eighty-two years. Nothing more is required to
explain the unequal development of the arctic
and the antarctic icy regions.

Each of the earth's poles, therefore, is loaded
with a vast glacier, but of unequal dimensions
and elevation; as the antarctic mass is the more
considerable, the centre of gravity of the whole
mass of the globe is drawn into the southern
hemisphere, along the radius which terminates
at the South Pole, carrying with it the waters
spread over the earth, and laying bare a portion
of the continents of the northern hemisphere.
As the displacement of the centre of gravity
is slow, the displacement of the seas is also slow.
They gradually retreat from one hemisphere, and
gradually take possession of the other; and in
this secular movement there is nothing which
entitles it to the name of a catastrophe or a
grand convulsion of nature. Let us note the
consequences, and inquire what will happen ten
thousand five hundred years after the seas have
been amassed in the southern hemisphere.

Little by little, the northern glacier increases,
the southern diminishes. During a long period,
the deep waters, nearest to the centre of attraction,
transport themselves from the south to the
north. The northern seas insensibly rise, the
southern seas as gradually subside. On this
side of the equator, lowlands, shores, cultivated
fields, and forests are submerged; on the other
side of the equator, the land gains upon
the sea, which retires. But all this takes
place on a limited scale, and small changes
require long periods of time. At last, the
hour arrives when this regular and progressive
movement gives place to a sudden, a vast
perturbation of equilibrium; namely, when the
boreal glacier having reached its maximum of
extension, and the austral glacier its minimum,
this latter has become sufficiently softened and
rotten by the accumulated heat of the sun. It
is then broken up; and the instant of the break-up
sounds the knell of an universal cataclysm.
As soon as the fragments of the great southern
glacier are converted into floating icebergs,
drifting about at the mercy of the waves, the
attraction of the northern glacier becomes
preponderant; and the centre of gravity of the
globe, suddenly traversing the plane of the
equator, passes into the northern hemisphere,
dragging after it, in a mighty torrent, almost
the total mass of the waters.

Ten thousand five hundred years afterwards,
another deluge occurs, in an opposite direction;
and so on, during the whole enormous period
that the precession of the equinoxes has been
and shall be, a astronomical fact.

M. Adhémar's theory, resting on one of the
laws of the system of the world, has an
impregnable basis; but disputants may claim
leave to doubt the intensity of the results. Is
the cause assigned, capable of alternately
concentrating the great mass of the seas in the
opposite hemispheres? The question might be
resolved by observation; but unfortunately,
observations are wanting. We do not exactly
know, either the depth of the seas around the
South Pole, nor the height of the antarctic ice
above the level of the sea, nor its density. To
supply those deficiencies, our author is obliged
to reduce the question to a problem of statics.
The depth of the ocean increases regularly from
the North to the South Pole. The solid sphere
which forms the globe, and the liquid sphere
which is formed by the seas, are not parallel at
their surfaces, and the centre of one is about
half a league distant from the centre of the
other. The point is to demonstrate that the
eccentricity of these two spheres is caused by
the attraction of the ice accumulated at the
South Pole. With this view, the author inquires
into the conditions of equilibrium between the
earth, the sea, and the two polar glaciers. He
arrives at the result that the immense mass
of the seas is held in equilibrium by a force
three hundred and eighty-two leagues from its
natural centre. In order that the force of
attraction possessed by the antarctic glacier can
produce this astounding result, it must have a
height of twenty leagues. This seems a prodigious
altitude. But, by the help of the eclipses in which
the earth casts her shadow on the moon, something
may be ascertained respecting the projection of
the polar ice. Kepler relates that the eclipse of
the moon of the 26th of September, 1624, which
was total and almost central, surprised him
greatly; "for not only," he says, "the duration
of total darkness was short, but the remainder
of the duration of the eclipse, before and after
the total obscurity, was still shorter, as if the
earth were elliptical or lemon-shaped, and had a
shorter diameter across the equator than from
pole to pole."

It is curious to compare Adhémar's theory with
some well-known geological phenomena. A great
catastrophe has devastated the surface of the
globe, leaving in our hemisphere, to witness
its power, the extraordinary phenomenon which
has been named the diluvium of the north.
Innumerable blocks of all dimensions have
been torn from regions near the pole and have
been transported along every meridian, down to
the fifty-second parallel, and raised to altitudes
exceeding five hundred yards. They are
scattered over the plains and table-lands of the Old
and the New Worlds. In all cases, they have
been arrested by the heights, and they have
been stranded on the northern slopes of
mountains, whilst open grounds and lowlands have
admitted their passage. Their abundance and
their volume is in proportion to the latitude;
and the nearer they are to the pole, the more
considerable is their number and dimensions.
On beholding the sharpness of their edges, the
prominence of their angles, the freshness of their
fractures, and their perfect preservation, you
are tempted to say that some colossal hand,
clutching them at their point of departure, had
deposited them unaltered at their destination.

The whole of America which is situated
between Newfoundland and the Upper Mississippi,
is thickly strewn with these erratic boulders.
They all lie on the south or the south-east side
of the mountains from whence they come.