------------------------------------
“They that go down to the sea in ships, that do business in great
waters; these see the works of the Lord, and his wonders in the
deep.”—PSALMS.
“With wonder mark the moving wilderness of waves,
From pole to pole through boundless space diffused,
Magnificently dreadful! where, at large,
Leviathan, with each inferior name
Of sea-born kinds, ten thousand thousand tribes,
Find endless range for pasture and for sport.
Adoring own
The Hand Almighty, who in channeled bed
Immeasurable sunk, and poured abroad,
Fenced with eternal mounds, the fluid sphere;
With every wind to waft large commerce on.
Join pole to pole, consociate severed worlds,
And link in bonds of intercourse and love
Earth’s universal family.”—MALLET.
That huge mass of waters impregnated with salt, which encompasses all
parts of the globe, and by the means of which, in the present improved
state of navigation, an easy intercourse subsists between the most
distant nations, is denominated the ocean, and has three grand divisions
assigned to it. First, that vast expanse of water which lies to the
westward of the northern and southern continents of America, and by
which those continents are divided from Asia. On account of the uniform
and temperate gales which sweep its surface within the tropics, it is
named the Pacific ocean; and has again been distinguished into the
northern and southern Pacific, (the equator being considered as the
dividing line,) and the Southern ocean, or South sea, being consequently
that part of the general assemblage of waters which is contained between
the fortieth degree of south latitude and the south pole. Its general
width is estimated at about ten thousand miles. Secondly, the Atlantic
ocean, which divides Europe and Africa from the two American continents,
and has a general width of about three thousand miles; while the waters
which occupy the polar regions are named the Northern sea. And, lastly,
the Indian ocean, which extends from the eastern shores of Africa along
the southern coasts of Asia, and has the same general width with the
preceding one.
Among the chief of those less expansive sheets of water, properly called
seas, may be mentioned the Baltic, the Mediterranean sea, and the Black
and Red seas. The Caspian sea, being entirely encompassed by land,
might, with more propriety, have been styled a lake; but as its water
possesses the quality of saltness, it is ranked among the seas. It is,
notwithstanding, certain that Lake Superior has a still greater
circumference, extending around its shores at least fourteen hundred
miles, while the extent of the Caspian does not exceed twelve hundred.
Of the origin of this division into different seas, and seas of
different depths, little is known; but it is highly probable that many
of the larger excavations and partitions now met with, have existed,
without much change as to their extent, from the creation. Others have
undoubtedly been the result of that conflict which is perpetually taking
place between the elements of land and water, and which has, for the
greater part, given rise to islands, isthmuses and peninsulas; while
subterraneous volcanoes, and the truly surprising and indefatigable
exertions of coral, madrepores, tubipores, and other restless and
multitudinous zoöphytes, have laid, and are daily laying, the foundation
of new islands and continents in the middle of the widest and deepest
seas.
The quantity of water in the ocean, not only remains constantly the
same, but, notwithstanding its most violent and incessant motion,
continues stable within certain limits. This, however, can not be
inferred from observation; for, although in the almost infinite variety
of disturbances to which the ocean is liable, from the action of
irregular causes, it may appear to return to its former state of
equilibrium, still it may be apprehended that some extraordinary cause
may communicate to it a shock, which, though inconsiderable at first,
may augment continually, and elevate it above the highest mountains. It
is, therefore, interesting to investigate the conditions which are
necessary for the absolute stability of the ocean. This has been
effected by the celebrated Laplace, who has demonstrated that the
equilibrium of the ocean _must_ be stable, if the density be _less_ than
the mean density of the earth, which is known to be the case. He has
likewise determined, by means of his refined analysis, that this
stability would cease to exist, if the mean density of the sea _were to
exceed_ that of the earth; so that the stability of the equilibrium of
the ocean, and the excess of the density of the terrestrial globe above
that of the waters which cover it, are reciprocally connected with each
other, and indicate infinite wisdom and contrivance in such an
adjustment.