476 



ENGINEERING ON THE FARM 



when worn without buying a new wheel. To decrease the 

 draft of such implements as have wheels, the tires should 

 be broad and concave and the wheels high. Some bearings, 

 such as those of the pitman of a mowing machine or the 

 disks of a harrow, are subject to thrust or side pushing 

 and they should be bearings adjustable to wear. 



Table, Compiled from a Large Number of Experiments 

 Showing the Number of Feet and Seconds Required 

 to Turn Farm Implements 



Care of machines. When a new machine is started, 

 extra attention should be given to the bearings for two or 

 three days. If they heat, they are too tight, dirty, or not 

 properly lubricated. Care should be taken that in no case 

 a bearing or gear runs dry. Knives and cutters intended 

 to have a keen edge should be kept sharp and be replaced 

 when worn or broken. The manufacturer's instructions for 

 operating and oiling an implement should be carefully 



