CHAPTER IV 



SOIL 



Hozv Soils Are Made. A good deal has been said 

 about soils, and it may interest you to discuss how soils 

 are made. The soil in Wisconsin, and most of the 

 northern states, contains much hard gravel mixed with 

 fine soil. This "drift," as it is called, varies in depth 

 from a few inches to hundreds of feet. Underneath 

 this drift is solid rock. Any "well-driller" will tell 

 you this. He can also tell you how far he has had to 

 go down into the earth, before striking rock, in the dif- 

 ferent wells that he has drilled. Further he will tell 

 you that this rock does not resemble the stone or 

 gravel above it. Where, then, did this drift come 

 from ? 



Glacial Drift and Rock Decay. Many years ago, 

 before man made his appearance on the earth, a great 

 mass of ice and snow, called a glacier, moved down 

 from the polar regions, scraping up the loose earth, 

 rocks, and stones as it passed slowly along, crushing 

 and grinding them together, wearing off hilltops, fill- 

 ing up valleys and depositing the gravelly material 

 from which this soil, wherein the farmer now sows his 

 seed, is made. The reason why the stones that may 



