496 



THE STRENGTH 



bore ; and the difference of strength would 

 have been much greater, if we had used two 

 equal whole beams. Hence we see the impro- 

 priety of turning beams the wrong side up, as 

 is often done in Factories. But this matter was 

 still more clearly shewn in one of our early 

 experiments (art. 23), where a t section of 

 cast iron bore nearly 4 times . as much one way 



up as the other. '\ -Mfr»r!r;T?Tr< ?; ^^"UOil 



XXIV. EXPERIMENT. 

 Dist. between supports 7 ft. depth of beam 5.2 ins. 



Dimensions of section in inches. 



Area of top rib = 2.25 x .35 = 79^ I 

 „ bottom rib = 6.00 x -77 = 4.62 ' C 



Thickness of i 



Weight of casting = 1 cwt. qrs. 16 lbs =128 lbs. 



fit d<j^<.W 



Weights 

 in lbs. 



7257 - 



7947 - 



8637 - 



9327 - 



10017 - 



10707 - 



Deflections in Retnrned to, 



parts of an inch. (weights removed.) 



-------- perceptible set. 



- - .35 .08 



_ . .43 .08 



- . .51 - -t^i^Jui 



- . .53 .13 



_ . .50 - -'- -^^14 -'^^^'^ ^^^'' 



