with a variety of earthy fubftances, thé
ftrata being of various thicknefs, in different
fituations where the mine Is funk. Firft
vegetable earth a few inches, then 12 feet
argillaceous blüeifh earthy matter, 44 to 50
feet decompofed black earthy fhiflus, a bed
of 6 feet of fhiftofe hard coal, under which
is a ftratum of argillaceous indurated clay,
from 10 to 12 feet, which is incumbent on
a bed of fine coal, 8 to 10 feet thick.
In the neighbourhood, to the north eaft,
is a large mountain of limeftone, containing
a confiderable portion of magnefian
earth, at Breedon, on the edge of Leicefter-
fhire, ufed for land and building purpofes $
its colour being redifh grey : in it are fparry
veins, and fometimes fmall firings of galena.
Proceeding north, the coal does not make
its appearance until you arrive north eaft of
Derby, a diftance of twelve to fourteen
miles j ï here a large traCt of country is
enriched
enriched by this valuable Commodity, as at
Morley, Hallam, Smalley, Denby, Heynor,
Pentridge, Alfreton, Chefterfield, Baflow,
and many other places, amongft which are
fome iron works*
The coal is found at various depths ; and
where a horizontal gallery can be driven
into the coal, it is certainly much more
convenient and lefs expenfive than the general
mode of finking fhafts.
The national benefit arifing from this
article is beyond eflimation; canals are cut
to tranfport it into thofe diftri&s in which
no coal is found, by which many thoufands
find employment. Goals may be bought at
the mine for 5s. 6d. per ton, or at 10s. per
ton conveyed a few miles.
The great improvement which the iron
manufactories of this country have received
by charring or coaking the coal, now frequently
adopted, gives reafon to hope that
c they