SCIENTIFIC OUTFIT. 
0 
the boiling-point thermometers. Two are required, because simul¬ 
taneous observations are important. Kecollect that such observa¬ 
tions, 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 at equal elevations. 
“ Watkin Mountain ” Aneroid — 
This instrument can be put into action when required, and, when 
thrown out of action, is not influenced by the variations in at¬ 
mospheric pressure. A series of experiments with it has been 
carried out by Mr. Edward Whymper, the results of which have 
been published in The Geographical Journal , January, 1899. It has 
also been used by other travellers, who have reported satis¬ 
factorily on its performance. As, however, this is a new instru¬ 
ment, travellers will do well not to place implicit confidence in it, 
until it has been further tested by explorers. 
Eor barometers, see p. 7, and Yol. II., p. 25 et sep 
Mapping Instruments 
A small leather pocket-case of drawing instruments, containing, 
among other things, hair-compasses, drawing-pen, and a rect¬ 
angular 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 6 inches 
in diameter; one of vulcanite, 6 inches, all graduated, like the 
prismatic compass, from 0° to 360°. 
A metal ruler of 1 foot or more in length, graduated to tenths of 
an inch, with diagonal scale: 2 dozen artists pins. Medium size 
measuring tape, say 50 feet; pocket ditto, 2 yards. 
Stationery , cfcc.— 
An artist’s board, not less than 8 inches by 13, made of light, Well- 
seasoned pine, and what cabinet-makers call “ framed/’ to rule 
and draw upon. 
