Lucretius, De Rerum Natura
William Ellery Leonard, Ed.

     In chief, men marvel nature renders not
Bigger and bigger the bulk of ocean, since
So vast the down-rush of the waters be,
And every river out of every realm
Cometh thereto; and add the random rains
And flying tempests, which spatter every sea
And every land bedew; add their own springs:
Yet all of these unto the ocean's sum
Shall be but as the increase of a drop.
Wherefore 'tis less a marvel that the sea,
The mighty ocean, increaseth not. Besides,
Sun with his heat draws off a mighty part:
Yea, we behold that sun with burning beams
To dry our garments dripping all with wet;
And many a sea, and far out-spread beneath,
Do we behold. Therefore, however slight
The portion of wet that sun on any spot
Culls from the level main, he still will take
From off the waves in such a wide expanse
Abundantly. Then, further, also winds,
Sweeping the level waters, can bear off
A mighty part of wet, since we behold
Oft in a single night the highways dried
By winds, and soft mud crusted o'er at dawn.
Again, I've taught thee that the clouds bear off
Much moisture too, up-taken from the reaches
Of the mighty main, and sprinkle it about
O'er all the zones, when rain is on the lands
And winds convey the aery racks of vapour.
Lastly, since earth is porous through her frame,
And neighbours on the seas, girdling their shores,
The water's wet must seep into the lands
From briny ocean, as from lands it comes
Into the seas. For brine is filtered off,
And then the liquid stuff seeps back again
And all re-poureth at the river-heads,
Whence in fresh-water currents it returns
Over the lands, adown the channels which
Were cleft erstwhile and erstwhile bore along
The liquid-footed floods.