136 



MECHANICS. 



THE SUBSOIL PLOW, 



represented in Fig. Ill , consists of a narrow, horizon- 



Fig. 111. 



Subsoil plow. 



tal, wedge-like share for loosening the earth, and con- 

 nected with the beam by a strong plate of metal run- 

 ning edgewise, so as to cause little resistance through 

 the soil. This plow follows in the furrow after a com- 

 mon plow, loosenmg but not lifting out the earth. The 

 operation is shown in Fig. 112. The benefit of sub- 



Subsoil plowing in the furrow of a common plow. 



soiling will last three or four years ; but it is of gi-eat 

 importance that land be well underdrained, for if the 

 earth becomes heavily soaked with water, it settles 

 down into one compact mass, and the advantages of 

 the operation are lost. 



fowler's draining plow. 



The mole-plow, for forming a small hollow passage 

 beneath the soil, by means of a sharp iron plug forced 

 through it at the lower end of a thin coulter, has been 



