48g MR MILNE ON TWO STORMS WHICH SWEPT OVER 



" light airs from the NE., and clouds from SEy On the 29th, the entry in the 

 wind and weather column is, for the morning, " light wind N. by E., and clouds 

 from >S'. hy E.: — in the evening, " calm, slight rain, and clouds from south." On 

 the 30th, the air on the surface of the earth at Inverness was calm, but there were 

 ■' clouds and showers from west.'' These entries clearly indicate that, in that 

 northern latitude, the storm had become nearly expended, but was still faintly 

 existing, with all its characteristic features, in the upper regions of the atmo- 

 sphere. 



The effect of this gale on the waters of the Atlantic caused an unusually high 

 tide in almost all the parts in the Irish and English Channel. I find that, on 

 Wednesday night the 28th November, Newry, a town to the north of Dublin, was 

 inundated by the highest tide ever remembered. It was also a remarkably high 

 tide at Strangfbrd and at Donaghadee. On the same night, at Swansea the tide rose 

 seven feet two inches above its proper level. At Milfbrd, the tide rose higher than it 

 had ever been seen before. At Plymouth the tide rose over the quays, an occur- 

 rence said to have been unprecedented. On the Thursday forenoon the tide rose 

 in the Thames, and also at Greenock, Oban, Tobermory, and in Orkney, above 

 the level of the quays. At Oban and Tobermory, though these places are com- 

 pletely land-locked, and exposed to no swell from the ocean, all loose materials 

 lying on the quays were swept off by the mere rise of the tidal waters. The 

 height of the tide was there the more remarkable, as it was the season not of 

 spring but of neap tide. That this extraordinary elevation of the sea was occa- 

 sioned by the suddenly diminished pressure of the atmosphere, there is no doubt. 

 The effect of this diminished pressure, must have been to elevate the surface of 

 the ocean, and produce a sudden accumulation of waters, — a species of wave. The 

 accumulation would take place along the line of diminished pressure, or, in other 

 words, in the direction of the storm. This storm- wave (for such it may not impro- 

 perly be termed) moved therefore through the Atlantic in a N.NE. direction, and 

 happening to impinge on Great Britain and Ireland about the time of high- water, 

 caused the waters to overflow. That this wave had been produced not in the 

 British seas, but a great distance in the Atlantic, is evident from this, that it pre- 

 ceded by several hours the arrival of the most violent part of the hurricane, and 

 even the lowest depression of the barometer. Any undulation in the waters 

 of the ocean, it is well known, is very rapidly propagated. The earthquake at 

 Lisbon produced a wave in the Atlantic, which caused an unusually high tide on 

 the south coasts of England and Ireland. The first shock of this earthquake took 

 place at half-past eight in the morning. A wave produced by it, about five and 

 a half feet high, flowed into Kinsale harbour on the afternoon of the same day, 

 between 2 and 3 p. m. ; so that this wave must have travelled at the rate of about 

 180 miles an hour. It is, therefore, obvious, that a wave raised in the Atlantic, 

 by the same force which originates or accompanies a storm, may easily precede 

 the storm, and give warning of its advent. 



