SUPPLEMENTARY REPORT ON METEOROLOGY. 99 
(3.) from experiments on refrigeration in air once 
saturated, then warmed. . .. .. . . ‘01140 
nearly coincident with one another, and with the theoretical 
determination. 
181. Bohnenberger* had already obtained a value sensibly 
identical, which probably was not known to Dr. Apjohn at the 
time he made his experiments ; for English inches and Fahren- 
heit degrees, he obtained — 
First, from 56 observations . ... . m=+°0114 
Afterwards, from 45, which he preferred . "011398 
182, M. Kamtz, in avery valuable paper on the results of his 
extensive observations in Switzerland, has given his formula in 
a slightly different form, but which indicates an almost precise 
coincidence between theory and experiment, both for the case 
where the thermometer is above freezing and below ; for in the 
latter case equally the principle holds, only we must allow for 
the latent heat absorbed in liquefying as well as vaporizing the 
water. Including the barometric formula, M. Kamtz writes 
the second term of the formula for the elasticity thus : 
— 0°001004475 (¢ — #') b, 
b being the barometric height in French lines, the standard 
barometric height 336 lines, by which the co-efficient (which is 
for Reaumur’s scale) has been already divided. 
183. The above expression is the theoretical one above 0° R. 
The theoretical one below O° R. is 
— 0:0009375 (¢ — #’) b. 
184. These two numbers, deduced @ posteriori from the Swiss 
observations, give 
° Faulhorn . . ‘0010026 34 obs. 
pene OB rae PS oo doasd. 31 
Below 0° Rf en . . 000945014 15 
33 
Zurich . . . *0009995 11 
from direct comparison with the dew-point. 
185. I have given these numbers, that their coincidence may be 
perceived. Again, to compare them with Apjohn’s and others, 
we may take those at the Faulhorn and reduce them to English 
measures and a mean barometric pressure, when we shall 
obtain 
Above 32° Fahr. . . . m=:0118 
Below 32° Fahr. . . . m= ‘0112 
* Suerman, p. 88. + Poggendorff, xxx. 33. 
2 
= 
tw 
