290 Profefor WirriAMs on Earthguakes. 
by others ; and is agreeable to all the accounts that can be col- 
le&ted. And from thefe accounts of the fevéral phenomena of 
the earthquakes, and the obfervations that have been made upon 
them, I think »we may lay it down as a pretty certain fad, that 
the earthquakes of New-Englend have been caufed by fome- 
thing which has moved along under the furface of the coun try. 
What thus moved under, and hove up the fürface of 
the earth, was probably a firong elaftic vapour. This is 
inferred from the phenomena that have attended the earth- 
. | Among thefe phenomena, there were fome that preceded the 
earthquakes, and looked like a previous preparation. ln the 
, earthquakes of 1727 and 1755, in particular, it was evident, 
„that the: caufes by which they were produced, were dt work 
feveral days before they became ripe for an explofion. As tho’ 
fome grand fermentation was taking place in the bowels of the 
‘earth, the water, in feveral wells and fi prings, was uncommonly . 
altered in its motion, colour, fmell and quality. This was ob- 
ferved three or four days before there was any earthquake. No- 
thing could better agree with the origin and produ@ion of a 
fubterraneous elaftic vapour, than this circumftance: For how- 
ever fuch a vapour be generated, by mixture, fermentation or 
fire, it would require fome previous preparation, for its produc- 
tion, or before it would be collected in fufficient quantities to 
.caufe an explofion, or acquire fufficient force to move and fhake 
the furface of the earth. NE c di 
os noife Or roar, occafioned by the earthquakes, has always 
i: might have been cxpeéted from a fubterraneous 
xeu 
vapour, when fiercely driving along under the furface of the 
earth, What report might be expected froma ftrong elaftic 
š vapour, 
^ ole 
