80 Intelligence and Miscellaneous Articles. 



This vapour-ocean constitutes an intermediate state of matter in un- 

 stable equilibrium with other states at all surfaces of contact. By 

 interactions arising thereout, the simple static conditions of force 

 existing prior to land-upheaval are now, in the view of the author, 

 partly replaced by more complex phases of force ; and thus light, heat, 

 electricity, and magnetism, which are expressions of these complex 

 phases, have their root in local reactions between unstable states of 

 terrestrial matter at surfaces of abnormal contact when under the 

 tension of cosmical force — just as all these "imponderable elements" 

 are evoked in the voltaic battery by surface reactions of dissimilar 

 solids and liquids in presence of atmospheric tension. In short, the 

 ceaseless molecular changes and local motions of terrestrial matter 

 would, on this hypothesis, be mainly referred to the differential 

 action arising out of land-upheaval. 



Recurring to the " w r ave of high water " which formed the special 

 subject of the paper, another phase of the present residual of that 

 differential action would give rise to the tidal motions of ocean sur- 

 faces, the perturbative action centring on land areas, and attaining 

 a maximum value on the shores of those areas. By discussing the 

 hours of high water at full and change for the principal places of the 

 globe, given in the Admiralty Tide Tables for 1863 (the data being 

 first reduced to Greenwich mean time), the author arrived at the 

 following law of the progression of the wave of high water : — 



In all land areas in the northern hemisphere the wave of high water 

 tends to revolve round the coast in the direction 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 uninterrupted 

 ocean spaces all round. In a perfectly circular area of this kind, the 

 differential action would have points of maximum and minimum effect 

 on opposite shores at every instant, — these together forming a nodal 

 line, both ends of which would move simultaneously round the coast 

 as the moon passed across the heavens, the wave of high water being 

 everywhere the instantaneous expression of the differential force at 

 its nodal point of maximum action. 



By enclosing the continents and land areas which approach near- 

 est to the prescribed conditions within one or more circles intersecting 

 the salient parts of the coast, the author showed that whenever any 

 systematic progression of the hour of high water could be distinctly 

 traced, that progression is almost invariably in the required direction. 

 Owing, however, to the irregular shape of all existing land areas, to 

 the impossibility of including some of these in a single circle approxi- 

 mating to the coast line, and to the way in which some large areas 

 are massed upon others with little or no intervening ocean spaces, 

 many instances of anomalous results are found; and yet, when 

 rightly considered in relation to disturbing causes, even these tend 

 indirectly to confirm the method of grouping the data of tidal hours 

 in relation to land areas as causal centres. — Proceedings of the Man- 

 chester Literary and Philosophical Society, Physical and Mathematical 

 Section, April 30, 1863. 



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