154 FARM ARITHMETIC. 



522. A horse weighing 1,600 pounds is worked with 

 another weighing 1,200 pounds. This team walks at a 

 rate of 2.5 miles an hour. What should be the pulling 

 power of the team, working 10 hours each day? 



523. The doubletree is adjusted so that each horse 

 shall pull one-half of the weight. This, of course, re- 

 quires the lighter horse to do more work and the heavier 

 less work than their weights warrant. Measured in 

 horsepower what is the excess for the lighter horse ? How 

 much less for the heavier horse than his just share? 



524. The doubletree is 4 2-3 feet long. At what point 

 should it be attached to the load so that each hors.e may 

 pull its just share when the difference in their weights 

 is considered? 



Process : 



1,600-pound horse = 160 pounds pull. 

 1,200-pound horse = 120 pounds pull. 



Total, 280 



160 -f- 280 = .57, part of load 1,600-pound horse pulls. 



120 -j- 280 .43, part of load 1,200-pound horse pulls. 



4 2/3 feet = 56 inches, length of doubletree. 



.57 X 56 = 32 inches 



.43 X 56 24 inches 



Total, 56 inches 

 Check, 160 X 24 = 120 X 32. 



The heavier horse should, of course, be hitched to the 

 shorter arm of the doubletree and the lighter horse to the 

 longer arm. When so hitched the amounts of work they 

 will do will be proportionate to their weights. 



525. On account of a difference in weight, the owner 

 of a two-horse team desires to give the lighter less work 

 than the heavier. He adjusts a 4- foot doubletree so that 

 one horse shall pull 60 per cent and the other 40 per cent 

 of the load. What is the length of each arm? Ans. 19 

 and 29 inches. 



