264 J. Croll—Geological Climatology. 
It is assumed, in this objection, that because the heat received 
from the sun by an area is more than sufficient to melt all the 
snow that falls on it, no permanent accumulation of snow and 
ice can take place. It is assumed that the quantity of snow 
d ice melted must be proportional to the heat received. 
Suppose that on a certain area a given amount of snow falls 
cut off by the atmosphere has been made, if it be found that 
the quantity remaining is far more than sufficient to melt the 
snow, it is then assumed that the snow must be melted, and 
for the first time such an assumption looks very plausible, 
but a little reflection will show that it is most superficial. 
The assumption is at the very outset totally opposed to known 
facts. Take the lofty peaks of the Himalayas and Andes as an 
example. Few, I suppose, would admit that at these great 
elevations as much as fifty per cent of the sun’s heat could be 
cut off. But if fifty per cent reaches the snow this would be 
sufficient to melt fifty feet of ice, and this no doubt is more 
than ten times the quantity which actually requires to be 
melted. Notwithstanding all this the snow is never melted 
but remains permanent. ake as another example South 
Georgia in the latitude of England. Suppose we assume that 
one-half of the sun’s heat is cut off by the clouds and fogs 
* Geological Magazine, April, 1880. 
