ANDES.
that is impracticable, sometimes surmount them
by bridges, and sometimes avoid them by means
of a path cut along the shoulder of the overhanging
height.
With respect to the mountain-torrents, Herndon,
after leaving Antarangra behind him, was enabled
to avail himself chiefly of this resource. ¢As far as
the traveller,” says he, ¢is concerned, there are not,
on the route we have travelled, two ranges of the
A.—that is, he has not to ascend and descend one
range, and then ascend and descend another. From
the time that he crosses at Antarangra, his progress
is downward, till he reaches the plain. Really,
however, there are two ranges. The streams from
the first or western range have broken their way
through the second, making deep gorges, at the
bottom of which the road generally runs, and leaves
the peaks of the second range thousands of feet
above the traveller’s head.’
In addition to the essential perils of such a
course, Herndon encountered, on one occasion, an
incidental danger, which he thus describes—the
scene being a mnarrow path on the shoulder
of an almost precipitous hill: ¢Mr Gibbon was
riding ahead. Just as he was about to turn a
sharp bend, the head of a bull peered round it on
the descent. When the bull came in full view, he
stopped ; and we could see the heads of other cattle
clustering over his quarters, and hear the shouts of
the cattle-drivers, far behind, urging on their herd.
I happened to be abreast of a slight natural excava-
tion ; and dismounting, I put my shoulder against
my mule’s flank, and pressed her into this friendly
retreat ; bub I saw no escape for Gibbon. The bull,
with lowered crest and savage look, came slowly on,
and actually got his head between the perpendicular
wall and the neck of Gibbon’s mule. But his saga-
cious beast, pressing her haunches hard against the
rock, gathered her feet close under her, and turned
as on a pivot. This placed the bull on the outside ;
and he rushed by at the gallop, followed in single
file by the rest of the herd.
In the bridging of the mountain-torrents, a good
deal of rude ingenuity is displayed. Sometimes
chains are suspended from side to side; and some-
times a rough flooring is laid between projecting
beams from either bank, which have previously been
fixed as solidly as possible. Nature also has done
something in this respect to help man, having thrown
two bridges of her own over a fearful chasm at
Icononzo. The torrent, which they span, falls down
a beautiful cataract into a murky crevice—the noisy
haunt of nocturnal birds. At a height of 400 feet
above the foaming waters, the two bridges hang in
mid-air, both of them, apparently, though in differ-
ent ways, the work of an earthquake. The upper
one is merely a fragment of the original sandstone,
which must have resisted the shock that formed the
rent; while the lower, probably the most singular
arch in the world, consists of three detached rocks,
so adjusted as to support each other.
The loftiest pinnacles of the A., when viewed
from the table-lands, and, still more, when seen
from the crests of the passes, lose, to the eye of
the beholder, much of their real altitude. Under
such circumstances, not a single mountain presents
the actual dimensions of Mont Blane, as over-
hanging the Vale of Chamouni. It is only from
a distance—best of all, perhaps, from a good
offing in the Pacific—that the A. appear in all
their gigantic proportions. Standing thus on their
pedestal, the most rugged and colossal in nature,
they almost realise to the spectator the highest
Pyrenees piled on the highest Alps; while, to
enhance the grandeur of the scene, the igneous
action, which has heaved the chain into existence,
240
is here and there adding to its stature a pillar of
smoke and flame.
The geology of the A. is as yet very little
known. It is more than half a century since Hum-
boldt travelled through these mountains, and to
him we are even now chiefly indebted for our
knowledge regarding them. At that time, geology
was in 1ts infancy—its language had not been
formed, its classification, at least as it now exists,
was unknown, and its facts were mixed with absurd
and now long-exploded theories ; it could, in fact,
scarcely be called a science. It is fortunate that as
regards the materials constituting the great mass of
the A. range—the igneous rocks which form its
back-bone, and the metamorphic rocks which form
its great bulk—our knowledge was almost as exten-
sive and explicit 50 years ago as it is now, and
therefore, in respect to them, Humboldt’s observa-
tions are as good as if made but yesterday. Not so
as regards the more recent sedimentary formations,
The value of fossils was not then known, and the
vaguest ideas prevailed as to the chronological
order of the stratified rocks. Hence descriptions
written at that time are almost valueless to modern
science. A few scattered notes may be gleaned from
the small number of intelligent travellers who have
recently visited these mountains; and to them we
are obliged for any of the facts we are able to give
regarding the deposits referred +o.
The elevation of the A. took place at an epoch
anterior to the formation of the Rocky Mountains
of North America, which are geographically a con-
tinuation of them. They are composed, to a very
large extent, of -stratified metamorphic rocks. It
is remarkable that granite occurs in them not as an
unstratified plutonic rock, but only intercalated
with the other members of the stratified azoic series.
The true igneous rocks belong either to the trappean
or volcanic divisions. The grand ridge is everywhere
covered with one or other of the varieties of trap
(greenstone, clinkstone, basalt, or porphyry). Thes
are often broken into columns, and appear at a dis-
tance like ruined castles, producing a very striking
effect.
Bursting through the trap-rocks, there are a num-
ber of volcanoes covering their summits with more
recent igneous rocks. Among the mountains spe-
cified above as to altitude, Yanteles, Corcobado,
Minchinadom, Antuco, Gualtieri, Arequipa, Cotopaxi,
Antesana, and Pichincha belong to this class. Fifty-
one volcanoes have been described as existing
throughout the whole range. The mountains of
Ecuador are so extensively and continuously of
volcanic origin, that they have been regarded as
different safety-valves of one and the same burnin g
vault. It is generally maintained that there is a rela.
tion between the height of a volcano and its activity
and the frequency of its eruptions. Thus, Stromboli
(2957 feet) has continued in a state of activity since
the earliest ages, serving the purpose of a light-house
to the navigators of the Tyrrhenian Sea; while
Cotopaxi (18,887 feet) and Tunguragua (16,579 feet)
have been active only once in a hundred years.
Many of these 51 volcanoes have consequently not
yet been observed by Europeans in an active state.
In the Quito district there are 10 active, and 7 of
doubtful activity ; in Peru and Bolivia, the numbers
are 9 and 3; in Chili, 17 and 5 : making in all 36
active, and 15 about which there is some uncer-
tainty as to their activity., Another characteristic
of these volcanoes, resulting from their gigantic alti-
tude, is that few of them emit streams of lava,
Thus Antisana is probably the only one in the Quito
range that has ejected lava. The force, however,
which is repressed apparently by the immense super-
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