TILLAGE MACHINERY 



2. Spring-tooth harrows. 



3. Curved \cnife-tooth harrows or pulverizers. 



4. Disk harrows: Full disk; cutaway; spading; orchard. 



79 



It will not be possible to illustrate all these forms of 

 harrows. The common smoothing harrow is not shown, 



FIG. 50 A WOOD-BAR LEVER SMOOTHING HARROW. A CHEAPER HARROW 

 IS MADE WITH FIXED TEETH AND A WOODEN FRAME 



but a lever harrow with wooden bars is shown in Fig. 50. 

 Wooden-frame harrows can be used to better advantage 

 in trashy ground when they are provided with a tooth 

 fastener so arranged that the teeth will slope backward 



. 51 A CURVED KNIFE-TOOTH HARROW OR PULVERIZER 



