THE ANIMAL AS A MOTOR. 



59 



An Austrian army officer rode, in June, 1893, from 

 Vienna to Berlin, 388 miles, in 71.33 hours, or 5.45 

 miles an hour, resting an hour in twelve, but losing his 

 horse after the race was concluded. The cyclists " 

 have beaten this record. 



Rennie found the hauling power of a draught-horse 

 weighing 1200 pounds was equal to about 108 pounds 

 at 2.5 miles an hour, or 22,300 foot-pounds per minute, 

 for eight hours per day, a 20-mile haul. This is a little 

 over two thirds of a Watt " horse-power," at which 

 value Rennie rates the average draught-horse, and this 

 is taken to be, ordinarily, five times the power of a 

 man. Between 2\ and 4 miles an hour, the hauling 

 power of the horse is nearly inversely as the speed. 



The mule carries a load of 200 to 400 pounds, and 

 its day's work consists, usually, in the transportation 

 of the equivalent of 5000 to 6000 pounds one mile. 

 The ass carries 175 pounds and upward, and the day's 

 work is the equivalent of 3000 to 4000 pounds one 

 mile. 



According to Weisbach, a horse should be able to 

 carry 240 pounds on its back 3.5 feet per second ten 

 hours a day. Carrying 160 pounds he should be able 

 to trot 7 feet per second seven hours a day, doing, in 

 the day, ten per cent less work than before, nearly. 



The pulling power is said to be, as a rule, about one 

 fifth the weight of the animal. Its usual effort, in the 

 case of the horse at least, is seldom in excess of one 

 tenth, or about one half the maximum. One hundred 

 pounds is a common pull for the average horse in 

 draught vehicles. 



19. Effective Methods of Application of man-power 

 are sought by the engineer. The best is considered to 



