394 



SCIENCE OF AGRICULTURE. 



Part II. 



2608. The SomervUle swing plough is known by its mould-board, a part of which 

 is rendered 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 

 calculated 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 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 tliis 

 inconvenience 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 

 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 the inside 

 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. 



2609. Turn-wrest swing ploughs are such as admit of removing the mould-board 

 from one side to another at the end of each furrow, for the purpose of throwing the 

 earth removed always to one side. Their principal use is in ploughing across steep 

 declivities, in order that the furrow slice may always be thrown down. Wherever it is 

 practicable, however, it is best to plough obliquely up and down such declivities ; because 

 the other practice soon renders the soil too rich and deep at bottom, and too thin and 

 poor at top. 



2610. Gray's turn-wrest swing plough (Jig. 300.) is one of the most scientific imple- 

 ments of the kind. The 

 beam, head, and sheath, must 

 always be placed in the di- '^ 

 rection of a line passing along 

 their middle ; and the two 

 handles must be placed equi- 

 distant on each side of that 

 line. There 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 (&, c, and d, a). We have already noticed (2597.) the mode in which the 

 double-moulding or earthing-up swing plough may be rendered a turn-wrest plough, of 

 a less perfect kind. 



2611. Weatherleijs moveable stilt plough {Jig. 301.) is characterised by certain joints in 

 the stilts {a a), which admit 2qj 

 of raising or lowering the 

 handles at pleasure, so as to 



suit the height of the plough- ^^i^-^ ^*^" v-- ^.^^c^-'-^ (A 



man. They also admit of ^^^*^^*-^^^;^^^I^^^\^ 



taking off the stilts for the J^ gT^ ^ 1/^ 



convenience of packing. 



These joints are the invention of Weatherley, a Northumbrian agriculturist in the 

 service of Prince Esterhazy. The plough is manufactured by Weir of London, who 

 commonly adds to it the improved draught tackle (6). 



2612. The ribbing plough is any of the above implements on a smaller scale, to be used 

 for the operation of ribbing, or laying leys or stubbles in small ridges. 



2613. Ducket's skim-coulter plough (Jig. 302.) is said to be a valuable implement, 



though not much in use. By it the 

 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 beneath, a larger 



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



