108 THE MECHANICAL FUNCTIONS. 



the mechanism of the animal frame; one set of powerful 

 muscles being employed for the larger movements, and ano- 

 ther set provided for the accurate regulation of the more 

 delicate inflections and nicer positions. This we shall find 

 exemplified in the movements of the fingers, and of many 

 of the organs of the finer senses. 



In general, however, we may observe that, the mechanical 

 expedients devised by Nature for efiecting each particular 

 purpose are characterized by the most admirable simplicity. 

 In this respect, also, as well as in all others, we cannot fail 

 to recognise their infinite superiority over every correspond- 

 ing invention of man. 



"In human works, thoug-h labour'don with pain, 

 A thousand movements scarce one purpose gain: 

 In God's, one single can its ends produce. 

 Yet serves to second, too, some other use." Pope. 



We may generally observe, in the mechanism of the 

 joints, that the muscles are made to act, either directly or 

 by means of their tendons, at a point much nearer to the 

 axis of motion than the resistance to be overcome. With 

 regard to the direct force, therefore, it is evident that they 

 must act with a great mechanical disadvantage; and this dis- 

 advantage is still farther increased by the obliquity of the 

 action with reference to the direction of the motion. But 

 the contractile power, which is inherent in the muscular 

 fibre, is so enormous, as amply to afi'ord these losses, great 

 as they necessarily are; while, on the other hand, full com- 

 pensation is made by the greater freedom and velocity of 

 motion thereby obtained. Strength is sacrificed without 

 scruple to beauty of form or convenience of purpose; and 

 that disposition of the force is always adopted, from which, 

 on the whole, the greatest practical benefit results. Every 

 where do we find the wisest adaptation of muscular power 

 to the objects proposed, whether it be exerted in laborious 

 efforts of the limbs and trunk; whether employed in ba- 

 lancing the frame, or urging it into quick progression; or 

 whether it be applied to direct the delicate evolutions of 



