Part 6

Selecting for the purpose of illustration the phases occurring during two steps or one-half of a stride of 18 feet in length by a horse trotting at the rate of a mile in two minutes and twelve seconds, we find that at the instant his right fore foot strikes the ground, the left hind foot is a few inches behind the point where it will presently strike. As the feet approach the ground, the right hind leg is drawn forward with the pastern nearly horizontal, while the left fore leg is flexed under the body. After the feet strike the ground and the legs approach a vertical position the pasterns are gradually lowered, and act as springs to break the force of the concussion until they are sometimes bent to a right angle with the legs.

At this period the fore foot is raised so high as to frequently strike the elbow, while the diagonal hind foot is comparatively but little above the ground, and is about to pass to the front of the left hind.

The pasterns gradually rise as the legs pass the vertical until the right fore foot has left the ground and the last propelling force is being exercised by the left hind foot; which accomplished, the animal is in mid air.

The right hind foot continues its onward motion until it is sometimes much in advance of its lateral fore foot, the former, however, being gradually lowered, while the latter is being raised. The right hind and both fore legs are now much flexed, while the left hind is stretched backwards to its greatest extent with the bottom of the foot turned upwards, the left fore leg is being thrust forwards and gradually straightened, with the toe raised as the foot approaches the ground; which accomplished, with a substitution of the left limbs for the right, we find them in the same relative positions as when we commenced our examination, and one-half of the stride is completed.

With slight and immaterial differences, such as might be caused by irregularities of the ground, these movements are repeated by the other pair of diagonals, and the stride is then complete.

If the stride of a trotting horse is divided into two portions, representing the comparative distances traversed by the aggregate of the body while the feet are in contact with, and while they are entirely clear of, the ground, the relative measurements will be found to vary very greatly, they being contingent upon length of limb, weight, speed, and other circumstances.

Heavily built horses will sometimes merely drag the feet just above the surface, but, in every instance of a trot, the weight of the body is really unsupported twice during each stride. It sometimes happens that a fast trotter, during the four steps of a stride, will have all his feet clear of the ground for a distance exceeding one-half of the length of the entire stride. Upon landing, a fore foot almost always precedes its diagonal hind.

It will be observed in the illustrations that while during the fast trot the fore feet are lifted so high that they frequently strike the breast, the hind feet are raised but little above the surface of the ground. The trot is common to all the single-toed and to nearly all the cloven-footed and soft-footed animals. It has, however, not been recorded as being adopted by the elephant, the camel, or the giraffe.

THE RACK.

The rack, sometimes miscalled the "pace," is a method of quadrupedal locomotion in which two lateral feet with nearly synchronous action are placed upon and lifted from the ground alternately with the other laterals, the body of the animal being in the intervals entirely without support. The distance which the propelling feet hurl the animal through the air depends, as with other movements, upon a variety of circumstances; at a high rate of speed the distance will be about one-half the total length of the stride. Upon landing, a hind foot usually precedes its lateral fore.

The rack is an ungraceful gait of the horse, and disagreeable to those who seek comfort in riding.

The movements hitherto described are regular in their action, and a stride may be divided into two parts, each of which--with a change of limbs--is practically similar to the other; we now come to methods of progression which cannot be so divided, and each stride must be considered as a unit of motion.

THE CANTER.

In the canter we discover the same sequence of foot fallings as in the walk, but not with the same harmonious intervals of time. The gait resembles the gallop in respect to its leaving the horse entirely unsupported for a varying period of time, and in the fact that the spring into the air is always effected from a fore foot, and the landing upon the diagonal hind foot; in other respects it materially differs from that method of progression.

Assuming that during a stride of the canter a horse springs into the air from a left fore foot, the right hind foot will first reach the ground; the two fore legs will at this time be flexed under the body, the right being the first landed, and for a brief period of time the support will devolve upon the laterals. The right fore foot is rapidly followed by the left hind. During a very slow canter the other fore foot will sometimes be landed in advance of the lifting of its diagonal, and the curious phase presented of all of the feet being in contact with the ground at the same instant. Usually, however, the first hind foot to touch the ground will be lifted, and the support thrown upon the diagonals.

The left fore is now brought down, and is followed by the lifting of the right fore; when the left laterals assume the duty of support. The left hind is now raised, and with a final thrust of the left fore foot the animal is projected into the air, to land again upon its diagonal, and repeat the same sequence of movements.

The above phases are selected from a single complete stride, in which the landing occurs on the right hind foot. Had the horse sprung from a right fore foot, the right and left feet would have been reversed through the entire series.

THE GALLOP.

The gallop is the most rapid method of quadrupedal motion; in its action the feet are independently brought to the ground; the spring into the air as in the canter is effected from a fore foot, and the landing upon the diagonal hind foot.

The phases illustrated are selected from the stride of a thorough-bred Kentucky horse, galloping at the rate of a mile in a hundred seconds, with a stride of about twenty-one lineal feet.

The length of stride and the distance which the body is carried forward without support depend upon many circumstances, such as the breed, build and condition of the horse, speed, track, etc.

The phases illustrated and the measurement given apply to one stride of one horse, but may be considered as fairly representing the stride of a first-class horse in prime racing condition at the height of his speed, upon a good track.

Assuming--as in this instance--the springing into the air to have been effected from the right fore foot, the landing will take place in advance of the centre of gravity, upon the diagonal, or left hind foot; above, will be suspended the right hind foot, and at a higher elevation, several inches to the rear, will be the right fore foot, with the sole turned upward. The left fore leg will be in advance of the right, and also flexed. The force of the impact and the weight of the horse causes the pastern to form a right angle with the leg, and the heel is impressed into the ground.

The right hind foot strikes the ground and shares the weight of the body. The left hind foot leaves the ground while the right hind pastern is in its horizontal phase, supporting all the weight. At this period the left fore leg is perfectly straight, with the toe much higher than the heel, and is thrust forward until the pastern joint is vertical with the nose, the right fore knee is bent at a right angle. The left fore foot now strikes and these diagonals are for a brief period upon the ground together. The left fore leg, however, immediately assumes the entire responsibility of support and attains a vertical position, with the pastern at a right angle. The right fore leg becomes perfectly rigid, and is thrust forward to its fullest extent. The right fore foot now strikes the ground, the two fore legs form a right angle, and the hind feet are found thrust backward, the right to its fullest extent. The left fore leg having completed its functions of support, is now lifted, and the weight transferred to the right fore foot alone, which is soon found behind the centre of gravity; the left hind foot passes to the front of the right fore leg, which, exercising its final act of propulsion, thrusts the horse through the air; the left hind foot descends; the stride is completed, and the consecutive phases are renewed. From this analysis we learn that if the spring is made from the right fore foot during the rapid gallop of a thoroughbred horse, it is supported consecutively by

The left hind foot.

Both hind feet.

The right hind foot.

The right hind and the left fore feet.