THE EFFICIENCY OF THE HORSE 



THE classic experiments of James Watt placed the 

 working power of a 1500-pound cart horse at the 

 ability to lift 33,000 pounds to a height of one foot 

 each minute, whence came the term "horsepower." 

 More recent experiments, however, indicate that the energy 

 delivered by the average horse is nearer 22,000 foot-pounds per 

 minute, or two thirds horsepower. General Morin, a French 

 investigator, puts the horse's capacity at .79 h.p. Trautwine 

 puts the net useful work of the average horse working in a 

 circular sweep at 10,000,000 foot-pounds per day of eight hours. 

 Assuming 85 per cent, mechanical efficiency for the sweep, this 

 would be equivalent to practically J h.p. Langworthy, in 

 Bulletin 125, Office of Experiment Stations, puts the total 

 daily work of the average horse at 10,560,000 foot-pounds. 

 Conclusions of expe imenters vary considerably, doubtless 

 because they have worked under different conditions with 

 horses of different size and individual merit. 



Numerous authorities unite in putting the working draft 

 or pulling power of a horse at one tenth his weight when work- 

 ing at the rate of two and one half miles per hour continuously 

 for ten hours per day. Under these circumstances a 1200- 

 pound horse will develop .8 h.p., and a 1500-pound horse 

 1 h.p. Trautwine and King both state that if the hours of 

 work be shortened toward a limit of five hours per day, the 

 draft of the horse may be increased accordingly. They state 

 also that between the speeds of three fourths of a mile and 

 four miles per hour the working draft of the horse will be 



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