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SLANTING DIRECTION 0* THE SHOULDER. 



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

 and D is the power, or the situation at which the power is applied. If the 

 strength is applied in a direction perpendicular to the lever, as represented by 

 the line E, the power which must be exerted can easily be calculated. 



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 advantage gained. 

 The power here is twice as far from the centre as the weight is, and therefore 

 advantage is gained in the proportion of two to one ; or if the weight is equal 

 to 200 lbs., a force of 100 lbs. will balance it. If the direction in which the 

 power is applied is altered, and it is in that of the line F, will 100 lbs. effect the 

 purpose? No ; nothing like it. How, then, is the necessary power to be calcu- 

 lated? The calculation of the force which must be exerted in a direction inter- 

 mediate between the directions of the line E, and of the lever A B, involves 

 questions of geometry, somewhat foreign to the object of these pages. But 

 though the exact estimation of the power to be exerted at intermediate positions 

 is a question of some difficulty, a very little consideration will serve to shew that 

 the force to be applied, increases with, and in a greater degree than, the angle 

 between the directions of E and F. For suppose the direction of F to coincide 

 with that of A B, then no force exerted, however great, would support C, the 

 whole effect being to move the lever in the direction of its length. 



Let the shoulder of the horse be considered. 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 emanates, 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 per- 

 pendicular in the oblique than in the upright shoulder (see cut). In the upright 

 one, 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 thi3 

 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. They are exposed to less concussion, and especially con- 

 cussion in rapid action. The horse is also much safer ; for having less weight 

 situated before the pillars of support, he is not so likely to have the centre of 

 gravity thrown before and beyond them by an accidental 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 unfortunately happens that nature, as it were to supply the defici- 

 ency 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 ; 



