REPORT ON THE COMPOSITION OF OCEAN-WATER. 
87 
To find a value for this quasi constant, I took the mean of all my 315 values of 
X 1 — X, which came to — (P037. This I subtracted from (i.e., I added -f 0*03 7 to) all the 
entries, and arranged the remainders as follows, according to their magnitudes. 
Table XI. 
Classification of the Observational Errors in Buchanan’s Values f. 
Numerical value of 
Number of errors in interval. 
Total number of 
error in units of the 
third place. 
A. 
Positive. 
Negative. 
Total. 
errors less than 
± A. 
Oto 19 
20 
32 
18 
50 
50 
20 to 39 
40 
32 
24 
56 
106 
40 to 59 
60 
19 
28 
47 
153 
60 to 79 
80 
22 
17 
39 
192 
80 to 99 
100 
12 
22 
34 
226 
100 to 119 
120 
7 
12 
19 
245 
120 to 139 
140 
12 
12 
24 
269 
140 to 159 
160 
9 
7 
16 
285 
160 to 179 
180 
7 
7 
14 
299 
180 to 199 
200 
2 
6 
8 
307 
200 to 219 
220 
5 
0 
5 
312 
220 to 239 
240 
2 
1 
3 
315 
161 
154 
315 
315 
By direct counting of the individual errors in the original table, which gave them all 
as an ascending series, the “probable error ” lies between ±0*061 and±0'062, And 
again, by direct counting, there are 249 cases (out of the 315) where the error is less 
than ±0*123 ; hence the probability of an error taken at random being less than twice the 
249 
probable is, by counting, = 2^5 = 0*79. Theory demands 0*82. 
The numbers y 1 were calculated from Buchanan’s results for 4 S, by means of Table 
VIII. ; but in ww-doing the vacuum correction which Buchanan’s specific gravities contain. 
