25-2
1
19-2
ir8
8-8
4.|
25000
( 321 )
PHOTOGEAPHY.
By W. F. DoNKiN, M.A., F.C.S., A.C., late Lecturer in Chemistry at
/St. Georye's Hospital.
Revised and brought up to date by J. Thomson, Instructor in
Ph fography JR.G. S.
The traveller who wishes to take photographs of the scenery he may-
pass through has first to decide on the size of plate he intends to employ,
for on this will depend the size and weight of all the necessary apparatus.
The smallest size that is worth taking is known as " quarter-jilate,"
measuring 4? x 3i inches; the largest size which admits of the apparatus
being carried by one man is 7^ x 5 inches. Intermediate sizes are 5x4,
and 6i x 4f , or " half-plate."
On high mountain ascents, and in cases where scarcity of porters or
some other reason may compel the traveller to carry his own apparatus,
it may be advisable to have a " quarter-plate " camera, as, although the
pictures obtained are trivial in ajDpearance, excellent enlargements and
lantern slides can be produced from them. In countries where, as in
India, porterage is cheap and easily obtained, large sizes may be adopted,
such as 82 X 6^ or " whole-plate " ; but for general utility and convenience
7^ X 5 is recommended, and in the following remarks it will be assumed
that this is the size adopted.*
The next point to decide is as to the selection of the sensitized medium
for receiving the image— glass plates, celluloid, or other films.
The weight of the entire apparatus necessary for taking twelve pictures,
namely, camera, slides, 12 glass plates, lenses, leather case, and tripod
stand, will be from 20 to 25 lbs. The weight of glass plates 7j x 5 inches
averages 3 lbs. per dozen, and, as the traveller should take with him from
half a gross upwards, it is evident that the chief weight of the necessary
photographic impedimenta is solid glass. This weight may be much
* A " quarter-plate " camera ought to be taken to supplement the work of the
larger instrument, and to be used cither as a hand camera, or on a tripod stand.
322
HINTS TO TRAVELLEKS.
diminished by using flexible celluloid films as the base for the
sensitive gelatine film. Without dou1)t, glass plates yield the best
results ; but celluloid films in the smaller sizes, up to 7^ x 5, approach very
nearly to glass in many respects, and have the advantage of being one-
twelfth the -weight and not liable to breakage. They are exposed in the
same slides, and require the same treatment as glass plates.
As, however, the production of good film negatives requires consider-
able skill and nicety of manii^ulation, it will be well for the traveller who
has not been able to attain cxpertness therein, to provide himself with
glass plates and flat celluloid films. The following list comprises all the
apparatus necessary for taking photographs ou dry gelatine-coated glass
plates or celluloid films.
IJei.lows CaME1!A.
1. A camera.- — This should be of the bellows-bodied fonn, of best
mahogany, thoroughly well seasoned, and it is very convenient for it to
be fitted with what is known as a reversive back. It should have a
moveable front, capable of shifting both vertically and horizontally; and
a swing back ; that is to say, the frame carrying the focussing glass and
sensitive plates must be capable of turning on a vertical axis through
several degrees in each direction away from the normal. There are now
many good eamei'a-makers in Loudon ; among the best may be named
Mr. Meagher, of 21, Southampton PiOw, Eoss, of Bond Street, and Mr.
Hare, of 26, Calthorjie Street, Gray's Inn Eoad.
The essential points reqiiired in a camera for travelling are lightness
combined with strength, rigidity when extended for use, and absence of
loose parts and screws. When the form of camera allows it, the tripod
head is better dispensed with, and a turn-table let into the base board.
If this be not the case, have all screws in duplicate. A convenient screw
PHOTOGEAPHY. 323
is made for fixing the camera to the stand. The thread of the screw is
turned off close to the shoulder, so that the screw revolves in the aper-
ture in the head of the stand, and need never be withdrawn. A second
focussing screen should also be taken, or some fine emery with which to
grind down a glass plate in case of breakage.
Hand cameras. — It is necessary to supplement the note on hand
cameras, as they are now extensively used, and excellent work done with
them. Hand cameras are designed to carry a dozen or more plates or
films in flat sheets or in spools, so arranged inside the camera as to
bo changed after each exposure by simply turning a milled head, or
moving a lever. The Key camera made by the Platinotype Company is
certainly one of the best; it is fitted with metal dark slides for carrying
plates or films, and is well spoken of by Mr. Conway. It may be had either
to carry plates or flat films. These metal slides are light, not easily
damaged, and offer greater security against damp than an ordinary hand-
camera where slides are not used. Where the film takes the form of a
roll, the Luzo hand-camera is excellent, but rolled films are not recom-
mended for travellers' use in hot and humid climates, for reasons which
I will note later on. Mr. Conway's experience of the Key camera for work
in high mountain ranges proves its capabilities for the general work of
exploration. He says: "A traveller who carries glass plates and flat
films will probably bring home a larger percentage of good negatives from
a long mountain journey than one who relies upon spools of films." There
can be no question about the force and accuracy of this statement. My
own experience goes to prove that a camera arranged for glass plates
and flat films is best. There is a certain facility in using rolled films,
bvit the risk of failure is great. The Key camera should be fitted with
a rising front for taking elevated objects in correct drawing when the
instrument is level. Mr. Conway advises that " the angles of the double
backs of tills camera should be made stronger than they usually are.
The shutter spring should be carefully tested for quality before starting,
and a duplicate spring taken, which the traveller should learn to adjust."
In addition a light tripod stand should be taken for supporting the
camera when longer exposures are required than can be given in the
hand. A very satisfactory compromise has been adopted by Capt. Abney
between using the camera in the hand and on a tripod. He rests the
camera on top of a walking stick when making hand exposures, with the
z 2
324 HlN'l'S TO TRAVELLERS.
result that he overcomes all tremor caused by pulsation, and so secures
2)hotographs full of sharp detail. There are a number of excellent hand-
cameras made, those by Ross, Eouch, and Watson may be mentioned.
2. Glides for holdimj the sensitive plates. — These are frames which slide
into the back of the camera in place of the focussing glass, which is
removed. They each hold two sensitive plates, back to back, with an
opaque partition between them, so that a dozen plates will require six
slides or " double backs."
In order to secure the camera against the admission of light when the
plate is being exposed, cover the camera entirely with the focussing cloth
leaving the lens free, and pull out the shutters of the slides under the cloth.
8. A focussing doth. — This is used for keeping out the light while
focussing, being thrown over the camera and the head of the operator.
It is generally made of black velvet, but waterj^roof sheeting is much
better. It should have rings sewn on to one edge, or some arrangement
by which it may be attached to the camera so as not to be blown away.
4. Camera-stand. — There are many varieties of tripod stands, with legs
either folding or sliding into a small compass. For mountainous country
it is of great advantage to have a stand with sliding legs, as they can be
readily altered in length so as to stand firmly on slopes or rocky ground.
Kenuett's is a good form of sliding stand, and is made in two or three
different sizes. The smallest size, weighing about 3 lbs., and measuring
33 in. long when closed, and standing about 4 ft. 6 in. high, is steady
enough to support a 7^ x 5 camera without perceptible vibration in a
moderate wind. That of Hunter & Sands is another very good pattern.
5. A small circular cup level, let into the wood of the camera, for level-
ling the camera on the tripod.
Lenses. — There are many lenses in the market, and as it is imijossible
to do good W'Ork with an inferior lens, it is necessary to exercise gi-eat
care in selecting this part of a photographic outfit. Lenses known as
rectilinear or symmetrical are the most useful to a scientific explorer, and
are equally well fitted for producing jiictorial effect in his work.
Ordinary portrait lenses are designed specially for rapid work, and this
is attained at the cost of qualities in a lens most iiseful to an explorer.
The so-called portrait combination should therefore be avoided, and there
is all the more reason for this as rapid rectilinear and symmetrical lenses
are well adapted for out-door portraiture.
Eectilinear and symmetrical lenses give true images of objects to be
PHOTOGRAPHY.
325
photographed free from distortion, so that straight lines are reproduced
as straight lines. In this way they are invaluable where accurate measure-
ments have to be taken from photographs produced by them.
Eoss and Dalimeyer's ordinary symmetrical and rectilinear lenses aro
excellent for all sorts of landscape work and for photographing buildings,
exterior and interior. In using a camera 7i in. x 5 in. the following
lenses are recommended : —
a. Eoss's portable symmetrical, 5 in. focus. (This embraces an angle
of about 55'' on the long diameter of the plate, and is useful for confined
situations and iuterior.s, but should seldom be used for an open land-
Ross Rapid Syjimetbical. Zeiss Lexs.
scape.) h. Dalimeyer's single meniscus lens, 7 in. focus. (This includes
an angle of about i5" on the Tl in. plate, and will be found the most
universally useful lens for ordinary landscapes, giving a brilliant image
with great depth of focus.) r. Dalimeyer's rapid rectilinear, of about
II in. focus, including about 37^. d. Zeiss's anastigmat, made by Eoss,
consists of a double front lens and a triple back lens. It is intended for
portraits, groups, copying, and general outdoor work. The combinations
being brought closely together, gives them great illuminating power.
They have an angular aperture of from 858 to 908, and can therefore be
used as wide-angle lenses when desired. In consequence of the peculiar
system of correction for ol)lique pencils adopted in these lenses they
bebave somewhat differently from the usual types with regard to the
mode of compensating the effect of the resulting aberrations between
centre and margin of the field. This is, of course, only possible in tJie
326
HINTS TO TRAVELLERS.
case of i^erfcctly plane objects. In all other cases— landscape, instan-
taneous work, or interiors — the centre should be focussed, and rather for
objects at a distance than for near objects. Considerable economy may
be effected by purchasing lenses second-hand from respectable dealers,
such as Messrs. Watson & Son, 313, High Ilolborn ; Mr. Morley, 70, Upper
Street, Islington, or Messrs. Hunter & Sands, of 20, Cranbourne Street, all
of whom can be recommended with confidence.
Focus.- — In place of giving a strictly scientific definition of the term
focus or "focul length" applied to a lens, it will be sufficient for the scope
of this paper to say that focul length means the distance between the
diaphragm of a rectilinear or symmetrical lens, and the ground-glass
screen of a camera. That is when the image of an object, say one
hundred yards in front of the lens, is seen most distinctly on the focussing
screen of the camera.
Exposure tables. — Exposure tables are based on the focul length of a
lens, in relation to the diameter of the diaphragm of a lens. Thus, if
the focus is eight inches and diameter of diaphragm one inch, the relation-
s-
ship will be expressed by ^ or by the uniform standard number 4, and
so on, as in table.
U i; Nus
4
/
8
8
/
i6
/
i6
n
f
22-6
64
/
32
128
/
45-2
256
/
64
Such tables are useful guides to the relative duration of exposure with
diaphragms of different sizes applied to the same lens. They afford
no clue, however, to time of exposure to be given with any particular
lens or diaphragm. This can be best ascertained by experience, as
duration of exposure of a plate or film in the camera depends on the
■sensitiveness of the plate, the time of day, the sun, the state of the atmos-
phere, the nearness or distance of the object to be photographed, etc.
To take an extreme case of the dift'erence of time required to impress the
plate with the image of an exterior view and that of an interior, a
landscape open and well lighted may be taken in the fraction of a second,
while a dimly-lighted interior with the same lens would require an hour,
both being taken with plates coated with the same emulsion.
PHOTOGRAPHY. o27
Sensitive plates or films. — Gelatine plates are now made commercially
by a large number of firms and of great excellence ; they keep indefinitely
before exposure, and for a long time afterwards and before development,
and under some circumstances (as for instantaneous pictures, portraits,
and dimly-lighted interiors) will give results which could hardly be
obtained at all on collodion. Gelatine plates are made of various degrees
of sensitiveness ; the slowest plates are best for ordinary landscape work.
They are generally su])plied in parcels of a dozen each, packed face to
face with strips of folded paper between opposite edges. The card boxes
in which they are usually joackcd are an insufficient protection against
injury and damp. In all cases it is advisable, and for sea voyages and
damp climates essential, to have each package of a dozen plates soldered
down in a tin case, and afterwards packed in a light wooden box with
tow or cotton wool, and the box screwed (not nailed) down. In packing
them up again after exposure or after development, a good plan (due to
Captain Abney) is to provide oneself with a numljer of cardboard frames
exactly the size of the plates, made of strips of card about I in. wide, one
of which is inserted between every two face to face. The packages thus
made up should be soldered down again, and treated with at least as
much care as the original plates. Should there be no available means
of resoldering the boxes, it will be better to have tin boxes with the lid
turned well down, the joinings to be closed by strong well-gummed paper.
It will also be well to be provided with a supply of waterproof paper, or
cloth, as an additional precaution in packing and in case of emergencies.
Sensitive films in rolls or spools are made by the Eastman and other
companies, and may be used successfully in their proper roll-holders when
they can be kept perfectly dry. Flat films made by Fitch, Edwards and
others have many advantages for travellers. The celluloid of which
they are made is very much lighter than glass, and in exposure and
development may be treated in the same way as a glass plate.* When
plates can be carried, the extra weight is compensated for by greater
certainty of success, and general excellence in the photographs.
How to keep jil (lies and films dry. — When the traveller has a long journey
before him, and the prospect of storing his plates and films for months
* A new film has just been iutroduceil l)y Thomas, (if Pull ]\Iall, ami is sairl
not to jiossess the defects of celluloid.
328 HINTS TO THAVKIJ.EHS.
both before and after exposure, it is of the greatest importance tliat pre-
cautious sliould be taken against tlio iuroads of damp. Tliis applies
with full force when the country to be explored has a hot, humid climate.
Plates and lilms that have absorbed moisture, causing decomposition in the
sensitive gelatine coating, are frequently brought back to this country to
be developed, and are the most fruitful cause of failure. The remedy is
simple, but can only be applied when jDacking and repacking the plates.
Some guarantee should be sought from makers of plates and films that
they are i^acked perfectly dry, and that the i:)acking used is also dry.
Assuming that work has to be done in a damp climate and that the plates
have been ex])osed in the camera and require to be rei:)ackod, they should
be dried in a box containing a small quantity of chloride of calcium. The
box used for drying may be also designed to carry the camera and outfit.
It should have a lid with a rim of rubber padding, so that by putting the
lid on and a weight on it, the box would be fairly air-tight. Stack the
exposed plates, or films, in the bottom of box, so separated as to permit
the passage of air between. Place a cujd or saucer on the bottom of box
containing chloride of calciiim. (The chloride should be first dried
on a piece of iron over a fire.) Put on the lid and allow the plates to
remain for an hour or more. Dry all the packing materials, remove the
plates from the box and repack. The chloride will have absorbed the
moisture in the plates, and rendered them quite dry and safe for preserv-
ing for an indefinite length of time.
Apparatus and chemicals for development. — The development of the
plates or films after exposure in the camera requires practice and experi-
ence in order to secure the best results. Instructions for development
are sent out with all commercial plates or jiapers, but many failures
would certainly result from attempting to work by these without some
preliminary practice at home. As plates, Arc, will keep after exposure
(if well protected from damp) for 18 months, or longer if properly
packed, it is not, of course, necessary to develop them en route,
although if the traveller possess sufficient skill, and if ample water-
supply and other facilities can be secui-ed, it will be advantageous for
many reasons to do so. On a long journey, use of convenient resting-
places may be made to develop from time to time a few plates selected
from the whole, both as tests for exposure and ns ]>roof that all the
apparatus is in order. The following list comprises all that is
PHOTOrJRAPHY. .■)29
cabsohitely required for developing 8 or 10 dozen gelatine plates:--
Three papicr-macho dishes, two S-ounce glass measures, three 6-ounce
bottles, containing strong solutions of i)yrogallic acid, potassium
bromide, and ammonia respectively, 1 lb. hyposulphite of soda, and
i lb. alum, both in crystals, 4 or 5 feet of indiarubber tubing and a spring
clip, to make a syphon for a water-supply from a jug or can, a basin
or tub to serve as a sink, a folding rack for draining the plates.
There is a very convenient new developing agent in the market called
Eikonogen, sold in tubes, and may be used as follows : — Break the tube
over a sheet of paper, empty completely both halves by means of press-
ing the tube between the fingers, withdraw the small joieces of wadding
falling therefrom and put the whole quantity of the powder in a bottle
containing 100 cubic-centimetres (Sg ounces) distilled water. (Eain-water
or soft pump- water may also be used.) After being shaken from 3 to 5
minutes, the powder will dissolve, and the developer is then ready for use.
If the plates are over-exposed, increase the quantity of water from 150 to
200 cubic-centimetres, and, if necessary, add a few drops of a solution of
bromide of potassium (1 : 10). The developer may be used several times.
The traveller is recommended for advanced study of photography, sucli
works as that by Captain Abney or by "W. K. Burton, which may l)e had
from any photographic dealers.
The aim of the traveller-photographer should be the production of good
negatives. It often requires years of study on the part of professional
operators (with advantages impossible to the traveller) before thoroughly
good negatives are habitually jn'oduced ; and it must not be supposed
that a person taking up photography for the first time, in a few hurried
moments before departure on a journey, will attain other than very
unsatisfactory results.
The operations necessary for taking a picture are briefly as follows : —
Having selected the position from which the view is to be taken (for valuable
hints as to the artistic production of pictures see Eobinson's ' Pictorial
Effect in Photography '), the tripod stand is first set up, and the head ap-
proximately levelled by means of the pocket level, altering the position or
length of the legs as may be necessary. The camera is next screwed on
to the stand, and the lens selected which on trial is found to include the
required amount of subject. For groups or portraits a long focus lens
with wide aperture, such as Dallmeyer's " Rapid rectilinear," 11 in. focus,
380 HINTS TO TRA.VELLERS.
sliould be used. The next operation is to focus the pieturo accurately on
the ground-glass screen of tlie camera. The focussing-cloth is thrown
over the head and the camera., so as to exclude the light as much as
possible, and while looking at the inverted image on the ground glass
the milled head of the rack adjustment is turned till the image appears
as sharp as possible. The camera is now turned about on its vertical
axis till it exactly includes the view intended to be taken, and the screw
is tightened. It may be necessary to raise or lower the front of the
camera carrying the lens in order to include olyects at a high or low
elevation ; if the vertical range of this sliding front is insufficient, tlie
camera must be tilted ; but, if this is done, care must be taken to set the
focussing-screen vertical again by means of the swing back, and to re-
adjust the focus. The full aperture of the lens should always be used
for focussing, and if the image is not sharp all over the plate it will be
necessary to insert a diaphragm in the lens, using the largest that will
effect the required object. Having then put the cap on the lens, the
hinged frame carrying the focussing-glass is turned over, and one of the
slides carrying the sensitive plates is inserted in its place. The slides
should be exposed as little as possible to the light, especially avoiding
direct sunlight ; however carefully constructed, it is difficult to make
them absolutely light-tight. The shutter of the slide is then withdrawn,
and the exposu.re made by removing the cap from the lens for the
required time. The time of exposure must be estimated according to
circumstances, and it requires considerable experience to judge of it ac-
curately. A record should be kept in a note-book of every plate exposed,
giving the number, date, time, exposure, subject, &c. If the plates
cannot be developed the same evening, and the slides are wanted for
fresh plates, they must be packed up again, and should be numbered.
This is best done by marking the number on the back with a bit of dry
soap, or on the film with a lead pencil. The image on the plate after
exposure is latent and invisible, and has to be develojied. This is effected
by pouring on the plate, laid in one of the flat dishes, a dilute
solution containing pyrogallic acid, ammonia, and potassium bromide.
The excellence of the result largely depends on the due proportion
between these constituents, and here more exi^erience is perhaps neces-
sary than in any other part of the process. The image having
been fully developed, the plate is well washed, and then immersed in
PHOTOGRAPHY. 331
a solution of alum, which hardens the film. After another thorough
washing it is "fixed" by immersion in a solution of sodium hypo-
sulphite, which dissolves out the unchanged bromide of silver, and
being once more well washed it is finished, and must be set up in the
rack to dry spontaneously. On no account must heat be applied, not
even the warmth of sunlight, or the film will melt. When dry it must
be varnished to protect the film. The printing operations are best deferred
till the return home, as they would involve the carriage of a large
amount of extra apparatus. It is generally best to get the printing done
by a professional printer ; but, if the traveller prefers to print from his own
negatives, he will find full instructions in ' The Art and Practice of
Silver Printing,' by Eobinson and Captain Abney.
As regards the expense of a photographic outfit, such as that described
above, the following may be taken as average prices for the largest size
recommended, namely, for plates Is x 5 inches : —
Camera 4 to 5 guineas.
Double slides, about 1 guinea each.
Lenses, as described above, No. 1, 3/. 10s. ; No. 2, 3/. 15s. ; No. 3, V.
These may generally be obtained second-hand, in good condition, at a
reduction of 25 or 30 per cent, on these prices.
The above may be arranged to pack into a solid leather case, conveniently
in the form of a knapsack, measuring about 16 in. wide, 12 in. high, and
5 in. deep. This can easily be carried on the back of one man, and is of
a more convenient shape than the cases generally sold for the purpose.
Tripod stand, 25s.
Lantern, from 2/. to 10s.
Gelatine plates, about 3s. per dozen.
Apparatus and chemicals for development, about 15s.
Total, exclusive of the plates, about 25?.
The plates and other apparatus, with the exception of the knapsack and
its contents, and the tripod stand, are best packed for travelling in a
strong basket, which is much better than a box, being more elastic and
lighter. It will weigh, when packed with the apparatus and a gross of
71 X 5 plates, about 60 lbs.
Travellers interested in anthropology might read Mr. E. F. ira Thurn's
recent paper on the Anthropological Uses of the Camera, published in
the ' Pro-jeedings of the Anthropological Society.'
( r!82 )
VI.
METEOKOLOGY AND CLIWATE.
Bij H. F. Blanfokd, f.r.s.
Before starting on his journey, the traveller should set before himself
what he contemplates as the precise aim and object of liis meteorological
observations, and arrange his outfit and plan of operations accordingly.
This object may be, either (1) a simple record of the weather, (2) a
knowledge of the local climate, or (3) the prosecution of certain special
meteorological inquiries, for which the places he proposes to visit may
afford peculiar advantages.
Since the climate of a country is the average of all its weather conditions
at each season, the observations which are recpiired for the first object
need only to be made systematically and guarded with certain precautions
in order to furnish a valuable contrilmtion towards the second also; and
it may therefore be assumed that, as a general rule, this too is desired.
To accomplish the third object, some previous scientific knowledge and
practice will generally be necessary, and this will best be gained by a
preliminary training under competent guidance. Some suggestions on
this head will be given in the sequel.
Assuming, then, that a knowledge of the climate is the object immediately
in view, the following particulars will more especially claim the traveller's
attention. 1st, the temperature of the air, including the mean temperature,
its diurnal and annual range, and its variability from day to day. 2nd,
the humidity of the air at different seasons, and its changes ; 3rd, the
rainfall, including under this head snow, hail, dew, and other forms of
precipitation ; 4th, the direction and force of the wind ; 5th, the cloudi-
ness or serenity of the sky, with observations of fog and dust-haze ; 6th,
the frequency of storms. The intensity of the sun's heat and the cooling
of the earth at night are also very important elements of climate, but the
METEOROLOGY AND CLIMATE. 333
instruments for measuring them are fragile, and especially liable to de-
struction. And inasmuch as, in the absence of direct observation, the
sun's intensity and the nocturnal cooling may be, to a certain extent,
inferred from the temperature range and some other of the foregoing
observations, their actual measurement can hardly be recommended
except under special circumstances to be noticed presently. The varia-
tions of the pressure of the atmosphere are of less importance as an
element of climate, but they hold a first place in connection with weather
changes, and with the movements of the atmosphere ; and, inasmuch as
the barometer (or aneroid) atfords the readiest means of determining the
elevation of a i:)lace, it will form j^art of the outfit, of most travellers, and
will be here noticed among tlie more indispensable instruments.
Instruments and outfit.- — For the purposes specified in the foregoing
paragraph, the following insptruments are requisite : —
1 self-registering maximum thermometer.
1 „ „ minimum „
1 dry and wet bulb hygrometer.
2 sling thermometers.
1 thermometer for earth temperatures.
1 rain-gauge.
1 aneroid.
1 pocket compass.
Also a portable stand and screen for the thermometers; half a yard of
thin muslin and a skein or two of lamp wick cotton for renewing the
covering of the wet bulb thermometer, a pocket note-book for noting down
the readings of the instruments and other casual observations, and a
ruled register for posting them as a permanent record.
The instruments above enumerated will suffice for ordinary purposes
if the journey is not likely to be very prolonged, and the means of trans-
port such as will not expose them to great risk. If otherwise, all but the
rain-gauge should be provided in duplicate. An ordinary reading lens, of
about 2 in. diameter and 4-in. focus, is sometimes useful for the accurate
and rapid reading of the thermometers. And if the country is one where
no good mercurial barometer is likely to be met with, and circumstances
admit of one being set up at a fixed station, whicli can bo referred to at
intervals, or even the beginning and end of the journey, for the comparison
334 HINTS TO TRAVELLERS.
of the aneroid, it will be a most useful adjunct; but even the most port-
able forms of the mercurial barometer are so fragile, and their transport
on land journeys is attended with so much risk, that, as a general rule,
they can hardly be recommended for the purposes of travel.
Small self-registering thermometers for travellers are prociirable from
the best London makers, and are as trustworthy as the larger observatory
instruments, while they are more portable. The best form of maximum
thermometer is that which has the tube constricted just above the bulb,
so that the column, in contracting after attaining the maximum tem-
perature, breaks at this point. The more usual pattern (Phillip's) has an
air-bubble about an inch below the top of the column. This is apt to
shift in travelling, and sometimes to escape from the column, and the
instrument then ceases to be self-registering. Six's thermometer, which
combines the maximum and minimum in one bent tube, partly filled with
mercury and partly with spirit, is also liable to be deranged in travelling,
and is not more portable than the separate instruments of small size.
The minimum thermometer should be a spirit thermometer of the form
known as Eutherford's, which has an index of black glass immersed in
the spirit column. This is also very liable to derangement in travelling,
and sometimes even when suspended for observation, owing to the
separation of the column. But it is easily rectified after a little practice ;
and the traveller should learn to do this before starting on his journey.
The thermometer must not be immersed in warm water, or otherwise
heated, any such proceeding being attended with great risk, while it is
rarely effectual. The following method is safe and certain. 1st, If the
column is separated but the index remains in the spirit, grasp the in-
strument firmly by the upper end of the scale, taking care not to press on
the tube ; then, holding it at arm's length above the head, swing it down
with a sudden jerk towards the feet, and repeat this till all the jxarts are
reunited. Then let it stand half an hour, bulb downwards, to allow the
last film of spirit to drain from the tube. 2nd, If the iudex has left the
spirit and become fixed in the upper part of the tube, first grasp the
instrument by the bulb end, and, proceeding as just directed, pass about
half the column to the upper end of the tube. Having thus released and
reimmersed the index, reverse the instrument and pass sj^irit and index
back together. 3rd, If an air bubble has penetrated to the bulb, hold
the instrument upright and strike the bottom of the scale smartly on the
METEOROLOGY AND CLIMATE. 335
palm of the left hand repeatedly, until the whole of the air is driven into
the tube. Then proceed as before for reuniting the column. Sometimes,
when in use, a drop of colourless spirit, separated by evaporation, becomes
lodged at the upper end of the tube, causing the thermometer to give too
low a reading ; and this may escape observation unless carefully looked
for. Before suspending the thermometer, and also before taking a reading,
the tube should always be closely examined to ascertain that the column
is entire. Mercurial thermometers are much less liable to derangement.
The hygrometer should consist of two separate thermometers (not
mounted on the same frame), and they should be suspended not less than
6 inches apart. The wet bulb should be provided with a small bottle
having a narrow neck for the water sujjply (not an open cup). The muslin
and wick should be renewed as often as they become dirty. The dry bulb
serves to show the temi^erature of the air at the time of reading, and the
difference of its reading and that of the wet bulb affords the data for
computing the humidity of the air. The hygrometer can only be used for
camp observations. For observations on the march, one of the sling
thermometers should be fitted with muslin as a wet bulb. These ther-
mometers being without attached scales are very portable. Each should
have its own case, of thin brass tube closed at each end, and india-
rubber lined, with a plug of cotton at top and bottom.
Every thermometer should be furnished with a table of corrections for
all parts of its scale. The verification can be effected at the Kew Obser-
vatory on payment of a small fee. It cannot, however, be assumed that
the corrections thus determined will remain constant, since thermometers
undergo a slow change that may continue for many years. But as this
change affects all parts of the scale equally, when an instrument has once
been verified throughoiit, it is sufficient at any subsequent time to revcrify
its freezing-point, by immersing the bulb and lower part of the scale in
crushed, melting ice. Any change, thus determined in the correction of
the freezing-point, may be applied as a further correction to all parts of
the scale.
Travellers in Arctic and Antarctic regions, in Siberia and Canada, in
the winter, in any country indeed in which the temperature often falls
below 0° Fahr., should employ spirit thermometers only, and these should
be verified down to the freezing-point of mercury ( — 37"9°). This too
may be effected at Kew.
336
HINTS TO TRAVELLERS.
The readinc; of a thermometer may vary many degrees at one and the
same place and time, according to the mode of exposure. If bung with-
out protection, it will be unduly heated in the day-time, and unduly
cooled at night, and if inside a tent it will probably not show the full range
of the air's temperature. If, then, circumstances admit of the traveller's
taking with him a light screen for the suspension of the maximum and
minimum thermometers and the hygrometer, it is very desiral)le to do
so. The accompanying figuro represents such a screen, 5 ft. high,
suitable for countries where the winds are moderate or liglit, such
as are most tropical countries. It is constructed of bamboos or rods of
light wood, cords and canvas, which may easily be made up before
starting, and It is easily renewed or repaired. The canvas roof should be
trijjle or quadriiple according to the thickness of the material. Such a
screen will atibrd sufficient protection at night, or even in the day, if set
up in the shade, and it will throw off rain ; but iu the sun it will require
a thick mat as an additional iirotection on the roof. A light frame between
the uprights carries the instruments.
The chief advantage of this form of screen is its portability, and it is
suitable only for camp use. Wherever an observatory can be set up for
some weeks or months, the best form of screen is a louvrcd box, with a
METEOKOLOGY AND CLIMATE. 337
double roof, having an air-space between the roofs. This should be fixed
to four posts firmly planted in the ground ; the door, which should also
be louvred, opening on the side away from the sun.
The best form of rain-gauge is that known as Symons', with a receiving
funnel 5 in. in diameter. But if it be important to reduce the size
to the lowest limit for the sake of portability, a large bottle with a funnel
of 3 or even 2 inches diameter screwed on the neck will give fairly good
results. The size of the bottle will depend on the average heaviness of
the rainfall in the country visited. In the tropics during the rainy
season 3 or 4 inches in the twenty-four hours is by no means un-
frequent, and sometimes as much as this may fall within an hour, and 35
inches in a single day have been recorded on the plains of Northern India ;
but in most extra- tropical countries 2 inches in twenty-four hours is an
unusual fall. A bottle or other receiver that will hold C inches of rainfall
will suffice in most places, the contents being measured and emptied once
a day ; and, in the event of any fall exceeding this, care must be taken to
measure it more freqiiently. The funnel, if not exceeding 3 inches diameter,
maybe of brass. If larger, its mouth should be strengthened with a stout
brass ring, to prevent deformation. Any alteration of its form diminishes
its size, and therefore falsifies the record. The glass in which the rainfall
is measured must be graduated to suit the size of the funnel; but, incase
of accident, any truly graduated glass, such as an ajjothecary's 2 oz. or
4 oz. glass, may be substituted, and the rainfall being recorded as fluid
ounces, drachms, &c., may be converted into inches by a simple calcula-
tion, the diameter of the funnel being known.
The most convenient form of barometer for travelling is the pocket
aneroid. Those by the best makers give fairly constant readings, but no
aneroid can be depended on as unchangeable. It should be compared
with a standard mercurial barometer as late as possible before starting,
and recompared, as often as opportunity may offer, with any mercurial
barometer, the correction of which to the Kew or some other acknow-
ledged standard is known. Comparison with an uncorrected mercurial
barometer is of little use, since all mercurial barometers have some
small scale error, and some a large error. The comparison should be
made with the reading of the mercurial barometer, corrected for tem-
perature (to the freezing-point), and reduced to the standard value,
and the correction thus determined should l>e applied to all tlie aneroid
•2 A
338 H1NT8 TO TRAVELLERS.
leadings. An aneroid should not require any temperature correction,
if compensated.
Any correction thus determined holds good, however, only so long as
the instrument is exposed only to temporary variations of pressure, the
average pressure being not greatly changed. It has been ascertained by
Mr. Whymper that when an aneroid is subjected to a great reduction or
increase or decrease of pressure, and so kept for many days, its error
gradually augments, until it may become two or three times as great as
when the change was first effected. If, therefore, the traveller remains
long on a high plateau or mountain range, his aneroid will continue
falling quite independently of any further reduction of atmospheric
pressure ; and in like manner when after such sojourn he returns to low
altitudes, some weeks will elapse before the instrument recovers its
original average readings at the higher pressure, and it may be found to
have imdergone a permanent change. The readings of an aneroid are
therefore to be depended on only so long as it has not been exposed to
great differences of pressure for prolonged periods.
Barometric observations. — Before reading a mercurial barometer, care
must be taken that the instrument is quite vertical, which will be the
case if it is suspended freely from the top, or in gimbals on an axis 3 or
4 inches above its centre of gravity. It must have a uniform tem-
perature, to ensure which it ought to be suspended in the shade for at
least half an hour before reading. The mercury-level of the cistern
must be adjusted to the fiducial point at each reading, and in setting the
vernier the eye must be exactly on the level of the top of the column
to avoid errors of parallax. The reading of the thermometer attached
to the barometer must always be noted simultaneously with that of
the scale and vernier, as this is required to correct the reading for
temperature.
In taking readings of an aneroid, the instrument should always have
the same position, preferably the horizontal, and the eye must be verti-
cally over the index. If it has been at rest for some time previous to
reading, the case shoidd be gently taj^ped with the finger before reading.
The variations in the readings of a barometer transported from place
to place in the course of a land journey ai-e influenced both by changes of
elevation, and by those of the weather, the effects of the former being, in
general, much more considerable than those of the latter. If, then, the
METEOEOLOGY AND CLIMATE. 339
barometer is used for the puriDose of ascertaining elevation, no'great
accuracy can be expected, unless the effect of weather-changes can be
ascertained and eliminated, and this is only possible, even in an approxi-
mate degree, when its readings can be compared with those made simul-
taneously at some not very distant station of reference, the elevation of
which is known. And, on the other hand, unless the elevation of the
station of observation is accurately known (or the average barometric
reading of the site and season of the year) the barometer is useless as a
weather glass, except in so far as any conclusion can be based on the
simple fact of a rise or fall between consecutive readings at the same
place. Hence, in travelling through a country far distant from any fixed
observatory, the barometer is used chiefly for hypsometrical purposes,
and in computing elevations it is necessary to assume a mean barometric
value at the sea-level. This is generally taken at 30 inches ; but this
assumption sometimes involves a large error, which may seriously vitiate
the computed result. Especially is this the case in the interior of great
continents, particularly Asia, when the mean sea-level value of the
atmospheric pressure in July is more than an inch below the mean of
January, an amount of change which would be produced by an ascent
through about 1000 feet.
In such cases it would much improve hypsometrical determinations if,
instead of assuming the constant value of 30 inches for the sea-level
datum, its value be taken from a barometric chart showing the average
distribution of atmospheric pressure for the month of observation in that
part of the world. Several such charts have now been published, the
latest and probably the best being those drawn up by Professor Hann, and
published in the recent edition of Berghaus's 'Physical Atlas.' These
include charts of the average distribution of pressure for January and
July, and since these represent the extreme phases of the anniial oscilla-
tion, the values for other months obtained by interpolation will involve
only a small error in most parts of the Northern Hemisphere. But for
tlie interior of Australia, Africa, and South America there exist no data
for compiling such charts, and the best assumption that can be made is
that, about the time of the equinoxes, the sea-level pressure on these con-
tinents is probably about the same as in the same latitudes on the ocean,
two- or three-tenths lower in the heart of the country in Januai-y
(midsummer) and as much higher in July (midwinter).
2 A 2
840 HINTS TO TRAVELLERS.
Between tlic tropics, tlie oscillations of the barometer with irregular
changes of weather, excc])t during the passage of a cyclone, are compara-
tively small ; in general not exceeding from one- to two-tenths above or
below the average (equivalent to one or two hundred feet of elevation; ;
l)ut in the temperate and arctic zones they often amount to upwards of
an inch, and in these parts of the world barometric determinations of
heights from isolated readings are siabject to uncertainty thi'ough a large
range of possible error, unless the simultaneous observations of fixed
stations, laid down on weather charts, supply the means of correction.
These oscillations are greater in winter than in summer. The longer the
period over which the observations extend, the smaller will be the pro-
bable error of the computed result.
In all parts of the world, except perhaj^s in the neighbourhood of the
poles, the barometer has a regular daily oscillation, independently of the
weather. Except, however, in the tropical and sub-tropical zones (say
between 40^ N. lat. and 30° S. lat. over coutiueuts and within narrower
limits on the ocean), this oscillation is too small to need special attention
in hypsometrical determinations, especially if the far greater irregular
oscillations are unknown. In the troiDics, however, it is both absolutely
and relatively more important, and should be taken into account, both in
computing elevations and in interiDreting the barometric changes with
reference to the weather. The barometer rises from 3 or 4 a.m. to
between 9 and 10 a.m., then falls to between 4 and 5 p.m., rises again to
10 P.M., and again falls till about 3 a.m. Where greatest, as in Southern
India, the fall from the forenoon to the afternoon amounts to about -^
of an inch ; the other changes are less, but the exact amount and also
their relative amounts vary not only with the latitude, but under the same
latitude from place to place. In valleys between mountains, the midday
fall is greater than on plains, and on mountain j^eaksand crests consider-
ably less, and in these latter positions the barometer stands higher before
nliduight than at any other epoch of the twenty-four hours. Some data on
this head are given in the section on hyiisometry. On the sea, the night
and day oscillations are more nearly equal than on laud.
Tcmperatnre observations. — The readings of thermometers are under-
stood to show the temperature of the air, and the sling thermometer does
this very nearly, even in the sunshine, and very accurately in the shade.
But thermometers suspended and at rest are affected by radiation from
METEOROLOGY AND CLIMATE. 341
all objects round about them, and these may raise their temperature in the
daytime above that of the air, and unduly lower it at night. They must
in any case be fully screened from the sun and the sky, and from any
strong reflection of sunlight, and at the same time the air must be allowed
to pass over them freely. Inside a tent, the night temperature will generally
be higher than that of the air outside ; in the daytime it may be higher
or lower, according to circumstances, but it will rarely be the same. The
use of the screen, describe d above, is to afford a tolerably uniform exprsure,
and a sutRcient, but not excessive, protection. In order to ascertain how
far it fulfils this purpose, simultaneoiis readings should sometimes be
taken with the sling thermometer and the suspended thermometers,
and the two comj^ared. The results of such comparisons should always
be entered in the register.
The thermometers should always be suspended at the same height above
the ground. In the warmer hours of the diiy, when the sun is shining,
the ground and the air in contact with it are much warmer than that
a little distance above it, and the temperature decreases rapidly within
the first few feet; while at night time, and especially on clear nights,
the reverse holds good. The u.?e of the screen eus^ures uniformity in this
respect also.
Readings of the self-registering thermometers can be made only in
camp or at a halting station. In settled weather, and almost invariably in
tropical countries, the lnwest temperature of the twenty-four hours occurs
shortly before simrise, and the highest from one to three hours after noon.
As the maximum and minimum temperatures are understood to be the
extremes of the twenty -four hours, implying that tlie instruments have been
exposed throughout this period, if such is not the case, the fiict should
be noted against the reading, together with the hours of exposure.
In addition to the maximum and minimum temperatures, it is desirable
to take readings of the actual temperature at certain fixed hours. The best
hours are either 6 a.m. and 2 and 10 p.m., or 7 a.m. and 2 and 9 p.m., these
being the hours that are very generally observed at regular observatories,
and having the further advantage that the arithmetical mean of the
three readings is, on an average, very nearly the true mean temperature
of the day. But whatever hours are selected should be regularly adliei'cd
to, so that the readings of different days may be comparable with each
other.
342 HINTS TO TRAVELLERS.
In camp, tlio air temporatnrc reading may be taken from the dry bulb
of the hygrometer or the sling thermometer, or botli. On the march, the
hitter instrument alone should l)e used.
The use of the sling thermometer is as follows. Each thermometer has
a strin'g a couple of feet long attached to a glass ring at the upper end of
tlie tube ; tlie end of this being secured by a few turns round the finger,
the instrument is swung round a dozen times or so and rapidly read off.
It is then again swiing and the reading repeated, and so on, until the read-
ing remains constant, and this final value is entered in the note-ljook. It
is best to select shade for this purpose, but it is the peculiar advantage
of the sling thermometer that its indications are but little affected by
the sun.
The temperature of the air is much infliicnced by the character of the
site ; and this should always be noted in the register. On hill summits
and hill ridges the diiirual range of temperature is less than on a plain,
and considerably less than in a narrow valley. Hence at night, and
especially in the winter, it is often warmer a few hundred feet up a hill-
side than at lower levels. More particularly is this the case in a still
atmosphere. In certain mountainous countries, the winter temperature
in a valley may be no higher than at 5000 feet above it, and lower than
at all intermediate elevations. With these exceptions, the temi^erature
generally decreases with elevation, but the ratio is very variable. On
moifntains the average rate of decrement is 3° in every 1000 feet,
but in rainy weather it is often less than this, and in hot, dry weather,
especially if a Fohn wind is blowing, it may be as much as 4" or 5° in the
1000 feet. On plains and table-lands it varies as a rule between 2' and 3"^
per 1000 feet.
In respect of temi^erature the most important elements of climate
are : —
1st. The mean temperature of the year, and of each month.
2nd. The annual range of temperature, which may be expressed either
as the difference of the highest and lowest readings in the
year or that of the mean temperatures of the warmest and
coolest months.
3rd. The extreme temperatures of each mouth and their difference, i.e.,
the monthly range.
METEOROLOGY AND CLIMATE. 343
4th. The mean daily range, and the greatest in each month.
5th. The variability of temperature, which, in the case of observations
extending over short periods, is best shown by the amount
of the mean change from day to day, i.e., the average difference
of the mean temperatures of consecutive days.
Most of these data express conditions that have an important influence
on vegetable life and almost equally so on human health and comfort.
The real annual and monthly mean temperatures can of course be
ascertained accurately only from many years' registers. But, in most
places, an approximation to the mean annual temperature may sometimes
be obtained by taking the temperature of perennial springs, fed by
percolation from the surface (not mineral springs).
In connection with non-periodical changes of temiJerature, it should
be noted how they are related to changes of wind. This relation may
be different at different seasons. Thus, in Northern India, the West and
North-west winds are tlie cooler winds of the winter months, but the hot
winds of the spring and summer.
Humidity observations.- — The observations of the dry and wet bulb
thermometers may be made either with the hygrometer suspended in the
screen, or with the sling thermometers, as already described; the wet
bulb being swung slowly, and, if necessary, re-wetted between each
swinging. The hours of observation should be the same as for tempera-
ture; and the mean of the three values comj)uted from each pair of
observations separately will be very nearly the true mean of the twenty-
four hours.
In a calm atmosphere some care is necessary to obtain trustworthy
readings of the wet-bulb thermometer. A single thickness of muslin
should be fitted closely over tlie bulb, and both it and the wick that
supplies it with water should be quite clean, and especially free from
grease, in order that they may take up the water readily and remain wet,
however rapid the evaporation. The softest and purest water obtainable
should be used, since hard water gradually deposits a stony encrusta-
tion, which is removed with difiiculty. The air must not stagnate
aroiTud the hygrometer, since, in still air, the wet bulb gives too high a
reading.
From tbe simultaneous readings of the dry and wet l)ulb thermometers
.')44 HINTS TO TRAVKLLKRS
(duly corrected for the errors of the instruments) the liumidity of tlie
air is deduced by a simple computation. It may he expressed in four
different ways. First, as the pressure of the vapour present in the air
(expressed in decimals of an inch of mercury) ; second, as the weight
(grains) of vapour in each cubic foot of air ; third, as the dew-point of
the air, or that temperature at which the vapour would begin to condense ;
and fourth, as a percentage of the quantity that would saturate the air
at the observed temperature. The first three express the ahsohife, the
last the relative humidity. The last is perhaps most important in relation
to the weather, and as affecting vegetation and bodily comfort.
The ijressure of the vapour in the air maybe computed liy the following
formula, in which t and t' , are the corrected readings of the dry and wet-
bulb thermometers respectively, / the tension of saturated vapour at
temperature t, to be taken from the table at the end of this section, and
h the height of the barometer. For this last, a rough approximation (to
the nearest inch) is sufficient. For wet-bulb temperatures above 32°,
the formula is
and for those below 32^^
0-480(^-0,
^-•^-"1130-f ^''
0-480 (<-0
^ ~'~ 1240-2 -<' "'
F is the tension of the vapour present in the air. This being computed,
the relative humidity is given by the formula
Numerous tables are published by which the observer may be saved
the labour of computing both these values.
Professor Nordenskiold is of opinion that in Arctic climates, with the
temperature far below the freezing-point, the ordinary hygrometers do
not give trustworthy results. When exposed in the usual way in a
louvred box, it is impossible to keep the case clear of snow, and thus
the air, which may have been originally quite dry, must here be saturated
with moisture from the evaporation of the snow. He recommends, there-
fore, that in order to determine the true humidity, future travellers to
METEOROLOGY AND CLIMATE. 345
these regions should weigh tlie water which a given measure of air con-
tains, by passing a measured quantity through tubes containing some
desiccating substance, such as dehydrated sulphate of copper or i^umice
soaked in sulphuric acid. This requires a delicate balance, in addition
to the aspirator and absorption tubes, and can, of course, only be carried
out conveniently either on board a ship or at an observatory temporarily
established on land, but it has the advantage that, by means of a tube of
sufficient length, the air to be tested can be drawn from any required
height above the surface, at such a height as to be above the influence
of the snow dust that whirls about near the ground surface. The use
of this apparatus, which is very simple, should be learned in a physical
laboratory.
The humidity of the air varies with small changes of site and elevation
even more than the temperature, especially in the neighbourhood of
sheets of water, swamps, etc. In moimtain tracts, with greater changes
of elevation, the relative humidity, as a rule, increases gradually with the
height, while the absolute humidity generally decreases. In settled
weather the relative humidity is greatest when the temperature is lowest
(viz., just before sunrise), and lowest at the hottest hours of the day,
varying inversely as the temperature. The absolute hiimidity is highest
in the early afternoon in damp climates, in dry climates usually in the
evening. It often varies with the wind direction in a very marked
degree, even in the interior of continents, and all such changes should
be especially noted.
Plain, snow, hail, dew, t&c. — The rain-gauge must be exposed in an
open place, as far as possible from trees, and not too near a tent. The
aperture of the funnel should be quite level and about 1 foot above
the ground. For ob\aous reasons it is desirable to siirround it with
a temporary fence, at a distance of at least three feet when not
exceeding three feet in height. A gauge of 5 inches diameter and
upwards will serve to collect a small fall of snow, and, when melted,
the snow water is measured as rain ; but with a heavy fall the funnel
soon becomes choked, and collects no more. In this case, if the gauge
has a cylindrical receiver of the same diameter as the funnel, it may be
inverted over the snow, where not drifted or otherwise disturbed, and
pressed down so as to cut out a cylindrical mass of the thickness of the
sheet, which may be melted and measured in the usual way. Failing
34G HINTS TO TRAVELLETiS.
this, the thickness of the snow, wliere undisturbed, may he gauged
with a 2-foot rule, and each foot of snow counted as 1 inch of
rainfall. This ratio is approximately valid, when the measurement
is taken immediately after the fall, but oven then is only a rough
approximation.
In the case of hail, the form, size, and internal structure of the
hailstones should bo noted, and, if possible, sketches should be made
of some of the largest as soon as possible after their fall, and before
they have had time to melt. The forms of hailstones are very
various, and their mode of formation is still far from being satisfactorily
explained.
The hours of rainfall, &c., should be noted in the register. In the tropics,
there is often a very decided tendency to rain at certain hours of the day
or night, differing at different seasons of the year. The time of least
frequency is the hour or two before midnight. The quantity that falls in
short intervals of time, such as an hour or less, is also a very marked
feature of certain climates.
In nearly all parts of the world there is more rain, snow, hail, &c., at
certain seasons of the year than at others, and in most tropical countries
this a]inual variation is very marked. Wherever this is the case, the
seasons of ploughing, sowing, transplanting, &c. crops, are determined
by that of the rainfall, and where there is more than one rainy season
certain crojjs are special to each. It should always be ascertained, if
possible, what are the usual seasons of rain and their duration ; also
what characteristic changes of wind accompany rain and dry weather
respectively.
Mountain ranges exert a very important infiuence on the distribution
of rain. Whatever be the characteristic direction of the damp wind, the
rain is heaviest on the windward face of the range and the plains at its
foot, and often entirely restricted to them ; the quantity and frequency
of the falls increasing with proximity to the mountains, and in the case
of lofty ranges reaching a maximum at a certain elevation, above which
it decreases. In India and Java this elevation is between 3000 and
4000 feet; in England apparently about 1500 feet. Wherever possible,
it is important to ascertain this height, which may be approximately
indicated by the character of the vegetation. In snowy ranges the
height above which snow remains unmelted throughout the summer
METEOROLOGY AXD CLIMATE. 347
should also be ascertained, bearing in mind that glaciers often descend
much below this limit.
The occurrence of dew should always be noted in the register. Its
quantity may be roughly estimated as light or heavy, or it may be
measured by exposing a weighed mass of dry wool or cotton-wool spread
over a surface of definite dimensions, and re-weighing after exposure;
but this requires a delicate balance, and the observation is of a kind more
suited to the means and appliances of a fixed observatory than to those of
the traveller.
Windfi. — The direction of the wind may be easily obtained by a pennant
or flag, the drift of smoke, or better than either, by observing the move-
ment of low clouds with a compass. In order to do this accurately,
select some prominent object, such as a tree-toji or the top of the tent-
pole, and take up a position such that the apparent movement of the
cloud is either directly downwards towards it or directly up from it. Then
the direction of the tree or pole as taken by the compass is that towards
which the cloud moves in the former and from which it travels in the
latter case. Generally the surface-wind blows from a point a few
degrees to the left of that indicated by low clouds in the Northern
Hemisphere ; to the right in the Southern Hemisphere. At night the
movement of the clouds across the face of the moon affords a good means
of observation.
A very important class of observations, which should be recorded as
often as opportunity may serve, is the movements of the high cirrus or
feather cloud. This may be oliserved in the same way as that of the
lower clouds ; but the observation takes longer, since, owing to the great
elevation of the cirrus, its apparent movement is very slow. Tliese clouds
show the movements of the atmosphere at elevations of 30,000 feet and
upwards— movements which are much less variable than those of the
surface winds ; and a knowledge of the directions prevalent in different
parts of the world is much required for determining the greater and more
])ersistent movements of the atmosphere.
Another method of observing the movements of clouds, both high and
low, with ease and great accuracy, is by using a portable nephescope.
This consists of a plate of thick glass, about 1 foot in diameter, having
two lines engraved across its siirface, and rubbed in with white paint, to
indicate the four cardinal points. The glass is blackened on the back
348
HINTS TO TRAVETJ.ERS.
and mounted in a light brass frame, which is supported by three adjustable
screws for levelling. A small pocket spirit-level is carried with the
instrument, and also a small leaden disk with a vertical pin about an inch
higli fixed to its margin. To observe with this instrument, the mirror is
levelled and adjusted in azimuth, and, a small cloud having been selected,
the observer takes up a position such that its reflection coincides with
the cross-lines in the centre of the mirror. The disc is then placed on
the mirror so that the point of tlie pin is between the eye and the cross.
When suificienfc time has elapsed for the cloud reflection to have
travelled some little distance across the mirror, the observer takes up
the same position as at first, which the pin and cross-lines enable him to
do accurately. The direction in which the image has travelled across the
mirror is accurately that of the cloud's movement.
The force of the wind on land may be estimated as, 1, Calm ; 2, Light ;
3, Moderate ; 4, Fresh ; 5, Strong ; 6, Gale, and noted in the corresponding
numbers. At sea, a more definite scale extending to 12 numbers, known
as Beaufort's Numlers, is employed, but this is hardly applicable on land,
except on the coast. Their approximate values in miles per hour are as
follow : —
0. Calm .
1. Light air
2. Light breeze
3. Gentle breeze
4. Moderate breeze
5. Fresh breeze
6. Strong breeze
7. Moderate gale
8. Fresh gale .
9. Strong gale .
10. Whole gale .
11. Storm .
12. Hurricane ,
to 5 miles per hour
6 to 10 „
11 to 15 „
16 to 20 „
21 to 25 „
26 to 30 „
31 to 36 „
37 to 44 „
45 to 52 „
53 to 60 .,
61 to 69 „
70 to 80 „
80 miles and upwards per hoiir.
At most places, the winds undergo a more or less regular variation in
the course of day, and at some this is sufficiently marked to be obvious
to the casual observer. It may affect the rate of movement or the
direction, or both. All such instances are worthy of being noted, together
METEOROLOGY AND CLIMATE. 349
with the hours at which the changes occur, the local geograi)hical features
that influence them, and the character of the weather when they are
most developed, and when they are suppressed. The traveller should
also ascertain what winds are most prevalent at each season, and their
character as damp or dry, hot or cold.
At some localities, chiefly in the neighbourhood of mountain ranges, very
strong but dry winds, sometimes accompanied with fine weather, blow at
certain seasons of the year, but only in certain states of the atmosphere.
Such are the Fohn in Switzerland and the Tyrol, the Bora in the Adriatic,
and the Mistral at the mouths of the Ehone and on the northern coast of
the Gulf of Genoa. The first of these is a warm, dry wind, the second
much less warm, and the third, though dry, very cold. The Fohn and the
Bora blow down from mountains, and are heated more or less in virtue
of the compression which the air undergoes in descending from the higher
to the lower level. There is reason to believe that similar strong winds
are exi^erienced in the neighbourhood of other mountain chains in tem-
pei'ate and Arctic climates, and indeed such have been described both in
Greenland and the Caucasus. The Mistral, which blows in the winter and
spriug, owes its stormy character to the juxtai:iosition of the cold plains
of Central and Southern France and the relatively warm Mediterranean
Sea ; and it is restricted to the lower course of the Rhone and the coasts
of the Gulf of Genoa. A stormy wind of the opposite character blowing
from the cooler sea to the heated land is common in the spring in the
north of the Bay of Bengal. All such cases should be noted by the
traveller.
State of the sky and atmosphere, Cloud, &c. — The cloudiness or serenity
of the sky is most conveniently recorded by estimating the ijrojjortion that
is covered with cloud as so many tenths of the exi^anse included within G0°
of the zenith, or within two-thirds of the total distance between the zenith
and the horizon. The zone within 80° of the horizon is excluded, since
distant clouds are foreshortened in plan, and cannot be estimated on the
same scale as those overhead. The quantity is recorded in the numbers
to 10, zero indicating a cloudless sky, and 10 one entirely overcast. In
this estimate, clouds of all kinds and at all elevations arc included indis-
criminately, and it is desirable, therefore, at the same time, to note the
leading characters of the clouds, since certain forms are characteristic of
fine weather, while others portend unsettled weather. This distinction is
350 HINTS TO TRAVELLERS.
taken as tlie basis of the scheme of cloud classification drawn up by
Messrs. Hildebraudsson and Archibald, which is as follows : —
a. Discrete tending to rounded forms 8. Extended and sheet-like forms
(^principally in dry weather'). (rainy weather).
A. Highest clouds, mean height 30,000 feet.
1. Fibre cloud \_Cirrus or mare's 2. Thin cloud veil \_Oirro stratus'],
tail].
B. Medium elevation 13,000 to 20,000 feet.
3. Small globular cloudlets, shining
white like silk, 20,000 feet [Cirro- 5. Thicker ash-coloured, or bluish-
cumulus, mackerel sky]. grey sheet, 17,000 feet \_Strato-
4. Larger globular, like white wool, citrics].
13,000 feet \_Cu7aido-ci7Tus'].
C. Lower clouds, 5000 to 7000 feet.
6. Great rounded masses or rolls of 7. Ragged sheets of grey cloud from
grey cloud [_Strato-cuimdus']. which rain commonly falls
[Nimbus].
D. Clouds in ascending air currents.
8. Heap cloud [Cumulus]. Summits at 6000 feet. Bases at loOO feet.
9. Storm (thunder) clouds [C«?/mZo-/i{m6ws]. Summits 10,000 to
16,000 feet, bases 4500 feet.
E. Elevated fogs. Below 3500 feet [Stratus].
The elevations given are furnished by measurements made in Northern
Europe, and would probably differ in other latitudes, being greater in the
tropics. But Mr. Abercromby finds, as the result of his wide experience
in different parts of the world, that cloud forms are much the same every-
where, save only that some forms are more prevalent in lower and others
in higher latitudes.
Fogs, as is well known, are restricted to damp climates and cold
weather; but sometimes they present peculiarities that are worthy of
METEOEOLOGY AND CLIMATE. 351
attention. A remarkable instance of tlie kind occurs in Assam, where,
in the cold season, the atmosphere often remains perfectly clear till about
half an hour after sunrise, when, in the course of a few minutes, everything
is obscured by a thick fog, which may remain undissipated for some
hours. The writer is not aware of a similar phenomenon having been
recorded elsewhere.
In some very dry countries where fogs are unknown, the atmosphere is
nevertheless frequently or even constantly obscured by a more or less
dense haze up to heights of many thousands of feet. Such is the case in
the dry season in Northern India, and in the almost rainless region of
Yarkand and Kashgar, it is described as being constantly so thick that,
according to Dr. Henderson, hills only five miles distant are barely visible ;
and Mr. Shaw also states that the Pamir mountains, at the distance of
twelve miles, appear to be a distant range of which the outline only is
distinguishable. On the other hand, in the almost equally dry salt desert
{Kavir) of Persia, the atmosphere is usually remarkably clear. There can
hardly be much doubt that the haze consists of fine dust, but the conditions
which determine its j)revalence in some countries and its absence in
others, deserve more attention than they have yet received.
Storms. — In the case of storms, we must distinguish between temporary
squalls (thunder-storms with or without hail, dust-storms, &c.), such as
occur chiefly in hot summer weather in all j^arts of the world, and especially
in the tropics, and those more extensive disturbances, which are inarked
by a more or less considerable depression of the barometer, which often
travel some thousands of miles over land and sea, and on tropical seas
develop into those formidable and destructive storms, long known as
hurricanes in the West Indies, as typhoons in the China seas, and
generally during the last thirty or forty years as cyclones. Tornadoes or
whirl-winds, cloud-bursts and water-spouts which, within restricted
limits, arc even fiercer and more destructive than tropical cyclones, ajipcar
to be essentially related to the former in their mode of origin, though the
whirling of the air, which is one of their chief characteristics, has led
many writers to class them with the latter; but the blizzards of the
Xorthern American States and their Asiatic counterparts, and the Buran
or Purga of the Siberian tundras, are a severe winter form of the storms
of the cyclonic class.
Thunder-squalls appear to be local eddies of the atmosphere, but
352 HINTS TO TRAVELLERS.
there is yet much to be learned respecting their mode of origin, and tlic
circumstances that give rise to them. In many cases, and especially
those of the more severe forms, they appear to be determined by the
juxtaposition of a cold and dry with a warm and damp air current.
Such has been shown by Lieut. Finlay to be the condition that always
accompanies the destructive tornadoes of the United States, and it
l)robably holds good also in Bengal, where, however, tornadoes are com-
paratively infrequent. The nor -westers of Bengal and the dust-storms
of North-western India are also probably due to the existence of a dry
and comjiaratively cool air current above, and a warm damp atmosphere
at the earth's surface. These and similar squalls of the temperate zone
are preceded by strong, sometimes violent, gusts of wind blowing outwards
from beneath the storm-cloiad, and also by a rapid rise, followed by
irre^^ular oscillation of the barometer. Hail sometimes falls in these
squalls, as a rule from the front part of the storm, succeeding the gusts,
and in these cases a peculiar sound is often heai'd on the approach of the
storm, which is generally attributed to the hurtling of the hail-stones in
the storm-cloud. The formation of hail is far from being satisfactorily
explained. The most probable hypothesis is that of Professor Ferrel, viz.,
that there is in the stjrm- cloud a violent eddying uprush of air of the
nature of a tornado, and that the hail-stones formed by the dynamic
cooling and condensation of the vapour thus carried up, after being
thrown off from the summit of the eddy, are caught up again and again
and enlarged by further condensation, until they attain such a size as to
escape the indraught around the vortex. Observations on the tempera-
ture and humidity of the air, taken at short intervals (such as iive minutes)
on the approach of a thunderstorm, and those of the general and internal
movements of the storm, that will help to throw light on the genesis of
hull, may be of much value. A similar remark ajiplies to the rarer
phenomena of water-spouts and tornadoes. The direction of their
internal movement shoidd also, if possible, be noted, wliether clockwise or
anti-clockwise.
In the case of the more extensive cyclonic storms, the extension of our
present knowledge is to be looked for chiefly from the greater development
of the system of weather charts. These of course cannot be constructed
from the isolated observations of a traveller, but it may sometimes happen
that such observations may furnish a useful link in the evidence elsewhere
METEOROLOGY AND CLIMATE 353
furnished by permanent observations or by shi^js. Where the ravages of
a cyclone are visible in fallen trees or other objects it may be useful to
note the compass direction of their fall, as an indication of the wind
direction when strongest. And in the neighbourhood of the sea-coast, if
the storm has been accompanied by a storm-wave, which has flooded the
land, the height of the inundation should be ascertained from the marks
left on trees, buildings, &c.
S^yerJal observations — There are many subjects connected with meteor-
ology and the physics of the atmosphere, for the investigation of which
other parts of the world aiford more favourable conditions than are to bo
found in our own islands. Many of these, however, demand not only
prolonged residence at the place of observation, but also a familiar ac-
quaintance with physics and methods of i)hysical ex2)erimentatiou, siach
as can only be gained by long study and practice ; and any notice of them
would be beyond the scope of these hints. But there are one or two
subjects of inquiry, to which, although somewhat special, travellers may
contribute valuable information, and which demand nothing more than
some time and attention, and such ordinary precautions as are implied
in the proper use of even the simplest instruments.
Among the more important of these are the sun's heating-i^owcr, the
temperature of the ground, and the diurnal variations of air-temperature
and humidity, and the atmospheric pressure. On each of these a few
suggestions will be offered.
The absolute measurement of the heat received from the sun, i.e. its
quantity in terms of heat-units per second or other units of time, is a
problem that has hardly yet been satisfactorily solved. Several forms of
actinometer have been devised for the purpose, but it is at least doubtful
whether any are free from serious error, while their use requires
an amount of skill that demands long training; but even a good
relative measurement, such as may be made with simjile instruments,
is of much value, and may be undertaken by any one who will devote
some little pains to the subject. Especially is it desirable to oljtain
relative measurements at different elevations on mountains, and at
different hours of the day; and as an element of climate the datum is one
of great importance. For this purpose, the requisite instruments arc two
mercurial thermometers in vacuum tubes, the one having the bulb coated
with lamp-black, the other uucoated. With this exception, the instru-
2 B
854 HINTS TO TRAVELLERS.
ments should be exactly similar in all respects ; the bulbs and their
enclosures of the same dimensions, thickness and materials, and
exhausted to the same degree, to as high a vacuum as possible. They
should not be self-registering, hut made to read as ordinary mercurial
tlicrmnmcters, and they should be verified (as complete iustruments) and
furnishod with tables of corrections. They should be exposed on a stand
about i foot high, being about G inches apart, the Indbs free of the stand,
so that they may be equally affected by all objects around. The instru-
ments should be wiped with a soft cloth before exjiosure. An universal
sun-dial is an useful adjunct.
The observations will consist of simultaneous readings of the two
instruments, and a reading of the air temperature as shown by the
ordinary shaded thermometer. Tlie readings should be taken at apparent
noon (as given by the ' Nautical Almanac,' or by a sun-dial truly adjusted
for the magnetic variation, and at equal intervals, one, two hours, &c.),
before and after, provided the sky is clear. The depth of the sky tint
should be noted at the time of observation, and also the existence of haze
and thin cirrus cloud, and the movement of the latter whether towards
the sun or otherwise. These facts may be recorded according to the
following notation, devised by Mr. Hennessey for the guidance of the
actimometric observers at Leli : —
A — signifies a perfectly clear sky, or, if small patches of cloud be
visible, they are not within 50° of the sun.
B — signifies that small patches of cloud are occasionally seen to rise,
and float generally towards the sun ; that they become invisible
in certain positions not less than 30° from the sun, but that
their tracks if continued would pass well clear if the sun.
C — has the same meaning as B, with the exception that the tracks
point to the sun.
(I — means no haze.
7, — means that haze can be seen in the far distance, but only along a
portion of the horizon.
c — means that haze is visible all round the horizon, or at any rate in
opposite directions, but not overhead.
The numbers 1 to 4 are used to indicate blueness of the sky : 4 stands
for deep blue, and 1 for pale blue-white, with 2 and 3 for inter-
mediate tints.
METEOROLOGY AND CLIMATE. o55
The temperature of the ground surface may be taken with an ordinary
mercurial thermometer (duly verified for error), laid on the ground
slightly inclined, the bulb just immersed in the surface layer of soil,
but not quite covered ; this may be read just before sunrise and about
1 P.M., these being the times of minimum and maximum temperatures >
also, if convenient, at intermediate hours ; or maximum and minimum
self-registering thermometers may be exposed in like manner, but in this
latter case, the minimum (spirit) thermometer must be removed during
the daytime, or it will probably burst with the high temperature of the
heated ground. The spot for these observations must be unshaded at all
hours of the day.
Temperature observations of the ground beneath the surface are
valuable only when they can be continued for at least a twelvemonth
at the same spot. In such cases it is desirable to obtain observations
from a dei^th of about 3 feet 6 inches, which is about the limit, below
which the diurnal variation becomes insensible, though, it must be
remarked, this limit must vary with the conductivity of the soil and
the amplitude of the daily variation at the surface. A good arrange-
ment for obtaining such temperatures is to sink a square wooden tube
to the required depth, leaving the end jDrojecting 6 inches above tlio
surface, the upper end being covered witli a loo-^ely-fitting wooden cap
In sinking the tube, care should be taken not to disturb the ground
around, except on one side, and on that side not to a greater width than
is necessary. The thermometer should have its bulb protected by a
copper shoe, and should be sunk in the lower end of a wooden jjlug
nearly as long as the tube, and nearly filling it. If the thermometer is
merely suspended by a cord or wire, leaving the greater part of the tube
iinfiUed, the circulation of air inside the tube will vitiate the observed
temperatures. A tliermometer mounted in the way described can be
withdrawn and read without suffering any change, and it can then be
replaced and left till the next reading. One reading a day, at a fixed
hour, will suffice.
It is often stated that the mean annual temperature of the ground at
any place (or its -temperature at such a depth as to be just below the
limit of any annual oscillation) is also the mean temperature of tlio
atmosphere, excepting, of course, in the neighbourhood of hot springs,
of active volcanoes, and similar disturbing causes. But this is by no
2 B 2
350 HINTS TO TRAVELLERS.
means always the case. It has been found that everywhere in India
the ground temperature exceeds tliat of the air by amounts varying from
8° to G", and it is at least probable that, to some extent, a similar rule
holds good generally in the tropics, the excess being greater in dry than
in damp regions. For this reason, the temperature of such perennial
springs as may be assumed to have the mean ground temperature cannot
be always accepted as representing that of the atmosphere.
The observation of the diurnal variation of temperature, humidity,
and other elements, especially the barometric pressure, is a very valuable
contribution to meteorology. In tropical countries, where the diurnal
variation is most considerable, even a few days' observations will show
the leading features of the oscillation in fine weather ; but the longer the
period over which they extend, the more trustworthy is the result.
Observations may be recorded either hourly or every two hours through-
out the twenty-four hours, and, if not repeated on consecutive days, the
first and last of every set of observations should be made at the same
hour, so that each hourly set will comprise twenty-five readings, each
bi-hourly thirteen readings. These observations will necessarily reqiiire
that the work be shared by two or more observers, unless autogi-aphic
instruments are employed. The barometric oscillation will be shown
fairly well by a good self-recording aneroid, which marks the pressure
continuously on a drum driven by clockwork ; but this register should,
if possible, be controlled by the readings of a mercurial barometer about
the hours of maximum and minimum pressure. The larger self-recording
instruments are siiitable only for permanent observatories.
Tuinier A Shacwe
n
THE GLOBE FOR JULY.
100 ISO JdO 160
I 1 1 1 1 T-^-t 1 1 1 1 r ]
— ;t«)
^~ ' lio ^ ^ a& .1^ aflo"
'luvnei* (!fc Shaww
o
'lurncr AShawe
IS0BAR1C LINES AND PRI
€
Tui-iit?r <!t Sliawv
ISOBARIC LINE.S AND PREVAILING WINDS OF THE GLOBE FOR ,
o
METEOKOLOGY AND CLIMATE.
357
Table showing the Peessure of Aqueous Vapouk in inches op Mehccey at
latitude 45'^ for each degree fahrenheit from —30° to 119°.
o
Inch.
Inch.
Inch.
Inch.
Inches,
— JO
0-0099
0-0440
JO
o-i6')5
60
0-5192
90
I -4128
-2)
o"Oi05
I
0-0461
31
0-I7J8
61
0-5J79
9»
1-4578
-28
o-oiii
2
0-0482
n
0-1815
62
0-5572
92
I - 5040
-27
0'0ii7
J
0-0504
}}
0-1888
63
0-5771
9}
i'55i4
-26
0-0I2J
4
0-0527
i4
0-1964
64
0-5976
94
1-6001
-25
o-oijo
5
0-0551
35
0-204 J
65
0-6187
95
1-6502
-24
O-0IJ7
6
0-0577
J6
0-2125
66
0-6405
96
1-7017
-2J
0-CI44
7
0-0604
J7
0-2210
67
0-6630
97
1-7546
-22
0-0152
8
o-o6j2
J8
0-2297
68
0-6862
93
1-8088
-21
o-oi6o
9
0-0661
}9
0-2388
69
0-7101
99
1-8646
-20
o-oi68
10
0-0691
4''
0-2482
70
0-7347
100
1-922
-19
0-0177
II
0-072J
41
0-2579
71
0-7601
tot
1-980
-l8
0-0186
12
0-0756
42
0-2679
72
0-7862
102
2-041
-•7
0-0196
1}
0-0790
43
0-278}
13
0-8131
103
2-10}
-i6
0-0206
14
0-0825
44
0-2890
74
0-8409
104
2 -166
-'5
0-0217
15
o'o362
45
o-}ooi
75
0-8695
105
2-231
-'4
0-0228
16
0-C901
46
0-3116
76
0-8989
106
2-298
-1}
0-02J9
'7
0-0942
47
0-^235
77
0-9292
107
2-366
-12
0-0251
18
0-0985
48
0-3J58
78
0-9604
108
2-4J7
— II
0-026}
19
o-iojo
49
0-3485
79
0-9925
109
2-509
— lO
0-0276
20
0-1076
50
0-3616
80
I -0255
110
2-583
-9
0-0289
21
0-1124
51
0-3751
81
1-0595
in
2-659
-8
0-ojo}
22
0-II74
52
0-3891
82
1-0945
112
2-736
-7
o-o}i8
2J
0-1226
5i
0-4036
83
1-IJ05
• 13
2-817
-6
O-OJiJ
24
0-1282
54
0-4186
84
1-1675
"4
2-898
-5
O-0M9
25
0IJJ9
55
0-4MI
85
1-2056
115
2-982
-4
o-oj66
26
o-ii99
56
0-4501
86
1-2447
116
3-067
-J
0-0J8?
27
o'i46i
57
0-4666
87
1*2850
117
3-156
-2
0-0401
28
0-1526
58
0-4836
88
1-3264
ii8
3-246
- I
0-0420
29
0-1594
59
0-5011
89
1-3690
119
J'JiS
358 HINTS TO TRAVELLERS.
Note hy Mr. Cuthhert E. Peek.
As some travellers m<ay not be able to take luith rerjularity the series of
observations, recommended in the preceding article, a less complete form
is siibjoined which will give very valuable information with regard to the
country traversed, provid-ed the few simple conditions are carefully ful-
filled. The following instructions and a very convenient form of note-
book are published by the Eoyal Meteorological Society, '22, Great George
Street, Westminster.
Instructions to Observers at Cumatological St.\ticins.
Instruments Required.
Maximum Thermometer divided on the stem and verified.
Minimum „ „ „ „
Dry Bulb
Wet Bulb
Eain Gauge „
Stevenson Thermometer Screen.
Conditions to he Fulfilled.
Tliermometer Screen. — To be placed over grass in a freely exposed
situation.
Should never be in the shade, and must not be placed near any wall.
To be firmly mounted on foiu- stout posts, at such a height that the
bulbs of the dry and wet thermometers shall be four feet above the
ground, and the door open to the north.
The thermometers to be placed as near the centre of the screen as
possible. The most suitable arrangement is to mount the maximum and
minimum thermometers on two small uprights in front of the dry and
wet bulbs, in such a way that the scales of the latter can be seen above
the former.
METEOEOLOGY AND CLIMATE. 359
The maximum and minimum thermometers to be hung quite hori-
zontally.
The screen must be painted white, and should be repainted during the
spring of each year.
Wet Bulb Thermometer. — The bulb to be covered with a single piece of
fine muslin ; and have a conducting thread of three or four strands of
darning cotton tied in the form of a noose round the neck of the bulb
over the muslin, the ends of the thread passing into a water receptacle
through a small orifice at the top, placed about three inches from the
bulb.
Clean rain water alone to be employed.
The muslin and conducting thread to be soaked in boiling water prior
to use, and to be changed at least once a month, and more frequently if
there is any appearance of dirt or deposit.
When the temperature is below 32", the bulb to be wetted about an
hour he/ore the time of observation, so that a coating of ice may be
formed round the bulb.
Rain Oaiige. — The rain gauge to be of copper, and have a funnel of
five or eight inches diameter.
It is desirable that it have also a deep rim to retain snow.
The gauge to be placed in an open and well-exposed situation, free
from trees, walls, and buildings, and firmly fixed so that it cannot be
blown over.
The top of the funnel to be one foot above the ground, and quite level.
Observations.
The observations to be made once daily at 9 a.m. local time.
After the readings have been entered in the note-book, the instruments
to be looked at again to see that no mistake has been made.
The maximum and minimum thermometers to be set ; the former by
holding the bulb downwards, and gently shaking the instrument, and
the latter by holdiog the bulb upwards and allowing the index to flow
to the end of the spirit.
The thermometers to be read to tenths of degrees. The reading of the
maximum thermometer to be entered in the return to the previous day.
360
HINTS TO TRAVELLERS.
the readings of the other thermometers being entered to the day on which
they are read.
Cloud. — Tlie amount of clond to be estimated according to the scale
0-10, 0, representing a cloudless sky, and 10 a completely covered or
overcast sky.
The rainfall to be entered to i\\Q previoufi day.
When snow falls, that which is collected in the funnel to be melted V)y
adding a known quantity of warm water, and entering the difference as
rain. If the snow has drifted, a section of the snow should be obtained
in a place where it has not drifted, by inverting the funnel and turning
it round, and melting what is enclosed. It is also desirable to measure
with a rule the depth of snow in several places where it has not drifted,
and enter the amounts in the " Eemarks."
Weather. — Notes on the general character of the weather during the
day, and any phenomena such as fog, snow, thunder, &c., to be given in
the " Eemarks" column.
The following symbols to be used for brevity:
Eain
K Thunderstorm
:^< Snow T Thunder
A. Hail ^ Lightning
A Soft Hail = Fog
4» Snow Drift
— » Ice Crystals
^ Strong Wind
^-^ Eainbow
u
,^ Dew
1—1 Hoarfrost
V Silver Tliaw
~ Glazed Frost
O
Solar Halo
VL'
Lunar Halo
07
Lunar Corona
^
Aurora
Note. — The observations must be ioken punctiuilJy at 9 a.m. local time,
and with great care. As there must not be any break or omissions in the
observations, it is desirable that there should be a well-trained deputy to
take them in the absence of the regular observer.
METEOROLOGY AND CLIMATE.
361
Form.
Climatological Observations at 9 a.m. (Local Time) made at
cluring 18 . Heii^ht above Sea-level
feet
Thermometeus.
o
11
<
Date.
1
i
'5
Remarks.
1
2
&c.
o
o
o
O-IO
]n.
Sums
Maximum Temperature ('corrected') on
Minimum Temperature (corrected) on
Mean Temperature (Mean Max. and I\Iin.)
Means
Mean Range of Temperature
Index Errors
Means
Corrected.
No. of Rainy Days
'
362
HINTS TO TRAVELLERS.
Taijle of
Difference between the Readings of
0-2 0-4 ' 0-6 ' o'i
I-O I*2 ! 1-4 16
2*0 2-2 ' 2*4 ' 2-6 I 2*8
98
99
99
99
99
99
99
98
95
97
97
97
88 84
90
90
90
91
91
9J
9}
93
9J
94
94
81
78
«4
82
«7
8,-
89
«7
89
«7
89
89
90
90
90
91
90
92
91
92
91
92
9'
92
91
92
91
9J
92
9}
92
89
89
67
64
7?
-I
7«
7<>
80
79
81
3o
82
81
84 I ij
84 &}
METEOROLOGY AND CLIMATE.
363
Relative Humidity.
THE Dry and Wet Bulb Thermometers.
o
i;
1:1
3-2
1:1
3-6
3-8
4-0
4-2
4'4
4-6
4-8
5-0
5-2
5-4
5-6
5-8_
n
29
27
25
2?
21
19
18
17
16
15
14
13
12
n
20
•■
36
33
31
29
27
25
23
21
19
18
17
15
»4
13
1 2
22
39
36
34
32
30
29
27
25
23
21
19
18
17
16
15
24
43
41
39
37
35
3?
31
29
27
26
25
23
21
20
'9
26
50
48
40
44
42
40
58
36
M
?3
32
30
29
27
26
28
58 55
S3
51 49
47
45
44
42
40
39
37
36
35
,.
!o
65 6}
6f
60 58
51
54
53
;i
5a
48
47
45
44
42
32
•/I 1^9
67
65
63
62
60
59
57
56
55
53
52
51
50
34
74 72
';i
69
68
6ft
64
'ij
61
60
59
58
r
55
54
;6
76
74
7J
71
7°
69
67
66
64
63
62
61
60
58
57
38
76
7;
74
7^
71
70
68
67
65
'4
63
62
61
60
59
4'J
77
76
75
73
72
70
69
68
t6
65
64
63
62
61
60
42
78
77
76
74
73
72
71
70
68
67
65
64
63
62
61
44
78
77
76
74
73
72
7>
70
68
67
66
65
64
63
62
4ft
79
78
77
75
74
73
72
71
69
68
67
66
65
64
63
4«
79
78
77
75
74
73
72
71
70
69
68
66
65
64
63
50
80
79
78
7&
75
74
73
72
71
70
69
67
66
65
64
52
80
79
78
77
76
75
73
72
71
70
69
68
67
&•)
65
54
81
80
79
77
76
75
74
73
72
71
70
69
68
67
66
56
82
81
80
78
77
76
75
74
73
72
71
70
69
68
67
58
82
81
80
78
77
76
75
74
73
72
71
70
69
68
67
60
82
81
80
79
78
77
76
75
74
73
72
71
70
69
68
62
82
81
80
79
78
77
76
75
74
73
72
71
70
69
68
^A
8j
82
81
80
79
78
77
76
75
74
73
72
71
70
69
66
8J
82
81
80
79
78
77
76
75
74
73
72
71
70
69
68
8j
82
81
80
79
78
77
76
7;
74
74
73
72
7«
70
70
83
82
81
80
79
79
78
77
76
75
74
73
72
71
70
72
84
83
82
81
80
79
78
77
76
75
74
73
72
71
70
?^
84
83
82
81
80
80
79
78
77
76
75
74
73
72
71
85
84
83
82
81
80
79
78
77
76
75
74
73
72
71
78
85 84
8 J
82
81
80
79
78
77
76
76
75
74
73
72
80
864
HINTS TO TRAVELLERS.
Tai!LE of Relative
Difference between the Readings ok
c«
6-0 6-2
6-4|6-6 6-8
T2 , 7-4 t6 7-8
3-0 8-2 8-4 I 8-6 8-8
69
58
60
61
62 61
29 I 28
3^ 36
45 ; 44
49 48
56 54 5J
57 5& I 55
57 , 5&
58 57
59 i 58
59 58
60 59
61 1 60
65 64
65 I 64
66 65
70 ■ 69
6?
65
66
65
M
66
67
66
67
67
68
»,
59
59
60
59
60
59
61
60
62
61
62
61
62
61
61
62
64
6?
64
6?
65
64
5
5
5 ;
7.
7
6 ;
10
9
9 1
15
•4
'4 ;
2?
22
21
?o
29
29
n
}(>
J6
42
41
40
45
44
4?
47
46
45
49
48
'^l
50
49
48
51
50
49 '
52
51
50
5?
52
5t
54
5}
5^ i
55
54
5J 1
56
55
54
57
56
55
58
57
56
58
57
56
59
58
57
60
59
58
60
59
58
61
60
59
61
60
to
62
61
61
65
62
61
6?
62
6l
64
6!
62
5 4
6
8 8
METEOROLOGY AND CLIMATE.
365
HujiiDiTY. — Continued.
THE Dey and Wet Bulb Thebmometers.
9-0 9-2 9-4!9-6 9-8
5 5 5 5
7 1 \ ^ ^ 6
10 lo
i8 17
27 26
4,i 42
44 4J
46 I 45
47 I 46
48 i 47
49 I 48
50 ! 49 48
51 ; 50 I 49
52 ' 51
5J I 52 i 51
15 15
24 I 2J
H io
J? M
J8 il
40 39
41 40
4J 42
44 45
4i 44
47 46 45
47 46
48 47
50 49 48
50 49
54 5J 52 51 50
55 '54 5J 52 5'
55
55
54
5?
52
56
55
54
5f
52
56
5t'
55
54
5J
57
57
5")
55
54
58
57
S6
55
54
59
58
57
56
"
59
59 1
58
57
5b
60 59 58 57
60 60 I 59 58
lo-o I 10-2 10-4 ' IO-6
28
n
34
40
4'
42
[i'2 II '4 ii'6 II
4J
42
i ■♦'
4'
44
44
4?
4J
45
4-'
44
44
46
40
45
45
47
47
46
46
48
47
46
46
49
48
47
47
50
49
48
48
51
50
49
49
52
51
5?
50
52
51
50
50
SJ
52
51
51 1
54
5?
52
52
54
5J
52
52
55
54
51
5J
55 1
54
51
5J
40
42
4J
44
45
?} 52
54 55
5') 55
57 56
58 57
40
4'
42
4!
45
49 ' 48
44
44
45
45
46
46
47
47
47
47
49
50
50
51
52
52
a»i
366
HINTS TO TRAVFJ.T.ERS.
Tahle of Eklative
Difference
BETWEEN
THE
Eeadings
OF
j
I2-0 I2'2
12-412 6
12-8
ij-o
15 2
13-4
ir6
13-8
14-0
14-2
14-4
14-6
14-8
20
22
. . 1 . .
'4
26
28
'
; i ^
4
JO
10
10
9 9
9
8
8
7
7
-
6
6
6
6
5
J2
16
16
15 15
i;
14
14
13
iJ
15
12
12
II
II
II
i4
2J
2}
22 21
21
20
20
19
18
18
'7
>7
16
16
15
Jfi
27
27
26
25
25
^i
It
23
23
23
22
22
21
21
20
J8
29
29
28
27
27
26
25
25
24
24
23
23
22
22
40
JI
J I
50
29
29
28
28
27
27
26
25
25
25
24
24
4^-
?2
}I
51
}o
30
29
29
28
28
27
26
26
26
25
25
44
J4
33
5J
52
32
31
51
}o
30
29
28
28
27
^ 26
26
4'^
Ji
J4
54
55
35
32
32
}i
31
30
29
29
23
27
27
4«
J6
55
55
54 J4
33
33
32
32
31
30
30
29
29
29
50
52
38
J9
57
58
36
58
35
37
35
31
34
36
It
33
35
33
35
32
34
32
35
51
32
31
32
30
31
50
31
54
40
J9
39
38
38
37
37
36
36
35
34
33
33
32
32
56
4'
40
40
39 J9
38
37
36
36
35
35
54
34
33
33
58
4?
42
4«
40 40
39
39
38
38
37
36
55
35
34
34
•
60
45
42
42
41
41
40
59
J8
38
37
57
J6
36
35
i5
62
44
45
4f
42
42
41
40
39
39
38
38
37
r,
36
J6
64
4?
44
44
45
45
42
41
40
40
39
59
58
33
37
37
66
46
45
45
44
44
43
42
41
41
40
40
39
39
33
38
68
46
45
45
44
44
43
42
41
41
40
40
59
39
38
38
70
47
46
46
45
•^f
44
43
42
42
41
41
40
40
39
59
■;2
48
47
47
46
•♦^
45
44
43
45
42
42
41
41
40
40
■f
48
47
47
V'
46
'^l
45
44
44
45
45
42
42
41
41
76
49
48
48
47
47
46
46
"»!
'^1
44
45
45
45
42
42
73
50
49
49
48
48
47
47
46
'*2
45
44
45
45
42
42
80
50
49
49
48
48
47
47
46
46
45
45
44
44
43
45
METEOROLOGY AND CLIMATE.
367
Humidity. — Continued.
THE Dry and
Wet Bulb Thermometers.
£ si
,
I
°
00
i 1
£«
.S-o
15-2 15-4 156
15-8
i6-o i6-2 i'j-4 i6-6 i6-8
17-0
172
'"•4
I7-6
12:^_
i8-o
.......
••
20
22
24
5
5
5
5
4
4
}0
10
10
10
10
9
9
9
8
8
8
7
7
7
7
6
6
n
15
»5
14
14
14
13
13
13 12
12
12
II
II
II
10
10
34
2o
19
19
18
18
17 17
16 16
15
15
14
14
14
ij
13
3&
21
21
20
20
20
19 19
18 18
>7
17
16
16
16
•5
15
33
2;
2J
22
22
22
21 21
20 20
19
19
18
i8
18
17
i"
40
J4
24
23
23
23
22 22
21 21
20
20
19
19
19
18
18
42
2 5
25
?4
24
24
23 23
22 21
21
21
20
20
20
19
'9
20
44
:0
26
2;
25
2i
24 24 2! 2;
22
21
21
21
21
20
4'3
28
2~
27
26
26
25
24
2 3 23
22
22
22
21
21
20
20
43
:9
28
28
27
27
26
26
25
25
24
24
23
22
22
21
21
jc
JO
29
29
28
28
27
27
26
26
25
25
24
24
24
23
23
52
jr
?o
30
29
29
28
28
27
27
26
26
25
25
25
24
24
25
27
54
3i
32
32
31
3t
30
29
29
28
28
27
27
26
26
25
iO
J4
JJ
33
32
32
31
31
30
30
29
29
28
28
28
27
5 a
!5
J4
34
3t
3?
32
32
31
31
JO
30
.29
29
28
28
27
28
60
J5
j;
34
34
33
35
J!
32
32
?i
31
30
30
29
29
62
36
J6
35
35
34
34
13
32
32
31
31
30
30
29
29
29
JO
"A
?7
36
36
35
35
J4
34
33
33
32
32
32
31
31
30
J8
J7
37
36
36
35
35
34
34
i}
33
33
32
32
31
31
68
J8
38 37
37
36
36
35
35
35
34
34
33
J3
32
32
? J
70
59
39 J 8
!8
i7
37
36
36
35
35
34
34
34
33
JJ
32
33
34
34
35
72
40
40 39
39
38
38
37
37
36
36
35
35
35
34
!4
74
41
40 4-5
39
39
38
38
37
37
37
36
36
36
J 5
35
76
4'
41 40
40
39
39
39 38
38
37
37
36
36
iS
35
78
42
41 41
40
40
39
39 38
38
37
37
30
36
35
35
80
368 HINTS TO TRAVELLERS.
In the Table is given the relative humidity for every 2° of temperature
from 20° to 80°, and for every two-tentlis of a degree of difference between
the dry and wet-bulb readings from 0''*2 to 18° "0.
To use the Table : Ijook in the column on the left or right for the
nearest degree to the dry-bulb reading ; then carry the eye horizontally
along until the column is reached corresponding to the difference between
the readings of the dry and wet-bulb thermometers, when the relative
humidity will be found. Intermediate readings can be interpolated in
the usual way.
Example: Dry-bulb 58° -5, wet-bulb 52° -7, the difference is 5° -8.
Having found 58° in the column on the left or right, run the eye along
this line until the column under 5° '8 is reached when the relative
humidity will be found, viz., 67.
Hints to Meteorological Observers in Tropical Africa, with
Instructions for taking Observations.
Prepared hy a Committee of the British Association for the Adoanccment of
Science, I89I. E. G. Eavenstein, f.r.g.s., Chairman ; Baldwin
Latham, c.e., f.g.s. ; G. J. Symons, f.r s. ; H. E. Mill, d.sc ,
Secretary.
The Committee appointed by the British Association are prepared to
supply a few competent and approved observers in Tropical .\frica with
the following instruments : —
1. A Fortin's Barometer.
2. A Dry Bulb Thermometer.
3. A Wet Bulb
4. A Maximum ,,
5. A Minimum „
0. A Eain Gauge.
The Thermometers are placed within a cage of galvanised iron, ready
for suspension under shelter.
The corrections to be applied to the readings of the instruments
furnished by the Committee have been ascertained, and will be forwarded
to each observer. Observations, however, shoiild be entered in the
METEOEOLOGY AND CLIMATE. 360
Begister as actually recorded by the instrument, and without applying
any of these corrections.
Observers making use of instriiments not supplied by the Committee,
are earnestly requested to furnish a description of them (maker's name
and number), with such notes on their errors as may be in their possession.
Every opportunity for comparing the instruments at a station with
other instruments in the possession of travellers and others should be
availed of.
The Committee will be happy to make careful ahstracfs of any Meteoro-
logical Journals from Africa which may he intrusted to them.
They will also forward (gratis) copies of these ' Hints,' and of their
' Eegister,' to any observer who may apply for them.
Descriptions of certain instruments, not as a rule supplied by the
Committee, will be found in 'Hints to Meteorological Observers,' pre-
pared under the direction of the Council of Eoyal Meteorological Society
by W. Marriott. London (Stanford), 1892. Price Is. These instruments
are the Kew barometer, Philips's maximum thermometer, black and
bright bulb thermometers in vacuo, grass minimum thermometer,
Symons's earth thermometer, percolation gauge, Eobinson's anemometer,
and the sunshine recorder.
Notes on Mounting the Instruments.
Fortin's Barometer should be mounted in a room not subject to sudden
or great changes of temperature. Care should be taken to suspend the
instrument vertically, to place it in a good light and not near a fire-
place, or where it is exposed to the sun.
It is to be fixed at such a height that the observer can read the vernier
comfortably when standing upright. 'J'lie height of the cistern above the
ground should be noted in the register.
Barometers should be carefully handled. Before moving one first turn
the screw below the cistern until the mercury fills the tube, then turn
the barometer carefully over, and carry it with the cistern end upwards.
Thermometers. — The thermometers are placed within an iron cage, wliich
should at all times be kept locked, so as to prevent interference with the
instruments. This cage is suspended under a thatched shelter, which should
be situated in an open spot at some distance from buildings, must be well
2 (;
370
HINTS TO TKAVELLERS.
ventilated, and guard the instruments from being exposed to sunshine or
rain, or to radiation from the giound. A simple hut, made of materials
available on the spot, would answer this purpose. Such a hut is shown in
the accompanying drawing. A galiled roof with broad eaves, the ridge of
whicli runs from north to south, is tixed upon four posts, standing four
feet apart. Two additional posts may be introduced to support the ends
of the ridge beam. The roof, at each end, projects al)Out 18 inches. In
-i — 9—ifee(
^ 1
c
1 1
Ground Plan
Circular Hut
¥
Front V;en' "
Side Vie w
it are two ventilating holes. The tops of the posts are connected by bars
or rails, and on a cross-bar is suspended the cage with the instruments.
These will then be at a height of six feet above the ground. The gable
ends may be permanently covered in with mats or louvre work, not
interfering with the free circulation of the air, or the hut may be
circular.
The roof may be covered with palm-fronds, grass, or any other material
METEOEOLOGY AND CLIMATE. 371
locally used by the natives as building material. The floor should not be
bare, but covered with grass or low shrubs.
Care should be taken to fix the cage firmly, so that the maximum and
minimum thermometer may not be disturbed by vibration.
Bain Gauge. — It should be firmly fixed in the ground with the top of
tlie rim one foot, or if on bare soil one foot three inches, above it, and
perfectly horizontal.
Wind Vane. — The vane should be placed where it is freely exposed to
tlie action of the wind, and not interfered with by local conditions. It
should be higher than the trees or buildings near it, and under any
circumstances about 25 feet above the ground. Its north point is readily
obtained by means of a compass, applying, as a matter of course, the local
variation.
Instructions for Taking the Observations.
Hours of Observation . — At stations of the second order the instruments
are to be read at 7 a.m., 2 p.m., and 9 p.m., with the exception of the
maximum and minimum thermometers and the rain gauge, which are
only read at 7 a.m.
At climatological stations the observations are made only once daily,
viz., at 9 a.m.
Register. — All the original observations should be written down at the
time in a properly ruled r.ote-book, which should be preserved for
reference in case any question should arise about them afterwards.
In entering the observations in the register supplied by the Committee
it is absolutely essential that they be correctly copied from the original
note-book, and carefully checked.
The first Monthly Register should be accompanied by a description of
the station and of its environs, as also an account of the situation, &c., of
the instruments. Any subsequent changes in the latter should be duly
noted.
Fortiris Barometer. — 1. Note (to nearest degree) the reading of attached
thermometer.
2. Bring surface of mercury in the cistern into contact with the
ivory point which forms the extremity of the scale by turning the screw
at the bottom of the cistern. The ivory point and its reflected image in
2 c 2
372
HINTS TO TRAVELLERS.
the mercury should api)ear just to toucli each other and form a double
cone.
3. Adjust the vernier scale so that its two lower edges shall form a
tangent to the cojii-ea; surface of the mercury. The front and back edges
of the vernier, the top of the mercury, and the eye of the observer are then
in the same straight line.
4. Take the reading, and enter the ohservntion as read without either
correcting it to freeziug-iioint or reducing it to the sea-level.
The scale fixed to the barometer is divided into inches, tenths, and
half-tenths, so that each division on this scale is eqiial to 0050 inch.
The small movable scale or vernier attached to the instrument enables
the observer to take more accurate readings ; it is tnoved by a rack and
pinion.
Twenty-four spaces on the fixed scale corresi3ond to twenty-five
spaces on the vernier ; hence each space on the fixed scale is larger than
a space on the vernier by the twenty-fifth part of 0"050 inch, which is 0"002.
Every long line on the vernier (marked 1, 2, 3, 4, and 5) thus corresponds
-to G-dlO inch.
METEOROLOGY AND CLIMATE. 373
If the lower edge of the vernier coincides with a line on the fixed scale,
and the upper edge with the twenty-fourth division of the latter higher
up, the reading is at once supplied by the fixed scale as in Fig. 1, where
it is 29"500 inches.
If this coincidence does not take place, then read off the division on
the fixed scale, above which the lower edge of the vernier stands. In
Fig. 2 this is 29'750 inches. Next look along the vernier until one of its
lines is found to coincide with a line on the fixed scale. In Fig. 2 this
will be found to be the case with the second line above the figure " 2."
The reading of the barometer is therefore : —
On fixed scale 29-750
On vernier (12 X -002) .. .. -024
Correct reading 29-774
Should two lines on the vernier be in equally near agreement with two
on the fixed scale, then the intermediate value should be adopted.
5. Lower the merciiry in the cistern by ti:rning the screw at tlie bottom
until the surface is well below the ivory point; this is done to prevent the
collection of impurities.
Dry Bulb and Wet Bulb Thermometers. — Eeadings should be entered
without ap])lying any corrections for the errors of the instruments. They
should be stated in degrees and tenths of degrees.
Five, or preferably ten, minutes before reading the Dry Bulb Thermo-
meter in damp weather it is to be wiped dry.
The Wet Bulb Thermometer requires special attention. The bulb
should be covered with a piece of the thinnest muslin. Eight threads of
darning cotton, in the form of a noose, should be loosely tied round the
neck of the bulb, and led through a small hole in the cover of the water
receptacle or cui?. Take. care to have this cup at all times filled with
clean rain or filtered water. •
The nmsiin and the conducting threads should be washed in boiling
water prior to use, and changed at least once a month, or whenever there
is any apj^earance of dirt upon them.
When the temperature sinks below freezing-point, wet the bulb with a
camel hair brush about an hour before use; this will produce a thin
coating of ice.
374 HINTS TO TRAVELLERS.
After a frost the water in the receptacle should be thawed, and the
muslin and conductor washed, to restore ]n-oper action.
Maximum Thermometer (Ncgretti & Zambra's). — 1. See that the end of
the column nearest the bulb has not run away from it through vibration
or otherwise. If it has the thermometer should be tilted very gently
until the detached column comes in contact with the contraction in
the tube.
2. Eead at 7 a.m. or 9 a.m. by noting the point at which the end of the
column of mercury is lying. Enter to jirevious day.
3. Set, by holding tlie thermometer bulb downwards, and shaking it
until the mercurial column becomes continuous throughout. The end of
the mercury should then indicate the same temperature as the Dry Bulb
Thermometer.
Minimum Thermometer (Eutherford's). — 1. Eead at 7 a.m. or 9 a.m. by
noting position of the end of the indiQX furthest from the bulb. Enter to
the day on which read.
2. Set, by raising the bulb and allowing the index to slide to the end of
the column of spirit. When set, the end of the index furthest from the
bulb should indicate nearly the same temperature as the dry bulb.
Ruin Gauge. — The gauge should be examined daily at 7 a.m. or at 9 a.m.
During exceptionally heavy rains it may be necessary to measure the
contents of the gauge at more frequent intervals, but the total results
should in all cases be inserted in the register under the hours named.
The rain measured at 7 a.m. or 9 a.m. should be entered as having
fallen the previous day.
The measurement is effected by pouring the contents of the gauge
(bottle or can) into a glass measure, each division of which represents
()"01 in. The reading to be taken midway between the two apparent
surfaces of the water.
If hail or snow should be collected in the funnel, it is to be melted and
measured as rain. This is done by adding to the hail or snow a measm-ed
quantity of hot water, and by afterwards deducting the quantity so added
from the total measurement.
Wind. — Note the direction from wliich the wind blows from the
indications of a freely-moving vane, or by observing the drift of
smoke by means of a magnetic compass, applying the correction for
variation.
METEOKOLOGY AND CLIMATE.
375
The Force of the Wind is to be noted according to Beaufort's scale, as
follows : —
0. Calm .
1. Light Air
2. Light Breeze
3. Gentle „
4. Moderate,,
5. Fresh „
6. Strong „
7. Moderate Gale
8. Fresh
9. Strong „
10. Whole
11. Stonn .
12. Hurricane
Corresponding Velocity in
Miles per Hour.
. 0— 6
. 6—10
. 11—15
. 16—20
. 21—25
. 26—30
. 31—36
. 37—44
. 45—52
. 53—60
. 6i— 69
. 70—80
. 81 and ui:)wards.
Clouds. — HhQ pro} ortion oftliesky covered with cloud is to be estimated,
the scale adopted being 0—10, representing a perfectly cloudless sky,
and 10 showing that the tvhole sky is clouded.
The forms of cloiids should be described as defined by Howard, as
follows : —
Cirrus : — Parallel, wavey, or diverging fibres.
Cirro-cumulus : — A fleecy cloud. ■
Cirro-stratus: — A thin veil of feathery or streaky cloud.
Cumulus : — A cloud of a convex or well-rounded shape.
Cumulo-Stratus : — A blending of Cirro-Stratus with Cumulus.
Stratus : — Clouds in continuous horizontal sheets.
Nimbus or rain cloud.
Under motion enter the direction whence the cloud is moving.
Weather. — Note any phenomena which may have occm-red since the
last observation.
Term-Baijs.— On the 1st, lltli, and 21st of each month hourly or
two-hourly observations should, if possible, be taken, those of the 21st
being the most important. This applies more especially to the barometer
and its attached thei-mometer, and to the dry and wet bulb thermometers.
376 HINTS TO TRAVELLERS.
Additional Observations. — If the station is favonraTily situated for
measuring the height of a lake-level or ascertaining the flooding of a
river, this should be done. Tliese observations should be made regularly
daily, but if tliis is imjjracticable, once a week is much better than none.
The water-gauge should' be divided into inches and tenths. The manner
of fixing it must depend entirely upon local circumstances: its zero
should coincide with the lowest level of the water, but in practice it will
generally be necessary to accept au arbitrary zero, and to indicate all
readings bi'low it by a minus sign. It is desirable that the zero of the
gauge sliould be referred to a bench mark cut in the face of a rock, or
failing that, in the trunk of a tree.
Well-measurements may prove of interest. Measure the distance from
the moiitli of the well to the surface of the water in it, and not the deptii
of the well. At stations on the sea-shore, on lakes or rivers, the tempera-
ture of the water may likewise be recorded.
Note hij Egbert H. Scott, f.r.s.
• Eoctract from the Eeport of the International Meteorological Conference
held at Munich, Septemher, 1891.
1. It should be stated what kind of instruments had been used for the
observations, their corrections should be given, if known; as well as
details as to the method of exposure. The height of tlie barometer above
sea-level should be given as accurately as possible.
2. Precise information as to the methods employed in the calculation
of means (the hours of observation and the formulie used for reductions)
should always be given.
It is further desirable to give the means for the separate hours of
observation (for temperature, humidity, and atmospheric pressure), to
facilitate the reduction to true means, which might be undertaken
subsequently.
3. In iniblishing means for several years, it is very desirable to give
the separate means for periods of five years each (lastra) (commencing
with the first year of each pentade : — 1881-5, 1886-90, &c.), in accordance
with the resolution of the Congress of Vienna. In this way it would bo
LIST OF METEOEOLOGICAL STATIONS 377
Ijossible to obtain with the greatest facility simultaneous and corresponding
mean "values which are indispensable for any serious investigations on
the distribution of meteorological elements, especially temperature, atmo-
spheric pressure, and rainfall.
List of Meteorological Stations and Organisations, 1893;
Furnished by the Meteorological Office.
Asia.
Asia Minor.
Beirut E. H. West, Esq., M.A., Supeiiutendent, Lee Obser-
vatory, Syriau Protestant Colle2;e.
Cyprus The Chief Medical Officer, Larnaka.
China.
Zi-ka-wei Rev. F. S. Chevalier, S.J., Observatoire Mague'tique et
Me'teorologique, Zi-ka-wei, pres Shanghai.
HoDg-Kong .. .. Dr. W. Doberck, Government Astronomer, Observatory.
Japan.
Tokyo M. Kobayashi, Director, Imperial Meteorological Ob-
servatory, Tokyo.
India.
Calcutta .J. Eliot, Esq., M.A., Meteorological Reporter to the
Government of India.
Africa.
West Africa.
Lagos The Colonial Surgeon, Colonial Hospital.
Algeria.
Algiers M. le Directeur du Service Me'teorologique.
South Africa.
Cape Town . . . . W. E. Fry, Esq., Secretary, Meteorological Commission.
WalfischBay .. .. Dr. Stapff.
East Africa.
Mauritius C. Meldrum, Esq., LL.D , F.R.S., Secretary, Meteoro-
logical Society.
378 HINTS TO TRAVELLERS.
North Africa.
Cairo Administration des Services Sanitaires et d'Hygiene
Publique.
Madagascar.
Mojanga S. C. Knott, Vice-Consul.
Antananarivo . . . . Royal Observatory, M. Colin, S.J.
America.
North America.
Washington .. .. Weather Bureau.
Labrador (Six stations.) German Missionaries.
Canada.
Toronto C. Carpmael, Esq., M.A., jMetcorological Office.
South America.
Cordoba Sr. W. G. Davis, Oficina Meteorologica Argentina.
Porto Alogre .. .. Dr. G. Alves d'Azambuja, Porto Alegre, South Brazil.
Georgetown .. .. G. S. Jenman, Esq., Government Botanist's Office,
Georgetown, Demerara.
Rio de Janeiro . . . . Capt. Adolph Pinheiro, Bureau Hydrographique.
Central America, &c.
Havana Padre B. Vines, S.J., Director, R. Colegio de Belen,
Havana, Cuba.
Mexico The Director, Observatorio Central del Palacio
Nacional.
Tacubaya Sr. Angel Anguiano, Observatorio AstronomicoXacioual.
Tobago J. P. Tulloch, Esq., M.D., Colonial Surgeon.
Trinidad J. H. Hart, Esq., Superintendent, Botanic Gardens.
Belize St. Joseph's College.
Costa Rica . . . . Meteorological Institute.
Australasia.
New South Wales.
Sydney H. C. Russell, Esq., F.R.S., Observatory.
Queensland.
Brisbane C. L. Wragge, Esq., F.R.A.S , Government Meteoro-
logist.
South Australia.
Adelaide Sir C. Todd, K.C.M.G., F.R.S., Superintendent of
Telegraphs.
LIST OF METEOROLOGICAL STATIONS. 379
Tasmania.
Hobart Hon. Secretary, Royal Society of Tasmania.
Victoria.
Melbourne .. .. R. J. Ellery, Esq., F.R.S., Observatory.
West Australia.
Perth M. A. 0. Eraser, Esq., Meteorological Reporter.
New Zealand.
Wellington . . . . Sir J. Hector, C.M.G., M.D., F.R.S., Colonial Museum.
Java.
Batavia Dr. J. P. van der Stok, Director, Observatory.
Philippine Islands.
Manila The Director, Meteorological Observatory.
Sandwich Islands . . H. Cubb- Adams, Kaneohe (Oahu).
Fiji J. D. W. Vaughan, Suva.
Samoa Dr. Frank, Apia.
This list, of course, is very far from exhaustive. The Russian Government
has established a great number of stations throughout the Empire. The number
of places where observations are regularly taken is yearly increasing, and the
traveller will do well to inquire where such stations exist in the neighbourhood
of his explorations. — Euitoes.
( 380 )
vn.
GEOLOGY.
By W. T. Blanford, f.b.s.
A TRAVELLER wlio lias iiot devotecl some time to studying geology in the
tield must not be surprised or disappointed if the rocks of any country
which he may happen to traverse appear to him a hoj^eless puzzle. If he
desires to investigate the geological structure of an unknown region, he
should previously devote some time to mastering, with the aid of a good
geological map and description, the details of a well-known tract.
Under the term " Geological Observations," two very distinct types
of inquiry are commonly confounded. The first of these, to which
the name of Geological Investigation ought properly to be restricted,
consists in an examination of the rocks of a country as a whole, so as
to enable a geological map, or, at all events, geological sections, to be
constructed. This demands a knowledge of rocks (petrology), some
acquaintance with the details of geological surveying, and, usually, with
the elements of palceontology — a science that, in its turn, requires a
preliminary study of biology, and especially of zoology. Despite all these
hard terms, any intending traveller who has a taste for geology — if he
has none he had better not waste time upon the subject — will find that a
few months' study in any good museum, a course of geological lectures,
and, above all, a few days in the field with a good geologist, will start
him very fairly equipped with the great requisite to all successful
scientific investigation, a knowledge of how to observe, and what to observe.
The term " Geological Observations "is, however, often, but incorrectly,
used in a second sense, which implies a restriction of the observations to
the useful minerals found in any country, or to what is termed economic
geology. Here also a preliminary knowledge of the elements of geological
science will be found very useful, and will frequently enable the traveller
GEOLOGY. 381
to form much more trustworthy conclusions as to the nature and vahre of
mineral deposits than he could without such a guide. But the essential
point is to recognise a valuable mineral when seen, and for this some
knowledge of mineralogy is requisite.
Outfit. — The essential articles of a geologist's outfit are neither numerous
nor cumbrous. A very large proportion of the known geology of the
world has been made out with no more elaborate appliances than a
hammer, a pocket compass, with a small index to serve as a clinometer, a
]')Ocket lens, a note-book and a pencil. No scientific observer has to
depend more on his own knowledge and faculty for observation, and less
on instrumental appliances, than a geologist.
The best hammer for general irariTOses should weigli from 1 to 2 lbs.
and should have a square flat end, and a straight cutting end— the latter
may be horizontal or vertical, according to fancy. The ends should be of
steel, not too highly tempered. The hole for the handle should be as large
as possible (with a small hole the handles are so weak as to be liable to
break), and the handle should be secured in the hole by a wooden wedge,
and an iron one driven into and across the wooden one. It is advisable
to take a few spare ash handles. Cut a foot-measure in notches on the
handle — this is very useful for measuring thickness of beds, &c. It is as
well to have more than one hammer in case of loss, and if fossil-collecting
is anticipated, at least one heavy hammer, with one end fashioned to serve
as a pick, three or four cold chisels of various sizes, and a short crow-bar
will be found usefi;l. Excellent geological hammers are those used by
the Irish Geological Survey, and made by Kennan, of Dublin. In London,
haiumers, chisels, &c., may be procured of J. E. Gregory, 88, Charlotte
Street, Fitzroy Square ; or of Messrs. Buck, 242, Tottenham Court Eoad.
A very good pocket compass, the shape and size of a watch, with a
clinometer arm, is made by Troughton and Simms, 138, Fleet Street.
The use of the clinometer is for measuring the angle of dip in rocks.
The elaborate instruments used for mininft,' purposes are imnecessary to
the geologist. If more accuracy of measurement is required than is
afforded by looking at a bed, a section, or a hill-side, and hokliug the
straight-edge attached to the compass parallel to the di]i. and if a siirface
can be found that affords the exact inclination, it is usiially practicable,
by means of a note-book laid on the rock surface, to obtain a plane suffi-
ciently close to that at which the beds di}) to enable the angle to be
382 HINTS TO TRAVELLERS.
detei'uiined with a very sliort straight-edge. As a rule, except with very
low angles of dip, the variation in the inclination of the rocks themselves
exceeds the limits of error of the instrument. A little care, however, is
necessary in taking dips ; for the apparent dip seen in a section, such as
is often exposed in a cliff, may differ widely from the true dip, which will
only be shown if the section runs at right angles to the strike of the
beds. Dips seen on the sides of hills at a distance are but rarely correct
for the same reason.
A prismatic compass and an aneroid are frequently of great service :
the former to determine the position on the map, if one exists, and to
aid in making a rough map, if there is none ; and the latter to estimate
roughly the heights on the road travelled, especially in mountainous
countries, and also to measure the thickness of horizontal beds. Both
form a part of the oixtfit of most modern travellers. A good aneroid
gives sufficiently accurate determinations of height for a rough but
adequate geological section across any country, if the distances are
known.
Collections. — Geological specimens require little more than i^aper and
boxes for packing. Occasionally fossils or minerals are fragile, and need
tow or grass to protect them from injury ; but there is no risk from the
animal and vegetable enemies of zoological or botanical collections. The
only important point to be borne in mind is that every specimen should he
lahelled on the spot, or, at all events, in the course of the day on which it
is collected. Strong paper is best for labels, and these should not be put
up in contact with the rock-fragments themselves, or they will be worn
by sharp edges and become illegible, if not rubbed to fragments. Always
wrap each specimen in liajDer, or some substitute, then add the label, and
then au outer covering. The label,* if nothing else is written, should
always record the locality distinctly written.
* Travellers in tropical countries will do wisely to poison all their labels before
using them, to preserve them from attacks of insects and mites. "Washing with
a very weak solution of corrosive sublimate is an efficient plan. A large number
of labels, with the collector's name printed on them, may be taken, and if made
of strong thin paper they will not occupy much space. Bank-note paper is well
adapted for the purpose. Any writing should be, if possible, in ink : if not, a
very hard black pencil should be used.
GEOLOGY. 383
A collection of rock specimens may show what kinds of rock occur in a
country, but the information afforded is very meagre, and, in general, of
very small value. Such collections, indeed, unless made by a geologist,
and accompanied by notes, are scarcely worth the carriage. If such
specimens are taken, care should be used to select them from the rocks
in place, not from loose blocks that may have been transported from a
distance, and no fragments of spar or crystals should be collected merely
because they are pretty.
In taking specimens of useful minerals, such as coal or metallic ores,
the traveller should always endeavour to jirocure them himself from
the place of occurrence, and if such are brought to him by natives, he
should, if practicable, visit the locality whence the samples were pro-
cured. The value of all useful minerals depends both on quality and
quantity ; the former can to some extent be ascertained from a sample,
but the amount available can only be estimated after a visit to the locality.
Most metallic ores occur in veins or lodes. These were originally cracks
in the rock, and have been irregularly filled with minerals, different from
those in the neighbourhood. It is, however, very difficult, and often
impossible, to estimate from surface examination whether the quantity
of ore occurring in veins is likely to prove large ; some idea may possibly
be obtained if underground workings exist. Many of the ores of iron,
some of those of other metals, and all coal and salt occur in beds, and
here it is important to see what is the thickness, and to ascertain whether
the mineral is equally pure throughout. Iron ores occur in most
countries, and unless very pure and within easy reach of water-carriage,
are not likely to be worth transport. The value of salt also depends on
facilities for carriage. Coal, however, may be of value anywhere ; but it
is improbable that seams of less thickness than four or five feet can be
of much use, except in countries where there is a skilled mining popula-
tion and a considerable demand for the mineral. It does not follow
because much thinner seams are sufiiciently valuable to be worked in
Western Europe that they would pay for extraction in a country where
the mechanical arts are less advanced. Still the occurrence of thm seams
is worthy of record, as thicker deposits may exist in the neighbourhood.
It must not be inferred, however, that a seam of small thickness at the
surface will become thicker below. The reverse is equally probable.
A blow-pipe is extremely useful for ascertaining the nature of ores, and
384 HINTS TO TRAVELLERS.
for determining minerals generally, and a small blow-pipe case might
be added to a traveller's kit, if ho thinks it probable that he may-
meet with minerals in any quantity. But in general tliey are not to be
found in such in-ofusion as to render it difficult to carry away specimens
sufficient for determination at leisure. A blow-pipe, too, is of no use to
any one unacquainted with the method of employing it, though this is
easy to acquire.*
To form a rough idea of the valne of iron ore, see whetiier it is heavy;
to form some notion of the quality of coal, pile up a heap and set fire to
it. If it does not burn freely, the prospects of the coal being useful are
small. It may be antliracitic, and very valuable with proper appliances;
but anthracite is not of the same general utihty as bituminous coal.
Good coal should burn freely, with more or less flame, and should leave
but little ash, and it is preferable that the ash should be white, not red,
as the latter colour is often due to the presence of pyrites, a deleterious
ingredient.
Gold and gems have, as is well known, been procured in consider-
able quantities from the sands of rivers and alluvial deposits. The
deposits known to the natives of any country are often of small value,
and the rude methods of washing prevalent in so many lands suffice
to afford a fair idea of the wealth or poverty of the sand washed.
Gold and, wherever it is found, platinum occur in grains and nuggets,
easily recognised by their colour and by their being malleable ; but gems,
such as diamond, ruby, sapphire, are not so easy to tell from less valu-
able minerals. They may be recognised by their crystalline form and
hardness. A diamond is usually found in some modification of an octo-
hedron, and the crystalline facets are often curved ; rubies and sap-
phires are really differently coloured varieties of the same mineral, and
occux', when crystalline, in six-sided pyramids or some modification. A
diamond is the hardest of known substances ; nothing will scratch it, and
it will scratch all other minerals. Sapphire will scratch everything
except diamond.
* There are plenty of good works on the use of the blow-pipe. The best are
by Plattner and Scheerer, of both of which English translations have been pub-
lished. Of Vou Kobell's tables for the dLterminatioii of ujinerals, several trans-
lations have appeared,
GEOLOGY. 385
In collecting fossils, it is useless to take many specimens of one kind
unless carriage is exceptionally plentiful. Two or three good examples of
each kind are usually suflScient, but as many kinds as possible should be
collected. Great care is necessary that all the specimens from one bed
be kept distinct from those from another stratum, even if the bed be
thin and the fossils in the two beds chiefly the same species. If there
is a series of beds, one above the other, all containing fossils, measure
the thickness roughly, draw a sketch-section in your note-book, apply
letters or numbers to each bed in succession on the sketch, and label the
fossils from that bed with the same letter or number.
Eemains of Vertebrata, especially of mammals, birds and reptiles, are of
great interest ; but it is useless to collect fragments of bones without
terminations. Skulls are much more important than other bones, and
even single teeth are well worth collecting. After skulls, vertebrae
are the most useful parts of the skeleton, then the limb bones. If com-
plete skeletons are found, they are usually well worth some trouble in
transporting. If fossil bones are found abundantly in any locality, and
the traveller has no sufficient means of transport, he will do well to carry
away a few skulls, or even teeth, and carefully note the locality for the
benefit of future geologists and explorers. The soil of limestone caverns,
and especially the more or less consolidated loam, rubble, clay, or sand
beneath the flooring of stalagmite, if it can be examined, should always
be searched for bones, and also for indications of man or his works.
The foregoing remarks are intended for all travellers, especially for
those who have paid little or uo attention to geology. It would be far
beyond the object of the present notes to attempt to give instruction in
the methods of geological observation ; all who wish to know more fully
what questions are especially worthy of attention, should consult tlie
article on Geology by the late Dr. Charles Darwin and Professor J. Phillips
in the ' Admiralty Manual of Scientific Enquiry.' But a few hints may be
usefully added here for those who have already some knowledge of geology,
who do not require to have such terms as dip, strike, fault, or denuda-
tion explained to them, and who are sufficiently conversant with geo-
logical phenomena to be able to distinguish sedimentary from volcanic,
and metamorphic from unaltered rocks, and to recognise granite, gneiss,
schist, basalt, trachyte, slate, limestone, sandstone, shale, &c., in the field.
Assuming then that a traveller with some knowledge of field geology is
•2 r>
386 HINTS TO TRAVELLERS.
making a Jourucy tliroiigli a tract of the earth's surface, the geology of
which is nnknowii, what will be the best method of procedure and the
principal points to which he should direct his attention?
On tlic whole, the most useful record of a journey, whether intended
for publication or merely as a memorandum, is a sketch geological map of
the route followed, with the dips and strikes of the rocks and approxi-
mate boundaries to the formations, supplemented by notes and sketch-
sections. Where, as is commonly the case in mountain-chains, and fre-
quently in less elevated portions of the country, the rocks are much
disturbed, and esi^ecially if the number of systems exposed is large and
the clianges frequent, no traveller can exj^ect to do more than gain a very
rough and general idea of the succession of beds in detail, and of the
structure; but by making excursions in various directions, whenever a
halt is practicable, by searching for fossils as a guide to the age and for
the identification of beds with each other, and by carefully noting the
general dij) and strike of the more conspicuous beds, it is often jjossible,
especially if an opportunity occurs of retracing the road followed, or of
traversing a iDarallel route, to make out the structure of a country that
at first appears hopelessly intricate. Dense forest is perhaps the worst
obstacle to geological exploration ; snow is another, though not quite so
serious a disadvantage. It is always a good plan to climb commanding
peaks ; the general direction of beds, obscure from the lower ground, not
unfrequently becomes much clearer when they are seen from above.
In level and undulating regions, on the other hand, it frequently
happens that enormous tracts of country are oceuiiied by the same
formation, and if the rocks are soft, and especially if they are horizontal,
or nearly so, little, if any, rock is to be seen in place. In this case
water-courses should be searched for sections, and the i^ebbles found in
the stream-beds examined, care being taken not to mistake transported
pebbles derived from overlying alluvium or drift for fragments of the
underlying rock. Where the same formation i>revails over large tracts,
it is usually easy, by examining the stones brought down by a stream, to
learn whether any other beds occur. It is astonishing how even a small
outcrop of hard rock at a remote spot in the area drained by a stream
will almost always yield a few fragments that can be detected by walking
two or three hundred yards up the stream-bed and carefully examining
the pebbles.
GEOLOGY. 387
Kot unfreqiieutly different rocks support different vegetal ion, and by
noting the forms that are pecuhar, the constitution of hills at a consider-
able distance may be recognised. Thus some kinds of rock will be found
to support evergreen, others deciduous trees, others grass, whilst a fourth
kind may be distinguished by the poverty or want of vegetation. It is
not well to trust too much to such indications, but they may show which
hills require examination and which do not. The form assumed by the
outcrop of some hard beds is often characteristic, and may be recognised
at a considerable distance.
One most important fact should never be forgotten ; mineral character,
whether of sedimentary or volcanic rocks, is absolutely worthless as a
guide to the age of beds occurring in distant countries. The traveller
should never be led to suppose, because a formation, whether sedimentary
or volcanic, in a remote part of the world, is mineralogically and struc-
turally identical with another in Europe, or some country of which the
geology is well known, that the two are of contemporaneous origin. The
blunders that have been made from want of knowledge of this imiDortant
caution are innumerable.
There are a few points of geological interest well worthy of the investi-
gation of those who traverse unexplored, or partially explored, tracts of
the earth's surface. Amongst these are the following : —
Mountain- Chains. — -Few, if any, geologists now believe that mountains
were simply thrust up from below ; all admit that, at least in the majority
of cases, where great crumbling of the strata has taken place, there has
been lateral movement of the earth's crust. Bat the causes, extent and
date, of the lateral movements are still, to a great extent, matters of
conjecture, and every additional series of observations bearing on the
question is of importance. There are many mountain-chains of which
very little is yet known. In each case good sections are required, draAvn
as nearly to scale as jiracticable, through the range from side to .«ide, and
including the rocks on the flanks. The nature and distribution of all
volcanic and crystalline rocks, both in the range and throughout the
neighbouring areas, are especially noteworthy, and also the relations of
the later beds, if any, on the flanks of the mountains, to those constituting
the range itself, the derivation of the materials of the former from tlie
latter, and the relative amount of disturbance shown by the two, and by
the different members of each.
388 HINTS TO TRAVELLERS.
Volcanoes and I'olcanic Bocks. — It is almost needless to say that any
additional information on the distribution of volcanic vents, recent or
extinct, is of interest. In the case of extinct vents, the geological date
of the last eruptions should be ascertained if practicable. This may
sometimes be determined by finding organic remains or sedimentary beds
of known age interstratified with the ashes or lava-streams near the base
of the volcano.
Additional observations are needed as to the extent and age of those
enormous masses of stratified volcanic rocks that occur in some parts of
the earth, as in the western i)art of the Indian Peninsula, Xorth-eastern
Africa, the Western States of North America, and on a smaller scale in
parts of Europe.
Coasts. — The subject of the erosion of coasts is now fairly understood,
and there is no doubt that the importance of this form of denudation was
greatly overrated by many geological writers, who took their ideas of
geological denudation generally from the phenomena observed in the
islands, and on some of the coasts of Western Europe. Still, wherever
cliflfs occur, they afford good sections, and deserve examination. One
question w^ill usually present itself to almost every geological observer,
and that is, whether any coast he may be landing upon aifords evidence
of elevation or dein'ession. In the former case, beds of rolled pebbles or
of marine shells, similar to those now living on the shore, may be found
at some elevation above high-water mark. Very often the commonest
molluscs in raised beds are the kinds occurring in estuaries, which are
different from those inhabiting an open coast. Caution is necessary, how-
ever, that heaps of shells made by man, or isolated specimens transported
by animals (birds or hermit-crabs), or by the wind, be not mistaken for
evidence of raised beds. If the shore is steeji, terraces on the hill-sides
may mark the levels at which the sea remained in past times, but some
care is necessary not to mistake outcrops of hard beds for terraces. If
dead shells of species of mollusca, only living in salt-water estuaries, are
found in places now beyond the influence of the tide, it is a reasonable
inference that elevation has taken place.
The evidence of depression, on the other hand, unless there are buildings
or trees partly sunk in the water, is much less readily obtained, and
neither trees nor buildings are available as evidence, unless the depres-
sion is of comparatively recent date. The best proof is the fonn of the
GEOLOGY. 389
coast. If deep inlets of moderate breadth occur, with rmmerous branches,
a little examination will frequently show whether such inlets are valleys of
snbaerial erosion, as they not ucfrequently are, that have been depressed
below the sea, A good and familiar example of such a depressed valley
is to be found at Milford Haven in South Wales. In higher latitudes,
care must be taken not to mistake glacier valleys, such as the friths and
lochs of Scotland, and the fiords of Norway, for valleys of subaiirial erosion
that have recently undergone subsidence. It is highly probable, even in
this case, that the valleys were originally formed by fresh-water denuda-
tion, and that they have been depressed, but their features have been
modified by the action of ice.
Rivers mid Rioer-Pluins. — At the present time a question of much
interest is the antiquity of existing land-areas, and some light may be
thrown upon this, if the relations of existing river-basins to those of past
times can be determined. If a stream cuts its way through a high range,
it is probable that the stream is of greater antiquity than the range, and
either once ran at an elevation higher than the crest of the ridge now
traversed, or else has cut its way through the range gradually during the
slow elevation of the latter. Where a river traverses a great alluvial
plain, it may fairly be inferred that a long time has been occupied in the
accumulation of the deposits to form the plain; but it remains to be seen
whether those deposits are not partly marine or lacustrine. If upheaval
has taken place over any portion of the plain, or if the river has cut its
bed deeper, sections may be exposed, and these should always be ex-
amined for fossil remains. Bones of extinct animals are not unfreqiiently
found in such deposits.
Lakes. — The mode of origin of lakes is always a subject of considerable
geological interest. Some lakes occupy areas of depression; others
valleys of erosion, the drainage from which has been stopped by local
elevation, by land-slips, or by deposits from tributaries, whilst very
many, and amongst them some of great size and depth, occur in
regions that have been covered by ice; and it is still a moot point
how far these lakes are due to partial changes in the elevation
of the country, some observers having adopted, while others dispute
the views of the late Sir A. Eamsay, who believed all these hollows to
have been scooped out by ice moving over the surface in the form of
a glacier or of an ice-sheet. Of the smaller lakes, some are dammed
390 HINTS TO TRAVELLERS.
up by landslips, some by glacial moraines, and a few occupy volcanic
craters.
Evidence of Qlacial Action, — Closely connected with the subject of
lakes is that of glacial evidence generally. There is pro\)ably no geo-
logical 'qi;cstion which has produced more si^eculation of late years than
the inquiry into the traces of a comi:)aratively recent cold period in the
eartli's his-tory. Chisely connected with this inquiry is the equally im-
portant question as to the former occurrence of similar glacial epochs at
regular or irregular intervals of geological time.
The evidence of the last glacial epoch may be traced in two ways —
by the form of the surface, which has been modified by the action of
ice, and by changes that have taken place in tlie fauna and flora of the
coimtry in consequence of the alteration in the climate. The effects of an
ice-sheet, like that now occurring in Greenland, if such formerly existed
in comparatively low latitudes, miast have been to round off, score and
polish the rocks of the country in a peculiar manner, easily recog-
nised by those familiar with glaciated areas.* Glaciers, properly so
called, are confined to hilly or mountainous countries, and the valleys
formerly occupied by them retain more or less the form of the letter U
instead of taking the shape of the letter V, as they do when they have
been cut out by running water. The sides of the valley, when modified
by a glacier, have a tendency to assume the form of slopes unbroken
by ravines, and with all ridges planed away or rounded, whilst in ordinary
valleys of erosion by water, the sides consist of a series of side valleys or
ravines, divided from each other by sharp ridges running down to the
main valley. Large and small masses of rock, preserving to a considerable
exteut an angular form, but frequently polished and grooved by being
ground against the sides or bottom of the valley, are carried down by the
ice, and either left behind, perched ujihigh on the slopes of the valley, or
accumulated in a vast heap or bank, known as a terminal moraine, at the
spot where the ice has terminated. The nature of the rock will usually
show whether the fragments on the side of a hill or at the bottom of a
valley are derived from the higher parts of the drainage area, or whether
* Care should be taken that the peculiar scoring and grooving of rock surfaces
produced by the action of sand transported by the wind be not mistaken for
glacial evidence.
GEOLOGY. 391
they have merely fallen down from the neighbouring slopes. In the latter
ease, they may be due to landslips ; in the former, their shape and the
erosion they have undergone will aid in showing whether they have been
transported by water or ice.
The surfaces that have been modified by earlier glacial epochs must
in general have been long since removed by other denuding agencies.
The most important evidence of former ice action consists in the
occurrence, embedded in fine sediment, of large boulders, occasionally
preserving marks of polish and striation, and usually, though not always,
angular.
It is well to scarcli in all mountain ranges for traces of glacial
action. In many mountain chains, even in comparatively low latitudes,
proofs have been found of the existence of glaciers, at a much lower level
than at present, dating from a comparatively recent geological period,
whilst in other mountain regions none have been recognised. The qiies-
tion also whether glacial action has been contemporaneous in the two
hemispheres is of the greatest importance, and the evidence hitherto
adduced is of a very conflicting character.
Deserts. — The great sandy or salt plains, with a more or less barren
surface, that occupy a large area in the interior of several continents, have
only of late years received due attention from geologists. A great thick-
ness of dejjosits must occur in many of thesj vast, nearly level, tracts, for
the underlying rocks are often completely concealed over immense areas.
The investigation of the deposits is frequently a matter of great difficulty
for want of sections ; but, where practicable, a careful examination should
1)0 made, and exact descriptions of the furmations exposed recorded.
Some, at all events, of these beds appear to be entirely deposited from the
air, and consist of the decomposed surfaces of rocks and the sand and
silt from stream deposits, carried iip by wind and then redeposited on the
surface of the country. Such deposits are very fine, formed of well-
rounded grains, and, as a rule, destitute of stratification. The geologist
who has especially described these formations. Baron F. von Eichthofen,
in his work on China, attributes to the loess of the Rhine and Danube
valleys a similar origin. It is usual to find beds due to water-action,
rain- wash and steam-deposits, interstratified with the subacrial accumu-
lations. Further observations on these formations are desirab'e. The
occurrence of blown sands, the origin of these accumulations, and the
392 HINTS TO TRAVELLERS.
peculiar ridges they assume, usually at right angles, but in some remark-
able cases parallel to the prevailing winds, are questions deserving of
additional elucidation.
Early TKsitory of Man in Tropical Climates. — Very little has been dis-
covered as to the races of men formerly inhabiting tropical regions. It is
evident that a race unacquainted with fire could only have existed in a
country where suitable food was procurable throughout the year, and
this mu.st have been in a region possessing a climate like that found in
parts of the tropics at the present day. It is possible that an investi-
gation of the cave deposits in the troi^ics may throw some light on this
subject. " Kitchen middens," as they are termed — the mounds that have
once been the refuse heaps of human habitations — arc also worthy of
careful examination.
Permanence of Ocean-Basins. — Witliin the last few years some geologists
have adopted the theory that all the deep-sea area has been the same
from the earliest geological times, and that the distinction between the
depressions occupied by the oceans and the remaining undepressed portion
of the earth's crust, constituting the continents and the shallow seas around
their coasts, is permanent. This view is very far from being universally
or even generally accepted amongst geologists, although many who
hesitate to accept the theory as a whole admit that parts of the oceans
have in all probability been deep basins since the earth's crust was first
consolidated.
The argument on both sides depends upon theories to which travellers
can contribute but little except by observations on the geology, fauna,
and flora of oceanic islands, and by the investigation of coral-reefs and
especially of atolls. In ranges of hills or moiintains near the coasts both
of 'continents and islands and in all tracts where evidence of recent
elevation exists, search should be made for deep-sea deposits. These are
fine calcareous or argillaceous beds, often containing small Foraminifera
or Radiolaria, which, however, are generally extremely minute, and
require microscopical examination for detection. If any beds of con-
solidated calcareous ooze or especially if red or grey clay be found
associated with pelagic deposits, such as coral limestone, a few small
fragments of such beds should always be brought away for examination,
and any distinct fossil remains found in sunk beds, such as echinoderms
(sea-urchins or star-fishes) or sharks' teeth, should be carefiilly preserved
GEOLOGY. 393
with some of tlie matrix. Deep-sea dei^osits have recently been discovered
in several parts of the world, for instance, the West Indies, the Solomon
Islands, and the islands of Torres Straits.
Atolls or Coral-Islands. — The remarkable coral islands of the Pacific and
Indian oceans consist usually of an irregular ring, part or the whole of
which is a few feet above the sea, and which encircles an inner lagoon of
no great depth in general. The outer margin of the reef aroimd each
island slopes rapidly, sometimes precipitately, to a depth of, usually,
several hundred fathoms. Darwin, taking these facts into consideration,
together with the circumstance that no coral reefs are known to be
formed at a greater depth than about 15 to 20 fathoms, showed that all the
facts of the case conld be explained by the theory that coral-islands were
formed in areas of subsidence. This view was generally accepted until
lately, when Mr. Miirray and other writers liave brought forward evidence
in favour of coral-islands being founded on shoals that may be areas
of elevation.
The only crucial test of depression would be a series of borings through
the coral limestone of a typical atoll to a depth of 300 or 400 feet.
Prof. J. D. Dana has shown that coral rock has been found at a
depth of more than 800 feet in borings near Honolulu in the Sandwich
Islands; but the case is not typical, and tlie cores from the borings did
not receive a sufficiently thorough examination to prove their origin as
reef- coral. Fresh observations on the limits of depth to which reof-
forming corals are confined would be valuable. Meantime any additional
details would be useful, such as careful soundings around atolls, so as to
give an accurate profile of the sea-bottom in the neighbourhood.
394 TITNTS TO TRAVELLERS.
MEMORANDUM ON GLACIER OBSERVATIONS.
hxned hy tJic Committee of the Alpine Chih.
The recent movements of glaciers may be noted by the following
signs : —
When the ice is advanciu?;, the glaciers generally have a more convex
outline, the icefalls are more broken into towers and spires, ayd piles of
fresh rubbish arc found shot over the grass of the lower moraines.
Moraines which have been comparatively recently deposited by advancing
ice are disturbed, show cracks, and are obviously being pushed forward
or aside by the glacier.
When the ice is in retreat, the marks of its further recent extension are
seen fringing the glacier both at the end and sides in their lower portions,
the glacier fails to fill its former bed, and bare stony tracts, often inter-
spersed with pools or lakelets, lie between the end of the glacier and the
mounds of recent terminal moraines.
Where a glacier has retreated to any considerable extent, careful ob-
servations of the form of its bed are of value. What is the natiire of the
rock surfaces exposed — convex or concave; are they rubbed smooth on
their leesides ; how far have the contours of the cliffs or slopes, or the
sides of any gorge, been modified where they have been subjected to ice-
friction? Is there any evidence that the ice has flowed over large
boulders, or loose soils, such as gravel, without disturbing them ? How
has it affected rocks of different hardness, for instance, veins of quartz in
a less hard rock ? Generally, do the appearances indicate that the glacier
has excavated, or only abraded and polished its bed ; that it has scooped
out new rock-basins, or only cleaned out, scratched, and preserved from
filling-up by alluvial deposits or earthslips, existing basins ? What is the
general character of the valley bottom and slopes above and below the
mo.st conspicuous ancient moraines ?
The depth of mountain lakes and the position of the point of greatest
depth should be ascertained wherever possible. The marginal rock
structure of lake basins, particularly near their outlet, is of some im-
portance with a view to ascertaining whether they are true rock basins,
MEMORANDUM ON GLACIEE OBSERVATIONS. 395
or whether they are reservoirs formed by ancient moraines, earthslips, or
alluvial deposits.
The traveller or surveyor should, if possible, paint a mark and date on
any conspicuous rock in situ parallel with the termination of the glacier
at the time of his visit, marking the distance in yards of the ice from it.
The next visitor -will then be able to measure the movement that has
taken ])lace since his predecessor's visit. Leaving out of question elabo-
rate trigonometrical methods, such, for instance, as have been carried
out on the Ehone Glacier in Switzerland, the following plan gives very
valuable results, and demands no other instruments than a small jar of
paint, a brush, a measuring tape, and a pocket compass. To ascertain
the recent retreat of a glacier, measure the distance from the end of the
ice in front of the longitudinal axis of the glacier to the most advanced
terminal moraine, where vegetation first shows itself. The bare ground
recently left by glaciers is easily recognisable. The diminution of volume
is best measured by ascertaining the height of bare soil left on the sides
of the lateral moraines in the portion of the glacier within the zone of
vegetation. All photogi-aphic representations of the glacier end, and of
the ground which has been freed from the glacier ice, are of great value.
Those will be of most service that show the position of the glacier-snout
with relation to some conspicuous rock or other feature in the local
scenery. Each photograph should' be dated, and the bearings and
distance of the camera with reference to any such feature accurately
noted.
It is very important to investigate the state of various glaciers as regards
advance or retreat. Neighbouring glaciers often furnish very different
results in this respect, owing to the fact that steep glaciers anticipate in
their oscillations those the beds of which are less inclined. To ascertain the
oscillations of glaciers, it is necessary to fix the actual position of the ice-
snout at the end of the glacier with the greatest accuracy. Two methods
can be employed for this purpose, either of which may be selected accord-
ing to circumstances.
Paint some signs on large bouUlers, not too far from the end of the
glacier, and measure their distance from it by a taps (Richter's system),
or build a low wall of stones of a few yards in length, and, .say 15 to 20
inches in height, some distance from the ice-end, and measure this distance
(Gossefs .system). It is to be recommended that the stones of these walls
396 HINTS TO TRAVELLERS.
should also be painted. If the traveller himself returns after some interval
— even after only two or three weeks — he will be able to judge of the
movement of the glacier, and he will have laid down a basis for further
observations by future travellers.
One of the results most to be desired is an exact knowledge of the
dates :
I. Of the maximum extension of the ice.
II. Of the commencement of retreat,
III. Of the minimum.
IV. Of the commencement of fresh increase.
In dealing with a mountain group, therefore, the traveller should note
(where he can get the information as to the past) the date of the commence-
ment of the actual movement of each glacier, and in all cases whether the
ice is ill advance, or retreat, or stationary. Of course the rate of forward
movement, or velocity of the ice, and the oscillations in the extension of
the ice must be kept carefully distinct.
Should time and circumstances permit, a series of observations of the
velocity of the ice is of value. These may be made after Tyndall's method,
by planting a line of sticks across the glacier, or by painting marks
on boulders, the position of which relatively to ascertained points on the
mountain-side has been accurately fixed. The size of the glacier, that is,
the area of its basin and its length, as well as the slope of its bed above,
as well as at the point measured, should be noted. The rate of movement
of the ice appears to be connected both with the volume of the glacier
and the inclination of its bed.
( 397 )
VIII.
NATUEAL HISTORY.
By H. W. Bates, f.e.s.
Revised by P. L. Scla.tek, f.k.s.
In the present state of biological science, travellers wlio intend to devote
themselves specially to the zoological or botanical investigation of new
or little-known countries, require to be trained for the work beforehand,
and will be necessarily well-informed as to methods and appliances. It
is not for them that these ' Hints ' are drawn iip, but for general travellers
and explorers, who, whilst engaged chiefly in survey, wish to know how
best to profit by their opportunities of benefiting science by collecting
exami^les of new or rare species, and how to preserve and safely
transmit their specimens. The observations refer only to explorations by
land.
Outfit* — A double-barrel gxm ; for large aquatic birds, &c., a breech-
loader to be preferred, and wire cartridges. For Central Africa, and
regions where large mammals are found, a more powerful weapon is
also required. Mr. Thomson took with him on his Masai Land expedition
a breech-loading 8-gauge elephant gun, double- barrel, smooth bore, and
weighing about 11 lbs., and fitted with a thick Silver's patent anti-recoil
heel-plate ; with its leather cover, powder measure, bullet-fixer and
mould, &c.
If percussion-cap guns are used, fine powder in canisters, and fine shot,
must be taken from England ; coarse powder and shot can be had at any
* Implements, &c., for collecting and preserving birds, insects, &c., can be
obtained of Mr. Janson, 44, Great Kussell Street, W.C, or Messrs. Watkins
and Doncaster, 36, Strand, W.C. ; for the larger animals, as well as other articles
of general travelling outfit, of Messrs. Silver and Co., 67, Cornhill, and Old
Bond Street, W.
398 TirNTS TO TRAVELLERP.
trading settlement. A good snpjily of the best caps and a few spare
nipples should be taken, as also the following articles : —
Arsenical soap in tin boxes; brushes of different sizes for applying
the same ; a small supply of carbolic acid, and a few insect " killing
bottles:"* Bottle of rangoou oil. Scalpels, scissors (including a pair
of short-bladed ones), needles and thread. Long straight forceps
(similar in form to curling irons), very useful for inserting cotton
into the necks of bird-skins, to avoid stretching them ; of two or three
sizes. Bone nippers and screw-driver.
A few small traps, with which to caj^ture small (mostly nocturnal) mam-
mals. The " Excelsior " and "Premier" traps, always set and baited,
are recommended, as they capture small mammals without injuring
them. For spring traps the " American wire-trap " is to l)e preferred, as
they are very light and of different sizes, and a large number weigh little
and occupy small space.
Stone jars for reptiles and fishes in spirit ; to fit four in a box, with
wooden partitions. If animals in spirit are to be collected largely, the
tin collecting-case described further on, and a supply of sheet-tin or zinc,
with a pair of soldering-irons and a sufficient quantity of soft solder, must
be taken instead of, or in addition to, stone jars. Cylindrical cases can
then be made of any size required. By means of the soldering apparatus
also empty powder-canisters, and other tin vessels, can be easily converted
into receptacles for specimens.
A short landing-net for water-molluscs and other small aquatic animals.
A stout hoop-net (the stick 4 or 5 feet long crossing the hoop) for cap-
turing insects on the wing and for sweeping herbage for Coleoptera, &c. ;
a few yards of silk gauze for nets in reserve.
* These bottles are for collecting all kinds of hard-bodied insects on an
excursion, and should be of a size to fit the pocket, strong, and with broad
mouths. The insecticide paste adhering to the bottom can be easily made by the
traveller. A pellet of cyanide of potassium (the size of a pea) must be dissolved
in water in the bottle, and suflioieut powdered pla&ter of Paris mixed with it
until the water is absorbed, when the whole sliould be pressed down into a hard cake
an inch iu thickness. A simpler plan is, a pellet of cyanide wrapped in paper
placed in the bottle half full of coarse-grained sawdust ; at a pinch, a small
quantity of spirits in the bottle will do; but the insects must on no account oe
left more than a day or two in the spirit.
NATURAL HISTORY. 399
A supply of triaugular i^aper envelopes for Lepidoptera, &c. Boxes
of light wood of various sizes (about the size of cigar-boxes) for
storing and packing specimens. Tin boxes may be used in very damp
climates, provided the contents are well dried before storing; and the
general outfit of an expedition may be much lightened by having all the
provisions, and otlier consumable articles, packed in tin cases, and in
boxes and jars of such forms as may render them available for containing
specimens.
As a preservative against the attacks of insect vermin, a su^jply of
" Papier Preservateur " will be found most useful. Each box should be
wrapped in a sheet of this paper.
In humid tropical countries, where the ubiquitous ants are likely tO'
destroy specimens before they are ready to be jmcked away, drying-cages,
suspended from the roof of a hut or tent, are absolutely necessary. These
can be readily made from old packing-cases, but a few square feet of wire
gauze must be provided for the back and front of the cages, and the cord
by which they are suspended must be threaded through a small calabash
containing oil, to prevent ants from descending from the roof. The
cages may be so arranged as be taken to pieces and put together again
readily ; one, for birds, should be about 2 feet 6 inches long by 1 foot
6 inches high and 1 foot broad ; the other, for insects and other small
specimens, may be about one-third less. They should have folding doors
in front, with panels of wire giiuze, and the backs wholly of the latter
material; the sides fitted with racks to hold six or eight plain shelves,,
which in the smaller cage should be covered with cork, or any soft wood
that may be obtained in tropical countries. A strong ring fixed in the
top of the cage, with a cord having a hook attached at the end by which
to hang it in an airy place, will keep the contained specimens out of
harm's way until they are quite dry, when they may be stowed away in
their close-fitting boxes.
A few yards of india-rubber waterjiroof sheeting, as temporary coveriu"-
to collections in wet weather, or in crossing rivers.
A set of carpenter's tools for making boxes and packing-cases.
Where and lohat to collect. — The countries w^hich are now the least
known with regard to their natural history, are New Guinea and the
large islands to the east of it, Northern Australia, the interior of Borneo,
Tibet, Indo-Ohina, and other parts of Central Asia, Equatorial Africa,-
400 HINTS TO TRAVELLERS.
and tlie eastern slopes of tlie Andes, from Bogota to Bolivia. A
special interest attaches to the indigenous productions of oceanic
islands, i.e. islands separated by a deep sea from any large tract
of land. Those who have opportunities could not fail to make in-
teresting discoveries by collecting specimens of the smaller animals
(insects, moUuscs, &c.) and plants in these isolated localities. Both in
continental countries and on islands the truly indigenous species ■will
have to be sought for on hills and in the remote parts, where they are more
likely to have escaped extermination by settlers and the domestic animals
introduced by them. In most of the better-known countries the botany
has been better investigated than tlie zoology, and in all there still remains
much to be done in ascertaining the exact station, and the range, both
vertical and horizontal, of known species of animals and plants. This
leads us to one point, which cannot be too strongly insisted on, namely,
that some effective means should be adopted by the traveller to record the
exact locality and date of every specimen he collects. AVith regard to the
larger dried animals this may be done by written tickets attached to
the sjjecimens ; if insects are pinned, a ticket may be fixed on the pins ;
and if packed unpinned in boxes, all taken in one place should be laid to-
gether, and a common label placed with them. When all the
specimens taken at one place can be put into a separate box, one memo-
randum upon the box itself will be sufficient. Keptiles and fishes should
have small parchment tickets attached to them before they are placed in
spirits, and the writing on them should be in pencil, not in ink. In
mountainous countries, the approximate height above the sea should be
noted,
A traveller may be puzzled, in the midst of the profusion of animal
and vegetable forms which he sees around him, to know what to secure
and what to leave. Books can be of little service to him on a journey,
and he had better at once abandon all idea of encumbering himself with
them. A few days' study at the principal museums before he starts on
his voyage may teach him a great deal, and the cultivation of a habit of
close observation and minute comparison of the specimens he obtains will
teach him a great deal more. As a general rule, all specimens which he
may meet with for the first time far in the interior should be preferred to
those common near the civilised jjarts, and he should bear in mind that
the few handsome kinds which attract the attention of the natives and are
NATURAL HISTORY. 401
offered for sale to strangers are almost sure to be of species well known i)i
European museums. He should strive to obtain as much variety as pos-
sible, and not fill his boxes and jars with quantities of specimens of one
or a few s])ecies. But as some of the rarest and most interesting species
have great resemblance to others which may be more common, he should
avail himself of every opportunity of comparing the objects side by
side. In most countries, as already remarked, the truly indigenous, and
often the rarest, species are to be found only in the mountains at con-
siderable elevations and in the primitive forests, the products of cultivated
districts being nearly all widely distributed and well known. In botany
a traveller, if obliged to restrict his collecting, might confine himself to
those plants which are remarkable for their economical ixses; always
taking care to identify the flowers of the tree or shrub whose root, bark,
leaves, wood, &c., are used by the natives, and preserving a few specimens
of them. But if he has the good fortune to ascend any high mountain
not previously explored, he should make as complete a collection of the
flowering plants as possible, at the higher elevations. The same may be
said of insects found on mountains, where they occur in great diversity —
on the shady and cold sides rather than on the sunny slopes— under
stones, and about the roots of herbage, esi^ecially near springs, on shrubs
and low trees, and so forth; for upon a knowledge of the plants and
insects of mountain ranges depend many curious questions regarding the
geographical distribution of forms over the earth. In reptiles, the smaller
Batrachians (frogs, salamanders, &c.) should not be neglected, especially
the extremely numerous family of tree-frogs; lizards may be caught gene-
rally with the insect sweeping-net ; the arboreal, or rock haunting species
seen out of reach, and the swift-running forms that inhabit sandy plains
may be brought down with a charge of dust-shot. Snakes should be taken
without injuring the head, which is the most important part of the body :
a cleft stick may be used in securing them by the neck, or they may be
shot, and on reaching camp they may be dropped into the jars of spirits.
As large a collection as possible should be made of the smaller fishes and
tortoises of lakes and rivers.
Mainmah and Birds. — An ordinary geographical expedition will hardly
have the means at its disposal for bringing home many specimens of the
larger animals. But many species in regions visited only by adventurous
explorers are still desiderata in the large museums of Europe; and
2 E
402 HINTS TO THAVELL?]R8.
additional specimens of all genera of which tliere are numerous closely-
allied species {e.(j. rodents, antelope, deer, &c.), and of all the small
nocturnal mammals would be welcome to zoologists. If only portions
can be obtained, skulls with horns attached are to be preferred. In humid
tropica-l regions entire skins cannot be dried in time to prevent decay,
and it is necessary to place them rolled up in a small compass, in spirits.
The smaller birds shot on an excursion should be carried to camp in the
game-bag, folded in paper, the wounds, mouth and anus being first
plugged with cotton. Powdered calcined gypsum will here be found
very useful in absorbing blood from feathers, on account of the facility
with which it can be afterwards cleared from the specimens. Dull-
coloured and small birds are most likely to be new or interesting.
Immediately after killing a small mammal or bird, make a note of the
colour of its eyes and soft parts, and, if time admits, of the dimen.sions of
its trunk and limbs. It facilitates skinning of birds to break, before com-
mencing, the first bone of the wings a short distance above the joint, which
causes the members to lie open when the specimen is laid on its back on
the skinning-board. The animal should be laid with its tail towards the
right hand of the operator, and the incision made from the breast-bone
nearly to the anus. A blunt wooden style is useful in commencing the
operation of separating the skin from the flesh. When the leg is reached,
cut through the knee-joint and then clear the flesh from the shank as far
as can be done, afterwards washing the bone slightly with arsenical soap,
winding a thin strip of cotton round it, and returning it to the skin.
Repeat the process with the other leg, and then sever, with the broad-
bladed scissors, the s\)me above the root of the tail. By carefully cutting
into the flesh from above, the spine is finally severed without injuring the
slcin of the back, and it is then easy to continue the skinning up to the
wings, when the bones are cut through at the place where they had pre-
viously been broken, and the body finished as far as the commencement
of the skull. A small jiiece of the skull is now cut away, together with
the neck and body, and the brains and eyes scooped out, the inside washed
with the soap, and clean cotton filled in, the eyes especially being made
plump. lu large-headed parrots, woodpeckers, and some other birds, the
head cannot thus be cleaned ; au incision has, therefore, to be made either
on one side or ou the top of the head, through which the back of the skull
can be thrust a little away and then cleansed, the incision being after-
NATURAL HISTORY, 403
wards closed by two or three stitches. The bones then remaining in each
wing must be cleaned, which must be done without loosening the quill-
feathers. It is much better to take out the flesh by making an incision
on the outside of the skin along the flesh on the inner side of the wing.
The inside of the skin must now be washed with the soap, and a neck of
cotton (not too thick) inserted by means of the long narrow forcej^s,
taking care to fix the end well inside the skull, and withdrawing the
empty forcejDS without stretching the skin of the neck, and thus dis-
torting the shape of the bird. Skins need not be altogether filled up with
cotton or any other material, but laid, with the feathers smoothed down,
on the boards of the drying-cage until they are ready to be packed in
boxes. Each skin should be kept in a separate roll of brown pajDer, and
store boxes should be lined with brown paper, which is avoided by insects.
In very humid climates, like that of Tropical America, oxide of arsenic in
powder is preferable to arsenical soaj), on account of the skins drying
more quickly; but it cannot be recommended to the general traveller,
owing to the danger attending its use.*
In mammals the tail offers some difficulty to a beginner. To skin it, the
root (after being severed from the spine) should be secured by a piece of
strong twine, which should then be attached to a nail or beam ; with two
pieces of flat wood (one placed on each side of the naked root), held firmly
by the hand and pulled downwards, the skin is made rapidly to give way
generally to the tip. The tails of some animals, however, can be skinned
only by incisions made down the middle from the outside. The larger
mammal skins may be inverted, and, after washing with the soap, dried in
the sun; as before remarked, it is often necessary to roll them up and
preserve them in spirit.
The skins of small mammals and birds, after they are (luite dry, may be
packed in boxes, which must be previously well washed inside with
arsenical soap, lined with paper, and again covered with a coating of the
soap and well dried in the sun. This is the very best means of securing
the specimens from the attacks of noxious insects, which often, to the
* For further information about collecting bh-ds, formula for making arsenical
soap, &C., we may refer the traveller to Hume's ' Collector's Vade Mecum '
(Quaritcb, London. Price 2«.), and ' Directions for Collecting Biids,' issued by
the Smithsonian Institution, AVashingtoii, 1891-92.
2 E 2
404
HINTS TO TRAVELLERS.
great disgust of the traveller, destroy what he has taken much pains to
procure. Wlien -wood is scarce, as in the interior of Africa, l)Oxcs may be
made of the skins of antelopes or other large animals Tiy stretching them,
when newly stripped from the animal, over a square framework of sticks,
and sewing up the edges: after being dried in the sun they make excellent
packing-cases.
Preserving Mammah, &c., in AIcoJiol. — In the interests of science the
preservation, in alcohol, of mammals, as well as of reptiles, fishes and
Crustacea, is to be preferred, and the traveller is earnestly recommended
General Collecting-Case.
fo adopt this plan, especially with regard to the smaller specimens, dried
skins of which are almost useless for scientific purposes. On this subject
Dr. G. E. Dobson sends us the following ' Hints * :• —
The general collecting case should be made of strong block tin, rect-
angular in form, about 2 feet x 1 foot x 1 foot 8 inches in height, having in
the top a circixlar aperture from 6 to 8 inches in diameter, closed by a
well-fitting brass-screw cap, the flange of which is made air-tight by a
well-greased leather collar. This should fit accurately into a similarly
shaped box of inch boards, having a simple flat lid (not projecting beyond
the sides), secured by eight long screws, and provided with a strong iron
NATURAL HISTORY. 40o
handle. This case should be filled with the strongest methylated spirits
procurable (in foreign countries over-proof rum, brandy, or arrack will
suit equally well). If circumstances admit, two or more such cases
should be taken, or four wide-mouthed earthenware jars placed in a
square wooden case and seijarated by light wooden partitions, having
their mouths closed by well-fitting bungs tied down with bladder and
skin. On arrival at the collecting station one of the jars should be half
filled with spirit from the tin case. Into this each specimen, as it is
obtained, having a long slit made in the side of the abdomen, should be
put, and allowed to remain 24 hours before being transferred to the
general collecting case. When the latter can hold no more, the specimens
should be removed one by one and packed in the moist state in the other
wide-mouthed jars, one above the other, like herrings in a cask, each
rolled in a piece of thin cotton cloth, in which a label, having the locality
and date written in pencil, should be placed. When the jar has been thus
filled to the mouth a glass or two of the strong spirit (kept in reserve)
should be poured in so as to fill up interstices, but not to appear on the
surface, which should be covered with a thick layer of cotton-wool. A
few drops of carbolic acid, if the spirit be weak, will greatly aid its preserv-
ing powers. The bung should then be replaced, secured round the margin
outside with a mixture of tallow and wax, and tied down securely with
bladder or skin, and the name of the collector and district written legibly
'outside. The jar is now ready for transmission to any distance, for
specimens thus treated will keep good in the vapour alone of strong spirit
for months. Other jars may be filled in like manner, and, finally, the
general collecting case. Incisions should invariably be made in the sides
(not in the centre line) of all animals, so as to allow the spirit to enter,
and no part of the intestines should be removed. In the case of tortoises
the opening may be made in the soft parts round the thighs ; if this be
not done the body soon becomes distended with gases. Froris should
always be first placed in weak spirit, and after being soaked for one or two
days, be removed to strong alcohol. Crabs should be rolled up alive in
thin cotton-cloths, secured by thread tied round ; they are then readily
killed by immersion in alcohol; if this be not done they lose many
of their limbs in their dying struggles.
Preparation of iSkehions of Animals, — In many cases it will be found
impossible to preserve the whole animal, especially if of large size, but it
406 HINTS TO TRAVELLERS.
may advantageously be converted into a skeleton by attention to the
following directions of Sir W. H. Flower, f.r.s. : —
If the animal is of small size — say not larger than a fox — ^take off the
skin except from the feet below the wrist and ankle joints. If it is
intended to preserve the skin as a zoological specimen as well as the
skeleton, the bones of the feet should all be left in tlie skin ; they can be
easily extracted afterwards, and will be preserved much more safely in
their natural covering. Remove all the contents of the abdominal and
thoracic cavities ; also the larynx, gullet, and tongue. In doing this be
careful to leave attached to the base of the skull the chain of bones which
supports the root of the tongue. These may either be left in connection
with the skull, or cleaned separately and tied to the skeleton. Then
clear away, with the aid of a knife, as much as possible of the flesh from
the head, body, and limbs, without cutting or scraping the bones, or
separating them from each other. At any intervals that may be neces-
sary during this process it will be desirable, if practicable, to leave the
body in water, so as to wash away as much of the blood as possible from
the bones, and a few days' soaking in water frequently changed will be
an advantage.
The body, with all the bones held in connection by their ligaments,
should then be hung up to dry in a place where there is a free current of
air, and out of the way of attacks from animals of prey. Before they get
hard the limbs may be folded by the side of the body in the most con-
venient position, or they may be detached and placed inside the
trunk.
When thoroughly dry the skeletons may be packed in boxes with any
convenient light packing material between them. Each should be well
wrapped in a separate piece of paper or canvas, as sometimes insects will
attack the ligamentary structures and allow the bones to come apart.
If it can be avoided, skeletons should never be packed up so long as
any moisture remains in them, as otherwise decomposition will go on in
the still adhering soft parts, and cause an unpleasant smell.
If the animal is of larger size, it will be most convenient to take it
partially to pieces before or during the cleaning. The head may be
separated from the neck, the vertebral column divided into two or more
pieces, and the limbs detached from the trunk ; but in no case should
the small bones of the feet be separated from one another. The parts
NATURAL HISTORY. 407
should then be treated as above described, and all packed together iu a
canvas bag.
In the cetacea (porpoises, &c.), look for two small bones suspended in
the flesh, just below the vertebral column, at the junction of the lumbar
and caudal regions (marked externally by the anal aperture). They
are the only rudiments of the pelvis, and should always be preserved with
the skeleton.
If there is no opportunity of preserving and transporting entire
skeletons, the skulls alone may be Icept. They should be treated as
above described, picked nearly clean, the brain being scooped out through
the foramen magnum, soaked for a few days in water, and dried.
Every specimen should be carefully labelled with the scientific and
popular name of the animal, if known, and at all events, with the sex, the
exact locality at which it was procured, and the date.
For the i^urpose of making entire skeletons, select, if jDossible, adult
animals ; but the skulls of animals of all ages may be advantageously
collected.
Collectors of skins should always leave the skull intact. The common
practice of destroying its hinder part for the purpose of getting out the
brain is unnecessary, and greatly diminishes the value of the specimens.
Reptiles and Fishes. — -The following ' hints ' have been communicated
by Mr. Osbert Salvin, F.E.S., who collected these animals most successfully
in Guatemala : — ■
Almost any spirit will answer for this purpose, its fitness consisting in
the amount of alcohol contained in it. In all cases it is best to procure
the strongest possible, being less bulky, and water can always be obtained
to rediTce the strength to the requisite amount. When the spirit sold
retail by the natives is not sufficiently strong, by visiting the distillery
the traveller can often obtain the first runnings (the strongest) of the
still, which will be stronger than he requires undiluted. The spirit used
should be reduced to about proof, and the traveller should always be
provided with an alcoholometer. If this is not at hand, a little practice
will enable him to ascertain the strength of the spirit from the rapidity
with which the btibbles break when rising to the surface of a small
quantity shaken in a bottle. When the spirit has been used this test is
of no value. When reptiles or fish are first immersed, it will be foitnd
that the spirit becomes rapidly weaker. Large specimens absorb the
408 IITNTS TO TRAVELT-ERP,
alcohol vei'y speedily. The rapidity with which this ahsorption takes
place should be carefully watched, and in warm climates the liquid tested
at least every twelve hours, and fresh spirit added to restore it to its
. original strength. In colder climates it is not requisite to watch so
closely, but practice will show what attention is necessary. It will be
found that absorption of alcohol will be about proportionate to the rate
of decomposition. Spirit shoixld not be used too strong, as its effect is to
contract the outer surface, and thus, closing the pores, to prevent the
alcohol from penetrating through to the inner parts of the specimen. T/ie
principal point, then, is to ivatch that the strength of the spirit does not get
heIon> a certain p)oint luhile the specimen is absorbing alcohol when first put in.
It will be found that after two or three days the spirit retains its strength :
when this is the case, the specimen will be perfectly preserved. Spirit
should not be thrown away, no matter how often used, so long as the
traveller has a reserve of sufficient strength to bring it back to its requisite
strength.
In selecting specimens for immersion, regard must be had to the
means at the traveller's disposal. Fish tip to 9 inches long may be placed
in spirit, with simply a slit cut to allow tlie spirit to enter to the entrails.
With larger specimens, it is better to pass a long knife outside the ribs, so
as to separate the muscles on each side of the vertebrae. It is also as well
to remove as much food from the entrails as possible, taking care to leave
all these in. The larger specimens can be skinned, leaving, however, the
intestines in, and simply removing the flesh. Very large specimens pre-
served in this way absorb very little spirit. All half-digested food should
be removed from snakes and animals. In spite of these precautions,
specimens will often appear to be decomposing; but, by more constant
attention to re-strengthening the spirit, they will, in most cases, be
preserved.
A case (copper is the best), with a top that can be unscrewed and
refixed easily, should always be carried as a receptacle. The opening
should be large enough to allow the hand to be inserted ;■ this is to hold
freshly-caught specimens. When they have become preserved, they can
all be removed and soldered up in tin or zinc boxes. Zinc is best, as it
does not corrode so easily. The traveller will find it very convenient to
take lessons in soldering, and to be able to make his own boxes. If he
takes them ready made, they had best be arranged so as to fit one into
NATUEAL HISTOEY. 409
another before they are filled. When moTing aboiit, all specimens should
be wrapped in calico or linen or other rags to prevent their rubbing one
against the other. This should also be done to the specimens in the
copper case when a move is necessary, as well as to those finally packed
for transmission to Europe. These last should have all the interstices
between the specimens filled in with cotton-wool or rags. If a leak should
occur in a case, specimens thus packed will still be maintained moist, and
will keep some time witliout much injury. Proof spirit should be used
when the specimens are finally packed, but it is not necessary that it
should be fresh,
Land and Freshwater MoIIusca* By LiEUT.-CoL. H. H. Godwin-Austen,
F.E.s. — Always most abundant on limestone rocks. Search for under the
larger stones lying about the ground, and under fallen trees and logs in the
woods and forests. Will be generally found adhering to the surface of the
stone or wood. Many species are often only 005 inch in length, so that
very close examination is necessary. In damp sjDots, generally in ravines
with a northerly aspect, the dead leaves when damp with dew in the early
morning may be turned over one by one, and the under surface examined
for minute species, and larger species will be found very frequently
on the surface of the groimd below the layer of decaying vegetable matter.
Tear off the bark of decaying trees also. In the drier parts of the country
some species are only to be found among the roots of shrubs, and at con-
siderable depth ; by digging them out and shaking the earth on to paper,
small shells may be found on close examination. At a dry place like
Aden, I should expect to find most of the laud-shells alive in such a
habitat. Look well in caves in limestone on the damp surface of the
rock; some forms hide themselves under a coating of earthy matter.
Search also on damp moss and rock near waterfalls.
Some species will be found high up on the bushes and trees. This is the
habit of certain African forms especially ; not so in India. A very good
idea may at first be obtained of the land-shells of a country by the
examination of the beds of the streams, either along the highest flood-line,
or in the fine sand and mud where it collects in the bed ; such land-shells
will usually be old and bleached, but the living specimens will not be far off.
* Much iiseful information may be found in the ' Manual of the Mollusca,' by
S. P. Woodward, f.g.s., one of Weale's series : an admirable book in a small form.
410 HINTS TO TRAVELLERS.
The leaves and stems of water plants should be examined, and Conferv*
taken out of the water and well washed in a basin ; in this, and the mud
of ponds and still rivers, many minute shells may be found.
The best way of preserving minute shells is to put them into glass tubes
and use wool to stop them ; it is better than cork. Capital collecting tubes
can be made out of the smaller sorts of bamboo and the large grasses.
A certain number of every species (at least a dozen) should be preserved
in spirit for the sake of the anatomy. It is best to kill them first in water
and tlien put them into the spirit ; if this is not done they contract, so
that it is impossible to form any idea of the form of the mantle and
other parts, and they become so hard they are difficult to cut up.
A good method of keeping the small shells and slugs, especially in
spirit, is to put them into small tubes with labels, plug with wool, and
then place in a large jar, capable of holding three or four dozen such
small tubes.
Other small shells, ^ to f of an inch in diameter, may be put into pill-
boxes at once, for in a dry climate they very soon dry up. The very
large animals may be removed by boiling them in water, but when time
does not admit of attending to the cleaning of the shells, species such as
unios may be put into empty soup-tins and then filled up with dry
sand.
It is very important to make a few notes on the colour of the animal,
attaching a number for reference on the box or in the tube, and the
operculum, when present, should always be jjreserved.
With respect to slugs, note flie surface of the mantle, and always the
form of the extremity of the foot, whether pointed or provided with a
mucous pore; and again the lobes of the mantle. Preserve them in spirit
as above. Drawings from the living animal are invaluable, and should be
made if possible. Very little is known of the Asiatic forms ; they are of
much interest, and have been very little collected.
Insects. — Many of the most local and interesting insects of a country
are not to be found without a knowledge of their habits, and some are
nocturnal. In wooded and mountainous countries they must be searched
for in dead wood, luider logs, stones, fallen fruit, or moss, in folded leaves,
on sandy river banks, and under shingle, aboiit roots of herbage, in small
dead vertebrated animals, &c., &c. The best way of forming a collection
is to pin and set out the captures of each day before retiring to rest, and,
NATURAL HISTORY. 411
after drying them, to store the specimens in air-tight corked boxes. It is
only thns that good museum specimens can be obtained, and the colours
and fine hairy clothing with which many species are furnished preserved.
But on a journey of exploration this is quite impracticable, and all
travellers, including professional natural history collectors, now adopt
more summary and compact methods ; laying all the hard-bodied tribes
in prepared sawdust, and folding all the delicate-winged species in small
triangular paper envelopes. The former class should be collected in broad-
mouthed bottles, containing a minute piece of cyanide of potassium, or in
insect " killing bottles," as described in the foot-note at p. 398, it being
necessary to kill them speedily, to prevent their mutilating each other and
destroying their value as sijecimens. On reaching camp the contents should
be shaken out (into boiling water if not already killed), and then placed in
boxes, between layers of large-grained, or sifted and well-dried, sawdust.
. The under side of the lid of the box should be moistened with carbolic
acid, which will prevent the attacks of insects or moisture, and the sawdust
also sprinkled, but so as not to touch the specimens, the colours of which
would be tarnished by the acid. When the box is filled the lid may be lightly
nailed down, and it is then ready for transmission home. In collecting
ants, it is necessary to open nests at the time of swarming, and to secure
the winged individuals, as well as the wingless workers of various sizes,
of each species, the whole set being kept together and duly labelled. To
facilitate this, the set may be lightly gummed on cardboard before placing
them in sawdust. The more delicate-winged insects, such as butterflies,
moths, dragon-flies, &c., should be killed by pressing the breast under-
neath the wings with thumb and forefinger (taking great care not to
injure the wings), and then drojiping them with closed wings each into
its paper envelope (a supi3ly of which is to be taken on every excursion) ;
on reaching camp the envelopes, thus filled each with its specimen,
should be packed, without pressing them too tightly, in. boxes. Spiders
and Crustacea, land and fresh-water, may be collected in bottles con-
taining spirit, where they may remain ; but spirits should not be used
for any other class of insects, except in the case of si^ecimens intended
for dissection of the internal parts, as alcohol distorts the forms and
destroys the colours and pubescence.
Mountain travellers wiU have many opportunities of obtaining valuable
specimens of insects, but they cannot be expected to carry the usual
412 HINTS TO TRAVELLERS.
relatively bulky collecting apparatus, Tlie poison-bottlo must be small
enougli to go into the waistcoat pocket, and the traveller should bo pro-
vided with a number of little "self-opening" tin toxes, ready filled with
sawdust, and a particle of naphthalin. Each box should be reserved for
the insects found on one day, or in one locality, and duly lalx.lled outside
and inside. It is impossible in the narrow limits of a mountaineer's tent,
and with the little time at his disposal, to j^ack insects in layers in a
larger box, or to make any of the arrangements wliich a professed
naturalist is accustomed to.
Botanical Collecting. By the late J. Ball, f.r.s. — To obtain good
specimens of dried plants iu a condition serviceable to scientific men, the
following are the chief points to be observed : —
1. Selection of Specimens. — The object is to give as much information
as possible respecting the plant which it is intended to collect. Small
plants not exceeding 16 inches in height should be collected entire ivith
the roots. Slender plants of greater dimensions may be folded to the
same length, and may often be collected entire. Of larger plants, shrubs
and trees, the object is to show as much as possible of the plant within
the limit of the size of your drying paper. As an universal rule, both
the flower and fruit (seed-vessel) should, if possible, be preserved. Of
those plants whereon the male and female flowers grow separately,
specimens of both should, if possible, be collected.
2. Conveyance of Specimens to Camp or Station. — Tin boxes made for the
purpose are generally used in Europe for carrying botanical specimens
until they can be placed in the drying press. They answer sufficiently
well in cool weather, but in hot countries specimens are often partly
withered before they can be laid out ; and a rough portfolio, into which
the plants can be put when (or soon after) they are gathered, is iiuich to
be preferred.
Such a portfolio is easily prepared with two sheets of millboard con-
nected by an endless tape, so as to be easily slung over the shoulder;
between these about thirty or forty sheets (60 to 80 folds) of thin soft
(more or less bibulous) paper may be carried and kept in place by a strap
or piece of twine. With two such i;)ortfolios a traveller can carry as many
plants as it is possible to collect with advantage in a day. As soon as
possible after being gathered, the specimens should be laid roughly
between the sheets of paper : except in the case of delicate flowers, no
NATURAL HISTORY.
413
special care is needed, and no harm comes of two or three being put
together.
3. The Drying Press. — The great object, both to secure good specimens
and to save labour and weight of paper, is to get the plants dried quickly ;
and for this one of the first conditions is to lose as little time as possible.
When practicable, the specimens should always be put in the press on
the same day on which they are gathered. The press should be made
with two outer gratings of iron wire ; the outer frame of strong wire,
about a quarter of an inch in diameter — the size being that of the paper
used. Between these the paper is laid. As to the choice of drying paper,
the general rule is, that the coarser it is the better, provided it be quite
or nearly quite free from size.
T
1
1
1
1
1 \
_ 1 1
I
1,
To enable the plants to dry quickly, the traveller should be provided
with light wooden gratings of the same size as the drying jiaper. I
think the size 18 inches x 12 inches is quite large enough. The iron
wire outer gratings may with advantage be a quarter of an inch longer
and broader to save the edges of the wooden gratings.
These should be made of light laths fastened with a few nails (all the
414
HINTS TO TRAVELLERS.
better if these are of copper), the interstices should be rather less than
three-quarters of an inch, at all events not more. Their use is to allow
the air to circulate through the pile of plants tliat are Ijeing dried. One
should be inserted at each interval of about two inches (counting the
drying paper and the plants laid out for drying), and when this is done
the parcel may with advantage be exposed to the sun or placed near a fire,
as the case may be. In dry warm climates, the majority of plants may be
dried in the course of a few days, and will be fit to pack up, without any
need of changing the drying paper in which they were originally placed ;
but in damp weather, and in regard to plants of thick fleshy foliage, it is
usually necessary to change the paper more than once before the specimens
are thoroughly dry.
The pile of paper, with plants between each five or six thicknesses ot
paper, and gratings at intervals of about two inches, should be squeezed
1 li II II M II 1 r !
1 1 1 1 ! r 1 1' :' 1' li 1' 1
ii II II r II ii ii 11 II 1
1 It II II 1, II II II II Ii 1
1 II II II II Ii II II II II 1
1 II II 11 II II II II |i 1' 1
b — a D p □ Li □ □ D d
GRATING SEEN FROM THE EDGE.
GRATING SEEN' FROM ABOVE.
between the outer (iron) gratings by means of two strong straps. Too
much pressure is not desirable. For a pile ten or twelve inches thick,
the parcel may be i^ulled nearly as tight as a moderate man can do
it; but in proportion as the thickness is less, the pressure should be
moderated.
Plants with fleshy leaves are very difficult to dry well. The best way
is to dip them in -water quite boiling for a minute or less, then to lay
them between a few sheets of drying paper with slight pressure, merely
to remove the exterior moisture, and then place them (when externally
dry) in the drying press. Plants collected in rain should be treated in a
similar way to remove outer moisture before it is attempted to dry them.
4. When once dry, plants may be packed away between paper of almost
any kind. Old newspapers answer very well. The only precaution
needed is to preserve them from insects.
NATURAL HISTORY. 415
The chief trouble in collecting plants is to get the paper already-
used thoroughly dry before it is again employed. The best resource in
dry climates is to stretch cords and hang these papers exposed to sun
and air. Artificial heat must be resorted to in wet seasons, but the
process is then slow and troublesome.
For a traveller wishing to make large collections, the time consumed
in changing the paper in which the plants are dried becomes an im-
portant consideration. I have adopted with advantage a suggestion of
the late Professor A. Gray to use, instead of ordinary drying paper,
sheets, cut to the proper size, of the paper-felt which is Txsed for laying
under carj^ets. The specimens when originally laid out for drying are
placed within sheets of thin paper without size, such as filtering paper,
and as a rule these do not need to be changed. One sheet of felt-paper
is generally sufficient between each layer of plants, and the operation of
changing the paper is very quickly effected.
It is an important rule to note the locality where the specimens have
been collected, with the date. If proper care be taken to keep together
all the specimens collected at the same time, it is not necessary to place a
separate scrap of paper within each sheet ; but it is advisable to do this
when the dried specimens are packed for transmission home.
5. Seeds. — Travellers may easily make valuable contributions to our
knowledge of the vegetation of distant countries by preserving seeds of
remarkable and unusual plants. The only precautions necessary are, to
select seeds that are fully ripe ; if enclosed in a seed vessel, or covering of
a succulent character, to take care that this is thoroughly dried before
they are packed ; and that they are preserved from moisture during the
homeward voyage. Small seeds may be enclosed in paper, the larger
kinds in canvas bags, and the whole wraj^ped in a piece of oiled cloth.
It is very desirable to keep each description of seed sejiarate, and to
note the place where it was gathered, with indications of altitude, soil,
and climate.
6. Bulls. — These are easily obtained, but, as a rule, they should be
taken only at the end of the growing season, and kept until the leaves
are quite withered. They should be packed dry in a small box with
shavings, or other elastic stuffing. The same treatment will suit the
pseudo-bulbs of some orchids.
7. Fleshy Tubers. — These and thick rhizomes may best be sent in boxes,
416 HINTS TO TRAVELLERS.
wrapped in slightly moist materials, si;ch as cocoa-nut fibre, peat, or
leaf mould.
8. LivirKj riants. — As a general rule, these require to he established in
pots or boxes for some time before licing packed for transmission. They
travel best in wliat are called Wurdian cases; but an ordinary wooden
box covered with a glass toi"), and with sufficient moisture in the soil and
air to prevent excessive evaporation, is found to answer the purpose.
The cases should be kept on deck under some protection from the direct
heat of the sun. Tropical plants should be despatched so as to reach
England during the summer months. At other seasons they are liable
to perish from cold.
9. Succulent Plants, such as cacti, aloe, houseleeks, &c., survive for a
long time if packed without earth in a perfectly dry box, with sufficient
openings for ventilation.
10. Sqaall plants with woody roots and cuttings of larger species of
plants from the north or south temperate zones often travel successfully
when merely packed with a little soil, slightly moist, about the roots, and
a wrapping of damp moss, or similar substance, tied up in thick paper or
canvas. There is, however, much risk of failure in these cases where, on
the homeward voyage, it is necessary to pass through the tropics.
As a general rule, plants are more often injured by excess of moistui-e
than by being sent too dry.
It is desirable to make use of every favourable opportunity for sending
botanical collections of all kinds to England, as in hot countries they are
always exposed to risk of injury.
It is scarcely necessary to mention that living plants, as well as seeds
and bulbs, should be placed in the hands of skilful gardeners after
reaching this country. The chance of preserving interesting specimens
is commonly much greater when they are sent to botanic gardens than
when entrusted to private cultivators. In all cases information as to the
soil and climate of the native home of the plant is a necessary guide to
proper treatment.
Fossils. — The collection of fossils and minerals (except in the case of
the discovery of new localities for valuable metals) is not to be recom-
mended to the traveller, if he is not a geologist. Fossils from an unex-
plored country are of little use unless the nature and order of super-
position of the strata in which they are found can be at the same time
NATURAL HISTORY. 417
investigated. In the cases, however, of recent alluvia! strata or the sup-
posed beds of ancient lakes, or deposits in caves, or raised sea-heachr s
containing shells or bones of vertebrate animals, the traveller will do
well to bring away specimens if a good opportunity offers. If the plan
of the expedition includes the collection of fossil remains, the traveller
will, of course, provide himself with a proper geological outfit, and obtain
the necessary instructions before leaving Europe. (See Section YII.)
General Bcmarks. — All collections made in tropical countries should lie
sent to Europe with the least possible delay, as they soon become de-
teriorated and spoilt unless great care be bestowed upon them. Dry skins
of aniinals and birds may be packed in wooden cases well lined and
padded with brown paper. Shells and skulls should be provided with
abundance of elastic padding, such as cotton. Boxes containing pinned
insects and Crustacea should be packed within larger boxes and sur-
rounded by an ample bed of hay or other light dry elastic material; un-
less this last point is carefully attended to, it is doubtful whether such
collections will sustain a voyage without more or less serious injury.
Ohaerv'itiona of Habits, &c. — Travellers have excellent opportunities of
observing the habits of animals in a state of nature, and these 'Hints'
would be very deficient were not a few remarks made upon this subject.
To know what to observe in the economy of animals is in itself an accom-
plishment which it would be unreasonalile to expect the general traveller
to possess, and without this he may bring home only insignificant details,
contributing but little to o\ir stock of real knowledge. One general rule,
however, may be ke])t always present to the mind, and this is, that any-
thing concerning animals which bears upon the relations of species to
tlieir conditions of life is well worth ob.serving and recording. Thus, it
is important to note the various enemies which each species has to con-
tend with, not only at one epoch in its life, but at every stage from birth
to death, and at different seasons and in dilferent localities. The way in
which the existence of enemies limits the range of a species should also
be noticed. The inorganic influences which inimically affect species,
especially intermittently (such as the occurrence of disastrous seasons),
and which are likely to operate in limiting their ranges, are also in-
portant subjects of inquiry. The migrations of animals, and especially
any facts about the irruption of species into districts previously unin-
habited by them, are well worth recording. The food of each species
2 F
418 HINTS TO TRAVELLERS.
should bo noticed, and if any cliange of customary food is observed, owing
to tlic failure of the supply, it should be carefully recorded. The use
in nature of any peculiar physical conformation of animals, the object
of ornamentation, and so forth, should also be investigated whenever
opportunity occurs. Any facts relating to the interbreeding in a state
of nature of allied varieties, or the converse— that is, the antipathy to
intercrossing of allied varieties — would be extremely interesting. In
short, the traveller should bear in mind that facts having a philosophical
bearing are much more important than mere anecdotes about animals.
To observe the actions of the larger animals, a telescope or opera-glass
will be necessary. The traveller should bear in mind, if a microscope is
needed in his journey, that by unscrewing the tubes of the telescope in
which all the small glasses are contained, a compound microscope of
considerable power may be produced.
( 419 )
IX.
ANTHEOPOLOGY.
BlJ E. B. TyLOR, D.C.L., F.R.S.
The characters of men's bodies and minds being matters of common
observation, Europeans not specially trained in anthropology, who have
happened to be thrown among little-known tribes, often bring home
valuable anthropological information. Though explorers, traders, and
colonists have maie their way into almost every corner of the earth, it is
surprising to find how many new facts may still be noted down by any
careful observer. If familiar with anthropological methods, he will, of
course, observe more and better. The hints here given will serve to
draw attention to interesting points which might otherwise be overlooked.
Directions for such investigation, drawn np in much greater detail, will
be found in the small British Association manual entitled: 'Notes and
Queries on Anthropology ' (Anthropological Institute, 3, Hanover
Square, W.).
Physical Characters. — On first coming among an unfamiliar race, such
as the Negroes, the traveller is apt to think them almost alike, till after a
few days he learns to distinguish individuals more sharply. This first
impression, however, has a value of i's own, for what he vaguely per-
ceived was the general type of the race, which he may afterwards gain
a more perfect idea of by careful comparison. Among tribes who for
many generations have led a simple uniform life and mixed little with
strangers, the general likeness of build and feature is very clof e, as may
be seen in a photograph of a party of Caribs or Andamancrs, whose
uniformity contrasts instructively witli the individualised faces of a party
of Europeans. The consequence is tl:at a traveller among a rude people,
if he has something of the artist's faculty of judging form, may select
grouiDS for photography which will fairlv represent the tvpe of a whole
' 2 F 2
420 HINTS TO TRAVELLERS.
tribe or nation. While such portrait-groups are admirable for giving tlio
general idea of a race, characteristic features belonging to it should be
treated separately. For instance, to do justice to the Tartar eye or the
Australian forelicad, the individual feature must be carefully sketched
or photographed large.
How dccei3tive mere unmeasured impressions of size may be is shown
by the well known example of the Patagonians, who, though really only
tall men (averaging 5 feet 11 inches), long had the repxitation of a race of
giants. Such measurements as any traveller can take with a measuring-
tape and a three-foot rule with sliding square are good if taken with
proper precautions. As the object of the anthropologist is to get a
general idea of a race, it may be in some respects misleading to measure
at random one or two individuals, who are perhaps not fair specimens-
If only a few can be measured, they should be selected of ordinary average
baild, full-grown but not aged. What is much better is to measure a
large number (twenty to fifty) of persons taken indiscriminately as they
come, and to record the measurements of each with sex, age, name, locality,
&c. Such a table can afterwards be so classified as to show not only the
average or mean size, but the proportion of persons who vary more or
less from that mean size ; in fact, it represents on a small scale the
distribution of stature, &c., in the whole people. Gigantic or dwarfish
individuals, if not deformed, are interesting as showing to what extremes
the race may rim. The most ordinary measurements are height, girth
round chest, fathom or length of outstretched arms, length of arm ivvm.
shoulder and leg from hip, length of hand and foot. The traveller may
find that such measuring of another race shows very dilTerent stature and
girth from that of his OM^n companions, who, if they are well grown Euro-
peans, may stand 5 feet 8 inches to 6 feet, and measure 84 to o6 inches
round the chest. Beyond this, he will find that the relative proportions
of parts of the body differ from those he is accustomed to. An example
of this is seen by placing Europeans and regroes side by side, and
noticing how much nearer the knee the nrgro's finger-tips will reach.
It will be found that body measurement needs skill in taking the corre-
sponding points, and in fact all but the simplest measures require some
knowledge of anatomy. This is especially the case with skuU measure-
ments. There are instruments for taking the dimensions of the living
head, and with care and practice the untraimd observer may get at
ANTHROPOLOGY. 421
some of the more conspicuous, such as the rehitive lengtli and width
of the skull as taken by hatters. This roughly indicates the marked
difference between dolichokephalic or long-headed peoples, like the
African negro, and brachykephalic or short-headed peoples, like the
Kalmuks and other Tartars. Attention should be paid also to the degree
of prognathism or projection of jaw, which, in some races, as the
Australian, gives a " muzzle " unlike the English type. Where practicable,
native skeletons, and especially skulls, should be sent home for accurate
examination. How far this can bo done depends much on the feeling of
the people; for while some tribes do not object to the removal of bones,
especially if not of their own kinsfolk, in other districts it is hardly safe
to risk the displeasure of the natives at the removal of the dead— a
feeling which is not only due to affection or respect, but even more to
terror of the vengeance of the ghosts whose relics have been disturbed.
In describing complexion, such terms as " brown " or " olive," so often
used without further definition in books of travel, are too inexact to be of
use. Broca's scale of colours (see the Anthropological ' Notes and Queries ')
gives means of matching the tints of skin, hair, and eyes ; if this is not
forthcoming, the paint-box should be used to record them. Among rude
tribes, the colour of the skin is often so masked by paint and dirt that
the subject must be washed to see the real complexion. Hair is also an
important race-mark, varying as it does in colour from flaxen to black, and
also in form and size of the hairs ; for instance the American Indian's
coarse straight hair seems almost like a horse's tail in comparison with
the Bushman's hair with its natural frizz of tiny spirals. Locks of hair
should therefore be collected. The traveller, however, will often find
some difficulty in getting such specimens, from the objection prevalent in
the uncivilised world of letting any part of tlie body, such as hair and nail-
clippings, pass into strangers' hands lest they should be used to bewitch
their former owner. Even in such countries as Italy, to ask for a lock of
a peasant-girl's hair may lead to the anthropologist being suspected of
wishing to practise love-charms on her.
Differences of temperament between nations are commonly to be
noticed ; for instance, in comparing the shy and grave Malays with the
boisterous Africans. It is an interesting but difficult problem how far
such differences are due to inherited race-character, and how far to such
social influences as education and custom, and to the conditions of life
422 HINTS TO TRAVELLERK
boing chcortiil or depressing. Nor has it yet been determined bow far
emotions are differently expressed by different races, so that it is worth
while to notice particularly if their smiling, laughing, frowning, weeping,
blushing, &c , differ perceptibly from ours. The acuteness of the senses
of siglrt, hearing, and smell, among wild peoples is often remarkable, but
this subject is one on which many accounts have been given which
require sifting. The skill of savages in path-finding and tracking
depends in great measure on tliis being one of their most necessary arts
of life, to which they are trained from childhood, as, in an inferior degree,
gipsies are with us. The native hunter or guide's methods of following
the track of an animal, or finding his own way home Ijy slight signs, such
as bent twigs, and kee])iug general direction through the forest by the sky
and the shtltered sides of the trees, are very interesting, though when
learnt they lose mvich of their marvellous appearance. The testing of the
mental powers of various races is an interesting research, for which good
opportunities now and then occur. It is established that some races aie
inferior to others in volume and com])lexity of brain, Australians and
Africans being in this respect below Europeans, and the question is io
determine what differences of mind may correspond. Setting aside the
contemptuous notions of uneducated Europeans as to the minds of " black-
fellows ■' or " niggers," what is required is, to compare the capacity of two
races under similar circumstances. This is made difficult by the fact
of different training. For instance, it would not be fair to compare the
European sportsman's skill in woodcraft and hunting with that of the
native hunter, who has done nothing else since childhood; whil\ nn
the other hand, the European, who has always lived among civilised
people, owes to his education so much of his superior reasoning powers,
that it is mostly impossible to get his mind into comparison with a
savage's. One of the best tests is the progress made by native and
European children in colonial or mi.ssionary schools, as to which it is
commonly stated that children of African or American tribes learn as fast
as or faster than European children up to about twelve, but then fall
behind. Even here it is evident that other causes besides mental power
may be at work, among them the discouragement of the native children
when they become aware of their social inferiority. The subject is one
of great imi^ortauce, both scientifically and as bearing on practical
government.
ANTHKOPOLOGY. 423
Both as a matter of anthropology and of practical politics, the
suitability of particiilar races to particular climates is of great interest ;
sometimes this depends on one race being free from a disease from which
another suffers, as in the -well-known immunity of negroes from yellow
fever. Or it may be evident that tribes have become acclimatised, so as
to resist influences which are deadly to strangers ; for instance, the
Khonds flourish in the hills of Orissa, where not only Europeans but
the Hindus of the plains sicken of the malaria in the unhealthy season.
That such peculiarities of constitution are inherited and pass into the
nature of the race, is one of the keys to the obscure problem of the
origins of the various races of man as connected with their spread over
the globe. As yet this problem has not passed much beyond the stage of
collecting information, and no pains should be spared to get at facts thus
bearing on the history and development of the human species. European
medical men in districts inhabited by uncivilised races have often made
important observations of this kind, which they are glad to communicate,
though being occupied with i^rofessional work they do not follow them
up. In all races there occur abnormal varieties, which should be ob-
served with reference to their being hereditary, such as Albinos, whose
dead-whiteness is due to absence of pigment from the skin. Even such
tendencies as that to the occiirrence of red hair where the ordinary
hue is black, or to melanism or diseased darkening of the skin, are worth
remark. It is essential to discover how far these descend from i^arents
to children, which is not the case with such alterations as that of the
Chinese feet, which, in spite of generations of cramping, continue of the
natural shape in the children.
Lamjuwje. — Before coming to actual language, remark may be made on
the natural communication of all races carried on by pantomimic signs
without spoken words. This is the " gesture language " to which we are
accustomed among the deaf-and-dumb, and which sometimes also comes
into practical use between tribes ignorant of one another's languages, as
on the American prairies. It is so far the same in principle everywhere,
that the explorer visiting a new tribe, having to make frequent use of
signs to supplement his interpreter, or to eke out his own scanty know-
ledge of the native language, soon adapts himself to the particular signs
in vogue. He will observe that, as to most common signs, such as asking
for food or drink, or beckoning or warning off a stranger, he understands
424 HINTS TO TRAVELLERS.
and is uudcrdtood quite naturally. Signs which are puzzling at first
sight will prove on examination to be intelligiblu. Some are imitative
gestures cut short to save trouble, or they may have a meaning which
was once evident, like the American Indian sign for dog, made by trailing
two forked fingers, which does not show its meaning now, but did so
in past times, when one principal occupation of tiie dog was to trail a
pair of tent-jDoles fastened on his back. Besides its practical use, the
gesture-language has much scientific interest from the perfect way in
which it exposes the working of the human mind, expressing itself by a
series of steps which are all intelligible. It wiU be particularly observed
that it has a strict syntax ; for instance, that the quality or adjective
must always follow the subject or substantive it is applied to. Thus,
" the white box " may be expressed by imitating the shape and opening
of a box, and then touching a piece of linen or paper to show its colour ;
but if the signs be i^ut in the contrary order, as in the English words,
the native will be perplexed. It is worth while, in countries where
gesture-language is regularly used, to note down the usual signs and their
exact order
In recording a vocabulary of a language not yet reduced to form in a
grammar and dictionary, the traveller may seek for equivalents of the
principal classes of words in his own grammar : verbs, substantives,
adjectives, pronouns, prepositions, &c. But the structure of the language
he is examining will probably differ from any he is familiar with, the
words actually used not coming precisely into these classes. The best
method is for the traveller to learn a simple sentence, such as, " the men
are coming," and to ascertain what changes will convert them into " the
men are going," " the womju are coming." He thus arrives at the real
elemjnts of the language and the method of combining them. Having
arrived at this point, he will be able to collect and classify current ideas,
such as the foUjwing: —
Actions -as stand, walk, sleep, eat, see, make, &c.
Natural Objects and Mements — as sun, moon, star, mountain, river, fire,
water, &i.
Man and other Animals — as man, woman, boy, girl, deer, buck, doe,
eagle, eagles, &c.
Farts of Body — as head, arm, leg, skin, bone, blood, &c.
ANTHKOPOLOGY. 425
Trees and Plants.
Numerals (noticing how far they extend, and whether referring to
fingers).
Instruments and Appliances — as spear, bow, hatchet, needle, pot, boat,
cord, house, roof, &c.
Arts and Pastimes— as pictui'e, paint, carving, statue, song, dance, toy,
game, riddle, &c.
Family Belationsliips (as defined by native custom).
Social and Leyal Terms — as chief, freeman, slave, witness, punishment,
fine, &c.
Religious Terms — as soul, spirit, dream, vision, sacrifice, penance, &c.
Moral Terms — as truth, falsehood, kindness, treachery, love, &c.
Abstract Terms, relating to time, space, colour, shape, power, cause. &c.
The interjections used in any language can be noted, whether they are
organic expressions of emotion, like oh ! ugh 1 ur-r-r I or sounds the nature
of which is not so evident. Also imitative words which name animals from
their cries, or express sounding objects or actions by their sounds, are
common in all languages, and strike the stranger. Examples of such are
kah-kah for a crow, twoiik for a frog, pututu for a shell-trumpet, haitschu
for to sneeze. When such imitative words are noticed passing into other
meanings where the connection with sound is not obvious, they become
interesting facts in the development of language ; as, to take a familiar
example from English, the imitative verb io puff becomes a term for light
pastry and metaphorically blown-up praise.
It is only when the traveller has a long or close acquaintance with a
tribe, that he is able to .deal satisfactorily with the vocabulary and
structure of their language. To be able to carry on a conversation in
broken sentences is not enough, for an actual grammar and dictionary is
required to enable philologists to make out the structure and affinities
with other languages. It used to be customary to send out English lists
of thirty or forty ordinary words to have equivalents put to them in native
languages. As every detail of this kind is worth having, these lists
cannot be said to be quite worthless, but they go hardly any way toward
what is really wanted. They are liable to frequent mistakes, as when
the barbarian, from whom the white man is trying to get the term '' foot,"
answers with a word meaning " my leg," which is carefully taken down
426 HINTS TO TRAVELLERS.
and printed. Such poor vocabularies cannot even be relied on to show
whether a language belong.s to a particular family, for the very word
which seems to prove this may be borrowed. Thus, in various African
vocabularies, there appears the word snpun (or sometliing similar) with
the mej'ining of soap ; but this is a Latin word which has spread far and
wide from one country to another, and proves nothing as to original
connexion between languages which have adopted it. While it is best
not to under- rate the diflBculty of collecting such information as to a
little-known dialect as will be really of service to i)liilology, it must be
remembered that travellers still often have opportunities of i)reserving
relics of languages, or at any rate special dialects, which are on the point
of dying out unrecorded. Where no proper grammar and dictionary
has been compiled, it is often possible to find some European or some
interpreter fairly conversant with the language, with whose aid a voca-
bulary may be written out and sentences analysed grammatically, which,
when read over to intelligent natives and criticised by them, may be
worked into good linguistic material. It is worth while to jjay attention
to native names of i^lants, minerals, &c., as well as of places and persons,
for these are often terms carrying significant meaning. Thus ipecarAianha
is stated by Martius to be i-pe-caa-guene, which in the Tupi language of
Brazil, signifies " the little Avayside plant which makes vomit."
Arts and Sciences. — The less civilised a nation is, the ruder are their
tools and contrivances; but these are often worked with curious skill in
getting excellent results with the roughest means. Stone implements
have now been so siipplanted by iron that they are not easily found
in actual use. If a chance of seeing them occurs, as, for instance,
among some Californian tribe, who still chip out arrow-heads of obsidian,
it is well to get a lesson in the curious and difficult art of stone-imple-
ment making. In general, tools and implements differing from those of
the civilised world, even down to the pointed stick for root-digging and
planting, are worth collecting, and to learn their use from a skilled hand
often brings into view remarkable peculiarities. This is the ease with
many cudgel- or boomerang-like weapons thrown at game, slings or sj^ear-
throwers for hurling darts to greater distances than they can be sent by
hand, blow-tubes for killing birds, and even the bow-and-arrow, which in
northern Asia and America shows the ancient Scythian or Tartar form,
having to be bent inside out to string it. Though fire is now practically
ANTHROPOLOGY. 427
made almost every where with flint and steel or lucifers,in some districts^
as South Africa or Polynesia, jjeople still know the primitive method of
fire-making by rubbing or drilling a pointed stick into another piece of
wood. Europeans find difficulty iu learning this old art, which requires
some knack. As is well known to sportsmen, different districts have
their special devices for netting, trapping and other ways of taking game
and fish, some of which are well worth notice, such as spearing or shooting
fish under water, artificial decoys, and the spring-traps set with bent
boughs, which are supposed to have first suggested the idea of the bow.
While the use of dogs in hunting is found in most parts of the world,
there is the utmost variety of breeds and training. Agriculture in its
lower stages is carried on by simple i^rocesses; but interesting questions
arise as to the origin of its grain and fruits, and the alterations in
them by transplanting into a new climate and by ages of cultivation.
Thus iu Chili there is found wild what botanists consider the original
potato ; but while maize was a staple of both Americas at the time of
Colombus, its original form has no more been identified than that of
wheat in the Old World. The cookery of all nations is in principle known
to the civilised Eurojiean ; but there are special preparations to notice,
such as bucaning or drying meat on a hurdle above a slow fire, broiling
kibabs or morsels of meat on the skewer in the East, &c. Many peoples
have something peculiar in the way of beverages, such as the chewed
Polynesian 'kav(t, or the South American mate sucked through a tube.
Especially fermented liquors have great variety, such as the kumiss from
mare's milk in Tartary, the pomhe or millet-beer of Africa, and the kvass
or rye-beer of Russia. The rudest pottery made by hand, not thrown
on the wheel, is less and less often met with, bx;t ornamentation trace-
able to its being moulded on baskets is to be seen ; and calabashes, joints
of bamboo, and close-plaited baskets, are used for water- vessels, and even
to boil in. Among the curious processes of metal-working, contrasting
with those of modern Europe, though often showing skill of their own,
may be mentioned the simple African smelting-forge by which iron-ore is
reduced with charcoal in a hole in the ground, the draught being sup-
plied by a pair of skins for bellows. In the far East a kind of air-pump
is used, of which the barrels are hollowed logs. The Chinese art of
patching cast-iron Avith melted metal surprises a European, and the
Hindu manufacture of native steel {wuvtz) is a remarkable process. No
428 HINTS TO TRAVELLERS.
nation now exists absolutely in the Bronze Age, but this alloy still
occupies something in its old place in Oriental industry. As an examjile
of the methods stiU to be seen, may be mentioned the Burmese bell-
founding, which is done, not in a hollow mould of sand, but by what
in Europe is called the cire perdue process, the model of the bell being
made in bees-wax and imbedded in the sand-mould, the wax being melted
and the hot metal taking its place. The whole history of machinery is
open to the traveller, who still meets with every stage of its development,
from savagery upward. He sees, for instance, every tilling implement
from the stake with iire-hardened point, and the hoe of crooked branch,
uj) to the modern forms of plough. In like manner he can trace the
line from the rudest stone-crushers or rubbers for grinding seed or
grain up to the rotating hand-mills or querns still common in the East,
and surviving even in Scotland. From time to time somi special con-
trivance may be seen near its original home, as in South America the
curious plaited tube for wringing out the juice from cassava, or the net
hammock which still retains its native Haitian name hamaca. Archi-
tecture still preserves in different regions interesting early stages of
development, from the rudest break winds, or beehive huts of wattled
boughs, up to houses of logs and hewn timber, structures of mud and
adobes, and masonry of rough or hewn stone. Even the construction of
the bough-hut or the log-house often has its peculiarities in the arrange-
ments of posts and rafters. Ami:)ng the modes of construction which interest
the student of architectural history is buiLling with rough unhewn stones.
Many examples of "rude stoue moauments" are to be seen on our own
moors and hills. The most familiar kinds are dolmens (i.e. " table-stones "),
formed by upright stones bearing a cap-stone ; they were bi;rial-places,
and analogous to the cists or chambers of rough slabs within burial-
m Hinds. Less clearly exijlicable are the single standing-stones or m>:nhirs
{i.e. " long-stones "), and the circles of stones or cromlechs. Ancient and
obscure in meaning as such monuments are in Europe, there are regions
where their construction or use comes down to molern times, especially
in India, where among certain tribes the deposit of ashes of the dead in
dolmens, the erection of menhirs in memory of great men, and even
sacrifice in stone circle?, are well-known customs. The traveller may
also sometimes have opportunities of observing the ancient architectural
construction by fitting together many-sided stones into what are some-
ANTHROPOLOGY. 429
times called Cyclopean walls, a kind of building which feems to have
preceded the use of squared blocks, fastened together with cl- mps or with
mortar. Vaulting or roofing by means of courses of stones projecting
inwards one course above t-ie other (much as children build with their
wooden bricks), so as to form what architects call a " false arch," is an
ancient mode of constniction found in various parts of the world where
tlie '• true arch " with its keystone has not superseded it. It often
appears that rude nations have copied the more artistic buildings of
higher neighbjurs, or inherited ancient architectural traditions. Thus
traces of Indian architecture have found their way into the islands of
the Eastern Archipelago, and hollow squares of mud-built houses round
a courtyard in northern Africa have their pLm from the Asiatic caravan-
serai. In boat-building some primitive fo;ms, as the " dug-out," hollowed
by the aid of fire from a tree-trunk, and the bark-canoe, are found in
such distant regions that we cannot gui ss where they had their origin.
When, however, it comes to the outrigger-canoe, this belongs to a district
which, though very large, is still limited, so that we may at least guess
whereabouts it first came into use, and it is important to note every
island to which it has since travelled. So there is much in the peculiar
build and rig of Malay prahus, Chinese junks, &c., which is worth noting
as part of the history of ship-building. This may suffice to give a general
idea of the kind of information as to the local arts which it is worth
while to collect, and to illustrate by drawings and photographs of objects
too large to bring away.
Naturally, nations below the upper levels of culture have little or no
science to teach us, but many of their ideas are interesting as marking
stages in the history of the human mind. Thus, in the art of counting,
which is one of the foundations of science, it is common to find the
primitive method of counting by fingers and toes still in practical use,
while in many languages the numeral words have evidently grown up out
of such a state of things. Thus lima, the well-known Polynesian word
for five, meant " hand," before it passed into a numeral. All devices for
counting are worth notice, from the African little sticks for units and
larger sticks for tens, up to the ball- frames with which tlie Chinese and
Russian traders reckon so rapidly and correctly. It is a sign of lowness
in a tribe not to use measures and weights, and where these appear in a
rough way, it is interesting to discover whether vague lengths, siich as
430 HINTS TO TRAVELLERS.
finger, foot, pace, arc used, or wlicthcr standard measures and weights
have come in. If so, these should be estimated according to our standards
with as much accuracy as possible, as it may thus become possible to
ascertain their history. In connection with this comes the question of
money; as to whether commerce is still in the rudimentary stage of
exchanging gifts, or has passed into regular barter, or risen to regular
trade, with some sort of money to represent value, even if the circulating
medium be only cowries, or bits of iron, or cakes of salt, all which are
current money to this day in parts of Africa. Outside the present higher
civilisation, more or less primitive ideas of astronomy and LM'OL'raphy will
be found to prevail. Among tribes like the American Indians the obvious
view suggested by the senses still prevails, that the earth is a flat round
disc (or sometimes square, with four quarters or winds) overarched V>y a
solid dome or firmament, on which the sun and moon travel — in inland
countries going in and out at holes or doors on the horizon, or, if the sea
bounds the view, rising from and plunging into its waves at sunrise and
sunset. These early notions are to us very instructive, as they enable us
to realise the conceptions of the universe which have come down to us
in the ancient books of the world, but which scientific education has tip-
rooted from our own minds. With these cosmic ideas are found among
the lowest races the two natural periods of time, namely, the lunar month
and the solar year, determined by recurring winters, sTimmcrs, or rainy
seasons. Such tribes divide the day roughly by the sun's height in the
sky, but among peoples civilised enough to have time-measures and the
sun-dial, there is a tolerably accurate knowledge of the sun's place at
the longest and shortest days, and, indeed, throughout the year. Tlie
astronomy of such countries as India has been of course described by
professional astronomers ; but among ruder nations there is still a great
deal unrecorded — for instance, as to the constellations into which they
map out the heavens. This likening stars and star-groups to animals and
other objects is almost univer.sal among mankind. Savages like the Aus-
tralians still make fanciful stories about them, as that Castor and Pollux
are two native hunters, who pursue the kangaroo (Capella) and kill him
at the beginning of the hot season. Such stories enable us to understand
the myths of the Classical Dictionary, while modern astronomers keep up
the old constellations as a convenient mode of mapping out the sky. As
to maps of the earth, even low tribes have some notion of their principle.
ANTHROPOLOGY. 431
and can roughly draw the cliart of their own district, which they shoukl
be encouraged to do. Native knowledge of natural history differs from
much of their rude science in its quality, often being of great positive
value. The savage or barbarian hunter knows the animals of his own
region and their habits with remarkable accuracy, and inherited expe-
rience has taught him that certain plants have industrial and medicinal
uses. Thus, in South America the Europeans learnt the use of India-
rabber or caoutchouc, which the native tribes were accustomed to make
into vessels and playing-balls, and of the Peruvian bark or cinchona,
which was already given to patients in fever.
Here a few words may be said of magic, which, though so utterly futile
in practice, is a sort of early and unsuccessful attempt at science. It is
easy, on looking into the proceedings of the magician, to see that many of
them arc merely attempts to work by false analogy or deceptive associa-
tion of ideas. The attempt to hurt or kill a person by cutting or piercing
a rude picture or image representing him, which is met with in all the
four quarters of the globe, is a perfect example of the way in which
sorcerers mistake mere association of ideas for real cause and effect.
Examined from this point of view, it will be found that a large pro-
portion of the magic rites of tlie world will explain their own meaning.
It is true that this is not the only principle at work in the magician's
mind ; for instance, he seems to reason in a loose way that any extra-
ordinary thing will produce any extraordinary effect, so that the peculiar
stones and bits of wood which we should call curiosities become to the
African sorcerer powerful fetishes. It will often be noticed that arts
belonging to the systematic magic of the civilised world, which has its
source in Babylon and Egypt, have found their way into distant lands
more readily indeed than useful knowledge, so tliat they may even be met
with among barbaric tribes. Thus it has lately been pointed out that the
system of lucky and unlucky days, which led tlie natives in Madagascar
to kill many infants as of inauspicious birth, is adojited from Arabic
magic, and it is to be expected that many other magical arts, if their
formulas are accurately described, may in like manner be traced to their
origin.
Society. — One of the most interesting features of savage and barbaric
life is the existence of an unwritten code of moral conduct, by which
fiimilies and tribes are practically held together. There may be no laws
4S2 HINTS TO TRAVET.LERS.
to punish ciime, and the local religion may no more concern itself
directly with men's behaviour to one another than it did in the South
Sea Islands. But among the roughest peojjle there is family affection,
and some degree of mutual help and trust, without which, indeed, it is
obvious that society would break up, perliaps in general slaughter. Con-
sidering the importance of this primitive mornlity in the history of man-
kind, it is unfortunate that the attention of travellers has been so little
drawn to it, that our information is most meagre as to how far family
affection nmoiig rude tribes may be taken to be instinctive, like that of
the lower animals, or how far morality is produced by public opinion
favouring such conduct as is for the public good, but blnming acts which
do harm to the tribe. It is desirable to inquire what conduct is sanctioned
by custom among any people, whether, for instance, infanticide is tho".ght
right or wrong, what freedom of behaviour is approved in youths and
girls, and so on. For though breaches of custom may not be actually
punishable, experience will soon convince any explorer among any rude
tribe that custom acts in regulating their life even more strictly than
among ourselves. The notion of even savages leading a free and un-
restrained life is contradicted by those who know them best ; in fact, tliey
are bound in every act by ancestral custom. While each tribe thus has
itf= moral standard of right and wrong, this differs much in different tribes,
and one must become intimately acquainted with any people to ascertain
what are really their ruling principles of life. Accounts have been often
given of the natural virtue and happiness of rude tribes, as in the forests
of Guiana or the hiUs of Bengal, where the simple native life is marked
by truthfulness, honesty, cheerfulness, and kindness, which contrast in
a striking way with the habits of low-class Europeans. There are few
phenomena in the world more instructive than morality tluis existing in
practical independence either of law or religion. It may still be pos-ilile to
observe it for a few years before it is altered by contact with civilisation,
which, whether it raises or lowers on the whole the native level, must
supersede in great measure this simple family morality.
The unit of social life is the family, and the family is based on a
marriage-law. Travellers who have not looked carefully into the social
rules of tribes they were describing, or whose experience has been of
tribes in a state of decay, have sometimes reported that marriage hardly
existed. But this state of things is not contirmed as descriptive of any
ANTHROPOLOGY. 433
healthj' human society, ho-wever rude ; in fact, the absence of definite
marriage ajDpears incompatible with the continued existence of a tribe.
Tlierefore statements of this kind made by former visitors should be
carefully sifted, and marriage-laws in general deserve careful study.
The explorer will hardly meet with marriage at so low a stage that the
union can be described as little beyond annual pairing ; but where
divorce is almost unrestricted, as in some African tribes, there is more
or less api^roach to this condition, which is possible, though ixnusual,
under such laws as that of Islam. Polygamy, which exists over a large
part of the globe, is. a well-understood system, but information is less
complete as to the reasons which have here and there led to its opposite,
polyandry, as among the Toda hill-tribes and the Nairs in South India.
Among customs deserving inquiry are match-making festivals at spring-
tide or harvest, when a great part of the years marriages are arranged.
This is not only often done among the lon-er races, but traces of it remain
in Greece, where the dances at Megara on Easter Tuesday are renowned
for wife- choosing, and till lately iu Brittany, where on Michaelmas Day
the girls sate in a row decked in all their finery on the bridge of Penze,
near Morlais. The custom of bride-capture, where the bridegroom and
his friends make show of carrying off the bride by violence, is known in
Europe as a relic of antiquity, as in ancient Kome, Wales within the last
century or two, or Tyrol at the present day ; but in more barbaric regions,
as on the Malay peninsula or among the Kalmuks of North Asia, it may
be often met with, practised as a ceremony, or even done in earnest. On
the other hand, restrictions on marriage between kinsfolk or clansfolk are
more prominent among the lower races than in the civilised world, but
their motive is even now imperfectly understood. Partly these restric-
tions take the form we are accustomed to of prohibiting marriage between
relatives more or less near in our sense, but among nations at a lower
level they are apt to involve also what is called exogamy or "marrying-
out." A tribe or people— for instance, the Kamilaroi of Australia, or the
Iroquois of North America— is divided into hereditary clans, members
of which may not marry in their own clan. In various parts of the
world these clans are named from some animal, plant, or other object,
and anthropologists often call such names " totems," this word being
taken from the native name among Algonquin tribes of North America.
For an instance of the working of this custom among the Iroquois tribes,
2 G
434 HINTS TO TRAVELLERS.
a Wolf was considered brotlier to a Wolf of any other tribe, and might
not marry a W^olf girl, who was considered as his sister, but he might
marry a Deer or a Heron. In contrast with such rules is the practice of
endogamy, or " marrying-in," as among the Arab tribes, who habitually
marry cousins. But it will be found that the two rules often go together,
as where a Hindu miist practically marry within his own caste, but at
the same time is prohilwted from marrying in his own gotra or clan.
Researches into totem-laws are apt to bring the traveller into contact
with other relics of the ancient social institutions in which the.se laws
are rooted, especially the practice of reckoning descent not on the fathei-'s
side, as with us, but on the mother's side, after the manner of the
Lycians, whose custom seemed extraordinary to the Greeks in the time
of Herodotus, but may be still seen in existence among native tribes of
America or in the Malay islands. Even the system of relationship
familiar to Europeans is far different from those of regions where forms
of the " classificatory system " prevail, in which father's brothers and
mother's sisters are called fathers and mothers. In inquiring into native
laws of marriage and descent, precautions must be taken to ensure
accuracy, and esi^ecially such ambiguous English words as " uncle " or
" cousin " should be kejjt clear of.
Another point on which travellers have great opportunity of seeing
with their own eyes the working of primitive society is the holding and
inheritance of property, especially land. Kotions derived from our
modern law of landlord and tenant give place in the traveller's mind to
older conceiDtions, among which individual property in land is hardly
found. In rude society it is very generally the tribe which owns a dis-
trict as common land, where all may hunt and pasture and cut fire-wood;
while, when a family have built a hut, and tilled a patch of laud round it,
this is held in common by the family while they live there, but falls back
into tribe-land if they cease to occupy it. This is further organised in
what are now often called " village communities," which may be seen in
operation io Russia and India, where the village fields are portioned out
among the villagers. Ttiose who have seen them can understand the
many traces in England of the former prevalence of this system in
" common fields," &c. There is the more practical interest in studying
the working of this old-world system from the light it throws on projects
of communistic division of land, which in such villages may be studied.
ANTHKOPOLOGY. 435
and its merits and defects balanced. On the one hand it assiu-es a main-
tenance for all, while on the other it limits the population of a district,
the more so from the obstinate resistance which the council of " old men "
who manage a village always oppose to any improved method of tillage.
Not less perfectly do the tenures existing in many countries show the
various stages of landholding which arise out of military conquest. The
absolute ownership of all the land by a barbaric chief or king, which
may be seen in such a country as Dahome, whose subjects hold their
lands on royal sufferance, is an extreme case. In the East, feudal tenures
of land granted for military service still have much the same results as
in medicBval Europe.
At low levels of civilisation the first dawning of criminal law may be
seen in the rule of vengeance or retaliation. The person aggrieved, or his
kinsfolk if he has been killed, are at once judges and executioners, and the
vengeance they inflict stands in some reasonable relation to the offence
committed. Not only is such vengeance the great means of keeping order
among such rude tribes as the Australians, but even among half-civilised
nations like Abyssinians and Afghans the primitive law may still be
studied in force, carried oiit in strict legal order as a lex talionis, not
degraded to mere illegal survival in outlying districts like the " vendetta "
of modern Europe, carried on even now, in spite of criminal jurisprudence,
which for ages has striven to transfer punishment from jn-ivate hands to
the State. Whether among .savages, barbarians, or the lower civilised
nations, the traveller will find everywhere matter of interesting observa-
tion in the law and its administration. The law may be still in tlie state
of unwritten custom, and the senate or council of old men may be the
judges, or the power at once of lawgiver and judge may have passed into
the hands of the chief, who, as among the modern Kafirs, may make a
handsome revenue by the cattle given him as fees by both sides, a fact
interesting as illustrating the times when an European judge took gifts as
a matter of course. Among the nations at higher levels of culture in the
East, for instance, most of the stages may still be seen through which the
administration of law, criminal and civil, was given over to a trained
legal class. One important stage in history is marked by religion taking
to itself legal control over the conduct of a nation. The working of
this is seen among Oriental nations, whether Mohammedan, Brahman
or Buddhist, whose codes of law are of an ecclesiastical type, and the
2 G 2
436 HINTS TO TKAVELLERS.
lawyers theologians. There is much to he learnt from the manner
in which such law is administered, and the devices are interesting
by which codes framed under past conditions of society are practically
accommodated to a new order of things, without professedly violating
laws held to be sacred, and therefore unchangeable. Ordeals, which have
now disappeared from legal procedure among European nations, are
often to be met with elsewhere. Thus in Arabia the ordeal by touching
or licking hot iron is still known (the latter is an easy and harmless
trick, if the iron is quite white-hot). In Burma, under native rule, the
ancient trial of witches by " swimming " went on till lately. In many
countries also symbolic oaths invoking evils on the perjurer are to be
met with, as when the Ostyaks in Siberia swear in court by laying their
hand on a bears head, meaning that a bear will kill them if they lie. It
shows the carelessness with which Europeans are apt to regard the
customs of other nations, that in English courts a Chinese is called upon
to swear by breaking a saucer, under the entirely erroneous belief that
this symbolic curse is a Chinese judicial oath.
The most undeveloped forms of government are only to be met with in
a few outlying regions, as among some of the lower Esquimaux or Eocky
Mountain tribes, where life goes on with hardly any rule beyond such
control as the strong man may have over his own household. Much
oftener travellers have opportunity of studying, in a more or less crude
state, the types of government which prevail in higher culture. It is of
e&pecial interest to see men of the whole tribe gathered in assembly (the
primitive agora) to decide some qiiestion of war or migration. Kot less
instructive are the proceedings of the council of old men (the primitive
senidi^, who, among American tribes or the hill tribes of India, transact
the business of the tribe ; they are represented at a later social stage by
the village-elders of the Hindus or the Eussians. Among the problems
which present themselves among nations below the civilised level is that
of the working of the patriarchal system, still prevailing among such tribes
as the Bedaween, while often the balance of power is seen adjusting itself
between the i^atriarchal heads of families and the leaders who obtain
authority by success in war. The struggle between the hereditary chief
or king and the military despot, who not only usurps his place but seeks
to establish hereditary monarchy in his own line, is one met with from
low to high levels of national life. The traveller's attention may be
AJSTHROPOLOGY. 437
called to the social forces whicli do their work independently oi" men in
authority, and make society possible, even when there is little visible
authority at all. The machinery of government described in books is
often much less really powerful than public opinion, which controls
men's conduct in ways which are so much less conspicuous that they
have hardly yet been investigated with the care they deserve.
Beligion and Mythology. — While great religions, like Mohammedanism
and Buddhism, have been so carefully examined that European students
often know more about their sacred books than the believers themselves,
yet the general investigation of the religions of the world is very im-
perfect, and every effort should be made to save the details from being
lost as one tribe after another disappears, or passes into a new belief.
Missionaries have done much in recording particulars of native religions,
and some have had the skill to describe them scientifically; but the point
of view of the missionary engaged in conversion to another faith is un-
favourable for seeing the reasons of the beliefs and practices he is striving
to upset. The object of the anthropologist is neither to attack nor defend
the doctrines of the religion he is examining, but to trace their rational
origin and development. It is not only among the rudest tribes that
religious ideas which seem of a primitive order may be met with, but
these hold their place also among the higlier nations who profess a
"book-religion." Thus the English or German peasant retains many
ideas belonging to the ancestral religion of Thor and Woden, and the
modern Burmese, though a Buddhist, carries on much of the old worship
of the spirits of the house and the forest, which belong to a far earlier
religious stratum than Buddhism. It is in many districts possible for
the traveller to obtain at first hand interesting information as to the
philosophical ideas which underlie all religions. All over the world,
people may be met with whose conception of soul or spirit is that belong-
ing to primitive animism, namely, that the life or soul of men, beasts, or
things, resides in the phantoms of them seen in dreams and visions.
Quite lately, a traveller in British Guiana had serious trouble with one of
his Arawaks, who, having dreamt that another had spoken impudently
to him, on waking up went quite naturally to his master to get the
offender punished. So it is reported that our officials in Buiina have
considered themselves disrespectfully treated when the wife or servant
of the person they have come to see has refused to wake him, the
438 HINTS TO TRAVELLERS.
Englislimau uot understanding that these people hold early animistic
ideas, believing the soul to be away from the sleeper's body in a dream,
so that it might not find its way back if he were disturbed. As scientific
ideas of the nature of life and dreams are rapidly destroying these primi-
tive conceptions, it is desirable to collect all information about them for
its important bearing on the history of philosophy and religion. The
same m;iy be said as to the ancient theory of diseases as caused by
demons, and the cx^Dulsion and exorcism of them as a means of cure,
which may still be studied everywhere outside the scientific nations. In-
formation as to religious rites is of course valuable, even when the foreign
observer does not understand them, but if possible their exact meaning
should be made out by some one acquainted with the language, other-
wise acts may be confused which have really different senses, as where a
morsel of food offered as a pious offering to an ancestral ghost may be
taken for a sacrifice to appease an angry wood-demon. A people's idea
as to the meaning of their own rites may often be very wrong, but it is
always worth while to hear what they think of the purpose of their
prayers, sacrifices, purifications, fasts, feasts, and other religious ordi-
nances, which even among savage tribes have been long since stereotyped
into traditional systems.
Mythology is intimately mixed uj) with religion, which not only ascribes
the events of the world to the action of spirits, demons, or gods, but
everywhere individualises many of these beings under i")ersonal names,
and receives as sacred tradition wonder-tales about them. Thus, to
understand the religion of some tribes, we have not only to consider the
rude philosophy under which such objects as heaven and eartli or sun and
moon- are regarded as personal beings, whose souls (so to sjieak) are the
heaven-god and earth-god, the sun-god and moon-god ; but we have to go
on further and collect the religious myths which have grown on to these
superhuman beings. The tales which such a peoj^le tell of their origin
and past history may to some extent include traditions of real events,
but mostly they consist of myths, which are also worth collecting, as they
often on examination disclose their origin, or part of it. This is seen, for
instance, in the South Sea Island tale of the god Maui, whose death, when
he plunged into the body of his great ancestress the Night, is an obvious
myth of the sunset. The best advice as to native mythology is to write
down all promising native stories, leaving it to futui-e examination to
ANTHROPOLOGY. 43D
decide wliicli are worth publishing. The native names of personages
occ^^rring in such stories should be inquired into, as they sometimes carry
in themselves the exj^lanation of the story itself, like the name of Great^
Woman-Night in the Polynesian myth just referred to. Eiddles are some-
times interesting, as being myths with an explanation attached, like the
Greek riddle of the twelve black and twelve white horses that draw the
chariot of the day. It is not too much to say that everything which a
peoj^le thinks worth remembering as a popular tradition, and all the more
if it is fixed in rhyme or verse, is worth notice, as likely to contain some-
thing of historical value. That it may not be historically true is beside the
question, for the j)oetic fictions of a tribe often throw more light on their
history than their recollections of petty chiefs who quarrelled fifty years
ago. The myths may record some old custom or keep up some old word
that has died out of ordinary talk, or the very fact of their containing a
story known elsewhere in the world may give a clue to forgotten inter-
course by which it was learnt.
Customs. — It remains to say a few words as to the multifarious customs
which will come under the traveller's observation. It does not follow
that because these may be mentioned or described in books they need not
be further looked into. The fact is that accurate examination in such
matters is so new, that something always remains to be made out
especially as the motives of so many customs are still obscure. The
practice of artificially deforming the infant's skull into a desired shape,
which is not quite forgotten even in Europe, may be noticed with respect
to the question whether the form to which the child's head is bulged or
flattened is the exaggeration of the natural form of an admired caste or
race. If not, what can, for instance, have induced two British Columbian
tribes, one to flatten their foreheads and the other to mould them up to a
peak ■? In tattooing, an even more widespread practice, it is well to ascer-
tain whether the pattern on the skin seems to have been originally tribe-
marks or other signs or records, or whether the purpose is ornament. In
South-east Asia the two motives are present at once, when a man has
ornamental designs and magical charm-figures together on his body. With
regard to ornaments and costumes, the keeping-up of ancient patterns for
ceremonial jDurposes often affords curious historical hints. Thus in the
Eastern Archipelago, the old-fashioned garments of bark-cloth are used
in mourning by people who have long discarded them in ordinary wear,
440 HINTS TO TRAVELLEKS.
and another case is found among some natives of South India, whose
women, though they no longer put on an apron of leaves as their real
ordinary garment, wear it over a cotton skirt on festival-days. Among
the amusements of a peoi:)lc, songs are often interesting musically, and
it is well to take them down, not only for the tunes but also for the
words, which sometimes throw light on old traditions and beliefs.
Dancing varies from spontaneous expression of emotion to complex
figures handed down by tradition and forming part of social and re-
ligious ceremony. The numl)er of popular games in the world is smaller
than would be supposed. When really attractive they may be adopted
from one people to another till they make their way round the world.
Any special variety, as of ball or draughts, should therefore be noticed,
as it may furnish evidence of intercourse by which it may have come
from some distant nation.
Though the subjects of anthropological interest are not even fully
enumerated in the present chapter, some idea may have been given of the
field of observation still open to travellers, not only in remote countries,
but even in Europe. In taking notes, the explorer may be recommended
not to be afraid of tedious minuteness, whereas the lively superficiality of
pojjular books of travel makes them almost worthless for anthropology.*
QuEBiES ON Antheopology.— 5// A. W. Franks, c.b., f.r.s.
Keej)er of British and Mediseval Antiquities and Ethnography, British
Museum.
I. Physical Character.
Average height of men and women in each tribe.
Woolliness of hair.
Prognathism.
Strength in lifting and carrying weights, &c.
* More extended accounts of the departments of the Science of Man here
noticed, and a list of works useful to advanced students, will be found in Tyler's
' Anthropology : an Introduction to the Study of Man and Civilisation '
(Macmillau and Co., 2ud ed., 1889). [Editors.]
QUERIES ON ANTHROPOLOGY. 441
Speed in nmniDg.
Accuracy of aim.
Knowledge of numbers, weights, and measures.
II. Mode of Suhsistence.
Whether mainly by hunting, or by pastoral or agricultural pursuits.
Any instances of dwellings in caves.
Use of boats ; forms of boats and of paddles ; mode of paddling.
Any particular stratagems used in hunting, snares and traps ; imple-
ments for hunting ; use of dogs and of cross-bows, as well as bows and
arrows.
Fishing: nets; tish-hooks; spears; any javelins or arrows with loose
heads attached by a cord.
Modes of cooking, and implements used; any particular observances
ill cooking or at meals; any separation of sexes at meals. How is fire
pro iuced ? and are any persons charged with the preservation of it ?
Forms and construction of houses. Separation of the sexes.
Furniture of houses.
Plans of towns and fortifications.
Plants cultivated for food or manufactures ; agricultural implements.
III. Reli(/io)i (tud Cuafoms.
What are the idols and their names ? Is there any distinction between
them in importance? What worship is paid to them? and what offerings
are made, and on what occasions?
Are there any particular superstitions ? What fetishes or amulets are
used ? by whom are tliey made ? Are tliere any forms of divination, any
use of casting lots with cowries, ordeals by poison or otherwise?
Cannibalism, and motives for tlie same.
Funeral rites. Belief in a future state. Deposit of objects with the
dead, and whether deposited broken or whole, in or on the graves.
IV- Arts and M<ini(factures.
Mode of spinning and weaving ; patterns and materials employed.
Dyeing and nature of dyes.
Any mode of preparing and working leather.
442 HINTS TO TRAVELLERS.
Any knowledge of glass-making. If not acquainted with the manufac-
ture of glass, do they melt down broken European glass and beads to make
armlets and other ornaments ?
Musical instruments: their forms, nature, and names.
Knowledge of jjottery and mode of manufacture.
Use and manufacture of tobacco and other narcotics; forms of tobacco-
pipes: any ceremonies connected with smoking; use of snuff; snuff-
bottles.
Manufacture and trade in salt, wine, beer, or other liquors.
Knowledge of simples and medical remedies, cupping, &c.
Ivory and wood-carving.
Metallurgy : working in the various metals, whether by a special class
of people or tribes ; implements used in smelting, &c. Where are the
ores obtained ?
Is there any knowledge of precious stones ?
V. Personal Ornaments, Disfigurements, &c.
Are there any special marks made by tattooing or cicatrices to distin-
guish the various tribes ? are they the same in both sexes ? Drawings
of these marks would be very desirable, distinguishing each tribe.
Are the teeth filed or knocked out ? If the former, into what shapes
are they tiled ? when is the filing effected ? and is it the same for both
sexes ?
Is antimony used for the eyelids ? and how is it applied ?
Are ear -ornaments worn by either sex ? are they pendent or inserted in
the lobe ? Are there any nose or lip ornaments ?
Is the hair cut into any peculiar shape, or is its colour altered by
dyeing ?
Is any cap or protection worn on the penis, as by the Kafirs and other
tribes ?
Any peculiarities of dress for men and women ? any distinction between
married and unmarried ?
What protection is worn in battle ? What are the forms of the weapons ?
and is any missile weapon in use ?
Are any marks used as distinctions for bravery, success in hunting
or rank ?
ETHNOLOGICAL QUESTIONS. 443
VI. Ivory and Wood Carving.
If elephant ivory is not of native origin, where is it obtained ? Are
any other materials of the same nature employed in carving, such as
walrus-tusk, cachalot teeth, &c. ? Are any very hard woods employed ;
and if so, how are they worked ?
VII. Money.
What kinds of money are in use ? Do the coins pass by weight as
bullion, or have they a recognised value ? Are any objects such as iron
bars or tools, salt, pieces of cotton, cowries, beads, wampum, &c., em-
ployed as a means of exchange ? If so employed, is there any recognised
way in which their value is certified, or is their value the subject of
bargain in each case ?
VIII. MisceUaneous.
Any knowledge of the stars and constellations ?
What games are in use ? and liow are they played ?
Are any ancient stone implements found among the natives ? and have
they any superstitious regard for them ?
Are any peculiar ornaments lased in dancing ?
Are there any modes of marking property ?
Are wooden pillows in use? and do their forms differ according to
tribes ?
It may be added that the native names will in all cases be very de-
sirable.
Ethnological Questions. — By J. G. Feazer.
{Supplementary to those o/Mr. Tyloe and Mr. Franks.)
1. Are the tribes, clans, or families named after common objects, as
animals or plants? Note down all such names. Have the tribes, clan?,
&c., any special beliefs or superstitions regarding the things whose names
they bear? e/j., if they are named after an animal, may they eat this
animal ? May person.s of the same name marry or have sexual connection
444 HINTS TO TRAVELLERS.
witli each other? if not, wliy not? Note all cases of forbidden foods,
with tlie reasons assigned for the prohibitions.
2. Any ceremonies before the setting out or after the return of a
hiinting, fishing, or war party? Do the hunters, fishers, or warriors
perform any ceremonies, or observe any special rules as to diet, sleeping,
using certain words, &c., while they are hunting, &c. ? Are the persons left
at home boimd to observe any sjiecial rules during the absence of the
hunters, fishers, or warriors? Is a man who has killed an enemy or
any large game obliged to jDcrform certain ceremonies, or to observe a
special regimen for a time? Are men obliged to abstain from women
at these times (war, hunting, &c.), or at any other times ? if so, why ?
3. Any superstitious observances at cutting down trees, building
houses, clearing laud for cultivation, turning up the soil (by hoeing or
]iloughing), sowing, ripening of the crops, and harvest? Any rules as
to eating the new corn, rice, yams, &c. ? Any ceremonies for the making
of rain or of fine weather ? If land is held in common, how is the
produce distributed ?
4. Any system of taboo? Who can impose a taboo? and for what
inirposes? Is it used to protect property? "What is the effect of
breaking a taboo ?
5. Any periodic festivals, as at the solstices, equinoxes, or New Year ?
Is the beginning of the New Year determined by any agricultural season,
as harvest or sowing ? Any period of general licence and lawlessness at
the New Year, or at any other time? Any periodical expulsion of evil
(ghosts, demons, &c.)? any general atonement or purification of the
district or village at certain times, as the New Year ? Anything in the
nature of a scapegoat (human or animal) at the New Y^'ear, or any other
time ? Any periodic extinction of fire and solemn kindling of a new or
sacred fire ? Is the fire formally extinguished on other occasions, as after
a death, during a drought, &c. ? Is it kept as a rule perpetually burning,
and is its accidental extinction unlucky ?
6. Has each jierson a guardian spirit, patron object, or fetish (animal,
plant, stone, &c.), with which he believes that his life is bound up ?
How is such a guardian spirit or fetish acquired? How is it treated
in ordinary life and on special occasions, as sickness, war, &c. "What is
the exact relation between it and the man ? and between it and the totem
(sacred animal, plant, &c.) of the tribe or clan ?
HINTS ON ANTHROPOLOGY. 445
7. Are kings and chiefs supposed to be endowed with supernatural
powers, as the power of making rain and sunshine, causing the crops to
grow, &c. ? Are they put to death for failing to exert the§e powers, or
for any other reason ? Have they to observe any peculiar rules of life?
Hints on Anthropology. — By H. H. Johnston.
I DO not know that I can add any observations of interest to the
admirable resume of the study of anthropology contributed by
Mr. E. B. Tylor to this manual, but I may offer a few practical
suggestions to travellers intending to visit savage countries which may
be of use to them, and which arc based on my own practical experience
of the difficulty in dealing with the untutored savage.
Tliere is no more fascinating study than the psychology and physical
condition of races which belong to other varieties of man than our own ;
with differences in mental and bodily constitution which, but for their
variability, would be almost specific in character. Indeed, were it not
that there are so many gradations between the Aiab and Negro, or
the Dravidian and Australian, judged by our fashion of dealing with
other mammalian forms, the Negro or Australian (but that their con-
necting links with the white men and the yellow are still existing) would
be as much or more entitled to be constituted separate species of the
genus Homo as the chimpanzee, the bald ape, and the gorilla are
reckoned as distinct and different si^ecies of the genus Anthropopitheciis.
Consequently, while the ediicated man of science finds his mind broadened
and refreshed by contemplating other races whose schemes of morality
and social economy are based on widely different premises to his own, and
whose physical organisation is, in common with the race's j^sychological
condition, often admirably adapted to the nature of their surroundings and
the exigencies of their mode of life, while he will study without prejudice
the different phases of humanity in the different quarters of the globe with
the same dispassionate interest with which he would regard the forms of
life evolved under totally different conditions in another planetary body, the
inexjoerienced European is too apt to approach the study of anthropology
full of the prejudices with which his Eurojican mode of thought has been
446 HINTS TO TRAVELLERS.
surrounded. He forgets that tlie duty of an ol)server is to collect facts
without bias, and not to give xis his own partial opinion of them. And
because these practices are inconvenient or inexijedient in our own
civilised condition of existence, that is no reason why he should neglect
to describe them, or qualify them as "nasty," "indecent," horrible,"
" absurd," or " wicked," when he encounters them among the tenets of
alien races. He should remember that to the scientific mind nothing is
common or unclean, nor is one organ less decent than another. It is
the duty of every civilised traveller in countries newly opened up to
research, to collect facts, plain unvarnished facts, for the information of
those leading minds of the age who, by dint of great experience, can ably
generalise from the details contributed from diverse sources.
Europeans, who are among the first to penetrate little known, little ex-
ploited lands, inhabited by races totally differing from our o-«-n, have often
failed to rightly exercise the great privilege which fate has conferred on
them, by not securing a i^recise knowledge of the strange peojile with whom
they come into contact for the first time. Facts gathered under these
conditions may be invaluable and irreplaceable. But under all conditions
of examining into the characteristics of an alien race of men, the traveller
should present himself before them with a perfectly ojDen mind. He
should not seal up the timid confidence of the savage, and check —
perhaps fatally — the outpouring of what might be of the greatest interest
to the scientific student of humanity, by deriding or condemning such
and such a custom, according as it may appear ridiculous or reprehensible
to his own i:)rejudiced views ; nor need he unnecessarily ofi"end the natives
by informing them that they are ape-like, or indecently naked, or pre-
posterously clothed, or endowed with an offensive odour. He should
remember that he himself may appear to them equally hideous, and
may resemble a devil in their eyes, just as they resemble apes in his;
that they think his clothing iinnatural and imhealthy, when they
themselves can live so comfortably and cleanly, with nothing to cover
their own glossy, well-oiled skins, and he ought to be able to recognise
that the peculiar smell proceeding from his own body which, to his own
olfactory sense, does not exist, is painfully unpleasant in their savage
nostrils.
In collecting facts about anthropology, whatever you do, avoid vague-
ness. It is better to describe one custom, one style of architecture, one
HINTS ON ANTHROPOLOGY. 447
individual's body, one religious ceremony -with minuteness, even to the
neglect of everything else (from the want of time), than to lay before us
on your return a series of vague general remarks that the scientific anthro-
pologist will toss aside in disdain. Where you can obtain precise body
measurements, as according to the rules laid down in the various manuals
of anthropology, such will prove of the greatest interest and value.
Always photograph, if you can, in preference to drawing. A really
careful drawing is of course as good as a photograph, but it will not be
received by scientific men with the same amount of trust in its authen-
ticity as a photograph ; moreover, to make a study of a man's face or
body that shall be as correct as a photograph, you must have had a
preliminary education in drawing, which few explorers have ever had
the leisure to undergo. Still, where it is impossible to use photography
or accurate anthropometric instruments, rough sketches or measure-
ments are not to be despised. They will, at any rate, serve to give some
idea of the race you have encountered. You will probably find tliat
savage races have the very strongest objection to be measured, and in
such cases it is better to abandon the idea altogether until you have
resided long amongst them. The same remark applies to both painting
and photography. All these practices must be gradually introduced to
the native mind, and not sprung upon it with alarming abruptness.
If possilile, your photographs of groups and individuals should betaken
instantaneously, and without deliberate posing, which will never represent
your subjects in their natural aspect. You should watch your oppor-
tunity with some one of the many handy little pocket-cameras now in
vogue, and photograph the natives in their most characteristic attitudes
and engaged in their customary occuixations. As in literary descriptions,
so in artistic representation, always avoid generalisation as much as
possible, and make careful minute studies of individuals rather than of
groups and assemblages of people. Endeavour to get into conversation
with the natives as much as possible, either directly, or throiigh inter-
preters. Encourage them to talk on any subject that interests them, and
write down phonetically words and phrases that fall from their mouths.
Savages often speak with much more clearness, slowness, and distinctness
than we do, and you will find it not very difficult, when you are used to
phonetic writing, to report whole conversations pretty much as they are
uttered. When you translate these afterwards, with the help of your
448 HINTS TO TRAVELLERS.
interpreter, mauy curious facts and oxpressious and ideas will be brought
to light which you probably would not have elicited by direct questioning.
At the same time, question the natives when they are in a communicative
mood. Enquire into all the details of their lives. Take care, as I have
said before, not to repel them by any expression of your own opinion of
certain facts they may reveal, and you will collect a series of most valuable
memoranda on the condition of the uncivilised mind. Endeavour to
make your notes like your pictures and photographs. Write down things
of interest as you hear them or see them, and do not trust more than you
can help to the deceptive gloss of memory.
With regard to languages, where there is not time to make a profound
study of the forms of sjieech spoken around you, you may nevertheless
collect in a short time data very valuable to philologists. Tho.se who
intend to collect vocabularies in the districts they travel through (and
all who explore new countries should endeavour to do so), should have
these vocabularies printed in pamphlets, with six other blank columns on
the page, besides the column of English words, so that among related
languages the vocabulary will have a comparative character (words for
the same subject being placed side by side) that will enable the student
to ascertain the relative degree of relationship between the different
dialects at a glance. In compiling the vocabularies, the student should
be exceedingly careful as to orthography, and not perpetrate the
monstrosities in spelling of which English explorers, down to a quite
recent date, have been guilty.
Statistics of Strength, Stature, etc. — Bi/ Fraxcis Galton, f.r.s.
It is not in the power of a traveller to measure a large number of half-
savage natives individually, but it is well within his power to obtain
approximate and valuable statistics concerning their stature, strength,
keenness of eyesight, speed, accuracy of aim, and much else, by a very
simple process. It enables him to calculate with a degree of precision (that
only those who are familiar with such experiences would easily credit),
not only the usual averages, but also the proportion of the people whose
strength, stature, &c., exceeds any value that may be mentioned. The
STATISTICS OF STRENGTH, STATURE, ETC. 449
observations consists of two (or better of three) " pass-tests." The calcu-
lations are made by the aid of the subjoined Table I.
The simplest way of explaining the method is to work out an
example. Let us suppose that the traveller wishes to ascertain the
strength of the race of people he is among, as estimated by the weights
that different members of it are able to lift. For this purpose, he must
select two (or better, three) heavy objects, such as packages or stones, of
such weights that only a few of the natives will fail to hft the one, while
many of them will fail to lift the other. He must ascertain the exact
weights of these packages at his leisure, either before or after the experi-
ment. Call their weights respectively A and B. Then let him induce
adult male natives in crowds to try their strength upon them. He may,
to this end, good-humouredly, but discreetly, taunt them with accusations
of weakness, and offer small prizes to the strongest. He has lastly to
note (1) the number of the men who were submitted to the experiment,
(2) the number of those who failed to lift A, and (3) the number of
those who failed to lift B. This completes the observations. He must
then reduce these figures to percentages, viz., out of every 100 persons n
fail to lift A and m fail to lift B.
All the required results can be deduced from these data by the help
of Table I., according to the method summarised in Tables II. and
III., and exj^lained more fully as follows : —
The data in the first of the examples in Table II., are that 30 per cent.
(n) of the natives fail to lift 68 lbs. (A), and that 60 per cent. (?n) fail to
lift 77 lbs. (B). Call these percentages of w = 30 and 7n=60 by the name
of " grades 30'^ and 60° " (the reason for doing so is explained in the note
at the end of the last paragraph, p. 453). Then look in Table I. for the values
a and h corresponding to the grades 30° and 60° respectively ; they are a =
-078 and 6= +0-38. We have next to find the value of B-A divided
by h—a. To obtain B — A, we subtract 68 from 77, which gives 9 lbs. ;
to obtain h-a, we add + 0"78 to + 0-38, which gives 1-16, because the
subtraction of — 0'78 is the same thing as the addition of -f- 0'78.
Then dividing B — A by 6 — or,, that is 9 lbs. by 1-16, we obtain 7*8 lbs.
This determines the value of Q, which measures the varia^'Uity in strength
among the supposed natives, and it enables us to calculate how much the
strengths of the men who occupy tlie various grades, or class places,
exceed or fall short of the median strength of all of them. (The median, M,
2 H
450 HINTS TO TRAVELLERS.
is i>ractically the same as the average, and will he here treated as such.)
To do so, we, in any desired case, multiply the tabular values in Table I.
by Q. Thus the tabular value corresponding to grade 4'' lieing — 2'60, it
follows that the inferiority in lifting power of the men who occupy
that grade, below the average power, is— 2'GO x G IIjs. = 15'6 Hjs. Lastly,
we are able by working backwards, to calculate the average strength of
all the men ; thus finding, as is shown in Table III., that the strength of
the man at grade 30° is Qxa = 7'8x7"8 = 6'l lbs. (or say 6 lbs.) below
the average of all the people, and knowing that the actual strength of
that man is 68 lbs., it follows that the average strength of all the men
is C8 + 6 = 74 lbs. Again, as the strength of the man at grade 60°
is Q X Z) = 7"8 X 3'8 = 3 lbs. above the average, and knowing that his
actual strength is 77 lbs., it follows that the average strength of all the
people is 77 — 3 = 74 lbs. as before.
The second example refers to stature ; it is treated in exactly the same
way as the first. In the third examj^le of weight, three test values have
been used. A, B, and C, and the values of Q and M are calculated
independently from the data of A and B, of A and C, and of B and C
respectively. It will be observed how nearly these three pairs of results
agree together, and that the three determinations of M are identical.
The data used in these examples are not fancifully invented for the
purpose, but are selected at hazard from a classified set of actual
measurements. The results obtained from them by the heljD of Table I.
are seen to be almost identical with those that had been arrived at
by the laborious measurements of very many individuals, after per-
forming the usual and somew-hat tedious arithmetic o2)erations. I ought
however, to say that the figures given in the examples as referring
to strength of lifting, in reality referred to strength of pull with the arm
as in drawing a bow, but they serve equally well as an example of the
method of working. I had no observations of lifting weights available.
Numerous other topics are suitable for inquiry by this method ; among
them are —
Keenness of eyesight — by distinguishing objects at different measured
distances. The experiment should be made in a full, but not dazzling,
