which exists on either side is soon reduced to a very small part of the circle, for as soon as segment 7 is entered upon the heel should be sharply dropped, and an upward and forward kick or thrust, as described in the directions for the first position, will lift the pedal forward and upward through segment 8, when, of course, the whole series of actions will be repeated.’—_Bicycling News._” Using the arrangement of cyclograph spoken of, by which ankle-motion may be shown, I find that I can begin to get a tangential resultant force on each crank at an angle of eighteen degrees back of the vertical line through the axle of the drive-wheel, beginning at _d_ and ending at _e_, Fig. 1,—in all, thirty-six degrees over a half-circle on each crank. [Illustration: Fig. 1. Ankle-power.] The diagram shows the sections 1 to 8, and also gives an idea of the extra power. To see the direct circular resultant force to turn the wheel, imagine the length of a crank from _m_ to _n_ without ankle-motion and then _m n_ plus _n o_ for the length of the crank with ankle-motion added. I have been able at each of the points _a_ and _i_ to get thirty pounds when the crank crosses the vertical line at the top and bottom. Thus it is discovered that by means of this ankle-motion on both cranks simultaneously, I can get a force of sixty pounds in the direction to turn the wheel, at a time when absolute dead centre would otherwise occur, amounting to two-fifths of the maximum pressure resulting from my entire weight on one crank at the best possible point, directly out in front, going down. I have more than verified the results shown by the cyclograph by suspending a fifty-four-inch bicycle, with six-inch cranks, above the floor, placing myself in the saddle, and having an attendant attach a twenty-pound weight at a point on the rim, ninety degrees from the bottom. This weight I was able to raise at the dead-centre point of both cranks,—that is, vertically up and down,—which shows a real power at the pedals of ninety pounds, or forty-five pounds on each, and I do not suppose that I am by any means an expert in ankle-motion. The above ninety pounds is a much greater showing than I made on the cyclograph in actual running, but it is reasonably certain that, by practice, even such an amount could be obtained. In the case of no ankle-motion,—that is, with a direct downward pressure on the crank,—a tangential force in the direction available in turning the wheel begins as the crank crosses the vertical at the top, and then increases as the sine of the angle the crank makes with the vertical, until such angle reaches ninety degrees or extends out horizontally, after which the power decreases as the sine of the angle the crank makes with the vertical below the centre until the crank crosses at the bottom, at which point the power ceases.