114 



THE FORMS OF WATER 



Fro. 9. 



tkm of the sand is favorable, and the action 

 wifficiently prolonged, you have little moun- 

 tains formed, sometimes singly, and some- 

 times grouped so as to mimic the Alps 

 themselves. The Sand Cones of the Mer de 

 Glare are not striking ; but on the Gorncr, 

 the Aletseh, the Morteratsch, and other gla- 

 cieis, they form singly and in groups, reach- 

 ing sonic-limes a height of ten or twenty 

 feet. 



44. THE GLACIER MILLS OR MOULINS. 



29:J You and I have learned by long ex 

 poiience the character of the Mer de Glace. 

 We have marched over it daily, with a defi- 

 nite object in view, but we have not closed 

 our eyes to nher objects. It is from side 

 glimpses of things which are not at the mo 

 ineut occupying our attention that fresh sub- 

 jects of inquiry arise in scientific investiga- 

 tion. 



21)4. Thus in marching over the ice near 

 Trclaporte we were often struck by a sound 

 resembling low rumbling thunder. We 

 subsequently sought out the origin of this 

 sound, and found it. 



25)5. A large area of this portion of the 

 glacier is unbroken. Driblets of water have 

 room to form rills, rills to unite and form 

 Rtifjims, streams to combine to form rush- 

 iiur brooks, which sometimes cut deep chan- 

 nels in the ice. Sooner or later these streams 

 reach a strained portiou of the glacier, where 

 a crack is formed across the stream. A way 

 is thus opened for the water to the bottom of 

 the glacier. By long action the stream 

 hollows out a shaft, the crack thus becoming 

 the starting-point of a funnel of unseen 

 depth, into which the water leaps with the 

 sound of thunder. 



290. This funnel and its cataract form p 

 glacier Mill or Moulin. 



v 2i7. Let me grasp your hand firmly while 

 you stand upon the edge of this shaft and 

 'look into it. The hole, with its pure blue 

 shimmer, is beautiful, but it is terrible. Ia- 



Fio. 10. 



cautious persons have fallen into these 

 shafts, a second or two of bewilderment bo 

 ing followed by sudden death. But caution 

 upon the glaciers and mountains ought, by 

 habit, to be made a second nature to explor- 

 ers like you and me. 



298. The crack into which the stream first 

 descended to form the moulin, moves down 

 with the glacier. A succeeding portion of 

 the ice reaches the place where the breaking 

 strain is exerted. A new crack is then 

 formed above the moulin, which is thence- 

 forth forsaken by the stream, and moves 

 downward as an empty shaft. Here upon 

 the Mer de Glace, in advance of the Grand 

 Moulin we see no less than six of these for- 

 saken holes. Some of them we sound to a 

 depth of 90 feet. 



299. But you and I both wish to deter- 

 mine, if possible, the entire depth of the Mer 

 de Glace. The Grand Moulin offers a chance 

 of doing this which we must not neglect 



