More Science from an Easy Chair

by Sir E. Ray Lankester

On these grounds I find that the most satisfactory pictures of the galloping horse are those which combine a phase of the movement of the front legs with a phase of the movement of the hind legs, not simultaneous in actual occurrence, but following one another. It is for the artist to select the combination best suited to producing the mental result aimed at. Some of the Chinese and Japanese representations of the galloping horse and some of their European imitations (but not all—certainly not that of Stubbs, of the Epsom Derby of Géricault, and the racing plates) seem to me to be eminently satisfactory and successful in this respect. In the pictures to which I allude (Pl. III, figs. 3 and 5) all the legs are off the ground; the front legs are advanced, but one or both may be more or less flexed, whilst the hind legs, though directed backwards with upturned hoofs, are not nearly horizontal (as they actually are in the galloping dog), but show the moderate extension which really occurs in the horse, and is recorded by instantaneous photography. This pose, favoured by many European and Japanese artists, can be obtained by uniting the outstretched hind legs of fig. 9 of the Muybridge series (Pl. I), with the outstretched forelegs of fig. 6, as shown in Pl. I, fig. 12, or by uniting the hind legs of fig. 10 with the forelegs of fig. 4 as shown in Pl. III, fig. 1.

With regard to the representation of other "gaits" of the horse than that of the rapid gallop—such as canter, trot, amble, rack, and walk—I have no doubt that instantaneous photography can (and in practice does) furnish the painter with perfectly correct and at the same time useful and satisfactory poses of the horse's limbs. These, though of longer duration than the poses of the gallop, can only be correctly estimated by the eye with great difficulty, and only sketched by artists of exceptional skill and patience. The movement of the wings of birds in flight has been very successfully analysed by instantaneous photography. Some of the poses revealed must familiarise the public with what can be, and, in fact, has been, observed in the case of large sea-birds, by the unassisted eye, and has been represented in pictures by the more careful observers of nature among modern painters. A large sea-bird sailing along with apparently motionless wings has been photographed in the act of giving a single stroke so rapid as to escape observation by the eye.

An interesting question in regard to the movements of the horse is that as to how far any known "pace" is natural to that animal, and how far it has been acquired by training and is, in a sense, artificial. We know so little of the wild horse, and of the more abundant wild asses and zebras, that it is difficult to say anything precise on this question. There is only one region in which the true original wild horse of the northern part of Asia and Europe still exists. That is the Gobi Desert, in Central Asia. This horse is known as Prevalsky's wild horse, in honour of the Russian traveller who discovered it. Live specimens are now to be seen in the Zoological Gardens and elsewhere. It closely resembles the drawings of horses made by the palæolithic Cromagnard cave-men. A century ago a wild horse, probably of the same race as this, inhabited the Kirghiz Steppes, and was known as the Tarpan: it is now extinct. The more southern Arabian horse is not known in the wild state, whilst the wild horses of America are descendants of domesticated European horses which have "run wild." I do not know of any studies of the movements of the true wild horse, nor of those of wild asses and zebras, carried out by the aid of instantaneous photography. It would be interesting to know whether untaught wild "equines" would fall naturally into the gaits known as "the amble" and "the rack," or whether the walk, the trot, and the gallop are their only natural gaits.

The amble, in which the fore and hind leg on the same side are advanced simultaneously, is a natural gait of the elephant, the fastest Muybridge could get from that great beast. He made a menagerie elephant amble at the rate of a mile in seven minutes. The only other animal known to habitually exhibit "the amble" is the giraffe. It is often exhibited by the giraffes in the Zoological Gardens in London, but has not, I believe, been recorded by a series of instantaneous photographs. When going at full speed over the grass wilds of Central Africa the giraffe exhibits a gait more like the galloping of deer and antelopes, and carries the long neck horizontally. No complete study of the "gaits" of large animals other than the horse has been made, since menagerie specimens and menagerie conditions are not satisfactory for the purpose, and, unfortunately, it has not been possible as yet to take series of photographs of them in their wild conditions.

The electric spark furnishes a most important means of taking instantaneous photographs, but the operator must perform in the dark. An electric spark can be obtained which lasts only the one two-thousandth of a second, and by its use as the sole illuminating agent we can get a photograph of a phase of movement lasting only that excessively short space of time, or, if we please, a succession of such phases by using a succession of sparks. Thus, a rifle bullet is readily photographed while in flight with scarcely perceptible distortion. A wheel revolving many hundred times a second can thus be photographed, and appears to be stationary. Dr. Schillings has applied this method to the photography of wild animals by night in the forests of tropical Africa, and has published an interesting book giving his photographic results. In order to take these pictures the track followed by certain animals has to be detected, and then a thread is stretched "breast-high" across the track, so that the animal coming along it by night shall pull the thread. Immediately the thread is pulled it sets an electric contact in action. There is a brief flash of one two-thousandth of a second, and a picture is taken by a camera previously fixed, out of harm's way, so as to focus the area where the thread was stretched.

Dr. Schillings obtained some very remarkable photographs of "the night life of the forest" in this way—lions and leopards advancing on their prey were suddenly revealed, and the helpless antelope or other victim was shown crouching in the dark, or making a desperate effort to escape.

The electric-spark method was applied by a friend of mine to demonstrate the movements by which a kitten falling backwards from a table succeeds in turning itself so as to alight on its feet. During a fall of less than 3 feet he obtained five successive spark-pictures of the kitten, which, I beg it may be clearly understood, was a pet kitten, and was neither frightened nor hurt by the proceedings.

Instantaneous photographs, whether obtained by the use of an electric spark as a means of illumination, or by the less rapid method of a spring shutter working in combination with a sensitive film, which is jerked along so as to be exposed when the shutter is open and travel when it is shut, has been applied to the analysis of other movements than those I have mentioned, and has yet to be applied to many more, such as the crawling of insects and millipedes, and the beautiful rippling movement of the legs and body by which many marine worms swim. It has been extensively used in the study of human locomotion, and of the successive poses of the arms and legs in various athletic exercises, and in such games as baseball and golf.

A first-rate fencer of my acquaintance had a five-minutes' film of himself taken when fencing, giving 10,000 consecutive poses. He wished to see exactly what movements he made, and to ascertain by this minute examination any error or want of grace in his action, in order to avoid it. An unexpected picture is obtained when a man or woman is thus "biographed" whilst walking rapidly, and suddenly turns to the right or left. A fraction of a second occurs when the toes of the two feet are directed towards one another (that is to say, are "turned in"), as one of the legs swings round in the break-off to right or left. This instantaneous phase is very awkward and ugly in appearance. It is never pictured by artists, although regularly occurring, and seems to have been as little known before instantaneous photography was introduced as were most of the phases of the horse's gallop. The positions assumed when in the air by a high-jump athlete are almost incredible as revealed by the camera. He appears to be sitting in a most uncomfortable way on the rope over which he is projecting himself.

A very fine attitude is fixed for the artist in one of Muybridge's instantaneous series of the "bowler"—the cricket "bowler." The up-lifted right arm, the curve outwards of the whole figure on the right side, and the free hang of the right leg make a most effective pose for a sculptor to reproduce. Among the most remarkable results obtained in Muybridge's series are the stages of the growth or development of strong "expression" in the face. The anxiety in the face of the baseball batsman as he awaits the ball is painful; as he hits at the ball his expression is one of savage ferocity, and in a fraction of a second this gives place to a dawning smile, which as we pass along two or three later "instantanèes" develops into a broad grin of satisfaction. Another genuine study of expression both of face and gesture and movement is given in the series where a pailful of cold water is unexpectedly poured over the back of a bather seated in a sitz bath—astonishment, dismay, anger, eagerness to escape, and the reaction to shock are all clearly shown. Darwin's studies on "the expression of the emotions" would have been greatly assisted by such analysis, and the subject might even now be developed by the use of serial instantaneous records obtained by photography. It may be useful to those interested in this subject to know that copies of Muybridge's large series of instantaneous photographs[3] of animal and human subjects in movement are preserved both in the library of the Royal Academy of Arts in London and in the Radcliffe Library at Oxford. I may also mention the extremely valuable series of instantaneous photographs of living bacteria, blood-parasites and infusoria produced by MM. Pathé, and the series of fishes and various invertebrates (including the curious caterpillar-like Peripatus) taken by Mr. Martin Duncan.