16 
BULLETIN 320, U. S. DEPARTMENT OF AGRICULTURE. 
Pig. 8. — A spike-tooth harrow, an implement Fig. 9. — A disk harrow, an implement ex- 
in general use to prepare the seed bed, tensively used for preparing the seed bed. 
after plowing, for corn. after plowing, for corn. 
Fig. 10. — A spring-tooth harrow, used exten- Fig. 11. — An acme harrow, an implement 
sively in Michigan, Pennsylvania, and especially adapted for thoroughly pul- 
New Jersey in preparing the seed bed, verizing the seed bed for corn. The 
after plowing, for corn. evener is attached at A. 
Fig. 12. — A spring-tooth harrow, showing its use in preparing sandy-loam land, after 
plowing, for corn. 
