WAVE OF HIGH WATER. 333 



irregular hours disappears when the facts are treated iii 

 relation to land- areas ; for whereas no existing land- area 

 is perfectly circular^ or has everywhere wide and uninter- 

 rupted ocean-boundaries^ or is free from the disturbing- 

 action of other areas — conditions essential to uniform pro- 

 gression of the wave, — it follows of necessity that anomalies 

 such as these may reasonably be expected. 



The nodal points which revolve round irregular areas 

 cannot be supposed to represent the entire differential 

 action. Every point where a departure from the essential 

 conditions exists will necessarily become the centre of a 

 local residual action ; the nodal points will merely represent 

 the leading features of each area, so far as that area tends 

 to conform to the required conditions. 



Judging from frequent coincidences in time, these ir- 

 regular tidal hours in many instances appear to be due to 

 the direct local action of the moon when crossing the meri- 

 dian of the place. 



In like manner interruptions in the continuity of the 

 surrounding ocean-spaces will lead to variations in the 

 velocity of the waves ; and this interruption, when extensive, 

 should culminate in simultaneous high water. 



It is not consistent with the scope of this paper to enter 

 upon other phases of tidal action; but it maybe permitted 

 briefly to allude to the circumstance that our mode of view- 

 ing the phenomena of the tides would lead to the conclusion 

 that mid- ocean tides should always be small, and that the 

 wave of high water should everywhere roll in nearly parallel 

 with the coast. Observation has proved that the facts are 

 in intimate harmony with these conclusions, although these 

 facts are directly at variance with the requirements of ex- 

 isting theories. 



In short, when approached from our stand-point, every 

 part of the phenomena of the tides will receive more or less 

 of elucidation ; and where anomalous results appear, it will 



