TIMBER AND TIMBER TREES. 



[chap. 



Table Vllt.— English Oak. 

 Transverse Experiments. — ^nd Example. 



Remarks. — No. 7 broke short ; 8 and 12 with 7 to 13 inches length of fracture ; 9, 

 10, and II with 15 inches scarph-like splintery fracture. 



The Tables VII. and VIII. each refer to parcels of six 

 pieces, which were taken from trees of good average 

 quality and size, moderately seasoned, and fit to be 

 applied to architectural works, the specific gravity vary- 

 ing from 670 to 1005. Of the twelve pieces tested, the 

 elasticity of two, after the weight of 390 lbs. was re- 

 moved, was perfect. One piece recovered its straight- 

 ness to within -3 12 inch, while of the remainder, nine in 

 number, the elasticity was in all something better, 

 though not quite perfect. 



The deflections varied under this weight of 390 lbs. 

 from 1-500 to 3-625 inches, the ultimate deflections at 

 the crisis of breaking varying from 4-125 to i roo inches ; 

 while the breaking weight varied from 590 to 1,005 lbs., 

 the average results being 201-58 lbs. on the square inch. 



Taking the mean of the figures in the Tables VII. and 

 VIII., we have a deflection of 2-489 inches with 390 lbs. ; 

 but only -151 inch after the weight had been removed. 



