NARRATIVE OF THE CRUISE. 
953 
0’9937 = 0'001332 ; but standard water, by table, at 18°'3 has the density 1-02534, and 
1‘02534 + 0‘00133 = 1’02667, which is the required density at 18 0, 3. 
Second example — Given the density at 18°‘3 C. as 1*02667, find that at 15°"56 C. 
Answer: At 18°\3 C. the density of the given water is 1 ‘02667 — 1-02534 = 0-00133 
heavier than the standard; hence the corresponding difference at 15° ‘56 C. is 
0‘00133+ = by table to 0‘00133 x 1‘0063 = 0‘00134, hence the result sought = 
1-02600 + 0‘00134 = 1‘02734. 
Making use. of Table I., Table II. has been compiled; it gives the densities of three 
waters, A, B, and C, for every whole degree Centigrade. B is the standard water of 
Table I., and its density at 15 0, 56 C. is l - 026. The density of water A is 1-025 and 
that of Cis 1‘027. Table III. is identical with Table II., with this difference that the 
values are given for every degree of Fahrenheit’s scale between 32° and 88°. 
By means of one or other of these tables a density observed at any temperature can 
be reduced to its value at the standard temperature of 60° F. (15°"56 C.). 
The following table has been compiled from Professor Dittmar’s Memoir, giving the 
percentage of chlorine, or rather of halogen calculated as cldorine, in a kilogramme of 
water of different densities, and his coefficient (180 "5 84) for the proportion of total salts 
to 100 parts of halogen calculated as chlorine. The results for chlorine have been 
reduced to their values in grammes per litre measured at 60° F., and those for the total 
salts to grammes per litre and ounces per gallon, both measured at 60° F. 
Density at 60° F. 
(15“'-56 C.). 
Halogen calculated as Chlorine. 
Total Salts. 
Grammes per 
Kilogramme. 
Grammes per 
Litre at 60° F. 
Grammes per 
Kilogramme. 
Grammes per 
Litre at 60° F.’ 
Ounces per 
Gallon at 60° F. 
1-02200 
16-51 
16-87 
29-814 
30-469 
4-865 
300 
17-23 
17-62 
31-114 
31-829 
5-085 
400 
17-95 
18-36 
32-414 
'33-191 
5-305 
500 
18-67 
19-13 
33-713 
34-555 
5-526 
600 
19-39 
19-88 
35-015 
35-925 
5-746 
700 
20-11 
20-65 
36-315 
37-295 
5-966 
800 
20-83 
21-40 
37-616 
38-668 
6-187 
One of the most interesting results of the analyses by Professor Dittmar of a very 
large number of the samples brought from different localities passed over during 
