"And envious age! all substance ye destroy;
"All things your teeth decay; and you consume
"By gradual progress, but by certain death.
"These also, which the elements we call,
"Their varying changes know: lo! I explain
"Their regular vicissitudes,--attend.

"Four elements th' eternal world contains;
"Two, earth and water, which their ponderous weight
"Sinks low; and two, the air and purer fire,
"Void of dense gravity, soar up on high,
"Free, unconfin'd. Though distant far in space,
"Yet from these four are all things form'd, and all
"To them resolve again. The earth dissolv'd
"Melts into liquid dew; more subtile grown
"It passes to the breezes and the air;
"And air again, when in its thinest form,
"Depriv'd of weight, springs to the fires on high.
"Thence retrogade they come, inverting all
"This order: fire is thicken'd to dense air;
"Air into water; water to hard earth;
"Nor aught retains its form. Nature, of things
"Renewer, figures from old figures makes.
"Nought that the world contains (doubt not my truth)
"E'er perishes, but changes; and receives
"An alter'd shape. What to be born we call,
"Is to begin in different guise to seem
"Than what we were; and what we call to die,
"Is but to cease to wear our wonted form.
"Though haply some part hither may be mov'd,
"Some thither, still the aggregate's the same.
"Nor can I think that aught can long endure
"Unalter'd. Soon the primal ages came
"From gold to iron. Quite transform'd is oft
"The state of places. I have seen what once
"Was earth most solid, chang'd to fluid waves.
"Land have I seen from ocean form'd; and shells
"Marine, lie scatter'd distant from all shore:
"Old anchors bury'd in the mountain tops.
"The rush of waters hollow vallies forms
"Where once were plains; and level lie the hills
"Beneath the deluge: dry the marshy ground
"With barren sand becomes; and what was parch'd
"Is soak'd, a marshy fen. Here nature opes
"New fountains; there she closes up the old.
"Rivers have bursted forth, when earthquakes shook
"The globe; some chok'd have disappear'd below.
"Thus Lycus, swallow'd by the yawning earth,
"Bursts far from thence again, another stream:
"The mighty Erasinus, now absorb'd,
"Now flows, to Argive fields again restor'd.
"And Myssus, they relate, who both his stream
"And banks disliking, as Caicus now
"'Twixt others flows. With Am