The Fi-aDicwork of the Horse. 53 



ledge of this beautiful mechanism that judges of horses 

 attach so much importance to the length of these two 

 levers, and to their lying at right angles to the hip-bone 

 and shoulder-blade respectively, which is recognized 

 by the form of the haunch, and what we call a good 

 shoulder ; the length of the stride and its power depend- 

 ing, as is very evident, on those particulars to a great 

 extent. 



A farther proof of the same fact may be gathered 

 from Plate II., which shows the principal muscles, and 

 the way in which they are arranged. It is those in the 

 back, loins, hips and shoulders that concern us here 

 more especially ; and we perceive that the principal 

 ones of these all coalesce, as it were, into the large flat 

 tendon covering the identical portion of the back pointed 

 out as the centre of motion. This tendon, like all others, 

 is devoid of contractile power ; and tlie corresponding 

 sets of muscles of the fore and back hand exert their 

 contractile powers upon it in opposite directions, while 

 it remains stationary, so to say — the whole process 

 having a certain analogy with the ftimiliar instance of 

 a pair of curtains drawn forward by cords to the middle 

 of a window. 



According to the laws of mechanics, when two forces 

 of equal intensity cross each other, as the lines P ^, 

 R S Ao in fig. 4, the line in which the combined result 

 of both is farther propagated will lie equally distant 

 from and between the two original forces ; and this is, 

 in the instance before us, perpendicularly upward, as 

 shown by the upper arrow ; and the antagonistic force 

 of gravitation — in plain language, the weight of the 

 rider — will be best met when it acts in precisely the 

 opposite direction, or perpendicularly downward in 

 the direction of the lower arrow ; and therefore, if the 

 weight of the rider lie, from his mode of sitting, across 

 this perpendicular — for instance, toward the shoulders 

 5* 



