132 



FARM MACHINERY 



unless the corn be of uniform size and a seed plate chosen 

 to suit the size of corn. Types of corn vary much in size 

 of kernel, and one plate will not suit all types and varie- 

 ties. Makers usually furnish several plates with their 

 machines, and others may be secured if necessary. It 

 stands to reason that no planter can do good work unless 

 these conditions are fulfilled. The planter should be cali- 

 brated and tested before taken to the field, if accuracy of 

 work is desired. 



181. Corn drills. Although most planters may be set 

 to drill corn, the corn drill remains a distinct tool and is 



FIG. 98 THE SINGLE-ROW CORN DRILL 



used to a large extent in certain localities of the country. 

 Fig. 98 shows a single-row drill which differs but little 

 from others except that an extra knife is provided in front 

 of the seed tube. Various covering devices in the way of 

 shovels and disks are provided. Drills are now made to 

 take two rows, and even four, when made as an attach- 

 ment to a grain drill. 



182. Listers. The use of the lister is confined to the 

 semi-arid regions. It can be used in most of the corn- 

 growing sections where the rainfall is not overabundant. 



