SPEED IN LEA PING. 1 3 3 



his hocks or buttocks to his muzzle) of body to carry over 

 a fence, independently of raising it to a sufficient height ; hence 

 his high jump partakes much more of the long jump than the 

 high jump of a man, whose body is carried more vertically, 

 than horizontally. For this reason, it is more essential for 

 a horse than for a man, to "get up" a certain degree of 

 speed in order to jump height well. 



The speed at which a horse goes at a jump (supposing 

 that it does not prevent him from "collecting" himself 

 properly), influences the width he can clear ; because (as we 

 have seen on p. 61) the force by which he is projected for- 

 ward into the air is equal to the force of propulsion derived 

 from his limbs, plus the impetus due to the speed at which 

 he is going. The greater this impetus, the lower will 

 be the "angle of elevation" at which the centre of gravity 

 of the body is propelled forward. 



We may, with approximate accuracy, define the " angle 

 of elevation" as the angle which a line passing through 

 the centre of gravity and a point midway between the 

 prints of the two hind feet, makes with the horizontal 

 plane, at the moment when the body leaves the ground. 



Looking at the si.ibject from a hasty point of view, those 

 of us who have not had practical experience, might come to 

 the conclusion that a horse would jump height as well when 

 going fast as when going slow, and that the only difference 

 is that, in the former case, the animal would be obliged to 

 take off further from the fence than in the latter. This sup- 

 position, however, does not hold good ; for the faster the pace, 

 the more weight is thrown on the forehand, and the greater 

 difficulty will the leading fore leg have in raising the fore- 

 hand off the ground. Hence, even without the valuable 



