208 



AGRICULTURAL ENGINEERING 



level, is worthy of consideration. In Europe, the reversible 

 plow has been in more extended use than in this country. 



The moldboard type of reversible plow consists of two 

 plow bottoms, a right- and a left-hand, which are used alter- 

 nately. These plows do not have many of the conveniences 

 of the high-lift sulky and do not possess the usual provisions 

 for relieving the landside friction by placing the load on the 

 carriage. It is, however, an entirely practical tool. The 

 reversible disk plow is so arranged that by swinging the team 

 and hitch about to the opposite direction, the inclination of 

 the disk is changed, but the carriage is left unchanged and 

 is simply drawn across the field in the reverse direction. It 

 would seem that this implement has reached a higher state 

 of development than its moldboard mate. 



Tractor Gang Plows. The use of the tractor for plow- 

 ing requires for the best service special plows adapted to 



Fig. 118. An engine gang plow. 



the special requirements of tractor power. Tractor gang 

 plows are made with moldboard and disk plows and range 

 in size from two to fourteen furrows. 



In general there are two types, one the flexible beam 

 shown in Figure 118, in which each plow or pair of plows 

 may be handled independently, and the rigid beam, Fig. 118a, 



