A horse takes-off or commences his jump in a variety of ways, according to whether he is standing (the standing leap), ambling, cantering, or galloping. Few horses can jump properly from the trot, although it is of great advantage to be able to do so.
In the canter or gallop the animal prepares to take-off by straightening his fore-leg on the fetlock and raising his forehand; the corresponding hind-leg (usually, but not always) is next brought down, and then the other (whichever it may be), when, as stated above, he clears the obstacle by straightening the hind-limbs and projecting himself upwards and forwards. There appears to be no suspension between the straightened leading fore-leg supporting the animal and the bringing down of the first hind-foot.
In the standing leap the animal can only accomplish his purpose by rearing, and he takes advantage of the ground to the utmost by breasting the object or pushing right up to it before rising at it. Horses that can leap from the standing position are often the most troublesome to keep in bounds, while really good flying leapers can be kept at home by a low fence round a cramped paddock.
"Clever" jumpers, so-called, are those best able to judge of the time and distance in which they will have to take-off, and who prepare themselves so as to have the leading leg ready to plant at a spot near enough to and yet not too near the obstacle to be negotiated, since it will increase the length of the jump if the horse takes-off too soon, while the height may not be surmountable if too close, and the animal has to raise himself too near to a perpendicular line.
Horses with a long stride are more liable to the mistake of taking-off too "big" or jumping too soon than are short quick steppers, or those which, measuring the distance with unerring eye, put in one short step to correct the number of strides, which would else be too many or too few to bring the jump to the right spot.
The flying jumper is easier to sit, and though he seems rash he seldom comes to grief; but he cannot get one out of a narrow lane like a horse that "creeps" up to his jump and projects himself over without any residual impetus when he lands. It may be taken as a broad rule that all horses jump better from the canter or gallop, and that those able to jump nicely from the trot are scarce and esteemed, because able to perform under cramped conditions, where the flying leaper would be " pounded". The horse that can jump from the trot has the additional advantage of being able to choose from two different periods when he will take-off, these being when either of the respective diagonals comes to the ground.
The length of a horse being somewhere about 8 feet (the cavalry drill makes an allowance of 8½ feet), there is considerable length to be carried, as well as height to be surmounted, in getting over an obstacle by jumping. With these points in view, the reader will see that it is necessary for a horse to get a good spring or impetus by getting up a bit of speed some little distance from the object to be negotiated. The greater the speed at which he takes a long jump, the farther is his body projected, there being two agencies at work in propelling him, namely, the power of the muscles, to which is added the impetus gathered by the speed in approaching the jump. It is not found in practice that great speed or impetus in a forward direction (chiefly) is helpful in surmounting high jumps, and the reason is that greater weight is thrown on the forehand, and this will impose more difficulty on the leading fore-leg, whose office it is to raise the forehand off the ground. A certain angle of elevation, of course, is necessary to carry a long body over a level jump, but the angle being low, nearly all the impetus of a fast horse is expended in the right direction. Practical steeplechase-riders are wont to say that a slower pace brings out the longest jump - a pace something short of the topmost, but still having plenty of " weigh" at the point of taking-off. In jumping fences at slow paces (and these are recommended by the cognoscenti), the clever jumper before referred to gets his hind-feet as much under him as possible, so as to expend nearly all the energy gained by straightening the hind-legs in projecting his body upward. He increases the angle of elevation by raising his head. His front legs will be doubled up and his hind straightened to their utmost at the moment of taking a high jump. As to the attitude the rider should assume, there is some difference both of opinion and practice among experts, and we need not here enter into the subject beyond referring the reader to the poses of riders in the illustrations. These have been evolved out of the necessity of keeping in the saddle, and though we can conceive of certain attitudes on the part of the rider which might ease his "mount", those of our horseman on Plates LX and LXI do for the most part conform to the general laws of mechanics.
PLATE LX. THE LEAP: APPROACHING AND TAKING OFF.
[From Animals in Motion, published by Chapman & Hall. Copyright 1887 by Eadweard Muybridge.].