Valparaiso--Passage of Andes by Portillo pass--Sagacity of
mules--Mountain torrents--Mines, how discovered--Marine alluvium
in valleys--Effect of snow on surface--Geology, fossil shells,
double range, two periods of elevation--Red snow--Winds on the
crest--Snow thawing in pinnacles--Dry and clear atmosphere
--Electricity--Pampas--Zoology of opposite sides of Andes--Uniformity
of Patagonia--Locusts--Great bugs--Mendoza--Uspallata--Silicified
trees in vertical position--Indian ruins--Change of climate
--Earthquake arching bed of river--Cumbre--Valparaiso.
PASSAGE OF CORDILLERA.
MARCH 7TH, 1835.--We staid only three days at Concepcion, and then
sailed for Valparaiso. The wind being northerly, we only reached the
mouth of the harbour of Concepcion before it was dark. Being very
near the land, and a fog coming on, the anchor was dropped. Presently
a large American whaler appeared close alongside of us; and we heard
the Yankee swearing at his men, to make them keep quiet, whilst he
listened where the breakers were. Captain FitzRoy hailed him in a
loud clear voice, to anchor where he then was. The poor man must have
thought the voice came from the shore: such a Babel of cries issued
at once from the ship--every one hallooing out, “Let go the anchor!
veer cable! shorten sail!” It was the most laughable thing I ever
heard. If the ship’s crew had been all captains, and no men, there
could not have been a greater uproar of orders. We afterwards found
that the mate stuttered. I suppose all hands were assisting him in
giving his orders.
On the 11th we anchored at Valparaiso; and two days afterwards I set
out on an excursion to cross the Cordillera. I proceeded to Santiago,
where Mr. Caldcleugh most kindly assisted me in every possible way,
in making the little preparations which were necessary. In this
immediate part of Chile there are two passes across the Andes to
Mendoza, and the plains on the opposite side. The one most commonly
used, namely, that of Aconcagua, or Uspallata, is situated some way
to the northward of the capital: the other, called the Portillo, is
to the southward, and less distant. The latter is, however, rather
more lofty, and from the double chain, more dangerous during a
snow-storm. For these reasons it is but little used, especially late
in the season.
MARCH 18TH.--We set out for the Portillo pass. Leaving Santiago we
crossed the wide burnt-up plain on which that city stands, and in
the afternoon arrived at the Maypo, one of the principal rivers in
Chile. The valley, at the point where it enters the first Cordillera,
is bounded on each side by lofty barren mountains; and although not
broad, it is very fertile. Numerous cottages were surrounded by
vines, and by orchards of apple, nectarine, and peach trees; the
boughs of the latter breaking with the weight of the beautiful ripe
fruit.
In the evening we passed the custom-house, where our luggage was
examined. The frontier of Chile is better guarded by the Cordillera,
than by the waters of the sea. There are very few valleys which lead
to the central ranges, and, except by these, the mountains are far
too steep and lofty for any beast of burden to pass over them. The
custom-house officers were very civil; which was perhaps partly owing
to the passport which the President of the republic had given me; but
I must also express my admiration at the natural politeness of almost
every Chileno. In this instance the contrast with the same class
of men in most other countries was strongly marked. I may mention
an anecdote with which I was much pleased at the time. We met near
Mendoza a little and very fat negress, riding astride on a mule. She
had a _goître_ so enormous, that it was scarcely possible to avoid
gazing at her for a moment; but my two companions almost instantly,
by way of apology, made the common salute of the country, by taking
off their hats. Where would one of the lower classes in Europe have
shown such feeling politeness to a poor and miserable object of a
degraded race?
At night we slept at a cottage. Our manner of travelling was
delightfully independent. In the inhabited parts we bought a little
firewood, hired pasture for the animals, and bivouacked in the
corner of the same field with them. Carrying an iron pot, we cooked
and ate our supper under the cloudless sky, and knew no trouble. My
companions were Mariano Gonzales, who had formerly accompanied me,
and an “arriero,” with his ten mules and a “madrina.”
The madrina (or godmother) is a most important personage. She is an
old steady mare, with a little bell round her neck; and wheresoever
she goes, the mules, like good children, follow her. If several
large troops are turned into one field to graze, in the morning the
muleteer has only to lead the madrinas a little apart, and tinkle
their bells; and, although there may be two or three hundred mules
together, each immediately knows its own bell, and separates itself
from the rest. The affection of these animals for their madrinas
saves infinite trouble. It is nearly impossible to lose an old
mule; for if detained for several hours by force, she will, by the
power of smell, like a dog, track out her companions, or rather the
madrina; for, according to the muleteer, she is the chief object of
affection. The feeling, however, is not of an individual nature; for
I believe I am right in saying, that any animal with a bell will
serve as madrina. In a troop each animal carries, on a level road,
a cargo weighing 416 pounds (more than twenty-nine stone); but in a
mountainous country a hundred pounds less.[1] Yet with what delicate
slim limbs, without any proportional bulk of muscle, these animals
support so great a burden! The mule always appears to me a most
surprising animal. That a hybrid should possess more reason, memory,
obstinacy, social affection, and powers of muscular endurance,
than either of its parents, seems to indicate that art has here
out-mastered nature. Of our ten animals, six were intended for riding
and four for carrying cargoes, each taking turn about. We carried a
good deal of food, in case we should be snowed up, as the season was
rather late for passing the Portillo.
MARCH 19TH.--We rode during this day to the last, and therefore
most elevated house in the valley. The number of inhabitants became
scanty; but wherever water could be brought on the land, it was very
fertile. All the valleys in the Cordillera agree in the same kind of
structure. An irregularly-stratified mass of well-rounded shingle,
together with a little mud and sand, fills up the bottom to the
depth of some hundred feet. This deposit follows the course of the
valley, sloping upwards with a most gradual and gentle inclination.
The rivers have removed a large part in the centre; thus leaving a
terrace of equal height, but varying width, on each side. This narrow
space between the cliffs bordering the bed of the river, and the foot
of the mountains, is the only part fit for cultivation, and on it
likewise the road is carried.
The rivers, such as the Maypo, which flow in these valleys, should
rather be called mountain torrents. Their inclination is very great,
and their water the colour of mud. The roar which the Maypo made,
as it rushed over the great rounded fragments, was like that of the
sea. Amidst the din of rushing waters, the noise from the stones, as
they rattled one over another, was most distinctly audible even at
a distance. This rattling noise, night and day, may be heard along
the whole course of the torrent. The sound spoke eloquently to the
geologist: the thousands and thousands of stones, which, striking
against each other, make the one dull uniform sound, are all hurrying
in one direction. It is like thinking of time, where the minute that
now glides past is irrecoverable. So is it with these stones; the
ocean is their eternity, and each note of that wild music tells of
one other step towards their destiny.
It is not possible for the mind to comprehend, except by a slow
process, any effect which is produced by a cause repeated so often,
that the multiplier itself ceases to convey any more definite idea,
than the savage receives when he points to the hairs of his head. As
often as I have seen beds of mud, sand, and shingle, accumulated to
the thickness of many thousand feet, I have felt inclined to exclaim
that causes, such as the present rivers and the present beaches,
could never have ground down such masses. But, on the other hand,
when listening to the rattling noise of these torrents, and calling
to mind that whole races of animals have passed away from the surface
of the globe, during the period throughout which, night and day,
these stones have gone rattling onwards in their course, I have
thought to myself, can any mountains, any continent, withstand such
waste?
In this part of the valley, the mountains on each side are from about
three to six or eight thousand feet high: their outline is rounded,
but with steep and bare flanks. The general colour of the rock is a
dullish purple, and the stratification very distinct. If the scenery
is not beautiful, it is remarkable and grand. We met during the
day several herds of cattle, which men were driving down from the
higher valleys in the Cordillera. This sign of the approaching winter
hurried our steps, more than was convenient for geological purposes.
The house where we slept was situated at the foot of a mountain, on
the summit of which are the mines of S. Pedro de Nolasko.
Sir F. Head wonders how mines have been discovered in situations
so extraordinary, as the bleak summit of the mountain of S. Pedro
de Nolasko. In the first place, metallic veins in this country are
generally harder than the surrounding strata: hence, during the
gradual degradation of the hills, they project above the surface
of the ground. Secondly, almost every labourer, especially in the
northern parts of Chile, understands something about the appearance
of ores. In the great mining provinces of Coquimbo and Copiapó,
firewood is very scarce, and men are employed in searching for it
over every hill and dale; and by this means nearly all the richest
mines have there been discovered. Chanuncillo, from which silver,
to the value of many hundred thousand pounds has been raised in the
course of a few years, was thus discovered: a man having thrown a
stone at his loaded donkey, afterwards thought that it was very
heavy, and picking it up again, he found it was full of pure silver.
The vein occurred at no great distance, standing up like a wedge of
silver. The miners also, on Sundays, taking a crowbar with them,
often set out on such discoveries. In the south part of Chile, the
men who drive cattle into the Cordillera, and who frequent every
ravine where there is a little pasture, are the usual agents.
MARCH 20TH.--As we ascended the valley, the vegetation, with the
exception of a few pretty alpine flowers, became exceedingly scanty;
and of birds, animals, or insects, scarcely one could be seen. The
lofty mountains, their summits marked with a few patches of snow,
stood well separated from each other; the valleys being filled
up with an immense thickness of stratified alluvium. I may here
briefly remark, without detailing the reasons on which the opinion
is grounded, that in all probability this matter was accumulated at
the bottoms of deep arms of the sea, which running from the inland
basins, penetrated to the axis of the Cordillera,--in a similar
manner to what now happens in the southern part of this same great
range. This fact, in itself most curious, as preserving a record of a
very ancient state of things, possesses a high theoretical interest,
when considered in relation to the kind of elevation by which the
present great altitude of these mountains has been attained.
The features in the scenery of the Andes which struck me most,
as contrasted with the few other mountain chains with which I am
acquainted, were,--the flat fringes sometimes expanding into narrow
plains on each side the valleys,--the bright colours, chiefly red
and purple, of the utterly bare and precipitous hills,--the grand
and continuous wall-like dikes,--the strongly-marked strata which,
when nearly vertical, form the most picturesque and wild pinnacles,
but where less inclined, great massive mountains; the latter
occupying the outskirts of the range, and the former the more lofty
and central parts,--lastly, the smooth conical piles of fine and
brightly-coloured detritus, which slope at a high angle from the
flanks of the mountains to their bases, some of the piles having a
height of more than two thousand feet.
I frequently observed both in Tierra del Fuego, and within the
Andes, that where the rock was covered during the greater part of
the year with snow, it was shivered in a very extraordinary manner
into small angular fragments. Scoresby[2] has observed the same fact
in Spitzbergen: he says, “The invariably broken state of the rocks
appeared to have been the effect of frost. On calcareous rocks, some
of which are not impervious to moisture, the effect is such as might
have been expected; but how frost can operate in this way on quartz
is not so easily understood.” The whole phenomenon appears to me
rather obscure: for that part of the mountain which is covered during
many months by a mantle of snow, must be less subject to repeated
and great changes of temperature than any other, yet it is the most
affected. I have sometimes thought, that the earth and fragments of
stone lying on the surface, were perhaps less effectually removed
by means of slowly percolating snow-water,[3] than by the agency of
rain, and therefore that the appearance of a quicker decay of the
solid rock may be deceptive. Whatever the cause may be, the quantity
of crumbling stone on the Cordillera is very great. Occasionally in
the spring, masses of such matter slide down the mountains, and cover
the snow-drifts in the valleys; thus forming natural ice-houses. We
rode over one, the elevation of which was far below the limit of
perpetual congelation.
As the evening drew to a close, we reached the Valle del Yeso. This
is a very singular basin, which must have once been a very deep and
large lake: the barrier is formed by a huge mountain of alluvium, on
one side of which the river has cut a gorge. The plain is covered
by a little dry pasture, and amidst the surrounding rocky deserts
we had the pleasant sight of a herd of cattle. The valley takes its
name of Yeso from a great bed, I should think at least two thousand
feet thick, of white, and in some parts quite pure, gypsum. We slept
with a party of men, who were employed in loading mules with this
substance, which is used in the manufacture of wine.
MARCH 21ST.--We set out early in the morning, and continued to follow
the course of the river, which by this time had become small, till we
arrived at the foot of the ridge that separates the waters flowing
into the Pacific and Atlantic oceans. The road, which as yet had been
good, with a steady but very gradual ascent, now changed into a steep
zigzag track. The Cordillera in this part consists of two principal
ranges; the passes across which attain respectively an elevation
of 13,210 and 14,365 feet.[4] The first great line (consisting of
course of many subordinate ones) is called Peuquenes. It divides the
waters, and therefore likewise the republics of Chile and Mendoza.
To the eastward, a mountainous and elevated region separates it from
the second range (called the Portillo) overlooking the Pampas. The
streams from the intermediate tract find a passage a little way to
the southward through this second line.
I will here give a very brief sketch of the geological structure
of these mountains: first, of the Peuquenes, or western line; for
the constitution of the two ranges is totally different. The lowest
stratified rock is a dull red or purple claystone porphyry, of many
varieties, alternating with conglomerates, and breccia composed of a
similar substance: this formation attains a thickness of more than
a mile. Above it there is a grand mass of gypsum, which alternates,
passes into, and is replaced by, red sandstone, conglomerates, and
black calcareous clay-slate. I hardly dare venture to guess the
thickness of this second division; but I have already said some of
the beds of gypsum alone attain a thickness of at least two thousand
feet. Even at the very crest of the Peuquenes, at the height of
13,210 feet, and above it, the black clay-slate contained numerous
marine remains, amongst which a gryphæa is the most abundant,
likewise shells, resembling turritellæ, terebratulæ, and an ammonite.
It is an old story, but not the less wonderful, to hear of shells,
which formerly were crawling about at the bottom of the sea,
being now elevated nearly fourteen thousand feet above its level.
The formation probably is of the age of the central parts of the
secondary series of Europe.
These great piles of strata have been penetrated, upheaved, and
overturned, in the most extraordinary manner, by masses of injected
rock, equalling mountains in size. On the bare sides of the hills,
complicated dikes, and wedges of variously-coloured porphyries and
other stones, are seen traversing the strata in every possible form
and direction; proving also by their intersections, successive
periods of violence. The rock which composes the axis of these great
lines of dislocation, at a distance very closely resembles granite,
but on examination, it is found rarely to contain any quartz; and
instead of ordinary felspar, albite.
The metamorphic action has been very great, as might have been
expected from the close proximity of such grand masses of rock,
which were injected when in a liquefied state from heat. When it
is known, first, that the stratified porphyries have flowed as
streams of submarine lava under an enormous pressure, and that the
mechanical beds separating them owe their origin to explosions
from the same submarine craters; secondly, that the whole mass in
the lower part has generally been so completely fused into one
solid rock by metamorphic action, that the lines of division can
only be traced with much difficulty; and thirdly, that masses of
porphyry, undistinguishable by their mineralogical characters from
the two first kinds, have been subsequently injected;--the extreme
complication of the whole will readily be believed.
We now come to the second range, which is of even greater
altitude than the first. Its nucleus in the section seen in
crossing the Portillo pass, consists of magnificent pinnacles of
coarsely-crystallized red granite. On the eastern flank, a few
patches of mica slate still adhere to the unstratified mass; and at
the foot a stream of basaltic lava has burst forth at some remote
period,--perhaps when the sea covered the wide surface of the Pampas.
On the western side of the axis, between the two ranges, laminated
fine sandstone has been penetrated by immense granitic dikes
proceeding from the central mass, and has thus been converted into
granular quartz rock. The sandstone is covered by other sedimentary
deposits, and these again by a coarse conglomerate, the vast
thickness of which I will not attempt even to estimate. All these
coarse mechanical beds dip from the red granite directly towards the
Peuquenes range, as if they passed beneath it; though such is not the
case. On examining the pebbles composing this conglomerate (which,
to my surprise, betrayed no signs of metamorphic action), I was
astonished to find perfectly rounded masses of the black calcareous
clay-slate with organic remains,--the same rock which I had just
crossed _in situ_ on the Peuquenes. These phenomena compel us to
arrive at the following conclusion:--that the Peuquenes existed as
dry land for a long period anterior to the formation of the second
range, and that, during this period, immense quantities of shingle
were accumulated at its submarine flank. The action of a disturbing
force then commenced: these more modern deposits were injected by
dikes, altered by heat, and tilted towards the line whence, in the
form of sediment and pebbles, they had originally proceeded,--thus
making the offspring at first appear older than its parent. This
second, grand, and subsequent line of elevation is parallel to the
first and more ancient one.
I will only make one other geological observation: the Portillo chain
in the neighbourhood of the pass is rather more elevated than the
Peuquenes, yet the waters of the intermediate district have burst a
passage through it. On the supposition of a subsequent and gradual
elevation of the second line, this can be understood; for a chain
of islets would at first appear, and as these were lifted up, the
tides would always be working out deeper and broader channels between
them. At the present day, even in the most retired sounds on the
southern coast, the currents in the transverse breaks which connect
the longitudinal channels, is so strong, that I have heard of one
instance where a small vessel under sail was whirled round and round.
Mr. Pentland,[5] when describing an hydrographical phenomenon of
a nearly similar kind, but on an infinitely grander scale, which
occurs in Bolivia, says, “This very curious fact, of rivers escaping
through such an immense mountain-mass as the Bolivian Cordillera, is
perhaps one of the most important points connected with the physical
geography of this portion of the Andes, and deserves to be noticed
at greater length.” It would be extremely rash to affirm that the
eastern chain in Bolivia, like that of central Chile, must be of
subsequent origin to the western one, or that nearer to the Pacific:
but excepting through the explanation above offered, the circumstance
that rivers flowing from a less elevated chain, should penetrate one
far more lofty, appears to me quite inexplicable.
About noon we began the tedious ascent of the Peuquenes, and then
for the first time experienced some little difficulty in our
respiration. The mules would halt every fifty yards, and then the
poor willing animals after a few seconds started of their own accord
again. The short breathing from the rarefied atmosphere is called by
the Chilenos “puna;” they have most ridiculous notions concerning
its origin. Some say, “all the waters here have puna;” others that
“where there is snow there is puna;”--and this no doubt is true. It
is considered a kind of disease, and I was shown the crosses over
the graves of some who had died “punado.” Excepting perhaps in the
case of a person suffering from some organic disease of the heart
or chest, I should think this must be an erroneous conclusion. A
person near death, would probably at this elevation experience a more
unusual difficulty in breathing than others; and hence the effect
might be assumed as the cause. The only sensation I felt was a slight
tightness over the head and chest; a feeling which may be experienced
by leaving a warm room and running violently on a frosty day. There
was much fancy even in this; for upon finding fossil shells on the
highest ridge, I entirely forgot the puna in my delight. Certainly
the exertion of walking was extreme, and the respiration became deep
and laborious. It is incomprehensible to me, how Humboldt and others
were able to ascend to the elevation of 19,000 feet. No doubt a
residence of some months in the lofty region of Quito would prepare
the constitution for such an exertion; yet I am told that in Potosi
(about 13,000 feet), strangers do not become quite accustomed to the
atmosphere for an entire year. The inhabitants all recommend onions
for the puna; as this vegetable has sometimes been given in Europe
for pectoral complaints, it may possibly be of real service:--for my
part, I found nothing so good as the fossil shells!
When about halfway up we met a large party with seventy loaded mules.
It was interesting to hear the wild cries of the muleteers, and
to watch the long string descending; they appeared so diminutive,
there being nothing but the bleak mountains with which they could be
compared. When near the summit, the wind, as generally happens there,
was impetuous and extremely cold. On each side of the ridge we had to
pass over broad bands of snow, which perpetually lie there, and were
now soon to be covered by a fresh layer. When we reached the crest
and looked backwards, a glorious view was presented. The atmosphere
resplendently clear; the sky an intense blue; the profound valleys;
the wild broken forms; the heaps of ruins, piled up during the
lapse of ages; the bright-coloured rocks, contrasted with the quiet
mountains of snow; all these together produced a scene I never could
have figured to my imagination. Neither plant nor bird, excepting
a few condors wheeling around the higher pinnacles, distracted the
attention from the inanimate mass. I felt glad I was alone: it was
like watching a thunderstorm, or hearing a chorus of the Messiah in
full orchestra.
On several of the patches of perpetual snow, I found the _Protococcus
nivalis_, or red snow, so well known from the accounts of Arctic
navigators. My attention was called to the circumstance by observing
the footsteps of the mules stained a pale red, as if their hoofs
had been slightly bloody. I at first thought it was owing to
dust blown from the surrounding mountains of red porphyry; for
from the magnifying power of the crystals of snow, the groups
of these atom-like plants appeared like coarse particles. The
snow was coloured only where it had thawed very rapidly, or had
been accidentally crushed. A small portion of it rubbed on paper
communicated a faint rose tinge, mingled with a little brick red. I
placed some of the snow between the leaves of my pocket-book, and
a month afterwards examined with care the pale discoloured patches
on the paper. The specimens, when scraped off, were of a spherical
form, with a diameter of the thousandth of an inch. The central part
consists of a blood-red substance, surrounded by a colourless bark.
When living on the snow they are collected in groups, many lying
close together; I overlooked, however, the thin couch of gelatinous
matter on which they are said to rest.[6] The dried specimens placed
in any fluid, as water, spirits of wine, or dilated sulphuric acid,
were acted on in two different ways: sometimes an expansion was
caused, at others a contraction. The central part after immersion
invariably appeared as a drop of red oily fluid, containing a few
most minute granules; and these probably are the germs of new
individuals.
As I before remarked, the wind on the crest of the Peuquenes is
generally impetuous and very cold. It is said to blow steadily from
the westward or Pacific side: a circumstance which is likewise
mentioned by Dr. Gillies.[7] As these observations apply chiefly to
the summer season (when the passes are frequented), we must consider
this wind, as an upper and return current. The Peak of Teneriffe,
with a less elevation, and situated in lat. 28°, in like manner falls
within the return stream. At first it appears rather surprising, that
the trade-wind along the northern parts of Chile, and on the coast
of Peru, should blow in so very southerly a direction as it does;
but when we reflect, that the Cordillera, running in a north and
south line, intercepts, like a great wall, the entire depth of the
lower atmospheric current, we can easily see, that the trade-wind
must be drawn northward, following the line of mountains, towards
the equatorial regions, and thus lose part of that easterly movement
which it otherwise would have gained from the rotation of the world.
At Mendoza, on the eastern foot of the Andes, the climate is said to
be subject to long calms, and to frequent though false appearances
of gathering rain-storms: we may imagine that the wind, which coming
from the eastward is thus banked up by the line of mountains, would
become stagnant and irregular in its movements.
Having crossed the Peuquenes, we descended into the mountainous
country, intermediate between the two ranges, and then took up our
quarters for the night. The elevation was probably not much under
11,000 feet, and the vegetation in consequence exceedingly scanty.
The root of a small scrubby plant served as fuel, but it made a
miserable fire, and the wind was piercingly cold. Being quite tired
with my day’s work, I made up my bed as quickly as I could, and went
to sleep. About midnight I observed the sky became suddenly clouded:
I awakened the arriero to know if there was any danger of bad
weather; but he said that without thunder and lightning there was no
risk of a heavy snow-storm. The peril is imminent, and the difficulty
of subsequent escape great, to any one overtaken by bad weather
between the two Cordillera. A certain cave offers the only place of
refuge: Mr. Caldcleugh, who crossed on this same day of the month,
was detained there for some time by a heavy fall of snow, as is
related in his travels. Casuchas, or houses of refuge, have not been
built in this pass as in that of Uspallata, and therefore, during the
autumn, the Portillo is little frequented. I may here remark, that
within the main Cordillera rain never falls, for during the summer,
the sky is cloudless, and in winter snow-storms alone occur.
At the place where we slept, water necessarily boiled, from the
diminished pressure of the atmosphere, at a much lower temperature
than it does in a less elevated country; the case being the converse
of that of a Papin’s digester. In consequence of this, the potatoes,
after remaining for some hours in the boiling water, were nearly
as hard as ever. The pot was left on the fire all night, and next
morning it was boiled again, but yet the potatoes were not cooked.
I found out this, by overhearing my two companions discussing the
cause; they had come to the simple conclusion, “that the cursed pot
(which was a new one) did not choose to boil potatoes.”
MARCH 22D.--After eating our potato-less breakfast, we travelled
across the intermediate tract, to the foot of the Portillo range. In
the middle of summer cattle are brought up here to graze; but they
had now all been removed; even the greater number of the guanacoes
had decamped, knowing well, that, if overtaken by a snow-storm, they
would be caught in a trap. We had a fine view of a mass of mountains
called Tupungato, the whole clothed with unbroken snow. From one peak
my arriero said he had once seen smoke proceeding; and I thought I
could distinguish the form of a large crater. In the maps Tupungato
figures as a single mountain; this Chileno method of giving one name
to a tract of mountains is a fruitful source of error. In the region
of snow there was a blue patch, which no doubt was a glacier;--a
phenomenon that has been said not to occur in these mountains.
Now commenced a heavy and long climb, similar to that up the
Peuquenes. Bold conical hills of red granite rose on each hand; and
in the valley there were several broad fields of perpetual snow.
These frozen masses, during the process of thawing, had in some
parts assumed the form of pinnacles or columns, which, as they were
high and close together, caused some difficulty on account of the
cargo mules. This structure in frozen snow was long since observed
by Scoresby in the icebergs near Spitzbergen, and lately, with more
care, by Colonel Jackson[8] on the Neva. On one of these columns
of ice a frozen horse was exposed, sticking as on a pedestal, but
with its hind legs straight up in the air. To account for its
strange position, we must suppose that the animal fell with its
head downward into a hole, when the stratum was continuous, and that
afterwards the surrounding parts were removed by the thaw.
When nearly on the crest of the Portillo, we were enveloped in a
cloud which was falling, under the form of minute frozen spicula.
This was very unfortunate, as it continued the whole day, and quite
intercepted our view. The pass takes its name of Portillo from a
narrow cleft or doorway on the highest ridge, through which the road
passes. From this point, on a clear day, those vast plains which
extend from the base of the mountains towards the Atlantic can be
seen. We descended to the upper limit of vegetation, and found good
quarters for the night under the shelter of some large fragments of
rock. We here met some passengers, who made anxious inquiries about
the state of the road. Shortly after it was dark, the clouds suddenly
cleared away; and the effect was quite magical. The great mountains,
bright with the full moon, seemed impending over us on all sides, as
if we had been buried at the bottom of some deep crevice. One morning
also, very early, I witnessed the same striking effect. As soon as
the clouds were dispersed, it froze severely; but as there was no
wind, we slept very comfortably.
The increased brilliancy of the moon and stars at this elevation,
owing to the perfect transparency of the atmosphere, was very
remarkable. Travellers having observed the difficulty of judging
heights and distances amidst lofty mountains, have generally
attributed it to the absence of objects of comparison. It appears to
me that it is fully as much owing to this transparency, confounding
different distances, and partly, likewise, to the novelty of an
unusual degree of fatigue arising from a little exertion,--habit
being thus opposed to the evidence of the senses. I am sure that
this extreme clearness of the air gives a peculiar character to the
landscape; all objects appearing to be brought nearly into one plane,
as in a drawing or panorama. The transparency is, I presume, owing
to the equable and nearly perfect state of atmospheric dryness. The
latter quality was shown by the manner in which woodwork shrunk (as I
soon found by the trouble my geological hammer gave me); by articles
of food, such as bread and sugar, becoming extremely hard; and by the
preservation of the skin and parts of the flesh of the beasts, which
perish on the road. To the same cause we must attribute the singular
facility with which electricity is excited. My flannel-waistcoat,
when rubbed in the dark, appeared as if it had been washed with
phosphorus;--every hair on a dog’s back crackled;--even the linen
sheets, and leathern straps of the saddle, when handled, emitted
sparks.
MARCH 23D.--The descent on the eastern side of the Cordillera is
much shorter or steeper than on the Pacific side; in other words,
the mountains rise more abruptly from the plains, than from the
alpine country of Chile. A level and brilliantly white sea of clouds
was extended beneath our feet, and thus shut out the view of the
equally level Pampas. We soon entered the band of clouds, and did not
again emerge from it that day. About noon, finding pasture for the
animals and bushes for firewood, in a part of the valley called Los
Arenales, we stopped for the night. This was near the uppermost limit
of bushes, and the elevation, I suppose, was between seven and eight
thousand feet.
I was very much struck with the marked difference between the
vegetation of these eastern valleys and that of the opposite side:
yet the climate, as well as the kind of soil, is nearly identical,
and the difference of longitude very trifling. The same remark holds
good with the quadrupeds, and in a lesser degree with the birds
and insects. We must except certain species which habitually or
occasionally frequent elevated mountains; and in the case of the
birds, certain kinds, which have a range as far south as the Strait
of Magellan. This fact is in perfect accordance with the geological
history of the Andes; for these mountains have existed as a great
barrier, since a period so remote that whole races of animals must
subsequently have perished from the face of the earth. Therefore,
unless we suppose the same species to have been created in two
different countries, we ought not to expect any closer similarity
between the organic beings on opposite sides of the Andes, than on
shores separated by a broad strait of the sea. In both cases we must
leave out of the question those kinds which have been able to cross
the barrier, whether of salt water or solid rock.[9]
A great number of the plants and animals were absolutely the same, or
most closely allied with those of Patagonia. We here have the agouti,
bizcacha, three species of armadillo, the ostrich, certain kinds of
partridges, and other birds, none of which are ever seen in Chile,
but are the characteristic animals of the desert plains of Patagonia.
We have likewise many of the same (to the eyes of a person who is not
a botanist) thorny stunted bushes, withered grass, and dwarf plants.
Even the black slowly-crawling beetles are closely similar, and
some, I believe, on rigorous examination, absolutely identical. It
had always been a subject of regret to me, that we were unavoidably
compelled to give up the ascent of the St. Cruz river before reaching
the mountains. I always had a latent hope of meeting with some great
change in the features of the country; but I now feel sure, that it
would only have been following the plains of Patagonia up an ascent.
MARCH 24TH.--Early in the morning I climbed up a mountain on one side
of the valley, and enjoyed a far-extended view over the Pampas. This
was a spectacle to which I had always looked forward with interest,
but I was disappointed. At the first glance there was a strong
resemblance to a distant view of the ocean, but in the northern parts
many irregularities in the surface were soon distinguishable. The
most striking feature in the scene consisted of the rivers, which,
facing the rising sun, glittered like silver threads, till lost in
the immensity of the distance.
In the middle of the day, we descended the valley, and reached a
hovel, where an officer and three soldiers were posted to examine
passports. One of these men was a thorough-bred Pampas Indian. He
was kept much for the same purpose as a bloodhound, to track out any
person who might pass by secretly, either on foot or horseback. Some
years ago, a passenger had endeavoured to escape detection, by making
a long circuit over a neighbouring mountain; but this Indian, having
by chance crossed his track, followed it for the whole day, over dry
and very stony parts, till at last he came on his prey hidden in a
gully. We here heard that the silvery clouds, which we had admired
from the bright region above, had poured down torrents of rain.
The valley from this point gradually opened, and the hills became
mere water-worn hillocks compared to the giants behind. It then
expanded into a gently-sloping plain of shingle, covered with low
trees and bushes. This talus, although it looked of little breadth,
must be nearly ten miles wide, before it blends into the apparently
dead level Pampas. We had already passed the only house in this
neighbourhood, the Estancia of Chaquaio; and at sunset we pulled up
in the first snug corner, and there bivouacked.
MARCH 25TH.--I was reminded of the Pampas of Buenos Ayres, by seeing
the disk of the rising sun, intersected by an horizon, level as
that of the ocean. During the night a heavy dew had fallen, a fact
we did not experience within the Cordillera. The road proceeded
for some distance due east across a low swamp; then meeting the
dry plain, it turned to the north towards Mendoza. The distance is
two very long days’ journey. Our first day’s journey was called
fourteen leagues to Estacado, and the second seventeen to Luxan,
near Mendoza. The whole distance is over a level desert plain, with
not more than two or three houses. The sun was exceedingly powerful,
and the ride devoid of all interest. There is very little water in
this “traversia,” and in our second day’s journey, we found only
one little pool. The water flowing from the mountains is small in
quantity and soon becomes absorbed by the dry and porous soil; so
that, although we travelled at the distance of only ten or fifteen
miles from the outer range, we did not cross a single stream. In many
parts the ground was incrusted with a saline efflorescence; hence
we had the same salt-loving plants, common near Bahia Blanca. The
landscape has one character from the Strait of Magellan along the
whole eastern coast of Patagonia to the Rio Colorado; and it appears
that the same kind of country extends northerly in a sweeping line as
far as San Luis, and perhaps even further. To the eastward of this
line, lies the basin of the comparatively damp and green plains of
Buenos Ayres. The former country, including the sterile traversia of
Mendoza and Patagonia, consists of a bed of shingle, worn smooth, and
accumulated by the waves of a former sea; while the formation of the
Pampas (plains covered by thistles, clover, and grass) is due to the
estuary mud of the Plata, deposited under a different condition of
circumstances.
After our two days’ tedious journey, it was refreshing to see in the
distance the rows of poplars and willows growing around the village
and river of Luxan. Shortly before we arrived at this place, we
observed to the southward a ragged cloud of a dark reddish-brown
colour. For some time, we had no doubt but that it was thick smoke
proceeding from some great fire on the plains. Soon afterwards we
found it was a pest of locusts.[10] The insects overtook us, as they
were travelling northward, by the aid of a light breeze, at the rate,
I should suppose, of ten or fifteen miles an hour. The main body
filled the air from a height of twenty feet, to that, as it appeared,
of two or three thousand above the ground. The noise of their
approach was that of a strong breeze[11] passing through the rigging
of a ship. The sky seen through the advanced guard appeared like a
mezzotinto engraving, but the main body was impervious to sight;
they were not, however, so thick, but that they could escape from a
stick moved backward and forward. When they alighted they were more
numerous than the leaves in a field, and changed the green into a
reddish colour: the swarm having once alighted, the individuals flew
from side to side in any direction. The locusts are not an uncommon
pest in this country: already during the season, several smaller
swarms had come up from the sterile plains[12] of the south; and many
trees had been entirely stripped of their leaves. Of course this
swarm cannot even be compared to those of the eastern world, yet it
was sufficient to make the well-known descriptions of their ravages
more intelligible. I have omitted, perhaps, the most striking part
of the scene,--the vain attempts of the poor cottagers to turn the
stream aside. Many lighted fires and with the smoke, with shouts and
waving of branches, they endeavoured to avert the attack.
We crossed the Luxan, which is a river of considerable size, though
its course towards the sea-coast is very imperfectly known. It is
even doubtful whether, in passing over the plains, it is evaporated,
or whether it forms a tributary of the Sauce or Colorado. We slept
in the village, which is a small place surrounded by gardens, and
forms the most southern part, that is cultivated, of the province
of Mendoza; it is five leagues south of the capital. At night I
experienced an attack (for it deserves no less a name) of the
_Benchuca_ (a species of Reduvius) the great black bug of the Pampas.
It is most disgusting to feel soft wingless insects, about an inch
long, crawling over one’s body. Before sucking they are quite thin,
but afterwards become round and bloated with blood, and in this
state they are easily crushed. They are also found in the northern
parts of Chile and in Peru. One which I caught at Iquique was very
empty. When placed on the table, and though surrounded by people, if
a finger was presented, the bold insect would immediately draw its
sucker, make a charge, and if allowed, draw blood. No pain was caused
by the wound. It was curious to watch its body during the act of
sucking, as it changed in less than ten minutes, from being as flat
as a wafer to a globular form. This one feast, for which the benchuca
was indebted to one of the officers, kept it fat during four whole
months; but, after the first fortnight, the insect was quite ready to
have another suck.
MARCH 27TH.--We rode on to Mendoza. The country was beautifully
cultivated, and resembled Chile. This neighbourhood is celebrated
for its fruit; and certainly nothing could appear more flourishing
than the vineyards and the orchards of figs, peaches, and olives.
We bought watermelons nearly twice as large as a man’s head, most
deliciously cool and well-flavoured, for a halfpenny apiece; and
for the value of threepence, half a wheelbarrowful of peaches. The
cultivated and enclosed part of this province is very small; there
is little more than that which we passed through between Luxan and
the capital. The land, as in Chile, entirely owes its fertility to
artificial irrigation; and it is really wonderful to observe how
abundantly productive a barren traversia is rendered by this simple
process.
We staid the ensuing day in Mendoza. The prosperity of the place
has much declined of late years. The inhabitants say “it is good to
live in, but very bad to grow rich in.” The lower orders have the
lounging, reckless manners of the Gauchos of the Pampas; and their
dress, riding gear, and habits of life, are nearly the same. To
my mind the town had a stupid forlorn aspect. Neither the boasted
alameda, nor the scenery, is at all comparable to that of Santiago;
but to those who have just crossed the unvaried savannahs of grass,
on their road from Buenos Ayres, the gardens and orchards must appear
delightful. Captain Head, speaking of the inhabitants, says, “They
eat their dinners, and it is so very hot, they go to sleep--and could
they do better?” I quite agree with Captain Head: the happy doom of
the Mendozinos is to eat, sleep, and be idle.
MARCH 29TH.--We set out on our return to Chile by the Uspallata pass
to the northward of Mendoza. We had to cross a long and most sterile
traversia of fifteen leagues. The soil in parts was absolutely bare,
in others covered by numberless dwarf cacti, armed with formidable
spines, and called by the inhabitants “little lions.” There were
also a few low bushes. Although the plain is elevated about three
thousand feet above the sea, the sun was very powerful; this, and the
clouds of impalpable dust, rendered the travelling extremely irksome.
Our course during the day lay nearly parallel to the mountains, but
gradually approaching them. Before sunset we entered one of the wide
valleys, or rather bays, which open on the plain: this soon narrowed
into a ravine, and a little higher up the house of the Villa Vicencio
was situated. As we had ridden all day without a drop of water,
both ourselves and our animals were very thirsty, and we looked out
anxiously for the stream which flows down this valley. It was curious
to observe how gradually the water made its appearance: on the plain
the course was quite dry; by degrees it became a little damper; then
puddles of water were formed; these soon became connected, and at
Villa Vicencio there was a nice little rivulet.
30TH.--The solitary hovel which bears the imposing name of Villa
Vicencio, has been mentioned by every traveller who has crossed the
Andes. I staid here, and at some neighbouring mines, during the two
succeeding days. The geology of the surrounding country is very
curious. The Uspallata range is separated from the true Cordillera by
a long narrow plain or basin, like those so often mentioned in Chile,
but with an altitude of about six thousand feet. The range consists
of various kinds of submarine lava, alternating with volcanic
sandstones and other remarkable sedimentary deposits; the whole
having a very close resemblance to some of the newer horizontal
beds on the shores of the Pacific. From this resemblance I expected
to find silicified wood, which is generally characteristic of those
formations. I was gratified in a very extraordinary manner. In the
central part of the range, at an elevation probably of seven thousand
feet, on a bare slope, I observed some snow-white projecting columns.
These were petrified trees, eleven being silicified, and from thirty
to forty converted into coarsely-crystallized white calcareous spar.
They were abruptly broken off; the upright stumps projecting a few
feet above the ground. The trunks measured from three to five feet
each in circumference. They stood a little way apart from each other,
but the whole formed one distinct group. Mr. Robert Brown has been
kind enough to examine the wood: he says it is coniferous, and that
it partakes of the character of the Araucarian tribe (to which the
common South Chilian pine belongs), but with some curious points of
affinity with the yew. The volcanic sandstone in which they were
embedded, and from the lower part of which they must have sprung, had
accumulated in successive thin layers around their trunks; and the
stone yet retained the impression of the bark.
It required little geological practice to interpret the marvellous
story, which this scene at once unfolded; though I confess I was at
first so much astonished that I could scarcely believe the plainest
evidence of it. I saw the spot where a cluster of fine trees had once
waved their branches on the shores of the Atlantic, when that ocean
(now driven back 700 miles) approached the base of the Andes. I saw
that they had sprung from a volcanic soil which had been raised above
the level of the sea, and that this dry land, with its upright trees,
had subsequently been let down to the depths of the ocean. There it
was covered by sedimentary matter, and this again by enormous streams
of submarine lava--one such mass alone attaining the thickness of a
thousand feet; and these deluges of melted stone and aqueous deposits
had been five times spread out alternately. The ocean which received
such masses must have been deep; but again the subterranean forces
exerted their power, and I now beheld the bed of that sea forming a
chain of mountains more than seven thousand feet in altitude. Nor
had those antagonist forces been dormant, which are always at work
to wear down the surface of the land to one level: the great piles
of strata had been intersected by many wide valleys; and the trees
now changed into silex were exposed projecting from the volcanic soil
now changed into rock, whence formerly in a green and budding state
they had raised their lofty heads. Now, all is utterly irreclaimable
and desert; even the lichen cannot adhere to the stony casts of
former trees. Vast, and scarcely comprehensible as such changes must
ever appear, yet they have all occurred within a period recent when
compared with the history of the Cordillera; and that Cordillera
itself is modern as compared with some other of the fossiliferous
strata of South America.
APRIL 1ST.--We crossed the Uspallata range; and at night slept at the
custom-house--the only inhabited spot on the plain. Shortly before
leaving the mountains, there was a very extraordinary view: red,
purple, green, and quite white sedimentary rocks, alternating with
black lavas, were broken up and thrown into all kinds of disorder, by
masses of porphyry, of every shade, from dark brown to the brightest
lilac. It was the first view I ever saw, which really resembled those
pretty sections which geologists make of the inside of the earth.
The next day we crossed the plain, and followed the course of the
same great mountain-stream which flows by Luxan. Here it was a
furious torrent, quite impassable, and appearing larger than in the
low country; as was the case with the rivulet of Villa Vincencio. On
the evening of the succeeding day we reached the Rio de las Vacas,
which is considered the worst stream in the Cordillera to cross.
As all these rivers have a rapid and short course, and are due to
the snow melted by the sun’s heat, the hour of the day makes a
considerable difference in their volume. In the evening the stream is
muddy and full, but about daybreak it becomes both clearer and much
less impetuous. This we found to be the case with the Rio Vacas, and
in the morning we crossed it with little difficulty.
The scenery thus far was very uninteresting, compared with that of
the Portillo pass. Little can be seen beyond the bare walls of the
one grand, flat-bottomed valley, which the road follows up to the
highest crest. The valley and the huge rocky mountains were extremely
barren: during the two previous nights the poor mules had absolutely
nothing to eat; for excepting a few low resinous bushes, scarcely
a plant could be seen. We went over in the course of this day some
of the worst passes in the Cordillera. The degree of exaggeration
concerning their danger and difficulty is very great. In Chile I
was even told, that if I attempted to pass on foot my head would
turn giddy, that there was no room to dismount, &c., but I did not
see a place where any one might not have walked over backwards, or
got off his mule on either side. One of the bad passes called _las
Animas_ (the Souls), I had crossed, and did not find out till a day
afterwards that it was one of the awful dangers. No doubt there are
many parts in which, if the mule should stumble, the rider would be
hurled down a great precipice; but of such a catastrophe there is
much less chance than with a man on foot. I dare say, in the spring,
the “laderas,” or roads, which each year are formed anew across
the piles of fallen detritus, are very bad; but from what I have
seen, I suspect the real danger is nothing, and the apparent very
little. With cargo mules the case is rather different; for the loads
project so far, that the animals occasionally running against each
other, or against a point of rock, lose their balance and are thrown
down the precipice. With regard to crossing the rivers, I can well
believe that the difficulty amounts to every degree, till they are
impracticable. At this season there was little trouble, but in the
summer they must be very bad. I can quite imagine, as Captain Head
describes, the different expressions of those who _have_ passed the
gulf, and those who _are_ passing. I never heard of any man being
drowned, but with loaded mules this is of frequent occurrence. The
arriero tells you to show your mule the best line, and then allow
her to cross as she chooses; the cargo mule takes a bad line, and is
often lost.
APRIL 4TH.--From the Rio de las Vacas to the Puente del Inca, half a
day’s journey. As there was pasture for the mules, and geology for
me, we bivouacked for the night. When one hears of a natural bridge,
one pictures to oneself some deep and narrow ravine, across which a
bold mass of rock has fallen; or a great arch hollowed out like the
vault of a cavern. Instead of this, the Inca’s bridge consists of a
crust of stratified shingle, cemented together by the deposits of the
neighbouring hot springs. It appears as if the stream had scooped
out a channel on one side, leaving an overhanging ledge, which was
at last met by the earth and stones falling down from the opposite
cliff. Certainly an oblique junction, as would happen in such case,
was very distinct on one side. The bridge of the Incas is by no means
worthy of the great monarchs whose name it bears.
Close by, there were some ruins of Indian buildings. These occur in
several other places; the most perfect, which I saw, being the Ruinas
de Tambillos. Small square rooms were there huddled together, but
placed in distinct groups. Some of the doorways were yet standing:
they were formed by a cross slab of stone, but only raised about
three feet high. Ulloa, in his “Noticias Americanas,” remarks on the
lowness of the doors in the ancient Peruvian dwellings. These houses,
when perfect, must have been capable of containing a considerable
number of persons. Tradition says, they were used as halting-places
for the Incas, when they crossed these mountains. Traces of Indian
habitations have been discovered in many parts of the Cordillera,
where it does not appear probable, that they were constructed as mere
resting-places; but yet where the land is as utterly unfit for any
kind of cultivation as it is near the Tambillos or Puente del Inca.
In the Portillo pass I saw one group of such ruins. In the ravine of
Jajuel, near Aconcagua, where there is no pass, I heard of numerous
remains situated at a great elevation, where it is both cold and
extremely sterile. At first I imagined, that these houses were places
of refuge built by the Indians on the first arrival of the Spaniards;
but subsequently I have been almost inclined to speculate on the
possibility of a small change of climate.
In the northern parts of Chile, within the Cordillera of Copiapó, old
Indian houses are found in very many parts: by digging amongst the
ruins, bits of woollen articles, instruments of precious metals, and
heads of Indian corn, are not unfrequently discovered. I had likewise
in my possession the head of an arrow, made of agate, of precisely
the same figure as those now used in Tierra del Fuego. I am aware
that the Peruvian Indians[13] frequently inhabit most lofty and bleak
situations; but in these cases, I was assured by men, who had spent
their lives in travelling the Andes, that very many (_muchisimas_)
houses were found at elevations so great as almost to border on
the perpetual snow, and in parts where there exist no passes, and
where the land produces absolutely nothing, and what is still more
extraordinary, where there is no water. Nevertheless it is the
opinion of the people of the country (although they are much puzzled
by the circumstance), that, from the appearance of the houses, the
Indians must have used them as places of residence. In the Despoblado
(uninhabited valley), near Copiapó, at a spot called Punta Gorda, I
saw the remains of seven or eight square little rooms, which were
of a similar form with those at the Tambillos, but built chiefly of
mud (which the present inhabitants cannot by any means imitate in
durability[14]) instead of with stone. They were situated in the most
conspicuous and defenceless position, at the bottom of a flat broad
valley. There was no water nearer than three or four leagues, and
that only in very small quantity, and bad: the soil was absolutely
sterile;--I looked in vain even for a lichen adhering to the rocks.
At the present day, with the advantage of beasts of burden, a mine,
unless it were very rich, could scarcely be worked there with profit.
Yet the Indians formerly chose it as a place of residence! If at the
present time two or three showers of rain were to fall annually,
instead of one during as many years, as now is the case, a small rill
of water would in all probability be formed in this great valley,
draining a mountainous country; and then, by irrigation (the method
of which was formerly so well understood by the Indians), the soil
might easily be rendered sufficiently productive to support a few
families.
I have certain proofs that this part of the continent of South
America has been elevated, near the coast, at least from four to
five hundred feet, since the epoch of existing shells; and further
inland the rise possibly may have been greater. As the peculiarly
arid character of the climate is evidently a consequence of the
height of the great range of mountains, we may feel almost sure,
that prior to the latter elevations, the atmosphere was not so
completely drained of its moisture as at the present day. At a remote
geological era, it is probable that the Andes consisted of a chain
of islands, which were covered by luxuriant forests; and many of
the trees, in a silicified state, may now be seen embedded in the
upper conglomerates. Of these I measured one which was cylindrical,
with a circumference of fifteen feet. As it is nearly certain that
the mountains have risen slowly, so would the climate likewise
become deteriorated slowly. We need not feel greatly surprised at
walls of stone and hardened mud here lasting for many ages, when
we remember how many centuries the Druidical mounds have withstood
even the climate of England. The only question is, whether the
amount of change, since the introduction of man into South America,
has been sufficient to cause a sensible effect on the atmospheric
moisture, and therefore on the fertility of the valleys in the
upper Cordillera. From the extreme slowness with which there is
reason to believe the continent is rising, the longevity of man as a
species, required to allow of sufficient change, is the most valid
objection to the above speculations: for on the eastern shores of
this continent, we have seen that several animals, belonging to the
same class of mammalia with man, have passed away, while the change
of level between land and water, in that part at least, has been so
small, that it can scarcely have caused any sensible difference in
the climate. I may add, however, that at Lima, the elevation, within
the human epoch, certainly has amounted to between seventy and eighty
feet.
When at Lima, I conversed on this subject[15] with Mr. Gill, a civil
engineer, who had seen much of the interior country. He told me that
a conjecture of a change of climate had sometimes crossed his mind;
but that he thought that the greater portion of land now incapable
of cultivation, but covered with Indian ruins, had been reduced
to that condition, by neglect and subterranean movements injuring
the water conduits, which the Indians formerly constructed on so
wonderful a scale. I may here just mention that these people actually
carried tunnels through hills of solid rock, when such were necessary
to conduct the irrigating streams. Mr. Gill told me, he had been
employed professionally to examine one; he found the passage low,
narrow, crooked, and not of uniform breadth, but of very considerable
length. Is it not most wonderful that any people should have
attempted such operations without the aid of iron or of gunpowder!
Mr. Gill mentioned to me a most interesting, and as far as I am
aware, quite unparalleled case, of the effect of subterranean
disturbances in altering the drainage of a country. Travelling from
Casma to Huaraz (not very far distant from Lima), he found a plain
covered with ruins and marks of ancient cultivation, but now quite
barren. Near it was the dry course of a considerable river, whence
the water for irrigation had formerly been conducted. There was
nothing in the appearance of the watercourse to indicate that the
river had not flowed there a few years previously: in some parts
beds of sand and gravel were scattered, and in others the solid rock
had been worn into a broad channel.[16] It is self-evident that a
person following up the course of a stream, will always ascend at
a greater or less inclination. Mr. Gill was therefore very much
astonished, when walking up the bed of this ancient river, to find
himself suddenly going down hill. He imagined that the slope had a
fall of about forty or fifty feet perpendicular. We here have the
most unequivocal evidence, that a ridge or line of hills has been
uplifted directly across the bed of a stream, which must have been
flowing for many centuries. From the moment the river-course was thus
arched, the water would necessarily be thrown back; and a new channel
would be formed on one side some way above. From that time, also,
the neighbouring plain would lose its fertilizing stream, and become
converted into the desert which it now remains.
APRIL 5TH.--We had a long day’s ride across the central ridge, from
the Inca’s bridge to the Ojos del Agua, which is situated near the
lowest _casucha_ on the western slope. These casuchas are little
round towers, with steps outside to reach the floor, which is
elevated some feet above the ground on account of the snow-drifts.
They are eight in number; and under the Spanish government, were
kept during the winter well stored with food and charcoal, and
each courier had a master-key. Now they only answer the purpose of
caves, or rather dungeons. Seated on some little eminence, they are
not, however, ill suited to the surrounding scene of desolation. The
zigzag ascent of the Cumbre, or the partition of the waters, was very
steep and tedious. The height, according to Mr. Pentland,[17] is
12,454 feet. The road did not pass over any perpetual snow, although
there were patches on either hand. The wind on the summit was
exceedingly cold, but it was impossible not to stop a few minutes to
admire, again and again, the colour of the heavens, and the brilliant
transparency of the atmosphere. The scenery, moreover, was grand.
To the westward there was a fine chaos of mountains, divided by
profound ravines. Generally some snow has fallen before this period
of the season, and it has even happened that the Cordillera has been
finally closed by this time. But we were most fortunate. The sky,
by night and by day, was cloudless, excepting perhaps a few round
little masses of vapour, that floated over the highest pinnacles. I
have often seen these islets in the sky, marking the position of the
Cordillera, when the mountains themselves have been hidden beneath
the horizon.
APRIL 6TH.--In the morning we found some thief had stolen one of
our mules, and the bell of the madrina. We therefore rode only two
or three miles down the valley, and staid there the ensuing day in
hopes of recovering the mule, which the arriero thought had been
hidden in some ravine. The scenery in this part had assumed a Chilian
character: the lower parts of the mountains, dotted over with the
pale evergreen Quillay tree, and with the great candlestick cactus,
certainly are more to be admired than any thing in the bare Eastern
valleys; but I cannot quite agree with the admiration expressed by
some travellers. The extreme pleasure, I suspect, is chiefly owing to
the prospect of a good fire, after escaping from the cold regions
above: and I am sure I most heartily participated in such feelings.
8TH.--We left the valley of the river of Aconcagua, by which we had
descended, and reached in the evening a cottage near the Villa de
St. Rosa. The fertility of the plain was extremely delightful. The
autumn being well advanced, the leaves of many of the fruit-trees
were falling; and of the labourers--some were busy in drying figs
and peaches on the roofs of their cottages; while others were
gathering the grapes from the vineyards. It was a pretty scene; but
that pensive stillness was absent, which makes the autumn in England
indeed the evening of the year.
On the 10th we reached Santiago, where I experienced a very kind and
hospitable reception from Mr. Caldcleugh. My excursion only cost me
twenty-four days, and never did I more deeply enjoy an equal space
of time. A few days afterwards I returned to Mr. Corfield’s house at
Valparaiso.
FOOTNOTES:
[1] Throughout Chile, except between Santiago and Valparaiso, every
thing is conveyed on mules. This is an expensive method of transport,
but unavoidable without good roads and improved waggons. In a troop
of mules, there is generally a muleteer to each six animals.
[2] Scoresby’s Arctic Regions, vol. i., p. 122.
[3] I have heard it remarked in Shropshire, that the water, when the
Severn is flooded from long-continued rain, is much more turbid, than
when it proceeds from the snow melting on the Welsh mountains. The
floods also, in the former case, are said to be more destructive to
the land. D’Orbigny (vol. i., p. 184), in explaining the cause of the
various colours of the rivers in South America, remarks that those
with blue or clear water, have their source in the Cordillera, where
the snow melts.
[4] Measurements made by Dr. Gillies; Edinburgh Journal of Nat. and
Geograph. Science, August, 1830.
[5] Journal of the Royal Geograph. Society for 1835.
[6] Greville’s Scottish Cryptogam. Flora, vol. iv., p. 231.
[7] Journal of Natural and Geographical Science, August, 1830.
[8] Journal of Geograph. Soc., vol. v., p. 12. Mr. Lyell (vol. iv.,
p. 360) has compared the fissures, by which the columnar structure
seems to be determined, to the joints that traverse nearly all rocks,
but which are best seen in the non-stratified masses. I may observe,
in the case of the frozen snow, the columnar structure must be owing
to a “metamorphic” action and not to a process during _deposition_.
[9] This is merely an illustration of the admirable laws first laid
down by Mr. Lyell of the geographical distribution of animals as
influenced by geological changes. The whole reasoning, of course, is
founded on the assumption of the immutability of species. Otherwise
the changes might be considered as superinduced by different
circumstances in the two regions during a length of time.
[10] The species is identical with, or resembles most closely, the
famous _Gryllus migratorius_ of eastern countries.
[11] “And the sound of their wings was as the sound of chariots of
many horses running to battle.”--_Revelat._ ix. 9.
[12] Swarms of locusts sometimes overrun the more central plains of
this continent. In these cases, and likewise as it appears in all
parts of the world, the locusts are bred in desert plains, and thence
migrate towards a more fertile country.
[13] Mr. Pentland even considers, that the love of an elevated
situation is characteristic of the constitution of this
race.--_Geograph. Journ._
[14] Ulloa (Noticias Americanas, p. 302) remarks on the same
circumstance in Peru. He adds, when speaking of the mud bricks,
“which gives room to think that they had some particular method of
working them, that they should become hard, without cracking, the
secret of which the present inhabitants are ignorant of.”
[15] Temple, in his travels through upper Peru or Bolivia, in going
from Potosi to Oruro, says, “I saw many Indian villages or dwellings
in ruins, up even to the very tops of the mountains, attesting a
former population where now all is desolate.” He makes similar
remarks in another place, but it is not possible to judge, whether
this desolation is owing merely to a want of population, or to an
altered condition of the land.
[16] Mr. Gill said he recollected that one part, which had been cut
out of the solid rock, was about forty yards wide and eight feet
deep. This is sufficient to give some idea of the size of the former
stream.
[17] Geographical Journal. Notice on Bolivian Cordillera, March, 1835.