Читать книгу Blackwood's Edinburgh Magazine, Volume 65, No. 402, April, 1849 - Various - Страница 2

In this age of scientific illustration, no more splendid work has been produced than the one of which we now give some general notice to our readers. It is not our purpose to panegyrise either the work or the author; but it is only justice to say, that no work more distinguished by completeness of knowledge on its subject – by the novelty, variety, and depth of its researches – by the skill of its arrangement, and by the beauty of its engravings and typography – has ever appeared in this country, or in any other. It is a magnificent tribute to the science and to the skill of England.

The author, in his desire to acknowledge his obligations, by stating that his work is founded on the Physical Atlas of Professor Berghaus, has done himself injustice. His volume, though naturally availing itself of all contemporary knowledge, exhibits all the originality which can make it his own.

Of all modern sciences, the science of the globe has made the most rapid, the most remarkable, and the most important progress. Bacon makes the fine remark, that while the works of man advance by successive additions, the works of Nature all go on at once: thus the machinist adds wheel to wheel, and spring to spring, but the earth produces the tree, branch and bark, trunk and leaf, together. There is something analogous to this combined operation in physical geography: a whole crowd of remarkable discoveries seem to have burst on us at once, expressly designed to invigorate and impel our progress in geographical science. Thus, our century has witnessed new phenomena of magnetism, new laws of heat and refrigeration, new laws even of the tempest, new rules of the tides, new expedients for the preservation of health at sea, new arrangements for the supply of fresh food, and even for the supply of fresh water by distillation, and all tending to the same object – the knowledge of the globe.

The use of steam, to which modern mechanism has given almost a new existence, and certainly a new power – the conquest of wind and wave by the steam-ship, and the almost miraculous saving of time and space by the steam-carriage; the new necessity of remote enterprise, originating in the urgency of commercial and manufacturing difficulties; the opening of the thousand islands of the Indian Archipelago, till now known to us as scarcely more than the seat of savage life, or the scene of Oriental fable; the breaking down of that old and colossal barrier of restrictions and prejudices, which, more than the wall of China, excluded England from intercourse with a population amounting to a third of mankind; and most of all, those vast visitations of apparent evil, which the great Disposer of things is evidently transmuting, year by year, into real good, by propelling the impoverished multitudes of Europe into the wildernesses of the world – all exhibiting a stupendous combination of simple means, and a not less astonishing convergency to the one high purpose, the mastery of the globe – place Physical Geography at the head of the sciences essential to the happiness and power of humankind.

In the glance which we shall give at this great science, we look only to the external structure of the earth; briefly protesting against all those theories which refer its origin to an earlier period, or a longer process, than the "six days" of Scripture. It is true, that Moses may not have been a philosopher, though the man "learned in all the wisdom of the Egyptians" may have known more than many a philosopher of later days. It is equally true, that the object of the Book of Genesis was not to give a treatise on geology. But Moses was a historian – it is the express office of a historian to state facts; and if Moses stated the "heavens and the earth, and all that therein is," to have been created and furnished in "six days," we must either receive the statement as true, or give up the historian as a fabricator. But if we believe, in compliance with the Divine word, that "all Scripture is by inspiration of God," by what subterfuge can we escape the conclusion, that the narrative of Genesis is divine? Or if, in the childish scepticism of the German school, we require a more positive testimony, what can be more positive than the declaration of the commandment of the Sabbath, "that in six days God made heaven and earth;" founding also upon this declaration the Sabbath – an institution meant for every age, and for the veneration and sanctification of every race of mankind? If such a declaration can be false, what can be true? If ever words were plain, those are the words of plainness. The law of Sinai was delivered with all the solemnities of a law forming the foundation of every future law of earth. It would have been as majestic, and as miraculous, to have fixed the creation at a million of years before the being of Adam. But we can discover no possible reason for the history, but that it was the truth. That truth is divine.

If the geologist shall persist in repeating, that the phenomena are incompatible with the history, our reply is, "Your science is still in its infancy – a science of a day, feebly beginning to collect facts, and still so weak as to enjoy the indulgence of extravagant conclusions. There have been a thousand theories of creation – each popular, arrogant, and self-satisfied, in its own time; each swept away by another equally popular, arrogant, and self-satisfied, and all equally deserving of rejection by posterity. You must acquire all the facts, before you can be qualified to theorise. The last and most consummate work of genius, and of centuries, is a true theory."

But, without dwelling further on this high subject, we must observe, that there is one inevitable fact, for which the modern geologist makes no provision whatever; and that fact is, that the beginning of things on the globe must have been totally different from the processes going on before our eyes. For instance, Adam must have been created in the full possession of manhood; for, if he had been formed an infant, he must have perished through mere helplessness. When God looked on this world, and pronounced all to be "very good" – which implies the completion of his purpose, and the perfection of his work – is it possible to conceive, that he looked only on the germs of production, on plains covered with eggs, or seas filled with spawn, or forests still buried in the capsules of seeds; on a creation utterly shapeless, lifeless, and silent, instead of the myriads of delighted existence, all enjoying the first sense of being?

But, if the first formation of the world of life must have been the act of a vast principle, to which we have no resemblance in the subsequent increase and continuance of being, what ground have we for arguing, that the common processes of material existence in our day must have been the same in the origin of things? On the whole, we regard the declaration – "In six days God made the heavens, and the earth, the sea, and all that in them is," as an insuperable bar to all the modern fantasies of the geologist, as a direct rebuke to his profaneness, and as a solemn judgment against his presumption.

The whole surface of the globe gives striking evidence of design, and of design contemplating the service of man. But one of the most remarkable evidences of that design is given in the Mountain Map of the globe. Variety of temperature, the supply of water, and the change of level, are essential to variety of production, to fertility of soil, and to the vigour and health of the human frame – the expedient to meet them all is provided in the mountain districts of the great continents. A mountain chain girdles the whole of the mass of land from the Atlantic to the Sea of Kamchatka. Minor chains, some parallel, some branching from the great northern chain, and some branches of those branches, intersect every region of the globe. The whole bears a remarkable resemblance to the position of the spine in the human frame, with its collateral muscular and venous connexion with the body. An outline view of the mountains of our hemisphere would be strikingly like a sketch of the human anatomy. The general formation of the countries north and south of those chains is early the same – vast plains, extending to the sea, or traversed and closed in by a bordering chain. The great Tartarian desert is a plain extending, under various names, five thousand miles from west to east.

Spain is a country of mountains, or rather a vast table-land, intersected by six ranges of lofty, rugged, and barren hills. Northern Africa is a basin of plains, surrounded by vast ridges. Morocco, Algiers, and Tunis, find in those hills at once their frontiers and their fertility. The Pyrenees form a chain of nearly three hundred miles long, and upwards of fifty broad – a province of mountains, intersected by valleys of romantic beauty and exuberant fertility. But the Alps, from their position between the two most brilliant nations of the Continent – France and Italy – and from the extraordinary series of memorable events of which they have been the theatre, since the earliest periods of European history, are the most celebrated range of mountains in the world. The higher Alps, beginning at the Gulf of Genoa, and extending north and east through the Grisons and the Tyrol, stretch between four and five hundred miles. They then divide into two branches, one of which reaches even to the Euxine. The breadth of the great range is, on an average, a hundred and fifty miles.

The Apennines, another memorable chain, also beginning at the Gulf of Genoa, strike direct through the heart of Italy, and end in Calabria – a line of eight hundred miles. Dalmatia and Albania are knots of hills; Pindus, and the mountains of Northern Greece, are bold offsets from the Eastern Alps.

Among those wonderful arrangements, the table-lands are perhaps the most wonderful. In the midst of countries where everything seemed to tend to the mountainous form, we find vast plains raised almost to a mountainous height, yet retaining their level. This form peculiarly occurs in latitudes of high temperature. The centre of Spain is a table-land of more than ninety-two thousand square miles – one half of the area of Spain.

The country between the two ranges of the Atlas is a table-land, exhibiting the richest products, and possessing the finest climate, of Northern Africa. Equatorial Africa is one immense table-land, of which, however, we can only conjecture the advantages. Whether from the difficulty of approach, the distance, or the diversion of the current of adventure to other quarters of the world, this chief portion of the African continent continues almost unknown to Europeans. The central region is a blank in our maps, but occasional tales reach us of the plenty, the pomp, and even of the civilisation and industry of the table-land. The centre of India is a table-land, possessing, in that region of fire and fever, a bracing air, and a productive, though rugged soil.

The table-lands of Asia partake of the characteristic magnitude which belongs to that mighty quarter of the globe. That of Persia has an area of more than a million and a half of square miles. That of Tibet has an area of six times the extent, with a still greater elevation above the level of the sea – its general altitude being about the height of Mont Blanc, and, in some instances, two thousand feet higher. The mean altitude of the Persian plateau is not above four thousand feet.

We have adverted to those formations of vast elevated plains in the midst of countries necessarily exposed to extreme heat, as one of the remarkable instances of providential contrivance, if we must use that familiar word in such mighty instances of design, for the comfort of animated being. We thus find, in the latitudes exposed to the fiercest heat of the sun, a provision for a temperature consistent with the health, activity, and industry of man. Persia, which, if on the level of the sea, would be a furnace, is thus reduced to comparative coolness; Tibet, which would be a boundless plain of fiery sand, exhibits that sternness of climate which makes the northern Asiatic bold, healthy, and hardy.

If the Tartar ranger over those lofty plains is not a model of European virtue, he at least has not sunk to the Asiatic slave; he is bold, active, and has been, and may be again, an universal conqueror. The same qualities have always distinguished the man of the table-land, wherever he has found a leader. The soldiery of Mysore no sooner appeared in the field, than they swept all Hindostan before them; the Persians, scarcely two centuries since, ravaged the sovereignty of the Mogul; and the tribes of the Atlas, even in our own day, made a more daring defence of their country, than all the disciplined forces of the Continent against Napoleon.

The two most remarkable ranges of Asia are, the Caucasus, extending seven hundred miles from west to east, with branches shooting north and south; and the Himalaya, a mountain chain of nearly three thousand miles in length, uniting with the Hindoo Coosh and the mountains of Assam. This range is probably the loftiest on the globe, averaging eighteen thousand feet – several of the summits rising above twenty-five thousand. Many of the passes are above the summit of Mont Blanc, and the whole constitutes a scene of indescribable grandeur, a throne of the solitary majesty of Nature.

But, another essential use of the mountain chains is their supply of water – the fluid most necessary to the existence of the animal and vegetable world, – and this is done by an expedient the most simple, but the most admirable. If the surcharge of the clouds, dashing against the mountain pinnacles, were to be poured down at once, it must descend with the rapidity of a torrent, and deluge the plains. But, those surcharges first take a form by which their deposit is gradual and safe, and then assume a second form, by which their transmission to the plains is gradual and unintermitting. They descend on the summits in snow, and are retained on the sides in ice. The snow feeds the glacier; the glacier feeds the river. It is calculated that, without reckoning the glaciers of the Grisons, there are fifteen hundred square miles of glacier in the Alps alone, from a hundred to six hundred feet deep. The glacier is constantly melting, from the mere temperature of the earth; but, as if this process were too slow for its use, it is constantly moving downwards, at a certain number of feet a-year, and thus bringing the great body of ice more within the limit of liquefaction. All the chief rivers of Europe and Asia have their rise in the deposits of the mountain glaciers.

In addition to all these important uses, the mountains assist in forming the character of man. The mountaineer is generally free from the vices of the plain. He is hardy and adventurous, yet attached to home; bold, and yet simple; independent, and yet unambitious of the wealth or the distinctions of mankind. Whether shepherd or hunter, he generally dies as he lived; and, though daring in defence of his hills, he has seldom strayed beyond them for the disturbance of mankind. The Swiss may form an exception; but their hireling warfare is not ambition, but trade. Their nation is pacific, while the individuals let themselves out to kill, or be killed. The trade is infamous and irreligious, offensive to human feeling, and contrary to human duty; but it has no more reference to the habits of the mountaineer than the emigration to California has to the habits of the clown of Massachusets; the stimulant only is the same – the love of gold.

We have adverted to the mountain system of the globe, from its giving a remarkable illustration of the Divine expediency. We judge of power by the magnitude of its effects, and of wisdom by the simplicity of its means. In this instance the whole of the results seem to arise from the single and simple act of raising portions of the earth's surface above the general level. Yet from this one act, what a multitude of the most important conditions follow! – variety of climate, variety of production, the temperature of Europe introduced into the tropics, health to man and the inferior animals, the irrigation of the globe, the defence of nations, and the actual enlargement of the habitable spaces of the globe, by the elevated surface of the hills – not to mention the beauty and sublimity of the landscape, which depend wholly on the colours, the forms, and the diversity 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.

Those ocean traversers evidently belong to a system. Some are permanent, some are periodical, and some are casual. The permanent arise chiefly from the effect of the flow from the poles to the equator. Descending from the poles in the first instance, they pour north and south. They gradually feel the earth's rotation; but on their arrival at the tropics, being still inferior in velocity to the equatorial sea, they seem to roll backwards; in other words, they form a current from east to west. This current is farther impelled by the trade-winds.

The progress of this great perpetual current includes almost every part of the ocean. In going westward, it necessarily rushes against the coast of America, where it divides into two vast branches, one running south with great force, and the other north-west. A succession of currents, all connected, obviously form a "moving power" to prevent the stagnation of the ocean, and, by their branches, visit every shore of the globe.