62 



divide his body weight by 5.757, and if intended for only moderate 

 work to add to the product 28 pounds. It has to be noted that the 

 observations were made upon military horses. It is doubtful if it 

 would work out so accurately if applied to all horses used for the 

 saddle. 



According to Lavalard'* the general opinion of cavalry oflicers who 

 have studied the question is that measuring the distance covered and 

 the rate of speed is practically the only method for determining the 

 work done by a saddle horse. He states that Marcy computes that 

 the work accomplished in a given time is proportional to the square of 

 the velocity, his coefficients being eS.42 for walking or pacing, 16 for 

 trotting, 28.62 for cantering, and 68.39 for a full gallop. In other 

 words, 4.5 times as much work is performed when trotting as when 

 walking, 1.75 times as much when galloping as trotting, and 2.5 times 

 as much at a full gallop as on an ordinary trot or canter. These val- 

 ues are calculations rather than results obtained by experiments. 



According to Poncelet* a horse carrying a weight of 120 kilograms 

 (265 pounds) and traveling at a speed of 1.1 meters (3.6 feet) per second 

 for 10 hours per day performs 4,752,000 kilogrammeters (34,214,400 

 foot-pounds) of work. If the weight carried equals 80 kilograms (363 

 pounds) and the speed is 2.2 meters (7.3 feet) per second, 4,435,000 

 kilogrammeters (31,932,000 foot-pounds) of work will be performed 

 in 7 hours. 



The Prussian cavalry horses, according to Ellen bcrger's^ estimation, 

 perform 1,500,000 kilogrammeters (10,800,000 foot-pounds) of useful 

 work daily during the winter months. In the spring and summer 

 months extra military duties increase this amount by 200,000 kilo- 

 grammeters (1,440,000 foot-pounds) daily. Different values have been 

 proposed I)}' other investigators for saddle horses of various kinds. 



The speed at which the horse travels, the way in Avhich the load is 

 distributed, the external temperature, and other conditions evidently 

 have an effect upon the work performed. 



According to Colin's* figures a horse walking 1 kilometer (0.63 

 mile) in 10 minutes travels at a speed of 1.66 meters (5.4 feet) per 

 second. Trotting the same distance in 4.25 minutes the distance cov- 

 ered is 3.92 meters (12.9 feet) per second. The average speed of a 

 trotting horse was calculated to be 2.72 meters (8.9 feet) per second. 

 These values refer especially to arm}^ horses. 



MUSCTJIiAR WORK IN ITS RELATION TO THE RATION. 



Many experiments have been made, chiefly in Europe, to determine 

 the exact relation between the amount of muscular work performed 

 and the amount of the different nutrients required per day. It is the 

 opinion of Wolff and Muntz, and others who have been especially 



« Experiment Station Record, 12 (1900-1901), p. 4. 

 ^ Quoted by Lavalard," loc. cit. 



