This section is from "The Horticulturist, And Journal Of Rural Art And Rural Taste", by P. Barry, A. J. Downing, J. Jay Smith, Peter B. Mead, F. W. Woodward, Henry T. Williams. Also available from Amazon: Horticulturist and Journal of Rural Art and Rural Taste.
In leaping, the horse raises the fore legs from the ground, and projects the body upwards and forwards by the hind legs alone. It Is well known that they leap rivulets, hedges, and ditches, with great ease, even under the burden of heavy riders; but, to accomplish this, an enormous expenditure of muscular action mast be required, since the muscles which produce the effect act at a great mechanical disadvantage.
Horses which are constituted for great speed, have the shoulder-joints directed at a considerable angle with the arm. Saintbell has given the relative proportions of the several parts of the skeleton of the celebrated race-horse, "Eclipse," together with the angles of inclination and range of motion belonging to the joints and legs. According to his account, that horse, when galloping at liberty, and at its greatest speed, passed over twenty-five feet at each step; these strides were taken two and a half times in a second, being at the rate of about four miles in six minutes and two seconds, or forty miles in an hour and twenty seconds.
The subject has puzzled very wise heads, and will interest all those who love a fine horse.