ON STATICS. 129 



would be formed by cutting the muscle across; and it i* not improbable that 

 the contractile force of the muscles of a healthy man is equivalent to about 

 500 pounds for each s(}uare inch of their section. The Avcakcst man can lift 

 with his hands about 1125 pounds, a strong man 400. Topham, a carpenter, 

 mentioned by Desaguliers, could lift 800 pounds. lie rolled up a strong 

 pewter dish with his fingers; he lifted with his teeth and knees a table six 

 feet long, with a half hundred weight at the end. He bent a poker, three 

 inches in circumference, to a right angle, by striking it upon his left fore 

 arm: another he bent and unbent about bis neck ; and snapped a liempen rope 

 two inches in circumference. A few years ago there was a person at Oxford 

 who could hold his arm extended for half a minute, with half a hundred weight 

 hanging on his little finger. A young gentleman, who has distinguished 

 liimself as a pedestrian by going gO miles in IQ hours, has also lifted two 

 hundred weights, one in each hand, and made them meet over his head. 



Sometimes feats of strength apparently extraordinary have been exhibited 

 by men who have not really been possessed of any material superiority. De- 

 saguliers relates, that one of them used to withstand the force of two horses 

 drawing at a girdle passed round his middle, while his feet acted on a firm 

 obstacle. By falling suddenly backwards, in an oblique position, he broke a 

 rope which was fixed a little before his feet. He supported one or two men 

 by forming his body into an arch ; and by a harness fitted to his hips, he sus- 

 tained a cannon, weighing two or three thousand pounds. In all these cases 

 the muscles principally employed are the extensors of the legs and thighs, but 

 tliQ^ passive strength of the bones is more concerned than the active force of 

 the muscles. In the instance, mentioned by Lahirc, of a young man who 

 raised an ass from the ground, by cords tied to the hair of his head, the sensi- 

 bility of the nerves of the skin must have been diminished by habit, so as to 

 allow the hair to be thus forcibly extended, without immoderate pain. 



The application of animal force is usually performed by means of a pro- 

 gressive motion. The muscles 'employed in this process are in general, if not 

 always, the strongest of the body, both by nature, and by habit; so that 

 when force alone is required, it is n)Ost ad\ antageously obtained from their 

 exertions. In walking, the centre of gravity is moved forwards Avith a ve- 

 locity nearly uniform. If the legs were perfectly inflexible, the centre of 



VOL. I. s 



