FIG. 16. Various tools adapted to tilling of fruit-plantatipns. (1) Robert's 

 form of an ideal plow; (2) vineyard and garden plow; (3) swivel plow; (4, 5) 

 subsoil plows; (6, 8) spike-tooth cultivators; (7) gang-plow; (9) spring-tooth cul- 

 tivator with side-guards; (10) an orchard gang-plow. 



(86) 



