320 
KEY. S. HAUGHTON ON THE TIDES OF THE 
Northumberland Sound (continued). 
Time. 1 
High. Water. 
Height. 
Low Water. 
Height. 
Diurnal Tide 
at 
High Water. 
Diurnal Tide 
at 
Low Water. 
1 1853. h m 
ft. in. 
ft. in. 
ft. 
ft. 
1 June 28. 6 40 a.m 
17 01 
0-302 
28. 1 38 „ 
15 8 
0-052 
28. 6 20 p.m. 
16 5 h 
0-453 
28. Midnight 
15 6 
0-240 
29 . 7 20 a.m 
17 3 
0-635 
29 . 2 10 p.m 
13 11 
0*297 
29. 7 40 „ 
14 9 
0-656 
30. 1 30 a.m 
13 11! 
0-125 
30. 8 30 „ 
15 4 
0-364 
30. 3 45 p.m 

13 11 
0-057 
30. 9 0 „ 
14 lOf 
0-193 
July 1. 12 40 a.m 
14 1 
0-107 
1 9 5,, 
15 2J 
0-135 
1. 4 35 p.m 
13 10 
0-172 
1 . 9 40 „ 
15 0 
0-088 
2. 4 20 a.m 
14 3 
0-229 
2. 9 38 „ 
15 2 
0-115 
2. 4 10 p.m 
13 8 
0-281 
2. 10 45 „ 
15 1 
0-000 
3. 4 45 a.m 
14 2 
0-339 
3. 10 30 „ 
14 111 
0-026 
3. 5 4 p.m 
13 4 
0-151 
3. 11 13 „ 
15 0 
0-026 
4. 5 0 a.m 
14 2 
0-448 
4. 10 45 „ 
14 1 If 
0-021 
4. 5 30 p.m 
13 21 
0-490 
5. 12 15 a.m 
15 1 
0-015 
5. (> 0 
14 2 
0500 
5. 12 45 P.M 
15 1 
0-031 
5. 6 15 ,, 
13 1 
0-511 
6. 1 0 a.m 
15 11 
0-073 
6. 8 0 „ 
14 0 
0-521 
6. 1 0 p.m 
14 10 
0 028 
6. 6 40 ,, 
12 9| 
0-521 
7. 2 0 A.M 
15 0 
7. 8 0 „ 
13 8 
The general expression for the Diurnal Tide is the following : — 
where 
D=S sin 2 cos (s— ? 5 )+ M sin 2 p cos (m — i m ), . 
D=height of tide, 
o', [Jj = Solar and Lunar Declinations, corrected for Age of Tide, 
s, m= Solar and Lunar Hour-angles, 
i s , i m — Diurnal Solitidal and Luni tidal Intervals, 
S, M= Solar and Lunar Coefficients, uncorrected for Parallax, &c. 
( 2 ) 
It would he impossible to obtain any result as to the Diurnal Tides from so short a 
series of observations, only for a lucky chance which simplifies the calculation at this 
station, and enables us to obtain the Solar Diurnal Tide, although it is not easy to 
