116 VETEEINAEY HYGIENE 



mechanical a standpoint. There is something more than 

 the machine to be considered, there is the animal. 



In spite of what has been said above, it is possible to 

 form an idea of the amount of daily work which a horse 

 may reasonably be called upon to perform, and this amount 

 may be stated at 3,000 foot tons per diem, viz., ten times 

 more than a man. 



In some of the exact experiments made in Germany by 

 Wolff, Lehmann, and others, it has been found possible to 

 calculate with exactitude the amount of actual work per- 

 formed by a horse. In one set of experiments lasting over 

 eight weeks they made the animal produce from 2,600 foot 

 tons per diem, to 7,800 foot tons, but loss of condition was 

 very evident with the latter amount. In another series 

 from 1,500 to 4,500 foot tons of work were performed daily; 

 loss of condition and weight followed the latter, though the 

 diet was liberal. In a third series lasting several weeks 

 from 2,500 to 4,800 foot tons were performed daily. 



We shall not, therefore, be far wrong in adopting 3,000 

 foot tons as the normal moderate work of a horse performed 

 under natural conditions, and the value of this work may 

 be seen in the following table, where it is assumed that the 

 weight of the horse's body and that of its rider amount to 

 1,000 lbs. 



Foot Tons. 

 9 hours' work at 3 miles per hour exercises a force equal to 3,000 

 5* „ 4 „ „ „ 3,000 



3,000 

 3,000 

 3,000 

 3,000 



Later on the question of the amount of work to be 

 expected from horses will be considered, but it is permis- 

 sible here, in the interests of dieting, to draw attention to 

 the extraordinary influence of velocity as shown in the 

 above table. The resistance the animal body meets with 

 during work increases as the square of the velocity, but the 

 force necessary to overcome this resistance increases as the 

 cube. 



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