48 DISCUSSIONS IN CLIMATOLOGY. 



much as 50 per cent, of the sun's heat could be cut off. 

 But if 50 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. Take, 

 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 which 

 prevail to such an extent in that place, still the 

 remaining half would be sufficient to melt upwards 

 of thirty feet of ice, which is certainly more than the 

 equivalent of all the snow which falls ; yet this island 

 is covered with snow and ice down almost to the sea- 

 shore during the whole year. Take still: . another 

 example, that of Greenland. The quantity of heat 

 received between latitudes 60° and 80°, which is that 

 of Greenland, is, according to Meech, one half that 

 received at the equator ; and were none cut off, it 

 would be sufficient to melt fifty feet of ice. The 

 annual precipitation on Greenland in the form of 

 snow and rain, according to Dr. Rink, amounts to only 

 twelve inches ; and two inches of this he considers is 

 never melted, but is carried away in the form of ice- 

 bergs. Mr. Hill maintains* that, owing to the great 

 thickness of the air traversed by the sun's rays, and 

 the loss resulting from the great obliquity of reflection, 

 the amount of heat reaching the ground would be 

 insufficient to melt more than sixteen feet of ice. 

 Supposing we admit this estimate to be correct, still 

 this is nineteen times more than is actually melted. 

 The sun melts only ten inches, notwithstanding the 

 fact that it has the power to melt sixteen feet. 



* " Geological Magazine," April, 1880. 



