14 THE HORSE IN MOTION. 



play of his forces and their balance as a steam hammer, which may be 

 adjusted to a force sufficient to forge a shaft for an ocean steamer or 

 to crack a nut. 



It cannot be expected that many of those persons who are inter- 

 ested in the movements of the horse will be familiar with the anatomi- 

 cal terms necessary to be used in the description of the simplest 

 motion, and it cannot be made intelligible without them ; much less 

 can it be expected that one will be able to comprehend a full stride 

 from any analysis that can be given without such knowledge. 



The writer thinks himself warranted in the assertion that the correct 

 interpretation of the mechanical action of the horse cannot be obtained 

 from any existing work. It is very desirable that it should be under- 

 stood by every one who is interested in his achievements, and by artists 

 as well. To facilitate this study, technical terms will be emitted as far 

 as possible, and where they are employed they will be accompanied by 

 popular ones as far as they are known. 



One of the sources of difficulty to the non-professional student is 

 the distinctive names given to different tissues whose mechanical 

 function is the same. Whether a muscle has its termination in facia 

 aponeurosis or at the bone on which it acts, either directly or in- 

 directly, may be important to the anatomist or surgeon ; but to those 

 who desire to understand the mechanical action it is a matter of indif- 

 ference, very perplexing, and a fatal bar to the comprehension of the 

 subject ; to such it is of little consequence whether the action is direct 

 by muscular attachments to bones, or indirect through facia or other 

 fibrous tissue. In all cases I shall use such terms as will most cor- 

 rectly give my meaning in the interpretation of their action. 



Another source of confusion in the study of the muscles of mo- 

 tion in quadrupeds is the conflicting names given to them. When, 

 on the restoration of the cultivation of science, comparative anatomy 

 began to attract the attention of naturalists, human anatomy had 

 already received much attention, and names had been bestowed upon 

 all the principal organs. Some of them were purely fanciful ; others 

 were based on their resemblance to other objects. The muscles were 

 often named from their supposed function, or their correspondence to 



