48 
gray or granite sand, extending all the way into the shores of Bri- 
tanny, which are also granite. 
The Sole-bank, which lies about five leagues within the edge of 
the soundings, about as large as Cornwall, and 180 feet over 
the general level is mostly fine white sand and black specks, evi- 
dently a fine grained granite country. ‘To the east of this, a large 
tract lies on the south side of the fair way distinguished by coarse 
red sand, stones, and gravel. This is just what we might expect 
from the disintegration of the red conglomerate sandstone, which 
covers the primary rocks, and is succeeded by the limestone ; and 
accordingly, immediately when we pass this red stony tract, we 
enter on the great shell bed, which, although not noticed particu- 
larly to the westward of the red tract, continues all the way up the 
middle of the channel, until we fall in with the chalk country of 
the south of England. 
The shelly tract spreads away to either side of the red sandstone, 
westward, in two narrow streaks ; and, by keeping within the nor- 
thernmost of these, we avoid falling into the Irish channel. And, 
to the north of this, is a tract of gray sand with black specks, 
which may be traced all the way from the Solebank aforesaid into 
the isles of Scilly ; shewing evidently its connection with the gra- 
nites and mica slate of those isles and Cornwall. 
To the south of this, between the shell bed and the Scilly islands, 
isan extensive tract of brown sand. I can only suppose a disinte- 
grated graywacké, or brown slate rock, or killas, as it would be named 
in Cornwall; especially as the same character obtains to the south 
of the western part of Ireland, where it seems an extension of the 
brown slate country of Cork and Kerry. 
When, so far in as the line from Cork to Ushant, we have about 
sixty fathoms water, the line however which marks that depth in- 
