Experiments and their Verification 



123 



ject of observation. The man in the sulky, important as his function 

 is, cannot quite form a correct idea of the action of the horse. 



As regards the idea that speed requires extreme forward ex- 

 tension and with it the long toe, toe weights, and what not, it is only 

 necessary to recall the illustrations of a previous chapter concerning 

 the pendulum-like swing of leg as a requisite of perfect balance. Per- 

 fect balance will not produce unsoundness such as curbs and swelled 

 tendons, but too great a forward extension is apt to do so. In Fig. 89 

 are given the points of shoulder (A) and buttock (B) of a moving 

 horse. The pendulum swing of fore and hind leg is indicated by A M, 

 A N, B M ; and B N', these being at equal distances from the vertical 

 or dotted line. The weight of the horse seems well supported and 

 the parallelogram representing the body and legs of horse moves in 



V /V P N O' M' P' N 1 



F/G. 69 



good symmetry. But let us force the forward extension of legs as in- 

 dicated by A O and B O', and we shall have a corresponding lesser ex- 

 tension backward, as in A P and B P'. It is apparent that the support 

 or stability of the parallelogram is weakened every time it is in the 

 position O A B O', or at extreme extension of A O and B O'. Add to 

 this the fact that the line A B, representing the body of the horse, is, 

 in consequence of such excessive forward extension, lowered more 

 than when such extension is normal, it is plainly seen how unnatural 

 and dangerous such a forced extension may become. 



This diagram will illustrate what is erroneously called "lengthen- 

 ing the stride/ 7 which in reality means increasing the forward ex- 

 tension. The danger of such a process becomes apparent when both 

 extremities act in the same manner, the belief being held that some- 

 how the hind legs ought to do what the front ones do. While they 



