THE HORSF. IN MOTION. 89 



becomes nearly straight, and the pastern bone resumes its position 

 under the metacarpus, or cannon bone, and while that joint is still 

 supported at its convex posterior surface by these powerful ligaments ; 

 and as the limit of extension is reached and the limb is at an angle 

 with the ground of forty-five degrees, a vigorous concerted action of the 

 propellers sends it forward and upward in the direction of the axis of 

 the limb with a force so great as to close the space between the croup 

 and the gauge line above it, and all his feet are in the air. If this force 

 had been applied, as is popularly supposed, by the posterior extremity 

 and behind the centre of gravity, the result would inevitably have been 

 to pitch the animal headlong to the ground. The position of the fore 

 leg just before it leaves the ground is best shown in Fig. 12. 



FIG. 3. 



Fig. 3 shows the feet all in the air. The foot which rested last 

 upon the ground is now eleven inches above it and moving rapidly 

 to the front. The interval of time between the photograph of the 

 horse in position No. 2 and that of No. 3 was greater than that which 

 passed between No. 3 and No. 4, owing to want of uniformity in the 

 tension of the threads making the magnetic circuit. This defect was 

 subsequently remedied ; and in the series of views illustrating the run, 

 in which the gait was more thoroughly analyzed by a larger number 

 of cameras, the intervals are very regular. 



