THE EXPANSION OF SEA-WATEE BY HEAT. 
407 
Table I. 
Dilatometer B. Thermometer A. 
Temp. C. 
1 
Obs. yoI. 
Calc. yoI. 
Diff. 
0-00 
2828*56 
2828-54 
-0-02 
3-34 
2829-03 
2829*03 
0 00 
6-54 
2829-83 
2829-84 
+ 0-01 
9-58 
2830-89 
2830-91 
+ 0-02 
12-75 
2832-35 
28^2-30 
— 0 05 
15*94 
2833-95 
2833-98 
+ 0-03 
19-15 
2835-91 
2835-93 
+ 002 
22-32 
2838-00 
2838-09 
+ 0-09 
25-45 
2840-55 
2840-44 
-0-11 
28-88 
2843-27 
2843-24 
- 0-03 
32-08 
2846-01 
2846-05 
+ 004 
35-02 
2848-78 
2848-77 
-001 
These results may be represented with sufficient accuracy by a formula of the form 
V=K+L£+M£ 2 +Nf. 
The values of the constants K, L, M, and N were found by substituting successively 
for V and t the 12 corresponding values given in the Table as deduced from the experi- 
ments, and the expressions so obtained were then added together in consecutive groups 
of three, so as to form 4 equations of condition by the solution of which the 4 unknown 
quantities were determined. 
The values of K, L, M, and N were thus found to be — • 
K= 2828-540, 
L= 0-091311, 
M= 0-0171712, 
N=— 0-00009373. 
The third column in the foregoing Table gives the volumes, calculated by the aid of 
these values, which correspond to the observed temperatures contained in the first column ; 
and the fourth column shows the differences between the observed and calculated results. 
Dividing each coefficient by K, and correcting for the expansion of the glass 
(0-0000254 for 1°C.), we obtain the following formula, as representing the expansion 
between 0° and 36° of sea-water of sp. gr. 1-02867 at 0°, the volume at 0° being 1. 
V=l-|- -000057682 ^-p-0000060715 f 
— -000000032983 t\ 
The variations in the specific gravity of oceanic waters are, comparatively speaking, 
very small; according to the observations of Mr. J. Y. Buchanan, the Chemist to the 
‘ Challenger’ Expedition, they lie between the extremes 1-0278 and 1-0240. Still the 
question suggests itself — Is the law of the thermal expansion, as deduced from the fore- 
going observations, strictly applicable to all oceanic waters \ The importance of an answer 
to this question will be evident when we bear in mind that, in order to be of value in the 
3 L 2 
