SLANTING DIRECTION OF THE SHOULDER. 



231 



A is a lever, resting or turning on a pivot B ; C is the weight to be 

 raised, and D is the power and the situation at which the power is applied. 

 If we apply our strength in a direction perpendicular to tlie lever, as repre- 

 sented by the line E, we can easily calculate the strength which we must 



exert. In proportion as the distance of the power from the pivot or centre 

 of motion exceeds that of the weight from the same place, so will be the 

 advantao-e o-ained. The power here is twice as far from the centre as the 

 weight is, and therefore we gain advantage in the proportion of two to one ; 

 or if the weight be equal to 200 lbs., a force of 100 lbs. will balance it. If 

 we alter the direction in which the power is applied, and suppose it to be 

 in that of the line F, will 100 lbs. now do? No; nothing like it. How 

 shall we calculate, then, the power that is necessary? We must prolong 

 the line of direction until another line, falling perpendicularly from the 

 lever, and commencing at the centre of motion, will cut it; and the length 

 of that line will give us the actual effect of the strength we employ. Now, 

 this new line is but half as long as the distance of the weight from the 

 centre of motion, and therefore we lose advantage in the proportion of two 

 to one ; or a strength equal to 400 lbs. must be exerted to raise the 200 

 lbs., and so on in proportion to the deviation from the right or perpen- 

 dicular line. 



Let us next take the shoulder of the horse. The point of the shoulder, 

 the shoulder joint, is the pivot or centre of motion ; the leg attached to the 

 bone of the arm is the weight ; the shoulder-blade being more fixed is the 

 part whence the power is exerted ; and the muscles extending from the one 

 to the other are the lines in which that power is exerted. These lines 

 approach much more nearly to a perpendicular in the oblique than in the 

 upright shoulder (see cut). In the upright shoulder, the shoulder-blade 

 and the bone of the arm are almost in a straight line, and the real action 

 and power of the muscle are most strangely diminished. In this point of 

 view the oblique shoulder is most important. It not only gives extensive 

 action, but facility of action; the power of the muscles is more than doubled 

 by being exerted in a line approaching so much nearer to a perpendicular. 



There is yet another advantage of the oblique shoulder. The point of 

 the shoulder is projected forward ; and therefore the pillars which support 

 the fore part of the horse are likewise placed proportionably forward, and 

 they have less weight to carry ; and are exposed to less concussion, and 

 especially concussion in rapid action. The horse is also much safer; for 

 having less weight lying before the pillars of support, he is not so likely 

 to have the centre of gravity thrown before and beyond them by an acci- 

 dental trip ; or, in other words, he is not so likely to fall ; and he rides more 

 pleasantly, for there is far less weight bearing on the hand of the rider, 

 and annoying and tiring him. It likewise happens unfortunately that 

 nature, as it were to supply the deficiency of action and of power in an 

 upright shoulder, has accumulated on it more muscle, and therefore the 

 upright shoulder is proverbially thick and cloddy ; and the muscles ot the 



