THE ANGLE OF TRACTION, ETC. 215 



result to that given by the greater weight (100 kilo- 

 grammes) under the lesser angle (6 to 7). 



But all these experiments having been made on a fixed 

 machine, and not on a movable carriage, were very 

 restricted in their application, which led the General to 

 make another set on the limber of an ammunition 

 waggon, both with and without the instrument previously 

 used.' : ' The results became, however, so contradictory 

 that he was obliged to give up the matter in despair ; 

 for not only was the relative power of some of the 

 horses, as previously shown on the fixed machine, com- 

 pletely reversed, but the indications of the instrument 

 did not correspond in any way with the different loads 

 placed on the limber, the only fixed result arrived at 

 being that the effort obtained by a sudden violent plunge 

 into the collar (coup de collier) was double that given by 

 the gradually-increasing pressure of a steady pull. 



Here are discrepancies and contradictions enough 

 both between the practical and scientific men, and also 

 in each group separately. There is, however, in the 

 quotation we have made from the ' Artillerist's Manual,' 

 one sentence that affords a clue to the really important 

 part of the question : we mean the words, " The best 

 disposition of the traces in draught is when they are per- 

 pendicular to the collar.'' For it is quite evident that a 

 horse will apply a greater amount of force to the trace 

 when the collar neither causes him pain nor interferes 

 with his muscular action, than in the contrary case, 

 when every effort becomes painful, and must be exerted 

 in a direction that does not accord with the general 

 mechanism of his frame ; therefore a greater useful 

 effect may be attained with traces that are so disposed 

 * A Dynamometer. 



