HARROWING AND ROLLING \Qj 



action of the roller and the rain is to make so thick 

 a crust that many of the seeds will not be able to 

 force their way through it or will be smothered by 

 poor ventilation. After the grain is up the rolling- 

 may be done to advantage, as it then makes a firm 

 soil about the roots of the plants, a condition of 

 benefit to grain crops. 



The most simple form of roller is a solid or hol- 

 low cylinder of wood fastened into a frame by which 

 it is drawn. Some rollers have spikes or blunt at- 

 tachments fastened to their surfaces for breaking 

 clods. A roller that is quite popular consists of a 

 cylinder of pressed steel. 



