Capt. J. B. Dumas, at our request, has been kind enough to send us a very interesting note upon the method that he employs in his teaching at the High Riding School. We reproduce it : My object, says he, has been to realize by a succession of images that photography renders indisputable a monograph annotated, figure by figure and point by point, with all the gaits and all the paces of the High School. Placed in the center of the arena with my pupil, I secure by photography the precise time that his inexperienced or powerless eye has not completely seized. I make him see it; I explain it to him: (1) from the view point of quadrupedal locomotion ; and (2) from the more important view point, of the use of the horse for riding. These lessons do not go without a com lete revision of all the existing works upon locomotion passed through the sieve of a very long experience with the horse and completed by entirely new researches. I wish to say that I was the first to study and point out the influence that declivities exert upon the gait of the horse that moves thereon. I have deduced therefrom two rules : tendency to a lateralization of the gait in descents and a tendency to diagonalization in ascents. The conclusions are deduced of themselves to the end of improving the gaits of lateral form and those of diagonal form. I have, in fact, made a thorough comparison of the pace and the gallop, and concluded that, as regards forms and the kind of equilibrium engendered, these two gaits are sisters, and, all other things in time and space being equal, produce identical results in the emphasizing of the supercharge of the shoulders and the bearing down of the horse. These are the gaits of lateral form. On the contrary, I have found that the gaits of diagonal form, such as the trot, ease and raise the horse by facilitating the transfer of the weight to the hind quarters. These are two points to be noted and borne in mind in training, according to th e individuali ties considered ( man or horse) and th e necessities to be satisfied. Finally, the beginning and end of all my system of training is summed up in one rule of the simplest character, in one sole principle for the rider : Act with the leg on the same side and at the same time as the anterior of the animal that is posing, the end of the horses nose pointing in the direction of the motion to be begun. This is as mnch as to say : require of the animal an oblique or lateral motion only when his anterior, raised in the direction of the motion to be begun, permits him to execute it. This corresponds to the instruction given the foot soldier : turn on the side of the anterior raised or carry the weight of the body upon the leg that does not begin the motion, and carry it afterward in the direction of such motion, in order to extend and amplify it. This simple rule leads to correct turns without resistance or revolt, to the Spanish pace, to the prance, to starts at a correct gallop, etc., and, in a word, to correct riding in all the gaits and paces of the High School, and to the rapid training of the horse. We accompany this interesting dissertation with some specimens of the photolithographs that illustrate the Album de la Haute Ecole, recently published by Captain Dumas and Viscount Ponton dAmercourt. Figs. 1 and 2 reproduce exercises that are very difficult of execution, and which denote great skill upon the part of the rider. Figs. 3 and 4 show times of the great elongated trot and the racing gallop. Fig. 5 gives the work upon a declivity, useful to Alpine hunters. Fig. 6 snows the cabriole, an exercise that can be performed only by first-class riders. We shall now examine with the authors one question, and that is the utility that these documents present from the view point of the artistic reproduction of animals in motion. An experienced eye succeeds in seizing the impression of an action whose duration is not less than one-sixth of a second. Further, in order to succeed in this right along, it is necessary for it to have recourse to the utilization of the luminous impression upon the retina. The observer should attentively follow with his eye the horse in motion at a distance of 100 or 150 meters, and then, immediately after the rapid execution of the time of the motion that he desires to studv, he should abruptly close the eyes. The organs of external sight, had he not thus momentarily arrested their operation, would have continued to register the different periods of the acts of locomotion in measure as they were executed while rendering account of themselves to the mind, so to speak, only every sixth of a second ; that is to say, in grouping them more or less. It would, therefore, have been able to succeed in seizing a clear image of the de-composi tion of the m o tion ; but the retina, owing to | the persistence of the luminous impression, momen tarily preserves the interior registering of the last act that strikes it, and the observer will be easily able to find this vision there. At the same distances of observation, or at distances that may be less, photography, on the contrary, very exactly retains the definition of a movement that is executed in less than one twenty-five thousandth of a second, if need be. It results that, with respect to the latter, the human mind scarcely conceives of anything more than a union of motions—a synthesis, because the instrument at its service, the eye, permits it to see merely a grouping and not to decompose them habitually. Besides, the education of the eye by the works of the majority of painters and sculptors, almost all of whom still work upon conventional types as yet little studied, causes it to retain and understand merely conventions as destitute of truth as a representative alphabetical character could be. Photography, on its side, registers an analysis that takes from the imagination all idea of a motion in course of execution, since the exact conception of the latter can result only from a limited succession of true positions, fused by art into a single image. As regards the definition of the motion by the image, the eye and photography, therefore, see equally false; the first, the eye, the tool of synthesis, because, in the first place, it sees badly for want of education and training, and, second, because it sees at once too large a number of successive phases in the series of a same motion, and mixes them with each other; the second, the analyst. that is to say, photography, because it sees too quickly, and consequently seizes at once too little of the series of tbis same motion to allow the human mind to afterward see in these images a close relation with what the eye has made it see. It will be concluded from this that the representation of very rapid motions, which our eye sees badly, should, in order to be true from the view point of the human mind, take account of the manner of seeing and the eyes capacity for registering, as well as of the precise data furnished by photographic analysis. A fusion between these documents, under the dominant idea that they are destined to be appreciated by the human eye, is therefore necessary, and it is here that art must intervene. Photography will furnish the latter simply, with documents of exploitation, data whose strict reproduction would be as false from the view point of the eye as ugly from the view point of art. But we must hasten to add that the human eye, imbrued for centuries by the works of artists and by itself, if it preserves a just feeling of what is adapted to it, has not yet obtained its education. It now likes and appreciates only the illusions concordant with the conventions that it knows, that it has alone retained and that it believes in good faith to see and to find again in reality. It is therefore necessary to train it and exercise it to see more accurately, more truly, and art must impose its rule, so that new and true synthetic conventions shall finally replace the ancient and false ones. The reproduction, by quadrupeds in motion, of the figures that the latter have engendered will always, in fact, present for the majority of them the capital defect of corresponding to none of the times of any motion whatever and of being materially irreal-izable. It may therefore be foreseen that the simple types that art will retain for the representation of gaits will result from complete knowledge, and then from the fusion of the images in series furnished by photography. In its study of nature, it will take them as guides for better interpreting the acts of motion.— La Nature. Fires in Sky Scrapers. At a recent fire the Chicago firemen demonstrated at the Masonic Temple their ability to cope with fires in the upper stories of the tallest buildings. Engine No. 1 of the city fire department pumped a stream of water through 500 feet of hose and standpipes to the roof of the building, where there was sufficient force to drench the roofs of neighboring buildings. The waterpressure at the engine was 240 pounds. On the roof at the same time the pressure was 54 pounds to the inch. The length of the standpipe from the ground to the roof of the Masonic Temple is 323 foet. The sight of an engine and firemen at this sky scraper attracted a crowd of people who were well soaked for their curiosity. The result of the test was gratifying to Chief Swenie of the Fire Department and to the insurance men present. Cracked by Earthquake. One effect of the recent earthquake in Cincinnati and the surrounding country is just coming to light. Notwithstanding the recent heavy rains, it has been discovered that many cisterns are still as empty as during the long dry spell. Investigation shows that the cement was cracked in hundreds of cisterns, rendering them practically worthless.