212 
THE FOREST IN WINTER. 
observation, because there are few meteorological stations in 
such situations. In the Northeastern border States of the 
American Union, the ground in the deep woods is covered 
with snow four or five months, and the proportion of water 
which falls in snow does not exceed one fifth of the total pre¬ 
cipitation for the year.* Although, in the open grounds, snow 
and ice are evaporated with great rapidity in clear weather, 
even when the thermometer stands far below the freezing 
point, the surface of the snow in the woods does not indicate 
much loss in this way. Very small deposits of snowflakes 
remain unevaporated in the forest, for many days after snow 
let fall at the same time in the cleared field has disappeared 
without either a thaw to melt it or a wind powerful enough to 
drift it away. Even when bared of their leaves, the trees of a 
wood obstruct, in an important degree, both the direct action 
of the sun’s rays on the snow, and the movement of drying 
and thawing winds. 
Dr. Piper records the following observations: “ A body of 
snow, one foot in depth, and sixteen feet square, was protected 
from the wind by a tight board fence about five feet high, 
while another body of snow, much more sheltered from the 
sun than the first, six feet in depth, and about sixteen feet 
square, was fully exposed to the wind. When the thaw came 
on, which lasted about a fortnight, the larger body of snow 
was entirely dissolved in less than a week, while the smaller 
body was not wholly gone at the end of the second week. 
“ Equal quantities of snow were placed in vessels of the 
same kind and capacity, the temperature of the air being sev¬ 
enty degrees. In the one case, a constant current of air was 
kept passing over the open vessel, while the other was pro¬ 
tected by a cover. The snow in the first was dissolved in 
sixteen minutes, while the latter had a small unthawed propor¬ 
tion remaining at the end of eighty-five minutes.” f 
The snow in the woods is protected in the same way, 
though not literally to the same extent as by the fence in one 
* Thompson’s Vermont, appendix, p. 8. 
t Trees of America , p. 48. 
