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.
Editor Horticulturist: The young people of our neighborhood have interested their elders in the subject of the manner in which a horse moves his legs and feet, which, it seems, we have disagreed on. Will you please to settle it?
Distinguished anatomists and philosophers, no less than the unlearned, have fallen into gross mistakes upon this subject, in consequence of trusting to theoretical opinion rather than to the evidence of observed facts. There is more than one statue in the world mounted upon horses with their legs in positions that would never keep them up.
A late English Cyclopedia places this subject in its true light; as it possesses interest to all our readers, with the aid of four or five woodcuts we proceed to make it intelligible.
Quadrupeds move their four legs either singly or successively, or in various orders, which correspond with the different velocities of the animal. Theee different kinds of movement of the legs are known under the terms walking, trotting, galloping, and leaping. The horse illustrates the manner in which the locomotion of quadrupeds in general is effected. Though the subject possesses more or less interest to most persons, yet of the millions of people who are in the daily habit of seeing the horse in motion, how very few consider the means by which the movements of that valuable animal are performed, and are, consequently, in the condition of our inquiring correspondent.
Let us suppose the horse to be standing on its four legs (as in Fig. 4), and that it commences the walking step by moving its left hind leg (as in Fig. 1); this having been advanced, and placed on the ground, the right fore leg is next raised and advanced (as in Fig. 2), and having been placed on the ground, the right hind leg performs a similar movement, and the legs of the animal are in the position Fig. 3. Lastly, the left fore leg is advanced, and placed in the position of Fig. 4. These four movements complete the step, and during the series, the centre of gravity of the animal passes over a corresponding space. This is the order in which nearly all quadrupeds move their legs in slow walking; but some authors do not coincide in this statement, amongst whom is Borelli, who has figured the horse as moving both the legs on the same side at once in walking, as some horses are taught to do in the amble, and as the giraffe is known to do naturally.
Locomotion of Horses.
A little consideration will clear up the error into which Borelli and others have fallen, respecting the horse. It will be observed, from the foregoing statement, that the. left hind leg moves first, the right fore leg second, the right hind leg third, and the left fore leg fourth. Now, if we do not analyze this order of motion from its commencement, we may be easily deceived; for, in walking by a horse, the two legs appear indeed to move together on the same side; but this arises from the continuity of the series of movements, which we find begins with the left hind leg, and terminates with the left fore leg, the movement of the right fore leg being in like manner followed by that of the right hind leg, which continuity of movement, if not carefully discriminated, gives an impression that the animal moves both legs on the same side simultaneously.