No More Learning

For sometimes, too, it chances that the clouds
Cannot together crash head-on, but rather
Move side-wise and with motions contrary
Graze each the other's body without speed,
From whence that dry sound grateth on our ears,
So long drawn-out, until the clouds have passed
From out their close positions.

And, again,
In following wise all things seem oft to quake
At shock of heavy thunder, and mightiest walls
Of the wide reaches of the upper world
There on the instant to have sprung apart,
Riven asunder, what time a gathered blast
Of the fierce hurricane hath all at once
Twisted its way into a mass of clouds,
And, there enclosed, ever more and more
Compelleth by its spinning whirl the cloud
To grow all hollow with a thickened crust
Surrounding; for thereafter, when the force
And the keen onset of the wind have weakened
That crust, lo, then the cloud, to-split in twain,
Gives forth a hideous crash with bang and boom.
No marvel this; since oft a bladder small,
Filled up with air, will, when of sudden burst,
Give forth a like large sound.

There's reason, too,
Why clouds make sounds, as through them blow the winds:
We see, borne down the sky, oft shapes of clouds
Rough-edged or branched many forky ways;
And 'tis the same, as when the sudden flaws
Of north-west wind through the dense forest blow,
Making the leaves to sough and limbs to crash.
It happens too at times that roused force
Of the fierce hurricane to-rends the cloud,
Breaking right through it by a front assault;
For what a blast of wind may do up there
Is manifest from facts when here on earth
A blast more gentle yet uptwists tall trees
And sucks them madly from their deepest roots.
Besides, among the clouds are waves, and these
Give, as they roughly break, a rumbling roar;
As when along deep streams or the great sea
Breaks the loud surf. It happens, too, whenever
Out from one cloud into another falls
The fiery energy of thunderbolt,
That straightaway the cloud, if full of wet,
Extinguishes the fire with mighty noise;
As iron, white from the hot furnaces,
Sizzles, when speedily we've plunged its glow
Down the cold water. Further, if a cloud
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
Is by their strokes made manifest and by
The brand-marks of their searing heat on things,
And by the scorched scars exhaling round
The heavy fumes of sulphur. For all these
Are marks, O not of wind or rain, but fire.
Again, they often enkindle even the roofs
Of houses and inside the very rooms
With swift flame hold a fierce dominion.
Know thou that nature fashioned this fire
Subtler than fires all other, with minute
And dartling bodies,--a fire 'gainst which there's naught
Can in the least hold out: the thunderbolt,
The mighty, passes through the hedging walls
Of houses, like to voices or a shout,--
Through stones, through bronze it passes, and it melts
Upon the instant bronze and gold; and makes,
Likewise, the wines sudden to vanish forth,
The wine-jars intact,--because, ye see,
Its heat arriving renders loose and porous
Readily all the wine--jar's earthen sides,
And winding its way within, it scattereth
The elements primordial of the wine
With speedy dissolution--process which
Even in an age the fiery steam of sun
Could not accomplish, however puissant he
With his hot coruscations: so much more
Agile and overpowering is this force.

*****

Now in what manner engendered are these things,
How fashioned of such impetuous strength
As to cleave towers asunder, and houses all
To overtopple, and to wrench apart
Timbers and beams, and heroes' monuments
To pile in ruins and upheave amain,
And to take breath forever out of men,
And to o'erthrow the cattle everywhere,--
Yes, by what force the lightnings do all this,
All this and more, I will unfold to thee,
Nor longer keep thee in mere promises.

The bolts of thunder, then, must be conceived
As all begotten in those crasser clouds
Up-piled aloft; for, from the sky serene
And from the clouds of lighter density,
None are sent forth forever. That 'tis so
Beyond a doubt, fact plain to sense declares:
To wit, at such a time the densed clouds
So mass themselves through all the upper air
That we might think that round about all murk
Had parted forth from Acheron and filled
The mighty vaults of sky--so grievously,
As gathers thus the storm-clouds' gruesome might,
Do faces of black horror hang on high--
When tempest begins its thunderbolts to forge.
Besides, full often also out at sea
A blackest thunderhead, like cataract
Of pitch hurled down from heaven, and far away
Bulging with murkiness, down on the waves
Falls with vast uproar, and draws on amain
The darkling tempests big with thunderbolts
And hurricanes, itself the while so crammed
Tremendously with fires and winds, that even
Back on the lands the people shudder round
And seek for cover. Therefore, as I said,
The storm must be conceived as o'er our head
Towering most high; for never would the clouds
O'erwhelm the lands with such a massy dark,
Unless up-builded heap on lofty heap,
To shut the round sun off. Nor could the clouds,
As on they come, engulf with rain so vast
As thus to make the rivers overflow
And fields to float, if ether were not thus
Furnished with lofty-piled clouds.