ON THE HAEMONIC ANALYSIS OF TIDAL OBSERVATIONS. 



Tide-table for Poet Blaie, 1885. 



A tide-table was computed for Aden for a fortnight, and the results 

 were found to be somewhat less satisfactory than those in the above 

 table. It must be remarked, however, that the sum of the semi-ranges of 

 the three diurnal tides K,, O, P is 2340 ft., and is actually greater than 

 the sum of the semi-ranges of the tides M2 and Sj, which is 2"265 ft. 

 Thus, at some parts of some lunations the semidiurnal tide is obliterated 

 by the diurnal tide, and there is only one high water and one low water 

 in the day. In this case it is obvious that the approximation, by which 

 we determine semidiurnal high and low water and apply a correction 

 for the diurnal tides, becomes inapplicable. In the greater part of our 

 computed table the concordance is fairly good ; bat the tide-predicting 



