(183 ) 
In these values again the annual variations and the aperiodic 
disturbances are eliminated. 
(a + b — 2e) 
May —101.0 eM. 
June —106.4 > 
July —105.4 » 
August — 18.5 » 
September — Ot > 
October 44.9 » 
November TD > 
December 57.3 » 
January 5.7 » 
February — 37.3 » 
March — 65.9 » 
April — 22.8 » 
The double-periodie variation of these values, as computed by the 
method 1. sq., may be represented by the expression: 
27.575 cos 60° x — 14.015 sin GO°r. . . . « (5) 
From (4) we find: 
(1) + (2) = a = 2 K, Ry cos 30° cos (60° x — 60° — Cyx) 
(3) + (4) == b = 2 Ky Ry cos 30° cos (60° « + 60° — Cox) 
(5) + (6) = ¢ = 2 Ky Ry cos 30° cos (60° « + 180° — Cox) 
a+b —2¢= 6 K, Rg cos 30° cos (60° x — Car) « « - (6) 
This equation shows that, by this method, the constants of Ko 
can be determined from a periodic formula in which the amplitude 
is about 5 times larger than the value which has to be calculated. 
By equating the coefficients of (5) and (6) we find: 
Ks cos Coz = 5.558 Ky sin Cap = — 2.825 
K, = 6.24 em. Car = 333°3! 
hd 
e. The average monthly values of the water-level are found by 
correcting the mean values as obtained by direct computation for 
the influence of the tides S;, A] and P. From formulae (1) and (4) 
it appears that (for the actual hours of observation) the correction 
due to the influence of S, and Ks is nil; that for the single period- 
ical tides is given by the average values of formula (1) and (3) 
and is to be applied with inversed signs, 
