PLOUGH. 



under circumstances always similar, as its 

 operation will necessarily be affected by the 

 weather, the state of the land, with the varying 

 depth and width of the plough, it is not an easy 

 matter to determine which form is best for 

 general purposes. It is clear that different 

 soils, as, for instance, light sand and heavy 

 clay, require mould-boards almost the frpposite^ 

 of each other; and such they are. The Nor- 

 folk mould-board is short, with rather a hollow 

 or concave surface, whilst that used in the 

 hundreds of Essex is long and convex. 



Lord Western, many years ago, improved 

 upon the form of the heavy land mould-board 

 in use in that part of the county of Essex where 

 he resides, by cutting away a considerable por- 

 tion of the lower and hinder part of the figure, 

 and by making it in a straight line lengthwise 

 from the nose to the hind part. 



Were the circumstances always the same, 

 there can be no question but that one mathe- 

 matical form of the mould-board would be pre- 

 ferable to all others ; but, under circumstances 

 so various, the plan hitherto adopted has been 

 to prove, by experience and from practical 

 operation, the forms best suited to different 

 lands under an average depth and width of 

 work, keeping as nearly as possible to the 

 principle of the wedge, as necessary for the 

 proper lifting, turning, and laying over the soil. 

 Provided the mould-board be made so that the 

 work, while in operation, goes on as it should 

 do, a good practical criterion as to its figure 

 will be found in the evidence of friction it has 

 undergone, and this, with the fine cast metal 

 now in use, can be determined to a nicety. If, 

 on a given soil, the mould-board becomes 

 brightened uniformly if the mould appears to 

 slip with light friction and with the same pres- 

 sure from one end of it to the other, it cannot 

 be far, if any thing, out of its proper shape for 

 the purpose intended. And yet, if the same 

 mould-hoard be used on some other lands, it 

 will immediately show its inapplicability to 

 them by the soil adhering to it in parts, not 

 slipping well through it, and thus evidencing a 

 want of uniformity in its general friction. 

 Therefore, considering that neither depth nor 

 width of furrow is always the same, and that 

 scarcely one circumstance affecting its use is 

 unvarying, it is difficult to find a rule which 

 shall aptly suit these changes. At the same 

 time it is not presumed that such will not or 

 cannot be found ; and the theory which most 

 accords with our view, is one which has re- 

 cently been laid down by the Rev. W. L. Rham, 

 rector of Wink-field, Berkshire, a gentleman 

 whose scientific and agricultural knowledge 

 entitles his opinion to considerable deference. 

 His theory is, that the mould-board should be 

 composed of straight lines in the direction of 

 its length, with continually increasing angles 

 to the line of the furrow : these last lines being 

 either straight, convex, or concave, horizontal 

 sections of the mould-board. 



Cooler. Simple as the coulter may appear 

 to be, it is a very important part of the plough, 

 and much depends upon its being properly 

 formed and fixed for the work it has to perform 

 in the operation of ploughing. It should be 



PLOUGH. 



[ made of iron and steel, and of sufficient sub- 

 j stance to stand firmly to the position in which 

 it is set for its work, not bending either to the 

 right hand or to the left. The blade or cutting 

 part should be about 2^ inches wide, and 

 formed by the meeting of two curves, as this 

 shape cuts the land easier than when the edge 

 is either in a straight line or curved forward. 

 TH? land side of the coulter should be flat, and 

 the opposite side a gradual taper from the edge 

 to the back: the thickness must be determined 

 by the strength of the work it has to perform. 



The angle at which the coulter is usually set, 

 is about forty-five degrees from the plane of 

 the ground ; but in summer lands it requires to 

 be placed in a more slanting position, and to 

 take the lead of the share about three-quarters 

 of an inch, to prevent the grass or rubbish 

 driving in a heap, as it otherwise might do. On 

 the contrary, when used for ploughing up hard 

 fallows, it requires to be fixed in a more up- 

 right position, and rather more backward than 

 the point of the share. It should be placed 

 about half an inch above the share, and a 

 quarter of an inch to the land side of it. Every 

 good ploughman has his own notions on the 

 subject of setting the coulter, but the above 

 directions are given from practical observation. 

 The usual mode of fixing the coulter in the 

 socket of the frame or beam, is by means of 

 wood or iron wedges driven above or below the 

 socket, or by a coarse cut screw-bolt, which 

 turns into the side of the socket and presses 

 against the coulter-stalk. Each of these modes 

 is defective, there being a complication in the 

 details of all that appears not quite adapted to 

 the class of workmen who have to use them. 



Skim Coulters. Skim coulters are sometimes 

 used for the purpose of burying the surface- 

 grass or rubbish. Sketches of two kinds are 

 given in pi. 17, m, m. The usual plan is to fix 

 the skim about six inches before the common 

 coulter. 



Wheel Coulters are used in the fen lands, and 

 are useful when ploughing up turf. One of 

 these coulters is represented in pi. 17, n. The 

 cutting-disk should be made of steel, with a 

 nave sufficiently long for it to be steady, and 

 the box should be bored true, and revolve on a 

 well-fitted steel pin, as on the perfect fitting of 

 the box and axle the correct working of the 

 disk, and consequently the effective operation 

 of the plough, depends. 



Siring Ploughs. The advantages attributed 

 by Mr. Ransome to the swing plough are as 

 follows : 



1. It admits of being set into its work at a 

 given depth, either shallower or deeper, by the 

 alteration of the draught iron at the point of 



! draught, or by increasing or decreasing the 

 I distance at which the power of the horses is 

 j applied. 



2. The ploughman has also the power of re- 

 j gulating, in some degree, the depth of the work, 



by either lifting or bearing upon the handles. 



3. It is a plough of more simple construc- 

 tion than any other, and less expensive in its 

 first cost. 



4. A skilful workman can plough across 

 ridge and furrow at very nearly a uniform 



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