MR MILNE ON A REMARKABLE OSCILLATION OF THE SEA. 637 



the sea traversed by the storm, must have been greatly and suddenly diminished ; 

 and thus, beneath the whirling aerial current, the waters of the ocean would be 

 heaped up, and form a sort of wave, which would advance in the direction of the 

 storm. But, for the reasons already given, it would move forward more rapidly than 

 the storm itself, and make way for the formation of another and another wave, 

 which would continue to advance towards the land, until the storm itself arrived 

 there. Accordingly, it is mentioned in the Penzance account, that the storm 

 reached the Cornish coast, shortly before the oscillation of the sea subsided. 



Thus, I conceive it possible at least to explain how, partly by the mechanical 

 pressure of the wind in the storm, blowing first in one direction, and thereafter 

 in an opposite direction, and partly by the sudden diminution of atmospheric 

 pressure accompanying its progress, the sea on the SW. coasts of England was 

 thrown into a state of oscillation. 



I confess, however, that it is somewhat more difficult to explain the oscilla- 

 tion on the Scotch coast on the afternoon of the same day. 



There are only two ways in which it seems possible to account for it. The 

 first is, by supposing that the agitation on the Scotch coasts was propagated like 

 the tidal wave, from those parts of the ocean where the English oscillation 

 originated. The other is, by supposing that the storm itself, on reaching the 

 Scottish seas, produced the same effects there as elsewhare. 



There is some difficulty, however, in adopting either explanation. 



In regard to the last, it will be observed that, whilst the oscillation com- 

 menced in the Firth of Forth between 1 and 2 P.M., the thunder-storm did not, 

 in its course northward, reach Scotland till some hours after ; and therefore it 

 could not have affected the German Ocean early enough in the day, to have pro- 

 duced an oscillation. 



In regard to the other explanation, the admissibility of it depends on the 

 place where the waves producing the flux and reflux were generated. Two places 

 may be found, either of which, as the supposed birth-place of these waves, would 

 suit the tune of their arrival in England and in Scotland. The one is in the 

 Atlantic Ocean, to the W. or NW. of Ireland ; for a tidal wave produced at this 

 place would reach the Cornish coasts and the Firth of Forth much about the same 

 time. The other place is about the Straits of Dover. But neither of these points 

 suit well the other conditions of the question, for this reason among others, 

 that the storm did not come from either the NW. or the NE. to Plymouth and 

 Penzance, but is distinctly proved, both by the observations there and by the 

 general progress of the storm, to have come from the southward. 



It is very probable, that the oscillation of the sea on the east of Scotland 

 was produced by another storm altogether, which raged over the German Ocean. 

 It appears that the whole atmosphere in this part of the globe, was about this time 

 violently disturbed. There is good evidence of there having been several very 



VOL. XV. PART IV. 8 I 



