The Story -Book of the Fields 



carried away by the rain and deposited in 

 the valleys. Broken stones, sand, mud and 

 soil have, for the most part, no other origin. 

 The ice by its power of expansion has detached 

 them from the tops of the mountains, and 

 the water has swept them away and carried 

 them further. We can form an idea of the 

 action of ice, how it crumbles the rocks to 

 turn them into earth and to enrich the 

 valleys, by examining the surface of a beaten 

 road at the time of thaw. 



This surface, which was firm under foot 

 before the frost, is broken up by the thaw 

 and here and there raised up in little 

 crumbling clods. With the coming of the 

 frost the moisture with which the soil was 

 impregnated became ice which, increasing in 

 volume and expanding, reduced the surface of 

 the road to fragments. When the thaw sets 

 in, these fragments, no longer held together 

 by the ice, form mud first, and afterwards 

 dust. It is in an exactly similar way that 

 the soil has been formed by fragments of 

 rocks of every kind, reduced to powder by 

 ice. 



But agricultural ground not only contains 

 powdered mineral matters, it contains also 

 a compost, provided independently by the 



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