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CHAPTER VIII 



Turn, or Mould-Board Ploughs. Turn, or mould-board ploughs are so 

 called because they cut from the soil a clean slice and turn it over top side 

 down, through the action of the mould-board ; the single mould-board 

 plough is shown in Fig. 27 ; a is the share, b the landslide, c the coulter, 



FIG. 29 



and d the mould-board or breast. The coulter shown is of the knife type ; 

 it may be replaced by a rolling coulter, consisting of a revolving steel disc, 

 and, instead of being hung from the beam, it may be bolted on to the share 

 or may be entirely absent. This type of plough is the instrument that is 

 almost always used in the preparation of land for planting crops of any kind ; 



FIG. 



the plough may be a single unit, or there may be a number of units forming 

 a gang plough. The double mould-board plough is shown in Fig. 28, the 

 lettering being as for the single mould-board plough. This plough throws a 

 slice of earth on either side of the share, and finds an extended use in the 



