88 ANIMAL MECHANICS 



to hang by the feet and knees, to struggle 

 against each other, by placing the soles of their 

 feet in opposition, and to pull with their hands. 

 No doubt, if such exercises be persevered in, the 

 muscular powers will be strongly developed. But 

 the first question to be considered is the safety of 

 this practice. We have seen a professor of gym- 

 nastics, by such training, acquire great strength 

 and prominence of muscles ; but by this unnat- 

 ural increase of muscular power, through the 

 exercises he recommended, he became ruptured 

 on both sides. The same accident has happened 

 to boys too suddenly put on these efforts. 



It is proper to observe, that when the muscular 

 power is thus, we may say, preternaturally in- 

 creased, whether in the instance of a race-horse, 

 an opera dancer, or a pupil of the Calisthenic 

 school, it is not merely necessary to put them on 

 their exercises gradually in each successive lesson, 

 but each day's exertion must be preceded by a 

 wearisome preparation. In the great schools, like 

 that at Stockholm, the master makes the boys 

 walk in a circle ; then run, at first gently ; and 

 so he gradually brings them into heat, and the 

 textures of their frame are composed to that state 

 of elasticity and equal resistance, as well as to 

 vital energy, which is necessary for the safe dis- 

 play of the greater feats of strength and activity. 

 This caution in the public exercises is the very 



