Record of the Tracks on the Ground 41 



is, say, 18 ft. That means that each leg strides that distance. One 

 leg may vary more than another leg, but in the sum total the average 

 for each leg's stride must be 18 ft, or else the horse will break into a 

 run and cease trotting or pacing. To get at the stride of a particular 

 gait, or of any horse at any speed, we must, therefore, measure the 

 whole distance of such a trial, and compute from this the stride of each 

 leg. If for convenient calculation we choose 20 strides for each leg 

 as sufficient to indicate peculiarities of gait, we have for the average 

 this total of 20 strides divided by 80. This is the average stride for 

 that horse at that particular gait. 



There are, however, irregularities of gait which are caused either 

 by bad or indifferent shoeing or by a faulty anatomical structure in 

 one or more limbs, such as a shorter leg, a club foot, etc. Such de- 

 ficiencies in stride are found by this method to consist of variations 

 in stride. The disturbing leg falls short of average stride, and when 

 recovering lost ground exceeds such average. The absence of exces- 

 sive variations in the strides has a great deal to do with the regularity 

 and evenness of gait. Later on we shall see that the variation from 

 average, in the fore and hind legs, has a different meaning respectively 

 in fore or hind extremities. 



The variations lead us to the question of extension; for, where 

 the variations are different between either the two fore or the two 

 hind legs, there must of necessity be a different extension or placing 

 forward of foot. With almost all trotters or pacers the same habit 

 prevails as with the runner, and that is, one foot is preferably put a 

 little ahead of the other in front ; but this extension of one fore ahead 

 of the other has as a consequence the simultaneous extension of hind. 

 In other words, an irregularity in front is likely to cause one behind, 

 because of the intimate relation between fore and hind legs. In the 

 trot it will be the hind foot of opposite side, and in the pace the hind 

 foot of the same side. As the difference of extension between the hind 

 legs becomes greater, the danger of interference with fore legs in- 

 creases. Fig. 30 will illustrate the points here raised for the trot and 

 Fig. 31 for the pace. If, for instance, in the trot, the fore foot A is 

 with preference placed ahead of fore foot B, it follows that the hind 



