tnachlne was invented by Mr. Alderton, of Alnwick, and Mr. Smart, of Wark, Northumberland. The operation was performed by rubbing ; the sheaves being car- ried round between an indented drum 6 feet in diameter, and nu- merous indented rollers, that were arranged round, and attached to, this drum by means of springs ; so that, during the revolution of the machinery, the corn was separated from the straw, by constant fridion against the flufings of the drum. But this contrivance was soon dis- used J as many grains were thus crushed between the rollers. The next invention, is that of Mr. Andrew Meikle, in 1/85, who obtained a patent, which is now expired : we have therefore given a plate, representing in Fig. 1, the plan of elevation j in Fig: 1, tlie ground planj and in Fig. 3, the essential parts of the machinery, so as to convey a tolerably accurate idea of his principle. Description of Mr. Andrew Mei- kle'5 Improved Thrashing Ma- chiiie. A, (Fig. 1, and 2), is a large horizontal spur-wheel, which has 2/6 cogs, and moves the pinion B, Iiaving 14 teeth. The latter im- parts motion to a crown-wheel, C, that is provided with 84 cogs, and moves a second pinion, D, which is furnished with teeth. This pinion, D, turns the driim H, I, K, L, (Fig. I, 2, and 3), being a hollow cylinder, 3| feet in diameter, and jplaced horizontally : on its ontslde are fixed, by rneans of screw-bolts, four scutchers, or pieces of wood, Cne side of which is faced with a thin iron plate j and which are disposed at an equal distance from each other, and at right angles to tJife axis of the drum.
- o. XJV, — vol., IV,
f fir i [209 V, ('Pig. 2, and 3), is an inclined board, on which the sheaves are spread, and whence they are in- troduced between two fluted cast- iron rollers, G, G, fFig. 3), that are 3|- inches in diameter, and re- volve about 35 times in one minutel These rollers, being only three- fourths of an inch from the scutchers or leaves of the drum H, I, K, L, (Fig. 1, and 2), serve to keep the sheaves steady, while the scutchers a, I, c, d, (Fig. 2, and 3), move with uncommon velocity, and thus separate the grain from the straw, while both are thrown on the con- cave rack M, (Fig. 1), which lies horizlontaliy with slender parallel ribs J so that the corn may pass through them, into the subjacent hopper N, (Fig. 1, and 3). O, (Fig. 3), is a riddle or harp, through which the corn drops into a pair of fanners, ?, (Fig. 1, and 3), and from these it is generally obtained in a state fit for the market. Q, R, T, S, is a rake, consisting of four leaves, or thin pieces of wood : at the extremity of each is placed a row of teeth e, f, g, k, that are five inches long. This rake moves in the concave rack M, (Fig. 2), in a circular direc- tion ; while the teeth catch the straw, that had been thrown by the scutchers c, b, c, d, into th© rack, and remove it to the contigu- ous place, V. W, (Fig. 1), represents the horse's course, which is 27 feet in diameter. X, (Fig. , and 2), id the pillar for supporting the beams, on which the axle of the spur-wheel is fixed. Y,y, Y, (Rg.l), and Y,Y, (Fig. 2), shew the spindles, the design of which is to move the two fluted rollers, the rake, and the fenne^r*. f. ^> (Fig.
