98 THE FOEMS OF WATER IN 



less extent, must be far more effectual high up the 

 vralley than at the end of the glacier. 



§ 36. Birth of a Crevasse : Reflections. 



249. Preserving the notion that we are working to- 

 gether, we will now enter upon a new field of enquiry. 

 We have wrapped up our chain, and are turning home- 

 wards after a hard day's work upon the Glacier du 

 Geant, when under our feet, as if coming from the 

 body of the glacier, an explosion is heard. Somewhat 

 startled, we look enquiringly over the ice. The sound 

 is repeated, several shots being fired in quick succession. 

 They seem sometimes to our right, sometimes to our 

 left, giving the impression that the glacier is breaking 

 all round us. Still nothing is to be seen. 



250. We closely scan the ice, and after an hour's 

 strict search we discover the cause of the reports. They 

 announce the birth of a crevasse. Through a pool upon 

 the glacier we notice air bubbles ascending, and find the 

 bottom of the pool crossed by a narrow crack, from 

 which the bubbles issue. Eight and left from this pool 

 we trace the young fissure through long distances. It 

 is sometimes almost too feeble to be seen, and at no 

 place is it wide enough to admit a knife-blade. 



251. It is difficult to believe that the formidable 

 fissures among which you and I have so often trodden 

 with awe, could commence in this small way. Such, 

 however, is the case. The great and gaping chasms om 



