134 



Report on Tbials of Plows. 



the fertile straciiin, and 



as wide as th.e trench, as 



^^ represented at C. The 



1 next step is to raise a 



; slice of the subsoil of any 



S=j^,--^j^ ;==^-==^ thickness required, not 



I^iff. 6. 



making greater depth 

 than twenty-one inches, 

 as shown at D. The dart 

 marked eighteen inches, 

 by error, should be 21. 

 The representation in Fig. 

 5 is of Avork done in ad- 

 hesive loam, and shows 

 ^^^' '^* rather the working of the 



jilow than the exact appearance of the trench, that never being 

 quite so clear and square after the passage of the plow, as is here 

 represented. 



In very unadhesive, gravelly or sandy soils the appearance will 

 be as represented in Fig. 6. Debris, as at H, occurs in gravels, 

 consisting in part of the falling of the edge of the land side bank, 

 and in part of the falling back of the subsoil slice. This is often 

 in about the proportions required, and then only the passage of 

 the transformed, with its peculiar grinding action is required to 

 perfect the operation. If a larger admixture of the surface soil 

 is required at the bottom of the trench, a small slice of it is easily 

 thrown down by a small plow drawn by one horse before the 

 passage of the transformed. 



It is, of course, impossible to leave as clean a furrow as is rep- 

 resented in Fig. 7, as the ground from both sides will fall in and 

 fill the furrow. It is rather intended to represent the actual 

 working of the plow at the depth of two feet. These plows are 

 worked with two pairs of strong oxen. 



