WAVE OF HIGH WATER. 317 



liquid^ gas^ and the diffused matter of space, each layer 

 when superimposed in the above order_, and not otherwise_, 

 being in stable equilibrium at the surface of contact with 

 that which bounds it on either side, then the upheaval of 

 land-areas, and consequent denudation of the fluid cover- 

 ing, would render the lines of force directed towards such 

 land-areas less effective for gravitative action than those 

 directed towards ocean-areas j because, in the former, part 

 of the force would be expended in producing molecular 

 and other changes at the surfaces of abnormal contact, 

 and also because the attachment, so to speak, of the lines 

 of force at these surfaces of abnormal contact would con- 

 stitute an imperfect grip or gravitative hold of one surface 

 on the other, and any deficiency of whatever kind in the 

 effective value of the lines of cosmical tension directed 

 to land-areas would have to be compensated by an added 

 strain in those directed to ocean- areas. 



In other words, a residual portion of the differential 

 force would be expended in a direct pull or strain upon 

 the waters nearest the shores of land-areas, tending to 

 draw these waters upwards and towards the land as the 

 centre of perturbative action, and would thus give rise to 

 the wave of high water. 



By discussing from this point of view the hours of high 

 water at full and change for the principal places of the 

 globe, as given in the Admiralty Tide-Tables for 1863 (the 

 data being first reduced to Greenwich mean time), we 

 have arrived at the following law of the progression of the 

 wave of high water. 



In all land-areas in the northern hemispherej the wave 

 of high water tends to revolve round the coast in the di- 

 rection of the hands of a watch, and in like areas in the 

 southern hemisphere against the hands of a watch. 



Theoretically, this law should hold good in proportion 

 as land- areas approximate to the circular form, with wide 



