6 THE EXTERIOR OF THE HORSE. 



Here are, in fact, the results wliich we have obtained by the aid of this procedure upon a 

 saddle-horse of a fine form provided with good equilibrium, that measured 1.55 m. at the withers 

 and at the croup, and 1.53 m. from the point of the shoulder to the point of the buttock. The 

 subject, saddled and bridled, was weighed, the neck at 45 degrees and the head elevated. Its 

 base of support, AB, was equal to 1.20 m. As to the total weight, which was 445 kilogrammes, it 

 was distributed thus : 



Upon the anterior biped 257 kil. {F'). 



Upon the posterior biped 188 kil. (Jf). 



In the particular case of which we are speaking, the point P divides the line AB, which 

 unites the two forces, into two parts inversely proportional to their intensity. We have then 



_F_^PB ^j. _ AB — PA 

 F' PA PA 



By the addition of the denominators to each of the two terms of this equation we obtain 



F+ F' ^ AB — PA + PA ^ AB . 

 F' PA PA ' 



whence 



PA = ELJ^AB ^ 257 X 1.20m. ^ ^gg^ 



F+ F' 445 



and 



PB = 120 m. — 0.69 m. = 0.51 m. 



The line of gravitation then falls upon the horse submitted to the experi- 

 ment at 0.51 m. posterior to the anterior biped. 



This is about the position which MM. Raabe and Bonnal have assigned to it. The line of 

 gravitation'bf the Arab mare upon which these horsemen experimented was situated 0.69 m. in 

 front of the coxo-femoral centre and 0.47 m. from the centre of movement of the shoulder. 

 The distance of its two centres of movement was 1.17 m. instead of 1.20 m. As to its bipeds, 

 they weighed : the anterior, 270 kilogrammes— the posterior, 184. In this case, the distribution 

 of the weight, although analogous to that of our horse, differs from it, since in the latter the 

 surplus weight of the anterior bipeds is only 69 kilogrammes, whilst in the mare it reached 

 86 kilogrammes. The more anterior position of the line of gravity in the latter is thus 

 explained. 



MM. Eaabe and Bonnal have deduced with reason the practical importance 

 of obtaining as precise a determination as possible of the centre of gravity. The 

 ideal to be realized, when we think of placing a dorsal burden upon a horse, 

 should, in fact, consist in distributing this burden upon each biped proportionally 

 to the weight which it bears in the natural state. In these conditions the centre 

 of gravity preserves its normal position and one of the bipeds is never relieved 

 at the expense of the other. 



In 1835, Morris and Baucher ^ had already experimentally determined in the 

 horse the displacements of the centre of gravity, by changing the position of the 

 head and neck, as well as that of the rider. 



"With this purpose," says Morris, " M. Baucher, a horseman, and myself were going to the 

 general mart of the Custom-House at Gros-Caillou to weigli horses upon scales of proportion with 

 movable planks invented a few years ago. . . . 



"The two weighing-machines were placed in such a manner that the anterior extremities 

 rested upon the middle of the first and the posterior extremities upon the middle of the second. 



1 Morris, Essai sur l'ext6rieur du cheval, Paris, 1857, p. 41. 



