Ikeleton of mofl quadrupeds prefents a quadrilateral 

 figure, having an inclined cylinder, fupported by 

 four pillars, or legs ; the projection of the head and 

 neck being counterpoifed by the additional weight 

 of the hinder parts. The flrength of a cylinder is 

 lefs, in proportion to its length, therefore a long- 

 backed horfe is weaker than a fliort one ; and hence 

 fmall animals can bear more weight, proportionally, 

 than larger :— a dog can carry his own weight, 

 which a horfe cannot do. The bones forming the 

 limbs are, wifely, not placed exadlly perpendicular 

 to each other, but in angles, by which means mo- 

 tion can be performed to a greater extent, and the 

 jarring and fhocks of fuch hard bodies prevented, as 

 well as their fradluring : but this deviation from the 

 perpendicular muft have powers to correct it, and 

 which is efteded by the mufcles. 



A mufcle is a red fibrous part, called tleili, poffefif- 

 ing a peculiar contradiie power, generally under the 

 influence of the will. To the end of a mufcle an 

 inelaftic cord is generally attached, called tendon, or 

 finas). The finews were by the antients called nerves ; 

 and hence a ftrono fmewed horfe was faid to be 

 nervous : a bold expreffion even was nervous ; and 

 the old books of farriery defcribc the back fmews ?0 

 the great nerves of the leg. 



Not only is the o;cneral inclination o£the machine 

 correded by the mufcles, but they alfo enable it to 



