Page:Willich, A. F. M. - The Domestic Encyclopædia (Vol. 4, 1802).djvu/234

208&#93; 2o8] THR Thefirst tbrashin^machincwhich has come to our knowledge, is that manufa(5lured, in l732,byMr. MichaelMenzies of Edinburgh : it consisted, as far as we have been able to ascertain, of numerous in- struments, resembling flails, which were attached to a moveable beam, and inclined to the latter m an an- gle of 10 degrees. On each side of such beam, were placed fkxns, or benches, on which the shea'es were spread ; the flails being moved forward and backward on these benches by a crank, that was fixed to the end of an axle, revolving about 30 times in a minute. Tlie second machine was in- ventetl, in 1753, by Mr. Michael Sterling, of Dunblaine, Perth- shire : his first models were veiy imperfeft ; but, after repeated alte- rations, he completed it in its pre- sent form, in 1758 ; and it now consists of an outer, or water- wheel, having an inner wheel, furnished with 48 cogs, and turn- ing on the same axle. With this cog-wheel is connefteAl a vertical trundle, or pinion, with 7 notches; and the axle of which passes through a floor above the wheel ; its upper pivot being secured in a beam 6 inches above the floor. At the height of 3 feet 3 inches from the latter, 2 straight pieces of sijuared wood (each being 4 feet in length) arc inserted through the axle of the pinion, at right angles, so as to form 4 arms, that are moved round horizontally. To the ends of these arms are affixed 4 iron plates, each 20 inches in length, and 8 inches in breadth at the extremity nearest to the arm", but tapering to a point at the op- posite end. The horizontal fly, here de- scribed, constitutes four thrashtrs, THR and is inclosed in a cylindrical •wooden box, that is 3^ feet high, and 8 feet in diameter : on the top of this box is an opening 8 inches in width, extending a foot and a half from the circumference to its centre, and through which the sheaves of corn descend ; the lat- ter being previously opened, and laid separately on a board provided with two ledges, graduallydeclining towards such port, or opening. — ' Within the cylindrical box, there is an inclined plane, along which the straw and grain fall into a wire riddle two feet square, that is placed immediately beivath a hole of a similar size : — the rid- dle is jerked at each revolution of the spindle, by means of a knob fixed on its side ; and is thrust backward by a small spring that presses it in a contrary dire6tion. Thus, the short straw, together with the grain and chaff, that pass through the wide riddle, fall in- stantly into an oblong, straight rid- dle, one end of which is raised, and the other depressed, by a similar contrivance. And, as the riddle last- mentioned is not provided with a ledge at the lower end, the long chaffs, which cannot pass through, drops thence to the ground, while the grain and smaller chatF descend into a pair of common Lam-fan. 7it'rs, and are thus separated with great exaftness. These fanners are nioved by means of a rope, that nms in a shallow groove cut on the circumference of die cog-wheel. In t!,e mean time, the straw col- leded in the lower part of the box over the wide riddle, and through an opening 2^ feet square, is drawn down to the ground with a rake, by the persons employed to form it into trusses. In 1772, another tbrashing- xnachi&e