560 Home Nature-Study Course. 



THE MAKING OF SOILS. 



John ,W. Spencer. 



In the issue of October, I suggested that the teacher take her 

 children down to the brook on some Friday afternoon for a field excur- 

 sion. Among the things oi interest to be seen I spoke of some mills 

 where stone flour was in process of being made. 



I did not then have the space to tell you all that I should about the 

 process of stone flour being produced by other mills than those I men- 

 tioned. If the teacher has learned her physical geography to good 

 purpose, she should be able to give her pupils a story full of interest 

 concerning the Great Glacier that slipped down from the north, and a 

 part of which spread over the State of New York. 



In telling this story, take pains that the pupils do not confuse 

 glaciers with avalanches, monks, mountain huts and St. Bernard dogs 

 with small kegs strapped beneath their necks. The Alpine avalanches 

 move with a rush and a roar. Glaciers may be found to-day in the 

 Alps, Greenland and Alaska, and they move very slowly in comparison, — 

 some of them but a few feet during a year, others 75 feet a day. 



I do not know for how long a time the Great Northern Glacier covered 

 the Eastern States but that such a condition existed, we have abundant 

 proof. (For account of glacier and glacial period see " Introduction to 

 Physical Geography," Gilbert & Brigham.) 



LESSON CXXX. 

 evidence of the great northern glacier. 



Purpose. — To interest the pupils in observing that boulders scattered 

 over many portions of New York State are not like the local rock; and 

 also to teach them to look for glacial scratches. 



Material. — The hard round stones of granite which the pupils will 

 be able to collect in the neighborhood of the school. If there are any 

 bare rocks in the vicinity look on them for glacial scratches which show 

 in parallel lines. 



The teacher can call the attention of her pupils to the granite 

 boulders that are so frequently found over field and woodland of all that 

 part of our country once covered by the Great Northern Glacier. She 

 may call them visitors from the north. Why do we know that they have 

 come from far away? For the simple reason that in all the stone 

 quarries in New York no granite of that peculiar kind is found except 



