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find means of transport, the omitted figures must be supplied in the
following schedule, the others must be corrected where required, and the
whole must be added together.
Stores for general use:--
Various small stores 95 lbs.
Various heavy stores
Stationery 30
Mapping 31
Natural History (occasional) 30
Stores for Individual use:--
For each white man (at rate of 7 lbs. per month) 66
For each black man (at rate of 3 lbs. per month 30
Presents and articles of payment are usually of far
greater weight than all the above things put together.
TOTAL WEIGHT TO BE CARRIED BY EXPEDITION 282
Mem.--If meat and bread, and the like, have to be carried, a very large
addition of weight must be made to this list, for the weight of a daily
ration varies from 3 lbs., or even 4 lbs., to 2 lbs., according to the
concentration of nutriment in the food that is used. Slaughter animals
carry themselves; but the cattle-watchers swell the list of those who
have to be fed.
Means of Transport.--In order to transport the articles belonging to an
expedition across a wild and unknown country, we may estimate as
follows:--
Beasts of burthen:--
An ass will not usually care more than about (net weight) 65 lbs.
A small mule 90
A horse 100
An ox of an average greed 120
A camel (which rarely can be used by an explorer) 300
It is very inconvenient to take more than six pack-animals in a caravan
that has to pass over broken country, for so much time is lost by the
whole party in re-adjusting the packs of each member of it, whenever one
gets loose, that its progress is seriously retarded.
Carriages.--An animal--camels always excepted--draws upon wheels in a
wild country about two and a half times the weight he can carry.
lbs.
A light cart, exclusive of the driver, should not carry
more than..................................................800
A light waggon, such as one or two horses would trot
away with, along a turnpike road, not more than...........1500
A waggon of the strongest construction, not more than.........3000
Weight of Rations.--A fair estimate in commissariat matters is as follows:--
A strong waggon full of food carries 1000 full-day rations
The pack of an ox " 40 "
The pack of a horse " 30 "
A slaughter ox yields, as fresh meat 80 "
A fat sheep yields " 10 "
(N.B. Meat when jerked loses about one-half of its nourishing powers.)
MEDICINE.
General Remarks.--Travellers are apt to expect too much from their
medicines, and to think that savages will hail them as demigods wherever
they go. But their patients are generally cripples who want to be made
whole in a moment, and other suchlike impracticable cases. Powerful
emetics, purgatives, and eyewashes are the most popular physickings.
The traveller who is sick away from help, may console himself with the
proverb, that "though there is a great difference between a good
physician and a bad one, there is very little between a good one and none
at all."
Drugs and Instruments.--Outfit of Medicines,--A traveller, unless he be a
professed physician, has no object in taking a large assortment of drugs.
He wants a few powders, ready prepared; which a physician, who knows the
diseases of the country in which he is about to travel, will prescribe
for him. Those in general use are as follows:--
1. Emetic, mild; 2. ditto, very powerful, for poison (sulphate of zinc,
also used as an eye-wash in Ophthalmia). e. Aperient, mild; 4. ditto,
powerful. 5. Cordial for diarrhoea. 6. Quinine for ague. 7. Sudorific
(Dover's powder). 8. Chlorodyne. 9. Camphor. 10. Carbolic acid.
In addition to these powders, the traveller will want Warburg's
fever-drops; glycerine or cold cream; mustard-paper for blistering;
heartburn lozenges; lint; a small roll of diachylon; lunar-caustic, in a
proper holder, to touch old sores with, and for snake-bites; a scalpel
and a blunt-pointed bistoury, with which to open abcesses (the blades of
these should be waxed, to keep them from rust); a good pair of forceps,
to pull out thorns; a couple of needles, to sew up gashes; waxed thread,
or better, silver wire. A mild effervescing aperient, like Moxon's is
very convenient. Seidlitz-powders are perhaps a little too strong for
frequent use in a tropical climate.
How to carry Medicines.--The medicines should be kept in zinc pill-boxes
with a few letters punched both on their tops and bottoms, to indicate
what they contain, as Emet., Astr. etc. It is more important that the
bottoms of the boxes should be labelled than their tops; because when two
of them have been opened at the same time, it often happens that the tops
run a risk of being changed.
It will save continual trouble with weights and scales, if the powders be
so diluted with flour, that one Measureful of each shall be a full
average dose for an adult; and if the measure to which they are adopted
be cylindrical, and of such a size as just to admit a common lead-pencil,
and of a determined length, it can at any time be replaced by twisting up
a paper cartridge. I would further suggest that the powders be
differently coloured, one colour being used for emetics and another for
aperients.
Lint, to make.--Scrape a piece of linen with a knife.
Ointment.--Simple cerate, which is spread on lint as a soothing plaister
for sores, consists of equal parts of oil and wax; but lard may be used
as a substitute for the wax.
Seidlitz-powders are not often to be procured in the form we are
accustomed to take them in, in England; so a recipe for making 12 sets of
them, is annexed:--1 1/2 oz. of Carbonate of Soda and 3 oz. of Tartarised
Soda, for the blue papers; 7 drachms of Tartaric Acid, for the white
papers.
Bush Remedies.--Emetics.--For want of proper physic, drink a charge of
gunpowder in a tumblerful of warm water of soap-suds, and tickle the
throat.
Vapour-baths are used in many countries, and the following plan, used in
Russia, is often the most convenient. Heat stones in the fire, and put
them on the ground in the middle of the cabin or tent; on these pour a
little water, and clouds of vapour are given off. In other parts of the
world branches are spread on hot wood-embers, and the patient is placed
upon these, wrapped in a large cloth; water is then sprinkled on the
embers, and the patient is soon covered with a cloud of vapour. The
traveller who is chilled or over-worked, and has a day of rest before
him, would do well to practise this simple and pleasant remedy.
Bleeding and Cupping'.--Physicians say, now-a-days that bleeding is
rarely, if ever, required; and that frequently it does much harm; but
they used to bleed for everything. Many savages know how to cup: they
commonly use a piece ofa horn as the cup, and they either suck at a hole
in the top of the horn, to produce the necessary vacuum, or they make a
blaze as we do, but with a wisp of grass.
Illnesses.--Fevers of all kinds, diarrhoea, and rheumatism, are the
plagues that most afflict travellers; ophthalmia often threatens them.
Change of air, from the flat country up into the hills, as soon as the
first violence of the illness is past, works wonders in hastening and
perfecting a cure.
Fever.--The number of travellers that have fallen victims to fever in
certain lands is terrible: it is a matter of serious consideration
whether any motives, short of imperious duty, justify a person in braving
a fever-stricken country. In the ill-fated Niger expedition, three
vessels were employed, of which the 'Albert' stayed the longest time in
the river, namely two months and two days. Her English crew consisted of
62 men; of these, 55 caught fever in the river, and 23 died. Of the
remaining seven, only two ultimately escaped scot-free; the others
suffering, more or less severely, on their return to England. In Dr.
McWilliams's Medical History of this expedition, it is laid down that the
Niger fever, which may be considered as a type of pestilential fever
generally, usually sets in sixteen days after exposure to the malaria;
and that one attack, instead of acclimatising the patient, seems to
render him all the more liable to a second. Every conceivable precaution
known in those days, had been taken to ensure the health of the crew of
the 'Albert.' A great discovery of modern days is the power of quinine to
keep off many types of fever. A person would, now, have little to fear in
taking a passage in a Niger steamer; supposing that vessels ran regularly
up that river. The quinine he would take, beginning at the coast, would
render him proof against fever, until he had passed the delta; but
nothing would remove the risk of a long sojourn in the delta itself.
However, I should add that Dr. Livingstone's experience on the zambesi
throws doubt on the power of quinine to keep off the type of fever that
prevails upon that river.
Precautions in unhealthy Places.--There are certain precautions which
should be borne in mind in unhealthy places, besides that which I have
just mentioned of regularly taking small doses of quinine, such as never
to encamp to the leeward of a marsh; to sleep close in between large
fires, with a handkerchief gathered round your face (natural instinct
will teach this); to avoid starting too early in the morning; and to
beware of unnecessary hunger, hardship, and exposure. It is a
widely-corroborated fact that the banks of a river and adjacent plains
are often less affected by malaria than the low hills that overlook them.
Diarrhoea.--With a bad diarrhoea, take nothing but broth, rice water, and
it may be rice, in very small quantities at a meal, until you are quite
restored. The least piece of bread or meat causes an immediate relapse.
Ophthalmia'.--Sulphate of zinc is invaluable as an eyewash: for
ophthalmia is a scourge in parts of North and South Africa, in Australia,
and in many other countries. The taste of the solution which should be
strongly astringent, is the best guide to its strength.
Tooth-ache.--Tough diet tries the teeth so severely, that a man about to
undergo it, should pay a visit to a dentist before he leaves England. An
unskilled traveller is very likely to make a bad job of a first attempt
at tooth-drawing. By constantly pushing and pulling an aching tooth, it
will in time loosen, and perhaps, after some weeks, come out.
Thirst.--Pour water over the clothes of the patient, and keep them
constantly wet; restrain his drinking, after the first few minutes, as
strictly as you can summon heart to do it. (See "Thirst" in the chapter
on "Water.") In less severe cases, drink water with a tea-spoon; it will
satisfy a parched palate as much as if you gulped it down in tumblerfuls,
and will disorder the digestion very considerably less.
Hunger.--Give two or three mouthfuls, every quarter of an hour, to a man
reduced to the last extremity by hunger; strong broth is the best food
for him.
Poisoning.--The first thing is to give a powerful emetic, that whatever
poison still remains unabsorbed in the stomach, may be thrown up. Use
soap-suds or gunpowder (see Emetics) if proper emetics are not at hand.
If there be violent pains and gripings, or retchings, give plenty of
water to make the vomitings more easy. Next, do your best to combat the
symptoms that are caused by the poison which was absorbed before the
emetic acted. Thus, if the man's feet are cold and numbed, put hot stones
against them, and wrap them up warmly. If he be drowsy, heavy, and
stupid, give brandy and strong coffee, and try to rouse him. There is
nothing more to be done, save to avoid doing mischief.
Fleas.--"Italian flea-powder," sold in the East, is really efficacious.
It is the powdered "Pire oti" (or flea-bane), mentioned in Curzon's
'Armenia' as growing in that country; it has since become an important
article of export. A correspondent writes to me, "I have often found a
light cotton or linen bag a great safeguard against the attacks of fleas.
I used to creep into it, draw the loop tight round my neck, and was thus
able to set legions of them at defiance."
Vermin on the Person.--I quote the following extract from Huc's 'Travels
in Tartary':--"We had now been travelling for nearly six weeks, and still
wore the same clothing we had assumed on our departure. The incessant
pricklings with which we were harassed, sufficiently indicated that our
attire was peopled with the filthy vermin to which the Chinese and
Tartars are familiarly accustomed; but which, with Europeans, are objects
of horror and disgust. Before quitting Tchagan-Kouren, we had bought in a
chemist's shop a few sapeks'-worth of mercury. We now made with it a
prompt and specific remedy against the lice. We had formerly got the
receipt from some Chinese; and, as it may be useful to others, we think
it right to describe it here. You take half an ounce of mercury, which
you mix with old tea-leaves previously reduced to paste by mastication.
to render this softer, you generally add saliva; water could not have the
same effect. You must afterwards bruise and stir it a while, so that the
mercury may be divided into little balls as fine as dust. (I presume the
blue pill is a pretty exact equivalent to this preparation.) You infuse
this composition into a string of cotton, loosely twisted, which you hang
round the neck; the lice are sure to bite at the bait, and they thereupon
as surely swell, become red, and die forthwith. In China and in Tartary
you have to renew this salutary necklace once a month."
Blistered Feet.--To prevent the feet from blistering, it is a good plan
to soap the inside of the stocking before setting out, making a thick
lather all over it. A raw egg broken into a boot, before putting it on,
greatly softens the leather: of course the boots should be well greased
when hard walking is anticipated. After some hours on the road, when the
feet are beginning to be chafed, take off the shoes, and change the
stockings; Putting what was the right stocking on the left foot, and the
left stocking on the right foot. Or, if one foot only hurts, take off the
boot and turn the stocking inside out. These were the plans adopted by
Captain Barclay. when a blister is formed, "rub the feet, on going to
bed, with spirits mixed with tallow dropped from a candle into the palm
of the hand; on the following morning no blister will exist. The spirits
seem to possess the healing power, the tallow serving only to keep the
skin soft and pliant. This is Captain Cochrane's advice, and the remedy
was used by him in his pedestrian tour." (Murray's Handbook of
Switzerland.') The recipe is an excellent one; pedestrians and teachers
of gymnastics all endorse it.
Rarefied Air, effects of.--On high plateaux or mountains new-comers must
expect to suffer. The symptoms are described by many South American
travellers; the attack of them is there, among other names, called the
puna. The disorder is sometimes fatal to stout plethoric people; oddly
enough, cats are unable to endure it: at villages 13,000 feet above the
sea, Dr. Tschudi says that they cannot live. Numerous trials have been
made with these unhappy feline barometers, and the creatures have been
found to die in frightful convulsions. The symptoms of the puna are
giddiness, dimness of sight and hearing, headache, fainting-fits, blood
from mouth, eyes, nose, lips, and a feeling like sea-sickness. Nothing
but time cures it. It begins to be felt severely at from 12,000 to 13,000
feet above the sea. M. Hermann Schlagintweit, who has had a great deal of
mountain experience in the Alps and in the Himalayas, up to the height of
20,000 feet or more, tells me that he found the headache, etc., come on
when there was a breeze, far more than at any other time. His whole party
would awake at the same moment, and begin to complain of the symptoms,
immediately on the commencement of a breeze. The symptoms of overwork are
not wholly unlike those of the puna, and many young travellers who have
felt the first, have ascribed them to the second.
Scurvy has attacked travellers even in Australia; and I have myself felt
symptoms of it in Africa, when living wholly on meat. Any vegetable diet
cures it: lime-juice, treacle, raw potatoes, and acid fruits are
especially efficacious. Dr. Kane insists on the value of entirely raw
meat as a certain anti-scorbutic: this is generally used by the
Esquimaux.
Haemorrhage from a Wound.--When the blood does not pour or trickle in a
steady stream from a deep wound, but jets forth in pulses, and is of a
bright red colour, all the bandages in the world will not stop it. It is
an artery that is wounded; and, unless there be some one accessible, who
knows how to take it up and tie it, I suppose that the method of our
fore-fathers is the only one that can be used as you would for a
snake-bite (see next paragraph); or else to pour boiling grease into the
wound. This is, of course, a barbarous treatment, and its success is
uncertain, as the cauterised artery may break out afresh; still, life is
in question, and it is the only hope of saving it. After the cautery, the
wounded limb should be kept perfectly still, well raised, and cool, until
the wound is nearly healed. A tourniquet, which will stop the blood for a
time, is made by tying a strong thong, string, or handkerchief firmly
above the part, putting a stick through, and screwing it tight. If you
know whereabouts the artery lies, which is the object to compress, put a
stone over the place under the handkerchief. The main arteries follow
pretty much the direction of the inner seams of the sleeves and trousers.
Snake-bites.--Tie a string tight above the part, suck the wound, and
caustic it as soon as you can. Or, for want of caustic, explode gunpowder
in the wound; of else do what Mr. Mansfield Parkyns well suggests, i.e.,
cut away with a knife, and afterwards burn out with the end of your iron
ramrod, heated as near a white heat as you can readily get it. The
arteries lie deep, and as much flesh may, without much danger, be cut or
burnt into, as the fingers can pinch up. The next step is to use the
utmost energy, and even cruelty, to prevent the patient's giving way to
that lethargy and drowsiness which is the usual effect of snake-poison,
and too often ends in death.
Wasp and Scorpion-stings.--the Oil scraped out of a tobacco-pipe is a
good application; should the scorpion be large, his sting must be treated
like a snake-bite.
Broken Bones.--It is extremely improbable that a man should die, in
consequence of a broken leg or arm, if the skin be uninjured' but, if the
broken end forces its way through the flesh, the injury is a very serious
one. Abscesses form, the parts mortify, and the severest consequences
often follow. Hence, when a man breaks a bone, do not convert a simple
injury into a severe one, by carrying him carelessly. If possible, move
the encampment to the injured man, and not vice versa. Mr. Druitt
says:--"When a man has broken his leg, lay him on the other side, put the
broken limb exactly on the sound one, with a little straw between, and
tie the two legs together with handkerchiefs. Thus the two legs will move
as one, and the broken bone will not hurt the flesh so much, nor yet come
through the skin."
Drowning.--A half-drowned man must be put to bed in dry, heated clothes,
hot stones, etc., placed against his feet, and his head must be raised
moderately. Human warmth is excellent, such as that of two big men made
to lie close up against him, one on each side. All rough treatment is not
only ridiculous but full of harm; such as the fashion--which still exists
in some places--of hanging up the body by the feet, that the swallowed
water may drain out of the mouth.
I reprint here the instructions circulated by Dr. Marshall Hall:--
"1. Treat the patient instantly, on the spot, in the open air, exposing
the face and chest to the breeze (except in severe weather).
"To Clear the Throat--2. Place the patient gently on the face, with one
wrist under the forehead; all fluids and the tongue itself then fall
forwards, leaving the entrance into the windpipe free. If there be
breathing--wait and watch; if not, or if it fail,--
"To Excite Respiration--3. Turn the patient well and instantly on his
side, and--4. Excite the nostrils with snuff, the throat with a feather,
etc., dash cold water on the face previously rubbed warm. If there be no
success, lose not a moment but instantly--
"To Imitate Respiration--5. Replace the patient on his face, raising and
supporting the chest well on a folded coat or other article of dress;--6.
Turn the body very gently on the side and a little beyond, and then
briskly on the face, alternately; repeating these measures deliberately,
efficiently, and perseveringly fifteen times in the minute, occasionally
varying the side; when the patient reposes on the chest, this cavity is
compressed by the weight of the body, and expiration takes place; when he
is turned on the side, this pressure is removed, and inspiration occurs.
7. when the prone position is resumed, make equable but efficient
pressure, with brisk movement, along the back of the chest; removing it
immediately before rotation on the side: the first measure augments the
expiration, the second commences inspiration. The result
is--Respiration;--and, if not too late,--Life.
"To induce Circulation and Warmth--8. Rub the limbs upwards, with firm
grasping pressure and with energy, using handkerchiefs, etc. by this
measure the blood is propelled along the veins towards the heart. 9. Let
the limbs be thus dried and warmed, and then clothed, the bystanders
supplying coats, waistcoats, etc. 10.. Avoid the continuous warm-bath,
and the position on or inclined to the back."
Litter for the Wounded.--If a man be wounded or sick, and has to be
carried upon the shoulders of others, make a little for him in the Indian
fashion; that is to say, cut two stout poles, each 8 feet long, to make
its two sides, and three other cross-bars of 2 1/2 feet each, to be
lashed to them. Then supporting this ladder-shaped framework over the
sick man as he lies in his blanket, knot the blanket up well to it, and
so carry him off palanquin-fashion. One cross-bar will be just behind his
head, another in front of his feet; the middle one will cross his
stomach, and keep him from falling out; and there will remain two short
handles for the carriers to lay hold of. The American Indians carry their
wounded companions by this contrivance after a fight, and during a
hurried retreat, for wonderful distances. A king of waggon-roof top can
easily be made to it, with bent boughs and one spare blanket. (See
Palanquin.)
[Black and white sketch of two 'Indians' carrying litter].
SURVEYING INSTRUMENTS.
In previous editions I reprinted here, with a few trifling alterations,
part of a paper that I originally communicated to the Royal Geographical
Society, and which will be found at the end of their volume for 1854. In
addition to it, communications are published there from Lieutenant Raper,
Admiral FitzRoy, Admiral Smyth, Admiral Beechey, and Colonel Sykes; the
whole of which was collected under the title of 'Hints to Travellers;'
they were printed in a separate form and widely circulated. When the
edition was exhausted, a fresh Committee was appointed by the Council of
the Royal Geographical society, consisting of Admiral sir George Back,
Admiral R. Collinson, and myself, to revise the pamphlet thoroughly. This
process was again gone through in 1871, and now the pamphlet is so much
amended and enlarged that I should do no good by making extracts. It is
much better that intending travellers should apply for this third edition
of the 'Hints to Travellers' at the society's rooms, 1, Savile Row: for
it gives a great deal of information upon instruments that they would
find of real value. Its price is 1s.
Porters for delicate Instruments.--Entrust surveying instruments and
fragile articles to come respectable old savage, whose infirmities compel
him to walk steadily. He will be delighted at the prospect of picking up
a living by such easy service.
Measuring low angles by reflexion.--an ordinary artificial horizon is
useless for very low angles. They can be measured to within two or three
minutes, by means of a vertical point of reference obtained in the
following manner:--Tie two pieces of thread, crossing each other at two
feet above the ground, put the vessel of mercury underneath it, and look
down upon the mercury. When the eye is so placed, that the crossed
threads exactly cover their reflexion, the line of sight is truly
vertical; and, if the distant object be brought down to them by the
sextant, the angle read off will be 90 degrees + altitude. Captain
George's arrangement of glass floating on mercury (made by Cary, Fleet
Street, London), allows of very low angles being observed, but the use of
this instrument requires considerable caution as to the purity of the
mercury and the cleanliness of the glass.
Substitute for glass roof to Horizon.--For want of a glass roof to place
over the mercury a piece of gauze stretched over the vessel will answer
very tolerably for the purpose of keeping off the wind. The diameter of
the pupil of the eye is so large, compared to the thickness of the
threads of the gauze, that the latter offer little impediment to a clear
view of the image.
Silvering Glasses for Sextants.--"Before taking leave of this subject it
may not be unimportant to describe the operation of silvering the glasses
of sextants, as those employed on surveying duties very frequently have
to perform the operation.
"The requisites are clean tinfoil and mercury (a hare's foot is
handy)--lay the tinfoil, which should exceed the surface of the glass by
a quarter of an inch on each side, on a smooth surface (the back of a
book), rub it out smooth with the finger, add a bubble of mercury, about
the size of a small shot, which rub gently over the tinfoil until it
spreads itself and shows a silvered surface, gently add sufficient
mercury to cover the leaf so that its surface is fluid. Prepare a slip of
paper the size of the tinfoil. Take the glass in the left hand,
previously well cleaned, and the paper in the right. Brush the surface of
the mercury gently to free it from dross. Lay the paper on the mercury,
and the glass on it. Pressing gently on the glass, withdraw the paper.
turn the glass on its face, and leave it on an inclined plane to allow
the mercury to flow off, which is accelerated by laying a strip of
tinfoil as a conductor to its lower edge. The edges may, after twelve
hours' rest, be removed. In twenty-four hours give it a coat of varnish,
made from spirits of wine and red sealing-wax. It may be as well to
practise on small bits of common glass, which will soon prove the degree
of perfection which the operator has attained." (Admiral Sir E. Belcher.)
MEMORANDA AND LOG-BOOKS.
Best form for Memoranda.--I have remarked that almost every traveller who
is distinguished for the copiousness and accuracy of his journals, has
written them in a remarkably small but distinct handwriting. Hard
pencil-marks (HHH pencils) on common paper, or on metallic paper are very
durable. Dr. Barth wrote his numerous observations entirely in
Indian-ink. He kept a tiny saucer in his pocket, rubbed with the ink;
when he wanted to use it, he rubbed it up with his wetted finger-tip, or
resupplied it with fresh ink, and filled his pen and wrote. Captain
Burton wrote very much in the dark, when lying awake at night; he used a
board with prominent lines of wood, such as is adopted by the blind. It
is very important that what is written should be intelligible to a
stranger after a long lapse of time. A traveller may die, and his
uncompleted work perish with him; or he may return, and years will pass
by, and suddenly some observations he had made will be called in
question.
Professor J. Forbes says:--"The practice which I have long adopted is
this:--to carry a memorandum-book with Harwood's prepared paper" (in this
point of detail I do not concur; see next paragraph) "and metallic
pencil, in which notes and observations and slight sketches of every
description, are made on the spot, and in the exact order in which they
occur. These notes are almost ineffaceable, and are preserved for
reference. They are then extended, as far as possible, every evening with
pen and ink, in a suitable book, in the form of a journal; from which,
finally, they may be extracted and modified for any ultimate purpose. The
speedy extension of memoranda has several great advantages: it secures a
deliberate revision of observations, whether of instruments or of nature,
whilst further explanation may be sought, and very often whilst
ambiguities or contradictions admit of removal by a fresh appeal to
facts. By this precaution, too, the risk of losing all the fruits of some
weeks of labour, by the loss of a pocket-book, may be avoided."
It has occurred to me, frequently, to be consulted about the best was of
keeping MSS. Captain Blakiston, who surveyed the northern part of the
Rocky Mountains, and subsequently received the medal of the Royal
Geographical Society, for his exploration and admirable map of the
Yang-tse-Kiang, in China, paid great attention to the subject: he was
fully in possession of all I had to say on the matter; and I gladly quote
the method he adopted in North America, with slight modifications,
according to the results of his experience, and with a few trivial
additions of my own. For the purposes of memoranda and mapping data, he
uses three sets of books, which can be ordered at any lithographer's:--
No. 1. pocket Memorandum Book, measuring three inches and a half by five,
made of strong paper. (Captain Blakston did not use, and I should not
advise travellers to use, "prepared" paper, for it soon becomes rotten,
and the leaves fall out; besides that, wet makes the paper soppy.) The
books are paged with bold numbers printed in the corners; two faint red
lines are ruled down the middle of each page, half an inch apart, to
enable the book to be used as a field-surveyor's book when required. In
this pocket=book, every single thing that is recorded at all, is
originally recorded with a hard HHH pencil. Everything is written
consecutively, without confusion or attempt to save space. There may
easily be 150 pages in each of these books; and a sufficient number
should be procured to admit of having at least one per month. Do not
stint yourself in these.
No. 2. Log-Book.--This is an orderly way of collecting such parts of the
surveying material as has been scattered over each day in your note-book.
It is to be neatly written out, and will become the standard of future
reference. By using a printed form, the labour of drawing up the log on
the one hand, and that of consulting it on the other, will be vastly
diminished. I give Captain Blakiston's form, in pages 28, 29, and I would
urge intending travellers not to depart from it without very valid
reasons, for it is the result of considerable care and experience. The
size in which the form is printed here is not quite accurate, because the
pages of this book are not large enough to admit of it, but the
proportion is kept. The actual size is intended to be five and a half
inches high and nine inches wide, so that it should open freely along one
of the narrow sides of the page, in the way that all memoranda books
ought to open. Four pages go to a day; of these the pages 1 and 2 are
alone represented in this book, pages 3 and 4 being intended to be left
blank.
[P 28 and p 29 show samples of the log book pages being described].
The bold figures 17 and 18 in the right-hand corners of the form I give,
show how the pages should be numbered. The lines in p. 18 should be faint
blue.
No. 3. Calculation Book.--This should be of the same size and shape as
the Log Book, and should contain outline forms for calculations. The
labour and confusion saved by using these, and the accuracy of work that
they ensure, are truly remarkable. The instruments used, the observations
made, and especially the tables employed, are so exceedingly diverse,
that I fear it would be to little purpose if I were to give special
examples: each traveller must suit himself. I will, therefore, simply
make a few general remarks on this subject, in the following paragraph.
Number of Observations requiring record.--A traveller does excellently,
who takes latitudes by meridian altitudes, once in the twenty-four hours;
a careful series of lunars once a fortnight, on an average; compass
variations as often; and an occulation now and then. He will want,
occasionally, a time observation by which to set his watch (I am
supposing he uses no chronometer). He ought therefore to provide himself
with outline forms for calculating these observations, even if he finds
himself obliged to have them printed or lithographed on purpose; and in
preparing them, he should bear the following well-known maxims in mind:--
Let all careful observations be in doubles. If they be for latitudes,
observe a star N. and a star S.; the errors of your instruments will then
affect the results in opposite directions, and the mean of the results
will destroy the error. So, if for time, observe in doubles, viz., a star
E. and a star W. Also, if for lunars, let your sets be in doubles--one
set of distances to a star E. of moon, and one to a star W. of moon.
Whenever you begin on lunars, give three hours at least to them, and
bring away a reliable series; you will be thus possessed of a certainty
to work upon, instead of the miserably unsatisfactory results obtained
from a single set of lunars taken here and another set there, scattered
all over the country, and impossible to correlate. A series should
consist of six sets, each set including three simple distances. Three of
these sets should be to a star or stars E. of moon, and three to a star
or stars W. of moon. Lunars not taken on the E. and W. plan are almost
worthless, no matter how numerous they may be, for the sextant, etc.,
might be inaccurate to any amount, and yet no error be manifest in their
results. But the E. and W. plan exposes errors mercilessly, and also
eliminates them. One of the best authorities on the requirements of
sextant observations in rude land travel, the Astronomer Royal of Cape
Town, says to this effect:--"Do not observe the altitude of the star in
taking lunars, but compute it. The labour requisite for that observation
is better bestowed in taking a large number of distances." So much
delicacy of hand and of eyesight is requisite in taking lunars that shall
give results reliable to seven or eight miles, and so small an exertion
or flurry spoils that delicacy, that economy of labour and fidget is a
matter to be carefully studied.
These things being premised, it will be readily understood that outline
forms sufficient for an entire series of lunars will extend over many
pages--they will, in fact, require eighteen pages. There are four sets of
observations for time:--one E. and one W., both at beginning and close of
the whole; one for latitudes N. and S.; six for six sets of lunars, as
described above; six for the corresponding altitudes of the stars, which
have to be computed; and, finally, one page for taking means, and
recording the observations for adjustment, etc. Each double observation
for latitude would take one page; each single time observation one page;
and each single compass variation one page. An occulation would require
three pages in all; one of which would be for time. At this rate, and
taking the observations mentioned above, a book of 500 pages would last
half a year. Of course where the means of transport is limited,
travellers must content themselves with less. Thus Captain Speke, who
started on his great journey amply equipped with log-books and
calculation-books, such as I have described, found them too great an
incumbrance, and was compelled to abandon them. The result was, that
though he brought back a very large number of laborious observations,
there was a want of method in them, which made a considerable part of his
work of little or no use, while the rest required very careful treatment,
in order to give results commensurate with their high intrinsic value.
MEASUREMENTS.
Distance.--To measure the Length of a Journey by Time.--The pace of a
caravan across average country is 2 1/2 statute, or 2 geographical, miles
per hour, as measured with compasses from point to point, and not
following the sinuosities of each day's course; but in making this
estimate, every minute lost in stoppages by the way is supposed to be
subtracted from the whole time spent on the road. A careful traveller
will be surprised at the accuracy of the geographical results, obtainable
by noting the time he has employed in actual travel. Experience shows
that 10 English miles per day, measured along the road--or, what is much
the same thing, 7 geographical miles, measured with a pair of compasses
from point to point--is, taking one day with another, and including all
stoppages of every kind, whatever be their cause,--very fast travelling
for a caravan. In estimating the probable duration of a journey in an
unknown country, or in arranging an outfit for an exploring expedition,
not more than half that speed should be reckoned upon. Indeed, it would
be creditable to an explorer to have conducted the same caravan for a
distance of 1000 geographical miles, across a rude country, in six
months. These data have, of course, no reference to a journey which may
be accomplished by a single great effort, nor to one where the
watering-places and pasturages are well known; but apply to an
exploration of considerable length, in which a traveller must feel his
way, and where he must use great caution not to exhaust his cattle, lest
some unexpected call for exertion should arise, which they might prove
unequal to meet. Persons who have never travelled--and very many of those
who have, from neglecting to analyse their own performances--entertain
very erroneous views on these matters.
Rate of Movement to measure.--a. When the length of pace etc., is known
before beginning, to observe.--A man or a horse walking at the rate of
one mile per hour, takes 10 paces in some ascertainable number of
seconds, dependent upon the length of his step. If the length of his step
be 30 inches, he will occupy 17 seconds in making 10 paces. Conversely,
if the same person counts his paces for 17 seconds, and finds that he has
taken 10 in that time, he will know that he is walking at the rate of
exactly 1 mile per hour. If he had taken 40 paces in the same period, he
would know that his rate had been 4 miles per hour; if 35 paces, that it
had been 3.5, or 3 1/2 miles per hour. Thus it will be easily
intelligible, that if a man knows the number of seconds appropriate to
the length of his pace, he can learn the rate at which he is walking, by
counting his paces during that number of seconds and by dividing the
number of his paces so obtained, by 10. In short the number of his paces
during the period in question, gives his rate per hour, in miles and
decimals of a mile, to one place of decimals. I am indebted to Mr.
Archibald Smith for this very ingenious notion, which I have worked into
the following Tables. In Table I., I give the appropriate number of
seconds corresponding to paces of various lengths. I find, however, that
the pace of neither man nor horse is constant in length during all rates
of walking; consequently, where precision is sought, it is better to use
this Table on a method of approximation. That is to say, the traveller
should find his approximate rate by using the number of seconds
appropriate to his estimated speed. Then, knowing the length of pace due
to that approximate rate, he will proceed afresh by adopting a revised
number of seconds, and will obtain a result much nearer to the truth than
the first. Table I. could of course be employed for finding the rate of a
carriage, when the circumference of one of its wheels was known; but it
is troublesome to make such a measurement. I therefore have calculated
Table II., in terms of the radius of the wheel. The formulae by which
the two Tables have been calculated are, m=l x 0.5682 for Table I., and
m=r x 3.570 for Table II., where m is the appropriate number of seconds;
l is the length of the pace, or circumference of the wheel; and r is the
radius of the wheel.
The Tables will be found on the next page.
[Tables I and II appear on p 34].
b. When the length of Pace is unknown till after observation.--In this
case, the following plan gives the rate of travel per hour, with the
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