374 SCIENCE OF AGRICULTURE. Part II. 



Princples, 1196. It had been previously aimed at by Small of Bertvick shire, and subse- 

 quently by Vetch of Inchbonney, near Jedburgh. (Highland Soc. Trans, vol. iv. p. 243.) 



8483. Land, when properly ploughed, Bailey observes, must be removed from a horizontal position, 

 and twisted over to a certain angle, so that it may be left in that inclining state, one furrow leaning upon 

 another, till the whole field be completely ploughed. The depth and width of the furrows which is most 

 approved of by farmers, and commonly to be met with in the best ploughed fields, are in the proportion of 

 two to three ; or, if the furrow be two deep, it must be three wide, and left at an angle of 45 to 46 

 degrees. 



2484. Various forms have been given to the different parts of the plough, by ingenious persons, according 

 to their different fancies, in order to diminish the weignt of the draught, and to turn over the furrow, and 

 leave it in its proper position, without tearing or breaking it 



2485. To have the line qf draught at right angles to the horse's shoulders, is of great importance in the 

 formation of a plough, a circumstance of which the greatest part of the plough-makers are totally igno- 

 rant, although it is well known to everj? one that has the least knowledge of mechanics. If we take the 

 angle that the horse's shoulders make with a perpendicular from the horizon, and continue'another line at 

 right angles to it, or parallel to the draught chain ; the length of this line from the horse's shoulders to 

 where it meets or crosses the coulter, at half the depth of the furrow, will be thirteen feet two inches for 

 ordinary sized horses. 



2486. Length of beam. If the plough be properly m,ade, the line of draught should pass through the 

 middle hole of the plough bridle at the point of the beam. This requires the beam to be seven feet long, 

 to give it a proper height at the bridle. 



2487. Lf^fl side plane. That part of the plough next the solid land, should be made a perfect plane, and 

 run parallel to the line of draught; whereas some of the common ploughs are completely twisted in that 

 part, and deviate more than two inches from the line of draught ; this throws the plough to the left, and 

 causes the hinder i)art of the mould-board to press hard against the furrow, and crush and break it, besides 

 increasing the labor of the cattle. 



24^. TTie position of the coulter must not deviate much from an angle of 45 degrees ; for, if we make it 

 more oblique, it causes the plough to choke up with stubble and grass roots, by throwing them up against 

 the beam ; and, if less oblique, it is apt to drive the stones or other obstacles before it, and make it heavier 

 to draw. 



2489. Of smng ploughs, the best, is the implement known in England as tlie Scotch 

 jilough. It is almost the only plough used in Scotland, and throughout a considerable 

 part of England ; it is dravv^n with less power than wheel ploughs, the friction not being 

 so great ; and it probably admits of greater variations in regard to the breadth and 

 depth of the furrow-slice. It is usually drawn by two horses abreast in common til- 

 lage ; but for ploughing between the rows of the drill culture, a smaller one drawn by 

 one horse, is commonly employed. A plough of this kind, having a mould-board on 

 each side, is also used both in forming narrow ridges for turnips and potatoes, and in 

 laying up the earth to the roots of the plants, after the intervals have been cleaned and 

 pulverised by the horse and hand-hoe. This plough is sometimes made in such a manner, 

 that the mould-board may be shifted from one side to the other when working on hilly 

 grounds ; by which means the furrows are all laid in the same direction ; a mode of 

 construction as old as the days of Fitzherbert, who wrote before the middle of the six- 

 teenth century. This is called a turn-wrest plough. 



2490. Swing-ploughs, similar to the Scotch plough, have been long known in Eng- 

 land. In Blythe's Improver Improved (edit. 1652), we have engravings of several 

 ploughs ; and what he calls the " plain plough," does not seem to differ much in its 

 principal parts from the one now in use. Amos, in an Essay on Agricultural Machines, 

 says, that a person named Lummis (whom he is mistaken in calling a Scotchman, see 

 Maxwell's Practical Husbandman, p. 191.) " first attempted its construction upon 

 mathematical principles, which he learned in Holland ; but having obtained a patent for 

 the making and vending of this plough, he witliheld the knowledge of these principles 

 from the public. However, one Pashley, plough-wright to Sir Charles Turner of Kirk- 

 lea;them, having a knowledge of those principles, constructed upon them a vast number 

 of ploughs. Afterwards his son established a manufactory for the making of them at 

 Rotherham. Hence they obtained the name of the Rotherham plough ; but in Scotland 

 they were called' the Dutch or patent plough." " At length the Americans, having ob- 

 tained a knowledge of those principles, either from Britain or Holland, claimed the 

 priority of the invention ; in consequence of which, President Jefferson, of the United 

 States, presented the principles for the construction of a mould-board, first to the Insti- 

 tute of France, and next to the Board of Agriculture in England, as a wonderful disco- 

 very in mathematics." {Communications to the Board of Agriculture, vol. vi. p. 437.) 

 According to another writer, the Rotherham plough was first constructed in Yorkshire, 

 in 1720, about ten years before Lummis's improvements. [Survey of the West Hiding of 

 Yorkshire. Sup. Encyc. Brit. art. Agr.) 



2491. The present imjyroved swing plough (fg. 111., p. 127.), was little known in 

 Scotland till about the year 1764, when Small's method of constructing it began to excite 

 attention. {SmaWs Treatise on Ploughs and Wheel Carriages, 1784;' and Lord JTaimes^s 

 Gentleman Farmer. ) This ingenious mechanic formed the mould-board upon distinct 

 and intelligible principles, and afterwards made it of cast-iron. His appendage of a chain 

 has been since laid aside. It has been disputed, whether he took the Rotherham, or the 

 old Scotch plough for the basis of his improvements. The swing plough has been since 

 varied a little, in some parts of Scotland, from Small's form, for the purpose of adapting 



