142 Practical Farming 



fashioned are almost innumerable, but of late years the 

 attention of inventors has been toward other forms not 

 dependent on straight spikes for their work. One of the 

 best of the modem harrows is the spring-tooth harrow, 

 in which the teeth are curved steel springs with pointed 

 teeth. These do excellent work in ground where there 

 is no sod or rough matter turned under, as they tear 

 and cultivate the soil very thoroughly. 



Then came the harrow known as the Acme, which con- 

 sists of a long row of small moldboards attached to a com- 

 mon bar, which merely turn and pulverize the surface 

 without dragging anything out. This is an excellent 

 implement for fining the surface over a buried sod. 



But for deeper cutting the disk principle was adapted 

 to the harrow, and the disk harrow came into use. The 

 deep cutting of the disks gave them an advantage, while 

 they, too, have no tendency to pull out buried trash. 

 Finally a modification of the disk came into use, known 

 as the cutaway, from the fact that the outer perimeter of 

 the disks are cut into teeth. This form cuts still deeper 

 than the disk and both are the last development of soil- 

 preparing implements. 



