Birmingham state herald., 1896-03-01
THE CHRONO-PH PHOTOGRAPHY Wonders That Have Been Ac- compIished by Means of It. OLD THEORY ABOUT LANDING When Jumping From Height Disprosed.
 Motion of a Person Analysed by
 Clock-Work Apparatus.
New York Journal.

New York Journal.
 Fifteen years ago everyone was talk ing about the photographs of the horse in motion taken by MT. Muybridge, un- der the direction of Governor Stanford of California. Recent developments put MT. Muybridgess work in the shadow.
 photography, the process of taking photographs m quick succession, so as to illustrate and measure the path and poses of moving body, has been brought to a higher degree in France than anywhere else. Professor Marcy of the College of France, who has devot- ed years to the oevising of apparatus for the recording of motion, is one of the few scientists in the world who have their own way. Tn the Pare des Princes (on the Rothschild property, near Au- teuil race course, ca the outskirts or Paris) a station has been constructed under Professor Marey's direction, which is as completely arranged for the prose- cutdon of his researches as is an observa- tory for the work of an astronomer. There is a fine. circular track three-quar- ters of mile in length, on which the paces of man and of the larger animals can be examined. Accurate and clear chrono-photography is facilitated by the arrangement of background uniformly illuminated, and the station is supplied with registering instruments of all sorts.
 
 rious animals and the geological speci- mems at the Jardin des Plantes and the Jardin d'Acclimation are freely drawn upon when any other types are desired.
 The work of M. Marcy Is based upon the theory that if serial photography Is combined with mechanical timekeeping all directions of motion and all degrees of speed may be chron.cled. Adding to this registration the information supplied by any of the ordinary instruments for re- 1.<s. manent record of the effort made by any moving creature, and the precise result, in terms of measurement. of that effort. 4 1t is only since M. Marey's station was perfected that mechanical constructors have had the full benefit of the object lessons supplied by animals.
 The locomotion of bipeds and quadru- peds is a process to which the most ex- act observation is profitably employed. MT. Muybridge showed the world how horse picks up his feet and puts them down again, but the way in which the hoof's impact is effected, the distribution of shock and the distribution of impress sion have never been shown before. It is easy to understand that such experi- ments enlighten the veterinary surgeon and the horse shoer but it is surprising to learn that M. Marcy has, by his study of the human foot in motion, proved that our ideas about landing softly when we step down from height are radically
 
 ground with the ball of the foot before the heel. But M. Marcy shows by actual experiment that the shock received in the heel is less injurious to the system than the other.
 Reports that he from time to time com- municates to the Institute of France are always received with great interest His latest publication, "Le Mouvement." summarizes all that has been done in this field of work, not only at this sta ton, but a1c h md hy oil
 The chronographsc shoe is one of the more elementary of the recording instru- ments employed at the station.
 The subject whose motion is to be ana- lyzed carries in his hand box contain ing a clock-work drum like that which is seen on every recording thermometer. and the elastic apparatus in the sole of the shoe transmits each impression to the needles.
 For the analysis of the paces of horse the apparatus is necessarily much more ella borate, and the system of pneumatic tubes shown in the illustration would hardly soothe the nerves of a skittish mare. instantaneous "snapping' of birds on the wing, and one of the prettiest inventions of the age.
 The gun receives, upon the sgelatine plates arranged in a revolving chamber, successive impressions at the rate of twelve every second, so that the twenty five plates in the magazine cover two minutes of the flight of bird whose path the gun follows.
 The more violent and sudden move ments, such as those of a man leaping into the air, call into play all the variants of the scheme of mensuration, and the dynamograph, or force measure, shows just how much. muscular energy is ex- pended in a given jump Even the birds have been harnessed to the car of science, and pigeon hardly conscious of the weight of the tube he carries, leaves so clear track upon the instrument that the movement of the wings can be esti- mated to the tooth part of a second. The whole subject is one of most fasci- hating interest, and 1t is more than like | ly that M Marey's investigations will be l followed up in this country.