Line of Draught of Plows. 



181 



Jiuviiio; a socket on its face, which secures the shank of the 

 coulter; is made to revolve by the action of a screw, thus 

 cnahling the plowman to set it at any desired angle. 



The favorite plans for raising or lowering the coulter in Eng- 

 land are given in Fig. 89, and also for changing its angle, which 

 will be readily understood on inspection. 



JF'iff. 89, 



Fig. 90 represents the lock coulter, which is made of wrought 

 iron, steel edged. It passes through the plow beam, and is made fast 

 on top with a key, or with a nut and screw, and locks through the 

 share and mould-board where they join together. 

 The adjustment is a very 

 strong one, both for the 

 coulter and the plow, and 

 fits the implement for work- 

 ing among stones, stumps 

 and roots, as the coulter 

 cannot be turned out of' 

 place or broken by such 

 obstacles. The revolving 

 coulter is represented in Fig. 91. It consists of a steel plate, 

 revolving on an axis, and having a stem which is clasped to the 

 beam, as shown in the cut. In some cases the coulter is con- 

 veniently replaced by the fin share represented in Fig. 92. It is 

 used for plowing sod lands infested with roots and stumps or 

 stones, where the sward cutter cannot be used without danger of 

 getting bent or misplaced. It is also useful when plowing in 

 stubble or coarse manure, serving to keep the plow from clogging 

 at the standard. It separates the furrow slice from the unplowed 

 land easier and more smoothly than it could be done by the 

 breast of the plow. Much depends upon the form and size of 



jFlff. 90. 



JPig. 97. 



