C 5 8 ] 
which at full lea there are ten and twelve feet of water.. 
From the fouthern fide of St. Martin’s, (mark’d^) 
in the map annex’d, there ftretches out a large IhoaL 
towards Trefcaw and St. Mary’s; and from St. Mary’s, 
a flat call’d Sandy-bar (mark’d C) fhoots away to meet 
it ; and between thefe two fhoals there are but four 
feet of water, in the chanel call’d Crow-found : All 
ftrong arguments, that thefo illands were once one con- 
tinued trad: of land, tho’ now, as to their low-lands, 
©ver-run with the fea and fand. Hiftory confirms 
their former union. “ The ifles Cafliterides (fays 
“ Strabo*) are ten in number, clofe to one another ; 
“ one of them is defert and unpeopled, the reft are 
“ inhabited.” But fee how the fea has multiplied 
thefe illands ; there are now reckon’d one hundred and 
forty : Into lb many fragments are they divided, and 
yet there are but fix inhabited. 
§ 3. But no circumftance can fhew the great al- 
terations, which have happen’d in the number and 
extent of thefe illands more than this ; viz. that the 
ifle of Sylley, from which the little duller of thefe 
Cyclades takes its name, is no more at prefent than 
a high rock, of about a furlong over, whofe cliffs 
hardly any thing but birds can mount, and whofe 
barrennefs could never fuffer any thing but fea-birds 
to inhabit it. How then came all thefe illands to 
have their general name from fuch a fmall and ufelefs 
plot? From the difpolition of the rocks and illets 
here, and allowing the alterations before fuggefted, 
we may anfwer this queftion, which would other- 
wife be extremely difficult to folve. 
From 
• Geogr. lib, 5. 
