40 SEATS AND SADDLES. 



presented by d P in the figure ; and the further effect 

 of this is, that the centre of gravity of the whole 

 machine resting on the basis b b, is thrown farther 

 back on the line d a. A horse's neck is not, however, 

 an inflexible straight line like an ordinary lever. 

 Moreover, the head, which forms no inconsiderable 

 portion of the overhanging weight, can be bent at 

 various angles to the neck. We have it therefore in 

 our power not only to diminish the external prepon- 

 derance of these members by altering their relative 

 position as described above, but also actually to dimin- 

 ish the distance at which the perpendicular falls out- 

 side the basis first, by bending the neck, by which 

 the length of the lever is curtailed ; and still further, 

 by making the head assume more and more acute 

 that is, smaller angles with the line of the neck, 

 whether this latter be straight or curved. 



This is shown by fig. 4, where the natural that is, 

 unimproved position of the head and neck makes the 

 perpendicular fall at the distance D 2V outside the 

 basis of the animal ; and this corresponds nearly to a 

 line of gravity, x y, falling through one of the dorsal 

 vertebrae nearer to the neck than the fourteenth, to 

 which reference has been made. And by elevating the 

 neck somewhat, curving it at the same time, and making 

 the head assume an acuter angle with it, we bring back 

 the centre of gravity perhaps to E F, the perpendicular 

 falling through the fourteenth vertebra, or centre of mo- 

 tion and this is the safest and most generally appli- 

 cable position : for cavalry purposes it is absolutely 

 indispensable. Finally, if we bring the neck still higher 

 up, curving it still more, as shown in the figure, we 

 can bring the centre of gravity back to the line G ff, 



