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

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 latitudes. 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 shines brightly, but, owing to the position of the globe, obliquely on the poles. During part of that period it shines 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 latitude. 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 passing 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 shines 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 sassafras 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-passages. 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.