CHAPTER XIV 

 ON THE EXAMINATION OF SOILS 



SURFACE accumulations of decaying leaves 

 should be removed and a slice of uniform thick- 

 ness from the surface to the desired depth should 

 be secured. To eliminate the effects of accidental 

 variations in the soil, select specimens from five 

 or six places in the field and remove several 

 pounds of the soil to the depth of six inches, or to 

 the change between the surface soil and the sub- 

 soil, in case such change occurs between the 

 depth of six and twelve inches. In no case is 

 the sample to be secured to a greater depth than 

 twelve inches. If the surface soil extend to a 

 greater depth, a separate sample below the depth 

 of 12 inches is to be obtained. If the surface 

 soil extend to a depth of less than 6 inches, and 

 the difference between it and the subsoil is 

 usually great, a separate sample of the surface 

 soil should be secured, besides the one to the 

 depth of six inches. 



The depth to which the sample of subsoil 

 should extend will depend on circumstances. 

 It is always necessary to know what constitutes 

 the foundation of a soil, to the depth of three 

 feet at least, since the question of drainage, 



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