The Ocean and Its Wonders by R. M. Ballantyne (ebook reader with built in dictionary txt) 📕

It is well known that when fresh water becomes so cold that its temperature is 32 degrees of Fahrenheit’s scale, it loses its liquid form and becomes ice. A somewhat lower temperature than this is necessary to freeze salt water; the reason being, that greater force is required to expel the salt which the sea holds in solution,—which salt is always more or less expelled in the process of freezing.

Ice commences to form in the shape of needles, which shoot out at angles from each other. In smooth water, under the influence of intense cold, the process is rapid, and a thin cake soon covers the water, and increases in thickness hour by hour. But when the sea is agitated the process is retarded, and the fine needles are broken up into what arctic navigators call sludge. This, however, soon begins to cake, and is broken by the swell into small cakes; which, as they thicken, again unite, and are again broken up into larger masses. These masses, by rubbing against each other, have their edges slightly rounded up, and in this form receive the name of pancake ice.

When a quantity of ice covers the ocean in a wide level sheet of considerable extent, it is called an ice-field. Fields of this kind are often seen by navigators hundreds of miles in extent, and nearly thirty feet thick. Ice of such thickness, however, only shows five or six feet above water. When fields are broken by heavy ocean-swells, the edges are violently forced up, and fall in débris on the surface; thus hummocks or mounds are formed.

When field-ice breaks up under the influence of an ocean-swell, caused by a storm, the results are terrific.

An exceedingly graphic account of an incident of this kind is given by Dr Brown, in his “History of the Propagation of Christianity.” He writes:—

“The missionaries met a sledge with Esquimaux, turning in from the sea, who threw out some hints that it might be as well for them to return. After some time, their own Esquimaux hinted that there was a ground-swell under the ice. It was then scarcely perceptible, except on lying down and applying the ear close to the ice, when a hollow, disagreeable, grating sound was heard ascending from the abyss. As the motion of the sea under the ice had grown more perceptible, they became alarmed, and began to think it prudent to keep close to the shore. The ice also had fissures in many places, some of which formed chasms of one or two feet; but as these are not uncommon in ice even in its best state, and the dogs easily leap over them, they are frightful only to strangers.

“As the wind rose to a storm, the swell had now increased so much that its effects on the ice were extraordinary, and really alarming. The sledges, instead of gliding smoothly along as on an even surface, sometimes ran with violence after the dogs, and sometimes seemed with difficulty to ascend a rising hill. Noises, too, like the report of cannon, were now distinctly heard in many directions, from the bursting of the ice at a distance. Alarmed at these frightful phenomena, our travellers drove with all haste towards the shore; and, as they approached it, the prospect before them was tremendous. The ice having burst loose from the rocks, was tossed to and fro, and broken in a thousand pieces against the precipices with a dreadful noise; which, added to the raging of the sea, the roaring of the wind, and the driving of the snow, so overpowered them as almost completely to deprive them of the use of their eyes and ears.

“To make the land was now the only resource that remained, but it was with the utmost difficulty that the frightened dogs could be driven forward; and as the whole body of the ice frequently sank below the summits of the rocks, and then rose above them, the only time for landing was the moment it gained the level of the coast—a circumstance which rendered the attempt extremely nice and hazardous.

“Both sledges, however, succeeded in gaining the shore, and were drawn up off the beach, though not without great difficulty. Scarcely had they reached it, when that part of the ice from which they had just escaped burst asunder, and the water, rushing up from beneath, instantly precipitated it into the ocean. In a moment, as if by a signal, the whole mass of ice for several miles along the coast, and extending as far as the eye could reach, began to break up, and to be overwhelmed by the waves. The spectacle was awfully grand. The immense fields of ice rising out of the ocean clashing against each other, and then plunging into the deep with a violence which no language can describe, and with a noise like the discharge of a thousand cannon, was a sight which must have filled the most unreflecting mind with feelings of solemnity.

“The Brethren were overwhelmed with amazement at their miraculous escape, and even the Esquimaux expressed gratitude to God for their deliverance.”

Such is the terrible aspect in which field-ice is seen when broken up and converted into smaller masses or floes. When these lie closely together the mass is called pack-ice; in which shape it usually drifts away with the southern currents, and, separating as it travels south, is met with in loose floating masses, of every fantastic form. There is always, as we have said, a large quantity of floe and pack-ice in the polar seas, which becomes incorporated with the new ice of the succeeding winter; and not infrequently whale and discovery ships get frozen into the pack, and remain there as firmly embedded as if they lay high and dry on land. When the pack is thus re-frozen, it usually remains stationary; but there are occasions and circumstances in which the entire body of a pack drifts slowly southward even during the whole year; showing clearly that oceanic circulation is by no means arrested by the icy hand of the hyperborean winter.

A very remarkable drift of this kind is recorded by Captain McClintock of the Fox, which is worthy of being noticed here, as illustrative of the subject we are now considering and also as showing in a remarkable manner the awful dangers to which navigators may be exposed by the disruption of the pack in spring, and the wonderful, almost miraculous, manner in which they are delivered from imminent destruction.

In attempting to cross Baffin’s Bay, by penetrating what is called the “middle ice,” the Fox was beset, and finally frozen in for the winter; and here, although their voyage may be said to have just commenced, they were destined to spend many months in helpless inactivity and comparative peril and privation. Their little vessel lay in the centre of a field of ice of immense extent; so large, indeed, that they could not venture to undertake a journey to ascertain its limits. Yet this field slowly and steadily descended Baffin’s Bay during the whole winter, and passed over no fewer than 1385 statute miles in the space of 242 days, during which period the Fox was firmly embedded in it!

It is with difficulty the mind can form any adequate conception of the position of those voyagers;—unable to move from their icy bed, yet constantly drifting over miles and miles of ocean; uncertain as to the where or the when of their deliverance from the pack; exposed to the terrible dangers of disrupting ice, and surrounded by the depressing gloom of the long arctic night.

At length deliverance came; but it came surrounded by terrors. In February, McClintock writes thus: “Daylight reveals to us evidences of vast ice-movements having taken place during the dark months, when we fancied all was still and quiet; and we now see how greatly we have been favoured, what innumerable chances of destruction we have unconsciously escaped. A few days ago, the ice suddenly cracked within ten yards