tions granite, of which a mountain may
appear as compact as a fmall piece.
He then returns to coal, and mentions
many inftruftive particulars which need
not here be repeated. The roofs of coal or
incumbent ftrata,. he divides into bafalt, as
at Hill Houfe, a mile fouth of Linlithgow
limeftone, poll ftone,or fandftone, doggeiv
band or ftrata, in balls of iron ftone, blaes,
or black fhiftus, alfo form a common roof;
but his further remarks on this fubjeft become
fcarcely intelligible from the imperfection
of his mineralogical knowledge and
vocabulary. The extent of the adit at Kil-
marton, which interfe&s above 60 beds of
coal, with different intervening ftrata, is
particularly difplayed.
Our author then enlarges on the declination
of the coal ftrata, and the various accidents
to which they are fubjed, particularly
their running fometimes like waves
but
but many of his remarks are very local and
minute.
He then proceeds to examine the extent
of coal fields which he finds do not pafs
through mountains, but on the contrary,
fometimes terminate at fome diftance from
them. The coal field to the S. E. of Edinburgh,
extends about fixteen miles from
Duddingfton to New Hall, where it terminates
at the bridge of Carlops, where the
river Efk leaves the Pentland Hills; and the
feams of coal, inftead of palling under the
hills, baffet or rife up in great confufion.
He concludes, p. 141, that the coal fields do
not ftretch under the mountains, but are
patches of different dimenfions like fields
of corn or grafs. That of Mid Lothian is
about fifteen miles in every direction, the
fourth forming the northern boundary.
After feveral repetitions which might
have been avoided by a proper diftribu-
n 4 tion