The dual fluid envelopes: The aerial and liquid oceans defining the terraqueous world

“ The elevation of continents is still progressing slowly, and is being compensated for at some definite points by a perceptible sinking. All geognostic phenomena indicate a periodical alteration of activity in the interior of our planet. Probability of new elevations of ridges — p. 293-301 and notes.
g. The solid surface of the earth has two envelopes, one liquid, and the other aeriform. Contrasts and analogies which these envelopes — the sea and the atmosphere — present in their conditions of aggregation and electricity, and in their relations of currents and temperature. ”

“ THE atmosphere is commonly considered as a body of gases surrounding the globe, but hardly as a part of our sphere. We must, however, look upon it as being of the very substance of our earth, an integral part of the planet as truly as the waters or the solid crust. The geologist and the geographer, indeed, habitually speak of three envelopes of the globe, the atmosphere, the hydrosphere and the lithosphere. A certain assemblage of gases, all of which may be found in the waters and the rocks, remains in a more attenuated condition as the outer part of the earth. ”

“ The firm-set portion of the earth, composed of materials which became solid when the heat so far disappeared from the sphere that rocky matter could pass from its previous fluid condition to the solid or frozen state, is wrapped about by two great envelopes, the atmosphere and the waters. ”

“ Our planet has two envelopes, of which one, which is general — the atmosphere — is composed of an elastic fluid, and the other — the sea — is only locally distributed, surrounding, and therefore modifying, the form of the land. These two envelopes of air and sea constitute a natural whole, on which depend the difference of climate on the earth's surface, according to the relative extension of the aqueous and solid parts, the form and aspect of the land, and the direction and elevation of mountain chains. ”

“ As we have now passed in review the whole sphere of inorganic terrestrial life, and have briefly considered our planet with reference to its form, its internal heat, its electro-magnetic tension, its phenomena of polar light, the volcanic reaction of its interior on its variously composed solid crust, and, lastly, the phenomena of its two-fold envelopes — the aerial and liquid ocean — we might, in accordance with the older method of treating physical geography, consider that we had completed our descriptive history of the globe. ”

“ Again: the earth, as a whole, may be studied in its present forms, and the mutual action of all its parts—lands and seas, mountains and valleys, rivers, gulfs, and bays, currents of air and ocean—and the manner in which all these, by action and reaction, co-operate to produce climates and physical conditions such as we now find them. This is physical geography. Or, we may study the earth in its gradual progress toward its present condition—the changes which have taken place in all these parts, and consequent changes in climate; in a word, the gradual process of becoming what it now is. ”

“ There is the sun stage, in which the planet is hot enough to emit light. This is followed by the molten stage—hot, but lightless. Then comes the solidifying stage, with the formation of solid surfaces and ocean basins. The next stage is what we call the terraqueous stage, the age of sedimentary rocks. Our Earth is in this stage. Following this is the terrestrial stage, in which the oceans have disappeared, and, after that the dead stage, when air has departed. Mars is in the terrestrial stage, the stage following that of our planet, and preceding the dead, or final stage. ”

“ Before we proceed to study detailed problems, then, it is obviously necessary to look at some general points connected with the relief of the earth’s surface and its causes.
In the words of the physical geographer, [20] the earth’s surface consists of the solid crust, or lithosphere, of the mass of water forming the seas and oceans and constituting the hydrosphere, and of that envelope of gas which we call the atmosphere. Considered separately, each of these is the concern of special sciences, and not of the geographer proper. ”

“ The Atmospheric Ocean—Order in its Flow—Offices of the Atmosphere—Dangers lessened by Science—Currents of Atmosphere—Cause of Wind—Two Great Currents—Disturbing Influences—Calms—Variable Winds—Causes thereof—Local Causes of Disturbance—Gulf Stream—Influence—The Winds mapped out—A Supposed Case.
Fish are not the only creatures that live in this ocean. The human inhabitants of Earth, dwell at the bottom of an ocean of air, which encircles the globe. ”

“ The atmosphere that surrounds this earth is like a shell that is two hundred to three hundred or more miles in thickness. We live at the bottom of an immense ocean of gaseous matter, which envelops everything, and presses upon everything with a force which appears, at first, perfectly incredible, but whose actual amount admits of easy proof. Gravity being, so far as is known, common to all matter, it is natural to expect that gases, being material substances, should be acted upon by the earth’s attraction, as well as solids and liquids. ”

“ Properties of Air and Water, Snow and Ice, in Relation to Climate.—The great aerial ocean which surrounds us has the wonderful property of allowing the heat-rays from the sun to pass through it without its being warmed by them; but when the earth is heated the air gets warmed by contact with it, and also to a considerable extent by the heat radiated from the warm earth, because, although pure dry air allows such dark heat-rays to pass freely, yet the aqueous vapour and carbonic acid in the air intercept and absorb them. ”

“ The offices of the atmosphere are thus quaintly enumerated by Maury:—
“The atmosphere is an envelope or covering for the distribution of light and heat over the Earth; it is a sewer into which, with every breath we draw, we cast vast quantities of dead animal matter; it is a laboratory for purification, in which that matter is recompounded, and wrought again into wholesome and healthful shapes; it is a machine for pumping up all the rivers from the sea, and for conveying the water from the ocean to their sources in the mountains. ”

“ The facts are; first that water, being all but incompressible, is hardly any heavier, and just as liquid, at the greatest depth, than at the surface; and that therefore animals can move as freely in it in deep as in shallow water; and next, that as the fluids inside the body of a sea animal must be at the same pressure as that of the water outside it, the two pressures must balance each other; and the body, instead of being crushed in, may be unconscious that it is living under a weight of two or three miles of water. ”

“ By the influence of the simple law of gravitation, the planets are retained in their orbits, the moon directed in her course around the earth, and the whole of the bodies connected with the sun preserved in one harmonious system. By the same law the mountains of our globe rest on a solid basis, the rivers flow through the plains toward the seas, the ocean is confined to its prescribed boundaries, and the inhabitants of the earth are retained to its surface and prevented from flying upwards through the voids of space. ”

“ Such is the condition of the earth’s surface that the deepest places on this terrestrial globe are filled with water; thus oceans, lakes, pools, and rivers are formed.
That all living substances, whether vegetable or animal, are composed more than two-thirds of water.
That more than two-thirds of the entire quantity of food taken daily into the animal economy consists of water. That is to say, we feed on more than two-thirds of water.
Nothing living can maintain its existence without two-thirds of water. ”

“ The centre of the sphere of waters is the true centre of the globe of our world, which is composed of water and earth, having the shape of a sphere. But, if you want to find the centre of the element of the earth, this is placed at a point equidistant from the surface of the ocean, and not equidistant from the surface of the earth; for it is evident that this globe of earth has nowhere any perfect rotundity, excepting in places where the sea is, or marshes or other still waters. And every part of the earth that rises above the water is farther from the centre. ”

“ It is quite evident that the whole surface of the ocean--when there is no storm--is at an equal distance from the centre of the earth, and that the tops of the mountains are farther from this centre in proportion as they rise above the surface of that sea; therefore if the body of the earth were not like that of man, it would be impossible that the waters of the sea--being so much lower than the mountains--could by their nature rise up to the summits of these mountains. ”

“ Suppose now a body like the earth, but with its actual figure infinitely more irregular, having a sea circumfused around it, the water will descend into the lowest situations, and will so arrange itself, that its surface shall be perpendicular every where to the plumb-line, or to the direction of gravity, in which state only it can remain at rest. ”

“ You must understand, then, that all tide takes its rise in the free and open ocean under the action of the moon. No ordinary-sized sea like the North Sea, or even the Mediterranean, is big enough for more than a just appreciable tide to be generated in it. The Pacific, the Atlantic, and the Southern Oceans are the great tidal reservoirs, and in them the tides of the earth are generated as low flat humps of gigantic area, though only a few feet high, oscillating up and down in the period of approximately twelve hours. ”

“ The everlasting universe contains four elementary bodies. Two of these, namely, earth and water, are heavy, and are borne downwards by their weight; and as many are devoid of weight, and air, and fire still purer than air, nothing pressing them, seek the higher regions. ”

“ First; there is the variable Ocean of Air with its glorious banquet of light, its vapors, its twilight, and its shifting phantasmagoria of capricious creatures; coming into existence only to depart on the instant.
Second; there is the fixed Ocean of the earth, its undulating and vast waves as we see them from the tops of "earth o'er gazing mountains," the elevations which testify its antique mobility, and the sublimity of its mightier mountains clad in eternal snows. ”

“ It suggests to us this primitive energy of separation as the probable source of such light and heat in suns and stars as we now know them. It posits for us our own planet as an orb gathered in from the original cloud-mass, with outer surface cooled and corrugated, and with two great envelopes, atmospheric and oceanic, gaseous and liquid, still floating or precipitated around its denser core. It teaches us how the hard crust of the hot central mass has been uplifted here into elevated table-land or depressed there into hollow ocean-bed. ”

“ The aÂrial ocean rests partly on the solid earth, whose mountain chains and elevated plateaux rise, as we have already seen, like green wooded shoals, and partly on the sea, whose surface forms a moving base, on which rest the lower, denser, and more saturated strata of air. ”

“ The electric equilibrium is less frequently disturbed where the aerial ocean rests on a liquid base than where it impends over the land; and it is very striking to observe how, in extensive seas, small insular groups affect the condition of the atmosphere, and occasion the formation of storms. ”

“ It has already been shown that, although marshes and rivers, inland seas and lakes, yield by evaporation watery vapours to the air, the ocean is the great source of rain, whence it is lifted in vast quantities by the sun’s radiant heat, to be subsequently condensed by passing into cooler regions, or by contact with cold mountain peaks, falling to earth as a fertilizing shower or a devastating flood. ”

“ A few words will indicate the magnitude of the forces which are called into silent and comparatively unobserved operation in the atmosphere by the sun's heat in the production and recondensation of aqueous vapor. It has, as I noticed, been estimated that on the average five feet of water falls annually as rain over the whole earth. Supposing that condensation takes place at an average height of 3,000 feet above the surface, the force of evaporation must be equivalent to a power capable of lifting five feet of water, over the whole surface of the globe, 3,000 feet during the year. ”

“ The whole round of aquatic travel from ocean to air, and back to ocean again, proceeded at an everslackening pace. And here, if it so please geologists, may be found a reconciling of their demands for time to the relative pittance astronomy has been willing to dole them out, a paltry 50 or 100 millions of years, which like all framers of budgets they have declared utterly insufficient. For in early times the forces at work were greater, and by magnifying the means you quicken the process and contract the Earth's earlier eras to reasonable limits. ”

“ In fact, you produce currents of water, like currents of wind, by the converse of rarefaction.
“Recent discoveries,” says Humboldt, “have shown that the ocean has its currents exactly as the air. Living, as we do, upon the surface, they have been beyond our reach; but now, having obtained soundings to the depth of four miles, we have ascertained that there is a rush of icy water from the Pole to the Equator, just as there is a draft of air close to the earth into the centre of Africa. The Mediterranean offers an apparent anomaly of a higher temperature at great depths. ”

“ When any portion of the earth’s surface is periodically more heated above its normal temperature, or average for the year, than the neighboring region, the resulting abnormal temperature gradient causes a periodic surface wind tending toward the excessively heated place, and a counter wind above. That is, the cooler and heavier column of air sinking and uplifting the lighter, results in a lowering of the common center of gravity of the two 386columns of air, and thus furnishes the driving power of the wind. ”

“ In the plant the atoms are separated, in the animal they recombine. And as surely as the force which moves a clock’s hands is derived from the arm which winds the clock, so surely is all terrestrial power drawn from the sun. Leaving out of account the eruption of volcanoes and the ebb and flow of the tides, every mechanical action on the earth’s surface, every manifestation of power, organic and inorganic, vital or physical, is produced by the sun. His warmth keeps the sea liquid, and the atmosphere a gas, and all the storms which agitate both are blown by the mechanical force of the sun. ”

“ When the earth had become sufficiently cool to permit of the vapours now forming the ocean passing from the gaseous to the liquid form, the oceans descended from the heavens above to the earth beneath in the form of fresh water. In the lapse of subsequent ages the sea has become salt because ordinary river water, which always contains some small quantity of salt in solution, is continually bearing salt down to the sea. ”

“ If continents are disappearing in one direction, they are rising into fresh existence in another. Though the ocean tears down the cliffs against which it beats, the earth takes its revenge by upheaving the ocean's bed. When we look back, by the help of geological science, to the more remote past, through the epochs preceding our own, we find complete evidence that the globe has passed in succession through an infinitude of anterior states, by means of small modifications extending over a vast period of time, but not differing in essentials from those which we now see to be going on. ”

“ The shape of the seas and lands is fixed by the positions at which the upper level of the great water comes against the ridges which fret the earth's surface. These elevations are so disposed that about two thirds of the hard mass is at the present time covered with water, and only one third exposed to the atmosphere. ”

“ By an examination of the bottom of the sea, we discover that to be fully as irregular as the surface of the earth; we there find hills and vallies, plains and cavities, rocks and soils of every kind: we there perceive that islands are only the summits of vast mountains, whose foundations are at the bottom of the Ocean ”

“ The metallic stores of the earth, the vegetable and animal kingdoms were not transferred to any extent from place to place; the sea brought nothing from lands remotely foreign but drift-sand, cocoa-nuts, floating wood, ice masses, and seaweed, swept by the great currents from shore to shore. But now the seas are no barriers; they do not separate the continents but bind them together, and unite the destinies of nations in the closest manner. The great improvements in ocean navigation have entirely changed the relations of the entire globe. ”

“ The diffusion of the sea over three-quarters of the earth’s surface must also be taken into account. Thus the influence of the ocean in rendering men familiar with different parts of the world is far greater than that of the land. From the ocean comes a constant unifying influence which ever tends to reduce the disuniting effect of the separation of land from land. As yet no attempt to extend boundaries beyond the land out over the sea has been followed by lasting success. ”

“ They assert two principles of the physics of things below, namely, that the sun is the father, and the earth the mother; the air is an impure part of the heavens; all fire is derived from the sun. The sea is the sweat of earth, or the fluid of earth combusted, and fused within its bowels, but is the bond of union between air and earth, as the blood is of the spirit and flesh of animals. The world is a great animal, and we live within it as worms live within us. Therefore we do not belong to the system of stars, sun, and earth, but to God only ”