390 SCIENCE OF AGRICULTURE. Part II. 



implement we shall adopt the latter term, because the unimproved Scotch plough differs 

 little from some old forms of the implement common to Europe from the time of the 

 Romans. As the operation of ploughing, like many other operations in practical 

 husbandry, must often vary in the manner of its being performed, it is evident that no 

 one particular sort of plough can be superior to all others, in every season, and under 

 every variety of soil or inclination of surface. The Scotch plough, however, and the 

 variations of which it is susceptible, render it by far the most universal tillage imple- 

 ment hitherto invented or used. 



2587. Ploughs are of two kinds : those fitted up with wheels, and called wheel ploughs ; 

 and those without wheels, called swing ploughs. The latter are the lightest of draught, but 

 require an experienced and attentive ploughman to use them ; the former work with greater 

 steadiness, and require much less skill in the manager: some sorts, indeed, do not require 

 holdin"- at all, excepting at entering in, and turning on and off the work at the ends of 

 the ridges. On the whole, taking ploughmen as they are, and ploughs as they are gene- 

 rally constructed, it will be found, that a district ploughed with wheel ploughs will show 

 greater neatness of work than one ploughed with swing ploughs : but, on the other hand, 

 taking a district where the improved form of swing ploughs is generally adopted, the 

 ploughmen will be found superior workmen, and the work performed in a better manner, 

 and with less expense of labour, than in the case of wheel ploughs. Northumberland in 

 this respect may be compared with Warw ickshire. 



2588. In the construction of ploughs, whatever be the sort used, there are a few gene- 

 ral principles that ought invariably to be attended to ; such as the giving the throat and 

 breast, or that part which enters, perforates, and breaks up the ground, that sort of long, 

 narrow, clean, tapering, sharpened form that affords the least resistance in passing 

 through the land ; and to the mould-board, that kind of hollowed-out and twisted form, 

 which not only tends to lessen friction, but also to contribute greatly to the perfect turn- 

 ing over of the furrow-slice. The beam and muzzle should likewise be so contrived, as 

 that the moving power, or team, may be attached in the most advantageous line of draught. 

 This is particularly necessary where a number of animals are employed together, in order 

 that the draught of the whole may coincide. 



2589. The construction of an improved Scotch suing plough is thus given mathemati- 

 cally by Bailey of Chillingham, in his Essay on the Construction of the Plough on Ma- 

 thematical Principles, 1795. It had been previously aimed at by Small of Berwickshire, 

 and subsequently by Vetch of Inchbonney, near Jedburgh, {Highland Soc. Trans, vol. iv. 

 p. 243.), and more recently and completely in the Quarterly Journal of Agriculture for 

 February, 1829. Whoever wishes thoroughly to understand the construction of the 

 plough, and the principles of its operation, are recommended to the last-mentioned very 

 excellent paper, which is too long to be given here, and which would lose half its value 

 by being abridged. 



2590. Land, when properly ploughed, Bailey observes, must be removed from a hori- 

 zontal 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. 



2591. 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 weight of the 

 draught, and to turn over the furrow, and leave it in its proper position, without tearing 

 or breaking it. 



2592. To have the line of draught at right angles to the horses' shoulders is of great 

 iinportance in the formation of a plough ; a circumstance of which the greatest part of 

 the plough-makers are totally ignorant, although it is well known to every one that has 

 the least knowledge of mechanics. If we take the angle that the horses' 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. 



2593. Length of beam. If the plough be properly made, 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. 



2594. Left 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 part of the 

 mould-board to press hard against the furrow, and crush and break it, besides increasing 

 the labour of the cattle. 



2595. The position of the coulter must not deviate much from an angle of 45 degrees: 



