OF IRON BEAMS. 5S^ 



that a beam of double length and depth of d 

 given one would ultimately be deflected the 

 same quantity as it. To see how this accords 

 with the experiments, we will take the short 

 beams, in experiments 28 and 31, and compare 

 their deflections with those from the beams of 

 double their length and depth in experiments 

 30 and 33; the ultimate deflections from the 

 small beams were .66 and .69 inch respectively, 

 and those from the large ones were .64 and .63 

 inch. Whence it appears, that the deflections 

 were nearly, but not precisely, equal ; there being 

 in both cases a deflection, somewhat greater 

 in the larger beam. 



PROBLEM. 



78. Suppose a beam supported at its ends, 

 by two props under A arid B ; and so formed that 

 it would just break with the same weight W on 

 the middle, or any other part, between tlie 

 supports. If then the prop be taken from 

 under B, and placed under any other point C, 

 what weight W laid on, half way between A 



and G, would be required to break the beam ?"^ 



no 

 A, IL !in. C B 



-^ TT 



If the beam had been uniform, the strength 

 would have been increased in the inverse ^atio 

 3 y2 



