50 Scats and Saddles. 



amount by which the pohit A^Hes outside of the basis 

 b b; and if the head and neck be hfted to the position 

 d O, it will be represented by the shorter distance d JV' ; 

 and if still more elevated to d P^ then by the still shorter 

 one d JV . Consequently, the relative overhanging 

 weight of those portions of the horse's body may be 

 diminished in proportion as their position is brought 

 nearer to that represented by ^ 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 \s thrown far- 

 ther back on the line da. A horse's neck is not, how- 

 ever, an inflexible straight line like an ordinary lever. 

 IVIoreover, the head, which forms no inconsiderable por- 

 tion 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 preponderance of 

 these members by altering their relative position as 

 described above, but also actually to diminish the dis- 

 tance at which the perpendicular falls outside 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 Z^iV outside the basis 

 of the animal ; and this corresponds nearly to a line of 

 gravity, x y^ falling tlirough one of the dorsal vertebrae 

 nearer to the neck than the fourteenth, to which refer- 

 ence has been made. And by elevating the neck some- 

 what, curving it at the same time, and making the head 

 assume an acuter angle with it, we bring back the cen- 

 tre of gravity perhaps to ^ -^, the perpendicular falling 

 through the fourteenth vertebra, or centre of motion — 

 and this is the safest and most generally applicable 



