This frame has a transverse beam bolted underneath, and near the for ward ends of the parallel and diagonal beam. This transverse or cross beam is attached to the engine, about IS inches below the main driving axle, by two links; by this is overcome most of the tendency of the engine to lift the forward end of the plough-frame when the front wheels of the engine drop into a low place on the ground, and, again, being thus attached below the main axle, the draught of the ploughs counteracts to a great extent the disposition of the front wheels of the engine to rise off the ground when exerting great motive power, thus rendering these wheels more effectual as steering- or guide-wheels, and also overcoming the tend ency to throw the entire weight of the engine on the drivers, which always causes trouble in soft grounds or in ascending grades. The forward ends of the plough-frame are suspended by links from extensions of the main axle on both sides of the engine; this, with the steering-wheel under the rear end of the plough-frame, carries the entire frame a uniform height from the ground. This steering-wheel under the rear end of the plough frame is so connected with the front axle of the engine that both wheel and axle change their direction of travel at the same time, though in oppo site directions; that is, when the front axle of the engine is turned to the right, the guide-wheel of the plough-frame is turned to the left, so as to cause the entire machine to move in a curved line, the arc of which always has the same proportion to the angles as the front axle of the engine and the guide-wheel of the plough-frame have to the driving- or main axle of the engine. This renders it practically impossible for the engine and the ploughs to move in any other course than the one desired. The ploughs arc lifted out of the ground by means of a steam-cylinder operated by the engineer. It is claimed that this plough will in ten hours plough a field of fifteen acres, making a cut of 7 feet and ploughing at the depth of SYz inches in hard dry ground, and that the expense for the work is not one third as much as if performed by horses.
Imp/meals for a field has been ploughed, some implement is generally employed to bring the soil to a condition fit for the reception of the seed. The common square-tooth harrow with teeth set at right angles to the frame was for a long time the only implement used for this purpose. It was an imperfect pulverizer, as the teeth were drawn square against the soil and were easily clogged. This has been
generally superseded by several inventions whose object is to secure lighter draught, freedom from clogging, and a more perfect pulverization of the soil. Among these may be mentioned the Acme harrow (p/. 57, fig. 4) and the disc-harrow (fig. 5).
The Acme Harrow (fig. 4) is particularly adapted for working a ploughed-under sod. It has two rows of broad-cutting steel blades slop ing backward and having a partial twist, like the mould-board of a plough. These "curved coulters" cut the land into slices and break up the surface, while the sod, which is undisturbed, is firmly pressed under and left in the very best condition and position.
The (fig. 5) consists of twelve circular thin steel plates made slightly concave, to assist in pulverizing the soil. These discs, which are set slightly oblique to the line of draught in two gangs of six each, turn on a common axle and with a rolling motion cut through the soil, which by their turning is cast slightly sidewise and formed into small ridges about 6 inches wide. To this harrow there can be attached a seeder, thus two complete implements in one.
Rollers of a variety of pattern are also constructed for crushing clods and compacting the soil. As an example we give Provost's flexible field roller (fig. 2), which is so constructed that the two large sections (drums) rise and fall in the middle, to conform to the unevenness of the earth, while in front of the middle there is attached a smaller drum, which presses down the seam of land left unrolled by the larger sections.
Figure I illustrates a roller for meadows or grain-fields or corn-land after planting. The two sections, each 3 feet in length, are supported on an arbor 6 feet S inches between the bearings, thus allowing for a space of S inches between the drums and enabling the operator to stride a row of growing corn, while each drum covers time space between two rows. The space between the drums is filled by two 4-inch spools, which can be taken off the arbor and placed one at each of its ends, thus closing the space in the centre and making a solid 6-foot roller for muse on meadows or grain land.
Figure 3 shows a combined clod-crusher, pulverizer, and corn-stalk cutter, which will cut two rows of corn-stalks at one time, while it will effectually pulverize large clods, leaving the ground so perforated that it will not readily bake in case of rain. When used merely as a clod-crusher, the position of the tongue is reversed.