The following lines, descriptive of the largest mass of fresh water m the world, may serve to direct the attention of the reader to this sublime and beautiful object, in the scenery of our own continent: :

LAKE SUPERIOR.

Father of lakes! thy waters bend

Beyond the eagle's utmost view,
When, throned in heaven, he sees thee send
Back to the sky its world of blue.

Boundless and deep, the forests weave
Their twilight shade thy borders o'er,
And threatening cliffs, like giants, heave
Their rugged forms along thy shore.

Pale Silence, 'mid thy hollow caves,

With listening ear in sadness broods,

Or startled Echo o'er thy waves

Sends the hoarse wolf-notes of thy woods.

Nor can the light canoes, that glide
Across thy breast like things of air,
Chase from thy lone and level tide
The spell of stillness, deepening there.

Yet round this waste of wood and wave,
Unheard, unseen, a spirit lives,
That, breathing o'er each rock and cave,
To all a wild, strange aspect gives.

The thunder-riven oak, that flings
Its grisly arms athwart the sky,
A sudden, startling image brings
To the lone traveller's kindled eye

The gnarled and braided boughs, that show
Their dim forms in the forest shade,

Like wrestling serpents seem, and throw
Fantastic horrors through the glade.

The very echoes round this shore

Have caught a strange and gibbering tone,
For they have told the war-whoop o'er,
Till the wild chorus is their own.

Wave of the wilderness, adieu !

Adieu, ye rocks, ye wilds and woods!
Roll on, thou element of blue,

And fill these awful solitudes!

Thou hast no tale to tell of man, -

God is thy theme. Ye sounding caves, ·
Whisper of Him, whose mighty plan
Deems as a bubble all your waves!

THE OCEAN.-This may be described as a sheet of water, resting in the hollows of the solid structure of our planet, and covering not less, probably, than two thirds of the entire surface. From calculations, its greatest depth is believed to be about 30,000 feet, or between four and five miles, which, it may be remarked, is near the greatest height of any land above the surface of the ocean. But the greatest depth which has been ascertained by actual measurement is not more than 5000 feet; for such is the pressure and density of the liquid mass at that depth, that no sounding-lead, or apparatus possessed by mariners, can possibly be made to sink below that point from the surface.

The quantity of water composing the ocean, by the unalterable laws of evaporation and condensation, remains always at a fixed poin, there being neither increase nor decrease. It has beer remarked by Laplace, that

if the existing waters of the ocean were increased only one fourth, the earth would be drowned, with the exception of some of the highest mountains; and that if, on the other hand, the waters were diminished in the same proportion, the largest rivers would dwindle to the capacity of brooks, and some of the principal arms of the sea would entirely disappear, while at the same time the earth would be deprived of its due proportion of humidity, and the face of nature be dried up and rendered desolate. Broad, therefore, as are the limits of the ocean, they are only in exact agreement with the wants and arrangements of nature in the habitable portion of the globe, and as such afford a convincing testimony of the power, wisdom, and goodness of the Divine

Creator.

The bottom or bed of the ocean is marked by the same irregularities of surface as the dry ground. It consists of heights and hollows, rocky protuberances and caverns, hills and vales, sandbanks and reefs, of every imaginable form and extent. Like the land, also, it bears a luxuriant vegetation, consisting of plants of various kinds, all of which are exactly suited to their respective situations. The sea has likewise its tribes of animals, from the huge whale down to the minute coral insect, by whose incessant labors the hardest rocky substances are constructed and reared to the surface of the waters. When the more elevated protuberances in the bed of the ocean are raised above the surface level, they assume, as is well known, the character of islands, and when of a large size, of continents. Thus, the tracts of dry land are in one sense the tops of mountains rising from the bosom of the deep. How islands

are formed, sometimes by the action of volcanoes bursting upwards in showers of lava in the midst of the sea, and sometimes by the gradual accumulation of matter deposited by coralline insects; and also how tracts of land are added to continents, and also sometimes taken from them, by the influence of currents, rivers, and other natural causes, are explained by geology.

TIDES.—The waters of the sea may exhibit to the eye a calm, unruffled surface, when not agitated by winds, but they are never altogether still. Their ceaseless motion, which has the important effect of preserving them from stagnation, is caused by two great risings and depressions, or flowings and ebbings, of the waters, in the course of twenty-four hours, known by the name of tides. The two tides or flowings of the sea are experienced daily all over the globe, though in some seas, from peculiar local causes, they are less powerful than in other places. It is not a little remarkable, that the condition of high water or full tide occurs at directly opposite sides of the earth at the same time. When it is high water at longitude 0, it is also high water at longitude 180, and so on with every other two opposite points of the earth, on the same parallel of latitude.

It has been ascertained, beyond all reasonable doubt, that the tides are caused by the attractive influence of the moon. By the universal law of attraction or gravitation, all masses of matter have a tendency to be at tracted or drawn towards each other. The moon, therefore, as a mass of matter, in passing round the earth, has a tendency to draw the earth after it, or out of its natural relative position, and it really does so to a small extent. As it passes round, it draws up the

waters in a protuberance, or, in common language, draws a huge wave after it. But it also draws the land beneath the protuberance, and so causes the opposite side of the globe to be drawn away from the ocean, leaving the waters there to form a similar protuberance, or high wave. In the one case, the water is drawn directly up or towards the moon; in the other, the water is in some shape left behind by the land being pulled away from it. In both, a similar effect is produced; two high tides are caused at opposite extremities of the earth. Where the higher part of either of these great billows strikes our coast, we have the phenomenon of high water; and when the lower touches us, it is low water. Each of the waves is brought over any . given place in the circumference of the earth in twentyfour hours, so as to cause high water twice a day. The sun is also known to have a certain attractive influence on the waters of the ocean, but, from the great distance of that luminary, the effect is comparatively small. But when this minor influence of the sun coincides with that of the moon, or acts in the same way, we perceive a marked increase in the tides; on such occasions we have what are called spring or large tides. When the solar and lunar attractions act in opposition, we have neap or small tides. The spring tides happen twice a month, when the moon is at full and change; and the neap when the moon is in the middle of its orbit, between those two points.

A tide requires six hours to rise, which it does by small impulses or ripplings of the water on the shore, and six hours to ebb or fall; but every successive high water is from twenty to twenty-seven minutes later than