CLOD-CRUSHERS, 151 



consists of about two dozen circular cast-iron disks, 

 placed loosely upon an axle, so as to revolve separately. 

 Their outer circumference is formed into teeth, which 

 crush and grind up the clods as they roll over the surface 

 of the field. Every alternate disk has a larger hole for 

 the axle, which causes it to rise and fall while turning 

 over, and thus prevent the disks from clogging. Fig. 162 

 represents this implement, as modified and manufactured 

 in this country. It is used only where heavy clay soils 

 prevail. 



This clod-crusher can bo used only where the ground 

 and the clods have become quite dry. Even then it packs 



Fig. 162. 



American Chd-cru^her. 

 the soil, and if followed by a harrow, with scarifier teeth, 

 to loosen it again, it would prove an advantage. It is 

 only in certain seasons that it is most successfully em- 

 ployed, or when quite dry weather follows a wet spring. 

 As thorough tile-draining is generally adopted, it becomes 

 less necessary. 



The best clod-crushers are sold for about $125. 



THE ROLLER, 



This implement, now in general use, is employed for 

 pressing in grass seed after sowing, for smoothing the sur- 

 face of new meadows early in spring, and for other similar 



