Lucretius, De Rerum Natura
William Ellery Leonard, Ed.

Now come, and what the law of earthquakes is
Hearken, and first of all take care to know
That the under-earth, like to the earth around us,
Is full of windy caverns all about;
And many a pool and many a grim abyss
She bears within her bosom, ay, and cliffs
And jagged scarps; and many a river, hid
Beneath her chine, rolls rapidly along
Its billows and plunging boulders. For clear fact
Requires that earth must be in every part
Alike in constitution. Therefore, earth,
With these things underneath affixed and set,
Trembleth above, jarred by big down-tumblings,
When time hath undermined the huge caves,
The subterranean. Yea, whole mountains fall,
And instantly from spot of that big jar
There quiver the tremors far and wide abroad.
And with good reason: since houses on the street
Begin to quake throughout, when jarred by a cart
Of no large weight; and, too, the furniture
Within the house up-bounds, when a paving-block
Gives either iron rim of the wheels a jolt.
It happens, too, when some prodigious bulk
Of age-worn soil is rolled from mountain slopes
Into tremendous pools of water dark,
That the reeling land itself is rocked about
By the water's undulations; as a basin
Sometimes won't come to rest until the fluid
Within it ceases to be rocked about
In random undulations.
     And besides,
When subterranean winds, up-gathered there
In the hollow deeps, bulk forward from one spot,
And press with the big urge of mighty powers
Against the lofty grottos, then the earth
Bulks to that quarter whither push amain
The headlong winds. Then all the builded houses
Above ground- and the more, the higher up-reared
Unto the sky- lean ominously, careening
Into the same direction; and the beams,
Wrenched forward, over-hang, ready to go.
Yet dread men to believe that there awaits
The nature of the mighty world a time
Of doom and cataclysm, albeit they see
So great a bulk of lands to bulge and break!
And lest the winds blew back again, no force
Could rein things in nor hold from sure career
On to disaster. But now because those winds
Blow back and forth in alternation strong,
And, so to say, rallying charge again,
And then repulsed retreat, on this account
Earth oftener threatens than she brings to pass
Collapses dire. For to one side she leans,
Then back she sways; and after tottering
Forward, recovers then her seats of poise.
Thus, this is why whole houses rock, the roofs
More than the middle stories, middle more
Than lowest, and the lowest least of all.