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FARM ARITHMETIC. 



breaking it, since the ultimate or breaking load is estimated as at 

 least ten times and frequently twenty times the safe working load. 



789. What is the safe working load that may be placed 

 at the middle point of a white pine scantling, 4" x 4" x 8', 

 when supported at the ends? 



790. On a white oak beam, 6" x 6" x 10'? Red oak? 



Sledding Time. 

 Logs are hauled out of a large forest to the saw mill. 



791. On a hemlock beam 2" x 10" x 16' ? 



Note. — The safe working load, when the load is uniformly 

 distributed throughout the length of the beam, is twice as great 

 as when concentrated at the middle point. 



792. In problem 786 what would be the safe working 

 load if uniformly distributed along the beam? 



Process: 390 X - = 780„ „Pounds. 



