upon a reasonably smooth level road. Why we have been able to thus improve upon nature’s device is not quite clear. Undoubtedly, however, there is some unnecessary friction in the leg method; it cannot be on account of impact with the air, because a man on a bicycle certainly catches as much air himself, in addition to that of the machine, as he would do in walking. Evidently, then, there must be more motion or extra friction or both in the body, in the leg method, than is really essential in conveying one over a good road. Probably the main cause of this friction is that the rider’s body is supported differently; it requires less muscular strain to sit than to stand. We not only know this from experience, but it is proved by the fact that the temperature of the body is lower while sitting than while standing; also still lower when lying down, showing that less energy is being expended and less muscle consumed. Since the spirit of the writer began to wrestle with the foregoing leg versus cycle controversy, by happy chance he fell upon an estimable work[2] of which a careful perusal would almost make us think that nature really had an embryo cycle or wheel method in view when we were planned for legs. The great interest attaching to the above-mentioned work arises from the fact that the book was written before the cycle was at all broadly known to be of any assistance to the self-propulsion of man under any circumstances. This work must be read to be appreciated. I give some quotations, the application of which shows that, in the minds of some, the Creator had an idea of a wheel within a wheel; in short, that nature seemed to want to roll. Let us quote from page 51, “Animal Locomotion.” “When the right leg is flexed and elevated, it _rotates_ upon its iliac portion of the trunk in a forward direction to form the _arch_ of a _circle_ which is the converse of that formed by the right foot, if the _arcs_ alternately supplied by the right foot and the trunk are placed in opposition, a more or less _perfect circle_ is produced, and thus it is that the locomotion of animals is approximated to the wheel in mechanics.” Hence we _roll_,—but not far enough,—we approximate in nature, but reach the goal by man’s genius; shown in the full circular wheel. It will be seen from the following (p. 51) that the bones in man are not arranged for high speed; hence we must make up for this deficiency. “The speed attained by man, although considerable, is not remarkable; it depends on a variety of circumstances, such as height, age, sex, and muscular energy of the individual, the nature of the surface to be passed over, and the resistance to forward motion due to the presence of air whether still or moving. A reference to the human skeleton, particularly its inferior extremities, will explain why the speed should be moderate.”