WAVE OF HIGH WATER. 327 



the tidal hours in each successive tract of coast be taken, 

 there is, in conformity with the law, a progressive though 

 somewhat irregular increase in the mean hour, amounting 

 in the whole to between 4 and 5 hours from the Sea of 

 Japan to the entrance of the Gulf of Siam. On the southern 

 coast of Asia there is, in the Bay of Bengal, an approxima- 

 tion towards a simultaneous high water ; but the tides are 

 very irregular in the Arabian Sea. In the eastern archi- 

 pelago the facts are not sufficiently numerous to reveal any 

 traces of systematic progression. 



Passing to continents in the southern hemisphere, we 

 shall proceed round each coast, as required by the law, in 

 the direction opposite to the motion of the hands of a watch, 

 the progressive increase of the hour being, as before, evidence 

 of conformity with the law. South America, being nearly 

 surrounded by open ocean, at first sight appears closely to 

 approach the most favourable conditions ; but it is impos- 

 sible to include the whole of the continent within one circle 

 approximating to the coast-line, and it therefore becomes 

 necessary to sever the northern part at the estuary of the 

 La Plata Biver, and to treat the southern prolongation of 

 this continent as an independent area. Neither of these 

 areas has uninterrupted ocean-boundaries. 



The hours of the northern area are as under : — 



h. m. 



Buenos Ayres, La Plata Biver . 3 53 



Isle of St. Sebastian , . . . 5 00 



Cape Frio 5 28 



Victoria, Espiritu«Santo Bay . 5 41 



Bahia 64 



Pernambuco ...... 75 



Cayenne 7 ^4 



Berbice . 8 20 



Demerara River 8 38 



