“The seeder covers the soil to a uniform depth. It sows evenly, and sows a specific quantity. You may graduate it so that, after a little experience, you can determine the amount per acre even to a quart of wheat. They sow all kinds of grain,--wheat, clover, and superphosphate, if need be, at once. They harrow at the same time. They make the crop more certain. It is the united testimony of manufacturers and farmers alike that the crop is increased from one-eighth to one-fourth, especially in the winter wheat. Winter wheat, you are aware, in the freezing and thawing season, is apt to heave out. It is desirable to bury the seed a uniform and proper depth and to throw over the young plant such an amount of soil that it shall not heave with the freezing and thawing. Of the 360,000,000 bushels of wheat raised last year I suppose more than 300,000,000 was winter wheat. One-eighth of this is 37,700,000 bushels.” It would seem to many that after the adoption of a seed hopper, and spouts with sharpened ends that cut the drill rows in the furrows and deposited the seed therein, that little was left to be done in this class of inventions; but a great many improvements were necessary. Gravity alone could not be depended upon for feeding the seed. Means had to be devised for a continuous and regular discharge from each grain tube; for varying the quantity of the seed fed by varying the escape openings, or by positive mechanical movements variable in speed; for fixing accurately the quantity of seed discharged; for changing the apparatus to feed coarse or fine seed; and for rendering the apparatus efficient on different surfaces--steep hillsides, level plains, irregular lands. An important step was the substitution of what is called the “force feed” for the gravity feed. There is a variety of devices for this purpose, the principle of one of them being a revolving feed wheel located beneath the hopper, and above each spout, the two casings between which the feed wheel revolves forming the outer walls of a complete measuring channel, or throat, through which the grain is carried by the rotary motion of the wheel, thus providing the means of measuring the seed with as much accuracy as could be done by a small measure. The quantity sown per acre is governed by simply increasing or diminishing the speed of the feed wheel. In one form of device this change of speed is altered by a system of cone gearing. A graduated flow of the seed has also been effected by the employment of a cylinder having a smooth and fluted part working in a cup beneath the hopper with provision for adjustment of the smooth part towards and from the fluted part to cut off or increase the flow.