Record of the Tracks on tJie Ground 61 



A slight curve may be followed in line as it exists in wheel tracks 

 and for practical purposes such a curve does not affect the results 

 seriously, especially if another slight curve in the opposite direction is 

 included in that stretch to be measured. Of course, it always is very 

 desirable that in every trial made the horse should be driven as straight 

 as possible. This cannot always be done and we must be satisfied with 

 a good average showing. 



In Fig. 42 will be seen the main features of a cross section of a 

 horse in motion hitched to a sulky. AB is the ground surface and 

 comprises the width of sulky gauge ; the circle above is the body of the 

 horse with center of gravity at C ; GH and DE are perpendicular lines 

 indicating the moving legs of said horse ; and MN is the vertical plane 



A H N B 



no +2 



parallel with the lines described by A and B, and bisecting or cutting 

 in half said moving horse. . Judging from the mechanical accuracy of 

 construction of the sulky, we may safely assume that the horse travels 

 on lines equally distant from the tracks left by the wheels A and B, 

 and that the median plane MN strikes the ground at a point N midway 

 between A and B. Therefore, for all practical purposes the averages 

 of the distances of the tracks at E and H should be equally distant 

 from N, the median line drawn on ground as suggested. 



These reasonable assumptions or postulates are offered to estab- 

 lish a standard gait and a standard balance, for by such a standard we 

 must judge the deficiencies. 



After a trial over a prepared piece of ground and after the white 

 cord has been staked out as the median line between the tracks of the 



