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LX XV. ExtraEl of a Letter to the Reverend 
Thomas Birch, D, D . Secretary to the 
Royal Society , from Mr. Abraham Mafon* 
of Barbadoes, relating to an extraordinary 
Agitation of the Sea there , 31/? of March 
and an epidemical Diforder in that 
S I R, Barbadoes, May 30, 1761.. 
Read March 11, T Cannot omit giving you an account 
JL of a very extraordinary motion of 
the fea, (I think it was the laft day of March paft) 
not unlike that, remarked here, on the dreadful day 
of calamity, which happened at Lifbon ; with this 
difference,, the- laft was not fo fudden as the former, 
in the flux and reflux; which fufficiently {hews, that 
the fhock muff have been greater, that occafioned it, 
as it is moft likely they proceeded from the fame caufe, 
(viz.) that of an earthquake, whereby fome place, 
under the furface of the fea, has been funk. 
According to the beft obfervations that could be 
made, the tide ebbed and flowed, in about eight mi- 
nutes, between eighteen inches and two feet, and 
continued fo three hours, regularly decreanng till 
night, when it Was no more obfervable. 
It is very remarkable, that, fince that time, the 
iiland has been in a very deplorable condition, having 
fuffered under the fever eft colds, that have been ever 
known. The diftrefs has been fo general, that X 
may venture to affert, (with confidence) that nine- 
