where it seldom exceeds six or eight feet,
though in other places it is much deeper; for
instance, if it has been impeded by any
thing in its progress, or if it has accumulated
in a valley or river. Nor have I been
able, though I took great pains to ascertain
the same, to discover, either in the vallies or
in the mountains, iron or sulphur, nor, indeed,
specimens of any combustible soil
different from that which may be found to
exist where volcanoes have never operated.
§ XVI.
The above must '‘be considered as an
answer to the first question, and I think I
have proved that the subterraneous fires,
which have broken out in various places,
have been the consequence of an eruption
and not of the earth itself being on- fire:
and this answer will naturally lead me to
Question con- another question, “ Where then
cerning the
place of eruption, are we to look for the original
source of the eruption?”
If we were to rely on the many oral
assertions, as well as on those that are committed
to writing, concerning the fire, we
should be led to conclude that its origin was
not in one but in many places. At least,
according to the generally received opinion,
one place must be allowed for the eastern
and another for the great western stream of
lava; for so did it appear to those persons
who in 1783 proceeded to some distance
up the mountains. In like manner the
tremendous pillars of smoke among the
mountains seemed to the inhabitants of the
plains to have various sources, and the same
also seemed to me to be the case last
summer, when I was .in Sida. From later
observations, however, I am induced to
adopt a totally different opinion. According
to a part of my instructions I resolved to
undertake a journey myself from the plains
to the place of eruption, notwithstanding
that every one represented the accomplishment
of my design as a thing impracticable
on account of the great distance, ’the badness
of the roads, the fresh streams, the impassable
rivers, the intolerable heat, the
dreadful smoke, the suffocating smell of
sulphur, the want of grass and forage for
our horses. All these, however, could not