Book IV. 



SWING PLOUGHS. 



375 



it more completely to particular situations and circumstances. Of late this plough lias 

 been made entirely of iron. In Northumberland the mould-board is made less concave 

 than in Berwickshire, and in Berwickshire it is even less concave than Small's plough. 

 Different degrees of concavity in the mould -board suit different soils : soft and sandy 

 soil requires most, and a loamy or clayey soil least concavity. 



2492. The Somerville plough is known by its mould-board, apart of which is ren- 

 dered moveable by hinges ; the advantage of this is, that the furrow can be laid more 

 or less flat at pleasure. " Mould-boards," Lord Somerville observes, " formed to lay 

 furrows in ley, so as to give the most soil to harrows, cannot be of that form best calcu- 

 lated to make good work in stirring earths, more especially the last, which ought to be 

 thrown up in small seams, as it were, that the seed may be duly buried. It has hitherto 

 been held necessary to rip off the plate for this purpose, and drive in wedges, by which 

 the mould plate must be injured. From the trouble attending this operation, it has 

 generally been omitted, and the land, of course, imperfectly worked. But this incon- 

 venience may be remedied, and the mould-board be adjusted with great facility and 

 expedition, by the following means : When the mould-board is formed, and its plate 

 fitted as usual, let the hind part be cut off, and again connected with the fixed part of 

 the mould-board by means of flat hinges, or of thin flexible plates of tempered steel, or 

 of hard hammered iron, so as to admit of that part being set to have different inclinations 

 with the fixed part of the mould-board : by means of a screw passing from tlie insidfe 

 through the lower parts of the handle of the plough, opposite the back of this moveable 

 piece, the screw may be made to keep it at any desired degree of inclination, according 

 to the nature of the work to be performed. This plough, however, has been but little 

 used, and does not seem to meet the approbation of the best cultivators. 



2493. The tum-wresi swing plough {Jig. 284.), is very useful for working on the side 



of steep hills, or in a dia- 

 gonal direction, where the 

 furrow-slice may be turned 

 to the lower side. The 

 labor, both to men and cattle, 

 is greatly increased, when 

 ploughing steep grounds, 

 straight up hill. In some 

 cases, where the declivity is 



great, a furrow can only be taken down hill, which is a very tedious operation ; whereas 

 a plough of this form, in which the mould-boards are easily shifted to any side, may be 

 employed with less labor to the cattle, and with greater expedition ; because the plough- 

 man, having it in his power to turn the earth of the furrow-slice either to the right or left 

 hand, according as it answers his purpose, can always turn it to the lower side, where 

 he is ploughing in a diagonal direction, or straight along the side of a steep hill. The 

 form of this plough is somewhat different from that of the common plough, and may be made 

 in different ways. But the beam, head, and sheath must always be placed in the direc- 

 tion of a line passing' along their middle ; and the two handles must be placed equi- 

 distant on each side of that line. Tliere are two mould-boards and two coulters, and a 

 mould-board is produced on either side, at pleasure, by moving the lever (a) between the 

 plough handles from the one side to the other. The line of draught can be shifted with 

 equal ease and expedition, and at the same time one of the coulters raised up clear of the 

 land, and placed along the side of the beam, whilst the other is put down, and placed 

 in a proper position for cutting off the furrow-slice from the furrow ground. All this is 

 performed at once, without the ploughman's changing his position, by means of two 

 levers (6, c, and d, a). In short, this is one of the best of implements of its kind, and 

 where the use of a turn-wrest plough is recommendable, no other variety will be found 

 to equal it. We have already noticed (2489.) the mode in which the double moulding 

 or earthing-up swing plough, may be rendered a turn-wrest plough, of a less perfect 

 kind. 



2494. Ducket's s/dm coulter plough (Jig. 285.), is considered a valuable implement, 

 though not much in use. By it the *~^=:;i2;;-;^^^ 285 



ground may be opened to any depth 

 in separate horizontal portions of 

 earth; and as the weeds or grassy 

 surface are turned down in the first 

 operation, and covered by fresh earth 

 or mould from beneatli, a larger 

 proportion of nourishment is supposed to be provided for the crop, while at the same 

 lime it is rendered more clean, and the inconvenience of the roots of the grasses or other 

 plants wholly got rid of. It requires a strong team in the heavier sorts of soil, but this 



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