SCIENTIFIC OUTFIT. 
3 
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. 43 for 
further particulars.) 
Mem. .-—Chronometers are designedly omitted from this list, on 
account of the proved difficulty 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 1| 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. {See pp. 10,11 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, if made of iron, 
they will affect the compass reading when taking the bearing of 
a heavenly body at night, and should be constructed for Jong 
journeys and hot climates, to be used with oil, and furnished 
with a large wick. A candle lantern is convenient where 
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