368 
PROFESSOR A. M. WORTHINGTON ON THE 
Subtracting this amount from the ordinate of the diagram corresponding to 10 
atmospheres, the remainder, of length 16*17 divisions, gives the corrected value of the 
absolute strain, and is equivalent to 10‘67 ten-thousandths of the whole volume, per 
stress of 10 atmospheres, or to ‘0001067 per atmosphere, a result which is about 
15 per cent, higher than that of Mr. Skinner. From the nature of my observations 
on this point, I do not think that much importance is to be attached to this discrep¬ 
ancy, which represents a possible error of 2 millims. to be divided between the 
measure of the length of the bubble on the release from 10 atmospheres tension, and 
the measure of the recession of the mercury in the experiments just quoted. 
wliere A is the observed apparent alteration of volume in millims. of tube, due to 10 atmospheres tension, 
when the vessel was full. 
Hence 
r — A _ v u 
n n 
Substituting this value for v a in (i.), and multiplying up 
(n — 1) v g + nv m = na — A, 
n — 1 
a — 
A 
n — 1 
1 ’ 
in which expression — Vm i s a small corrective term due to the compressibility of the mercury, while 
^ is a small corrective term due to the compressibility of the residual alcohol present with 
the mercury in the bulb. 
The numerical values required were obtained as follows :— 
grms. 
The weight of mercury and alcohol together was found to be . . . 769 - 3 
„ ,, alone. 768’38 
Therefore, weight of residual alcohol alone = 
0-92 
Hence the volume of the the mercury alone = 56'5 cub. centims., and the volume of the residual 
alcohol alone = T15 cub. centims. 
The volume of the alcohol used in the stretching experiments was 58'5 cub. centims., therefore 
58-5 
n = j-j^ = 50 - 6, and n — 1 = 49 - 6. 
The observed recession of the mercury (a) = 7'22 millims. of tube, as already stated in the text. 
A = 22'7 millims. of tube, as read off from the line in the diagram. 
v m = '273 millims. of tube (deduced from the value of the compressibility of mercury given in 
Lupton’s tables, viz., - per 10 6 grms. per sq. centim., and the fact that yoWo the 
Hence 
K /?. K 
volume of mercury employed = —of 1’513 millim. of the tube). 
OO'b 
v _ 50-6 7 . 99 506 7 22-7 
*' _ X ' “ S? X 273 ~ 
- 7-36 — 0-278 — 0-456. 
= 6‘626 millims. of tube. 
