300 



Ploughs and Ploughing. 



feature indeed ; and a large slice of soil (sometimes the greater 

 part of the surface of the furrow-slice, carrying the surface 

 rubbish with it) is pared off and turned over into the bottom of 

 the furrow. By this means there is less soil to be moved by the 

 breast, while the complete burial of all grass, stubble, weeds, 

 &c., conduces very much to keeping the land clean and to 

 making a tilthy seed-bed. The writer once had some land 

 ploughed with skims on the ploughs, and part of the same field 

 (stubble land) ploughed without skims ; the skimmed land 

 showed up clean and bare after harvest, the unskimmed was so 

 foul that it required to be immediately bare-fallowed. 



It is a curious fact that the draught of the plough is not 

 altered in the least by the presence or absence of a coulter. 

 Its use is simply to cut the edge a little more cleanly than the 

 front edge of the mouldboard would do, and it is almost un- 

 necessary where a skim-coulter is in use. Indeed, in many of 

 the American forms used on the prairies for ploughing the clean, 

 loose, stubble soil, no coulter of any kind is used at all, the 

 cutting edge of the breast being quite effective ; but still, on 

 some of our stiffer soils here, it is useful in giving a shape to the 

 slice and a guide to the body of the plough. On such soils, if 

 none is used, or if it is improperly set, the plough does not 

 run so true or so steadily. Still, the fact remains that on most 

 soils where a good slice is pared off the edge by the skim- 

 coulter there is no need at all for the knife-coulter, especially on 

 stubble land. 



The disc- or wheel-coulter has not been a universal success for 

 several reasons. It, of course, runs with less friction through the 

 soil than does a knife- or skim-coulter ; it does not gather any 

 weed or dung rubbish on its edge as it runs along, and is there- 

 fore valuable for ploughing in surface dressings ; but, on the 

 other hand, it will not work on stony land, while it cannot be 

 set so accurately as the knife-coulter — a matter of extreme 

 importance in the case of swing-ploughs, where the least change 

 in the set of the irons makes all the difference between easy, 

 good work and the reverse. In a homogeneous soil, however, 

 and with a wheel plough, these drawbacks disappear, but still 

 the wheel-coulter can never take the place for efficiency of work 

 of the skim. A new style of disc-coulter is now becoming 



