98 THE HORSE IN MOTION. 



The order and action of the limbs are uniform in all the numerous 

 trials of running horses photographed at Palo Alto ; so that it may b 

 considered that they are in conformity with a law. Five series of th 

 photographs are given, of horses representing different rates. Th 

 first is that of "Mohammed," whose stride is 15 ft. 9 in.; and the 

 last, that of " Florence Anderson," with a stride of 20 ft. 6 in. All of 

 them were going at a moderate rate. The numbers, and correspond- 

 ing lines on the ground, indicate spaces of one foot ; and as the pho- 

 tographs were taken in succession at the same intervals, they will 

 be understood to show the position of the limbs at each interval of 

 one foot. The position of the camera is indicated by the direct line 

 on the ground, and is that of the observer. In the last series the 

 gauge line shows how little the centre of gravity is deflected in its 

 trajectory from a direct line, and this line will be found to vary least 

 when the speed is the greatest. By the aid of these lines and their 

 figures the reader may be able to measure the strides and parts of 

 strides, and determine their respective intervals. 



It has been observed that there is not perfect regularity in the line 

 of the footprints of a running horse, especially if the ground is uneven. 

 This is owing to the variations of the centre of gravity, which compel 

 the corresponding variations of the positions of the small base which 

 supports it ; through an instinct of the same kind which we recognize 

 in ourselves, and make use of when we fail to give proper attention to 

 the ground on which we are walking and govern the movements of 

 our feet accordingly. This we do not always do, and the effect is to 

 cause us to stagger even when we are sober. This instinct must be 

 regarded as existing in a higher degree in a horse, as his locomotive 

 apparatus is more complicated and of a higher order than that of man. 



If the reader is interested in knowing how far this law of the mech- 

 anism of running holds, he may follow it in the succeeding plates. 

 He will see the same movement in the greyhound, Plates XVIII., 

 XIX., and in Plate XX. two hounds running at unequal rates of 

 speed. It is the same in the ox running, Plate XXL, and has been 

 proved true of the goat, and will be found to hold true of all those 

 quadrupeds whose four limbs are of like proportions. 



