34 



HORSE AND MAN. 



is not hard like the wall, which, if properly treated, 

 becomes so hard that a knife will scarcely touch it, 

 but is quite soft and elastic, feeling when handled 

 much like vulcanised indiarubber. 



As the horse steps, the weight first comes on the 

 hinder, or heel portion of the frog, then upon its 

 centre, and afterwards upon the wall. 



Two objects are fulfilled by this structure. Firstly, 

 by means of this elastic material interposed between 

 the horse and the ground, the 

 animal treads softly, and does not 

 'jar' the body, as would be the 

 case if the bearing came first on 

 the wall. Horses are instinctively 

 aware of this fact, and when at 

 liberty in a field they may be 

 seen shuffling about in order to 

 obtain the central bearing, for 

 which the hoof was made. 



Acfain, man has imitated nature in artificial loco- 

 motion. 



In many forms of carriages, especially those of 

 railways, the weight' rests upon the central portion 

 of the springs, as seen in the accompanying illustra- 

 tion. The inventors of this form of spring, and of 

 the diagonal attachment which is figured on page 

 33, were probably unaware that their inventions 



UNSHOD HOOF OF WILD 

 HORSE. 



