THE HORSE IN MOTION. 87 



of the last t\vo chapters, the theory may have already outlined itself; 

 but it is desirable that it should be made clear to all, and many of the 

 anatomical facts demonstrated in the last chapters must be taken for 

 granted in this by those who have not given the necessary attention 

 to the anatomical descriptions. Perfect quadrupedal locomotion re- 

 quires uniform support to the centre of gravity and continuous pro- 

 pulsion by each extremity in turn. 



In order to avoid the abstract study of the co-ordination of the 

 limbs in locomotion, figures are given to aid the mind in following the 

 movements. They were executed by a process called photo-engraving, 

 after drawings made with great care from a series of photographs, and 

 represent twelve views of as many positions of a running horse. Three 

 horizontal lines are drawn above the base at intervals of one hand, or 

 four inches, as a guide to the eye in determining the elevation of the 

 feet, and a fourth near tlvj back to show the deviation from a horizontal 

 line of the centre of gravity, which we will suppose to be under the 

 saddle. These cuts are not introduced for their accuracy ; they have 

 been subjected to too much manipulation to lay claim to that precision 

 of outline that will be found in the heliotypes and silhouettes in photo- 

 lithography given in illustration of the paces. 



FIG. i. 



Fig. i. gives the position of the animal in readiness to start, 

 height is a little in excess of sixteen hands. 



Its 



