nets the gilded fly;
Call the young Zephyrs to their fragrant bowers,
170 And stay with kisses sweet the Vernal Hours.
Where, as proud Maffon rises rude and bleak,
And with mishapen turrets crests the Peak,
Old Matlock gapes with marble jaws, beneath,
And o'er fear'd Derwent bends his flinty teeth;
175 Deep in wide caves below the dangerous soil
Blue sulphurs flame, imprison'd waters boil.

[_Deep in wide caves_. l. 175. The arguments which tend to shew
that the warm springs of this country are produced from steam raised by
deep subterraneous fires, and afterwards condensed between the strata of
the mountains, appear to me much more conclusive, than the idea of their
being warmed by chemical combinations near the surface of the earth: for,
1st, their heat has kept accurately the same perhaps for many centuries,
certainly as long as we have been possessed of good thermometers; which
cannot be well explained, without supposing that they are first in a
boiling state. For as the heat of boiling water is 212, and that of the
internal parts of the earth 48, it is easy to understand, that the steam
raised from boiling water, after being condensed in some mountain, and
passing from thence through a certain space of the cold earth, must be
cooled always to a given degree; and it is probable the distance from the
exit of the spring, to the place where the steam is condensed, might be
guessed by the degree of its warmth.

2. In the dry summer of 1780, when all other springs were either dry or
much diminished, those of Buxton and Matlock (as I was well informed on
the spot), had suffered no diminution; which proves that the sources of
these warm springs are at great depths below the surface of the earth.

3. There are numerous perpendicular fissures in the rocks of Derbyshire,
in which the ores of lead and copper are found, and which pass to
unknown depths; and might thence afford a passage to steam from great
subterraneous fires.

4. If these waters were heated by the decomposition of pyrites, there
would be some chalybeate taste or sulphureous smell in them. See note in
part 1. on the existence of central fires.]

Impetuous steams in spiral colums rise
Through rifted rocks, impatient for the skies;
Or o'er bright seas of bubbling lavas blow,
180 As heave and toss the billowy fires below;
Condensed on high, in wandering rills they glide