De Rerum Natura

More dry receive the fire, 'twill suddenly

Kindle to flame and burn with monstrous sound,

As if a flame with whirl of winds should range

Along the laurel-tressed mountains far,

Upburning with its vast assault those trees;

Nor is there aught that in the crackling flame

Consumes with sound more terrible to man

Than Delphic laurel of Apollo lord.

Oft, too, the multitudinous crash of ice

And down-pour of swift hail gives forth a sound

Among the mighty clouds on high; for when

The wind hath packed them close, each mountain mass

Of rain-cloud, there congealed utterly

And mixed with hail-stones, breaks and booms...

. . . . . .

Likewise, it lightens, when the clouds have struck,

By their collision, forth the seeds of fire:

As if a stone should smite a stone or steel,

For light then too leaps forth and fire then scatters

The shining sparks. But with our ears we get

The thunder after eyes behold the flash,

Because forever things arrive the ears

More tardily than the eyes- as thou mayst see

From this example too: when markest thou

Some man far yonder felling a great tree

With double-edged ax, it comes to pass

Thine eye beholds the swinging stroke before

The blow gives forth a sound athrough thine ears:

Thus also we behold the flashing ere

We hear the thunder, which discharged is

At same time with the fire and by same cause,

Born of the same collision.

In following wise

The clouds suffuse with leaping light the lands,

And the storm flashes with tremulous elan:

When the wind hath invaded a cloud, and, whirling there,

Hath wrought (as I have shown above) the cloud

Into a hollow with a thickened crust,

It becomes hot of own velocity:

Just as thou seest how motion will o'erheat

And set ablaze all objects,- verily

A leaden ball, hurtling through length of space,

Even melts. Therefore, when this same wind a-fire

Hath split black cloud, it scatters the fire-seeds,

Which, so to say, have been pressed out by force

Of sudden from the cloud;- and these do make

The pulsing flashes of flame; thence followeth

The detonation which attacks our ears

More tardily than aught which comes along

Unto the sight of eyeballs. This takes place-

As know thou mayst- at times when clouds are dense

And one upon the other piled aloft

With wonderful upheavings- nor be thou

Deceived because we see how broad their base

From underneath, and not how high they tower.

For make thine observations at a time

When winds shall bear athwart the horizon's blue

Clouds like to mountain-ranges moving on,

Or when about the sides of mighty peaks

Thou seest them one upon the other massed

And burdening downward, anchored in high repose,

With the winds sepulchred on all sides round:

Then canst thou know their mighty masses, then

Canst view their caverns, as if builded there

Of beetling crags; which, when the hurricanes

In gathered storm have filled utterly,

Then, prisoned in clouds, they rave around

With mighty roarings, and within those dens

Bluster like savage beasts, and now from here,

And now from there, send growlings through the clouds,

And seeking an outlet, whirl themselves about,

And roll from 'mid the clouds the seeds of fire,

And heap them multitudinously there,

And in the hollow furnaces within

Wheel flame around, until from bursted cloud

In forky flashes they have gleamed forth.

Again, from following cause it comes to pass

That yon swift golden hue of liquid fire

Darts downward to the earth: because the clouds

Themselves must hold abundant seeds of fire;

For, when they be without all moisture, then

They be for most part of a flamy hue

And a resplendent. And, indeed, they must

Even from the light of sun unto themselves

Take multitudinous seeds, and so perforce

Redden and pour their bright fires all abroad.

And therefore, when the wind hath driven and thrust,

Hath forced and squeezed into one spot these clouds,

They pour abroad the seeds of fire pressed out,

Which make to flash these colours of the flame.

Likewise, it lightens also when the clouds

Grow rare and thin along the sky; for, when

The wind with gentle touch unravels them

And breaketh asunder as they move, those seeds

Which make the lightnings must by nature fall;

At such an hour the horizon lightens round

Without the hideous terror of dread noise

And skiey uproar.

To proceed apace,

What sort of nature thunderbolts possess