ty ee TRE 
( 195 ) 
; Wee enn . * » ‘ 
The remaining differences for all months are given in the following 
table, in which half mm. have been neglected; the months with 
ice are underlined. 
Month 1884 1885 1886 | 1887 | 1888 | 1889 | 1890 
January | 1d | Lh Ravan Hil DA | NS 20 
February | 9 | NA OU | aa nd 
More | Gp ENT | ad ee 
Nici seen OET NE OE ON LST 
Pes espe Ee NL ping 
dt i ec eae aR 
July dje ee ae Sep serge 
Ed a Cale A ee Wa 
Benen Oe ud adel Te by) ed | 
October apesdan ure bes Ws) seep tate 2216 
November | —6 | 7 ie le 3 3 
December | —6+ 3] 121 14| 24] .0| —80 
The mean error of the sea-level for all months, those with ice 
excepted, is 6,0 mm. Ll computed this mean error also on the sup- 
position that the second correction is 1/,, or 1/5, of V + E + 130. 
The mean error was found to be respectively 6,3 and 6,1 mm. 
When the value of Z is deduced from the heights at 2 and 8 o’clock 
and a mean correction 1/, (height at 5 + height at 11 — height at 
8 — height at 2) is applied, the mean error of Z has been found to 
be 8,8 mm. It seems therefore that the deduction of Z from the 
height at half-tide gives more exact values, than the deduction from 
the heights at 2 and 8 o’clock. 
Hence the value A for Delfzyl, after applying the above-mentioned 
corrections, the sun’s longitude being p and the correction for the 
presence of ice Y, is: 
AZ U ASE) = 193 4 Vis (VE A8750) 
— Yo; (V + E+ 130) + a, cos (py) + Y, 
y being a constant angle. 
Or: A=5 4+ 7/95, V — 8/75 E+ aj cos (p—y) + Y. 
