ENCOUNTER WITH ICEBERGS.
AN ARCTIC SCENE.
Whence come these mighty masses? They are discharged from the frozen rivers of the North, the great glaciers that line the west coast of Greenland and the shores of Iceland. The constant snows of the arctic regions falling on the mountains and drifting into the valleys, solidify into mighty glaciers which, pent in by the rocky hills, come sweeping through the winding valleys to the sea. Great as are the glaciers of the Alps, they are but pigmies compared with those of Greenland. The Tyndall glacier where it discharges into the sea is two miles in width;—but grand above all is the great Humboldt glacier, whose lofty face reaches three hundred feet above the sea level and beneath it to an unknown depth, while it is over sixty miles in width. Slowly but steadily this whole mass is pushed forward. The angle at which it descends from the hills soon forces under the water a greater part of the ice than would be submerged were it floating unattached, and the natural buoyancy of the ice causes it to break loose with a thundering report. Splashing and plunging, it finally rights itself and goes majestically sailing on borne by the currents, till melted by the warmer waters of the Atlantic it finally disappears entirely.
The amount of snow that falls upon the arctic lands is unknown. It is no doubt very great. In the Swiss Alps in a single night it has fallen to the depth of six and a half feet. At the Hospice of Grimsel, Agassiz noted in six months a fall of fifty-seven and a half feet. If we suppose that no more than this falls on the mountains of Greenland, we should have an annual deposit of one hundred and fifteen feet. Now every cubic yard of snow weighs one hundred and eighty-seven pounds, so that the lower strata would have upon it a pressure of over three tons, a weight sufficient to change the snow at once to solid ice. This change into ice by pressure can be noticed on a small scale by any one who walks abroad after a slight fall of snow. On ceasing to walk, the bottom of the boot will be found to be covered with a thin layer of ice.
