122 FARM MACHINERY 



and made to revolve by pawls which act by opening and 

 closing the planter. 



167. The modern planter. Although most planters are 

 called upon to do about the same work, they differ much 

 in construction. The essentials of a good, successful 



FIG. 89 A MODERN CORN PLANTER WITH LONG CURVED FURROW OPENERS, 

 VERTICAL CHECK HEAD, AND OPEN WHEELS 



planter have been set forth as follows: (i) It must be 

 accurate in dropping at all times ; (2) plant at a uniform 

 depth ; (3) cover the seed properly ; (4) convenient and 

 durable; and (5) simple in construction. 



168. Drops. The early planters had slides or plates in 

 which holes or seed cells were provided which were large 

 enough to hold a sufficient number of kernels to make 

 an entire hill of corn. Planters are constructed in this 



