144 



MECHANICS. 



iron. The cast-iron teeth, represented in Fig. 120, 

 are well adapted for cultivating the rows of Indian 

 corn and other hoed crops, where the soil is aheady 

 moderately mellow. For harder soils, the teeth should 

 he in the form of claws, as shown in Fig. 121, their 



Fig. 121 



Claw-toothed cultivator for hard ground. 



sharp, wedge-form points penetrating and loosening the 

 earth with comparative ease. A very efficient culti- 

 vator is made by using hoth kinds of teeth in the same 

 implement, placing the claws forward for breaking the 

 hard earth, and the broader teeth behind for stirring it. 

 Steel plates, with sharp or " duck-feet" edges screw- 

 ed at the lower extremities of the teeih. Fig. 122, are 



Fig. 122, 



useful for paring, or cutting the roots of weeds ; and 

 formed like the mould-board of a plow, they are some- 

 times used for throwing the mellow earth toward the 

 row, or, when reversed, from it. 



In all cases, the teeth should be so long and the 

 frame-work high enough above ground to allow room 



