214: DRAUGHT AND HARNESS. 



a right-angle with the perpendicular, and this cannot 

 be prevented by any permanent arrangement of the axles r 

 trace-hooks, &c. Then, again, this law never contem- 

 plates the fact of the horse's shoulders becoming lower 

 that is, coming nearer to the ground from the 

 moment the animal stretches itself out and lays itself 

 into the collar ; and the amount of this lowering will of 

 course vary with the pace, being greatest at full gallop, 

 and also with the amount of effort required. 



The French artillery gives the trace an inclination of 

 only 11 with the horizon, and the rule seems to have 

 been deduced from a series of experiments made at 

 Metz by General Berge in 1816, at the time the new 

 system of artillery carriages, copied from the English r 

 was about being introduced.* This officer found that 

 the greatest effort was exercised by all horses strong, 

 weak, and medium when the trace was inclined between 

 10 and 12 with the horizon, or on an average 11, and 

 this greatest effort exceeded by more 'than ith that ob- 

 tained with the perfectly horizontal trace. Applying a 

 trigonometrical calculation to this fact, it will be found 

 that this angle of 11 corresponds with the supposition 

 of the horse's shoulders being pressed on to the ground 

 by a force equal to Jth the horizontal effort exerted. 

 Following out this indication, General Berge next tried 

 the effect of weighting the shoulders artificially in different 

 proportions, and found that by putting 100 kilogrammes 

 on the horse's shoulders he obtained the same effort 

 under an angle of between 6 and 7 that the unweighted 

 horses gave at 11; and that weighting with 50 to 60 

 kilogrammes under the latter angle gave an inferior 



* Migout et Bergery, ' Theorie des Affuts et des Voitures d'Ar- 

 tillerie.' 



