IMPORTANCE OF SNOW. 911 
The snow in contact with the earth now begins to melt, with 
greater or less rapidity, according to the relative temperature 
of the earth and the air, while the water resulting from its dis- 
solution is imbibed by the vegetable mould, and carried off by 
infiltration so fast that both the snow and the layers of leaves 
in contact with it often seem comparatively dry, when, in fact, 
the under-surface of the former is in a state of perpetual thaw. 
No doubt a certain proportion of the snow is given off to the 
atmosphere by direct evaporation, but in the woods, the pro- 
tection against the sun by even leafless trees prevents much 
loss in this way, and besides, the snow receives much moisture 
from the air by absorption and condensation. Very little 
Williams’s thermometer was sunk to the depth of ten inches, and gave the fol- 
lowing results: 
Temperature Temperature 
TIME, of ground in of ground in Difference, 
pasture, woods. 
Lay, Pee Mla te Veni Nts as 52 4G 6 
ARO fele ts -isiaveteiaycl at ctl hofar's 57 48 9 
SIRES ee Oe cen Genicsene cs qeeeer 64 51 13 
Soe (elic lOvE SSR eer eee pone 62 51 if 
Sleeper. Pets MONE a 62 51 11 
te ad ISIA ATS: Se oS cote oo arelenre olere 654 553 10 
Negotiate «to dss icmia dna ackes 68 58 10 
NSIS SORES SEE oo neh an 594 55 4} 
SETTLE OSE aE BR GOBEAECSHebsMone 593 55 4} 
6 ally UREA ERM n rine Sia aint 59S 55 4} 
MeN Lele Mi eps 52 -a ef mtanatonteloaeiae oat 49 49 0 
TIN OMe ibis Gara 8 «codes te tt atoiarstartys 43 43 0 
BEE EOS cab cin synysscha arid wiasaieinie oi sharers 435 43% 0 
On the 14th of January, 1791, in a winter remarkable for its extreme 
severity, he found the ground, on a plain open field where the snow had been 
blown away, frozen to the depth of three feet and five inches; in the woods 
where the snow was three feet deep, and where the soil had frozen to the 
depth of six inches before the snow fell, the thermometer, at six inches 
below the surface of the ground, stood at 39°. In consequence of the cover- 
ing of the snow, therefore, the previously frozen ground had been thawed 
and raised to seven degrees above the freezing-point.—WILLIAMs’s Vermont, 
de opi de 
Boussingault’s observations are important, Employing three thermometers, 
