ELEMENTS OF HIPPOLOGY. 99 



The shoulder-blade, as has been said, has no bony union 

 with the spinal column. It is simply bound on the ribs and 

 spinal column by a number of very strong muscles that control 

 its movements. The center of its motion is about one-third its 

 length from the upper end. When the foot is brought forward, 

 the lower end of the shoulder-blade swings forward and upward, 

 around this center of motion,' and the upper end swings back- 

 ward and downward. 



The saddle must be so placed as not to interfere with the 

 free play of this bone. It has been found that if the front of the 

 side-bar of the McClellan saddle is placed so that three fingers 

 can be laid between it and the shoulder-blade when the horse is 

 standing, the play of the bone will not be interfered with. 



The saddle in ordinary use for pleasure-riding does not need 

 to be built to carry any load but the rider. It has a very small, 

 rigid frame, called the tree, is carefully and thoroughly pad- 

 ded, and needs no blanket or pad under it to protect the horse's 

 back. A leather sweat-pad, called the numnah, should be used 

 under it to protect its padding from becoming ruined by sweat, 



These saddles should be padded to fit each particular horse, 

 and should not be used on another horse. If this precaution is 

 taken, the saddle will naturally fall on its proper place and will 

 stay there. As long as the padding is good and the numnah 

 kept clean, there is small danger of injury being done to the 

 horse's back. 



The McClellan saddle, however, must often be changed from 

 one horse to another. Its tree is larger and its bearing surface 

 considerable to provide points of attachment for the packs that, 

 from time to time, must be fastened to the pommel and cantle. 

 The horse's back is protected by a folded woolen blanket. 



This blanket must be folded very carefully; no wrinkles 

 should be allowed, nor any dirt or other foreign substances, in any 

 of its folds. Anything that causes undue pressure on any spot 

 under the saddle will compress the capillaries of that spot and 



