and Strength of Materials. 271 
Before the experiment this piece was bent 
about an inch, and the first trial gave it a set 
of nearly the same quantity on the opposite 
side, but the second left it bent upwards of 
two inches in its original direction ; which 
changes it afterwards followed. 
32. In the preceding experiments, I have 
endeavoured to obtain, to the best of my 
power, the exact extensions and compres- 
sions sustained by the sides of the pieces I 
used ; and it will appear by the lemma, (art. 
19,) that those extensions and compressions 
are as the distances of the neutral line from 
the sides to which they belong. The areas 
of tension and compression would then be in 
that proportion, since the pieces we made use 
of were all rectangular. 
If therefore we select from above the mean 
results, we shall have, in rectangular pieces, 
before the timber is much overstrained, the 
depth or area of tension to that of compres- 
sion— 
In Yellow Pine, 
From Ist experiment, as 2124 to 240 
2Qnd eeeeee errr eeere eeee 210 to 235 
Mean ratio 169 to 190 
