C 52 ] 
on. What the two firft trees were, it was not eafy 
to diftinguifh, there being not a fufficiency remaining 
of the firft, and nothing but roots of the fecond, 
both pierced with the teredo, or augur-worm. Round 
thefe trees was fand, about ten inches deep, and then 
the natural earth, in which thefe trees had formerly 
flourifhed. It was a black marfh-earth, in which 
the leaves of the j uncus were intirely preserved from 
putrefaction. Thefe trees were 300 yards below 
full-fea-mark $ and, when the tide is in, have at 
leaft 1 2 feet of water above them : and doubtlefs 
there are the remains of other trees farther towards 
the fouth, which the fea perpetually covers, and 
have more than 30 feet water above them. But 
thefe are fufficient to confirm the ancient tradition 
of thefe parts, that St. Michael’s mount, now half 
a mile inclofed with the fea, when the tide is in, 
flood formerly in a wood. That the wood confifted 
of oak, very large, hazel and willow trees, is beyond 
difpute. That there has been a fubfidence of the 
fea-fhores hereabouts, is hinted in my letter to you, 
p. 9 2 j and the different levels and tendencies, which 
we obferved in the pofitions of the trees we found, 
afford us fome material inferences, as to the degree 
and inequalities of fuch fubfidences in general ; as 
the age, in which this fubfidence happened (near 1000 
years fince at leaft) may convince us, that when 
earthquakes happen, it is well for the country, that 
they are attended with fubfidences j for then the 
ground fettles, and the inflammable matter, which 
occafioned the earthquake, has no longer room to 
fpread, unite, and recruit its forces, fo as to create 
frequent and fubfequent earthquakes : whereas, where 
there 
