358 Prof. A. D. Bache on Tidal Observations. 
erpool. The difference between the greatest and least heights is 
0 
(0:220—0:047)=0:173. andE= >,,, =0:238: © 
also the greatest height 0:220=D+(E) x(1+A)=D-+ ‘325; and 
D=—0:10. 
; (0-07480)2 1 5 Oe HO 
OS Wt. (h).... 6506. Meee 
For the half-monthly inequality of the intervals, we have 
(A)xsin2g — -0:364x sin2g | 
1+(A)Xcos2g  1+0°364X cos2q’ 
and in the heights, 
h=—0°10+(E) x(A) xX cos (2y —29)+(E)cos2y 
= — 0:10+0-087 x cos (2 y —2¢)+0-238 x cos 2 y. 
The following table contains the half-monthly inequality of 
times deduced from the observations, and computed from the for- 
mula for tang 2 y, and the comparison of observed and computed 
tang 2 y= 
quantities, 
TABLE No, XVII. 
OL 2 Dhl a) EY re Te a ead 7 Lf of L 3° a ere 2 2) 
Mean from observation 12h. 35m. - ee 
C. 0. "O-C. * ) 
Q wv From formula. From observation. + 7 
h. m h. m hm. h. m. m m. &G 
o 30 o 08 1237 12: st 04 ee 
E30 23 oe a3 1: : 
2230 36 <2 00 It 19 ss es 
3 30 42 tr 33 ti. 4 ry a 
4 30 38 1 57 12 03 Oe oe oe 
5 17 © eee 12 24 3 
6 30 ¢ age | £5.98 14 
7 38 1 Ws 13 09 04 
8 a 42 13-17 1029 10 
g 30 36 a3 siz 13 05 06 
10 30 52 43-05 133205 o7 
Ir 3o 08 12° 43 13° 65 ae? 
+74 \-—72 
125 35™ not being the exact mean of the observed times, the + 
and — differences do not balance exactly. 
Diagram No. 9 shows the observed and computed results. The 
greatest and least heights correspond with the average interval, as 
they should do by Bernouilli’s theory. : oe 
The average interval corresponds to 0223" nearly, showing that 
transit E should be used instead of transit F. eee 
