Teachers' Leaflet. 



561 



in the Adirondacks. The statement is made that away up north in the 

 British possessions, stone of the identical kind as the boulders is found. 

 That being the case, it is reasonable to suppose that those rocks were 

 caught up in the mass of ice and brought down here. When weather 

 conditions changed, and the glacier retreated or melted back, the stones 

 were left on the spot where the glacier dropped them. As they came 

 floating down with the slowly moving ice, great pushing of rocks against 

 other rocks went on. In this rubbing and grinding of big stones into 

 little stones, the same results followed as was the case of the stones in 

 the stocking I spoke of in the October issue. To a geologist trained 

 in such observation, scratches may be found where one boulder made 

 grooves in another boulder. 



I have had a stone for a number of years that shows glacial scratches. 

 It is not a large one — about the proper size for throwing at a wood- 

 chuck — and it was broken from a larger piece. Besides the glacial 

 scratches it bears other evidences of roughing it as a traveler for all the 

 edges are rounded and smooth. 



What happened to my wood- 

 chuck stone happened to millions 

 and millions of other stones big 

 and little. By this, the teacher will 

 understand that glacial action was 

 of great importance as a mill for 

 making stone flour. 



Parenthetically, let me say that 

 to me physical geography is one of 

 the most interesting subjects taught 

 in our schools and is an easier sub- 

 ject for interesting children than 

 that of Greek myths. It has a 

 probability of truth and is not a 

 figment of the imagination. If I 



hear children complain of dullness . , , ,. 



r , . . X 1 • I 1 -^ scratched limestone pehble taken 



of this topic I think they must ^,,^ ^ ^^^^.^^ ^^.^ 



have some peculiar cast of mind 



or the teacher has made a muddle of the subject. 



LESSON CXXXI. 



THE RELATION OF STONE FLOUR TO FERTILE SOIL. 



Preliminary Work. — A lesson should be given on organic and inorganic matter — 

 to distinguish between matter which was never alive and matter whicli was built 

 up by living creatures. Let the pupil begin on the objects in the schoolroom and 



36 



