Blackwood's Edinburgh Magazine, Volume 65, No. 402, April, 1849. VariousЧитать онлайн книгу.
of mountains.
An interesting note on this subject says, "It appears probable, that a legitimate way is now opening towards the solution of the ultimate problem of the upheaving force. The agreement of deductions from the scientific hypothesis goes far to establish, that all dislocations of strata, and the accompanying mountain chains, have resulted from the upheaval of large portions of the earth's surface by a diffused and equable energy – an energy concentrated in one point or district, only when it has produced craters of elevation. Accepting instruction from the surface of the moon, we have certain lights also respecting the history of the development of this force; for, while its concentrated action, with its varied and remarkable craters, has evolved nearly all the mountain forms in that luminary, even as we find it among the almost obliterated ancient forms of the earth, its operation in raising extensive zones, now so frequently and characteristically exhibited in our own planet, has yet scarcely appeared in the moon. The time will doubtless come, when, viewing it as a great cosmical agency, all such specialities belonging to this yet hidden power shall receive their solution."
The Ocean. – The next most important portion of the globe to man is that mighty reservoir of water which surrounds the land, penetrates into every large portion of it, supplies the moisture without which all life must rapidly perish, and forms the great means of intercourse, without which one-half of the globe would be ignorant of the existence of the other.
In the ocean, we have the complete contrast to the land, the whole giving an extraordinary evidence of that extreme diversity of means, which the Creator wills to exercise for every purpose of his creation. The land is all variety, the ocean is a plain of millions of square miles. The land never moves, the ocean is in perpetual movement. Below the surface of the land, all animal life dies; the ocean is inhabited through a great portion of its depth, and perhaps through its whole depth. The temperature of the land is as varying as its surface; the temperature of the ocean is confined within a few degrees. The temperature of the earth appears to increase with the depth to which man can descend; the temperature of the ocean, at a certain depth, seems always the same.
Even in that relation to beauty and grandeur, which evidently forms a part of the providential design, the sources of enjoyment to the human eye, in the land and the ocean, are strikingly different. On land, the sublime and the beautiful depend on variety of form – the mountain shooting to the skies, the valley deepening beneath the eye, the rush of the cataract, the sharp and lofty precipice, the broad majesty of the river, the rich and coloured culture of the distant landscape. In the ocean, the sublime arises from total uniformity. An unbroken surface, stretching round, as far as the eye can gaze, forms the grandeur; the clouds and colours of the sky, reflected on its surface, form the beauty. Even when the phenomena are most similar, the effect is different: the sunset of land and sea are equally magnificent; but the sunset on land is lovelier, from its inlaying of gold and purple light on the diversities of hill and valley, forest and field: at sea, it is merely one gorgeous blaze – splendour on cloud above and wave below. But moonlight at sea is lovelier than on land. Beautiful as it is, even on the imperfect outlines of trees and hills, a large portion of the lustre is broken and lost by the obstacles and varieties of the landscape. But at sea there is no obstruction; its lustre falls on a mighty mirror; all around is light, all above is majesty: the absence of all the sights and sounds of life deepens the sense of calm admiration, and the impression almost amounts to a feeling of the holy.
The ocean covers three-fourths of the globe, yet even this enormous extent has not been sufficient for the providential object of human intercourse. The Divine expedient was the formation of inland seas. Nothing in the distribution of land and sea is more remarkable, than the superior magnitude of the world of waters to the world of land, in a globe whose chief purpose was evidently the support of man. The Pacific alone is larger than all the land. From the west coast of America, to the eastern coast of Africa, spreads one sheet of water – a traverse of sixteen thousand miles. The valley of the Atlantic has a breadth of five thousand miles, while its length reaches from pole to pole – its surface is an area of more than twenty millions of square miles.
Yet, it is perfectly possible that this proportion was once of a different order. As we know nothing of the antediluvian world but by the Mosaic history, and as that history has not revealed the original boundaries of the land and sea, no positive conclusion can be obtained. Yet, from the deposits of marine products in the existing soil, it has been conclusively conjectured, that the land has been once the bed of the ocean, while the present bed of the ocean has been the land. The almost total absence of the human skeleton among fossils, and some old and dim traditions of a continent submerged, where the waters of the Atlantic now roll, may add to the conjecture. The globe then would have afforded room for a population threefold that which it is now destined to contain. If it is now capable of supporting sixteen times its present number, as has been calculated, it would then have been equal to the sustenance of little less than fifty thousand millions. Yet, what would be even that space to the magnitude of Jupiter; or that number to the beings of flesh and blood, however differing from man, which may at this moment, in that most magnificent planet, be enjoying the bounty of Providence, and replenishing a circumference of two hundred and forty thousand miles!
Uniform as the ocean is, it is a vast theatre of contrivances. To prevent the impurity which must arise from the decay of the millions of fish, and perhaps of quadruped and reptile life, constantly dying in its depths, – it is saline. To prevent the stagnation of its waters, which would reinforce the corruption, it is constantly impelled by currents, by the trade-wind, and by the universal tide. At the equator the tide moves with a rapidity which would shatter the continents; but it is met by shallows, by ridges of rock, and by islands; a vast system of natural breakwaters which modify its force, and reduce it to an impulse compatible with safety.
The water of the sea retains its fluidity down to four degrees below the freezing point of fresh water; the object is, perhaps, the preservation of the millions of animated beings contained in the waters; but as, in the tropic latitudes, its exposure to the sun might engender disease, or create tempests, vast refrigeratories are provided at both the poles, which are constantly sending down huge masses of ice to cool the ocean. Some of those floating masses are from ten to twelve miles long, and a hundred feet high above the water, with probably three hundred feet below. They have been met with two thousand miles on their way to the equator, and have sensibly cooled the sea for fifty miles round, until they wholly dissolved. Of course, on subjects of this order, human observation can do little more than note the principal effects – the rest can be only probable conjecture. It may be, that human sagacity has never ascertained the hundredth part of the purposes of any one of the great agents of nature. Still, it is the business of science to inquire, as it is the dictate of experience to acknowledge, that every addition to discovery gives only additional proof of the sleepless vigilance, boundless resources, and practical benevolence of the great Ruler of all.
The variety of uses derived from a single principle is a constant, and a most admirable, characteristic of nature. The primary purpose of the ocean is probably, to supply the land with the moisture necessary to production. But, the collateral effects of the mighty reservoir are felt in results of the first importance, yet of a wholly distinct order. The ocean refreshes the atmosphere, to a certain degree renews its motion, and obviously exerts a powerful agency in preventing alike excessive heat and excessive cold. The tides, which prevent its stagnation – a stagnation which would cover the earth with pestilence – also largely assist navigation in the estuaries, in the lower parts of the great rivers, and in all approaches to the shore. The currents, a portion of this great agency, (still perhaps to give us new sources of wonder,) fulfil at least the triple office of agitating the mass of ocean, of speeding navigation, and of equalising or softening the temperature of the shores along which they pass, in all directions. They seem equivalent to the system of high-roads and cross roads in a great country. It had been said of rivers, that "they are roads which travel;" but their difficulty is, that they travel only one way. The currents of the ocean obviate the difficulty, by travelling all ways. And, perhaps, we may look forward to a time when, by the command of wind and wave given by the steamboat, and by our increased knowledge of "ocean topography," if we may use the phrase; a ship may make its way across the ocean without ever being out of a current; a result which would be obviously a most important accession, if not to the speed, at least to the security of navigation.
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