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GREENLAND.

BY WILLIAM PENGELLY, F.R.S., F.G.S.

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NEOGRAPHERS and geologists have for some time devoted U a large amount of attention and labour to Greenland ; and, judging from the numerous reports and papers on it, which have been read to various scientific bodies, it must be admitted that their efforts have been crowned with great success. Of these communications, those which have most recently arrested our attention are Professor Heer's “ Contributions to the Fossil Flora of North Greenland," read to the Royal Society of London on March 11, 1869,* and Dr. Brown's 6 Physics of Arctic Ice," read to the Geological Society of London on June 22, 1870,f the latter treating of the country as it is at present, and the former of its condition during the Miocene period of the geologist.

From time to time, Arctic voyagers—especially McClintock, Inglefield, Colomb, and Olrick--have brought from Greenland considerable collections of fossil plants, which have been lodged in the museums of London, Dublin, and Copenhagen. They have attracted so much attention, and their revelations have been so startling, as to induce the Royal Society of London and the British Association to vote, in 1866, liberal grants of money for the purpose of investigating the fossiliferous beds, and making as complete a collection as possible of the remains of the plants which they contain. The expedition was entrusted to Mr. E. Whymper, so well known for his Alpine researches, and Dr. Brown, who had previously travelled in Arctic North America, Greenland, and Spitzbergen, and had availed himself of the ample opportunities he had thus enjoyed for studying ice phenomena.

They reached the colony of Jacobshavn, in Greenland, on June 16, 1867, and left the island on the 10th of the following September, having received, during their stay, every assistance

* See "Phil. Trans." for 1869, Pt. II. pp. 445-488. † See “ Quart. Journ. Geol. Soc." vol. xxvi. pp. 671-701.

from the Danish authorities. The fossils they brought home were submitted to Professor Heer, the eminent botanist of Zurich, whose report on them has already been named.

Greenland is in all likelihood a large wedge-shaped island, covered everywhere in the interior with a sheet of ice of unknown depth. The coast-line surrounding this vast mer de glace is of variable breadth, and has the aspect of a circlet of bare bleak islands rising to the height of about two thousand feet, and separated by deep inlets or fjords, which are the channels through which the overflow of the interior ice finds its way to the sea. During the short Arctic summer the snow clears off this outskirting land, on which the population of Greenland lives and the Danish trading-ports are built.

Though a familiar subject of conversation among the colonists from the earliest times, very few of them have ever visited the great interior sea of ice; whilst the natives have a great horror of it, not only because of the dangers it presents, but from a belief that it is inhabited by evil spirits of monstrous forms. At the inlets, where the interior ice sometimes reaches the sea, it presents “ice-walls,' varying in height from one thousand to three thousand feet, according to the depth of the valley. This wall is always steep, because bergs are continually breaking off from it, thus rendering approach to it very dangerous, on account, not only of the falling ice, but of the waves which it produces. One of these faces, known as Humboldt's Glacier, is about sixty miles broad.

Once fairly on the ice in the interior, a dreary scene meets the view—one great ice-field, unbroken in all directions, except in those in which the outskirting land is seen. The traveller, however, finds it traversed with crevasses, the bottom of which he is unable to see, or to reach with his sounding-line. The surface of the field rises continuously but gently, the gradient diminishing towards the interior. In the winter it must be covered with a deep layer of snow, and the surface must be smooth as a glassy lake; but in the summer this covering is converted into water, which, in the form of streams, finds its way to the sea, directly by flowing on the surface to the edge, or indirectly by falling into the crevasses, and thence by subglacial routes. As is the case with glaciers generally, the surface of the ice is ridged and furrowed; and so far as observations have gone, this increases towards the interior. Nowhere is there to be seen on it a trace of any living thing, or a patch of earth, or a stone, or, in short, anything whatever to remind one of the outer world. An afternoon breeze blows over it regu. larly with such piercing bitterness, that the explorers found their Eskimo dogs crouched under the lee of the sledge for shelter.

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There seems every probability that the country is covered with one continuous almost level field of ice, concealing or obliterating all indications of hill and valley, without a single break, for upwards of twelve hundred miles from north to south, and four hundred from east to west. Its thickness is unknown; but when it is remembered that every square mile contains six hundred and forty acres, that the weight of an inch of rain is upwards of one hundred tons per acre, and that, even exclusive of the pressure, the specific gravity of ice is about eight-ninths of that of water, it will be seen that the unbroken ice-field of Greenland must have an area of upwards of three hundred million acres, and a weight of more than twenty-seven thousand million tons for every inch of its thickness.

From the facts that ice-bergs are rare on the east coast, and that no stones or other indications of land are found on the surface of the ice-field, it is thought probable that there is no high land in the interior, but that the ice slopes continuously from east to west; and as the surface of the vast accumulation of ice in the known interior, so far from anywhere attaining the height of the circumscribing land, can only be seen by climbing to considerable elevations on the latter, it is believed by Dr. Brown that the bare surface of the country, were its glacial covering removed, would resemble a huge shallow vessel with high walls around it—a vessel now filled with ice, whick slowly flows off, in the form of glaciers, through the enormous lips in the zone of mountain-land forming its rim. Dr. Brown is of opinion that a great inlet once stretched across the island from Jakobshavn ice-fjord, as represented on the old maps, but that it is now choked up with consolidated bergs.

It can scarcely be doubted that, in the course of ages, the glaciers, slowly travelling seaward, grind down the bottoms of the valleys to the sea-level, and thus convert the valleys themselves into fjords, such as are so prevalent on the coasts of northern countries in general. When a glacier reaches the sea, it grooves its way along the submarine bottom for a considerable distance-in some instances upwards of a mile-until it is stopped by the buoying action of the water, through which, and not the force of gravity, a portion is ultimately broken off and an ice-berg is formed. “ The ice,” says Dr. Brown, “ groans and creaks, then there is a crashing, then a roar like the discharge of a park of artillery, and with a monstrous regurgitation of waves, felt far from the scene of disturbance, the ice-berg is launched into life.” Some of the bergs may be seen sailing majestically in long lines out of the ice-fjords, to be wafted in various directions by the winds and currents. Some of them ground near the fjords, where they remain for months or even years, and are only removed by 6 calving," or pieces breaking off from them.

Dr. H. Rink, of Copenhagen, whose long residence in the country entitles his opinion to the greatest respect, has calculated the yearly precipitation, including both snow and rain, at ten inches, and the discharge of ice, in the form of glaciers, at two inches. A small portion is given off by evaporation, but the greatest discharge is probably in the streams of water which pour out beneath the glaciers, both in summer and winter. We do not appear to be in possession of sufficient data to justify an opinion as to how far the united yearly discharge of ice, water, and vapour at present equals the annual precipitation. It is obvious that the question of the increase or decrease of the existing ice-sheet hinges on this point.

The sub-glacial streams, thickly loaded with mud from the grinding of the glaciers on the rocks over which they travel, discolour the sea for miles, and finally deposit on the bottom a thick coating of the finest material, in which Arctic marine animals burrow in great numbers. Some of the inlets, formerly quite open for boats, are now so choked up with bergs

—mainly, it is thought, in consequence of the deposits of subglacial mud—that going up them is never thought of at present.

Occasionally, without a breath of wind stirring, ice-bergs are seen “ shooting out ” of an inlet, propelled, in all probability, by the waves produced by a fresh berg being detached from the glacier up the fjord.

The bergs when aground have always a slight movement, which stirs up the food on which the seals largely subsist; hence the neighbourhood of such bergs is a favourite haunt of these animals, and thus too often tempts the native fisherman, who not unfrequently loses his life by falling ice. 6 When we would row between two bergs," says Dr. Brown, “to avoid a few hundred yards' circuit, the rowers would pull with muffled oars and bated breath. Orders would be given in whispers, and even were Sabine's gull or the great auk to swim past, I scarcely think that even the chance of gaining such a prize would tempt us to run the risk of firing, and thereby endangering our lives by the reverberations bringing down pieces of crumbling ice hanging overhead. A few strokes and we are out of danger; and then the pent-up feelings of our stolid fur-clad oarsmen find vent in lusty huzzahs! Yet, when viewed out of danger, this noble assemblage of ice palaces, hundreds in number being seen at such times from the end of Jakobshavn Kirke, was a magnificent sight; and the voyager might well indulge in some poetic frenzy at the view. The noonday heat had melted their sides; and the rays of the red evening sun glancing askance among them would conjure up fairy visions of castles of silver and cathedrals of gold. . . Suddenly there is a swaying, a moving of the water, and our fairy palace falls in pieces, or, with an echo like a prolonged thunderclap, it capsizes, sending the waves in breakers up to our very feet.”

Ordinary Alpine glaciers, like those of Switzerland, flowing down mountain gorges, receive great accumulations of rocky débris on each side, which are termed lateral moraines. In the frequent case of two such gorges uniting in one at a lower level, what may be called the adjacent or inner laterals become one, and form a medial moraine. Not unfrequently portions of the material thus accumulated on the surface fall through the crevasses, and, reaching the bottom, participate there in the general downward motion, and with the débris the glacier has dislodged from the rocky surface on which it travels, form the moraine profonde or basal moraine. If, as in the Alps, the glacier terminates without reaching the sea, most of the matter thus transported is deposited at its foot, and forms a terminal moraine.

The glaciers of Greenland are much more simple. They bring no débris from the interior; and the short valleys through which they reach the sea rarely unite. The surface material—which is inconsiderable, and seldom takes the form of a medial moraine—together with that at the base, is floated off by the detached bergs, which not unfrequently capsize in the inlets, and thus deposit, at least, the greater part of their burthen before reaching the open sea. Hence, could the submarine surface be inspected, it would in all probability be found to consist of tenacious clay, imbedding a long line of boulders, shells, and bones of seals and other marine animals. This matter must frequently be re-arranged by the enormous momentum of ice-bergs grounding on it. Dr. Brown mentions the case of a berg which, in 1867, he observed at the mouth of the Waygatz, carrying a block of rock that, even at a distance, looked as large as a good-sized house.

Greenland, though so intensely cold, and apparently so cheerless, is full of interest to the naturalist, and by no means without profit for the merchant. The outskirting land sufports a luxuriant growth of from 300 to 400 species of plants, some of which ascend to the height of 4,000 feet; many species of seals, and whales, and fish sport in the waters, which are also occupied by invertebrate animals and seaweeds; every rock swarms with water-fowl, whilst land-birds from the south visit the country as a nesting-place; countless herds of reindeer browse in some of its valleys; the bark of the fox is to be heard even in the depth of winter; and the polar

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