This invention consists in the addition of a fine uppermost riddle, G, long enough to extend back under the hopper of the winnower and back over the double sloping screen, H, and resting on the whiffle tree. The advantages which this winnower possesses are briefly as follows. A finer riddle is used to begin with, there is a more thorough cleaning, and by its size the bouncing and scattering of the grain is prevented, and all the dust, filth, white caps and other matter are kept out of the machine. The grain is quickly and thoroughly cleaned and less large grains get mixed with the tailings than is usually the case. Our engravings fully illustrate the invention, Fig. 1 being a perspective view, and Fig. 2 being a vertical section through the machine. Similar letters indicate the same parts in each. A is the hopper into which the grain to be cleaned is placed and it falls through the small aperture a, on the top riddle or screen, G, from that to the next screen, g, and then to the double sloping screen, H, which thoroughly and evenly distributes the grain over the remaining screens, I, J, K. These screens are secured at the projjer distance apart by a screw rod, I, and are of wire webbing of different degrees of fineness ; they are mounted in a shoe or shaker, L, which is operated from the axle of the fan in the usual manner. At the side of the box are openings provided with sliding doors, F, through which the cockle can escape when desired. The blast is created in the usual way by means of a fan, C, rotated very rapidly by the gearing, D, and crank handle E. The large grain being less influenced by the draft, falls through the spout, Q, the second quality falls through the spout, 0, into the spout, P, by which it is conducted away ; the tailings pass through the open space, M, being kept from being blown away by the inclined board, N. It was originally patented April 20, 1852, and another patent was secured for additional improvements, Dec. 15 1857, by the inventor, Thos. J. Doyle, of Stanton, Va., from whom all further information can be obtained.