48 TDE F0EMS OF WATER IN 



§ 15. Questioning the Glaciers. 



1 24. I would now ask you to consider for a moment 

 the facts which such an excursion places in our posses- 

 sion. The snow through which we have in idea trudged 

 is the snow of last winter and spring. Had we placed 

 last August a proper mark upon the surface of the 

 snow, we should find it this August at a certain depth 

 beneath the surface. A good deal has been melted 

 by the summer sun, but a good deal of it remains, and 

 it will continue until the snows of the coming winter 

 fall and cover it. This again will be in part preserved 

 till next August, a good deal of it remaining until it is 

 covered by the snow of the subsequent winter. We thus 

 arrive at the certain conclusion that on the plateau 

 of the Col du Geant the quantity of snow that falh 

 annually exceeds the quantity melted. 



125. Had we come in the month of April or May, we 

 should have found the glacier below the ice-fall also 

 covered with snow, which is now entirely cleared away 

 by the heat of summer. Nay, more, the ice there is 

 obviously melting, forming running brooks which cut 

 channels in the ice, and expand here and there into 

 small blue-green lakes. Hence you conclude with 

 certainty that below the ice-fall the quantity of frozen 

 material falling upon the glacier is less than the quantity 

 melted. 



126. And this forces upon us another conclusion? 



