delight of our nurseries, have been produced without disregard of Mr. Ruskin's preposterous doctrine.

In the same lecture Mr. Ruskin opposes with the utmost vehemence the theory of evolution and natural selection, and the æsthetic rule founded on it, according to which vertebrate animals should not be represented with more than four legs. Can any law be conceived," he says, more arbitrary, or more apparently causeless? What strongly planted three-legged animals there might have been! what systematically radiant five-legged ones! what volatile six-winged ones! what circumspect seven-headed ones! Had Darwinism been true, we should long ago have split our heads in two with foolish thinking, or thrust out, from above our covetous hearts, a hundred desirous arms and clutching hands, and changed ourselves into Briarean Cephalopoda."

Obviously, this false prophet has no notion of what in morphology is called a type. Can it be necessary to remind a countryman of Sir Richard Owen and Prof. Huxley that the body of every vertebrate animal is based on a vertebral column, from which it derives its name, expanding at one end into a skull, reduced to a tail at the other, and surrounded before and behind by two bony girdles, the pectoral and the pelvic arches, from which depend the fore and hind limbs with their typical joints? The very fact that palæontology has never known any form of vertebrate animal to depart from this type is in itself a striking argument in favour of the doctrine of evolution, and against the assumption of separate acts of creation; there being no reason why a free creative Power should have thus restricted itself. So little will Nature deviate from the type once given, that even deformities are traced back to it by teratology. They are not really monstrosities; not even those with a single eye in the middle of the forehead, which Prof. Exner takes to be prototypes of the Cyclops, Flaxman being certainly mistaken in representing Polyphemus with three eyes-two normal ones which are blind, and a third in the forehead. Real monstrosities are those winged shapes of Eastern origin, invented by a riotous fancy while art was in its childhood: the bulls of Nimrûd, the Harpies, Pegasus, the Sphinx, the griffin, Artemis, Psyche, Notos of the Tower of Winds, the goddesses of Victory, and the angels of Semitic-Christian origin. A third pair of extremities, (Ezekiel even admits a fourth) is not only contrary to the type, but also irrational in a mechanical sense, there being no muscles to govern them. In the "Fight with the Dragon," Schiller has happily avoided giving his monster the usual pair of wings; and in Retzsch's illustrations its shape agrees so far with comparative anatomy as to recall a Plesiosaurus or Zeuglodon returned to life and changed into a land animal ; indeed, the resemblance between those animals and the mythical dragon has led to the question whether the first human beings might not have actually gazed upon the last specimens of those extinct animal races. An abomination closely related to the winged beasts are the Centaurs, with two thoracic and abdominal cavities, and a double set of viscera ; the Cerberus and Hydra, with several heads on as many necks; and the warm-blooded Hippocamps and Tritons, whose bodies, destitute of hind limbs, end in cold-blooded fish-an anomaly which already shocked Horace. If they had at least a horizontal tail fin, they might pass for a kind of whale. The cloven-footed Faun is less intolerable; from him our Satan inherited his horns, pointed ears, and hoofs, on account of which Cuvier, in Franz von Kobell's witty apologue, ridicules him as an inoffensive vegetable feeder. The heraldic animals, such as the double eagle and the unicorn, have no artistic pretensions, and their historical origin entitles them to an indulgence they would otherwise not deserve.

It is a remarkable instance of the flexibility of our sense of beauty that, though saturated with morphological principles, our eye is no longer offended by some of these monstrosities, such as the winged Nike and the angels; and

it would perhaps be pedantic, certainly ineffectual, to entirely condemn these traditional and more or less symbolical figures, though in fact the greatest masters of the best epochs have made very slight use of them. There are, however, limits to our toleration. Giants, as they occur in our Gigantomachia, with thighs turning half-way down into serpents, which consequently rest, not upon two legs, but upon two vertebral columns ending in heads and endowed with special brains, spinal cords, hearts, and intestinal canals, special lungs, kidneys, and sense-organsthese are, and always will be, the abhorrence of every morphologically trained eye. They prove that, if the sculptors of Pergamon surpassed their predecessors of the Periclean era in technical skill, they were certainly second to them in artistic refinement. Perhaps they should be excused on the plea that tradition bound them to represent the giants with serpent legs. The Hippocamps and Tritons, with horses' legs and fish-tails, which disfigure our Schlossbrücke, date from a period in which classical taste still reigned supreme, and morphological views were still less widely diffused than at present. Let us therefore pardon Schinkel for designing or at least sanctioning them, as well as the winged horse and griffin on the roof of the Schauspielhaus, for which he must also be held responsible. But our indignation is justly aroused when a celebrated modern painter depicts with crude realism such misshapen male and female monsters wallowing on rocks, or splashing about in the sea, their bodies ending in fat shiny salmon, with the seam between the human skin and the scaly cover scantily disguised. Such ultramarine marvels are worshipped by the crowd as the creations of genius; then what a genius Höllen-Breughel must have been!

Curiously enough, the inhabitants of the caves of Périgord, the contemporaries of the mammoth and musk-ox in France, and the bushmen whose paintings were discovered by Prof. Fritsch, only represented as faithfully as possible such animals with which they were familiar; whereas the Aztecs, a people of comparatively high civilization, indulged in fancies of more than Eastern hideousness. It would almost appear as if bad taste were associated with a middle stage of culture. With regard to the teaching of anatomy in schools of art, the above proves that it should not be confined to human osteology, myology, and the doctrine of locomotion alone, but that it should also endeavour-and the task is not difficult-to familiarize the student with the fundamental principles of vertebral morphology.

Botanists should in their turn point out such violations of the laws of the metamorphosis of plants as must, no doubt, frequently strike them in the acanthus arabesques, palmettos, rosettes, and scrolls, handed down to us from the ancients. From obvious reasons, however, these cannot affect them as painfully as malformations of men and animals, being in themselves repulsive to natural feelings, would the comparative anatomist. Moreover, a beneficial revolution has recently taken place in floral ornament. The displacement of Gothic art by the antique during the Renaissance had led to a dearth of ideas in decorative art. The rich fancy and naïve observation of nature, displayed upon the capitals of many a cloister, had gradually given way to a fixed conventionalism, no longer founded on reality. Rauch, at Carrara, in search of a model for the eagles on his monuments, was the first to turn to a golden eagle, accidentally captured on the spot, instead of to one of the statues of Jupiter. It was then that, towards the middle of the century, decorative art began to shake off its fetters, and, combining truthfulness with beauty, returned to the study and artistic reproduction of the living plants with which we are surrounded. In this respect the Japanese had long ago adopted a better course, and to them we have since become indebted for many suggestions. Thus highly welcome additions were

made to the decoration of our homes, and the ornaments of female dress.

In one direction, however, it will be observed that men of science readily dispense with a strict observation of the laws of nature in art, at the risk of being charged with inconsistency. In works of art, both ancient and modern, flying and soaring figures occur in thousands. These, no doubt, sin against the omnipotent and deeply felt laws of gravity quite as much as the most loathsome creations of a depraved imagination against the principles of comparative anatomy, familiar only to a few adepts. Nevertheless they do not displease us. We prefer them without wings, because wings are contrary to the type, and could be of no use to them without an enormous bulk of muscle. But we do not mind the Madonna Sistina standing on clouds, and the subordinate figures kneeling on the same impossible ground. "Ezekiel's Vision" in the Palazzo Pitti is certainly less acceptable. But to quote modern examples, Flaxman's "Gods flying to the aid of the Trojans," or Cornelius's Apocalyptical riders, and Ary Scheffer's divine Francesca di Rimini, with which Doré had to enter into hopeless competition, are not the less enjoyable because they are physically impossible. We do not even object to Luini's representing the corpse of St. Catharine carried through the air by angels, or to that of Sarpedon, in Flaxman's drawing, by Sleep and Death.

In an interesting lecture on the "Physiology of Flying and Soaring in the Fine Arts," Prof. Exner endeavours to explain why illustrations of men and animals in this condition, though impossible and never visible in real life, strike us as familiar and natural. I do not profess to agree entirely with the solution which he appears to prefer. His idea is, that our sensations in swimming, and the position in which we see persons above us in the water when diving, are similar to what we would experience in flying. Considering what a short time the art of swimming has been generally practised by modern society, especially by ladies, who nevertheless appreciate flying figures just the same, doubts arise as to the correctness of Prof. Exner's explanation. To attribute the feeling to atavism in a Darwinian sense, dating from a fish-period in the development of man, seems rather far-fetched. And do not the sensations and aspect of a skater come much nearer to flying or soaring than those of a swimmer? Another remark of Prof. Exner, which had also occurred to me, appears more acceptable. It is, that under especially favourable bodily conditions we experience in our dreams the delicious illusion of flying. For

"in each soul is born the pleasure
Of yearning onward, upward, and away,
When o'er our heads, lost in the vaulted azure,
The lark sends down his flickering lay,
When over crags and piny highlands
The poising eagle slowly soars,

And over plains and lakes and islands
The crane sails by to other shores." 1

Who would not long, like Faust, to soar out and away towards the setting sun, and to see the silent world bathed in the evening rays of eternal light far beneath his feet? And when we long for anything, we love to hear of it, and to see it brought before us in image. Our desire to rise into the ether, and our pleasure in "Ascensions" and similar representations, are further enhanced by the ancient belief of mankind in the existence of celestial habitations for the blessed beyond the starry vault; a belief which Giordano Bruno put an end to, though not so thoroughly but that we are constantly forgetting how badly we should fare, were we actually to ascend into those vast, airless, icy regions, which even the swiftest eagle would take years to traverse before alighting on some probably uninhabitable sphere.

We are now inclined to reverse the question, and to • Translation of Goethe's "Faust," by Bayard Taylor.

ask: What have sculpture and painting been able to do for science in return for its various services? With the exception of external work, such as the representing of natural objects, not much else than the results obtained by painters as to the composition and combination of colours, which, however, have not exercised as strong an influence on chromatics as music on acoustics. It is known that the Greeks possessed a canon of the proportions of the human body, attributed to Polycletes, which, as Prof. Merkel recently objected, unluckily only applied to the full-grown frame, to the detriment of many ancient works of art. The blank was not systematically filled up till the time of Gottfried Schadow. This canon has since become the basis of a most promising branch of anthropology-anthropometry in its application to the human races.

If the definition of art were stretched so far as to include the power of thinking and conceiving artistically, then indeed it would be easy enough to find relations and transitions between artists and philosophers, though, as we remarked at the beginning, their paths diverge so completely. But it is not so certain that natural science would necessarily be benefited by an artistic conception of its problems. The aberration of science at the beginning of this century known as German physiophilosophy owed its origin quite as much to æsthetics as to metaphysics, and the same erroneous principles guided Goethe in his scientific researches. The artistic conception of natural problems is in so far defective, as it contents itself with well-rounded theoretical abstractions, instead of penetrating to the causal connection of events, to the limits of our understanding. It may suffice in cases where analogies are to be recognized by a plastic imagination between certain organic forms, such as the structure of plants or vertebrate animals; but it fails altogether in subjects such as the theory of colours, because it stops short at the study of what are supposed to be primordial phenomena, instead of analyzing them mathematically and physically. Prof. von Brücke subsequently, by the aid of the undulatory theory, traced to their physical causes the colours of opaques on which Goethe founded his theory of colours, and which to this day have tended rather to darken than to enlighten certain German intellects. The difference between artistic and scientific treatment becomes very evident in this example.

Nevertheless, it cannot be denied that artistic feeling may be useful to scientific men. There is an æsthetic aspect of experiment which strives to impart to it what we have termed mechanical beauty; and no experimenter will regret having responded to its demands as far as was in his power. Moreover, the transition from a literary to a scientific epoch in the intellectual development of nations is accompanied by a tendency to brilliant delineation of natural phenomena, arising from the double influence of the setting and the dawning genius. Instances thereof are Buffon and Bernardin de Saint-Pierre in France, and Alexander von Humboldt in Germany, who, to his extreme old age, remained faithful to this tendency. In the course of time, this somewhat incongruous mixture of styles splits into two different manners. Popular teaching preserves its ornamental character, while the results of scientific research only claim that kind of beauty which in literature corresponds to mechanical beauty. In this sense, as I long ago ventured to indicate here on a similar occasion, a strictly scientific paper may, in tasteful hands, be made as finished a piece of writing as a work of fiction. To strive after such perfection will always repay the trouble to men of science; for it is the best means of testing whether a chain of reasoning, embracing a series of observations and conclusions, is faultlessly complete.

And this kind of beauty, which often graces, unconsciously and unsought for, the utterances of genius, will no doubt be also found to adorn Leibnitz's writings.

CHRONOPHOTOGRAPHY, OR PHOTOGRAPHY AS APPLIED TO MOVING OBJECTS.1 THIS subject forms the basis of a very interesting article, in the Revue Générale des Sciences, by Prof. Marey, who explains a new method for the analysis of the movements of various bodies that are under consideration, more especially in biological than in physical science. Our readers may remember a book that appeared in the year 1882, entitled "The Horse in Motion," published under the auspices of Leland Stanford. Mr. Stanford, wishing to study the relative positions of the feet of horses in rapid motion, employed Mr. Muybridge, who was then noted as a very skilful photographer, to carry out a series of experiments. The success which rewarded their endeavours revealed so much that seemed of importance, that he determined to make a complete study of the subject, and with this intention employed Dr. J. D. B. Stillman, to whom he intrusted the undertaking.

The method the last mentioned adopted was very similar to that employed later by Mr. Muybridge, the differences being that he only made use of one series of cameras, and that the plates were exposed by the breaking of threads by the moving object. The revolving disk was also in vogue then, for taking movements of running dogs, flights of birds, &c., only it was not used to obtain the movements of the horse, as it was found extremely difficult to set the apparatus in motion at the exact moment required, and to regulate it to the speed of the horse.

It is important, next, to refer to the results obtained by Mr. Muybridge in his later experiments, carried out at the University of Pennsylvania, which were published in a large book containing all the series of photographs. The following is a brief account of the method he used.

It consisted in the employment of three batteries, each containing twelve cameras. The object of working with three batteries was to enable him to obtain photographs from three points of view simultaneously, and the manner in which he arranged them was as follows. One battery was set parallel to the track along which the object to be photographed moved, so that its image would be formed on each plate successively as it passed before the lenses; and since the distance between the object and each camera was constant, only one focus was required. Placed at right angles to this track, and directed up and down it, were fixed respectively the two other batteries, and the cameras in these were so adjusted as to have in their field of view the same series of positions as seen in the first battery, only of course from two different standpoints; but since in this case the distance between the object and the cameras was always varying, each of the latter had to be specially adjusted for its own focus.

The instantaneous shutters of all the cameras were connected by wires to a set of twelve metal studs situated on the circumference of a disk, each stud being fastened to a set of three wires, each of which comes from the first camera in each battery, the second set from the second cameras, and so on.

A second disk, placed close by, and carrying a brush, was made to rotate, the brush coming in contact with each of the studs in turn. By this means, a series of currents was sent to these groups of three cameras intermittently; and, as each contact was made, three shutters were simultaneously released-one in each of the series -giving a group of three synchronous pictures of the object that was moving on the track, showing the fore, hind, and lateral views.

One of the first attempts of Prof. Marey consisted in placing on each foot of the moving animal elastic cushions, which were connected with a chronograph by

We are obliged to the editor of the Revue Générale des Sciences for permission to use the illustrations reproduced in this article.

means of flexible tubes. As each foot came in contact with the ground, a record of the impact was obtained, from which interesting results were deduced relating to the peculiarities of the succession of steps, and the timeintervals separating them.

Having referred above to the earlier experiments, we will now mention the very recent work carried out by him. The method that he here adopts differs considerably from his first endeavour, and also from that employed by Muybridge and Stillman. Instead of using many cameras, and therefore many plates, he works with one camera and one plate, and it is on this plate that he produces his series of photographs. The objects that he wishes to study move in front of a dark background, which is situated directly opposite the camera. Fitted to the camera is a large disk with openings in it, and which is capable of quick or slow rotation in a vertical plane.

During the passage of one of these openings before the lens, the moving object has its image cast on the photographic plate, and is there recorded: as soon as the aperture has passed, no light can fall on the plate unti the next opening comes opposite. As soon as this arrives. another picture is taken in the same way, but, during the interval that has just elapsed, the object, having changed its place, forms its image naturally on another part of the plate. By continuing this process, one can easily see that, on the plate being developed, a series of successive images will be seen extending from one side to the other.

With a very slow-moving object, this method cannot be applied so well, unless an intermittent rotation be given to the disk, as we should have a series of overlapping images quite undistinguishable from one another. The following illustration (Fig. 1) is an example of a

picture obtained by using a continuously revolving disk. Between each exposure it will be seen that the horse has not even travelled its own length, but only a little over half, so that the mingling of all the images results in a picture that is useless for purposes of study. The question which was raised from such results as shown in the above figure may be formulated thus: How is it possible to reduce the surface of the object, and yet be able to record the movements of its principal members photographically? The following very artful device, which is shown in the next illustration (Fig. 2), exemplifies the manner in which Prof. Meyer solved the question. By dressing the object in black, employing a dark background, and placing on the members, the movements of which he wished to investigate, white lines and spots, he was able to increase the number of exposures per second without introducing overlapping, and to record the successive positions taken up by them.

We must mention here that the experiments were only carried out with a man as object; if a horse had been taken, it would have been necessary to have dressed it in black, and to have put the distinguishing marks on either one of the fore or hind legs, and not on both at once; otherwise there would have been two complete series of images recorded on one plate at the same time, and overlapping each other.

In another illustration we have an interesting set of attitudes assumed by a running man dressed in this costume

being photographed in a given time is very largely increased, while the overlapping is only slightly apparent. Another case is that shown in Fig. 4, which represents a man jumping. The several phases of movement are here also well discernible, and the images were recorded at the rate of twenty-five per second.

Although the method employed above suited admirably for such purposes as we have mentioned, yet Prof. Marey found that he could not use it without modification for all the cases to which he wished to apply it. The apparatus which he then constructed, and of which a complete detailed account is given in his article, is shown in Fig. 5, and

FIG. 2-Man dressed in black, an i consequently invisible when passing before a dark background. The white lines which are shown on his arms, legs, and on the sole of one foot are the only parts the successive phases of which can be recorded.

(Fig. 3). The lines in the figure indicate the sequence of positions in which the above-mentioned distinguishing

FIG. 3.-Images of a runner, showing the white marks which represent th attitudes of the principal members. Chronophotography on a fixed plate.

differs in many particulars from the former one, the chief characteristic about it being that films are employed which are capable of rapid lateral movement. By means of this moving film it is possible to obtain, in a very short space of time, a large number of separate pictures, for, during each exposure, a new part of the film is brought opposite the lens of the camera, held there, and then slipped along. The apparatus itself is of a most ingenious construction, and the three most important parts consist of a driver, a clamper, and an elastic arm.

In the figure, L represents the driver, and it is due to its action that the motion of the paper is produced; it consists of a wooden cylinder, the surface of which is covered with india-rubber, and round which the band of

marks are found at each exposure; and the resulting diagram also shows that the number of images capable of

paper passes when made to travel from one bobbin to the other.

In the case of the clamper, marked c' in the drawing, its action is to press the paper against the side of the chamber during each exposure, and this is carried out by means of a series of cams placed on a small circular horizontal disk (marked C). It might be supposed that, with very short exposures obtained by means of a very rapid shutter, the clamper would be found quite unnecessary, as the horizontal distance traversed by the band of paper during an exposure would be practically nil, or at any rate small enough to produce no visible effect on the

lodoce, . . . passing on to scorpions and spiders, and then to shrimps, lobsters, . . ."

Although, at the first glance, one cannot quite see how Muybridge's principle, or, at any rate, a slight change of it, could be applied to interpret the gait of the centipede, yet in Prof. Marey's instrument Prof. Lankester will, we hope, find just the kind of apparatus to carry out the various suggestions to which he referred. In fact, the instrument has already been employed in producing pictures representing aquatic locomotion, and the follow

picture produced; but this is not the case, for Prof. Marey says that by experience the only good images obtainable were made with the use of the stop.

Owing to the quickness of the action of the driver, and the instantaneous blow given by the clamper to the paper at each exposure, an elastic arm is made to come into play to relieve the paper of any strain or force to which it may be subjected.

Many readers may remember the very interesting

ing illustration (Fig. 6) shows a Medusa swimming, while Fig. 7 shows the phases of movement that a star-fish undergoes in order to turn itself over.

The interesting point is displayed in the last four pictures of the series. Counting from the bottom, No. 5 shows the position just before one of his "rays" leaves the ground and just when he begins to grip it with the other two; having this grip, he is able to dispense with the use of the other ray, and so raises the other three as

article in a former number of NATURE (vol. xl. p. 78), written by Prof. Ray Lankester, relating to the Muybridge photographs. Towards the end he says: "For my own part I should greatly like to apply Mr. Muybridge's cameras, or a similar set of batteries, to the investigation of a phenomenon more puzzling even than that of 'the galloping horse.' I allude to the problem of 'the running centipede." He then goes on to say: "I am anxious to compare with these movements the rapid rhythmical actions of the parapodia of such Chatopods as Phyl

shown in No. 6. No. 7 illustrates the position of unstable equilibrium as obtained by means of the preceding movements, while the last one exemplifies stable equilibrium again.

The time occupied in the above evolutions is not so short as may be supposed, but lasts sometimes from ten to twenty minutes, the intervals in time between two of the above pictures being about two minutes.

The movements of the eel have also been studied in this way, and the series of movements represented in