AECTIC SEAS.— PAET IV. NOETHUMBEELAND SOUND. 
327 
Diurnal Tide. 
1. Solitidal Interval, 
i=-4 h 11“ 
2. Solar Coefficient, corrected for Declination, 
S=5‘0 inches. 
3. Lunitidal Interval, 
^=- 8 * 8 “ 
4. Solar Coefficient, corrected for Declination, 
M=4’0 inches. 
Semidiurnal Tide. 
1. Mean Lunitidal Interval, 
High Water. Lew Water, 
h m h m 
4-0 7-05 6 35-35 ' 
2. Difference between Lunitidal and Solitidal Intervals, 
i m — ^=38 m . 
3. Approximate ratios of uncorrected Solar and Lunar Coefficients, 
^,=0-297 (Heights) 
= 0-421 (Intervals). 
Note A.— Added July 1, 1875. 
At the time of writing this paper I abandoned the attempt to determine the Lunar 
Diurnal Tide, in consequence of the breakdown of the observations which occurred in 
the neighbourhood of the 23rd June, which corresponds with one of the maxima of the 
Lunar Declination. This Tide may, however, he found from the tides of 8th and 9th 
June and 5th and 6th July, which also correspond to maxima of the Declination. The 
Lunar Diurnal Tide is the difference between the Total Diurnal Tide and the Solar 
Diurnal Tide, which is determined in the paper. 
In the following Tables, the Solar Diurnal Tide is calculated from the formula 
Solar Tide=3'58 cos(s+4 h ll m ), 
founded on the constants 
S=5-00 inches, 
4=-4 h ll m . 
