Meteorology   

and perish and the same parts of the earth were not always moist,

the sea must needs change correspondingly. And if the sea is always

advancing in one place and receding in another it is clear that the

same parts of the whole earth are not always either sea or land, but

that all this changes in course of time.

So we have explained that the same parts of the earth are not always

land or sea and why that is so: and also why some rivers are perennial

and others not.

Book II

1



LET us explain the nature of the sea and the reason why such a large

mass of water is salt and the way in which it originally came to be.

The old writers who invented theogonies say that the sea has

springs, for they want earth and sea to have foundations and roots

of their own. Presumably they thought that this view was grander and

more impressive as implying that our earth was an important part of

the universe. For they believed that the whole world had been built up

round our earth and for its sake, and that the earth was the most

important and primary part of it. Others, wiser in human knowledge,

give an account of its origin. At first, they say, the earth was

surrounded by moisture. Then the sun began to dry it up, part of it

evaporated and is the cause of winds and the turnings back of the

sun and the moon, while the remainder forms the sea. So the sea is

being dried up and is growing less, and will end by being some day

entirely dried up. Others say that the sea is a kind of sweat exuded

by the earth when the sun heats it, and that this explains its

saltness: for all sweat is salt. Others say that the saltness is due

to the earth. Just as water strained through ashes becomes salt, so

the sea owes its saltness to the admixture of earth with similar

properties.

We must now consider the facts which prove that the sea cannot