In Fig. 5 is represented an improved form of plough, made by the Ames Plough Co. A is the frame; B B are the handles by which the operator guides the plough ; C is the gauge-wheel, which runs upon the surface of the soil and determines by the distance between its perimeter at the bottom and the bottom of the ploughshare the depth of the furrow; D is the coulter which severs the furrow- slice from the land in advance of the share ; E is the mould-board, and F is the clevis to which the draught is applied. The manner in which the furrow is turned by the plough is of considerable importance. Greensward land may be ploughed with the furrows turned completely over so as to kill the herbage, as shown in Fig. 6; or it may be Lap-furrowed, as shown in Fig. 7. The difference is, that in the former case the ploughed land lies solid, and is difficult to break up, whereas in the latter the land will break somewhat of itself, while there will remain at the same time beneath the furrows the hollow triangular

spaces shown in Fig. 7. Hence, when cultivator, or clod-crusher, is passed over the land, the soil will be more thoroughly broken up. In arable land-that is, land that has been well ploughed before, and is not of a very clayey nature-the furrows may be turned completely over with such a short turn that the twisting of the soil itself will cause it to break up, as shown in Fig. 8. Still another kind of ploughing is

performed by the double Michigan plough, the furrows of which are shown in Fig. 9. The upper furrow merely skims or pares off the upper portion of the sod and inverts it in the bottom of the furrow-a trench left by the bottom plough in its previous traverse. By this method the soil is well broken up. The ploughing may be deep, and the roots of grass, weeds, etc., are thoroughly buried.

The amount of twist given to the furrow is determined by the form of the mould-board. All other things being equal, a long twist will require the least power to draw, while a short one will more thoroughly break up the soil. The manner in which the furrows will lie depends upon the angle at which the cutter or coulter is set. Thus in Fig. 10 the cutter, being set at an angle as shown, is proper for ploughing flat furrow-slices, and stands as much inclined toward the mould-board side as the land-side (as the side of the plough next to the unploughed land is termed) does, and it is generally considered best to incline it even a little more, in order to obtain that beveled edge of the furrow-slices so essential to their sure and finished matching, side by side, as they come from the plough, and to do perfectly flat work.

In Fig. 11 B and C are the furrows, and the dotted lines denote the direction in which the furrow B will fall, D being the mould.



In order to plough lap-furrowed slices, the cutter or coulter is adjusted as shown in Fig. 12, in which A represents the land-side, or unploughed land, B the coulter or cutter, C the mould, and D, E, and F the furrows already turned. The forward inclination of the coulter or cutter may be made greater or less, but it is always set with the point in advance. In some cases a circular cutter takes the place of the knife-coulter, because it will sever fibrous roots the more readily. The width of the furrow depends upon the position of the plough with reference to the line of draught of the horses, and is usually adjusted through the medium of either the draughtrod or of the clevis, and examples of each of these methods will be found in our illustrations. To illustrate the influence of the line of draught upon the plough, however, let B in Fig. 13 represent the forward
end of the plough-beam, and c the centre of resistance on the plough, which may be assumed at two inches above the plane of the base of the plough, d e, though it is liable to constant changes, from the depth of the furrows and constant inequalities in the soil.

We have first to consider the particular form of those parts through which the motive power is brought to bear upon the plough. It is evident that the motive force acts in a direct line from the hook or ring at the shoulder of the animal, to the centre of resistance, and a Straight bar or beam, lying in the direction c b, and attached firmly to the body at c, would answer all the purposes of draught, perhaps better than the present beam, but for considerations of convenience. The draught, however, not being the end in view, but merely the means by which the end is accomplished, the former is made to subserve the latter; and, as the beam, if placed in the direct line c, to b, would obstruct the proper working of the plough, we are compelled to resort to an indirect action to obtain the desired effect. This indirect action is accomplished by means of an angular framework, consisting of the beam, and the body of the plough, so strongly connected together as to form an unyielding structure. The effect of the motive force applied to the framework at the point b, and in the line b to f, produces the same results as if c b were firmly connected by a bar in the position of the line c to b, or as if that bar alone were employed.

The average length of the trace-chains being ten feet, including all that intervenes between the clevis of the plough at b, and the horse's shoulders, let that distance be set off in the direction b to f; and the average height at the horse's shoulders, where the chains are attached, being four feet and two inches, let the point f be fixed at that height above the base-line d e. Draw the line from f to c, which is the direction of the line of draught acting upon the assumed centre of resistance c ; and if the plough is in proper trim it will coincide also with the ring of the clevis, c of being the angle of draught and equal to 20°. It will be readily perceived that, with the same length of hames, the angle e c f is invariable; and if the plough has a tendency to rise at the heel, or run on the point under this arrangement, it indicates that the ring at b is too high in the clevis. Shifting the ring one or more holes downward will bring the plough to work evenly upon the base of the land-side, or work flat.

If the plough has a tendency to rise at the point of the share, the ring b is too low, and must be moved by raising it one or more holes in the clevis. If a pair of taller horses be harnessed to the plough, the draught-chains, depth of furrow, and soil remaining the Same, we should have the point raised, suppose to f'; by drawing the line f' to c, we have e c f' as the angle of draught, which will be 22°, and the ring will be found to be below the line of draught f' c ; and if the draught chains were applied at b, in the direction f' b, the plough would have a tendency to rise at the point of the share, by the action of that law of forces which obliges the line of draught to coincide with the line which passes through or to the centre of resistance ; hence the ring would be found to rise from b to b', which would raise the point of the share out of its proper direction. To rectify this, the ring must be raised in the clevis by a space equaling that between b and b', causing it to coincide with the true line of draught, which would again bring the plough to work evenly on the base of the land-side and run flat.

The foregoing principles are substantially such as are adopted by the most experienced ploughmen, and, if properly applied, will not only do the best work, but accomplish it with the greatest ease to themselves and their team. If the power (or team) is not rightly applied, good work cannot easily be done ; for if the plough inclines in or out of the ground too much, or takes too wide or too narrow a furrow-slice, the ploughman must exert force to direct it properly, in addition to that required to overcome the obstacles and inequalities in the soil ; but if the power be rightly applied, the plough will move so accurately as not only to perform good work with more ease to both ploughman and team, but, in soils free from obstructions, even without a guide,.

To effect a proper horizontal movement, the clevis at b or draught-rod (if one is used instead of a clevis) must be adjusted and confined at that point, moving it to the right or left, if necessary. This will cause the plough to take the proper width of furrow-slice, which, in sod, should be wider or narrower according to the depth of furrow, or, rather, the thickness of the furrow-slice required for as the thickness is increased, so also must be the width in proportion, in order to turn it easily and perfectly over, particularly when the furrow-slice, are required to be laid over level and side by side. The proportion in ordinary sod should be seven by ten, or the width or depth should be varied only in this proportion.

In determining the width of furrow-slice, some regard must be had to the strength of the particular sod to be turned ; for the plough will turn over a wider slice in a strong, stiff sod than when running in one more easily broken, or it will cripple and double when raised to a perpendicular position, thus only doing the work called " cut and cover."

When the slices are required to be laid at an angle and lapped each one upon the preceding the proportion of width should be as seven to ten, thus setting the furrows at an angle of 45° which is the position of furrow presenting the greatest attainable surface to the action of the atmosphere , and the greatest cubical contents of soil to the action of the harrow in preparing a seed-bed

In Fig. 14 is shown a prairie-breaking plough. The furrows in this class of ploughing are usually about 4 inches deep, and from the fibrous roots in and compact nature of the soil the duty is very heavy; hence the length of the plough is increased, and a wheel-coulter is employed. The line of draught is regulated by the clevis being moved laterally to the width of the furrow, and vertically to steady the plough as regards depth.

The double Michigan or "sod and subsoil " plough, Fig. 18, has some important advantages. The forward or skim plough pares off a sod a few inches in thickness, and inverts it into the bottom of the previous furrow. The second or main plough follows, and throws up the lower soils completely burying the inverted sod, and giving a loose, mellow surface to the field. This forms an excellent preparation for all crops, particularly carrots and other roots, which grow best in a deep, loose bed of earth; and, where a portion of the subsoil improves the top-soil by-being mixed with it a permanent advantage results. A greater depth may be attained by the use of this double plough than with one having a single mould-board, in sod-ground, because the inversion will be complete even if the width of the furrow is only one-half the depth. But, with a single plough, the width must be considerably greater than the depth, or the sod will be thrown on its side or edge, and cannot be inverted. There is one disadvantage, however, in the use of the double plough. A greater force is required to make two cuts in the soil, one above the other, than one cut with a single share. For this reason more force must be used to plough a field to a given depth, say one foot, with the double than with the single plough. But the single plough, in order to reach this depth, would require to be so large, and to turn so wide a furrow, that no ordinary amount of team could be had to do to the work. And, in addition to this difficulty, the inverted surface would not be so well pulverized as by the use of the double plough.

Side-hill or swivel ploughs are designed to throw the furrow-slice down-hill, whichever way the plough may be moving. The plough is pivoted so that it may be moved from side to side of the beam when at the end of the furrow. The ploughing may then be done across and across the field instead of around it or in sections.

Fig. 16 is an Ames side-hill plough.








Another variety of the swivel or " turn-wrist " plough is shown in Fig. 17. It is so constructed that two ploughs attached to one beam are readily changed from one side to the other, turning the furrow-slices either to the right or left as desired. The forward plough turns, the sod to the depth of about three inches, depositing it at the bottom of the channel ; and the rear plough works to the depth of five to seven inches, raising and pulverizing the under or subsoil, and depositing it upon the forward furrow- slice, burying the sod below the reach of the harrow or cultivator.

Fig. 15 is a plough designed for deep tilling, and it may be taken as a representative of the class of ploughs used in sugar-cultivation. The line of draught is adjustable by the clevis, as shown. In the New York plough Fig. 19, the line of draught for regulating the width of the furrow is adjusted at the end of the beam where it connects with the handle-frame. The handles may be kept nearly equidistant lateral from the share given a central draught.

Fig. 20 a Scotch subsoil plough, which is used for following directly after the turning plough, and in the same furrow, breaking up, lifting a few inches, and pulverizing the subsoil.






For making roads, the class of plough shown in Fig. 21 is used. Strength and durability are here prime requisites, as the principal duty is simply to loosen the ground, cutting a width of from seven to nine inches at a traverse.

As regards the tractile power required to draw a plough, from experiments in England it appears that about 35 per cent. of the whole required draught is expended in overcoming the friction of the implement on its bottom and sides, about 55 for cutting the furrowslice and only about 10 per cent. for turning the sod. Hence the exclusive attention formerly given to forming the mould-board, as a means of reducing the draught, should have been directed more to lessening the force required for cutting the hard soil, These data are not wholly satisfactory for the light ploughs of the United States. To ascertain the amount of friction, suppose the plough weighs 100 lbs. Half its weight would be 50 lbs, the friction on the sole of the plough. The friction of the sides would vary greatly with ploughs, being very small with those having a perfect centre-draught, or with no tendency to press against the land on the left. The whole friction and force for lifting the sod would therefore be about 150 lbs.; leaving 250 lbs. as the force for cutting the slice. A very easy-running plough would leave a much smaller force-some as low as 200 lbs.

This estimate is liable to great variation. A wet and clayey soil would double the friction ; a very hard piece of ground would add much to the force required for cutting the slice; if loose, the force would be comparatively small ; or if quite moist, this force would be also much diminished; while the great difference in the draught of ploughs would vary the results still further. The estimate, however, for soil dry enough to be friable, and of medium tenacity, is probably not far from correct, for ploughing in this country-showing that most of the force required is for the act of cutting, and indicating the importance of giving special attention to the cutting edge.