Графични страници
PDF файл

vate gardens. From this we ascended to the greatest height, Pico del Pozo de las Nieves, 5842 feet high: but our expectation of surveying the whole island was not fulfilled. During the whole day, the atmosphere was loaded with very dense vapour, which was not aqueous, but which, on all sides, obstructed our vision. The nearest valleys were scarcely discernible, and the sea-coast was perfectly invisible. The summit itself was not much involved. It is a plain covered with small stones, with no plants upon it. The beautiful Peucedanum aureum is the only plant upon the height to reward the botanist for the labour of climbing. On the contrary, S. Matheo, which commenced near the top, welcomed us in a very pleasing and friendly manner. For, in the midst of rushing waters, there are tall broad leaved chesnut and nut trees; and fruit trees of every kind are scattered over the green fields in great abundance. In Lecheguillo, the first place in the valley, and yet 3103 feet high, the inhabitants met us in a very friendly manner. Their habitations, surrounded with large galleries, and lying scattered on the declivity, had quite a pastoral appearance, and the houses round the church of S. Matheo were charmingly situated. We then come to the vineyards and the villas of the inhabitants of Palmas. The Vega de Sta Brigita, down to the scorching and violent heat of the inferior region, permits the growth of nothing but prickly small leaved shrubs.

(To be continued.)

Observations on the Arctic Sea and Ice, and the intended Expedition of Captain Parry to the North Pole. By THOMAS LATTA, M. D. (Communicated by the Author.)

IN earlier ages, when science was in its infancy, very erroneous opinions were entertained, in regard to the nature of our globe. It is scarce 300 years since its spherical shape was acknowledged; and, prior to that period, a very considerable proportion of it was deemed uninhabitable; for, those countries situated under the Line, were considered an arid waste, burnt up by the fiery beams of a tropical sun, whilst it was supposed that far to the north lay regions of eternal frost, entirely destitute of organization. But these errors have disappeared with

[merged small][ocr errors][merged small]

the progress of science, and the bright career of discovery has made us acquainted with almost the whole of the terraqueous globe. The only regions which, from their physical peculiarities, have hitherto resisted our attempts, are those immediately surrounding the Poles; for the Antarctic Regions, notwithstanding the exertions of Cook, Billinghausen and Weddell, are but little known; and the Arctic Regions, although the investigation of their nature has engaged the enterprise of Europe for a long series, of years, have not been explored beyond the 80° of latitude. Already upwards of forty expeditions have failed in exploring a North-West Passage into the Pacific; and the last navigator, after repeated failures, has, for the present, relinquished the enterprise, although convinced of the existence of the disputed passage. Comparatively few attempts have been made to sail directly towards the Pole, or through the North Eastern Seas to India; and the expeditions in these directions have been so inefficient, that an almost untrodden field of discovery remains for the mariner.

The chief obstacle to the progress of discovery in the Frigid Zone, is the vast accumulation of ice which floats on the surface of the ocean, rendering all the efforts of navigation abortive. To overcome this opposition, a novel method has been suggested, the merits of which are to be tried during the approaching summer, by a party under the command of Captain Parry, in an attempt to reach the North Pole. They are to be conveyed to the north western extremity of Spitzbergen, in the Hecla, and from thence are to set out in boats made of light materials, so constructed that they may be converted into sledges, thus suited to the nature of the tract, whether it be water or ice. With these slender means, our brave navigators will endeavour to unfold the secrets of the Pole. The skill and daring they have already shewn, prove that they are worthy of the confidence reposed in them. Whilst they were employed on their former hazardous voyages, we felt solicitous about their welfare, and were not sanguine of success; we cannot but harbour unpropitious auguries, when we glance at the scene of their future toils, which, though holding out a fairer prospect of success, is nevertheless pregnant with peril. The enterprise is so striking in its nature, that we, who have personally visited the

Arctic Regions, presume to lay before the public at this time a few observations.

In these it is intended, first, to delineate the general effects of the different seasons, on the Arctic Sea; and, from the phenomena which occur in those parts, which are familiar to us, to form a few conjectures in regard to what may be the condition of the unexplored regions, north and east from Spitzbergen; and, secondly, To consider the possibility of exploring these.

Probable State of the Globe at the Pole.-It may be premised, that an erroneous opinion has long been cherished,that the vicinity of land is necessary, ere ice can be formed on the sea, an opinion which seems still to bias the minds of a few, notwithstanding the incontrovertible evidence of men of science, who have spent almost half their lives in the inhospitable regions of the polar seas. On this groundless opinion some ingenious speculations have been framed, the purport of which was, to demonstrate, that, if the Hyperborean Regions are covered with water, that this sea must be navigable; for, there being no sheltering shores to aid the formation of ice, it must be but sparingly produced, and easily dissipated. by the warmth of a nightless summer. Although we are satisfied that such a conclusion is erroneous, it cannot be denied that windward islands, mural coasts, or sheltering promontories, may facilitate the freezing process; yet undoubtedly the wide ocean, with all its disadvantages, may, under the rigours of a long winter, receive its firm covering of ice, No doubt, preparation for such an event is requisite, for the effects of many arctic winters would be required to reduce the temperature of such an immense body of water sufficiently, to admit of its surface being frozen; an event which, if the present motions in the ocean existed from the beginning, must have been much procrastinated, as the perpetual efflux of cold water from the north is replaced by streams of higher temperature from southern seas. It is probable, however, that the extent of these interchanges are much circumscribed, and that the water of the Pole is beyond their limits, a conclusion authorised by their apparent course and magnitude for, the water which runs through Behring's Strait into the Frozen Ocean, and that which constitutes the nor

thern branch of the Gulph Stream, which passes towards Greenland, along the coast of Norway, together with the produce of rivers, and melting ice and snow, replaces what is carried off by the broad stream which flows westward through the Siberian Sea, by the coast of Old Greenland, into the Atlantic, and, by the current which runs southward, through Davis' Straits. Now, if we find that the surface of the sea, in the course of these outflowings, is annually frozen over, surely in circumpolar latitude it must be more completely so; for, in the former, the temperature must be influenced by the water which comes from warmer seas; whereas the latter is far beyond its reach. Then, if it is the case that there are no currents of importance, either coming from the Pole, or flowing towards it, the whole of this currentless sea, if sea it is, must be covered with immoveable ice.

The influence of the various agents which every season destroy the ice in the accessible regions of the Greenland Seas, is very widely extended; but far towards the north, it may be so inconsiderable, that the ice may remain solid, thus precluding the possibility of reaching the Pole through a navigable sea.

Summer and winter are the only seasons that occur in Greenland. The former possesses none of those charms so congenial to sense in happier climes; and the latter is clad in tenfold terrors. At the close of the year the frost, which a summer solstice scarce can soften, sets in with terrible violence, and scatters thick the icy particles on the face of the deep, which counteract the efforts of the rudest tempest, smooth down the billows, and prepare a quiet surface for their coalescence. A continued augmentation takes place, scale with scale coheres; mass becomes glued to mass; and field to field; till the dark waters of the ocean are buried under an interminable wilderness, stretching from the dark regions of the north far to the south, till arrested by a latitude which, though almost too cold for the habitation of man, is too mild for the formation of these gelid productions.

The line of arrestment extends from the coast of Labrador, by Cape Farewell and Iceland, and after retiring to form a deep bay, about the 7° or 8° of eastern longitude, it stretches across to Nova Zembla, and is much modified by temperature and prevailing winds.

On the approach of spring the seaward limits of this mighty frozen plain are broken up, and the fragments are gradually dissolved, as they are carried by the currents down the Atlantic. Thousands of square leagues disappear in the course of a few weeks, a free course is opened to the fishermen, even to the northern shores of Spitzbergen; and, as the season advances, the same process evidently goes on to a certain extent, in the unexplored North Eastern Seas. Their fields, too, are destroyed, and the ruins, borne past Nova Zembla, disappear in their drift to the southward.

Thus, the reign of winter in these forlorn regions is relaxed by the returning sun, and the slumbering deep roused by the storm, rends in fragments the frozen loads, dashes mass on mass, and hurls the whole to ruin. On the shores of Spitzbergen a thawing temperature prevails during the summer, and the flowerets on the warm bank, disburdened of its snowy cover, flourish for a time, whilst the inland country, buried under the snow of ages, is scarcely visited by a thawing beam.

It is by reasoning on the causes of this mighty havoc, and contemplating the effects produced by them, that conjectures on the state of the untraversed seas, north and east from Spitzbergen, have been conceived.

The chief agents in destroying the ice seem to be, the Sun's rays, the tempest, the currents, attrition, and the wind-lipper. Action of the Sun's Rays.-The sun's rays exert a double influence; 1st, By expansion: and, 2dly, By solution.

The effects of expansion are of the first magnitude. But for this, the ice of the north, having acquired its usual thickness, might bid defiance to the efforts of every other agent, and remain almost immoveably the same. The storm may break up the detached fields; attrition may comminute their fragments, the wind-lipper may wash them out of existence: or the currents may carry them into other seas; but until the frozen continent is broken up, and reduced to fields, all these can make but little impression.

Authors have published accounts of the various forms which the ice of Greenland assumes, and have theorized on their mode of formation; but concerning the detachment of fields, they have all been silent, so far as I know. This very important process

« ПредишнаНапред »