edition.), but he had himself probably arrived at it independently.
Modern physical research tends to confirm it. The earth's centre of
gravity, as pointed out by Pratt from the existence of the Pacific
Ocean, does not coincide with its centre of figure, and it has been
conjectured that the Pacific Ocean dates its origin from the separation
of the moon from the earth.

The conjecture appears to be unnecessary. Love shows that "the force
that keeps the Pacific Ocean on one side of the earth is gravity,
directed more towards the centre of gravity than the centre of the
figure." ("Report of the 77th Meeting of the British Association"
(Leicester, 1907), London, 1908, page 431.) I can only summarise the
conclusions of a technical but masterly discussion. "The broad general
features of the distribution of continent and ocean can be regarded
as the consequences of simple causes of a dynamical character," and
finally, "As regards the contour of the great ocean basins, we seem
to be justified in saying that the earth is approximately an oblate
spheroid, but more nearly an ellipsoid with three unequal axes, having
its surface furrowed according to the formula for a certain spherical
harmonic of the third degree" (Ibid. page 436.), and he shows that this
furrowed surface must be produced "if the density is greater in one
hemispheroid than in the other, so that the position of the centre of
gravity is eccentric." (Ibid. page 431.) Such a modelling of the earth's
surface can only be referred to a primitive period of plasticity. If
the furrows account for the great ocean basins, the disposition of the
continents seems equally to follow. Sir George Darwin has pointed out
that they necessarily "arise from a supposed primitive viscosity or
plasticity of the earth's mass. For during this course of evolution the
earth's mass must have suffered a screwing motion, so that the polar
regions have travelled a little from west to east relatively to the
equator. This affords a possible explanation of the north and south
trend of our great continents." ("Encycl. Brit." (9th edition), Vol.
XXIII. "Tides", page 379.)

It would be trespassing on the province of the geologist to pursue the
subject at any length. But as Wallace ("Island Life" (2nd edition),
1895, page 103.), who has admirably vindicated Darwin's position, points
out, the "question of the permanence of our continents... lies at the
root of all our inquiries into the great changes of