sides of mountains are seen enveloped in mist. Condensation and attraction, in this way, concur to render mountains the nursing parents of streams. You cannot but have observed in the morning, when the dew is disappearing before the sun's rays, that it rolls in beautiful white folds up the acclivities towards the peaks. It is a lesson in physics, in which you are taught the origin of rivers.

As

What a spectacle is presented by the ocean, the grand reservoir, where all the rivers have their source! Sublime image of immensity and eternity, who can imagine the wonders of thine unfathomable depths, of thy incessant flux and reflux, of the resistless power of thy wrath in storms! Yet illimitable, perfidious, unfathomable, and thy bed whitened with the bones of thy victims, to thee we owe forests, fruits, verdure, flowers, every thing that gladdens spring or autumn. From the vast surface of every sea is continually steaming, in invisible vapor, the whole amount of the rains that fall, and the rivers that run over the whole earth. cending into the higher regions of the air, it is borne by the winds towards the mountains. In the magazines of hail and snow, it condenses, falls in rains, which fill the urns of innumerable mountain-sources, which unite to form rivers that roll back in majesty to the sea, where they are vaporized anew and raised once more into the air. In this eternal circle, I see the rivers rolling over my head in this transparent mist. I see trees, plants, and flowers, in the form of ærial vapor. In contemplating this perpetual circle of transformations of air into water, of that into vapors and clouds, and of rains into the substance of the innumerable tribes of vegetation, to be decomposed and to return to air and water again, who would not be inclined to believe with Thales, that water was the only element of the universe?

Compared with this magnificent apparatus, so powerful, and yet silent and invisible in its operations, to water the whole earth, how trivial appear those boasted hydraulic machines, which men have contrived for the irrigation of a few vineyards and fields? That is a proud work, by which one of our most beautiful cities is supplied with water by machinery

which the water itself puts in motion. A river is made to exert its own power to raise a part of its superfluous waters high in the air, whence, by its own laws, it conveys itself to the multitudes of the city. A power still more vást and artificial is raised from water itself in the form of steam, in which form it is subservient to raising water to elevations, whence whole cities may be supplied. But how insignificant are these proudest triumphs of art and human effort, compared with the sublime water-works of nature! The same rays of the sun, which, in their temperate culmination, cheer and brighten every thing, and in their fiercer ardors menace to destroy every thing, silently and invisibly pump up the vapors, which temper the burning brightness by a veil which the sun in this way draws over his own face.

I close this lecture, by presenting you the superb picture of the formation of clouds in the equatorial regions, as drawn by the powerful pencil of St Pierre. The trade winds from the northeast or southeast that constantly blow there, card the clouds through each other, like so many tufts of silk; then sweep them away to the west, crossing and recrossing them over each other, like the osiers interwoven in a transparent basket. They throw over the sides of this chequered work, the clouds which are not employed in the contexture; roll them into enormous masses as white as snow, draw them out along their extremities, and pile them upon each other like the cordilleras of Peru, moulding them into the shape of mountains, caverns, and rocks. They grow calmer towards evening, as if afraid of deranging their own workmanship. When the sun retires behind this magnificent web, you see a multitude of luminous rays transmitted through each interstice, of the most superb tinge of gold and orange. Divergent streams of light, radiating up the zenith from the sun, clothe the undetermined summits of this celestial barrier with fringes of gold, and strike with the reflections of their fires the pyramids of collateral ærial mountains, which then appear of silver and vermillion. At this moment of the evening are perceptible, amidst their reduplicated ridges, valleys stretching away into infinity. Those

celestial valleys present, in their different contours, inimitable soft shades melting into each other. You see, issuing from the cavernous sides, tides of light precipitating themselves in ingots of gold over rocks of coral. Here it is a gloomy rock pierced through and through, disclosing beyond the aperture, the pure azure of the firmament. There it is an extensive strand covered with sands of gold, stretching over the rich ground of heaven, poppy-colored, scarlet, and green as the emerald.

The reverberation of these colors diffuses itself over the sea, whose azure billows it glazes with saffron and purple. This sublime spectacle presents itself at the still and silent hour of evening prayer. The sailors lean over the gunwale and admire these ærial landscapes, which, by their grandeur, invite them to lift their hearts with their voices to heaven. The shifting colors, and the varying forms of these clouds, no pencil can pretend to imitate, and no language can describe.

LECTURE XXXVII.

IMMENSITY OF THE WATERS. TIDES.

How many countries are buried under the barren brine! How many cities might have been reared, how many men might have subsisted, where reigns a single, sterile, illimitable abyss? Why submerge two-thirds of the globe? Such are the questions, with which the impious have dared to attack Providence. The views which we have taken of nature, cannot but have convinced us, that where, in the arrangements of our world, we cannot at once trace the analogies and relations of things, and discern the intent of Providence in them, it is owing to our ignorance and feebleness of vision, rather than to the want of design. Our arrogant ignorance may propose the question, why it rains on

the ocean, and does not rain on the Sahara of the African desert? Were we able to trace all the relations of one arrangement in our system to the other, and the mutual influence of all upon each, we could probably be able satisfactorily to resolve questions more inexplicable than this. As far as we can trace these relations, all is the harmony of the most perfect adaptation. God dwells in a light that may well dazzle our perceptions. We are still abundantly warranted in believing, that not one of the phenomena of the physical universe is without its capacity of exposition, and without its utility. Between the lily of the valley, in the interior of a continent, and the ocean, distant hundreds of leagues, there is an admirable and invisible correspondence. The life of the one is identified with the laws of the other. From this immense abyss, so barren and useless in the eye of the unbeliever, proceed the elements of all life. Exhalations from this mass of brine, are wine in the delicious grape, flavor in the peach, apple, orange, anana; blue in the violet, gilding in the marigold, silver in the lily, purple in the piony, and verdure in the foliage. Thales affirmed, twenty centuries since, that water is the principle of all things. It is because this element is so indispensable, that it is diffused in such abundance. Therefore it flows from the hills and winds among the vallies, and is every where so accessible. But we have seen, that the circumambient air is the principle of water. May not light be the principle of air and the universal element of all things?

Instead of viewing the sea as a sterile waste in the kingdom of nature, let us sit upon its shore, and in the pauses of its resounding billows, let our hymns of gratitude to the author of nature be heard. As I strain my eye along its blue profound, as I inhale its humid air, as the waves whiten, and burst upon the shore, to be perpetually renewed, a throng of reflections upon the grandeur of God, and the immensity of this abyss, the image of his own greatness, rush upon my thoughts. What imagination can descend to its unsounded depths? I mark the billows, lashed by the winds, swelling, whitening, bursting, to be incessantly re

newed without a moment's repose. Measured by this image of eternity, how fleeting a thing is life, which like oceanbubble rises, bursts, and is lost in the bosom of the sea!

But while we contemplate this mass of waters in its ceaseless fluctuations, we note another phenomenon. The sea has retired from its shores. Where, a few moments since, the waves dashed, we now discover the strand laid bare. But the ocean is not emptied into space, nor will it, continuing to sink, show us the mysteries of its bed. In a few hours it will return, retire, and return again, in the same unchanging intervals to the end of time.

You might comprehend in advance, that these great movements would cause the descending waters of the rivers to recoil, and move back towards their sources. The migh

ty current of the Mississippi is thrown back more than a hundred miles by the comparatively small tides of the Gulf of Mexico. What a powerful reflux in the impetuous St Lawrence, the vast Amazon, the broad La Plata, at whose estuaries the tides run high !

The scanty knowledge of the ancients, in relation to the science of physics, prevented them from bringing forward any thing like a plausible solution of the causes of the tides. The philosopher of Stagira, Aristotle, following Alexander into India, was so astonished at seeing the ebbing and flowing of the tide, which does not take place in the Grecian seas, that he is said to have drowned himself in despair, at not being able to explain the phenomena to Alexander. Historians have taken pleasure, in painting the astonishment of that conqueror, when, in descending the banks of the Indus, he saw that great stream flowing back towards its source. Anxious to penetrate the causes of such a prodigy, he left his warriors, and stood in profound meditation upon the shore of the sea. Admiring the regularity of its movements, and affected with a sense of his own weakness, at the view of such a mighty and unchanging power, he admitted, that it was an empty illusion for him to impose himself upon the world, as a god.