Louis Agassiz: His Life and Correspondence - LightNovelsOnl.com
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On one occasion the Ha.s.sler encountered one of those sudden and startling flaws of wind common to the Strait. The breeze, which had been strong all day, increased with sudden fury just as the vessel was pa.s.sing through a rather narrow channel, which gave the wind the additional force of compression. In an inconceivably short time, the channel was lashed into a white foam; the roar of wind and water was so great you could not hear yourself speak, though the hoa.r.s.e shout of command and the answering cry of the sailors rose above the storm. To add to the confusion, a loose sail slatted as if it would tear itself in pieces, with that sharp, angry, rending sound which only a broad spread of loose canvas can make.
It became impossible to hold the vessel against the amazing power of the blast, and the Captain turned her round with the intention of putting her into Borja Bay, not far from which, by good fortune, she chanced to be. As she came broadside to the wind in turning, it seemed as if she must be blown over, so violently did she careen.
Once safely round, she flew before the wind, which now became her ally instead of her enemy, and by its aid she was soon abreast of Borja Bay. Never was there a more sudden transition from chaos to peace than that which ensued as she turned in from the tumult in the main channel to the quiet waters of the bay. The Ha.s.sler almost filled the tiny harbor shut in between mountains. She lay there safe and sheltered in breathless calm, while the storm raged and howled outside. These frequent, almost land-locked coves, are the safety of navigators in these straits; but after this day's experience, it was easy to understand how sailing vessels may be kept waiting for months between two such harbors, struggling vainly to make a few miles and constantly driven back by sudden squalls.
In this exquisite mountain-locked harbor, the vessel was weather-bound for a couple of days. Count Pourtales availed himself of this opportunity to ascend one of the summits. Up to a height of fifteen hundred feet, the rock was characterized by the smoothed, rounded surfaces which Aga.s.siz had observed along his whole route in the Strait. Above that height all was broken and rugged, the line of separation being as defined as on any valley wall in Switzerland. It was again impossible to decide, on such short observation, whether these effects were due to local glacial action, or whether they belonged to an earlier general ice-period.
But Aga.s.siz became satisfied, as he advanced, that the two sets of phenomena existed together, as in the northern hemisphere. The general aspect of the opposite walls of the Strait confirmed him in the idea that the sheet of ice in its former extension had advanced from south to north, grinding its way against and over the southern wall to the plains beyond. In short, he was convinced that, as a sheet of ice has covered the northern portion of the globe, so a sheet of ice has covered also the southern portion, advancing, in both instances, far toward the equatorial regions. His observations in Europe, in North America, and in Brazil seemed here to have their closing chapter.
With these facts in his mind, he did not fail to pause before Glacier Bay, noted for its immense glacier, which seems, as seen from the main channel, to plunge sheer down into the waters of the bay. A boat party was soon formed to accompany him to the glacier.
It proved less easy of access than it looked at a distance. A broad belt of wood, growing, as Aga.s.siz afterward found, on an acc.u.mulation of old terminal moraines, spanned the lower valley from side to side. Through this wood there poured a glacial river, emptying itself into the bay. Strange to say, this glacier-washed forest, touching the ice on one side and the sea on the other, was full of flowers. The red bells of the glossy-leaved Desfontainia, the lovely pink blossoms of the Phylesia, the crimson berries of the Pennetia, stood out in bright relief from a background of mossy tree-trunks and rocks. After an hour's walking, made laborious by the spongy character of the ground,--a mixture of loose soil and decaying vegetation, in which one sank knee-deep,--the gleam of the ice began to s.h.i.+mmer through the trees; and issuing from the wood, the party found themselves in front of a glacier wall, stretching across the whole valley and broken into deep rifts, caves, and creva.s.ses of dark blue ice. The glacier was actually about a mile wide; but as the central portion was pressed forward in advance of the sides, the whole front was not presented at once. It formed a sharp crescent, with the curve turned outward. One of the caves in this front wall was some thirty or forty feet high, about a hundred feet deep, and two or three yards wide at the entrance. At the further end it narrowed to a mere gallery, where the roof was pierced by a circular window, quite symmetrical in shape, through which one looked up to the blue sky and drifting clouds. There must be strange effects in this ice-cavern, when the sun is high and sends a shaft of light through its one window to illuminate the interior.
This first excursion was a mere reconnaissance. An approximate idea of the dimensions of the glacier, and some details of its structure, were obtained on a second visit the following day. The anchorage for the night was in Playa Parda Cove, one of the most beautiful of the many beautiful harbors of the Magellan Strait. It is entered by a deep, narrow slit, cut into the mountains on the northern side of the Strait, and widening at its farther end into a kind of pocket or basin, hemmed in between rocky walls bordered by forests, and overhung by snow and ice-fields. The next morning at half-past three o'clock, just as moonlight was fading before the dawn, and the mountains were touched with the coming day, the reveille was sounded for those who were to return to Glacier Bay.
This time Aga.s.siz divided his force so that they could act independently of each other, though under a general plan laid out by him. M. de Pourtales and Dr. Steindachner ascended the mountain to the left of the valley, following its ridge, in the hope of reaching a position from which they could discover the source and the full length of the glacier. In this they did not succeed, though M. de Pourtales estimated its length, as far as he could see from any one point, to be about three miles, beyond which it was lost in the higher range. It made part of a net-work of glaciers running back into a large ma.s.sif of mountains, and fed by many a neve on their upper slopes. The depth as well as the length of this glacier remains somewhat problematical, and indeed all the estimates in so cursory a survey must be considered as approximations rather than positive results. The glazed surface of the ice is an impediment to any examination from the upper side. It would be impossible to spring from brink to brink of a creva.s.se, as is so constantly done by explorers of Alpine glaciers where the edges of the cracks are often snowy or granular. Here the edges of the creva.s.ses are sharp and hard, and to spring across one of any size would be almost certain death. There is no hold for an Alpine stock, no grappling point for hands or feet. Any investigation from the upper surface would, therefore, require special apparatus, and much more time than Aga.s.siz and his party could give. Neither was an approach from the side very easy. The glacier arches so much in the centre, and slopes away so steeply, that when one is in the lateral depression between it and the mountain, one faces an almost perpendicular wall of ice, which blocks the vision completely. M.
de Pourtales measured one of the creva.s.ses in this wall, and found that it had a depth of some seventy feet. Judging from the remarkable convexity of the glacier, it can hardly be less in the centre than two or three times its thickness on the edges, --something over two hundred feet, therefore. Probably none of these glaciers of the Strait of Magellan are as thick as those of Switzerland, though they are often much broader. The mountains are not so high, the valleys not so deep, as in the Alps; the ice is consequently not packed into such confined troughs. By some of the party an attempt was made to ascertain the rate of movement, signals having been adjusted the day before for its measurement.
During the middle of the day, it advanced at the rate of ten inches and a fraction in five hours. One such isolated observation is of course of little comparative value. For himself, Aga.s.siz reserved the study of the bay, the ancient bed of the glacier in its former extension. He spent the day in cruising about the bay in the steam-launch, landing at every point he wished to investigate. His first care was to examine minutely the valley walls over which the glacier must once have moved. Every characteristic feature, known in the Alps as the work of the glaciers, was not only easily recognizable here, but as perfectly preserved as anywhere in Switzerland. The rounded knolls to which De Saussure first gave the name of roches moutonnees were smoothed, polished, scratched, and grooved in the direction of the ice movement, the marks running mostly from south to north, or nearly so. The general trend of the scratches and furrows showed them to have been continuous from one knoll to another. The furrows were of various dimensions, sometimes shallow and several inches broad, sometimes narrow with more defined limits, gradually pa.s.sing into mere lines on a very smoothly polished surface. Even the curious notches scooped out of the even surfaces, and technically called "coups de gouge," were not wanting. In some places the seams of harder rock stood out for a quarter of an inch or so above adjoining decomposed surfaces; in such instances the dike alone retained the glacial marks, which had been worn away from the softer rock.
The old moraines were numerous and admirably well preserved.
Aga.s.siz examined with especial care one colossal lateral moraine, standing about two miles below the present terminus of the ice and five hundred feet above the sea-level. It consisted of the same rocks as those found on the present terminal moraine, part of them being rounded and worn, while large, angular boulders rested above the smaller materials. This moraine forms a dam across a trough in the valley wall, and holds back the waters of a beautiful lake, about a thousand feet in length and five hundred in width, shutting it in just as the Lake of Meril in Switzerland is held in its basin by the glacier of Aletsch. There are erratics some two or three hundred feet above this great moraine, showing that the glacier must have been more than five hundred feet thick when it left this acc.u.mulation of loose materials at such a height. It then united, however, with a large glacier more to the west. Its greatest thickness, as an independent glacier, is no doubt marked, not by the boulders lying higher up, but by the large moraine which shuts in the lake. The direct connection of this moraine with the glacier in its former extension is still further shown by two other moraines, on lower levels and less perfect, but having the same relation to the present terminus of the ice. The lower of these is only one hundred and fifty feet above the actual level of the glacier. These three moraines occur on the western slope of the bay. The eastern slope is more broken, and while the rounded knolls are quite as distinct and characteristic, the erratics are more loosely scattered over the surface. In mineralogical character they agree with those on the western wall of the bay. Upon the summits of some small islands at the entrance of the bay, there are also some remnants of terminal moraines, formed by the glacier when it reached the main channel; that is, when it was some three miles longer than now.
The more recent oscillations, marking the advance and retreat of the glacier within certain limits, are shown by the successive moraines heaped up in advance of the present terminal wall. The central motion here, as in all the Swiss glaciers, is greater than the lateral, the ice being pushed forward in the middle faster than on the sides. But there would seem to be more than one axis of progression in this broad ma.s.s of ice; for though the centre is pushed out beyond the rest, the terminal wall does not present one uniform curve, but forms a number of more or less projecting angles or folds. A few feet in front of this wall is a ridge of loose materials, stones, pebbles, and boulders, repeating exactly the outline of the ice where it now stands; a few feet in advance of this, again, is another ridge precisely like it; still a few feet beyond, another; and so on, for four or five concentric zigzag crescent-shaped moraines, followed by two others more or less marked, till they fade into the larger morainic ma.s.s, upon which stands the belt of wood dividing the present glacier from the bay.
Aga.s.siz counted eight distinct moraines between the glacier and the belt of wood, and four concentric moraines in the wood itself. It is plain that the glacier has ploughed into the forest within some not very remote period, for the trees along its margin are loosened and half uprooted, though not yet altogether decayed. In the presence of the glacier one ceases to wonder at the effects produced by so powerful an agent. This sheet of ice, even in its present reduced extent, is about a mile in width, several miles in length, and at least two hundred feet in depth. Moving forward as it does ceaselessly, and armed below with a gigantic file, consisting of stones, pebbles, and gravel, firmly set in the ice, who can wonder that it should grind, furrow, round, and polish the surfaces over which it slowly drags its huge weight. At once destroyer and fertilizer, it uproots and blights hundreds of trees in its progress, yet feeds a forest at its feet with countless streams; it grinds the rocks to powder in its merciless mill, and then sends them down, a fructifying soil, to the wooded sh.o.r.e below.
Aga.s.siz would gladly have stayed longer in the neighborhood of Glacier Bay, and have made it the central point of a more detailed examination of the glacial phenomena in the Strait. But the southern winter was opening, and already gave signs of its approach. At dawn on the 26th of March, therefore, the Ha.s.sler left her beautiful anchorage in Playa Parda Cove, six large glaciers being in sight from her deck as she came out. The scenery during the morning had a new scientific interest for Aga.s.siz, because the vessel kept along the northern side of the Strait, while the course hitherto had been nearer the southern sh.o.r.e. He could thus better compare the differences between the two walls of the Strait. The fact that the northern wall is more evenly worn, more rounded than the southern, had a special significance for him, as corresponding with like facts in Switzerland, and showing that the ice-sheet had advanced across the Strait with greater force in its ascending than in its descending path. The north side being the strike side, the ice would have pushed against it with greater force. Such a difference between the two sides of any hollow or depression in the direct path of the ice is well known in Switzerland.
Later in the day, a pause was made in Chorocua Bay, where Captain Mayne's chart makes mention of a glacier descending into the water.
There is, indeed, a large glacier on its western side, but so inaccessible, that any examination of it would have required days rather than hours. No one, however, regretted the afternoon spent here, for the bay was singularly beautiful. On either side, deep gorges, bordered by richly-wooded cliffs and overhung by ice and snow-fields, were cut into the mountains. Where these channels might lead, into what dim recesses of ocean and mountain, could only be conjectured. The bay, with all its inlets and fiords, was still as a church. Voices and laughter seemed an intrusion, and a louder shout came back in echoes from far-off hidden retreats. Only the swift steamer-ducks, as they shot across, broke the gla.s.sy surface of the water with their arrow-like wake. From this point the Ha.s.sler crossed to Sholl Bay, and anch.o.r.ed at the entrance of Smythe's Channel. As sunset faded over the snow mountains opposite her anchorage, their white reflection lay like marble in the water.
CHAPTER 24.
1872: AGE 65.
Picnic in Sholl Bay.
Fuegians.
Smythe's Channel.
Comparison of Glacial Features with those of the Strait of Magellan.
Ancud.
Port of San Pedro.
Bay of Concepcion.
Three Weeks in Talcahuana.
Collections.
Geology.
Land Journey to Santiago.
Scenes along the Road.
Report on Glacial Features to Mr. Peirce.
Arrival at Santiago.
Election as Foreign a.s.sociate of the Inst.i.tute of France.
Valparaiso.
The Galapagos.
Geological and Zoological Features.
Arrival at San Francisco.
The next day forces were divided. The vessel put out into the Strait again for sounding and dredging, while Aga.s.siz, with a smaller party, landed in Sholl Bay. Here, after having made a fire and pitched a tent in which to deposit wraps, provisions etc., the company dispersed in various directions along the sh.o.r.e, geologizing, botanizing, and collecting. Aga.s.siz was especially engaged in studying the structure of the beach itself. He found that the ridge of the beach was formed by a glacial moraine, while acc.u.mulations of boulders, banked up in morainic ridges, concentric with one another and with the beach moraine, extended far out from the sh.o.r.e like partly sunken reefs. The pebbles and boulders of these ridges were not local, or, at least, only partially so; they had the same geological character as those of the drift material throughout the Strait.
The day was favorable for work, and there was little to remind one of approaching winter. A creek of fresh water, that ran out upon one part of the beach, led up to a romantic brook, rus.h.i.+ng down through a gorge bordered by moss-grown trees and carpeted by ferns and lichens in all its nooks and corners. This brook took its rise in a small lake lying some half a mile behind the beach. The collections made along the sh.o.r.e in this excursion were large and various: star-fish, volutas, sea-urchins, sea-anemones, medusae, doris; many small fishes, also, from the tide-pools, beside a number drawn in the seine.
Later in the day, when the party had a.s.sembled around the beach fire for rest and refreshment, before returning to the vessel, their lunch was interrupted by strange and unexpected guests. A boat rounded the point of the beach, and, as it came nearer, proved to be full of Fuegian natives, men, women, children, and dogs, their invariable companions. The men alone landed, some six or seven in number, and came toward the tent. Nothing could be more coa.r.s.e and repulsive than their appearance, in which the brutality of the savage was in no way redeemed by physical strength or manliness. They were almost naked, for the short, loose skins tied around the neck, and hanging from the shoulders, over the back, partly to the waist, could hardly be called clothing. With swollen bodies, thin limbs, and stooping forms; with a childish, yet cunning, leer on their faces, they crouched over the fire, spreading their hands toward its genial warmth, and all shrieking at once, "Tabac! tabac!" and "Galleta!"--biscuit. Tobacco there was none; but the remains of the lunch, such as it was,--hard bread and pork,--was distributed among them, and they greedily devoured it.
Then the one who, judging from a certain deference paid him by the others, might be the chief, or leader, seated himself on a stone and sang in a singular kind of monotonous, chanting tone. The words, as interpreted by the gestures and expressions, seemed to be an improvisation concerning the strangers they had found upon the beach, and were evidently addressed to them. There was something curious in the character of this Fuegian song. Rather recitative than singing, the measure had, nevertheless, certain divisions or pauses, as if to mark a kind of rhythm. It was brought to a close at regularly recurring intervals, and ended always in the same way, and on the same note, with a rising inflection of the voice. When the song was finished, a certain surprise and expectancy in the listeners kept them silent. This seemed to trouble the singer, who looked round with a comical air of inquiring disappointment. Thus reminded, the audience were quick to applaud, and then he laughed with pleasure, imitated the clapping of the hands in an awkward way, and nothing loth, began to sing again.
The recall gun from the Ha.s.sler brought this strange scene to a close, and the party hastened down to the beach, closely followed by their guests, who still clamorously demanded tobacco. Meanwhile the women had brought the boat close to that of the Ha.s.sler at the landing. They all began to laugh, talk, and gesticulate, and seemed a noisy grew, chattering unceasingly, with amazing rapidity, and all together. Their boat, with the babies and dogs to add to the tumult, was a perfect babel of voices. They put off at once, keeping as close as they could to the Ha.s.sler boat, and reaching the vessel almost at the same time. They were not allowed to come on board, but tobacco and biscuit, as well as bright calico and beads for the women, were thrown down to them. They scrambled and s.n.a.t.c.hed fiercely, like wild animals, for whatever they could catch. They had some idea of barter, for when they found they had received all that they were likely to get gratuitously, they held up bows and arrows, wicker baskets, birds, and the large sea-urchins, which are an article of food with them. Even after the steamer had started, they still clung to the side, praying, shrieking, screaming, for more "tabac." When they found it a hopeless chase, they dropped off, and began again the same chanting recitative, waving their hands in farewell.
Always interested in the comparative study of the races, Aga.s.siz regretted that he had no other opportunity of observing the natives of this region and comparing them with the Indians he had seen elsewhere, in Brazil and in the United States. It is true that he and his companions, when on sh.o.r.e, frequently came upon their deserted camps, or single empty huts; and their canoes followed the Ha.s.sler several times, but never when it was convenient to stop and let them come up with the vessel. This particular set were not in a canoe, but in a large boat of English build. Probably they had stolen it, or had found it, perhaps, stranded on the sh.o.r.e. They are usually, however, in canoes of their own making. One can only wonder that people ingenious enough to construct canoes so well modeled and so neatly and strongly put together, should have invented nothing better in the way of a house than a hut built of flexible branches, compared with which a wigwam is an elaborate dwelling. These huts are hood-like in shape, and too low for any posture but that of squatting or lying down. In front is always a scorched spot on the ground, where their handful of fire has smouldered; and at one side, a large heap of empty sh.e.l.ls, showing that they had occupied this place until they had exhausted the supply of mussels, on which they chiefly live. When this is the case, they move to some other spot, gather a few branches, reconstruct their frail shelter, and continue the same life.
Untaught by their necessities, they wander thus, naked and homeless, in snow, mist, and rain, as they have done for ages, asking of the land only a strip of beach and a handful of fire; and of the ocean, sh.e.l.l-fish enough to save them from starvation.
The Ha.s.sler had now fairly entered upon Smythe's Channel, and was anch.o.r.ed at evening (March 27th) in Otway Bay, a lake-like harbor, broken by islands. Mount Burney, a n.o.ble, snow-covered mountain, corresponding to Mount Sarmiento in grandeur of outline, was in full view, but was partially veiled in mist. On the following day, however, the weather was perfect for the sail past Sarmiento Range and Snowy Glacier, which were in sight all day. Blue could not be more deep and pure, nor white more spotless, than their ice and snow-fields. Toward the latter part of the day, an immense expanse of snow opened out a little beyond Snowy Range. It was covered with the most curious snow hummocks, forming high cones over the whole surface, their shadows slanting over the glittering snow in the afternoon suns.h.i.+ne. They were most fantastic in shape, and some fifty or sixty in number. At first sight, they resembled heaped-up mounds or pyramids of snow; but as the vessel approached, one group of them, so combined as to simulate a fortification, showed a face of rock where the snow had been blown away, and it seemed therefore probable that all were alike,--snow-covered pinnacles of rock.
The evening anchorage on the 28th was in Mayne's Harbor, a pretty inlet of Owen's Island. Here the vessel was detained for twenty-four hours by the breaking of the reversing rod. The engineers repaired it to the best of their ability, with such apparatus as they had, but it was a source of anxiety till a port was reached where a new one could be supplied. The detention, had it not been for such a cause, was welcome to the scientific party.
Aga.s.siz found the rounded and moutonnees surfaces and the general modeling of the outlines of ice no less marked here than in the Strait; and in a ramble over the hills above the anchorage, M. de Pourtales came upon very distinct glacial scorings and furrows on dikes and ledges of greenstone and syenite. They were perfectly regular, and could be connected by their trend from ledge to ledge, across intervening s.p.a.ces of softer decomposed rock, from which all such surface markings had disappeared.
The country above Mayne's Harbor was pretty, though somewhat barren. Beyond the narrow belt of woods bordering the sh.o.r.e, the walking was over soggy hummocks, with little growth upon them except moss, lichens, and coa.r.s.e marsh gra.s.s. These were succeeded by ridges of crumbling rock, between which were numerous small lakes. The land seemed very barren of life. Even the sh.o.r.es of the ponds were hardly inhabited. No song of bird or buzz of insect broke the stillness. Rock after rock was turned over in the vain expectation of finding living things on the damp under side at least; and the cus.h.i.+ons of moss were broken up in the same fruitless chase. All was barren and lifeless. Not so on the sh.o.r.e, where the collecting went on rapidly. Dredge and nets were at work all the morning, and abundant collections were made also from the little nooks and inlets of the beach. Aga.s.siz found two new jelly-fishes, and christened them at once as the locality suggested, one for Captain Mayne, the other for Professor Owen.
Near the sh.o.r.e, birds also seemed more abundant. A pair of kelp-geese and a steamer duck were brought in, and one of the officers reported humming-birds flitting across the brook from which the Ha.s.sler's tanks were filled.
Early on the morning of the 30th, while mountains and snow-fields, woodland and water, still lay between moonlight and sunrise, the Ha.s.sler started for Tarn Bay. It was a beautiful Easter Sunday, with very little wind, and a soft sky, broken by few clouds. But such beginnings are too apt to be delusive in this region of wet and fog, and a heavy rain, with thick mist, came up in the afternoon. That night, for the first time, the Ha.s.sler missed her anchorage, and lay off the sh.o.r.e near an island, which afforded some protection from the wind. A forlorn hope was detailed to the sh.o.r.e, where a large fire was kept burning all night, that the vessel might not lose her bearings and drift away. In the morning all was right again, and she kept on her course to Rowlet Narrows.
This pa.s.sage is formed by a deep gorge, cleft between lofty walls over which many a waterfall foams from reservoirs of snow above.
Aga.s.siz observed two old glacier beds on the western side of the pa.s.s--two shallow depressions, lying arid and scored between swelling wooded ridges. He had not met in all the journey a better locality for the study of glacial effects than here. The sides of the channel show these traces throughout their whole length. In this same neighborhood, as a conspicuous foreground on the sh.o.r.e of Indian Reach, to the south of Lackawanna Cove, is a large moraine resembling the "horse-backs," in the State of Maine, New England.
The top was as level as a railroad embankment. The anchorage for the night was in Eden Harbor, and for that evening, at least, it was lovely enough to deserve its name. The whole expanse of its land-locked waters, held between mountains and broken by islands, was rosy and purple in the setting sun. The gates of the garden were closed, however, not by a flaming sword, but by an impenetrable forest, along the edge of which a scanty rim of beach hardly afforded landing or foothold. The collections here, therefore, were small; but a good haul was made with the trawl net, which gathered half-a-dozen species of echinoderms, some small fishes, and a number of sh.e.l.ls. Fog detained the vessel in Eden Harbor till a late hour in the morning, but the afternoon was favorable for the pa.s.sage through the English Narrows, the most contracted part of Smythe's Channel. It is, indeed, a mere mountain defile, through which the water rushes with such force that, in navigating it, great care was required to keep the vessel off the rocks. Her anchorage at the close of the day was in Connor's Cove, a miniature harbor not unlike Borja Bay in the Strait. It was a tranquil retreat. The water-birds seemed to find it so, for the steamer ducks were trailing their long wakes through the water, and a large kind of stormy petrel sailed up to the vessel, and almost put himself into the hands of the sailors, with whom he remained an unresisting prisoner.
Geologically, Aga.s.siz found Connor's Cove of especial interest. It runs east and west, opening on the eastern side of the channel; but the knolls, that is to say, the rounded surfaces at its entrance, are furrowed across the cove, at right angles with it. In other words, the movement of the ice, always from south to north, has been with Smythe's Channel, and across the Strait of Magellan.
Indeed it seemed to Aga.s.siz that all the glacial agency in Smythe's Channel, the trend of the furrows, the worn surfaces whereon they were to be found, and the steepness of southern exposures as compared with the more rounded opposite slopes, pointed to the same conclusion.
On the third of April Aga.s.siz left with regret this region of ocean and mountain, glacier, snow-field, and forest. The weeks he had spent there were all too short for the work he had hoped to do.
Yet, trained as he was in glacial phenomena, even so cursory an observation satisfied him that in the southern, as in the northern hemisphere, the present glaciers are but a remnant of the ancient ice-period.
After two days of open sea and head winds, the next anchorage was in Port San Pedro, a very beautiful bay opening on the north side of Corcovado Gulf, with snow mountains in full sight; the Peak of Corcovado and a wonderfully symmetrical volcanic mountain, Melimoya, white as purest marble to the summit, were clearly defined against the sky. Forests clothed the sh.o.r.e on every side, and the shelving beach met the wood in a bank of wild Bromelia, most brilliant in color. Not only were excellent collections made on this beach, but the sh.o.r.e was strewn with large acc.u.mulations of erratics. Among them was a green epidotic rock which Aga.s.siz had traced to this spot from the Bay of San Antonio on the Patagonian coast, without ever finding it in place. Some of the larger boulders had glacial furrows and scratches upon them, and all the hills bordering the sh.o.r.e were rounded and moutonnee. One of the great charms for Aga.s.siz in the scenery of all this region, and especially in the Strait of Magellan, was a kind of home feeling that it gave him. Although the mountains rose from the ocean, instead of from the plain as in Switzerland, yet the snow-fields and the glaciers carried him back to his youth. To him, the sunset of this evening in the Port San Pedro, with the singular transparent rose color over the snow mountains, and the soft succeeding pallor, was the very reproduction of an Alpine sunset.
The next morning brought a disappointment. From this point Aga.s.siz had hoped to continue the voyage by the inside pa.s.sage between the main-land and the island of Chiloe. This was of importance to him, on account of its geological relation to Smythe's Channel and the Strait of Magellan. In the absence of any good charts of the channel, the Captain, after examining the shoals at the entrance, was forced to decide, almost as much to his own regret as to that of Aga.s.siz, not to attempt the further pa.s.sage. Keeping up the outer coast of Chiloe, therefore, the vessel anch.o.r.ed before Ancud on the 8th of April. It was a heavenly day. The volcanic peak of Osorno and the whole snowy Cordilleras were unveiled. The little town above the harbor, with its outlying farms on the green and fertile hills around, seemed like the very centre of civilization to people who had been so long out of the world. It is said to rain in Ancud three hundred and sixty-five days in the year. But on this particular afternoon it was a very sunny place, and the inhabitants seemed to avail themselves of their rare privilege. Groups of Indians, who had come across the river in the morning to sell their milk in the town, were resting in picturesque groups around their empty milk-cans, the women wrapped in their long shawls, the men in their ponchos and slouched hats; the country people were driving out their double teams of strong, powerful oxen harnessed to wooden troughs filled with manure for the fields; the washerwomen were scrubbing and beating their linen along the roadside; the gardens of the poorest houses were bright with large shrubs of wild fuchsia, and, altogether, the aspect of the little place was cheerful and pretty. Aga.s.siz had but two or three hours for a look at the geology. Even this cursory glance sufficed to show him that the drift materials, even to their special mineralogical elements, were the same as in the Magellan Strait. Here they rested, however, on volcanic soil.
Stopping at Lota for coal, but not long enough for any scientific work, the Ha.s.sler entered Concepcion Bay on the 15th April, and anch.o.r.ed near Talcahuana, where she was to remain some three weeks for the repair of her engine. This quaint, primitive little town is built upon one of the finest harbors on the Pacific coast. Aga.s.siz was fortunate in finding, through the kindness of Captain Johnson, a partially furnished house, where several large vacant rooms, opening on the "patio," served admirably as scientific laboratories. Here, then, he established himself with his a.s.sistants. It was soon understood that every living thing would find a market with him, and all the idle urchins about the town flocked to the house with specimens. An unceasing traffic of birds, sh.e.l.ls, fish, etc., went on there from morning to night, and to the various vendors were added groups of Indians coming to have their photographs taken. There were charming excursions and walks in the neighborhood, and the geology of the region was so interesting that it determined Aga.s.siz to go by land from Talcahuana to Valparaiso, on a search after any glacial tracks that might be found in the valley lying between the Cordillera of the Andes and the Coast Range. Meanwhile the Ha.s.sler was to go on a dredging expedition to the island of Juan Fernandez, and then proceed to Valparaiso, where Aga.s.siz was to join her a fortnight later. Although this expedition was under the patronage of the Coast Survey, the generosity of Mr.
Thayer, so constantly extended to scientific aims, had followed Aga.s.siz on this second journey. To his kindness he owed the possibility of organizing an excursion apart from the direct object of the voyage. This change of plan and its cause is told in the following extract from his general report to Professor Peirce:--
APRIL 27th.
While I was transcribing my Report, Pourtales came in with the statement that he had noticed the first indication of an Andean glacier in the vicinity. I have visited the locality twice since.
It is a magnificent polished surface, as well preserved as any I have ever seen upon old glaciated ground or under glaciers of the present day, with well-marked furrows and scratches. Think of it! a characteristic surface, indicating glacier action, in lat.i.tude 37 degrees south, at the level of the sea! The place is only a few feet above tide level, upon the slope of a hill on which stand the ruins of a Spanish fort, near the fishermen's huts of San Vicente, which lies between Concepcion Bay and the Bay of Aranco. Whether the polished surface is the work of a glacier descending from the Andes to the sea-sh.o.r.e or not, I have not yet been able to determine. I find no volcanic pebbles or boulders in this vicinity, which, after my experience in San Carlos, I should expect all along the sh.o.r.e, if the glaciers of the Andes had descended to the level of the ocean, in this part of the country. The erratics here have the character of those observed farther south. It is true the furrows and scratches of this polished surface run mainly from east to west; but there are some crossing the main trend, at angles ranging from 20 to 30 degrees, and running south-east-north-west.
Moreover, the magnetic variation is 18 degrees 3 degrees at Talcahuano April 23rd, the true meridian bearing to the right of the magnetic. I shall soon know what to make of this, as I start to-morrow for the interior, to go to Santiago and join the s.h.i.+p again at Valparaiso. I have hired a private carriage, to be able to stop whenever I wish so to do. I also take a small seine to fish for fresh water fishes in the many streams intervening between this place and Valparaiso. The trend of the glacial scratches in San Vicente reminds me of a fact I have often observed in New England near the sea-sh.o.r.e, where the glacial furrows dip to a considerable extent eastward toward the deep ocean, while further inland their trend is more regular and due North and South. . .
"I had almost forgotten to say that I have obtained unquestionable evidence of the cretaceous age of the coal deposits of Lota and the adjoining localities, north and south, which are generally supposed to be tertiary lignites. They are overlaid by sandstone containing Baculites! I need not adduce other evidence to satisfy geologists of the correctness of my a.s.sertion. I have myself collected a great many of these fossils, in beds resting upon coal-seams. Ever truly yours,
LOUIS AGa.s.sIZ."