118 



On Affrictiltural Meclianics. 



[Rliomboiiial Harrows.] 



In many districts the harrow is used not merely to reduce the sur- 

 face of ploughed land by tearing down the lip of the furrow, but to stir 

 and lift the furrow-slice to its whole depth. This is not the proper 

 office of the harrow ; it should be done by the grubber. The use of 

 heavy drags for this purpose, and the application of great power to work 

 them (I have frequently seen teams of six and eight oxen drawing a 

 single heavy harrow or drag), cannot be economical ; it v/ould be much 

 cheaper to use an implement for the purpose manageable by two horses. 

 The grubber, or cultivator, presently to be described, is such an imple- 

 ment. 



Though, liowever, the harrow should not be employed to stir the 

 whole depth of the furrow, it should stir it ■perfectly to the depth to 

 v/hich it goes, and for this purpose it is well to give the teeth a slight 

 inclination forwards, that they may have a sufficient hold of the ground. 

 Their length should be just the depth to which they are intended to go 

 (4 or 5 inches is sufficiently long), and they should not be fastened in 

 by being riveted into a plate of iron screwed on to the beams of the 

 harrows; but they should be slightly of a wedge-shape, that, whenever 

 they get loose, they may be fixed by merely driving them in with a 

 hammer. The tines should, for this purpose, project somewhat above 

 the beam or spar through which they pass ; and thus, when the work- 

 ing part becomes worn, it may be lengthened by driving them far- 

 ther in. 



There is another advantage in having the tines of the harrow short: 

 the surface of the land is much more perfectly reduced by it when the 

 frame-work actually lies and rubs along the ground, than when it rests 

 on twenty or thirty long tines, as it does in the long-toothed drags. 

 The implement thus combines the properties both of a roller and a 

 harrow. 



The rhomboidal form of the harrows, which ensures that the teeth 

 shall all proceed in different paths, is the best form for all the three 

 purposes to which the implement is applied. It is best for reducing a 

 rough surface, for gathering and shaking out weeds, and it is best for 

 covering the seeds. For the latter purpose a lighter harrow with a 

 greater number of teeth may be used, for the land is generally reduced 



