ESSENTIAL PARTS OF A PLOUGH. 17 



It is necessary, however, to vary this part of the 

 plough, according to the nature of the soil it is intended 

 for, so that no general rule can be laid down for its for- 

 mation. In some countries, a short mould-board with 

 a concave surface is the most useful ; in others, a long 

 and convex form is preferred. A mould-board which 

 in one description of soil will slide along with an equal 

 pressure, and without getting clogged with earth, in 

 another will work much less freely, and will soon show 

 by the adhesion of the soil that it is unfit for that par- 

 ticular description of land ; therefore, every farmer has 

 to act upon his own experience in the matter, and to 

 suit the mould-board to the work he has for it to do. 



\\hen the share and the mould-board are fixed- in 

 their places on the frame, the plough-body is complete 

 and has the following appearance : 



THE PLOUGH-BODY. 



To the fore-part of this plough-body is attached the 

 beam, which extends in a forward direction, and is 

 finished at the end by what is called the plough- 

 head, a contrivance for regulating the depth of the 

 plough, and the line of draught. The beam may 

 differ in strength according to the quality of the work 

 to be performed, but it need never greatly vary in 

 length ; about three feet is considered a good length 

 c 



