January 15.

Changes of Climate.

An opinion has been long entertained, that there are vicissitudes in the climate and temperature of the air unknown to former times, and that such variations exist in America as well as in Europe. It is said that the transatlantic changes have been more frequent, and the heat of the sun not so early or so strongly experienced as formerly. In America, these alterations are attributed to a more obvious cause than uncertain hypothesis, and at not many degrees distance. For instance, the ice in the great river St. Lawrence, at Quebec, did not break up till the first week in May, 1817, when it floated down the stream in huge masses, and in vast quantities; these, with other masses from the coast of Labrador, &c. spread a general coldness many degrees to the southward. But a few weeks before the snow fell in some parts of New England, and New York, to a considerable cepth, and there were severe frosts. The vessels from England and Ireland, which arrived at Quebec, all concurred in their accounts of the dangers which they encountered, and the cold which they suffered. In fine, it would appear that the ice in those regions had accumulated to so alarming a degree, as to threaten a material change in all the adjacent countries, and to verify the theory of some who imagined that the extreme cold of the north was gradually making encroachments upon the extreme heat of the south. They have remarked, in confirmation of their opinions that the accounts of travellers and navigators, furnish strong reasons for supposing that the islands of ice in the higher northern latitudes, as well as the glaciers on the Alps, continue perpetually to increase in bulk. At certain times, in the ice mountains of Switzerland, there occur fissures, which show the immense thickness of the frozen matter; some of these cracks have measured three or four hundred ells deep. The great islands of ice, in the northern seas bordering upon Hudson's Bay, have been observed to be immersed one hundred fathoms beneath the surface of the sea, and to have risen a fifth or sixth part above the surface, measuring, at the same time, about a mile and a half in diameter. It has been shown by Dr. Lyster, that the marine ice contains some salt, and less air, than common ice, and that it therefore is more difficult of solution. From these premises, he endeavours to account for the perpetual augmentation of those floating islands. By a celebrated experiment of Mr. Boyle, it has been demonstrated that ice evaporates very fast, in severe frost weather, when the wind blows upon it; and as ice, in a thawing state, is known to contain six times more cold than water, at the same degree of sensible coldness, it is easy to conceive that winds sweeping over islands and continents of ice, perhaps much below nothing on Farenheit's scale, and rushing thence into our latitudes, must bring most intense degrees of cold along with them. If to this be added the quantity of cold produced by the evaporation of the water, as well as by the solution of ice, it can scarcely be doubted but that the arctic seas are the principal source of the cold of our winters, and that it is brought hither by the regions of the air blowing from the north, and which take an apparently easterly direction, by their coming to a part of the surface of the earth, which moves faster than the latitude from which they originate. Hence, the increase of the ice in the polar regions, by increasing the cold of our climate, adds, at the same time, to the bulk of the glaciers of Italy and Switzerland.

Reasonings of this kind are supported by the greatest names, and countenanced by the authentic reports of the best informed travellers. Mr. Bradley attributes the cold winds and wet weather, which sometimes happen in May and June, to the solution of ice islands accidentally detached and floating from the north. Mr. Barham, about the year 1718, in his voyage from Jamaica to England, in the beginning of June, met with some of those islands, which were involved in such a fog that the ship was in danger of striking against them. One of them measured sixty miles in length.

On the 22d of December, 1789, there was an instance of ice islands having been wafted from the southern polar regions. It was on these islands that the Guardian struck, at the commencement of her passage from the Cape of Good Hope towards Botany Bay. These islands were wrapt in darkness, about one hundred and fifty fathoms long, and above fifty fathoms above the surface of the waves. In the process of solution, a fragment from the summit of one of them broke off, and plunging into the sea caused a tremendous commotion in the water, and dense smoke all around it.

These facts were strongly urged upon public attention in the autumn of 1817,* [1] as grounds of not only curious and interesting, but likewise of highly important speculation. A supposed change in the temper, and the very character of our seasons, was deemed to have fallen within the observation of even young men, or at least middle-aged men; and upon this supposition, it was not deemed extravagant to anticipate the combined force of the naval world employed in navigating the immense masses of ice into the more southern oceans; while to render the notion more agreeable, and to enliven the minds of such as might think such matters of speculation dull or uninteresting, the project was laid before them in a versified garb, characterising the arctic regions.

There in her azure coif, and starry stole,
Grey Twilight sits, and rules the slumbering pole;
Bends the pale moon-beans round the sparkling coast,
And strews, with livid hands, eternal frost!
There, Nymphs! alight, array your dazzling powers,
With sudden march alarm the torpid hours;
On ice-built isles expand a thousand sails,
Hinge the strong helm, and catch the frozen gales;
The winged rocks to feverish climates guide,
Where fainting Zephyrs pant upon the tide;
Pass where to Ceuta Calpe's thunder roars,
And answering echoes shake the kindred shores;
Pass where with palmy plumes Canary Smiles,
And in her silver girdle binds her isles;
Onward, where Niger's dusky Naiad laves
A thousand kingdoms with prolific waves,
Or leads o'er golden sands her threefold train
In steamy channels to the fervid main,
While swarthy nations crowd the sultry coast,
Drink the fresh breeze, and hail the floating frost;
Nymphs! veil'd in mist, the melting treasures steer,
And cool with arctic snows the tropic year.
So from the burning line, by monsoons driv'n,
Clouds sail in squadrons o'er the darken'd heav'n;
Wide wastes of sand the gelid gales pervade,
And ocean cools beneath the moving shade.

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NATURALISTS' CALENDAR.

Mean Temperature   . . .   35 . 05.

Notes [all notes are Hone's unless otherwise indicated]:

1. See M. Chronicle, 4 Oct. 1817. [return]