S 8 NATURAL HISTORY 
terribly, that a man there at work ran out of it, concluding it to 
be falling. Several perfons then in the mine, working fixty fathom 
deep, thought they found the earth about them to move, and heard 
an uncommon noife: fome heard the noife, and fek no tiemor ; 
others, working in a mine adjoining, called Kuel-Breag, were fo 
frightened, that they called to their companions above to be drawn 
up from the bottoms : their moorhoufe was fhaken, and the pad- 
lock of their candle-cheft was heard to (hike againft the ftaples.— 
To fhew that this noife proceeded from below, and not from any 
concuffion in the atmofphere above, this very intelligent captain of 
the mine c obferves from his own experience, that thunder was never 
known to affed the air at fixty fathoms deep, even in a fingle draft 
pierced into the hardeft done ; much lefs could it continue the 
found through fuch workings as there are in this mine, impeded in 
all parts with deads, great quantities of timber, various noifes, fuch 
as the rattling of chains, fridion of wheels and ropes, and dadnng 
of waters ; all which mud contribute to break the vibrations of the 
air as they defcend : and I entirely agree with this gentleman’s 
conclufion, that thunder, or any other noife from above in the at- 
mofphere, could not be heard at half the depth of this mine. 
This therefore could be no other than a real tremor of the earth, 
attended with a noife owing to a current of air and vapour proceed- 
ing upwards from the earth. 
I do not hear of any perfon in thofe parts who was fo rortunate 
as to be near any pool or lake, and had recolle&ion enough to 
attend to the motion of the waters ; but it may be taken for granted, 
that, during the tremors of the earth, the duids mud be more af- 
feded than the folids ; nay the waters will apparently be agitated 
when there is no motion of the earth perceptible, as was the cafe 
of our ponds and lake- waters in mod parts of Britain, on the id of 
November 1755 f : whence this comes is difficult to fay ; whether 
the earth’s bofom undergoes at fuch times a kind of refpiration, and 
alternately emits and withdraws a vapour through its more porous 
parts fufficient to agitate the waters, yet not diffident to ffiake the 
earth ; or whether the earth, during the agitation of the waters, 
does rock and vacillate, though not fo as to be fendble to man, is 
what I final! leave to future enquiry. 
Earthquakes are very rare in Cornwall ; this was but of ffiort du- 
ration, and did no harm any- where, as far as I can learn; and it is 
to be hoped not the foouer forgotten for that reafon, but rather re- 
membered with all the impreffions of gratitude fuitable to an inci- 
dent fo alarming and dangerous, and yet fo fparing and inoffenfive. 
f Philofophical Tranfaciions, 1756. 
CHAP. 
* Mr. John N ancarrow. 
