MARCH 7th, 1835. -- We stayed three days at Concepcion,and then sailed for Valparaiso. The windbeing northerly, we only reached the mouth of theharbour of Concepcion before it was dark. Being very nearthe land, and a fog coming on, the anchor was dropped.Presently a large American whaler appeared alongside of us;and we heard the Yankee swearing at his men to keep quiet,whilst he listened for the breakers. Captain Fitz Roy hailedhim, in a loud clear voice, to anchor where he then was. Thepoor man must have thought the voice came from the shore:such a Babel of cries issued at once from the ship -- everyone hallooing out, "Let go the anchor! veer cable! shortensail!" It was the most laughable thing I ever heard. Ifthe ship's crew had been all captains, and no men, there couldnot have been a greater uproar of orders. We afterwardsfound that the mate stuttered: I suppose all hands wereassisting him in giving his orders.

On the 11th we anchored at Valparaiso, and two daysafterwards I set out to cross the Cordillera. I proceeded toSantiago, where Mr. Caldcleugh most kindly assisted me inevery possible way in making the little preparations whichwere necessary. In this part of Chile there are two passesacross the Andes to Mendoza: the one most commonly used,namely, that of Aconcagua or Uspallata -- is situated someway to the north; the other, called the Portillo, is to thesouth, and nearer, but more lofty and dangerous.

March 18th. -- We set out for the Portillo pass. LeavingSantiago we crossed the wide burnt-up plain on which thatcity stands, and in the afternoon arrived at the Maypu, oneof the principal rivers in Chile. The valley, at the pointwhere it enters the first Cordillera, is bounded on each sideby lofty barren mountains; and although not broad, it is veryfertile. Numerous cottages were surrounded by vines, and byorchards of apple, nectarine, and peach-trees -- their boughsbreaking with the weight of the beautiful ripe fruit. In theevening we passed the custom-house, where our luggage wasexamined. The frontier of Chile is better guarded by theCordillera, than by the waters of the sea. There are veryfew valleys which lead to the central ranges, and themountains are quite impassable in other parts by beasts ofburden. The custom-house officers were very civil, whichwas perhaps partly owing to the passport which the Presidentof the Republic had given me; but I must express my admirationat the natural politeness of almost every Chileno. Inthis instance, the contrast with the same class of men inmost other countries was strongly marked. I may mentionan anecdote with which I was at the time much pleased: wemet near Mendoza a little and very fat negress, riding astrideon a mule. She had a _goitre_ so enormous that it was scarcelypossible to avoid gazing at her for a moment; but my twocompanions almost instantly, by way of apology, made thecommon salute of the country by taking off their hats. Wherewould one of the lower or higher classes in Europe, haveshown such feeling politeness to a poor and miserable objectof a degraded race?

At night we slept at a cottage. Our manner of travellingwas delightfully independent. In the inhabited parts webought a little firewood, hired pasture for the animals, andbivouacked in the corner of the same field with them. Carryingan iron pot, we cooked and ate our supper under acloudless sky, and knew no trouble. My companions wereMariano Gonzales, who had formerly accompanied me inChile, 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 wherever she goes, the mules, like good children, followher. The affection of these animals for their madrinas savesinfinite trouble. If several large troops are turned into onefield to graze, in the morning the muleteers have only to leadthe madrinas a little apart, and tinkle their bells; althoughthere may be two or three hundred together, each muleimmediately knows the bell of its own madrina, and comes toher. It is nearly impossible to lose an old mule; for ifdetained for several hours by force, she will, by the powerof smell, like a dog, track out her companions, or rather themadrina, for, according to the muleteer, she is the chiefobject of affection. The feeling, however, is not of anindividual nature; for I believe I am right in saying that anyanimal with a bell will serve as a madrina. In a troop eachanimal carries on a level road, a cargo weighing 416 pounds(more than 29 stone), but in a mountainous country 100pounds less; yet with what delicate slim limbs, without anyproportional bulk of muscle, these animals support so greata burden! The mule always appears to me a most surprisinganimal. That a hybrid should possess more reason, memory,obstinacy, social affection, powers of muscular endurance,and length of life, than either of its parents, seems toindicate that art has here outdone 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 incase we should be snowed up, as the season was rather latefor passing the Portillo.

March 19th. -- We rode during this day to the last, andtherefore most elevated, house in the valley. The number ofinhabitants became scanty; but wherever water could bebrought on the land, it was very fertile. All the main valleysin the Cordillera are characterized by having, on both sides, afringe or terrace of shingle and sand, rudely stratified, andgenerally of considerable thickness. These fringes evidentlyonce extended across the valleys and were united; and thebottoms of the valleys in northern Chile, where there are nostreams, are thus smoothly filled up. On these fringes theroads are generally carried, for their surfaces are even, andthey rise, with a very gentle slope up the valleys: hence, also,they are easily cultivated by irrigation. They may be tracedup to a height of between 7000 and 9000 feet, where theybecome hidden by the irregular piles of debris. At the lowerend or mouths of the valleys, they are continuously united tothose land-locked plains (also formed of shingle) at the footof the main Cordillera, which I have described in a formerchapter as characteristic of the scenery of Chile, and whichwere undoubtedly deposited when the sea penetrated Chile, asit now does the more southern coasts. No one fact in thegeology of South America, interested me more than theseterraces of rudely-stratified shingle. They precisely resemblein composition the matter which the torrents in each valleywould deposit, if they were checked in their course by anycause, such as entering a lake or arm of the sea; but thetorrents, instead of depositing matter, are now steadily atwork wearing away both the solid rock and these alluvialdeposits, along the whole line of every main valley and sidevalley. It is impossible here to give the reasons, but I amconvinced that the shingle terraces were accumulated, duringthe gradual elevation of the Cordillera, by the torrentsdelivering, at successive levels, their detritus on thebeachheads of long narrow arms of the sea, first high up thevalleys, then lower and lower down as the land slowly rose. Ifthis be so, and I cannot doubt it, the grand and broken chainof the Cordillera, instead of having been suddenly thrown up,as was till lately the universal, and still is the commonopinion of geologists, has been slowly upheaved in mass, in thesame gradual manner as the coasts of the Atlantic and Pacifichave risen within the recent period. A multitude of facts in thestructure of the Cordillera, on this view receive a simpleexplanation.

The rivers which flow in these valleys ought rather to becalled mountain-torrents. Their inclination is very great,and their water the colour of mud. The roar which theMaypu 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 from a distance. This rattlingnoise, night and day, may be heard along the wholecourse of the torrent. The sound spoke eloquently to thegeologist; the thousands and thousands of stones, which,striking against each other, made the one dull uniform sound,were all hurrying in one direction. It was like thinking ontime, where the minute that now glides past is irrevocable.So was it with these stones; the ocean is their eternity, andeach note of that wild music told of one more step towardstheir destiny.

It is not possible for the mind to comprehend, except bya slow process, any effect which is produced by a cause repeatedso often, that the multiplier itself conveys an idea,not more definite than the savage implies when he points tothe hairs of his head. As often as I have seen beds of mud,sand, and shingle, accumulated to the thickness of manythousand feet, I have felt inclined to exclaim that causes,such as the present rivers and the present beaches, couldnever have ground down and produced such masses. But, onthe other hand, when listening to the rattling noise of thesetorrents, and calling to mind that whole races of animals havepassed away from the face of the earth, and that during thiswhole period, night and day, these stones have gone rattlingonwards in their course, I have thought to myself, can anymountains, any continent, withstand such waste?

In this part of the valley, the mountains on each side werefrom 3000 to 6000 or 8000 feet high, with rounded outlinesand steep bare flanks. The general colour of the rock wasdullish purple, and the stratification very distinct. If thescenery was not beautiful, it was remarkable and grand. Wemet during the day several herds of cattle, which men weredriving down from the higher valleys in the Cordillera. Thissign of the approaching winter hurried our steps, more thanwas convenient for geologizing. The house where we sleptwas situated at the foot of a mountain, on the summit ofwhich are the mines of S. Pedro de Nolasko. Sir F. Headmarvels how mines have been discovered in such extraordinarysituations, as the bleak summit of the mountain of S.Pedro de Nolasko. In the first place, metallic veins in thiscountry are generally harder than the surrounding strata:hence, during the gradual wear of the hills, they projectabove the surface of the ground. Secondly, almost everylabourer, especially in the northern parts of Chile, understandssomething about the appearance of ores. In the greatmining provinces of Coquimbo and Copiapo, firewood is veryscarce, and men search for it over every hill and dale; andby this means nearly all the richest mines have there beendiscovered. Chanuncillo, from which silver to the value ofmany hundred thousand pounds has been raised in the courseof a few years, was discovered by a man who threw a stoneat his loaded donkey, and thinking that it was very heavy, hepicked it up, and found it full of pure silver: the veinoccurred at no great distance, standing up like a wedge ofmetal. The miners, also, taking a crowbar with them, oftenwander on Sundays over the mountains. In this south partof Chile, the men who drive cattle into the Cordillera, andwho frequent every ravine where there is a little pasture, arethe usual discoverers.

20th. -- As we ascended the valley, the vegetation, withthe exception of a few pretty alpine flowers, became exceedinglyscanty, and of quadrupeds, birds, or insects, scarcelyone could be seen. The lofty mountains, their summitsmarked with a few patches of snow, stood well separatedfrom each other, the valleys being filled up with an immensethickness of stratified alluvium. The features in the sceneryof the Andes which struck me most, as contrasted with theother mountain chains with which I am acquainted, were, --the flat fringes sometimes expanding into narrow plains oneach side of the valleys, -- the bright colours, chiefly red andpurple, of the utterly bare and precipitous hills of porphyry,the grand and continuous wall-like dykes, -- the plainly-divided strata which, where nearly vertical, formed thepicturesque and wild central pinnacles, but where less inclined,composed the great massive mountains on the outskirts of therange, -- and lastly, the smooth conical piles of fine andbrightly coloured detritus, which sloped up at a high anglefrom the base of the mountains, sometimes to a height ofmore than 2000 feet.

I frequently observed, both in Tierra del Fuego and withinthe Andes, that where the rock was covered during the greaterpart of the year with snow, it was shivered in a veryextraordinary manner into small angular fragments. Scoresby

As the evening drew to a close, we reached a singularbasin-like plain, called the Valle del Yeso. It was coveredby a little dry pasture, and we had the pleasant sight of aherd of cattle amidst the surrounding rocky deserts. Thevalley takes its name of Yeso from a great bed, I should thinkat least 2000 feet thick, of white, and in some parts quitepure, gypsum. We slept with a party of men, who wereemployed in loading mules with this substance, which is usedin the manufacture of wine. We set out early in the morning(21st), and continued to follow the course of the river, whichhad become very small, till we arrived at the foot of the ridge,that separates the waters flowing into the Pacific and AtlanticOceans. The road, which as yet had been good with a steadybut very gradual ascent, now changed into a steep zigzagtrack up the great range, dividing the republics of Chileand Mendoza.

I will here give a very brief sketch of the geology of theseveral parallel lines forming the Cordillera. Of these lines,there are two considerably higher than the others; namely,on the Chilian side, the Peuquenes ridge, which, where theroad crosses it, is 13,210 feet above the sea; and the Portilloridge, on the Mendoza side, which is 14,305 feet. The lowerbeds of the Peuquenes ridge, and of the several great linesto the westward of it, are composed of a vast pile, manythousand feet in thickness, of porphyries which have flowed assubmarine lavas, alternating with angular and rounded fragmentsof the same rocks, thrown out of the submarine craters.These alternating masses are covered in the central parts,by a great thickness of red sandstone, conglomerate, andcalcareous clay-slate, associated with, and passing into,prodigious beds of gypsum. In these upper beds shells aretolerably frequent; and they belong to about the period of thelower chalk of Europe. It is an old story, but not the lesswonderful, to hear of shells which were once crawling on thebottom of the sea, now standing nearly 14,000 feet above itslevel. The lower beds in this great pile of strata, have beendislocated, baked, crystallized and almost blended together,through the agency of mountain masses of a peculiar whitesoda-granitic rock.

The other main line, namely, that of the Portillo, is of atotally different formation: it consists chiefly of grand barepinnacles of a red potash-granite, which low down on thewestern flank are covered by a sandstone, converted by theformer heat into a quartz-rock. On the quartz, there restbeds of a conglomerate several thousand feet in thickness,which have been upheaved by the red granite, and dip at anangle of 45 degs. towards the Peuquenes line. I was astonishedto find that this conglomerate was partly composed of pebbles,derived from the rocks, with their fossil shells, of thePeuquenes range; and partly of red potash-granite, like thatof the Portillo. Hence we must conclude, that both the Peuquenesand Portillo ranges were partially upheaved and exposedto wear and tear, when the conglomerate was forming;but as the beds of the conglomerate have been thrown off atan angle of 45 degs. by the red Portillo granite (with theunderlying sandstone baked by it), we may feel sure, that thegreater part of the injection and upheaval of the alreadypartially formed Portillo line, took place after theaccumulation of the conglomerate, and long after the elevationof the Peuquenes ridge. So that the Portillo, the loftiest linein this part of the Cordillera, is not so old as the less loftyline of the Peuquenes. Evidence derived from an inclined streamof lava at the eastern base of the Portillo, might be adducedto show, that it owes part of its great height to elevations ofa still later date. Looking to its earliest origin, the redgranite seems to have been injected on an ancient pre-existingline of white granite and mica-slate. In most parts, perhaps inall parts, of the Cordillera, it may be concluded that each linehas been formed by repeated upheavals and injections; andthat the several parallel lines are of different ages. Onlythus can we gain time, at all sufficient to explain the trulyastonishing amount of denudation, which these great, thoughcomparatively with most other ranges recent, mountains havesuffered.

Finally, the shells in the Peuquenes or oldest ridge, prove,as before remarked, that it has been upraised 14,000 feetsince a Secondary period, which in Europe we are accustomedto consider as far from ancient; but since these shellslived in a moderately deep sea, it can be shown that the areanow occupied by the Cordillera, must have subsided severalthousand feet -- in northern Chile as much as 6000 feet -- soas to have allowed that amount of submarine strata to havebeen heaped on the bed on which the shells lived. The proofis the same with that by which it was shown, that at a muchlater period, since the tertiary shells of Patagonia lived,there must have been there a subsidence of several hundredfeet, as well as an ensuing elevation. Daily it is forced homeon the mind of the geologist, that nothing, not even the windthat blows, is so unstable as the level of the crust of thisearth.

I will make only one other geological remark: althoughthe Portillo chain is here higher than the Peuquenes, thewaters draining the intermediate valleys, have burst throughit. The same fact, on a grander scale, has been remarked inthe eastern and loftiest line of the Bolivian Cordillera,through which the rivers pass: analogous facts have alsobeen observed in other quarters of the world. On the suppositionof the subsequent and gradual elevation of the Portilloline, this can be understood; for a chain of islets wouldat first appear, and, as these were lifted up, the tides wouldbe always wearing deeper and broader channels between them.At the present day, even in the most retired Sounds on thecoast of Tierra del Fuego, the currents in the transversebreaks which connect the longitudinal channels, are verystrong, so that in one transverse channel even a small vesselunder sail was whirled round and round.

About noon we began the tedious ascent of the Peuquenesridge, and then for the first time experienced some littledifficulty in our respiration. The mules would halt every fiftyyards, and after resting for a few seconds the poor willinganimals started of their own accord again. The short breathingfrom the rarefied atmosphere is called by the Chilenos"puna;" and they have most ridiculous notions concerningits origin. Some say "all the waters here have puna;" othersthat "where there is snow there is puna;" -- and this nodoubt is true. The only sensation I experienced was a slighttightness across the head and chest, like that felt on leavinga warm room and running quickly in frosty weather. Therewas some imagination even in this; for upon finding fossilshells on the highest ridge, I entirely forgot the puna in mydelight. Certainly the exertion of walking was extremelygreat, and the respiration became deep and laborious: I amtold that in Potosi (about 13,000 feet above the sea) strangersdo not become thoroughly accustomed to the atmosphere foran entire year. The inhabitants all recommend onions forthe puna; as this vegetable has sometimes been given inEurope for pectoral complaints, it may possibly be of realservice: -- for my part I found nothing so good as the fossilshells!

When about half-way up we met a large party with seventyloaded mules. It was interesting to hear the wild criesof the muleteers, and to watch the long descending stringof the animals; they appeared so diminutive, there beingnothing but the black mountains with which they could becompared. When near the summit, the wind, as generallyhappens, was impetuous and extremely cold. On each side ofthe ridge, we had to pass over broad bands of perpetualsnow, which were now soon to be covered by a fresh layer.When we reached the crest and looked backwards, a gloriousview was presented. The atmosphere resplendently clear;the sky an intense blue; the profound valleys; the wildbroken forms: the heaps of ruins, piled up during the lapseof ages; the bright-coloured rocks, contrasted with the quietmountains of snow, all these together produced a scene noone could have imagined. Neither plant nor bird, exceptinga few condors wheeling around the higher pinnacles, distractedmy attention from the inanimate mass. I felt gladthat I was alone: it was like watching a thunderstorm, orhearing in full orchestra a chorus of the Messiah.

On several patches of the snow I found the Protococcusnivalis, or red snow, so well known from the accounts ofArctic navigators. My attention was called to it, by observingthe footsteps of the mules stained a pale red, as if theirhoofs had been slightly bloody. I at first thought that it wasowing to dust blown from the surrounding mountains of redporphyry; for from the magnifying power of the crystalsof snow, the groups of these microscopical plants appearedlike coarse particles. The snow was coloured only where ithad thawed very rapidly, or had been accidentally crushed.A little rubbed on paper gave it a faint rose tinge mingledwith a little brick-red. I afterwards scraped some off thepaper, and found that it consisted of groups of little spheresin colourless cases, each of the thousandth part of an inch indiameter.

The wind on the crest of the Peuquenes, as just remarked,is generally impetuous and very cold: it is said

Having crossed the Peuquenes, we descended into a mountainouscountry, intermediate between the two main ranges,and then took up our quarters for the night. We were nowin the republic of Mendoza. The elevation was probably notunder 11,000 feet, and the vegetation in consequence exceedinglyscanty. The root of a small scrubby plant served asfuel, but it made a miserable fire, and the wind waspiercingly cold. Being quite tired with my days work, Imade 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 ofbad weather; but he said that without thunder and lightningthere was no risk of a heavy snow-storm. The peril isimminent, and the difficulty of subsequent escape great, toany one overtaken by bad weather between the two ranges.A certain cave offers the only place of refuge: Mr. Caldcleugh,who crossed on this same day of the month, wasdetained there for some time by a heavy fall of snow. Casuchas,or houses of refuge, have not been built in this passas in that of Uspallata, and, therefore, during the autumn,the Portillo is little frequented. I may here remark thatwithin the main Cordillera rain never falls, for during thesummer the sky is cloudless, and in winter snow-storms aloneoccur.

At the place where we slept water necessarily boiled, fromthe diminished pressure of the atmosphere, at a lowertemperature than it does in a less lofty country; the case beingthe converse of that of a Papin's digester. Hence the potatoes,after remaining for some hours in the boiling water,were nearly as hard as ever. The pot was left on the fireall night, and next morning it was boiled again, but yet thepotatoes were not cooked. I found out this, by overhearingmy two companions discussing the cause, they had cometo the simple conclusion, "that the cursed pot [which was anew one] did not choose to boil potatoes."

March 22nd. -- After eating our potatoless breakfast, wetravelled across the intermediate tract to the foot of thePortillo range. In the middle of summer cattle are broughtup here to graze; but they had now all been removed: eventhe greater number of the Guanacos had decamped, knowingwell that if overtaken here by a snow-storm, they would becaught in a trap. We had a fine view of a mass of mountainscalled Tupungato, the whole clothed with unbrokensnow, in the midst of which there was a blue patch, nodoubt a glacier; -- a circumstance of rare occurrence in thesemountains. Now commenced a heavy and long climb, similarto that of the Peuquenes. Bold conical hills of redgranite rose on each hand; in the valleys there were severalbroad fields of perpetual snow. These frozen masses, duringthe process of thawing, had in some parts been convertedinto pinnacles or columns,

When nearly on the crest of the Portillo, we were envelopedin a falling cloud of minute frozen spicula. This wasvery unfortunate, as it continued the whole day, and quiteintercepted 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 clearday, those vast plains which uninterruptedly extend to theAtlantic Ocean can be seen. We descended to the upperlimit of vegetation, and found good quarters for the nightunder the shelter of some large fragments of rock. We methere some passengers, who made anxious inquiries about thestate of the road. Shortly after it was dark the clouds suddenlycleared away, and the effect was quite magical. Thegreat mountains, bright with the full moon, seemed impendingover us on all sides, as over a deep crevice: one morning,very early, I witnessed the same striking effect. Assoon as the clouds were dispersed it froze severely; but asthere was no wind, we slept very comfortably.

The increased brilliancy of the moon and stars at thiselevation, owing to the perfect transparency of the atmosphere,was very remarkable. Travelers having observedthe difficulty of judging heights and distances amidst loftymountains, have generally attributed it to the absence ofobjects of comparison. It appears to me, that it is fully asmuch owing to the transparency of the air confoundingobjects at different distances, and likewise partly to thenovelty of an unusual degree of fatigue arising from a littleexertion, -- habit being thus opposed to the evidence of thesenses. I am sure that this extreme clearness of the airgives a peculiar character to the landscape, all objectsappearing to be brought nearly into one plane, as in a drawingor panorama. The transparency is, I presume, owing tothe equable and high state of atmospheric dryness. Thisdryness was shown by the manner in which woodworkshrank (as I soon found by the trouble my geological hammergave me); by articles of food, such as bread and sugar,becoming extremely hard; and by the preservation of theskin and parts of the flesh of the beasts, which had perishedon the road. To the same cause we must attribute the singularfacility with which electricity is excited. My flannelwaistcoat, when rubbed in the dark, appeared as if it hadbeen washed with phosphorus, -- every hair on a dog's backcrackled; -- even the linen sheets, and leathern straps of thesaddle, when handled, emitted sparks.

March 23rd. -- The descent on the eastern side of the Cordillerais much shorter or steeper than on the Pacific side;in other words, the mountains rise more abruptly from theplains than from the alpine country of Chile. A level andbrilliantly white sea of clouds was stretched out beneath ourfeet, shutting out the view of the equally level Pampas. Wesoon entered the band of clouds, and did not again emergefrom it that day. About noon, finding pasture for the animalsand bushes for firewood at Los Arenales, we stoppedfor the night. This was near the uppermost limit of bushes,and the elevation, I suppose, was between seven and eightthousand feet.

I was much struck with the marked difference betweenthe vegetation of these eastern valleys and those on theChilian side: yet the climate, as well as the kind of soil, isnearly the same, and the difference of longitude very trifling.The same remark holds good with the quadrupeds, and ina lesser degree with the birds and insects. I may instance themice, of which I obtained thirteen species on the shores ofthe Atlantic, and five on the Pacific, and not one of themis identical. We must except all those species, which habituallyor occasionally frequent elevated mountains; and certainbirds, which range as far south as the Strait of Magellan.This fact is in perfect accordance with the geologicalhistory of the Andes; for these mountains have existed asa great barrier since the present races of animals haveappeared; and therefore, unless we suppose the same speciesto have been created in two different places, we ought not toexpect any closer similarity between the organic beings onthe opposite sides of the Andes than on the opposite shoresof the ocean. In both cases, we must leave out of the questionthose kinds which have been able to cross the barrier,whether of solid rock or salt-water.

A great number of the plants and animals were absolutelythe same as, or most closely allied to, 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 characteristicanimals of the desert plains of Patagonia. We havelikewise many of the same (to the eyes of a person who isnot a botanist) thorny stunted bushes, withered grass, anddwarf plants. Even the black slowly crawling beetles areclosely similar, and some, I believe, on rigorous examination,absolutely identical. It had always been to me a subject ofregret, that we were unavoidably compelled to give up theascent of the S. Cruz river before reaching the mountains:I always had a latent hope of meeting with some greatchange in the features of the country; but I now feel sure,that it would only have been following the plains of Patagoniaup a mountainous ascent.

March 24th. -- Early in the morning I climbed up a mountainon one side of the valley, and enjoyed a far extendedview over the Pampas. This was a spectacle to which I hadalways looked forward with interest, but I was disappointed:at the first glance it much resembled a distant view of theocean, but in the northern parts many irregularities weresoon distinguishable. The most striking feature consistedin the rivers, which, facing the rising sun, glittered likesilver threads, till lost in the immensity of the distance. Atmidday we descended the valley, and reached a hovel, wherean officer and three soldiers were posted to examine passports.One of these men was a thoroughbred PampasIndian: 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 passengerendeavoured to escape detection, by making a long circuitover a neighbouring mountain; but this Indian, having bychance crossed his track, followed it for the whole day overdry and very stony hills, till at last he came on his preyhidden in a gully. We here heard that the silvery clouds,which we had admired from the bright region above, hadpoured down torrents of rain. The valley from this pointgradually opened, and the hills became mere water-wornhillocks compared to the giants behind: it then expandedinto a gently sloping plain of shingle, covered with low treesand bushes. This talus, although appearing narrow, must benearly ten miles wide before it blends into the apparentlydead level Pampas. We passed the only house in thisneighbourhood, the Estancia of Chaquaio: and at sunset we pulledup in the first snug corner, and there bivouacked.

March 25th. -- I was reminded of the Pampas of BuenosAyres, by seeing the disk of the rising sun, intersected by anhorizon level as that of the ocean. During the night a heavydew fell, a circumstance which we did not experience withinthe Cordillera. The road proceeded for some distance dueeast across a low swamp; then meeting the dry plain, itturned to the north towards Mendoza. The distance is twovery long days' journey. Our first day's journey was calledfourteen leagues to Estacado, and the second seventeen toLuxan, near Mendoza. The whole distance is over a leveldesert plain, with not more than two or three houses. Thesun was exceedingly powerful, and the ride devoid of allinterest. There is very little water in this "traversia," andin our second day's journey we found only one little pool.Little water flows from the mountains, and it soon becomesabsorbed by the dry and porous soil; so that, although wetravelled at the distance of only ten or fifteen miles fromthe outer range of the Cordillera, we did not cross a singlestream. In many parts the ground was incrusted with asaline efflorescence; hence we had the same salt-lovingplants which are common near Bahia Blanca. The landscapehas a uniform 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 extendsinland from this river, in a sweeping line as far as San Luisand perhaps even further north. To the eastward of thiscurved line lies the basin of the comparatively damp andgreen plains of Buenos Ayres. The sterile plains of Mendozaand Patagonia consist of a bed of shingle, worn smoothand accumulated by the waves of the sea while the Pampas,covered by thistles, clover, and grass, have been formed bythe ancient estuary mud of the Plata.

After our two days' tedious journey, it was refreshing tosee in the distance the rows of poplars and willows growinground the village and river of Luxan. Shortly before wearrived at this place, we observed to the south a ragged cloudof dark reddish-brown colour. At first we thought that itwas smoke from some great fire on the plains; but we soonfound that it was a swarm of locusts. They were flyingnorthward; and with the aid of a light breeze, they overtookus at a rate of ten or fifteen miles an hour. The main bodyfilled the air from a height of twenty feet, to that, as itappeared, of two or three thousand above the ground; "and thesound of their wings was as the sound of chariots of manyhorses running to battle:" or rather, I should say, like astrong breeze passing through the rigging of a ship. Thesky, seen through the advanced guard, appeared like a mezzotintoengraving, but the main body was impervious to sight;they were not, however, so thick together, but that theycould escape a stick waved backwards and forwards. Whenthey alighted, they were more numerous than the leaves inthe field, and the surface became reddish instead of beinggreen: the swarm having once alighted, the individuals flewfrom side to side in all directions. Locusts are not an uncommonpest in this country: already during the season, severalsmaller swarms had come up from the south, where, asapparently in all other parts of the world, they are bred inthe deserts. The poor cottagers in vain attempted by lightingfires, by shouts, and by waving branches to avert theattack. This species of locust closely resembles, and perhapsis identical with, the famous Gryllus migratorius of the East.

We crossed the Luxan, which is a river of considerablesize, though its course towards the sea-coast is veryimperfectly known: it is even doubtful whether, in passing overthe plains, it is not evaporated and lost. We slept in thevillage of Luxan, which is a small place surrounded by gardens,and forms the most southern cultivated district in theProvince of Mendoza; it is five leagues south of the capital.At night I experienced an attack (for it deserves no less aname) of the _Benchuca_, a species of Reduvius, the greatblack bug of the Pampas. It is most disgusting to feel softwingless insects, about an inch long, crawling over one'sbody. Before sucking they are quite thin, but afterwardsthey become round and bloated with blood, and in this stateare easily crushed. One which I caught at Iquique, (for theyare found in Chile and Peru,) was very empty. When placedon a table, and though surrounded by people, if a finger waspresented, the bold insect would immediately protrude itssucker, make a charge, and if allowed, draw blood. No painwas caused by the wound. It was curious to watch its bodyduring the act of sucking, as in less than ten minutes itchanged from being as flat as a wafer to a globular form.This one feast, for which the benchuca was indebted to oneof the officers, kept it fat during four whole months; but,after the first fortnight, it was quite ready to have anothersuck.

March 27th. -- We rode on to Mendoza. The country wasbeautifully cultivated, and resembled Chile. This neighbourhoodis celebrated for its fruit; and certainly nothing couldappear more flourishing than the vineyards and the orchardsof figs, peaches, and olives. We bought water-melons nearlytwice as large as a man's head, most deliciously cool andwell-flavoured, for a halfpenny apiece; and for the value ofthreepence, half a wheelbarrowful of peaches. The cultivatedand enclosed part of this province is very small; thereis little more than that which we passed through betweenLuxan and the capital. The land, as in Chile, owes its fertilityentirely to artificial irrigation; and it is really wonderfulto observe how extraordinarily productive a barrentraversia is thus rendered.

We stayed the ensuing day in Mendoza. The prosperityof the place has much declined of late years. The inhabitantssay "it is good to live in, but very bad to grow rich in."The lower orders have the lounging, reckless manners of theGauchos of the Pampas; and their dress, riding-gear, andhabits of life, are nearly the same. To my mind the townhad a stupid, forlorn aspect. Neither the boasted alameda,nor the scenery, is at all comparable with that of Santiago;but to those who, coming from Buenos Ayres, have justcrossed the unvaried Pampas, the gardens and orchards mustappear delightful. Sir F. Head, speaking of the inhabitants,says, "They eat their dinners, and it is so very hot, they goto sleep -- and could they do better?" I quite agree withSir F. 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 theUspallata pass situated north of Mendoza. We had to crossa long and most sterile traversia of fifteen leagues. Thesoil in parts was absolutely bare, in others covered bynumberless dwarf cacti, armed with formidable spines, and calledby the inhabitants "little lions." There were, also, a fewlow bushes. Although the plain is nearly three thousand feetabove the sea, the sun was very powerful; and the heat aswell as the clouds of impalpable dust, rendered the travellingextremely irksome. Our course during the day lay nearlyparallel to the Cordillera, but gradually approaching them.Before sunset we entered one of the wide valleys, or ratherbays, which open on the plain: this soon narrowed into aravine, where a little higher up the house of Villa Vicenciois situated. As we had ridden all day without a drop ofwater, both our mules and selves were very thirsty, and welooked out anxiously for the stream which flows down thisvalley. It was curious to observe how gradually the watermade its appearance: on the plain the course was quite dry;by degrees it became a little damper; then puddles of waterappeared; these soon became connected; and at Villa Vicenciothere was a nice little rivulet.

30th. -- The solitary hovel which bears the imposing nameof Villa Vicencio, has been mentioned by every traveller whohas crossed the Andes. I stayed here and at some neighbouringmines during the two succeeding days. The geologyof the surrounding country is very curious. The Uspallatarange is separated from the main Cordillera by a long narrowplain or basin, like those so often mentioned in Chile,but higher, being six thousand feet above the sea. Thisrange has nearly the same geographical position with respectto the Cordillera, which the gigantic Portillo line has, but itis of a totally different origin: it consists of various kindsof submarine lava, alternating with volcanic sandstones andother remarkable sedimentary deposits; the whole having avery close resemblance to some of the tertiary beds on theshores of the Pacific. From this resemblance I expected tofind silicified wood, which is generally characteristic of thoseformations. I was gratified in a very extraordinary manner.In the central part of the range, at an elevation of aboutseven thousand feet, I observed on a bare slope some snow-whiteprojecting columns. These were petrified trees, elevenbeing silicified, and from thirty to forty converted intocoarsely-crystallized white calcareous spar. They were abruptlybroken off, the upright stumps projecting a few feetabove the ground. The trunks measured from three to fivefeet each in circumference. They stood a little way apartfrom each other, but the whole formed one group. Mr. RobertBrown has been kind enough to examine the wood: hesays it belongs to the fir tribe, partaking of the characterof the Araucarian family, but with some curious points ofaffinity with the yew. The volcanic sandstone in which thetrees were embedded, and from the lower part of which theymust have sprung, had accumulated in successive thin layersaround their trunks; and the stone yet retained the impressionof the bark.

It required little geological practice to interpret themarvellous story which this scene at once unfolded; though Iconfess I was at first so much astonished that I couldscarcely believe the plainest evidence. I saw the spot wherea cluster of fine trees once waved their branches on theshores of the Atlantic, when that ocean (now driven back700 miles) came to the foot of the Andes. I saw that theyhad sprung from a volcanic soil which had been raised abovethe level of the sea, and that subsequently this dry land,with its upright trees, had been let down into the depths ofthe ocean. In these depths, the formerly dry land wascovered by sedimentary beds, and these again by enormousstreams of submarine lava -- one such mass attaining thethickness of a thousand feet; and these deluges of moltenstone and aqueous deposits five times alternately had beenspread out. The ocean which received such thick masses,must have been profoundly deep; but again the subterraneanforces exerted themselves, and I now beheld the bed ofthat ocean, forming a chain of mountains more than seventhousand feet in height. Nor had those antagonistic forcesbeen dormant, which are always at work wearing down thesurface of the land; the great piles of strata had beenintersected by many wide valleys, and the trees now changedinto silex, were exposed projecting from the volcanic soil,now changed into rock, whence formerly, in a green andbudding state, they had raised their lofty heads. Now,all is utterly irreclaimable and desert; even the lichen cannotadhere to the stony casts of former trees. Vast, andscarcely comprehensible as such changes must ever appear,yet they have all occurred within a period, recent whencompared with the history of the Cordillera; and the Cordilleraitself is absolutely modern as compared with manyof the fossiliferous strata of Europe and America.

April 1st. -- We crossed the Upsallata range, and at nightslept at the custom-house -- the only inhabited spot on theplain. Shortly before leaving the mountains, there was avery extraordinary view; red, purple, green, and quite whitesedimentary rocks, alternating with black lavas, were brokenup and thrown into all kinds of disorder by masses of porphyryof every shade of colour, from dark brown to thebrightest lilac. It was the first view I ever saw, whichreally resembled those pretty sections which geologists makeof the inside of the earth.

The next day we crossed the plain, and followed the courseof the same great mountain stream which flows by Luxan.Here it was a furious torrent, quite impassable, and appearedlarger than in the low country, as was the case with the rivuletof Villa Vicencio. On the evening of the succeeding day,we reached the Rio de las Vacas, which is considered theworst stream in the Cordillera to cross. As all these rivershave a rapid and short course, and are formed by the meltingof the snow, the hour of the day makes a considerable differencein their volume. In the evening the stream is muddyand full, but about daybreak it becomes clearer, and muchless impetuous. This we found to be the case with the RioVacas, and in the morning we crossed it with little difficulty.

The scenery thus far was very uninteresting, comparedwith that of the Portillo pass. Little can be seen beyond thebare walls of the one grand flat-bottomed valley, which theroad follows up to the highest crest. The valley andthe huge rocky mountains are extremely barren: during thetwo previous nights the poor mules had absolutely nothingto eat, for excepting a few low resinous bushes, scarcely aplant can be seen. In the course of this day we crossed someof the worst passes in the Cordillera, but their danger hasbeen much exaggerated. I was told that if I attempted topass on foot, my head would turn giddy, and that there wasno room to dismount; but I did not see a place where anyone might not have walked over backwards, or got off hismule on either side. One of the bad passes, called _lasAnimas_ (the souls), I had crossed, and did not find outtill a day afterwards, that it was one of the awful dangers.No doubt there are many parts in which, if the mule shouldstumble, the rider would be hurled down a great precipice;but of this there is little chance. I dare say, in the spring,the "laderas," or roads, which each year are formed anewacross the piles of fallen detritus, are very bad; but fromwhat I saw, I suspect the real danger is nothing. Withcargo-mules the case is rather different, for the loads projectso far, that the animals, occasionally running againsteach other, or against a point of rock, lose their balance, andare thrown down the precipices. In crossing the riversI can well believe that the difficulty may be very great: atthis season there was little trouble, but in the summer theymust be very hazardous. I can quite imagine, as Sir F.Head describes, the different expressions of those who _have_passed the gulf, and those who _are_ passing. I never heardof any man being drowned, but with loaded mules it frequentlyhappens. The arriero tells you to show your mulethe best line, and then allow her to cross as she likes: thecargo-mule takes a bad line, and is often lost.

April 4th. -- From the Rio de las Vacas to the Puente delIncas, half a day's journey. As there was pasture for themules, and geology for me, we bivouacked here for thenight. When one hears of a natural Bridge, one picturesto one's self some deep and narrow ravine, across which abold mass of rock has fallen; or a great arch hollowed outlike the vault of a cavern. Instead of this, the IncasBridge consists of a crust of stratified shingle cementedtogether by the deposits of the neighbouring hot springs. Itappears, as if the stream had scooped out a channel on oneside, leaving an overhanging ledge, which was met by earthand stones falling down from the opposite cliff. Certainlyan oblique junction, as would happen in such a case, wasvery distinct on one side. The Bridge of the Incas is byno means worthy of the great monarchs whose name itbears.

5th. -- We had a long day's ride across the central ridge,from the Incas Bridge to the Ojos del Agua, which are situatednear the lowest _casucha_ on the Chilian side. Thesecasuchas are round little towers, with steps outside to reachthe floor, which is raised some feet above the ground on accountof the snow-drifts. They are eight in number, andunder the Spanish government were kept during the winterwell stored with food and charcoal, and each courier had amaster-key. Now they only answer the purpose of caves, orrather dungeons. Seated on some little eminence, they arenot, however, ill suited to the surrounding scene of desolation.The zigzag ascent of the Cumbre, or the partition ofthe waters, was very steep and tedious; its height, accordingto Mr. Pentland, is 12,454 feet. The road did not pass overany perpetual snow, although there were patches of it onboth hands. The wind on the summit was exceedingly cold,but it was impossible not to stop for a few minutes to admire,again and again, the colour of the heavens, and thebrilliant transparency of the atmosphere. The scenery wasgrand: to the westward there was a fine chaos of mountains,divided by profound ravines. Some snow generally falls beforethis period of the season, and it has even happened thatthe Cordillera have been finally closed by this time. Butwe were most fortunate. The sky, by night and by day, wascloudless, excepting a few round little masses of vapour, thatfloated over the highest pinnacles. I have often seen theseislets in the sky, marking the position of the Cordillera,when the far-distant mountains have been hidden beneaththe horizon.

April 6th. -- In the morning we found some thief hadstolen one of our mules, and the bell of the madrina. Wetherefore rode only two or three miles down the valley, andstayed 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 sides of the mountains, dotted over with the paleevergreen Quillay tree, and with the great chandelier-likecactus, are certainly more to be admired than the bare easternvalleys; but I cannot quite agree with the admirationexpressed by some travellers. The extreme pleasure, I suspect,is chiefly owing to the prospect of a good fire and of agood supper, after escaping from the cold regions above: andI am sure I most heartily participated in these feelings.

8th. -- We left the valley of the Aconcagua, by which wehad descended, and reached in the evening a cottage near theVilla del St. Rosa. The fertility of the plain was delightful:the autumn being advanced, the leaves of many of thefruit-trees were falling; and of the labourers, -- some werebusy 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 I missed that pensive stillnesswhich makes the autumn in England indeed the eveningof the year. On the 10th we reached Santiago, where I receiveda very kind and hospitable reception from Mr. Caldcleugh.My excursion only cost me twenty-four days, andnever did I more deeply enjoy an equal space of time. Afew days afterwards I returned to Mr. Corfield's house atValparaiso.