CHAPTER IV. 



RECORD OF THE TRACKS ON THE GROUND AND 

 THE IMPORTANCE OF AVERAGES, 



With animals in motion we must ask either the camera or the 

 tracks on the ground for the story of their gaits. What Muybridge, 

 years ago, showed to an astonished world was the profile view of 

 horses and other animals in all stages of motion. While the camera has 

 thus given to the student the key to animal locomotion, it is not always 

 practical to apply its revelations to every case. After having studied 

 the principles of such exact knowledge as photography revealed, 

 and leaving the eye to judge according to such facts, we shall dis- 

 cover the actual condition of a gait only in the record left by the 

 tracks on the ground. While "he who runs may not read" in this case, 

 it may become convincing during the investigation that he who studies 

 a little may certainly read the meaning of this record. 



Muybridge and Roberge have done a great deal to analyze and 

 simplify the motion of the horse, but added to that knowledge should 

 be the study of the tracks for each individual case. This recorded gait 

 on the ground, when reduced to figures by means of the tape-line and 

 by means of simple calculation for general averages and variations, 

 will soon produce order out of chaos and give as clear an idea of the 

 horse's action and extension as is possible to acquire. The main fea- 

 tures of the measurements and calculations are not beyond the reach 

 of any intelligent person, even if all the details of such an investigation 

 as formulated in my small manual books are not fully carried out or 

 computed. 



Many people make much of the so-called stride, or the step the 

 horse takes with each leg. I want to say from the start that the stride 

 for all four legs must be the same ; that is, the stride of a certain gait 



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