12 Gait of, the American Trotter and Pacer 



is more likely to be found in the line trot, which we must assume as 

 being the ideal locomotion. 



All our investigations of such motion, whose record is left on 

 the ground, should be made on an even surface of such a nature as 

 the tracks of this country present. The ground should be harrowed 

 or raked by hand, leaving a surface of fine loose earth on top, just as 

 a fast and safe track is generally kept. 



We must base such investigations on this even surface so that un- 

 evenness of gait is not due to roughness of ground, but to the causes 

 which we wish to ascertain. Ordinarily the greater the distance meas- 

 ured the better will be the results, but all the way from 10 to 20 strides 

 will show the ,gait well enough. Horses at a fair speed and according 

 to the nature of the gait will stride from 16 to 21 feet with each leg 

 as they fly through the air from one imprint to the next. I have al- 

 ways taken 20 strides as my basis of calculations, because, firstly, the 

 distance is long enough to show repetition of faults, or rather the varia- 

 tions from the average ; and, secondly, because the simple decimal num- 

 ber is easy to divide with in the calculations. We shall, therefore, re- 

 quire a stretch of from 360 to 420 ft. 



The second important requirement of such an investigation is an 

 even rate of going when trotting over this stretch with the horse at 

 speed. The line so taken should also be as straight as possible ; but 

 ordinarily both these requirements are fulfilled because of the nature 

 of the trial, which is but a piece out of a quarter or half mile. We 

 may safely assume that if the speed is not uniform or the line straight, 

 this is due to the very causes we intend to investigate. Averages and 

 variations tell a truthful tale just the same. 



Let us imagine that all these preliminary conditions are estab- 

 lished and we look at the tracks of the horse just driven over that 

 piece of ground. 



There will be the record on the ground as given in Fig. 2. We 

 know that in the trot two diagonally opposite feet move at the same 

 time. Let us call them the correlated feet, because of their similar 

 extension and action at the same time. In Figs. 7, 8 and 9 we have 

 these correlated feet at rest, in a slow walk and in a trot. The fall of 



