Lucretius, De Rerum Natura
William Ellery Leonard, Ed.

     And most in autumn is shaken the house of heaven,
The house so studded with the glittering stars,
And the whole earth around- most too in spring
When flowery times unfold themselves: for, lo,
In the cold season is there lack of fire,
And winds are scanty in the hot, and clouds
Have not so dense a bulk. But when, indeed,
The seasons of heaven are betwixt these twain,
The divers causes of the thunderbolt
Then all concur; for then both cold and heat
Are mixed in the cross-seas of the year,
So that a discord rises among things
And air in vast tumultuosity
Billows, infuriate with the fires and winds-
Of which the both are needed by the cloud
For fabrication of the thunderbolt.
For the first part of heat and last of cold
Is the time of spring; wherefore must things unlike
Do battle one with other, and, when mixed,
Tumultuously rage. And when rolls round
The latest heat mixed with the earliest chill-
The time which bears the name of autumn- then
Likewise fierce cold-spells wrestle with fierce heats.
On this account these seasons of the year
Are nominated "cross-seas."- And no marvel
If in those times the thunderbolts prevail
And storms are roused turbulent in heaven,
Since then both sides in dubious warfare rage
Tumultuously, the one with flames, the other
With winds and with waters mixed with winds.