The whinftone, ox bafaltic mixture of quartz
and hornblende, is uppermoft t and under
it is a learn of jafper, in fome places cu-
rioufly fpotted with iron. Here alfo occur
grit and limeftone ; with quartz and calcareous
fpär. When the whinftone is
in decompolition, it appears like a lava
that has been long expofed to the weather,
and much refembles the Derby-
fhire toadftonei The Pentland hills produce
petunfiy or the decayed felfpar ufed
in making porcelain ; and, according to
fome, adularia. Here are alfo confiderable
malfes of argillaceous porphyry.
From Edinburgh I returned by Carlifle
to Alfton, where there are feveral mines
belonging to Greenwich Hofpital ; from
the truftees of which, they are rented
by the Quaker company. They are
chiefly in limeftone; and are rake veins,
producing
producing a great quantity of lead ore, with
blende, calcareous fpar, &c.
Garrigiil gate, Tyne head, and Nent head,
are confiderable mineral countries. Coal
Clough, a great mine, is worked in limeftone,
and in the grit fometimes called
hazel; and alfo, which is lingular, through
a thin feam of coal. It produces large
quantities of lead ore, fluor, &c. There
is another confiderable mine of the fame
fubftances at Allons Head; both of thefe
mines, and many others, being the property
of the worthy Colonel Beaumont. The
mines in this quarter are conducted on the
molt fcientific principles, which their rich
produce can indeed well afford ; and the
agents are men of Ikill, and well verled
in mechanics. On proceeding fouthward,
a variety of mines appear in Weredale
and Teefdale, about Middleham and Ark-
l endale