ELEMENTARY FORESTRY 



385 



In connection with geography lessons trace the journey 

 of the soil that is being carried from the district, until it 

 reaches the ocean. Has the teacher or have members of 

 the class visited any of the cities along the route and 



FIG. 155. TENEMENT HOUSES MADE BEAUTIFUL 

 (Photograph by Louis P. Nash, Holyoke, Mass.) 



observed the working of dredges in deepening the chan- 

 nels and cleaning the mud out of the harbors ? Many 

 millions of dollars are expended annually in river and 

 harbor improvements, much of which might be saved by 

 keeping the soil at home. 



Now follow this material back into the fields and hills, 

 where the forest has been recently cleared away, and 

 where the ground is bare and has been washing badly. 

 Show how, after the lighter constituents of the soil have 

 been washed away, the sand and gravel are taken up and 

 carried over the fertile ground below. Compare the way 



