80 FARM MACHINERY 



when drawn from one end. Such teeth may be spoken of 

 as adjustable. A curved knife-tooth harrow, sometimes 

 spoken of as a pulverizer, is illustrated in Fig. 51. This 



FIG. 52 A RIDING WEEUER 



crushes clods and brings the soil into uniform structure 

 very satisfactorily. The weeder has rather long teeth 

 and is an excellent implement for destroying small weeds, 

 and also to form a dust mulch and a fine tilth. The culti- 



FIG. 53 A SPRING-TOOTH LEVER HARROW 



vator tooth has the point flattened, and is curved so as 

 to penetrate the ground more readily. Often it is aided 

 in passing over obstacles by being held in place with a 

 spring. 



