
On the Tides of Key West. 307 
As the observations were only made hourly, and the inequality 
in the interval of high water is small, the minute changes from 
day to day conld not be expected to show themselves. The in- 
equalities were grouped according to the different declinations of 
the moon into fourteen periods, and the approximate formula, 
given by Mr. Lubbock, for the variation from the mean, was 
applied. The agreement with theory, as shown in the annexed 
table, is very close; G was taken as 115. 
TABLE No. 2. 
Comparison of the diurnal inequality of es. ater at Key West, with the formula 
tan 6 







Moon’s declination. — en oF Difference. 
- Minutes. Minutes Minutes. 
3 55 13 15 soccer 
AS 25 29 — 04 
11 30 48 47 01® 
15 45 61 64 — 03 
18 55 "4 48 — 04 
20 55 88 87 Ol 
21 30 100 91 09 
91 55 95 92 03 
20 15 84 85 —oO1 
17 30 83 72 1 
13 55 52 56 — 04 
9 15 87 38 — Ol 
5 15 25 21 04 
2 55 07 Be — O04 
— 23 
+ 29 
52 





The inequalities of time of high water were also arranged ac- 
cording to the moon’s age, but the agreement of the observation 
with the formula is not as close as in the former case, as must be 
the case from the small number of observations, and the variation 
of the inequality following chiefly the law of the declination. 
The law of change is still evident in the grouping, and the plus 
and minus quantities balance nearly. 
The discussion of the diurnal inequality in height will be re- 
sumed in referring to the diurnal wave, after noticing the decom- 
peuon of the curve of observation into a semi-diurnal and diur- 
eu : 
Decomposition of the curves of observation. 
curves of observation at Key West were deco — 
one representing the semi-diurnal and tle other the diurnal tide. 
The interval (E), which was in the former case assu o be 
