IX.] STRENGTH OF OAK. 103 



men, proved to be the weakest, the respective breaking 

 weights showing a difference of nearly 42 per cent. 



Turning to the specimens marked i' to 6', taken 

 from the other side of the tree, we find a similar result as 

 regards the inner and the outer layers, the greatest 

 strength being again near to the centre of the tree; 

 No. S', however, bearing the next greatest strain. The 

 pieces Nos. 2', 3', 4', and 6', each broke as the weight 

 of the scale was applied, and are therefore of little value. 



We may gather, however, from the trial, that from 

 the centre to the circumference of this tree there was 

 clearly a diminution of strength, which, although not 

 quite proportionate to the decrease observed in the 

 specific gravity of the several pieces, is yet in some 

 degree approximate to it. 



I infer from this that the tree had not reached 

 maturity when it was cut down, and that it was still in 

 the prime of life. Had it been otherwise, we should 

 have expected, when viewed by the light of other ex- 

 periments, to find that the point of density and greatest 

 strength would lie in the piece marked 4, or even farther 

 removed from the centre. 



There can be very little doubt that the wood of 

 this tree, if used in its greatest bulk, or in any large 

 scantlings, would have been found to possess fully the 

 average strength of Oak timber, and that it was only 

 weak in certain parts, as discovered on trial when cut 

 into strips of 2 inches square. There still remains, 

 however, the fact that in a fine tree, sound and 

 apparently free from defect, nearly the whole of one 

 side was found to be faulty, while the other half proved 

 to be inferior in strength to the specimens of average 

 quality noticed in the Tables VII. and VIII., the mean 

 breaking weight of the best side being 562 lbs., as com- 



