prevale?it Disorders, fyc, with Volcanic Emanations, 151 



The tide of the 29th was imputed to a sudden change of wind 

 from s.w. to n.e., in addition to a hurricane and floods from 

 the country. Major Rennel has observed {Phil. Trans., 

 1809) that high winds from w. and s.w., blowing into the 

 chops of the Channel, may force a greater body of water than 

 usual through the Straits of Dover, and so cause extraordinary 

 tides north of that place ; and he says that, in storms at the 

 entrance of the Channel, the surface of the water is often ele- 

 vated to 30 ft., when, at common spring tides, it is only 20 ft. 

 This, no doubt, will satisfactorily explain many of the great 

 variations in the tides on our coasts ; but I do not think that 

 this can apply to what took place at Leith (where the wind 

 was not high), or even at Poole, in Oct. 1833, notwithstand- 

 ing the hurricane which blew off Scilly ; for a high wind might 

 elevate or retard a tide, but could scarcely produce an inter- 

 change of tides, or throw in a sudden supply of water into a 

 particular spot, while the other harbours were not materially 

 affected. I, therefore, venture to believe that there was some 

 submarine convulsion causing a temporary alteration in the 

 level of the sea, such as often takes place in earthquakes. As 

 a striking confirmation of my conjecture, I find that Au- 

 vergne was at this very time shaken by a severe earthquake. 

 (Vide Memoir e de M. VAbbe Croizet, on the subject.) On 

 March 7. 1833, while there was a perfect calm, and the sea quite 

 smooth, the tide ebbed so greatly at La Hogue as to leave 

 the roadstead dry ; and several parts of the vessels destroyed 

 there by Admiral Russel (on May 29. 1692) were exposed 

 and taken up ; together with six pieces of cannon and several 

 cartloads of shot, which were found in good condition * : 

 there being no record, since that action, of such a great reces- 

 sion of water there (JV. M. M. s Dec. 1833.) On Oct. 3. 

 1764 (a year before introduced) occurred the lowest ebb in 

 London, and the highest flood at Ostend, ever known : the 

 latter town was under water. No cause, such as a westerly 

 wind, was assigned ; but, probably, that was the real cause : 

 and this fact strengthens, on that supposition, what has been 

 before said of the winds of that period. Sept. 28. 1764 pro- 

 duced the highest tide of the time at London. So, on Oct. 31. 



* This is not the only instance of discoveries made recently by the 

 effects of the elements. During the gales in Jan. 1 834, by the action of 

 the sea, part of the treasure of a Spanish galleon (wrecked shortly after 

 the conquest of America by the Spaniards) was found on the Rhosily 

 Sands, near Wormshead. About the same time, a gold ring and other 

 things were thrown up near Lyme, which had been buried more than a 

 thousand years. The Chesil Bank was so disturbed at that time, that 

 great quantities of coins, wrecked there nearly two hundred years since, 

 were picked up by the country people. 



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