[_Raised her primeval islands_. l. 36. The nucleus of the earth, still
covered with water, received perpetual increase by the immense
quantities of shells and coralloids either annually produced and
relinquishied, or left after the death of the animals. These would
gradually by their different degrees of cohesion be some of them more
and others less removable by the influence of solar tides, and gentle
tropical breezes, which then must have probably extended from one pole
to the other; for it is supposed the moon was not yet produced, and that
no storms or unequal winds had yet existence.

Hence then the primeval islands had their gradual origin, were raised
but a few feet above the level of the sea, and were not exposed to the
great or sudden variations of heat and cold, as is so well explained in
Mr. Whitehurst's Theory of the Earth, chap. xvi. Whence the paradise of
the sacred writers, and the golden age of the profane ones, seems to
have had a real existence. As there can be no rainbow, when the heavens
are covered with clouds, because the sun-beams are then precluded from
falling upon the rain-drops opposite to the eye of the spectator, the
rainbow is a mark of gentle or partial showers. Mr. Whitehurst has
endeavoured to show that the primitive islands were only moistened by
nocturnal dews and not by showers, as occurs at this day to the Delta of
Egypt; and is thence of opinion, that the rainbow had no existence till
after the production of mountains and continents. As the salt of the sea
has been gradually accumulating, being washed down into it from the
recrements of animal and vegetable bodies, the sea must originally have
been as fresh as river water; and as it is not yet saturated with salt,
must become annually more saline. See note on l. 119 of this Canto.]