428 
MR. HODGKINSON’S EXPERIMENTAL RESEARCHES 
Lamande’s Experiments upon Square Pillars of Oak. 
Length of 
pillar. 
Side of 
square. 
Value of b deduced 
(Art. 64.) from 1st 
experiments below. 
Value of c computed 
from Rondelet’s 
experiments. 
Breaking weight. 
Calculated breaking 
weight from formula 
b c 
y b+i 0 
feet. 
6-375 
inches. 
2-126 
lhs. 
lbs. 
28638 
lhs. Mean. 
'7244') 
IZ k 69 
_7878j 
lbs. 
4-25 
2-126 
17480 
28638 
'11844') 
12225 
13565 f 12523 
^ 12458 J 
12850 
2-125 
2-126 
699205 
28638 
'15631' 
21296 
19993 
21060_, 
>19495 
21908 
6-375 
3-18 
38888 
64072 
< 
'26939'' 
28987 
23929 
33048 
^36902^ 
!> 29961 
28659 
4-25 
3-18 
87498 
64072 
\ 
f 436391 
36865 
36205 
^28182, 
>36223 
41358 1 
2-125 
3-18 
349993 
64072 
f 50958 ] 
L 50958 
> 50958 
56207 
6-375 
4-25 
124069 
114444 
< 
'64090) 
54062 ^ 60783 
^65608 J 
67646 
4-25 
4-25 
279156 
114444 
< 
[100755) 
S [ 89090 
L 96368 J 
87532 
2-125 
4-25 
1116620 
114444 
f 95262') 
\ 1 94476 f 96001 
1_ 88442 J 
106275 
The breaking- weights above were calculated on a supposition that the oak resisted 
with a force of 6336 lbs. per square inch. But Mr. Barlow* states that oak, accord- 
ing to Rondelet (in an early edition of his work), required from 5000 to 6000 lbs. 
per square inch of base to crush it. If I had adopted these measures of the strength, 
instead of the former, the calculated values would have been a little lower, and the 
* Treatise on the Strength of Timber, &c. 
