Blackwood's Edinburgh Magazine, Volume 66, No. 408, January 1849

These are peculiarities interesting to notice, and which may hereafter explain, or be explained by, other phenomena. Resemblances and analogies of this kind, whilst they are permitted only to direct and stimulate inquiry, have their legitimate place in science. It was a resemblance of this description, between the zig-zag course of the metalliferous veins, and the path of the lightning, which first suggested the theory, based, of course, on very different reasonings, that electricity had essentially contributed to the formation of those veins – a theory which Mrs Somerville has considered sufficiently sound to introduce into her work.

What lies within our globe is still matter of conjecture. The radius of the earth is 4000 miles, and by one means or another, mining, and the examination of the upheaved strata, and of what volcanoes have thrown out, we are supposed to have penetrated, with speculative vision, to about the depth of ten miles.

"The increase of temperature," writes Mrs Somerville, "with the depth below the surface of the earth, and the tremendous desolation hurled over wide regions by numerous fire-breathing mountains, show that man is removed but a few miles from immense lakes or seas of liquid fire. The very shell on which he stands is unstable under his feet, not only from those temporary convulsions that seem to shake the globe to its centre, but from a slow, almost imperceptible, elevation in some places, and an equally gentle subsidence in others, as if the internal molten matter were subject to secular tides, now heaving and now ebbing; or that the subjacent rocks were in one place expanded and in another contracted by changes in temperature."

Perhaps these "immense lakes or seas of liquid fire" are a little too hastily set down here in our geography. But of these obscure regions beneath the earth, the student must understand he can share only in the best conjectures of scientific men. Geology is compelled, at present, in many cases, to content herself with intelligent conjecture.

To return again to the surface of the earth, the first grand spectacle that strikes us is the mountains. Before it was understood how the mountain was the parent of the river, the noble elevation was apt to be regarded in the light of a ruin, as evidence of some disastrous catastrophe, and Burnett, in his Theory of the Earth, conceived the ideal or normal state of our planet to be that of a smooth ball, smooth as an egg. The notion not only betrays the low state of scientific knowledge in his age, but a miserable taste in world-architecture, which, we may remark in excuse for poor Burnett, was, almost as much as his scientific ignorance, to be shared with the age in which he lived. For it is surprising, with the exception of a few poets, how destitute men were, in his time, of all sympathy with, and admiration of, the grander and more sublime objects of nature. "We have changed all that!" The mountain range, pouring down its streams into the valleys on both sides, is not only recognised as necessary to the fertility of the plain; but, strange to say, we become more and more awake to its surprising beauty and magnificence. The description of the mountain ranges of the several continents of the world, forms one of the principal attractions of the study of physical geography, and one of the great charms of Mrs Somerville's book.

The mountains of Asia take precedence of all others in altitude and length of range.

"The mean height of the Himalaya is stupendous. Captain Gerard and his brother estimated that it could not be less than from 16,000 to 20,000 feet; but, from the average elevation of the passes over these mountains, Baron Humboldt thinks it must be under 15,700 feet. Colonel Sabine estimates it to be only 11,510 feet, though the peaks exceeding that elevation are not to be numbered, especially at the sources of the Sutlej. Indeed, from that river to the Kalee, the chain exhibits an endless succession of the loftiest mountains on earth: forty of them surpass the height of Chimborazo, one of the highest of the Andes, and several reach the height of 25,000 feet at least… The valleys are crevices so deep and narrow, and the mountains that hang over them in menacing cliffs are so lofty, that these abysses are shrouded in perpetual gloom, except where the rays of a vertical sun penetrate their depths. From the steepness of the descent the rivers shoot down with the swiftness of an arrow, filling the caverns with foam and the air with mist.

"Most of the passes over the Himalaya are but little lower than the top of Mont Blanc; many are higher, especially near the Sutlej, where they are from 18,000 to 19,000 feet high; and that north-east of Khoonawur is 20,000 feet above the level of the sea, the highest that has been attempted. All are terrific, and the fatigue and suffering from the rarity of the air in the last 500 feet is not to be described. Animals are as much distressed as human beings, and many of them die; thousands of birds perish from the violence of the winds; the drifting snow is often fatal to travellers, and violent thunder-storms add to the horror of the journey. The Niti Pass, by which Mr Moorcroft ascended to the sacred lake of Manasa, in Tibet, is tremendous: he and his guide had not only to walk bare-footed, from the risk of slipping, but they were obliged to creep along the most frightful chasms, holding by twigs and tufts of grass, and sometimes they crossed deep and awful crevices on a branch of a tree, or on loose stones thrown across. Yet these are the thoroughfares for commerce in the Himalaya, never repaired, nor susceptible of improvement, from frequent landslips and torrents.

"The loftiest peaks, being bare of snow, give great variety of colour and beauty to the scenery, which in these passes is at all times magnificent. During the day, the stupendous size of the mountains, their interminable extent, the variety and sharpness of their forms, and, above all, the tender clearness of their distant outline melting into the pale blue sky, contrasted with the deep azure above, is described as a scene of wild and wonderful beauty. At midnight, when myriads of stars sparkle in the black sky, and the pure blue of the mountains looks deeper still below the pale white gleam of the earth and snow-light, the effect is of unparalleled sublimity; and no language can describe the splendour of the sunbeams at daybreak streaming between the high peaks, and throwing their gigantic shadows on the mountains below. There, far above the habitation of man, no living thing exists, no sound is heard; the very echo of the traveller's footsteps startles him in the awful solitude and silence that reigns in these august dwellings of everlasting snow."

The table-lands of Asia are on a scale corresponding with its mountains. But the same elevation, it is remarked, is not accompanied with the same sterility in these parts of the world, as in the temperate zone. Corn has been found growing at heights exceeding the summit of Mont Blanc. "According to Mr Moorcroft, the sacred lake of Manasa, in Great Tibet, and the surrounding country, is 17,000 feet above the sea, which is 1240 feet higher than Mont Blanc. In this elevated region wheat and barley grow, and many of the fruits of Southern Europe ripen. The city of H'Lassa, in eastern Tibet, the residence of the Grand Lama, is surrounded by vineyards, and is called by the Chinese 'the Realm of Pleasure!'" Nevertheless the general aspect of the table lands is that of a terrific sterility. Here is a striking description of them. We should have been tempted to say, that in this singularly dark appearance of the sky at mid-day, there was something of exaggeration, if our own limited experience had not taught us to be very cautious in attributing exaggeration where the scenic effects of nature are concerned.

"In summer the sun is powerful at mid-day; the air is of the purest transparency, and the azure of the sky so deep that it seems black as in the darkest night. The rising moon does not enlighten the atmosphere; no warning radiance announces her approach, till her limb touches the horizon, and the stars shine with the distinctness and brilliancy of suns. In southern Tibet the verdure is confined to favoured spots; the bleak mountains and high plains are sternly gloomy – a scene of barrenness not to be conceived. Solitude reigns in these dreary wastes, where there is not a tree, nor even a shrub to be seen of more than a few inches high. The scanty, short-lived verdure vanishes in October; the country then looks as if fire had passed over it; and cutting dry winds blow with irresistible fury, howling in the bare mountains, whirling the snow through the air, and freezing to death the unfortunate traveller benighted in their defiles."

The description of the territory of the East India Company will be read with interest. We cannot afford space to extract it. Plains and valleys the very richest in the globe are to be found here, as also much rank marshy land, and also much jungle. "It has been estimated that a third of the East India Company's territory is jungle."

As a set-off against this jungle we have it intimated that, if proper search were made, gold would probably be found in this territory, as abundantly as in California. We sincerely hope no such discovery will be made. If there is a sure specific for demoralising a people, it is to involve them in the chase for gold, instead of that profitable industry which produces the veritable wealth for which gold has become the symbol and representative. The discovery of gold in one of our colonies would not only demoralise, it would impoverish. It would demoralise, by substituting for steady industry, with steady returns, a species of enterprise which has all the uncertainty and fluctuation of gambling; and it would finally impoverish by diverting labour from the creation of agricultural and manufacturing wealth, to the obtaining of the dry barren symbol of wealth, which, apart from its representative character, has but very little value whatever.

We will not look back towards Chimborazo and the Andes, as we should involve ourselves in long and tempting descriptions. In Africa, it is remarkable that we are little acquainted with the mountains. "No European has yet seen the Mountains of the Moon!" What a challenge to enterprising travellers! We know the level sands of Africa better than these elevations which have assumed so magnificent a title. What a terrific sterility does a large portion of this the most ill-fated of the great continents present! "On the interminable sands and rocks of these deserts no animal – no insect – breaks the dread silence; not a tree nor a shrub is to be seen in this land without a shadow. In the glare of noon the air quivers with the heat reflected from the red sand, and in the night it is chilled under a clear sky sparkling with its host of stars." The wind of heaven, which elsewhere breathes so refreshingly, is here a burning blast fatal to life; or else it drives the sand in clouds before it, obscuring the sun, and stifling and burying the hapless caravan.

In the new continent of America – if it still retains that title – the desert is comparatively rare. But its enormous forests have, in some regions, proved that excessive vegetation can assume almost as terrific an appearance as this interminable sterility.

"The forests of the Amazons not only cover the basin of that river, from the Cordillera of Chiquitos to the mountains of Parima, but also its limiting mountain-chains, the Sierra Dos Vertentes and Parima, so that the whole forms an area of woodland more than six times the size of France, lying between the 18th parallel of south latitude and the 7th of north, consequently inter-tropical and traversed by the equator. According to Baron Humboldt, the soil, enriched for ages by the spoils of the forest, consists of the richest mould. The heat is suffocating in the deep and dark recesses of these primeval woods, where not a breath of air penetrates, and where, after being drenched by the periodical rains, the damp is so excessive that a blue mist rises in the early morning among the huge stems of the trees, and envelops the entangled creepers stretching from bough to bough. A deathlike stillness prevails from sunrise to sunset, then the thousands of animals that inhabit these forests join in one loud discordant roar, not continuous, but in bursts. The beasts seem to be periodically and unanimously roused by some unknown impulse, till the forests ring in universal uproar. Profound silence prevails at midnight, which is broken at the dawn of morning by another general roar of the wild chorus. The whole forest often resounds when the animals, startled from their sleep, scream in terror at the noise made by bands of its inhabitants flying from some night-prowling foe. Their anxiety and terror before a thunder-storm is excessive, and all nature seems to partake in the dread. The tops of the lofty trees rustle ominously, though not a breath of air agitates them; a hollow whistling in the high regions of the atmosphere comes as a warning from the black floating vapour; midnight darkness envelops the ancient forests, which soon after groan and creak with the blast of the hurricane. The gloom is rendered still more hideous by the vivid lightning, and the stunning crash of thunder."

One of the most interesting subjects, of which mention is made in the work before us, is the gradual elevation and subsidence observed in some portions of these continents themselves. Just when the imagination had become somewhat familiar with the sudden but very partial upheaving of the earth by volcanic agencies, this new discovery came to light of the slow rising and sinking of vast areas of the land, and unaccompanied with any earthquakes or volcanic eruptions. In some parts the crust of the earth has sunk and risen again; in others, sort of see-saw movement on a most gigantic scale has been detected.

"There is a line crossing Sweden from east to west, in the parallel of 56° 3´ N. lat., along which the ground is perfectly stable, and has been so for centuries. To the north of it for 1000 miles, between Gottenburg and North Cape, the ground is rising; the maximum elevation, which takes place at North Cape, being at the rate of five feet in a century, from whence it gradually diminishes to three inches in a century at Stockholm. South of the line of stability, on the contrary, the land is sinking through part of Christianstad and Malmo; for the village of Stassten in Scania is now 380 feet nearer to the Baltic than it was in the time of Linnæus, by whom it was measured eighty-seven years ago."

It is evident that the elevation of the land, in relation to the level of the sea, may be produced either by an uprising of the continent or a depression of the bed of the ocean, permitting the waters to sink; as also the apparent depression of the land may be occasioned by an elevation in the bed of the ocean. This renders the problem somewhat more difficult to solve, because the causes we are seeking to discover may be sometimes operating at that part of the crust of the earth which is concealed from our view. Mr Lyell, who, in his Principles of Geology, has collected and investigated the facts bearing upon this subject, mentions the following as probable causes of the phenomena: —

1. "It is easy to conceive that the shattered rocks may assume an arched form during a convulsion, so that the country above may remain permanently upheaved. In other cases, gas may drive before it masses of liquid lava, which may thus be injected into newly opened fissures. The gas having then obtained more room, by the forcing up of the incumbent rocks, may remain at rest; while the lava, congealing in the rents, may afford a solid foundation for the newly raised district.

2. "Experiments have recently been made in America, by Colonel Patten, to ascertain the ratio according to which some of the stones commonly used in architecture expand with given increments of heat… Now, according to the law of expansion thus ascertained, a mass of sandstone, a mile in thickness, which should have its temperature raised 200° F., would lift a super-imposed layer of rock to the height of ten feet above its former level. But, suppose a part of the earth's crust one hundred miles in thickness, and equally expansible, to have its temperature raised 600° or 800°, this might produce an elevation of between two and three thousand feet. The cooling of the same mass might afterwards cause the overlying rocks to sink down again, and resume their original position. By such agency, we might explain the gradual rise of Scandinavia, or the subsidence of Greenland, if this last phenomenon should also be established as a fact on further inquiry.

3. "It is also possible that, as the clay in Wedgwood's pyrometer contracts, by giving of its water, and then by incipient vitrification; so large masses of argillaceous strata, in the earth's interior, may shrink, when subjected to heat and chemical changes, and allow the incumbent rocks to subside gradually. It may frequently happen that fissures of great extent may be formed in rocks, simply by the unequal expansion of a continuous mass heated in one part, while in another it remains in a comparatively low temperature. The sudden subsidence of land may also be occasioned by subterranean caverns giving way, when gases are condensed, or when they escape through newly formed crevices. The subtraction, moreover, of matter from certain parts of the interior, by the flowing of lava and of mineral springs, must, in the course of ages, cause vacuities below, so that the undermined surface may at length fall in."16

Two agencies of the most opposite, character have apparently been, at all times, acting on the crust of the earth to change its form, or add to the surface of dry land – the volcano and the insect! – the one the most sudden and violent imaginable, producing in a short time the most astonishing effects; the other gradual, silent, and imperceptible, yet leaving the most stupendous monuments of its activity. The volcano has thrown up a mountain in a single night; there is an instance, too, on record, where a mountain has quite as suddenly disappeared, destroying itself in its own violent combustion, and breaking up with repeated and terrific explosions. On the other hand, besides what has been long known of the works of the coral insect, the microscope has revealed to us that huge cliffs have been constructed of the minute fossil shells of animalcule. These creatures, abstracting from the water, or the air, or both, the minute particles of vegetable or other matter they hold in solution, first frame of them their own siliceous shells, and then deposit these shells by myriads, so as ultimately to construct enormous solid mounds out of imperceptible and fluent particles.

Astonishing, indeed, is the new world of animals invisible to the naked eye, which science has lately detected.

"Professor Ehrenberg," says Mrs Somerville, "has discovered a new world of creatures in the infusoria, so minute that they are invisible to the naked eye. He found them in fog, rain, and snow, in the ocean and stagnant water, in animal and vegetable juices, in volcanic ashes and pumice, in opal, in the dusty air that sometimes falls on the ocean; and he detected eighteen species twenty feet below the surface of the ground in peat earth, which was full of microscopic live animals: they exist in ice, and are not killed by boiling water. This lowest order of animal life is much more abundant than any other, and new species are found every day. Magnified, some of them seem to consist of a transparent vesicle, and some have a tail; they move with great alacrity, and show intelligence by avoiding obstacles in their course: others have siliceous shells. Language, and even imagination, fails in the attempt to describe the inconceivable myriads of these invisible inhabitants of the ocean, the air, and the earth."

With every great change, however brought about, in the surface of the earth, and the climate of its several regions, it appears that, either by the direct agency of the Omnipotent Creator, or through the intermediate operations of laws which are at present profound secrets to us, a corresponding change takes place in the forms of animal life, and in the whole vegetable kingdom. Modern science presents no subject to us of more interest than this, and none apparently so inscrutable. Nor does the examination of the globe, as it exists before us at this moment, with its various floras and faunas, at all assist us in forming any conception of the law by which the geological series (if we may so term it) of animal life, has been regulated, for the distribution of the several animals over the several countries and climates of the world follows no rule that one can detect. Of course, no animal can exist where provision has not been made for its subsistence, but the provision has been made with the same abundance in two countries, and in the one the animal is found, and the other not. We should ask in vain why the horse was found a native of the deserts of Tartary, and why it was originally unknown to the plains of America? Nor can any cause be detected for the difference between the congeners, a representative species of one continent or island, and those of another. And not only have the larger animals an arbitrary territory marked out to them by nature, but birds, and even insects, are separated and grouped together in the same unaccountable manner. The chapters which Mrs Somerville has devoted to this subject will be read, especially by those to whom the topic is new, with extreme interest. They are enlightened and judicious.

It is a natural supposition to make, that, in the series of animals which at great geological periods have been introduced upon the earth, there has been a progression, so that each new form of animal life has been, in some marked manner, superior to that which is substituted. The comparative anatomist has not sanctioned this opinion; he tells us that he finds the same "high organisation" in the fossil saurians of a bygone world, as in the lions and leopards of the present day. But we would observe that the presence of this "high organisation" is not sufficient to determine the question. We should be surprised, indeed, if any creature were to be found whose structure was not perfectly adapted to the mode of life it was destined to lead. But it is permissible to compare one animal with another in its whole nature, and the character of its existence. The pig has the same high organisation as the dog, yet we should certainly prefer the one animal to the other; we should say that it was calculated for a happier life. We cannot suppose that a bird is not a more joyous creature than the worm or the snail. The adaptation of the whole form and structure to a pleasurable existence, and not what is termed high organisation, is that which we must regard, in estimating the superiority of one animal to another. Now, in this respect, there surely has been a progression from the earliest epochs. The crocodile and the tortoise are, amongst the animals which now exist, those which most resemble some of the more remarkable of the extinct genera. They are as perfectly adapted, no doubt, as any other creature, to their peculiar mode of being; but that mode of being is not an enviable one. The long stiff unwieldy body of the one, and the slow movement, with the oppressive carcase, of the other, are not consistent with vivid animal enjoyment. The crocodile, accordingly, lies motionless for hours together —waits for its prey – and slumbers gorged with food. And for the tortoise, it appears to lead a life as near to perpetual torpor as may be. Pass through a museum, and note those huger animals, the elephant and the rhinoceros, the seal or walrus, all those which most remind us of the gigantic creatures of the antediluvian world, and compare them with the horse, the deer, the dog, the antelope. Surely the latter present to us a type of animal life superior to the former – superior, inasmuch as the latter are altogether calculated for a more vivacious, sprightly, and happy existence. We must not venture to remark on their greater comparative beauty, for we shall be told that this is a matter for our own peculiar taste. We should not be contented to be so easily silenced on this head, but we should require far more space than we have now at our disposal to defend our æsthetic notions.

We have found ourselves imperceptibly conducted from the inanimate to the animate creation; we shall proceed, therefore, with the same topic, in the few farther extracts we shall be able to make from the work before us. Indeed, with so vast a subject, and so brief a space, it would be idle to affect any great precision in the arrangement of our topics; enough if they follow without abruptness, and are linked together by natural associations of thought.