[page] 267 June, 1834. GEOLOGY.

cessary to look out directly for anchorage; for further inland the depth soon becomes extremely great. Captain Cook, in entering Christmas Sound, had first 37 fathom, then 40, 60, and, immediately afterwards, no soundings with 170. This structure of the bottom, I presume, must arise from the sediment deposited near the mouths of the channels, by the opposed tides and swell; and likewise from the enormous degradation of the coast rocks, caused by an ocean harassed by endless gales.

The Strait of Magellan is extremely deep in most parts, even close to the shore. About mid-channel eastward of Cape Froward, Captain King found no bottom with 1536 feet: if, therefore, the water should be drained off, Tierra del Fuego would present a far more lofty range of mountains than it does at present. I will not here enter on any speculations regarding the causes which have produced this remarkable structure, in a district in which the latter movements at least have been those of elevation. I may, however, observe, that pebbles, and great boulders of various and peculiar crystalline rocks, which have undoubtedly travelled from the south-west coast, lie scattered over the whole of the eastern part of Tierra del Fuego. One enormous block of syenite near St. Sebastian Bay was barn-shaped, and had a girth of 47 feet; it projected five feet above the sand, and appeared to be deeply buried. The very nearest point to which we can look for the parent rock, is about ninety miles distant. On the shores of the Strait of Magellan, near Port Famine, numerous semi-rounded fragments of various granites and hornblendic rocks are strewed on the beach, and on the sides of the mountain, to an elevation of thirty or forty feet. Now to this point the high road from the Southern and Western shores passes directly over the great abyss of more than 1500 feet deep. Whatever may have been the means of transport, it has not been one of indiscriminate violence: for the two places, St. Sebastian Bay and Shoal Harbour, where the great fragments are most numerous, certainly existed previously to the last and

[page] 268 TIERRA DEL FUEGO. June, 1834.

smallest change of level, as channels connecting the Strait of Magellan, in the one case with the open sea, and in the other with Otway Water.

The climate of the southern part of South America presents many phenomena of the highest interest. It has long been observed that there exists some essential difference between it, and that of the countries in the northern hemisphere. I have already remarked on the surprising contrast between the rank vegetation of the broken west coast, consequent on the humid climate, as compared with the dry and sterile plains of Patagonia. The clouded and boisterous state of the atmosphere is necessarily accompanied by a decrease in extreme temperature; hence we find that fruits which ripen well, and are very abundant, such as the grape and fig, in lat. 41° on the east coast, succeed very poorly in a lower latitude on the opposite side of the continent.* The result is more strongly marked, if we take Europe as the standard of comparison. In Chiloe, lat. 42°, corresponding to the northern parts of Spain, peaches require the greatest care, and seldom produce fruit; but strawberries and apples succeed to admiration. At Valdivia, lat. 40°, or that of Madrid, standard peaches bear abundantly; grapes and figs ripen, but are far from common; olives seldom even partially ripen, and oranges not at all; yet in Europe this is the parallel most productive of these fruits. Even at Concepcion, lat. 36°, oranges are not abundant, though the other named fruits succeed perfectly. At the Falklands, in the same latitude as the south of England, wheat very seldom comes to maturity; but we ought to feel little surprise at this, when we hear that in Chiloe (lat. 42°) the inhabitants are frequently compelled to cut their corn before it is ready, and bring it into their houses to dry.

With respect to the climate of Tierra del Fuego during

* As there are no settlements on the Patagonian coast, there are few means of comparison. Cherry-trees left by the Spaniards at Port Desire, lat. 48°, still bear fruit, whereas, in Chiloe, on the west coast, 360 miles further north, I believe they do not succeed.

[page] 269 June, 1834. CLIMATE.

the colder parts of the year, Captain King has published some most interesting tables in the Geographical Journal.* The Beagle during this voyage, was employed in the extreme southern parts of the country, from December 18th to February 20th. From the appearance of the vegetation during the first part, and from the weather we experienced at the Falkland Islands, subsequent to the last date, I feel little doubt that these sixty-five days included the best part of the summer. Perhaps if another fortnight had been added, the mean would have been a little higher. The first eighteen of these days were spent partly at sea, near Cape Horn, and we were drifted for a short time by bad weather to nearly ninety miles to the southward. The mean temperature, from observations made every two hours by the officers on board the Beagle, was 45°. During the succeeding thirty-seven days† the Beagle was at anchor in different harbours a few leagues north of Cape Horn, and then the mean from observations at 6 A.M., noon, and 6 P.M., was 50°. The mean, therefore, between these two periods, which include the hottest part of the year, is only 47°.5. The latter of the two periods was unusually warm, but the former much the contrary, and the station where the observations were made was a little further to the southward. The whole of these observations apply to the extreme islands: Captain King's were made in a central position 1° 45' further northward. If from the above considerations we add two degrees and a half to the mean obtained this voyage, the result (50°) will probably give the temperature of the hottest part of the year in central Tierra del Fuego. Captain King gives as the mean temperature of June 32°.97, of July 33°.03, of the first twelve days in August 33°.25;

* Journal of the Royal Geographical Society for the years 1830, 1831.

† The mean of the maxima of these thirty-seven days was only 55°.5, and of the minima 45°.3,—the mean range thus being 10°.2. For the whole sixty-five days, the mean of the maxima was only 51°.7, which certainly is a very wretched summer, and shows how little bright sunshine there can be.

[page] 270 TIERRA DEL FUEGO. June, 1834.

answering to our December, January, and February, which three months appear to be the coldest, and the mean of these is 33°.08.* Dublin is nearly in the same latitude in the northern hemisphere as Port Famine is in the southern, and we will take its temperature as a means of comparison.

	Latitudes.	Summer Temperature	Winter Temperature	Difference.	Mean of Summer and Winter.
Dublin† . . .	53° 21' N.	59° .54	39° .2	20° .34	49o .37
Port Famine .	53   38' S.	50	33  .08	16   .92	41  .54
Difference .	0   17'	9  .54	6  .12	3   .42	7  .83

It will be seen by this that the temperature at Port Famine is very considerably lower, both during summer and winter, than at Dublin, and that at the former the difference between the seasons is not so great, or that the climate is there more equable. It seems the general opinion of those who have visited this country, that the frosts are not so severe or so long as in England. The sealers say that throughout the year they wear the same quantity of clothing. Nevertheless Captain King states, that during the winter of 1828 the temperature was once as low as‡ 12°.6. I have drawn up these rough and approximate statements merely for the sake of illustrating some of the following remarks.

* This mean must be a little too low, because the whole of August is not included. I see Von Buch says, "we can hardly assign to Saltenfiord, Norway (in lat. 67°, or 13° 22' nearer the pole than Port Famine) a higher mean temperature than 34°, nor a higher temperature for the warm month of July than 57°.8." (Travels through Norway, p. 123.) Captain King gives as the mean for February, which probably is the hottest month at Port Famine, only at 51°.1. Some observations made at the Falkland Islands (2° 13' north of Port Famine) which are often quoted, give as the mean for the whole year 47°.3, and for the summer 53°.1. These results are very much higher than what I should have anticipated, from the climate of the neighbouring mainland.

† This line is taken from Barton's Lectures on the Geography of Plants.

‡ In this wretched climate, subject to such extreme cold, is it not most wonderful, that human beings should be able to exist unclothed and without shelter?

[page] 271 June, 1834. VEGETATION.

The kind of climate here described appears to be common to the southern parts of the whole of the southern hemisphere. Although so inhospitable to our feelings, and to most of the plants from the warmer parts of Europe, yet it is most favourable to the native vegetation. The forests, which cover the entire country between the latitudes of 38° and 45°, rival in luxuriance those of the glowing intertropical regions. Whilst in Chiloe (lat. 42°) I could almost have fancied myself in Brazil. Stately trees of many kinds, with smooth and highly coloured barks, are loaded by parasitical plants of the monocotyledonous structure; large and elegant ferns are numerous; and arborescent grasses intwine the trees into one entangled mass, to the height of thirty or forty feet above the ground. Palm-trees grow in lat. 37°; an arborescent grass very like a bamboo in 40°; and another closely-allied kind, of great length but not erect, even as far south as 45°.

In another part of this same hemisphere, which has so uniform a character owing to its large proportional area of sea, Forster found parasitical orchideous plants living south of lat. 45° in New Zealand. Tree-ferns thrive luxuriantly near Hobart Town, in Van Diemen's Land. I measured one there which was exactly six feet in circumference; and its height from the ground to the base of the fronds appeared to be very little under twenty. Mr. Brown says* "an arborescent species of the same genus (Dicksonia) was found by Forster, in New Zealand, at Dusky Bay, in nearly 46° S., the highest latitude in which tree-ferns have yet been observed. It is remarkable that, although they have so considerable a range in the southern hemisphere, no tree-fern has been found beyond the northern tropic: a distribution in the two hemispheres somewhat similar to this has been already noticed respecting the Orchideæ that are parasitical on trees."

Even in Tierra del Fuego, Captain King describes the " vegetation thriving most luxuriantly, and large woody stem-

* Appendix to Flinder's Voyage, pp. 575 and 584.

[page] 272 TIERRA DEL FUEGO. June, 1834.

med trees of Fuchsia and Veronica, in England considered and treated as tender plants, in full flower, within a very short distance of the base of a mountain covered for two-thirds down with snow, and with the temperature at 36°." He states, also, that humming-birds were seen sipping the sweets of the flowers, "after two or three days of constant rain, snow, and sleet, during which time the thermometer had been at the freezing point." I myself have seen parrots feeding on the seeds of the winter's bark, south of latitude 55°.

Although the limit of an almost tropical vegetation extends thus far southward, yet the dearth of living things, both vegetable and animal, on the islands situated even far without the antarctic circle, is surprising, compared with the corresponding parallels in the northern hemisphere. In South Shetland in lat. 62° to 63° (same as Ferroe, or southern part of Norway) Weddell* states, "None of the islands afford any vegetation save a short straggling grass, which is found in very small patches in places where there happens to be a little soil. This, together with a moss similar to that which is found in Iceland, appears in the middle of January, at which time the islands are partially clear of snow." In Deception Island, one of the same group, Lieutenant Kendall, says,† "There was nothing in the shape of vegetation except a small kind of lichen." The island itself is partly composed of ice and volcanic ashes interstratified. Another curious proof of the rigour of the climate is mentioned: "Having observed a mound on the hill immediately above this cove, I opened it, and found a rude coffin, the rotten state of which bespoke its having been long consigned to the earth; but the body had undergone scarcely any decomposition. The legs were doubled up, and it was dressed in the jacket and cap of a sailor, but neither they nor the countenance were similar to those of an Englishman."

Sandwich Land, which is nearly three degrees further from

* Weddell's Voyage, p. 133.

† Geographical Journal, 1830, pp. 65 and 66.

[page] 273 June, 1834. ANTARCTIC ISLANDS.

the pole, is thus described by Captain Cook (February 1st, hottest time in the year, and in same latitude as north of Scotland): "Every part was blocked or filled up with ice, and the whole country, from the summits of the mountains down to the very brink of the cliffs which terminate the coast, covered many fathoms thick with everlasting snow. The cliffs alone were all which was to be seen like land." Again he adds, talking of two islets, "These only were clear of snow, and seemed covered with a green turf." In Georgia, lat. 54° to 55°, the bays are terminated by ice cliffs of considerable height, and, according to Cook, the country "in the very height of summer, is in a manner wholly covered many fathoms deep with frozen snow, but more especially on the south-west coast." The only vegetable is " a strong-bladed grass growing in tufts, wild burnet, and a plant like moss." Although 96 miles long and about ten broad, it possesses not a single quadruped, and only one land bird, namely a small titlark (an Anthus), a specimen of which I procured in the Falklands. This bird, if undescribed, certainly well deserves the name of antarcticus, for although not living within that circle, it inhabits a more inhospitable region than any other terrestrial animal. Anderson, in Cook's Voyage, says, even in Kerguelen Land (an island 120 miles long by 60 broad, and situated in lat. 50°, corresponding to the extreme southern point of England), "The whole catalogue of plants does not exceed sixteen or seventeen, including some sorts of moss, and a beautiful species of lichen which grows upon the rocks higher up than the rest of the vegetable productions. Nor is there even the least appearance of a shrub in the whole country." It is doubtful whether there is a single land bird; and then he adds, "The hills are of a moderate height; yet many of their tops were covered with snow* at this time, though answering to our June." These statements forcibly prove the intemperance of the climate even far without the frozen limits of the antarctic circle.

* I have reason to believe, that icebergs are formed on the coast during a part of the year.

VOL. III.

T

[page] 274 TIERRA DEL FUEGO. June, 1834.

There are no direct observations, by which to judge of the mean temperature of the year in these southern islands. But after reading the above accounts, it will readily be granted that it must be very low. Even in Georgia, in lat. 54°-55°, it is not improbable that the soil is perpetually frozen at a few feet beneath the surface. At Deception Island in lat. 62°-63° from the preservation of the dead body alluded to, and the interstratification of ice with the volcanic ashes, we may feel almost sure that such must be the case. In the northern hemisphere, it is only on the great continents that so low a mean temperature is found in corresponding latitudes. In North America, according to Richardson,* north of lat. 56°, the thaw does not penetrate to a greater depth than three feet. In the Steppes of Siberia, Humboldt† states that to the northward of 62°, the ground between twelve and fifteen feet below the surface is always frozen. In the space, however, between these tw o great northern continents, the line of perpetual congelation rises considerably towards the north.

It is a remarkable meteorological fact, that in the northern and southern hemispheres, a low mean temperature, in latitudes without the frigid zone, is the result of a directly opposite condition of things. In the northern hemisphere the atmosphere is rendered extremely cold, from the radiation of a large extent of country during a long winter; nor is it moderated by the warmer currents of any neighbouring sea : hence the extreme cold of the winter more than counterbalances the heat of summer. In the southern hemisphere, on the other hand, although the winter is moderate, the summer is cold; for a sky constantly clouded rarely permits the rays of the sun to warm the surface (itself a bad absorbent) of the great ocean: hence, the mean temperature of the year falls below the freezing point. It will at once be evident, that a kind of vegetation which requires an equable temperature, will approach much nearer

* Appendix to Back's Expedition,

† Fragmens Asiatiques, vol. ii., p. 386.

[page] 275 June, 1834. HEIGHT OF SNOW-LINE.

the line of perpetual congelation in a climate such as this of the southern hemisphere, than in the opposite one subject to extremes.

The height of the plane of perpetual snow in any country, seems chiefly to be determined by the extreme heat of summer, rather than by the mean of the year. As the summer in Tierra del Fuego is so very wretched, we ought not to feel surprised at the fact stated by Capt. King,—that in the Strait of Magellan, the line descends to about 3500 or 4000 feet. In the northern hemisphere, we must travel about fourteen degrees nearer the pole to meet with so low a limit, namely, between lat. 67° and 70° on the mountains of Norway.

In the Cordillera of South America, between latitudes 41° and 43° 30', the culminant peaks have altitudes pretty nearly equal. Several were measured by the officers of the Beagle with considerable care, by angles of elevation, the positions of the mountains being accurately known. Osorno is 7550 feet; mountain south of Osorno 5609; Minchinmadiva 7046; northern end of same range 6862; Corcovado 7510; Yntales 6725. Not only these points, but a great part of the range* was thickly clothed with snow, in the beginning of February (answering to our August), which descended some way down the mountains, and presented to a distant beholder a perfectly horizontal line. We were assured that the snow, which it appeared must inevitably be the case, remained throughout the year. On January 26th, after a week of uncommonly fine weather, Mr. King measured with a pocket sextant, the angle of this line with the summit of the Corcovado; and subtracting the result from the total height, the snow-line was found to descend to 4480 feet. It is possible that there may have existed some unknown cause of error; but as the average height of the few highest

* Mr. Sulivan, who surveyed this part of Chiloe, informs me, that between Osorno and Yntales, there are probably many mountains which rise to a height of nearly 6000 feet. He says he does not recollect any one summit, which (during January) was not covered with snow.

T 2

[page] 276 TIERRA DEL FUEGO. June, 1834.

peaks in the snow-clad range is under 7000 feet, it is evident that the height of the snow-line cannot at most much exceed 6000 feet.

As this is a point of interest, I shall mention a few other circumstances, by which I think we may come to a nearly definite conclusion. On February 2d (1835) I obtained the last view of the Cordillera; on that day the lower line of the snow descended some way (so as to form a considerable angle with the summit, when viewed from a distance of 61 miles) on the mountain south of Osorno (lat. 41° 20'), which stands by itself, and has a height of 5607 feet. Since arriving in England I have received a letter from Mr. Douglas in Chiloe, who, describing some volcanic phenomena, accidentally mentions the snow-line. He says, on February 20th (same year), on the volcano of Minchinmadiva (lat. 42° 48'), which has an elevation of 7046 feet, lava was ejected from a crater "just above the verge of the snow." Again, on February 27th, he alludes to the summit of the Corcovado (7510 feet) being covered with snow, as was Yntales* (6725 feet) in lat. 43° 30'. Again Mr. Douglas, speaking of the Corcovado, says, "On the 16th of March the snow appeared to cover one-fifth of its (visible) perpendicular height." By this date the snow-line must have attained its greatest height (if, indeed, fresh snow had not fallen); and, as the Corcovado rises in an unbroken slope close to the sea, the proportion covered by snow might be judged of, with some degree of accuracy. The height of the Corcovado (7510 feet) was obtained by three angular measurements, made by the officers on the survey, and the mean nearly agreed with the three separate results. Reflecting on all these circumstances, we may conclude with perfect safety, that the limit of perpetual snow, between the latitudes 41° and 43°, cannot much, if at all, exceed 6000 feet.

Proceeding northward along the Cordillera we find a very

* On January 15th, Yntales, seen from the Northern Chonos Islands, was entirely covered by snow.

[page] 277 une, 1834. HEIGHT OF SNOW-LINE.

different condition of things. In the pass of the Portillo (to the southward of 33°) Dr. Gillies determined barometrically the height of the double range; and he found the two ridges to be respectively 13,210 and 14,365 feet. On March 21st and 22d (1835), shortly before fresh snow fell, I crossed these mountains,* and although there were large masses of snow, there were much greater spaces at some height on each side uncovered. Dr. Gillies† says, "the summit (of the volcano of Peuquenes) is generally‡ covered with snow, and its elevation cannot be less than 15,000 above the level of the sea." From these statements, compared with my observations, the snow-line when I crossed certainly was considerably above 14,365,—we may assume 15,000 as about the limit. From the results obtained by Humboldt, Pentland, Gillies, and King, we are enabled to draw up the following table of the extraordinary range of the snow-line, on the Cordillera of South America :

Latitude.			Height in feet of Snow-line.	Observer.
Equatorial region : Mean result.	⌉ ⌋		15,748	Humboldt.
Bolivia, Lat. 16°-18° S.	⌉ ⌋		17,000	Pentland.§
Central Chile, Lat. 33° S.	⌉ ⌋	⌈ | ⌊	14,500 to 15,000	Gillies.
Chiloe, Lat. 41°-43° S.	⌉ ⌋		6,000	Officers of the Beagle.
Tierra del Fuego, 54° S.	⌉ ⌋	⌈ | ⌊	3,500 to 4,000	King.||

* I crossed the Uspallata Pass on April 5th. The height, as given by Mr. Pentland (Geographical Journal), is 12,454. In the ravines there were some inconsiderable patches of snow, but the general surface was quite bare.

† The Edinburgh Journal of Natural and Geographical Science, August, 1830, p. 316.

‡ I have reason to suspect that the snow-line in Chile is subject to ex-

[page] 278 TIERRA DEL FUEGO. June, 1834.

In considering this table, and beginning from the south, we observe, that through the first twelve degrees, the height of the snow-line rises only a little more than 2000 feet. In this space the climate and productions of the country are in many respects very uniform. In the succeeding nine degrees the rise is no less than nine thousand feet. Before any one pronounces this to be impossible, let him reflect well that the height of the snow-line very much depends on the heat of summer. In Chiloe no fruit, excepting apples and strawberries, comes to perfection; it is even oftentimes necessary to carry the barley and corn into the houses to be ripened :* on the other hand, in central Chile, even the sugar-cane† has been cultivated out of doors, and during a long summer of seven months the sky is seldom clouded, and rain never falls. The island of Chiloe, as well as the neighbouring main-

treme variation. I was told, that during one remarkably dry and long summer, all the snow disappeared from Aconcagua. Not being at the time aware of the extraordinary elevation of this mountain (23,000), I did not closely cross-question my informers. It must be remembered that even in ordinary summers the sky is generally cloudless for six or seven months, that no fresh snow falls, and that the atmosphere is excessively dry. It may be asked whether vast quantities of snow would not, under this condition of circumstances, be evaporated? so that it might be possible that all the snow should disappear from a mountain without the temperature having risen above the freezing point. Mr. Miers (vol. i., p. 384) says he passed the Cordillera by the Cumbre Pass on May 30th, 1819, "when not the smallest vestige of snow was observable in any part of the Andes." Yet Aconcagua is in full view in the approach to this pass. Mr. Miers, in another part (p. 383), makes a general assertion to the same effect.

§ See Mr. Pentland's most interesting paper in the Geograph. Journal, read March 1835.

|| Journal of Geograph. Soc., vol. i., p. 165.

* For this fact I may quote, as additional authority, Aguerros Descripcion Historial de la Provincia de Chiloé, 1791, p. 94.

† Miers's Chile, vol. i., p. 415. It is said that the sugar-cane grew at Ingenio, lat. 32°-33°, but not in sufficient quantity to make the manufacture profitable. In the valley of Quillota, south of Ingenio, I saw some large date palm-trees.

[page] 279 June, 1834. GLACIERS.

land, is concealed by one dense forest, dripping with moisture, and abounding with ferns and other plants that love a humid atmosphere : while the soil of central Chile, where not irrigated, is arid and nearly desert. These two countries, so remarkably opposed to each other in every character, blend together rather suddenly near Concepcion, in lat. 37°. I do not doubt, the plain of perpetual snow undergoes an extraordinary flexure in the district where the forest ceases; for trees indicate a rainy climate, and hence a clouded state of atmosphere.*

From central Chile to Bolivia, a space of 16°, the rise of the snow-line is only 2000 feet. If Bolivia possessed an atmosphere as clear as that of Chile, the limit in all probability would be even higher than the present 17,000. The cause why the limit in the equatorial regions should be lower than in a latitude seventeen degrees to the southward, I leave to those to explain, who have more means of information respecting the dryness and clouded state of the atmosphere in the respective regions.

The presence of glaciers depends on the accumulation of a large mass of snow, subject to some variations of temperature, sufficient partially to thaw, and then reconsolidate the

* The average degree of atmospheric transparency seems to be a most important element in determining the climate of any place. Dr. Richardson (Report to Brit. Assoc. for 1836, p. 131) has remarked that Professor Leslie, from experimenting on the effects of radiation only in an insular climate, deduced theoretical inferences respecting the mean temperature of the year, extremely different from the results obtained under the clear atmosphere of the polar regions. I apprehend central Chile will bear comparison with any part of the world for the clearness of its sky, and Chiloe, for one of an opposite condition : therefore we should not feel surprised, if the effects of two such opposite climates at first appear and malous. The remarkable difference in the height of the snow-line, on the opposite sides of the Himmalaya, has been explained by Humboldt and Jacquemont, on the same principle : and in a like manner, the difference between the heights on the Pyrenees and on Caucasus, the latter mountains being characterized by a climate more excessive, than that of the former.

[page] 280 TIERRA DEL FUEGO. June, 1834.

mass in its downward course. They have been aptly compared to gigantic icicles. The lower limit of glaciers, must depend on that of the parent snow, greatly affected by the form of the land: in Tierra del Fuego the snow-line descends very low, and the mountain sides are abrupt; therefore we might expect to find glaciers extending far down their flanks.* Nevertheless, when on first beholding, in the middle of summer, many of the creeks on the northern side of the Beagle channel terminated by bold precipices of ice overhanging the salt water, I felt greatly astonished. For the mountains from which they descended, were far from being very lofty. Captain FitzRoy from angular measurements considers the general range to have an elevation rather under 4000 feet, with one point called Chain Mountain rising to 4300. Further inland, there is indeed a more lofty mountain of 7000 feet, but it is not directly connected with the glaciers to which I now allude. This range, which exceeds by so little the height of some mountains in Britain, which yet sends down in the middle of summer its frozen streams to the sea-coast, is situated in the latitude of the Cumberland hills.

I was much interested by observing the great difference between the matter brought down by torrents and by glaciers. In the former case a spit of gravel is formed, but in the latter a pile of boulders. On one occasion, the boats being hauled on shore, within the distance of half a mile from a glacier, we were admiring the perpendicular cliff of blue ice, and wishing that some more fragments would fall off, like those we saw floating on the water, at a distance of more than a mile from their source. At last, down came a mass

* In the Alps, Saussure gives 8793 feet as the mean of the lower limit of the snow-line. At Mont Blanc the glacier of Montanvert is said (Encyclo. Metropol.) to descend 12,000 feet below the summit of the mountain, and this will make its base 5160 feet lower than the line of snow. In Norway (See Von Buch) where a glacier first comes down to the water's edge (lat. 67°), it is 3800 below the same line: in Tierra del Fuego the difference must be very nearly the same as in the last case.

[page] 281 June, 1834. GLACIERS.

with a roaring noise, and immediately we saw the smooth outline of a wave travelling towards us. The men ran down as quickly as they could to the boats; for the chance of their being dashed to pieces was evident. One of the seamen just caught hold of the bows, as the curling breaker reached it: he was knocked over and over but not hurt; and the boats, though thrice lifted on high and let fall again, received no damage. This was most fortunate for us, for we were a hundred miles distant from the ship, and we should have been left without provisions or fire-arms.

I had previously observed that some large fragments of rock on the beach had been lately displaced: but until seeing this wave I did not understand the cause. The structure of the creek in which this happened was very curious. One side was formed by a spur of mica slate (of which rock the surrounding mountains were composed); the head by a cliff of ice about forty feet high; and the other side by a promontory which was built up of huge rounded fragments of granite and mica slate, and was more than fifty feet in height. To account for the present position of these blocks, where they must have long remained, for old trees were growing on the upper parts; we must suppose, either that the glacier formerly advanced half a mile further outward, or that the land stood at a rather different level. Whether we are able fully to account, or not, for the height and size of this promontory of boulders, certainly it must have been the work of the glacier. One semi-rounded fragment of granite lying just above high-water mark, was of enormous dimensions. It projected six feet above the sand, and was buried to an unknown depth: its shape was oval with a circumference of thirty yards, so that the longer axis probably measured about ten or eleven. This fragment must have come from the higher parts of the range; for the base of the mountain was entirely composed of mica slate.

The waves caused by the fall of the ice must be a most powerful agent in rounding and heaping together these huge fragments, and likewise in wearing away projecting points of

[page] 282 TIERRA DEL FUEGO. June, 1834.

the solid rock. In Georgia, situated in the very same latitude, Cook, speaking of the great ice-cliffs at the head of every harbour, says, "pieces were continually breaking off, and floating out to sea, and a great fall happened while we were in the bay, which made a noise like cannon." He adds, "It can hardly be doubted, that a great deal of ice is formed here in winter, which in the spring is broken off, and dispersed over the sea. Mr. Sorrell, the boatswain of the Beagle, who has long been accustomed to these seas, informs me, that at this season he has seen small icebergs, with mud and gravel on them, floating from the shores. I have heard from another quarter of the same circumstance. Captain Hunter* says, he met numerous ice-islands in this neighbourhood, and that "many were half black apparently with earth from the land, to which they had adhered, or else with mud from the bottom on which they had been formed." By the latter method large fragments might easily be transported, and unless the iceberg should be upset, they would never be discovered. Nevertheless, the islands of ice floating in the southern ocean, and especially those occurring far south, appear generally to be quite free from all impurities excepting the dung of seafowl. Captain Biscoe, who extended his enterprising researches so far towards the antarctic pole, informs me in a letter that he never observed in a single instance† any mud or fragments of stone on the numerous icebergs which he encountered during his voyage.

Glaciers occur at the head of the sounds along the whole western coast of the southern part of South America. Looking at the chart I find sixteen places mentioned: besides these I know of several others, such as those in the Beagle channel and at the foot of Mount Sarmiento. The sounds, moreover, were not all traced to the head, and it is in this part that the glaciers most frequently occur. Of the sixteen referred to, many include several frozen arms coming down

* Hunter's Voyage to Port Jackson, p. 102.

† Mr. Sorrell says, that he once saw an iceberg to the eastward of South Shetland, with a considerable block of rock lying on it.

[page] 283 June, 1834. GLACIERS.

from one vast body of ice. In the Canal of the Mountains, for instance, no less than nine descend from a mountain, the whole side of which, according to the chart, is covered by a glacier of the extraordinary length of twenty-one miles, and with an average breadth of a mile and a half. It must not be supposed that the glacier merely ascends some valley for the twenty-one miles, but it extends apparently at the same height for that length, parallel to the sound; and here and there sends down an arm to the sea-coast.* There are other glaciers having a similar structure and position, with a length of ten and fifteen miles.

I will now specify a few of the more remarkable cases, taken from Captain King's paper, to which I have so often referred. The canal of St. Andrew is said by Lieutenant Skyring to be "suddenly and boldly closed by tremendous and astonishing glaciers." The highest mountain in this part (Mount Stokes) was ascertained during our ascent of the river of St. Cruz to be 6200 feet, and this certainly exceeds considerably the height of the general range. About ninety miles to the northward, Sir G. Eyre's Sound, in the latitude of Paris, has its several arms terminated by glaciers. Mr. Bynoe, the surgeon of the Beagle, who accompanied the boat when this part was surveyed, informs me that about mid-channel, and more than twenty miles from the head of the sound, there were great numbers of floating masses of ice. Standing in the boat he supposes he saw about fifty: he, together with four of the boat's crew, landed on one, which although only two or three feet above the surface of the water, felt quite steady, and easily supported their weight. On the surface, in the central part, a mass of granite, of an angular form, was partly embedded; and the

* I may remark that in the chart, the greater number of the creeks which receive the glaciers, have crosses drawn in front, which signify projecting masses of rock. After what we have seen in the Beagle channel, I suspect that they are detached masses brought down by the overwhelming force of the glaciers.

[page] 284 TIERRA DEL FUEGO. June, 1834.

ice had thawed all round it, so as to form a shallow pool of water. It was a cube of nearly two feet; and Mr. Bynoe with a maul knocked off, and brought away, a piece as large as a man's head. The iceberg was still floating, and drifting outwards: even if it had been stranded in the immediate neighbourhood, the block of granite would have rested on the clay-slate of the surrounding mountains. For the parent rock we must look to the higher parts of the range, near the head of the sound.

Again, a few miles to the northward I see in the chart an Iceberg Sound, which no doubt was so called from the number of floating masses of ice. It may be recollected that in this latitude, on the opposite side of the Cordillera, the plains of St. Cruz, at the distance of fifty and sixty miles from the mountains, were strewed with great fragments of rock. Of these, one was sixty feet in circumference, and another, which was angular, measured five yards square;—both being partly buried in the gravel, so that their thickness was unknown. As it is probable that the plains were covered by the sea within a period geologically recent, and as we absolutely know, that icebergs at the present day, both in the same latitude and even further northward, are transporting angular blocks from the opposite side of the Cordillera, the explanation of the St. Cruz case through the same means of transport, is rendered so evidently probable, that we are not justified in doubting to receive it: more especially as the unbroken surface of those plains, and the terrace-formed valley, opposes a very great difficulty to the admission of any violent debacle. The latitudes which we have now been talking of, correspond to the southern extremity of Cornwall, and the northern provinces of France.

I will add only one other case; namely, the occurrence of glaciers at the level of the sea, in the gulf of Penas, latitude 46° 40'. A glacier is represented in the charts as in one part abutting on a flat swamp often inundated, and in ano-

[page] 285 June, 1834. GLACIERS.

ther reaching to the head of Kelly Harbour. The accompanying wood-cut is copied from the published charts.

Captain King says its length is fifteen miles, and from the chart one part is seven broad; it is also described as being lofty; so that we here have an enormous mountain, covering a wide area, composed of ice. If we compare its situation with countries in the northern hemisphere, the corresponding parallel crosses the Alps of Switzerland. Or we may state the case stronger, by saying that glaciers here descend to the sea within less than nine degrees of latitude, from where palms grow, less than two and a half from arborescent grasses, and (looking to the westward in the same hemisphere) less than two from orchideous parasites, and within a single degree of tree-ferns! In Norway, Von Buch found glaciers descending to the sea at Kunnen in latitude 67°; that is twenty degrees nearer the pole, than in this hemisphere;—a difference of latitude rather greater than that between the snow-lines of equal altitude in the same two countries.

The survey of the inner coast terminated at the gulf of Penas, so that I am far from knowing whether glaciers are not

[page] 286 TIERRA DEL FUEGO. June, 1834.

found much further northward: and considering the immense size of the one just described, it is extremely improbable that it should be the last. On the island of Chiloe, which fronts the Cordillera as the Jura does the Alps, many angular fragments of granite, of an enormous size, which appear to have crossed the inland arm of sea, lie scattered at different heights over the country. Although situated between the parallels of 41° and 43°, I know of no sound objection to the supposition that these might formerly have been floated across, on icebergs produced by the fall of glaciers. We are not bound to suppose that the latitude 46° 40' has always been the northern limit of such phenomena, even if it should be so at present. We have endeavoured to show that the snow-line in the parallel of Chiloe has an elevation of about 6000 feet; and since on Mont Blanc the glaciers descend 5160 feet beneath the line of perpetual snow, we might at present expect to find them in front of Chiloe at a very small altitude above the level of the sea.

With respect to the position of the glaciers, they seem to occur only within the deep sounds which penetrate the central Cordillera. This may be attributed chiefly to the subordinate elevation of the outer lines. When we consider the vast dimensions and number of these glaciers, the effect produced on the land must be very great. Every one has heard of the mass of rubbish propelled by the glaciers of Switzerland, as they slowly creep onwards. In the same manner in Tierra del Fuego, on a still night the cracking and groaning of the great moving mass may be distinctly heard. The same force, which is known to uproot whole forests of lofty trees, must, when grating over the surface, tear from the flanks of the mountain many huge fragments of rock. Beneath each glacier, also, a roaring torrent drains the upper part of the ice. To these effects, which are common to all cases, there must be added, in this country, the wear and tear of the waves produced by each successive fall. Nor can this agency be inconsiderable, when we remember that it goes on night and day, century after century. We must look

[page] 287 June, 1834. GLACIERS.

at every portion of the mountain as having, during the gradual rising of the land, been successively exposed to the action of these combined forces.

It is, perhaps, useless to speculate on the effects of earthquakes without some positive data. But as we find in the immediate neighbourhood of that great glacier, which stands in the latitude of the Alps, Byron* mentioning with surprise the quantities of sea-shells lying on all the hill-tops (a fact which may be taken as a proof of recent continental elevations); and Bulkeley,† in his narrative, saying, "This day we felt four great earthquakes, three of which were very terrible;" we may feel well assured, that the same power, which in Chile causes such vast masses of rock and soil to fall from the sea-cliffs, has oftentimes precipitated fragments far more immense, of a mass traversed by great fissures, already in motion, and resting on an inclined plane. I cannot imagine any scene of more terrific violence, than the waves produced by such a fall: we know that they are very bad from the mere oscillation, consequent on the movements of the ground; but in this case I can readily believe that the water would be fairly beaten back out of the deepest inlet, and then returning with an overwhelming force, would whirl about rocks of vast size like so much chaff.

In after ages, with a climate modified by the process of such physical changes as are now going on throughout the greater part of this continent, the effects which had been produced by these glaciers would appear inexplicable, to a person who doubted the possibility of their occurrence in such latitudes. He would see in the most retired and protected valleys (the present channels) beaches composed of great rounded boulders, such as those heaped up on the shore of the most turbulent ocean. Then perhaps he would speculate, either that the outer chain of mountains had been elevated

* Byron's Narrative of the Shipwreck of the Wager.

† Bulkeley's and Cummin's Faithful Narrative of the loss of the Wager. The earthquake happened August 25, 1741.

[page] 288 TIERRA DEL FUEGO. June, 1834.

subsequently to the interior ones, so as to protect a coast hitherto exposed, or that overwhelming deluges had swept down the valleys, and in some manner produced, in one day, the effects of attrition which on ordinary occasions require the prolonged action of centuries.

If we could at the present day submerge the greater part of Tierra del Fuego, or leave unelevated that which we know has recently been gained, an island with a few small outliers would be formed, similar to Georgia, and situated in exactly the same latitude. Have we in such case the slightest right to deny the probability that the snow-line would descend nearly to the water's edge, and that every valley would be "terminated by a wall of ice," and that "in winter masses would be broken off and dispersed over the sea?"—all of which circumstances are now happening in Georgia. The currents, which always set from the westward towards the east, would drift these floating masses through the channels towards the eastern side. And as we know that icebergs at the present day, in both hemispheres, occasionally transport fragments of rock, so we cannot deny that those of Tierra del Fuego might formerly have done so. When the land was elevated, the fragments of rock would be found deposited on the eastern side of the continent, in bands representing the ancient channels. Whether or not the hypothesis of their transport be true, such is the position of the erratic blocks in Tierra del Fuego.

With respect to the general theory of the transport by great fragments of ice, especially of such as are angular, I may add a few remarks. Humboldt having observed that none occurred over the vast intertropical plains of the eastern side of South America, believed that they were entirely absent from the whole continent. As far as I am able to discover from the works of travellers, and from what I have myself seen, the remark holds good in the countries on both sides of the Cordillera as far south as central Chile. Azara has particularly stated such to be the case in Chaco. With respect to the tributaries of the Amazons, nothing can more

[page] 289 June, 1834. ERRATIC BLOCKS.

strongly prove it than La Condamine's* story. He says, " Below Borja even for four or five hundred leagues, a stone, even a single flint, is as great a rarity as a diamond would be. The savages of those countries don't know what a stone is, and have not even a notion of it. It is diversion enough to see some of them when they come to Borja, and first meet with stones, express their admiration at them with signs, and be eager to pick them up, loading themselves therewith as with a valuable merchandise." It is therefore a remarkable circumstance that as soon as we reach the colder latitudes in the southern hemisphere (from 41° to Cape Horn), the same phenomenon occurs, almost on as grand a scale and with similar limits, as in the northern parts both of the Old and New World. Neither in the southern nor in the northern hemisphere do the fragments, coming from the polar regions, or from other mountain groups, arrive within a considerable distance of the lines of the tropics.

We must couple the absence of erratic blocks along that part of the Andes which is situated under a warmer climate, with the similar non-occurrence, as I am informed by Professor Royle, in Northern India round the flanks of the Himmalaya;—those loftiest pinnacles on the face of the globe. With regard to Southern Africa, from lat. 35° to the tropic, Dr. Andrew Smith, who has visited as a naturalist so large a portion of the interior, assures me he has never seen any thing of the kind. Nor do I recollect meeting with any mention of them, in the works of the numerous travellers in the equatorial regions of the same continent. The same remark certainly holds good with Australia in the parallel of Sydney, but perhaps is more doubtful with respect to Van Diemen's Land.† To my mind these negative facts‡ have

* La Condamine's Voyage (English translation), p. 24.

† I will here put together all the (apparent?) exceptions which I have met with to the supposed law that erratic blocks are absent in the intertropical regions of the world. First, in the Bulletin de la Société Géologique, 1837, p. 234, there is an account of some erratic blocks near Macao (lat. 22° N.); but as it is distinctly stated they are all of granite,

VOL. III.

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[page] 290 TIERRA DEL FUEGO. June, 1834.

very great weight in support of the mass of positive evidence which Mr. Lyell* has brought to bear upon the question.

and the greater number of even the same coloured variety, as the granitic rock, on which they rest, the case need not be considered. Secondly, in a late number of the Madras Journal, Dr. Benza has described some erratic blocks lying on a plain between the Neilgherries (lat. 12° N.) and Madras. He states that the foundation-rock of the country is gneiss, "while the granite clusters are more elevated, and affect either a prismatic form, or are piled up one on the other, like logging stones." Dr. Benza had the kindness to inform me that these masses are very large, and that several are piled one upon the other. Again, Brongniart says (Tableau de Terrains, p. 83), "On cite aussi dans l'Inde, au pays d'Hyderabad (lat. 17° N.), des blocs énormes de granite, amoncelés les uns sur les autres "(Deluc neveu). Every one must draw his own conclusions from these accounts, regarding the probability of erratic blocks being heaped up, one upon the other, like logging stones. The same doubt likewise partly applies to the Macao case. With respect to the boulders of Hyderabad, Dr. T. Christie has distinctly stated (Edin. New Phil. Jour., Oct. 1828, p. 102), that they are in situ, and has explained their origin. For my own part, I cannot forget that whole granitic hills at the Cape of Good Hope, which, from weathering, have assumed a boulder-like form, were once described as transported masses. The two next cases do not properly come under consideration, for they refer to masses lying in the valleys of lofty mountains. We must not overlook such accidents as bursting of lakes, earthquakes, and the action of former coast-lines. Helms, in his Travels (English translation, p. 45), states he was astonished to find the highest snow-capped mountains near Potosi (20° N.) covered with a stratum of rounded granitic stones. He supposes they must have come from Tucuman, which is several hundred miles distant: yet at p. 55 he says, at Iocalla (a few leagues only from Potosi), "a mass of granite many miles in length, rises in huge weatherbeaten rocks :" the whole account is to me quite unintelligible. Lastly, M. Gay (Annales des Sciences, 1833) describes granitic boulders within the valley of Cauquenes (lat. 33°-34° S.), in the Cordillera. I visited this place: the boulders and pebbles are not large, and those beyond the mouth of the valley are small. The case did not appear to me nearly so extraordinary as it seems to have struck M. Gay. I cannot agree with his assertion that this rock is not found in that part of the Cordillera: but this is a subject which I shall discuss in a future work.

‡ The absence of great embedded fragments in the formations of the secondary epoch, when we know that the climate was of a more tropical character, is a fact of the same kind.

[page] 291 June, 1834. RECAPITULATION.

The circumstance of a luxuriant vegetation with a tropical character so largely encroaching on the temperate zones, under the same kind of climate that allows of a limit of perpetual snow of little altitude, and consequent descent of the glaciers into the sea, is very important; because it has been argued, with great apparent truth, that as there is the strongest presumptive evidence of a gradual cooling down of the climate (or rather of a less favourable state for tropical productions) in Europe, it is most unphilosophical to imagine that formerly glaciers could have acted where they do not now occur. It may be asked; what are the circumstances in the southern hemisphere that produce such results? Must we not attribute them to the large proportional area of water; and do not plain geological inferences compel us to allow, that during the epoch anterior to the present, the northern hemisphere more closely approached to that condition, than it now does?

We are all so much better acquainted with the position of places in our own, than in any other quarter of the globe, that I will recapitulate what is actually taking place in the southern hemisphere,† only transporting in imagination each part to a corresponding latitude in the north. On this supposition, in the southern provinces of France, magnificent forests, intwined by arborescent grasses, and the trees loaded with parasitical plants, would cover the face of the country. In the latitude of Mont Blanc, but on an island as far eastward as central Siberia, tree-ferns and parasitical orchideæ would thrive amidst the thick woods. Even as far north as central Denmark, humming-birds might be seen fluttering about delicate flowers, and parrots feeding amidst the evergreen woods, with which the mountains would be clothed down to the water's edge. Nevertheless, the southern part of Scot-

* Anniversary Address to the Geological Society, Feb. 19, 1836, p. 30; and Principles of Geology, vol. i., p. 269, and vol. iv., p. 47, fifth edition.

† It is in the southern hemisphere that we find elephants, rhinoceroses, hippopotomuses, and lions, as far south as lat. 34° 35'. In South America the jaguar occurs in 42°, and the puma in 53°.

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[page] 292 TIERRA DEL FUEGO. June, 1834.

land (only removed twice as far to the westward) would present an island "almost wholly covered with everlasting snow," and having each bay terminated by ice-cliffs, from which great masses yearly detached, would sometimes bear with them fragments of rock. This island would only boast of one land bird, a little grass and moss; yet in the same latitude the sea might swarm with living creatures. A chain of mountains, which we will call the Cordillera, running north and south through the Alps (but having an altitude much inferior to the latter), would connect them with the central part of Denmark. Along this whole line nearly every deep sound would end in "bold and astonishing glaciers." In the Alps themselves (with their altitude reduced by about half) we should find proofs of recent elevations, and occasionally terrible earthquakes would cause such masses of ice to be precipitated into the sea, that waves tearing all before them, would heap together enormous fragments, and pile them up in the corners of the valleys. At other times, icebergs, "charged with no inconsiderable blocks of granite,"* would be floated from the flanks of Mont Blanc, and then stranded on the outlying islands of the Jura. Who then will deny the possibility of these things having actually taken place in Europe during a former period, and under circumstances known to be different from the present, when on merely looking to the other hemisphere, we see they are among the daily order of events?

To the northward of our new Cape Horn, we should only have certain knowledge of a few island groups, situated in the latitude of the south part of Norway, and others in that of Ferroe. These, in the middle of summer, would be buried under snow, and surrounded by walls of ice; so that scarcely a living thing of any kind would be supported on the land. If some bold navigator attempted to penetrate beyond these islands towards the pole, he would run a

* Geographical Journal. Capt. King uses these words when alluding to the case in Sir G. Eyre's Sound, which I have more fully described from the information of Mr. Bynoe.

[page] 293 June, 1834. ANIMALS PRESERVED IN ICE.

thousand dangers, and only meet an ocean strewed with mountain-masses of ice.

At the Ferroe islands (or we may say a little to the southward of the Wiljui, where Pallas found (in lat. 64° N.) the frozen rhinoceros), a body buried under the surface of the soil would undergo so little decomposition, that years afterwards (as in the instance mentioned at South Shetland, 62°-63° S.), every feature might be recognised perfect and unchanged. I particularly allude to this circumstance, because the case of the Siberian animals preserved with their flesh in the ice, offers the same apparent difficulty with the glaciers; namely, the union in the same hemisphere of a climate in some senses severe, with one allowing of the life of those forms which at present, although abounding without the tropics, do not approach the frozen zones.

The perfect preservation of the Siberian animals, perhaps presented, till within a few years, one of the most difficult problems which geology ever attempted to solve. On the one hand it was granted, that the carcasses had not been drifted from any great distance by any tumultuous deluge, and on the other it was assumed as certain, that when the animals lived, the climate must have been so totally different, that the presence of ice in the vicinity was as incredible, as would be the freezing of the Ganges. Mr. Lyell in his "Principles of Geology"* has thrown the greatest light on this subject, by indicating the northerly course of the existing rivers with the probability that they formerly carried carcasses in the same direction ; by showing (from Humboldt) how far the inhabitants of the hottest countries sometimes wander; by insisting on the caution necessary in judging of habits between animals of the same genius, when the species are not identical; and especially by bringing forward in the clearest manner the probable change from an insular to an extreme climate, as the

* In the fourth and subsequent editions.

[page] 294 TIERRA DEL FUEGO. June, 1834.

consequence of the elevation of the land, of which proofs have lately been brought to light.*

In a former part of this volume, I have endeavoured to prove, that as far as regards the quantity of food, there is no difficulty in supposing that these large quadrupeds inhabited sterile regions, producing but a scanty vegetation. With respect to temperature, the woolly covering both of the elephant and the rhinoceros seems at once to render it at least probable (although it has been argued that some animals living in the hottest regions are thickly clothed) that they were fitted for a cold climate. I suppose no reason can be assigned why, during a former epoch, when the pachydermata abounded over the greater part of the world, some species should not have been fitted for the northern regions, precisely as now happens with deer and several other animals.† If, then, we believe that the climate of Siberia, anteriorly to the physical changes above alluded to, had some resemblance with that of the southern hemisphere at the present day—a circumstance which harmonizes well with other facts,‡ as I think has

* Wrangel's Voyage in the Icy Sea in the years 1821, 1822, and 1823. Edited by Professor Parrot, of Dorpat, Berlin, 1826.

† Dr. Fleming first brought this notion forward in two papers published in the Edinburgh Philosoph. Journ. (April, 1829, and Jan. 1830). He adduces the case of allied species of the bear, fox, hare, and ox, living under widely different climates.

‡ Since writing the above, I have been much interested by reading an account by Professor Esmark, which proves that formerly, glaciers in Norway descended to a lower altitude than at present; and therefore, that they came down to the level of the sea in a lower latitude. This, according to generally-received ideas, would indicate a colder climate, and so it was considered to do by Professor Esmark; for he argues from it in favour of Whiston's hypothesis, that the "earth in its aphelion was covered with ice and snow." Professor Esmark describes a glacier-dike, in lat. 58° 57', as "lying close to the level of the sea, in a district, where you find only a few heaps of perpetual snow in the hollows of the mountains." He says, "Not only the dike itself, but the whole horizontal surface, exhibits proofs that there has been a glacier here, for the plain exactly resembles

[page] 295 June, 1834. ANIMALS PRESERVED IN ICE.

been shown by the imaginary case, when we transported existing phenomena from one to the other hemisphere,—the following conclusions may be deduced as probable: First, that the degree of cold formerly was not excessive; secondly, that snow did not for a long time together cover the ground (such not being the case at the extreme parts 55°-56° of S. America); thirdly, that the vegetation partook of a more tropical character than it now does in the same latitudes; and lastly, that at but a short distance to the northward of the country thus circumstanced (even not so far as where Pallas found the entire rhinoceros), the soil might be perpetually congealed: so that if the carcass of any animal should once be buried a few feet beneath the surface, it would be preserved for centuries.

Both Humboldt* and Lyell have remarked, that at the present day, the bodies of any animals, wandering beyond the line of perpetual congelation which extends as far south as 62°, if once embedded by any accident a few feet beneath the surface, would be preserved for an indefinite length of time: the same would happen with carcasses drifted by the rivers; and by such means the extinct mammalia may have been entombed. There is only one small step wanting, as it appears to me, and the whole problem would be solved with a degree of simplicity very striking, compared with the several theories first invented. From the account given by

those which I found adjoining the glaciers presently existing between Londfiord and Lomb." (See Ed. New Phil. Journal, p. 117, October 1826.) These facts afford a very strong and admirable confirmation of the view, that the climate of Europe has been gradually changing, from a character resembling that of the southern hemisphere, to its present condition. For on this hypothesis, we might have anticipated, that proofs would have been discovered, that glaciers formerly descended to a lower altitude than they now do; and yet, that the organic remains of that epoch, instead of a former period of refrigeration, would have indicated a climate of a more tropical character;—a conclusion, which may be deduced from plain geological evidence.

* See Humboldt, Fragmens Asiatiques, vol. ii., pp. 385-395.

[page] 296 TIERRA DEL FUEGO. June, 1834.

Mr. Lyell of the Siberian plains, with their innumerable fossil bones, the relics of many successive generations, there can be little doubt that the beds were accumulated either in a shallow sea, or in an estuary. From the description given in Beechey's voyage of Eschscholtz Bay, the same remark is applicable to the north-west coast of America : the formation there appears identical with the common littoral deposits* recently elevated, which I have seen on the shores of the southern part of the same continent. It seems also well established, that the Siberian remains are only exposed where the rivers intersect the plain. With this fact, and the proofs of recent elevation, the whole case appears to be precisely similar to that of the Pampas : namely, that the carcasses were formerly floated into the sea, and the remains covered up in the deposits which were then accumulating. These beds have since been elevated; and as the rivers excavate their channels the entombed skeletons are exposed.

Here then, is the difficulty: how were the carcasses preserved at the bottom of the sea? I do not think it has been sufficiently noticed, that the preservation of the animal with its flesh was an occasional event, and not directly consequent on its position far northward. Cuvier† refers to the voyage of Billing as showing that the bones of the elephant, buffalo, and rhinoceros, are nowhere so abundant as on the islands between the mouths of the Lena and Indigirska. It is even said that excepting some hills of rock, the whole is composed of sand, ice, and bones. These islands lie to the northward of the place where Adams found the mammoth with its flesh preserved, and even ten degrees north of the Wiljui, where the rhinoceros was discovered in a like condition. In the case of the bones we may suppose that the carcasses were

* See some remarks by Dr. Buckland on the similarity of this formation with the deposits so commonly found over a great part of Europe. Appendix to Beechey's Voyage, p. 609.

† Ossemens Fossiles, vol. i., p. 151.

[page] 297 June, 1834. EDIBLE FUNGUS.

drifted into a deeper sea, and there remaining at the bottom, the flesh decomposed.* But in the second and more extraordinary case, where putrefaction seems to have been arrested, the body probably was soon covered up by deposits which were then accumulating. It may be asked, whether the mud a few feet deep, at the bottom of a shallow sea which is annually frozen, has a temperature higher than 32°? It must be remembered how intense a degree of cold is required to freeze salt water; and that the mud at some depth below the surface, would have a low mean temperature, precisely in the same manner as the subsoil on the land is frozen in countries which enjoy a short but hot summer. If this be possible,† the entombment of these extinct quadru-

* Under these circumstances of slow decomposition, the surrounding deposits would probably be impregnated with much animal matter; and thus the peculiar odour perceived in the neighbourhood of the strata containing fossil bones at Eschscholtz Bay, may be accounted for. See Appendix to Beechey's Voyage.

† With respect to the possibility of even ice accumulating at the bottom of the sea, I shall only refer to the following passage taken from the English translation of the Expedition to the East Coast of Greenland, by Captain W. Graah, Danish Royal Navy. "Nor is this the only danger to be apprehended: the ice off this blink, even to a considerable distance from it, being said to shoot up from the bottom of the sea in such a manner, and in such masses, as in many years to make it utterly impassable. How to account for the phenomenon to which I have just adverted I know not, unless by supposing that the bottom of the sea itself is hereabouts like the dry land covered with a thick crust of ice. But whether this crust is formed upon the spot, or is the remains of icebergs and the heavy drift-ice frozen to the bottom during severe winters, or a portion of the land-ice, which loaded with stones and fragments of the crumbling hill has protruded itself into the sea, is a problem impossible, perhaps to solve." Again he says: "We passed it without any accident, and without having observed any thing of that upheaving of the ice off it, to which allusion has been made, though the fact of its occurrence cannot be doubted, the very name of the place, Puisortok, being thence derived." It seems fully established on excellent testimony (see Journ. of Geograph. Soc., vol. v., p. 12, and vol. vi., p. 416; also a collection of notices in Edinburgh Journal of Nat. and Geograph. Soc., vol. ii., p. 55), that freshwater rivers in Russia and Siberia, and even in England, often freeze at

[page] 298 TIERRA DEL FUEGO. June, 1834.

peds is rendered very simple; and with regard to the conditions of their former existence, the principal difficulties have, I think, already been removed.

————

Having concluded this long discussion on the analogies which may be drawn from the existing climate of the southern parts of America, together with its productions, we will return to the description of Tierra del Fuego.

There is one vegetable production in this country which is worthy of mention, as it affords a staple article of food to the aborigines. It is a globular fungus of a bright yellow colour, and of about the size of a small apple, which adheres in vast numbers to the bark of the beech-trees. It probably forms a new genus, allied to the morell. In the young state it is elastic and turgid, from being charged with moisture. The external skin is smooth, yet slightly marked with small circular pits, like those from the smallpox. When cut in two, the inside is seen to consist of a white fleshy substance, which viewed under a high power resembles, from the numerous thread-like cylinders, vermicelli. Close beneath the surface, cup-shaped balls, about one-twelfth of an inch in diameter, are arranged at regular intervals. These cups are filled with a slightly adhesive, yet elastic, colourless, quite transparent matter; and from the latter character they at first appeared empty. These little gelatinous balls could be easily detached from the surrounding mass, except at the upper extremity, where the edge divided itself into threads, which mingled with the rest of the vermicelli-like mass. The external skin directly above each of the balls is pitted, and as the fungus grows old, it is ruptured, and the gelatinous mass, which no doubt contains the sporules, is disseminated.

the bottom, and that the flakes of ice when they rise to the surface, often "bring with them large stones." All that seems to be required in producing ground-ice, is, that there should be sufficient movement in the fluid, so that the whole is cooled down to the freezing point, and then the water crystallizes, wherever there is a point of attachment.