518 THE EXTERIOR OP" THE HORSE. 



the contraction is all the greater as the centre of gravity tends to 

 deviate farther from the median line of the body. 



" The vertical or longitudinal displacements cannot be represented," 

 adds Lecoq, " by the two uniform curves which exist in the amble. 

 As the body is elevated by the effort of the members and falls in con- 

 sequence, the centre of gravity should of necessity describe two para- 

 bolic curves, such as CD and DE (Fig. 213), the body falling with 



greater velocity than that with which it is raised, although the effort 

 of propulsion may always be uniform." 



Finally, M. Marey * has been able, with the aid of registering in- 

 struments, to note the reaction, that is to say, the displacements of 

 the withers and the croup at the period of contact of each of the mem- 

 bers upon the ground. Thus he has obtained the curves RA and RP, 

 seen in the upper part of Fig. 209. The reactions of the anterior mem- 

 bers have given the line RA; those of the posterior, the line RP. 

 " Here we see," says he, " that the moment in which the body reaches 

 the lowest limits of its vertical oscillation coincides precisely with that 

 in which the feet are not in contact with the ground. Thus, the period 

 of suspension of the body is not due to the body of the horse being 

 projected in the air, but to, the flexion of all four members for a short 

 period. 2 The maximum height of the rise of the body corresponds, 

 on the contrary, to the termination of the contact of the members with 

 the ground. It seems, from the tracings, that the rising of the body 

 only commences a little after each double beat, and continues during 

 the whole of the contact. 



" Finally, we see, in the same figure, that the reactions of the an- 

 terior members are greater than those of the posterior. This fact has 

 to us appeared constant ; besides, the inequality of the reactions is 

 more exaggerated in the walk, in which the instrument placed upon 

 the withers nearly always shows appreciable reactions, while upon the 

 croup it shows scarcely any." 



Upon the instantaneous photographs from Lissa it is easy to prove 



1 Marey, La machine animal e, p. 162. 



2 Some exceptions in this respect should be made. Instantaneous photographs have given 

 different results, more in harmony with observation of the movements of the rider upon the 

 saddle. 



