DIMENSIONS OF AN ICE FIELD.
In order fully to appreciate the power and magnitude of this ice-movement, it must be borne in mind that a very large proportion of the ice is of very ancient formation,—old floes or ice-fields of immense thickness and miles in extent, as well as of icebergs discharged from Humboldt Glacier. These vast masses, tearing along with the current in the early winter through the sea as it is closing up and new ice is making rapidly, are as irresistible as a tornado among the autumn leaves. As an illustration, I will give the dimensions of an old field measured by me while crossing the Sound. Its average height was twenty feet above the sea level, and about six by four miles in extent of surface, which was very uneven, rising into rounded hillocks as much as eighty feet in height, and sinking into deep and tortuous valleys.
To cross such a floe with our sledges was almost as difficult as crossing the hummocks themselves; for, in addition to its uneven surface, like that of a very rough and broken country, it was covered with crusted snow through which the sledge-runners cut continually, and which broke down under the foot. I estimated its solid contents, in round numbers, at 6,000,000,000 of tons, its depth being about one hundred and sixty feet. Around its border was thrown up on all sides a sort of mountain chain of last year's ice, the loftiest pinnacle of which was one hundred and twenty feet above the level of the sea. This ice-hill, as it might well be called, was made up of blocks of ice of every shape and of various sizes, piled one upon the other in the greatest confusion. Numerous forms equally rugged, though not so lofty, rose from the same ridge, and from every part of this desolate area; and if a thousand Lisbons were crowded together and tumbled to pieces by the shock of an earthquake, the scene could hardly be more rugged, nor to cross the ruins a severer task.
ORIGIN OF A FLOE.
The origin of such a floe dates back to a very remote period. That it was cradled in some deep recess of the land, and there remained until it had grown to such a thickness that no summer's sun or water's washing could wholly obliterate it before the winter cold came again, is most probable. After this it grows as the glacier grows, from above, and is, like the glacier, wholly composed of fresh ice,—that is, of frozen snow. It will be thus seen that the accumulation of ice upon the mountain tops is not different from the accumulation which takes place upon these floating fields, and each recurring year marks an addition to their depth. Vast as they are to the sight, and dwarfs as they are compared with the inland mer de glace, yet they are, in all that concerns their growth, truly glaciers—pigmy floating glaciers. That they can only grow to such great depth in this manner will be at once apparent, when it is borne in mind that ice soon reaches a maximum thickness by direct freezing, and that its growth is arrested by a natural law.
AVERAGE THICKNESS OF THE ICE.
This thickness is of course dependent upon the temperature of the locality; but the ice is itself the sea's protection. The cold air cannot soak away the warmth of the water through more than a certain thickness of ice, and to that thickness there comes a limit long before the winter has reached its end. The depth of ice formed on the first night is greater than on the second; the second greater than the third; the third greater than the fourth; and so on as the increase approaches nothing. The thickness of ice formed at Port Foulke was nine feet; and, although the coldest weather came in March, yet its depth was not increased more than two inches after the middle of February. In situations of greater cold, and where the current has less influence than at Port Foulke, the depth of the table will of course become greater. I have never seen an ice-table formed by direct freezing that exceeded eighteen feet. But for this all-wise provision of the Deity, the Arctic waters would, ages ago, have been solid seas of ice to their profoundest depths.
The reader will, I trust, bear patiently with this long digression; but I thought it necessary, in order that he might have a clear understanding as well of our situation as of the character of these Arctic seas; in which I shall hope that I have inspired some interest. As for ourselves, we were struggling along through this apparently impassable labyrinth, striving to reach the coast which now began to loom up boldly before us, and thence stretching away into the unknown North, there receives the lashings of the Polar Sea.
SLOW PROGRESS.
To come back to the narrative which we abandoned so suddenly. The 24th of April found us on the margin of the very floe which I have been describing, weary, worn, and much dispirited. Since we broke camp at Cairn Point, we had made in a direct line from that place not over thirty miles. The number of miles actually traveled could not be easily estimated; but it was scarcely less than five times that distance, counting all our various twistings and turnings and goings and comings upon our track. But I propose again to let my diary speak for itself; and, as on a former occasion, when the evil genius of that unhappy manuscript led it into type, we will resort to a new chapter.