SIR a. B. AIRY ON THE TIDES AT MALTA. 
127 
Means, for every group of three tidal hours, of the six half-hourly elevations of the 
tidal water in each of these groups, recorded at Malta, 1871 and 1872 — continued . 
Commencement 
of the Tidal Day, or 
Zero of Tidal Time, 
in Malta Mean 
Solar Time. 
No. of Group. 
Mean of 
Six 
Elevations. 
Commencement 
of the Tidal Day, or 
Zero of Tidal Time, 
in Malta Mean - 
Solar Time. 
No. of Group. 
Mean of 
Six 
Elevations. 
Commencement 
of the Tidal Day, or 
Zero of Tidal Time, 
in Malta Mean 
Solar Time. 
O 
O 
o 
6 
Mean of 
Six 
Elevations. 
1871 h. m. 
in. 
1872 h. m. 
in. 
1872 h. m. 
in. 
April 28.. 20 18 
1 
12T5 
June 10 . . 16 50 
1 
13-47 
July 6 . . 2 30 
i 
2 
12-02 
2 
10-43 
2 
3 
9-88 
3 
10-80 
3 
10-47 
4 
8-95 
4 
12-85 
4 
14-22 
5 
10-68 
5 
14-48 
5 
16-33 
6 
11-35 
6 
12-20 
6 
12-33 
7 
8-70 
7 
10-90 
7 
9-35 
8 
8-12 
8 
12-73 
8 
13-27 
April 29.. 21 42 
1 
11-57 
June 27 . . 19 20 
1 
13-93 
July 29.. 21 42 
1 
15-03 
2 
11-87 
2 
13-35 
2 
13-70 
3 
8-63 
3 
10-87 
3 
11-93 
4 
8-85 
4 
11-07 
4 
12-47 
5 
12T0 
5 
13-10 
5 
13-95 
6 
12-18 
6 
12*22 
6 
11-72 
7 
7 
10-10 
7 
8 
8 
11-02 
8 
1872 
June 8 . . 15 39 
1 
June 29.. 21 26 
1 
14-52 
Aug. 29.. 10 16 
1 
16-48 
2 
2 
13-65 
2 
16-52 
3 
7-85 
3 
10-72 
3 
12-83 
4 
11-33 
4 
1207 
4 
13-73 
5 
12T8 
5 
]3-77 
5 
16-37 
6 
8-85 
6 
12-68 
6 
7 
7-98 
7 
10-80 
7 
8 
11-07 
8 
12-20 
8 
June 9 . . 16 14 
1 
12-15 
June 30 . . 22 26 
1 
15-70 
2 
9-67 
2 
15-55 
3 
9-88 
3 
12-57 
4 
12-87 
4 
12-13 
5 
13T.0 
5 
15-35 
6 
10-82 
6 
14-48 
7 
9-53 
7 
11-02 
8 
11-75 
8 
Section III . — Treatment of the Means of the Grouped Measures , in order to express the 
Elevation of the Water by the Combination of Mean Height with Semidiurnal and 
Diurnal Tides. 
Put Gl, G2 . . . G8 for the successive means of grouped measures, as exhibited 
in the last table, for any one tidal day. And put 6 for the tidal angle, proportional to 
the time, whose value is 0 at the commencement of the tidal day, and is 27 r at 
the end of it. Then the values of 6 for the six measures of the first group 
are 48’ % 4^’ ^iid assume that any tidal elevation is to be expressed 
by 
