10 
THE VOYAGE OF H.M.S CHALLENGER. 
Having obtained the density of the water at the temperature which it had during the 
observation, we have to reduce it to its value at some standard temperature. It is only 
aft. r this reduction that we can compare the densities of waters observed at different 
times and places in their bearing on the saltness of the water. 
During the cruise the only available tables of the expansion of sea-water for tempera- 
ture were those of Prof. Hubbard (Tables VI., VII.). 
In Hubbard’s Table 1 the volumes of a mass of sea- water at different temperatures are 
given referred to that at 15 0- 5G C. (60° Fahr.) as unity. In using it for reducing my ob- 
servations to their value at a common temperature, I adopted the same standard 
temperature, as involving the least amount of calculation. It has, however, the advantage 
over lower temperatures that the amount of the correction to be applied to each 
observation is much smaller than if such a temperature as 4° or 0° C. were chosen. 
Table VI. 
Copy of Hubbard’s Original Table for Fahrenheit’s Degrees. 
Temp. 
Dilatation. 
Temp. 
Dilatation. 
Temp. 
Dilatation. 
Temp. 
Dilatation. 
2*2 
0-99807 
o 
32 
0 99795 
50 
0-99895 
110 
1-00950 
23 
801 
33 
797 
55 
943 
120 
218 
24 
798 
34 
800 
60 
1 -ooooo 
130 
506 
25 
795 
35 
803 
65 
067 
140 
1804 
26 
793 
36 
806 
70 
142 
150 
2118 
27 
792 
37 
810 
75 
221 
160 
2460 
28 
791 
38 
814 
80 
309 
170 
2823 
29 
791 
39 
819 
85 
402 
180 
3192 
30 
792 
40 
823 
90 
503 
190 
3588 
31 
793 
45 
856 
100 
716 
200 
3993 
Table VII. 
Giving Hubbard’s Values for the Volume (called in the original “Dilatation”) 
AT EVERY DEGREE CENTIGRADE, THAT AT 15°'5G C. BEING UNITY. 
Temp. 
Volume. 
Temp. 
Volume. 
Temp. 
Volume. 
Temp. 
Volume. 
Temp. 
Volume. 
• 
1 _1 
0-99792 
. 
0 
795 
6 
0-99840 
12 
0-99927 
18 
1-00059 
24 
1-00224 
1 
799 
7 
853 
13 
947 
19 
086 
25 
256 
! 2 
804 
8 
866 
14 
967 
20 
111 
26 
288 
3 
812 
9 
878 
15 
987 
21 
137 
27 
320 
4 
820 
10 
893 
16 
1-00010 
22 
164 
28 
352 
& 
830 
11 
910 
17 
034 
23 
194 
29 
385 
30 
420 
1 Published in Maury’* Sailing Directions, 1858, I. p. 237. 
