The Ocean and its Wonders Part 7

This question will be answered at once, and one of the phenomena of arctic ice and oceanic agency will be exhibited, by reference to the recent discoveries of the celebrated arctic voyager, Dr Kane of the American Navy.

While wintering far beyond the head of Baffin's Bay, and beyond the most northerly point, in that direction, that had at that time been reached by any previous traveller, Dr Kane made many interesting observations and discoveries. He seems to have penetrated deep into the heart of Nature's northern secrets. Among other things, he ascertained the manner in which boulders are transported from their northern home.

The slow, creeping movement of glaciers, to which we have already referred, is one means whereby large boulders are formed. At the lower edge of one of the glaciers of Norway we saw boulders, thirty or forty feet in diameter, which had been rolled and forced, probably for ages, down the valley by the glacier, and thrust out on the sea-beach, where they lay with their angles and corners rubbed off and their surfaces rounded and smoothed as completely as those of the pebbles by which they were surrounded.

Had these boulders been formed in the arctic regions, they might have been thrust out upon the thick solid crust of the frozen sea, which in time would have been broken off and floated away; thus rafting the boulders to other sh.o.r.es. The formation of boulders, and their positions, are facts that we have seen. Their being carried out to sea by ice-rafts is a fact that Dr Kane has seen and recorded. On the wild rocky sh.o.r.es where his s.h.i.+p was set fast, there was a belt of ice lining the margin of the sea, which he termed the "ice-belt," or the "ice-foot." This belt never melted completely, and was usually fast to the sh.o.r.e. In fact it was that portion of the sea-ice which was left behind each spring when the general body of ice was broken up and swept away. Referring to this, he writes:

"The spot at which we landed I have called Cape James Kent. It was a lofty headland, and the land-ice which hugged its base was covered with rocks from the cliffs above. As I looked over this ice-belt, losing itself in the far distance, and covered with its millions of tons of rubbish, greenstones, limestones, chlorite, slates, rounded and angular, ma.s.sive and ground to powder, its importance as a geological agent, in the transportation of drift, struck me with great force.

"Its whole substance was studded with these varied contributions from the sh.o.r.e; and further to the south, upon the now frozen waters of Marshall Bay, I could recognise raft after raft from the last year's ice-belt which had been caught by the winter, each one laden with its heavy freight of foreign material.

"The water torrents and thaws of summer unite with the tides in disengaging the ice-belt from the coast; but it is not uncommon for large bergs to drive against it and carry away the growths of many years. I have found ma.s.ses that had been detached in this way, floating many miles out at sea--long, symmetrical tables, two hundred feet long by eighty broad, covered with large angular rocks and boulders, and seemingly impregnated throughout with detrited matter. These rafts in Marshall Bay were so numerous, that could they have melted as I saw them, the bottom of the sea would have presented a more curious study for the geologist than the boulder-covered lines of our middle lat.i.tudes. One boulder in particular had had its origin in a valley where rounded fragments of water-washed greenstone had been poured out by the torrents and frozen into the coast-ice of the belt. The attrition of subsequent matter had truncated the great egg-shaped rock, and worn its sides into a striated face, whose scratches still indicated the line of water-flow."

So, then, when we next meet with a huge isolated boulder on any of our flat beaches, we may gaze at it with additional interest, when we reflect that, perchance, it was carried thither by the ocean, countless ages ago, from the arctic regions, on a gigantic raft of ice; after having been, at a still more remote period, torn from its cliffs by some mighty glacier and slowly rolled and rounded, for hundreds of years perhaps down the scarred slopes of its native valley.

The primary cause of the intense and prolonged cold of the arctic regions is the shortness of the time during which they are under the influence of the sun's rays. For a few months in summer the sun s.h.i.+nes brightly, but, owing to the position of the globe, obliquely on the poles. During part of that period it s.h.i.+nes at mid-night as well as at mid-day. Put during the greater part of the year its beams throw but a feeble light there, and for several months in winter there is absolutely no day at all--nothing but one long dismal night of darkness, that seems as if the bright orb of day had vanished from the heavens for ever.

The length of this prolonged day in summer, and this dreary night in winter, depends, of course, upon lat.i.tude. The length of both increases as we approach the poles. The long daylight in summer is exceedingly delightful. We once saw the sun describe an almost unbroken circle in the sky for many days and nights, and had we been a few degrees further north we should have seen it describe an entire circle. As it was, it only disappeared for twenty minutes. It set about midnight, and in twenty minutes it rose again so that there was no night, not even twilight, but a bright, beautiful blazing day, for several weeks together.

Dr Kane describes the midnight sun thus: "On our road we were favoured with a gorgeous spectacle, which hardly any excitement of peril could have made us overlook. The midnight sun came out over the northern crest of the great berg, our late `fast friend,' kindling variously-coloured fires on every part of its surface, and making the ice around us one great resplendency of gem-work--blazing carbuncles and rubies, and molten gold."

Very different indeed is the aspect of the winter night. Let the same authority speak, for he had great experience thereof.

On December 15th he writes: "We have lost the last vestige of our mid-day twilight. We cannot see print, and hardly paper. The fingers cannot be counted a foot front the eyes. Noonday and midnight are alike; and, except a vague glimmer on the sky, that seems to define the hill-outlines to the south, we have nothing to tell us that this arctic world of ours has a sun. In one week more we shall reach the midnight of the year...

"The influence of this long intense darkness was most depressing. Even our dogs, although the greater number of them were natives of the arctic circle, were unable to withstand it. Most of them died from an anomalous form of disease, to which I am satisfied, the absence of light contributed as much as extreme cold." Quoting from his journal he says: "I am so afflicted with the insomnia of this eternal night, that I rise at any time between midnight and noon. I went on deck this morning at five o'clock. It was absolutely dark; the cold not permitting a swinging lamp, there was not a glimmer came to me through the ice-crusted window-panes of the cabin. While I was feeling my way, half puzzled as to the best method of steering clear of whatever might be before me, two of my Newfoundland dogs put their cold noses against my hand, and instantly commenced the most exuberant antics of satisfaction.

It then occurred to me how very dreary and forlorn must these poor animals be, at atmospheres 10 degrees above zero in-doors and 50 degrees below zero without--living in darkness, howling at an accidental light, as if it reminded them of the moon--and with nothing, either of instinct or sensation, to tell them of the pa.s.sing hours, or to explain the long lost daylight. They shall see the lantern more frequently."

Yet this state of midnight darkness is not altogether unmitigated.

There are a few ameliorating influences at work, the nature of some of which we will treat of in the next chapter. Among others, the moon frequently s.h.i.+nes there with great brilliancy in winter. Dr Kane says that in October the moon had reached her greatest northern declination: "She is a glorious object. Sweeping around the heavens, at the lowest part of her curve she is still 14 degrees above the horizon. For eight days she has been making her circuit with nearly unvarying brightness.

It is one of those sparkling nights that bring back the memory of sleigh-bells and songs and glad communings of hearts in lands that are far away."

But despite all the varied and transient beauties of the northern skies in winter, the long arctic night is undoubtedly depressing in the extreme. In these regions men speak of being able to read the thermometer on the 7th of November at noonday "without a light," as being matter for gratulation. The darkness still before them at that time would be of about three months' duration, and even then they would only get back to a species of twilight.

The cold experienced by these navigators of the northern seas is terribly intense. Their thermometers have frequently indicated a temperature as low as 75 degrees below zero, or 107 degrees of frost, on Fahrenheit's scale. The thermometers of arctic explorers are always filled with spirits of wine, as quicksilver freezes at about 40 degrees below zero, and is therefore unsuitable. It would be frozen, indeed, the greater part of the winter.

Dr Kane says: "At such temperatures chloric ether became solid, and carefully prepared chloroform exhibited a granular pellicle on its surface. Spirits of naphtha froze at 54 degrees below zero, and oil of sa.s.safras at 49 degrees. The oil of winter-green was in a flocculent state at 56 degrees, and solid at 63 degrees.

"The exhalations from the surface of the body invested the exposed or partially clad parts with a wreath of vapour. The air had a perceptible pungency upon inspiration, but I could not perceive the painful sensation which has been spoken of by some Siberian travellers. When breathed for any length of time, it imparted a sensation of dryness to the air-pa.s.sages. I noticed that, as it were involuntarily, we all breathed guardedly, with compressed lips."

Now, strange to say, this extremely low temperature does not affect the ocean to any great depth. Just below the ice, in cold such as the above, the sea was found to be 29 degrees _above_ zero. No doubt, deeper down, the temperature was still warmer. We have heard it said, that when men chance to fall into the water in cold regions, in the depth of winter, it feels at first rather warm and agreeable! On scrambling out again, however, their condition is not enviable; for in a few minutes the keen frost causes their garments to become as hard as boards.

Much light has been thrown on the fact of the existence of under and upper currents in the sea, by the phenomena of the arctic regions, and some of the questions to which these currents give rise are so interesting that we shall treat of them in a new chapter.

CHAPTER TWELVE.

QUESTION OF AN OPEN SEA ROUND THE POLES--UPPER AND UNDER CURRENTS OF THE OCEAN--CAUSE THEREOF--HABITS OF THE WHALE AS BEARING ON THE QUESTION-- DR. KANE'S DISCOVERY OF AN OPEN SEA IN THE FAR NORTH--NOTES ON THE EXPEDITION--A BEAR-HUNT.

It was long and very naturally supposed that the impenetrable ice of the arctic regions extended to, and, as it were, sealed up the pole. But from time to time philosophic observers of Nature's laws began to hint their opinion that there is an open ocean around the pole; and of late years this opinion has all but been converted into a firm belief.

Maury remarks, that like air--like the body--the ocean _must_ have a system of circulation for its waters. And an attentive study of the currents of the sea, and a close examination of the laws which govern the movements of the waters in their channels of circulation through the ocean, will lead us irresistibly to the conclusion that always, in summer and winter, there must be, somewhere within the arctic circle, a large body of open water.

There is an under-current setting from the Atlantic, northward through Davis' Straits, into the Arctic Ocean, and a surface-current setting out.

The fact is proved beyond a doubt by the observations of arctic explorers, who have seen immense icebergs drifting rapidly northward against a strong current. This apparent anomaly could only be accounted for by the fact that a powerful undercurrent carried them northward; and as at least seven times more of these bergs must have been under than above water, we can easily understand how the under-current, acting on the larger ma.s.s of each berg, had power to carry it against the surface-current.

This under-current is _warm_, while the upper-current is _cold_. Now we know that according to Nature's laws, heated water, like heated air, rises to the surface, and cold water sinks to the bottom. How, then, comes this warm current to be underneath the cold, as soundings have proved it to be? It is owing to the fact that the under-current is much salter, and therefore heavier (despite its warmth), than the surface-current; which latter, being mingled with the drainage and ice-ma.s.ses of the arctic regions, is comparatively fresh, and therefore light as well as cold.

The hot and salt waters of the tropics are carried north by the Gulf Stream. There are here two counteracting agents at work. Heat inclines the Gulf Stream to rise; saltness inclines it to sink. During the first part of its journey, as we know, its great heat prevails over the other influence, and it flows as a surface-current. But, at a certain point in its northward route, it meets with the cold, brackish, ice-bearing currents that flow out of the arctic basin. Having lost much of its heat (though still possessing a great deal more than the arctic currents), the saltness of the Gulf Stream prevails; it dips below the polar waters, and thenceforth continues its course as an under-current, salt, and comparatively warm.

To state the matter briefly: The hot water, which _ought_ to keep on the surface because of its heat, is sunk by its superabundant salt; and the cold water, which _ought_ to sink because of its cold, is buoyed on the surface because of its want of salt.

Now arises the question--what becomes of the great quant.i.ty of salt that is thus being carried perpetually into the polar basin? Manifestly it must be carried out again by the surface-current, otherwise the polar basin would of necessity become a basin of salt. The under-current _must_, therefore, rise to the surface somewhere near the pole, with its temperature necessarily only a little, if at all, below the freezing-point--which, be it observed, is a _warm_ temperature for such regions. Here, then, where the warm waters from the south rise to the surface, it is supposed this open Arctic Ocean must exist.

So much for theory. Now for facts that have been observed, and that tend, more or less, to corroborate this proposition of an open polar sea. The habits of the whale have gone far to prove it. The log-books of whalers have for many years been carefully examined and compared by scientific men. These investigations have led to the discovery "that the tropical regions of the ocean are to the `right' whale as a sea of fire, through which he cannot pa.s.s, and into which he never enters." It has also been ascertained that the same kind of whale which is found off the sh.o.r.es of Greenland, in Baffin's Bay, etcetera, is found in the North Pacific, and about Behring's Straits; and that the `right' whale of the southern hemisphere is a different animal from that of the northern. How, then, came the Greenland whales to pa.s.s from the Greenland seas to the Pacific? Not by the Capes Horn or Good Hope; the "sea of fire" precluded that. Clearly there was ground here for concluding that they did so through the (supposed) open sea lying beyond, or rather within, the frozen ocean.

It is true the objection might be made, that the same kind of whale which exists in the North Pacific exists also in the North Atlantic, although they never cross over to see each other. But another discovery has met this objection.

It is the custom among whalers to have their harpoons marked with date and name of s.h.i.+p, and Dr Scoresby, in his work on arctic voyages mentions several instances of whales having been taken near Behring's Straits, with harpoons in them bearing the stamp of s.h.i.+ps that were known to cruise in the Greenland seas; and the dates on the harpoons were so recent as to preclude the supposition that the said whales had, after being struck, made a voyage round the capes above mentioned,--even were such a voyage possible to them. All this does not, indeed, absolutely prove the existence of an open arctic sea, but it does, we think, prove the existence of at least an _occasionally_ open sea there, for it is well known that whales cannot travel such immense distances under ice.

But the most conclusive evidence that we have in regard to this subject is the fact, that one of the members of Dr Kane's expedition, while in search of Sir John Franklin, did actually, on foot, reach what we have every reason to believe was this open sea; but not being able to get their s.h.i.+p into it, the party had no means of exploring it, or extending their investigations. The account of this discovery is so interesting, and withal so romantic, that we extract a few paragraphs relating to it from Kane's work.

After spending the dreary winter in the ice-locked and unexplored channels beyond the head of Baffin's Bay, Kane found his little s.h.i.+p still hopelessly beset in the month of June; he therefore resolved to send out a sledge-party under Morton, one of his best men, to explore the channel to the north of their position. After twelve days'

travelling they came to the base of the "Great Glacier," where Morton left his party, and, in company with an Esquimaux named Hans, set out with a dog-sledge to prosecute the journey of exploration.

They walked on the sea-ice in a line parallel with the glacier, and proceeded twenty-eight miles that day, although the snow was knee-deep and soft. At the place where they encamped a crack enabled them to measure the ice. It was seven feet five inches thick! And this in June. We may mention here, in pa.s.sing, that Dr Kane never got his vessel out of that frozen strait, which seems to be bound by perpetual ice. He and his party escaped with their lives; but the vessel that bore them thither is probably still embedded in that ice.

Next day Morton and Hans came to a region of icebergs, which had arrested a previous sledging-party of the same expedition. "These [icebergs] were generally very high, evidently newly separated from the glacier. Their surfaces were fresh and gla.s.sy, and not like those generally met with in Baffin's Bay,--less worn, and bluer, and looking in all respects like the face of the Great Glacier. Many were rectangular, some of them regular squares, a quarter of a mile each way; others more than a mile long."

To pa.s.s amidst these bergs was a matter of labour, difficulty, and danger. Sometimes the sides of them came so close together, that the men could scarcely squeeze between them, and they were obliged to search for other pa.s.sages; in doing which, the variation of their compa.s.s confused them. At other times, "a tolerably wide pa.s.sage would appear between two bergs, which they would gladly follow; then a narrower one; then no opening in front, but one to the side. Following that a little distance, a blank ice-cliff would close the way altogether, and they were forced to retrace their steps and begin again."

Thus they puzzled their way through, "like a blind man in the streets of a strange city;" but more difficulties awaited them beyond. After advancing many miles they were arrested by broad rents in the ice, and were obliged to diverge frequently far out of their course, or to bridge the chasms over by cutting down the ice hummocks and filling them up with loose ice, until the dogs were able to haul the provision-sledge over.

Advancing thus for several days, and encamping on the snow at night, they at last came to a spot where the ice was dangerous. "It was weak and rotten, and the dogs began to tremble." Proceeding at a brisk rate, they had got upon unsafe ice before they were aware of it. Their course was at the time nearly up the middle of the channel; but as soon as possible they turned, and by a backward circuit reached the sh.o.r.e. The dogs, as their fas.h.i.+on is, at first lay down and refused to proceed, trembling violently. The only way to induce the terrified, obstinate brutes to get on, was for Hans to go to a white-looking spot, where the ice was thicker, the soft stuff looking dark; then calling the dogs coaxingly by name, they would crawl to him on their bellies. So they retreated from place to place, until they reached the firm ice they had quitted. A half mile brought them to comparatively safe ice, a mile more to good ice again.

In the midst of this danger they had, during the liftings of the fog, sighted open water. Soon after they saw it plainly. So many long and dreary months had these men pa.s.sed since they were gladdened by the sight of open water, that they could scarcely believe their eyes; and Morton declared, that but for the birds which were seen flying about it in great numbers, he would not have believed it.

They made for the land-ice as fast as possible, and quickly gained it; but the sea-ice had cracked off and sunk so much, that the land-ice presented a wall along the whole coast of about eight or nine feet high.

It was quite perpendicular, in some places overhanging, so that it was a matter of the greatest difficulty they managed to throw up the provisions, clamber up themselves, and haul the dogs and sledge up afterwards. This accomplished, however, they were safe, and could advance with confidence. But this ma.s.s of land-ice became narrower as they proceeded, till at last it dwindled to a mere narrow ledge, clinging to the high, perpendicular cliffs, and looking as if at any moment it might crumble off and fall with them into the open water between it and the floating sea-ice.

The sea here was very deep and clear. They could see the bottom quite plainly, although a stone they cast in, the size of a man's head, took twenty-eight seconds to reach it.

Being now afraid of the ice-ledge, they attempted to find a path along the face of the cliff; but failing in this, Morton determined to leave part of the provisions in "_cache_," and proceed with a lighter load.

The cape round which they were travelling, and on the other side of which lay the open water, was extremely bold, and the ice-ledge at the end of it was barely three feet wide; so they were obliged to unloose the dogs, and drive them forward alone, then tilted the sledge on one runner, and thus pushed it past the worst place.

Here the ice on the sea was partly broken up, and a strong tide was running from the southward. The night before it had been running from the north. As they advanced, the channel became still more open, and after pa.s.sing the cape they saw nothing but open water, with innumerable wild sea-birds of every description flying overhead, or disporting in the pools. Let it by observed here, however, that this was the open water of a strait or channel,--not the great Arctic Sea, about the probable existence of which we have been writing. Upon the ice-ma.s.ses near them numerous seals were seen basking.