73 6 



THE POPULAR SCIENCE MONTHLY. 



kind. Nature does all things unobtrusively ; and it is only now that 

 we are beginning to see the magnitude of these secret agricultural 

 operations by which she does already all that man would wish to 

 imitate, and to which his most scientific methods are but clumsy ap- 

 proximations. 



In this great system of natural husbandry Nature uses agencies, 

 implements, and tools of many kinds. There is the disintegrating 



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frost, that great natural harrow, which bursts asunder the clods by the 

 expansion during freezing of the moisture imprisoned in their pores. 

 There is the communistic wind which scatters broadcast over the fields 

 the finer soil in clouds of summer dust. There is the rain which washes 

 the humus into the hollows, and scrapes bare the rocks for further 



