J. Crol—Geological Climatology. 259 
increase in the quantity of snow falling during that season. 
his very obvious result follows as a necessary consequence 
from the fact that the moisture which now falls in the form of 
rain would then fall as snow. But Professor Newcomb actu- 
ally states that he cannot accept the conclusion that this would 
ead to more snow. : 
Influence of a Snow-covered Surface—l have argued that 
this accumulation of snow would lower the summer tempera- 
ture, and tend to prevent the disappearance of the snow, and 
have assigned three reasons for this conclusion :— 
first.—Direct radiation. The snow, for physical reasons 
well known, will cool the air more rapidly than the sun’s rays 
will heat it. This is shown from the fact that in Greenland, a 
show and ice-covered country, a thermometer exposed to the 
direct radiation of the sun has been observed to stand above 
india. Were the snow and icy mantle removed, a snow shower 
in summer would be as rare a phenomenon in those regions as 
it would be in the south of England. . 
Second.—* The rays which fall on snow and ice are to a great 
extent reflected back into space. But those that are not reflected, 
This reason is also regarded as absurd. The heat of the sun 
during the perihelion summer would, he says, suffice to melt 
the whole accumulation of winter snow in three or four days. 
he reader,” he continues, “can easily make a computation 
of the incredible reflecting power of the snow and of the unex- 
* Geological Magazine for January, 1880, p. 12. 
