Oft makes a noise in the great clouds on high.
For the great mountains of the thunderclouds
Are broken, pressed together by the wind,
And crushed into a narrow space, and mixed with hail.
Lightning occurs likewise when clouds colliding
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Have struck out many seeds of fire, as stone
Strikes stone or iron; then also light leaps out
When stone is struck and scatters sparks of fire.
Our ears receive the sound of thunder later
Than our eyes see the lightning, for this reason;
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Things always come more slowly to the ears
Than to the eyes; as this example shows:
If in the distance you observe a man
Felling a tall tree with twin-bladed axe
You see the stroke before the sound of it
Reaches your ears; so also we see lightning
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Before we hear the thunder, which is produced
At the same time as the fire, and by the same cause,
Born of the same collision of the clouds.
Here is another way in which the clouds
Bathe all the landscape in a fleeting light
As the storm flashes with its quivering stroke.
When wind has entered a cloud and whirling round
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Has made the cloud condense around the hollow,
As I explained before, it becomes hot
With its own motion, as you see everything
Grows burning hot with motion; leaden bullets
Melt as they spin in a long flight through the air.
So when the black cloud by the burning wind
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Has been split up, the sudden violent pressure
Makes it shoot out the seeds of heat, and these
Produce the winking flashes of bright flame.
Then the sound follows, coming to the ears
More slowly than the light comes to our eyes.
This happens, you must understand, when clouds are thick
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And are piled high, one cloud upon another,
By an amazing force. Don’t be misled
Because observing from below we see
More easily their wide expanse spread out
Than the great mighty mass piled high above.
Take note then, when you see clouds like mountains
Carried before the winds across the sky,
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Or when you see them on the mountain tops
Piled high, one on another, pressing down
And lying still, with all the winds at rest,
Then you will recognize their mighty mass,
And see great caverns fashioned in them
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With beetling crags, and when a storm builds up
Winds fill them, and imprisoned in the clouds
They vent their indignation with a roar,
And growl like angry beasts shut up in cages;
This way and that they fill the clouds with din,
And circle round and round trying to escape;
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They roll the seeds of fire out of the clouds
And mass them together, and in the hollow furnace
They spin a circling flame, until at last
They burst the cloud, and blaze into the sky.
And also there’s another reason why
That rushing golden gleam of liquid fire
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Darts down to earth. It is that the clouds themselves
Must contain very many seeds of fire.
For when they are entirely free of moisture
Mostly their colour is flaming and shining bright.
Indeed from the sun’s light they must receive
Many such seeds, so with good cause they blush
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And pour out fires. These therefore, when the wind
Has driven them together and compressed them,
Squeeze out and then eject the seeds of fire
Which make the colours of the lightning-flash.
Lightning occurs also when in the sky
The clouds are thinning out, for when the wind
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Gently disperses them as they move on
And dissolves them, then the seeds that make the lightning
Must fall perforce; but then the lightning comes
Noiseless, and without the hideous crash and terror.
I now discuss the nature of thunderbolts.
This the strokes show, and branding marks of heat,
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And the holes breathing noxious fumes of sulphur.
These are the marks of fire, not wind or rain.
Besides, they often set roofs alight, and flame
Gains quick dominion all inside the houses.
This fire, my friend, the thinnest of all fires,
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Nature has made of atoms so small and swift
That nothing in the world can stand against it.
The thunderbolt passes through walls of buildings
As sounds and voices do, through stone, through bronze,
And in an instant melts both bronze and gold.
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And wine inside a vessel suddenly
It makes evaporate, though the jar remains intact;
Doubtless because, as the heat reaches it,
It loosens the fabric of the earthenware
And makes it porous, then entering the jar
It quickly dissolves the atoms of wine and scatters them.
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And this we see the sun can never do
In an age, however strong its flashing heat.
So much more mobile and more masterful
Is the strong power of the thunderbolt.
And now, how they are made and have such power
That with a stroke they can split towers asunder,
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Overturn houses, tear out beams and rafters,
Move monuments of men, struck down and shattered,
Rob human beings of life and slaughter cattle,
And all else of this kind, by what strange power
They work, I’ll tell, and delay you no more with promises.
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We must believe that thunderbolts are made
From thick clouds piled up high; they never strike
From a clear sky or thin layer of cloud.
The facts themselves make clear without a doubt
That at a time of thunderstorms clouds mass together
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Everywhere through the air, so that we think
That all the darkness out of Acheron
Has filled the mighty caverns of the sky.
So dark, beneath the hideous night of cloud,
The face of fear hangs over us above,
When storm begins to forge the thunderbolts.
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And very often too across the sea
A black cloud falls, like pitch poured from the sky,
Loaded with darkness from afar, and draws with it
A black storm big with thunderbolts and blasts
Filled to the brim itself with wind and fire,
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So that on land also men shiver and seek shelter.
From this we must infer that thunderstorms
Stretch high above our heads. For so much blackness
Could never overwhelm the earth unless
A multitude of clouds piled high on clouds
Built up above us, blotting out the sun.
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Nor could there fall that torrent of the rain
That makes the rivers flood and drowns the fields
If ether were not full of clouds piled high.
So everything is full of winds and fires
And thunderclaps and lightning everywhere.
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For indeed I have shown above that hollow clouds
Must contain very many seeds of fire
And must receive many from the sun’s hot rays.
Therefore, when the same wind that has driven them
Into one place together, has squeezed out
Many seeds of fires, and in so doing itself
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Has intermingled with the fire, the whirlwind
Finds its way in, whirls round in the narrow space
And in the hot furnace sharpens the thunderbolt.
For the wind is kindled in two ways: by the heat
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Of its own motion, and by contact with the fire.
Next when the wind has reached a mighty heat
And the strong impulse of the fire has entered,
The thunderbolt, now as it were ripe, cleaves through
The cloud by a sudden blow, and the heat, shot out,
Lights all the place beneath with flashing flames.
A deep roar follows, such that the vault of heaven
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Seems to be sundered apart and falling on us.
A violent tremor now assails the earth
And murmurs roll about the sky; for then
Almost the whole storm quivers with the shock
And roars and crashes. Rain then, heavy and full,
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Follows the shock, so that the whole ether
Seems to be turned to rain, and teeming down
Recalls again the universal Flood.
So much the bursting cloud and raging wind
Pour out when the sound flies from the flaming stroke.
Sometimes also a powerful wind outside
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Falls on a cloud pregnant with a ripe thunderbolt.
It bursts it, and at once that fiery whirlwind falls
Which we name thunderbolt in our native tongue.
And this can strike in various directions,
Depending on the impulse given to it.
Sometimes also a wind that has no fire
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Kindles nevertheless on its long flight through space;
It loses on its course a number of bodies
Too large to keep up with it through the air,
And scrapes together from the air itself
And carries with it other tiny bodies
That mixed with it make fire as it flies,
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In much the same way as a leaden bullet
Often grows hot in flight, when throwing off
The seeds of cold it catches fire in the air.
Sometimes also a blow produces fire,
When a cold wind launched without fire has struck.
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Doubtless because when it has struck a violent blow
Elements of heat can flow together
Both from the wind itself and at the same time
From the object receiving the blow, as fire flies out
When stone is struck with iron, and the fire comes
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No whit the less because the iron is cold.
So also a thing must take fire from a thunderbolt
If it be fit and suitable for flame.
And no wind ever can be utterly
And absolutely cold, if from above
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So powerful a force has driven it.
If it has not caught fire on its course,
When it arrives it must be warm and mixed with heat.
The speed and violent stroke of thunderbolts
And the swift fall with which they cleave the sky
Have this as their cause: a force within the clouds,
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First everywhere aroused, accumulating
Takes on a mighty energy of movement.
Then when the cloud cannot hold the growing impetus
The force explodes, and flies with wondrous speed
Like missiles hurled from powerful catapults.
Moreover, it consists of elements
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Both small and smooth, so that it is not easy
For anything to counter such a substance.
For it flies in between and penetrates
Through narrow passages, therefore few obstacles
Can check it or delay it as it comes;
And this is why it falls with flight so swift.
Again, while all weights naturally possess
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A downward momentum, when a blow is added
The speed is doubled, and the first impulse
Grows heavier, so that with greater speed and strength
It shatters whatever delays it on its course.
Again, the momentum of its lengthy flight
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Must give it ever-growing speed, increasing
As it falls, and this augments its mighty power
And strengthens the blow. It causes all its atoms
To move straight forward to a single point
And throws them together as they flow into that path.
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It may perhaps draw from the air itself
In the course of its flight certain particles
Which by their impact set its speed ablaze.
It passes through things without harming them,
And leaves many things intact after its transit,
Because the fluid fire goes through the pores.
And many it transfixes, when its atoms
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Strike upon other atoms that form a joint.
It readily dissolves bronze and in an instant
Melts gold, because the atoms of which it is made
Are small and smooth and therefore easily
Make their way in, and having got in, at once
Untie all knots and loosen every bond.
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In autumn thunder shakes the house of heaven,
Studded with shining stars, more often, and shakes the earth,
And also when springtime opens with its flowers.
For in the cold fires are few, and in the heat
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The winds fail and clouds are not so thick.
So when the season stands between the two
Then all the various causes of thunderbolts
Combine and flow together in the sky.
For then the year’s rough straits mix cold and heat
(And a cloud needs both to make a thunderbolt),
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So discord comes and with a mighty tumult
And fire and wind the heavens rage and swell.
For the first time of heat is the last of cold,
That is the spring. So battle must be joined
With fray embroiled between things unalike.
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And when the last heat mixed with early cold
Comes round, to which we give the name of autumn,
Here also bitter winter fights with summer.
Therefore these must be named the straits of the year,
And it’s no wonder if these seasons produce
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Thunderbolts in abundance, and a whirling storm
Forms in the sky, since war everywhere
Rocks it on two fronts, on the one side flames
And on the other wind and water mixed.
Thus the true nature of the thunderbolt
Can now be understood, and how it works;
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Not by unrolling scrolls of Tuscan charms
To search in vain the hidden minds of gods
And ask them whence the flying fire has come
Or to what other quarter of the sky
It went, and in what way it penetrated
Through walls of buildings, and having worked its will
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Inside, made its way out again, or ask what harm
The stroke of a thunderbolt from heaven can do.
If Jupiter and other gods, my friend,
Shake with appalling din the realms of heaven,
And shoot their fire where each one wants to aim,
Why do they not arrange that when a man
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Is guilty of some abominable crime
He’s struck, and from his breast transfixed breathes out
Hot flames, a bitter lesson to mankind?
Why is a man of conscience free from stain
Engulfed in flames, all innocent, suddenly
Seized by a fiery whirlwind from the sky?
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Why do they waste their pains shooting at deserts?
Or are they merely practising their aim
And strengthening their muscles? Why do they allow
The Father’s bolt to be blunted on the ground?
Why does he allow this himself, and not keep it
For his enemies? And why does Jupiter
Never when the sky is cloudless everywhere
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Launch bolts upon the earth and sound his thunder?
Or does he wait until the clouds have formed
And then himself descend down into them
To aim his weapon from a shorter range?
What is his object when he strikes the sea?
Has he some grudge against the waves and all
The liquid mass of water and swimming plains?
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And if he wants us to beware the stroke
Why is he loth to let us see it coming?
But if he wants to crush us unawares
Why does he thunder from the same direction
And put us on our guard? Why does he first
Summon the darkness, with its roars and growls?
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And can you possibly believe he shoots
In many directions simultaneously?
Or would you dare to say this never happens,
Never many strikes at the same time?
In fact this often occurs, and it must be
That just as rain-showers fall in many places
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So at one time fall many thunderbolts.
Lastly, why does he wreck the holy shrines of gods
And his own glorious habitations
With hostile thunderbolt? Why does he smash
The noble images of gods, and dishonour
His own fine statues with a violent wound?
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Why does he mostly strike high ground, why do we see
The signs of fire most often on the mountain tops?
From what has been said, it is easy to understand
Those whirlwinds which the Greeks name from their nature
Presters, and how they come from above into the sea.
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It sometimes happens that a kind of column
Is let down from the sky into the sea.
The waters boil round it, lashed by furious winds,
And any ships caught in this mighty tumult
Find themselves storm-tossed, in the greatest danger.
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This happens when sometimes a powerful wind
On the Nature of the Universe (Oxford World’s Classics) Page 27
