44 



ANIMA.L LOCOMOTION. 



are teclmical expressions, and apply to the left and right 

 sides of the animal. Another point to be attended to in 

 examining the figures in question, is the relation which 

 exists between the fore and hind feet of the near and 

 off sides of the body. In slow walking the near hind foot 

 is planted behind the imprint made by the near fore foot. 

 In rapid walking, on the contrary, the near hind foot is 

 planted from six to twelve or more inches in advance of the 

 imprint made by the near fore foot (fig. 21 represents 

 the distance as eleven inches). In the trot the near hind foot 

 is planted from twelve to eighteen or more inches in advance of 

 the imprint made by the near fore foot (fig. 22 represents the 

 distance as nineteen inches). In the gallop the near hind foot 

 is planted 100 or more inches in advance of the imprint made 

 by the near fore foot (fig. 23 represents the distance as 110 J 

 inches). The distance by which the near hind foot passes 

 the near fore foot in rapid walking, trotting, and galloping, 

 increases in a progressive ratio, and is due in a principal 

 measure to the velocity or momentum acquired by the mass 

 of the horse in rapid motion ; the body of the animal carrying 

 forward and planting the limbs at greater relative distances 

 in the trot than in the rapid walk, and in the gallop than in 

 the trot. I have chosen to speak of the near hind and near 

 fore feet, but similar remarks may of course be made of the 

 off hind and off fore feet. 



" At fig. 2 3, which represents the gallop, the distance 

 between two successive impressions produced, say by the near 

 fore foot, is eighteen feet one inch and a half. Midway 

 between these two impressions is the mark of the near hind 

 foot, which therefore subdivides the space into nine feet and 

 six-eighths of an inch, but each of these is again subdivided 

 into two halves by the impressions produced by the off fore 

 and off hind feet. It is thus seen that the horse's body 

 instead of being propelled through the air by bounds or leaps 

 even when going at the highest attainable speed, acts on a 

 system of levers, the mean distance between the points of 

 resistance of which is four feet six inches. The exact length 

 of stride, of course, only applies to that of the particular horse 

 observed, and the rate of speed at which he is going. In the 



