490 



THE EXTERIOR OF THE HORSE. 



With the aid of distinguishing marks applied upon the body over the artic- 

 ular centres, and united afterwards on the proof by straight lines, they have 

 succeeded in obtaining the images of the diverse positions of the locomotory 

 segments during the evolution of the members, as well as the exact trajectory 

 of the centres of movement (Fig. 183). 



Fig. 183.— Movement of the anterior member of the horse. 

 (Obtained by means of chronophotography.) 

 A. Phase of contact. | B. Phase of elevation. 



This achievement is significant. It not only permits us to determine with 

 great accuracy the limitary positions of flexion and extension and the field of oscil- 

 lation of the osseous levers in the rapid motors, but it also opens the way to the 

 discovery in the future of the scientific theory of locomotion, which has been so 

 ably treated in the splendid works of the Weber brothers. All the investigations 

 undertaken in this direction will be rich in facts of inestimable value to those 

 who pursue the rational study of animal mechanics. 



For ordinary requirements, however, chrono-photography can be greatly 

 simplified, and thereby rendered intelligible and accessible to the greatest num- 

 ber of individuals. All that this method need do is to record, always at equal 

 intervals of time, the principal attitudes characteristic of a given gait. The 

 images, in this manner, being less numerous, the ultimate results will be less 

 confused. Instead of remaining contented with the axes of movements of the 

 bony segments, we shall be enabled to obtain true portraits, as true to nature as 

 those of Anschiitz, and quite as valuable to the scientific man as to the artist. 



Systems of Notation of the Gaits. 



In order to interpret in a clear and simple manner the indications, at times 

 very complicated, furnished by the registering apparatus, we make use of con- 

 ventional symbols which represent the rhythm of the beats, the duration of the 

 contact with the ground, the mode of association of the members, etc. These 

 symbols, altogether comparable to those which are employed in music to repre- 

 sent the sounds and their intervals, constitute, by their mode of combination, 

 what is conventionally called the notation. 



