1 86 RIGID OR ELASTIC CONNECTIONS CH. X 



movement of the horse, more or less sudden, in- 

 stead of being" resisted by the entire weight of the 

 carriage, is partially taken up by the spring and 

 then gradually communicated to the vehicle ; none 

 of the force is lost. 



The difference between an elastic and a long- 

 connection must be carefully noted. If the traces 

 are so long that the horse, when commencing to pull 

 gets into motion before acting upon the vehicle, he 

 is brought up with a jerk when the trace tightens, 

 and much of his power is wasted to no purpose. A 

 slack connection by an unyielding trace is therefore 

 objectionable. This does not apply to the case of 

 a horse pulling a canal-boat by a long rope, as the 

 sinking and rising of the rope takes the place of 

 elasticity, and the force expended in raising the rope 

 before the boat begins to move, is restored by its 

 sinking ao-ain. 



From a purely physiological point of view, a long 

 continued action by a horse, the same in character 

 and in amount, is undoubtedly more fatiguing than 

 when it is varied, and the majority of horsemen have 

 observed that in a given distance, on a road with 

 some undulations, a horse is less tired than on an 

 even grade, no matter if that grade is the minimum 

 one mathematically. 



The European roads, laid out by engineers with 

 the view of having- the easiest grades attainable, 

 nearly all have the grave defect of long steady 

 slopes for surmounting elevations with scarcely any 



