492 THE EXTERIOR OF THE HORSE. 



1st. During the first bar, the first sound or beat is given by the anterior right member, AD. 

 which commences its contact ; the posterior right, PD, accomplishes the second half of its rest; 

 the anterior left, AO, commences its elevation ; the posterior left, PO, terminates the second 

 half of its elevation. 



Fig. 185. 



2d. During the second bar, the second beat is given by the posterior left, PG, which com- 

 mences its contact; the anterior right, AD, finishes its contact; the posterior right, PD, com- 

 mences its elevation ; as to the anterior left, AG. it terminates its elevation. 



3d. During the third bar, the third beat is given by the anterior left, AG, which commences 

 its contact; the posterior left, PG, finishes its contact; the anterior right, AD, commences its 

 elevation, while that of the posterior right, PD. is terminated. 



Finally, during the fourth bar, the fourth beat is given by the posterior right, PD, which 

 commences its contact, and that of the anterior left, AG. is terminated; the posterior left, PG, 

 commences its rising, while the anterior right, AD. is reaching the end of this phase. 



The step is completed ; the whole stave is played. Each member has given its note, has kept 

 it up during two bars, and has been silent during the other two. 



During each bar, also, the body has rested on two members : upon the right lateral bipeds, 

 ADIPD (the first bar) : upon the right diagonal, ADjPG (the second bar); upon the left lateral 

 bipeds, AGIPG (the third bar) ; upon the lett diagonal, AGlPD (the fourth bar). 



The beats or sounds of the members have succeeded each other in the following order : AD, 

 PG, AG, PZ;,— that is to say, diagonally, etc. 



All these characters are those of the ordinary walk. A glance over the 

 scheme of its notation suffices to coraijrehend them. 



Whatever may be the combinations of the rhythm of the beats, the dura- 

 tion of the relations and the elevations, the mode of association or succession of 

 the members, this scale will at a glance indicate them in all their modifications, 

 and in a manner clearer and more rapid than can be depicted in ordinary 

 language or writing. In this consists the great superiority of this system over 

 that of Lecoq. 



3d. Notation of M. Marey.' — The method employed by Professor Marey 

 is based upon the same principle as the preceding, although slightly modified in 

 its details. 



First, the notations of the anterior members are placed one below the other ; 

 those of the posterior members are treated in the same manner. This method 

 allows an easier comparison of the bipedal locomotion of man with that of 

 quadruped animals. 



The contacts or periods of the foot touching the ground are represented by 

 the wide lines : the white for the right members and the gray for the left. The 

 phases of elevation, during which the body is entirely in the air, are, on the con- 

 trary, represented by simple intervals. Thus confusion is avoided and the read- 

 ing and interpretation of the phenomena are much simplified. 



Finally, whenever it is possible, the tracings obtained with the registering 

 needles are annexed and superposed to the corresponding notations. 



1 Marey, La machine aniraale, p 147. 



