130 HORSE AND MAN. 



Another inventor realised the latter defect, and 

 so the celebrated screw-shoe was devised. 



This was a most complicated and expensive piece 

 of mechanism, consisting of four distinct parts. First 

 came the toe-piece. This was something like the 

 capital letter T, with a curved cross-piece. The stem 

 passed completely under the middle of the hoof, arid 

 had at the end a nut which worked the screw after 

 which the shoe was named. 



To the arms of the toe-piece the side-pieces were 

 connected by rivets similar to those of the jointed 

 shoe, their other ends or ' heels ' coming against the 

 screw. So, by turning the nut, the sides could be 

 pushed further apart, or brought nearer together, so 

 as to suit either a round or a long hoof. 



This would have been a delightful arrangement 

 if, like its predecessor, the screw-shoe could have 

 remained on paper. When reduced to practice, how- 

 ever, its failure was even more disastrous. 



In the first place, there were two rivets instead 

 of one, so that it was doubly weak. In the next, 

 the screws, which were really superfluous appendages, 

 caused the stem of the toe-piece to work up and 

 down at each step, until they fell out and were lost. 

 But the third defect was an absolutely ludicrous one. 

 The reader will remember that the expansion and 

 contraction of the hoof is produced by the pressure 



