Celestial Phenomena

1. Thunder may be caused:

• a. when clouds clash together face to face; (being of a texture neither close nor rare);

First of all the blue of the sky is shaken by thunder because the clouds in high heaven, scudding aloft, clash together when the winds are fighting in combat.

For the sound comes not from a clear quarter of the sky, but wherever the clouds are massed in denser host, from there more often comes the roar and its loud rumbling. Moreover, the clouds cannot be of so dense a body as are stocks and stones, nor yet so thin as are mists and flying smoke. For either they were bound to fall dragged down by their dead weight, as do stones, or like smoke they could not hold together or keep within them chill snow and showers of hail.

• b. when they scrape along one another’s sides, and make a noise like wind in a flapping awning or paper; Again, they give forth a sound over the levels of the spreading firmament, as often an awning stretched over a great theatre gives a crack, as it tosses among the posts and beams; sometimes, too, it rages madly, rent by the boisterous breezes, and imitates the rending noise of sheets of paper—for that kind of sound too you may recognize in the thunder—or else a sound as when the winds buffet with their blows and beat through the air a hanging garment or flying papers. For indeed it also comes to pass at times that the clouds cannot so much clash together face to face, but rather pass along the flank, moving from diverse quarters, and slowly grazing body against body; and then the dry sound brushes upon the ears, and is drawn out long, until they have issued from their close quarters.

(c) when wind is caught in a cloud and suddenly bursts it;In this way, too, all things seem often to tremble with heavy thunder, and the great walls of the containing world to be torn apart suddenly and leap asunder, when all at once a gathered storm of mighty wind has twisted its way into the clouds, and, shut up there with its whirling eddy, constrains the cloud more and more on all sides to hollow itself out with body thickening all around; and then, when the force and fierce onslaught of the wind have weakened it, it splits and makes a rending crash with a frightful cracking sound. Nor is that strange, when a little bladder full of air often likewise gives forth a little noise, if suddenly burst.

(d) when wind blows through the clouds, like a forest;There is also another way, when winds blow through clouds, whereby they may make a noise. For often we see clouds borne along, branching in many ways, and rough-edged; even as, we may be sure, when the blasts of the north-west blow through a dense forest, the leaves give out a noise and the branches a rending crash.(e) when the wind bursts a cloud open; It comes to pass, too, sometimes, that the force of a mighty wind rushing on tears through the cloud and breaks it asunder with a front attack. For what the blast can do there is shown by things clear to see here on earth, where the wind is gentler and yet it tears out and sucks up tall trees from their lowest roots. There are, too,(f) when the rainwaves in the clouds break; (g) when lightning, falling from one cloud into another, hisses or waves moving through the clouds, which as it were make a heavy roar in breaking; just as it comes to pass in deep rivers and the great sea, when the tide breaks. This happens too, when the fiery force of the thunderbolt falls from cloud to cloud; if by chance the cloud has received the flame in deep moisture, it straightway slays it with a great noise; just as often iron white-hot from the fiery furnaces hisses, when we have plunged it quickly into cold water.(h) burns the cloud up; Or again, if a drier cloud receives the flame, it is at once fired, and burns with a vast noise; just as if among the laurel-leafed mountains flame were to roam abroad beneath the eddying of the winds, burning them up in its mighty onset; nor is there any other thing which is burnt up by the crackling flame with sound so terrible as the Delphic laurel of Phoebus.(i) when the ice and hail in the clouds crash. Again, often the great cracking of ice and the falling of hail makes a noise in the mighty clouds on high. For when the wind packs them tight, the mountains of storm-clouds, frozen close and mingled with hail, break up.

2. Lightning may be caused (a) when two clouds colliding strike fire. (We see it before we hear the thunder, because light travels faster than sound.)It lightens likewise, when the clouds at their clashing have struck out many seeds of fire; just as if stone should strike on stone or on iron; for then, too, a flash leaps out and scatters abroad bright sparks of fire. But it comes to pass that we receive the thunder in our ears after our eyes perceive the lightning, because things always move more slowly n to the ears than things which stir the eyes. That you may learn from this too; if you see some one far off cutting down a giant tree with double-edged axe, it comes to pass that you see the stroke before the blow resounds in your ear; even so we see the lightning too before we hear the thunder, which is sent abroad at the same moment with the flash, from a like cause, yea, born indeed from the same collision.

In this manner, too, the clouds colour places with leaping light, and the storm lightens with quivering dart.(b) when wind shut in a cloud whirls itself round till it ignites. When wind has come within a cloud, and moving there has, as I have shown before, made the hollow cloud grow thick, it grows hot with its own swift movement; even as you see all things become hot and catch fire through motion, yea, even a ball of lead too, whirling in a long course, will melt. And so when this heated wind has torn through the black cloud, it scatters abroad seeds of fire, as though struck out all at once by force, and they make the pulsing flashes of flame; thereafter follows the sound, which reaches our ears more slowly than things which come to the light of our eyes. This, we must know,This happens in high-piled masses of clouds: comes to pass in thick clouds, which are also piled up high one on the other in wondrous slope; lest you be deceived because we below see how broad they are rather than to what a height they stand piled up. For do but look, when next the winds carry athwart the air clouds in the semblance of mountains, or when you see them heaped along a mighty mountain-range one above the other, pressing down from above, at rest in their appointed place, when the winds on all sides are in their graves. Then you will be able to mark their mighty mass, and to see their caverns built up, as it were, of hanging rocks: and when the storm has risen and the winds have filled them,the wind collects all the seeds of fire in one and then bursts through the cloud; with loud roar they chafe prisoned in the clouds, and threaten like wild beasts in cages; now from this side, now from that they send forth their roaring through the clouds, and seeking an outlet they move round and round, and roll together the seeds of fire from out the clouds, and so drive many into a mass and set the flame whirling within the hollow furnaces, until they have rent asunder the cloud and flashed blazing out.

(c) when the fire in the clouds themselves is driven out as they collide,For this cause, too, it comes to pass that this swift golden tinge of liquid fire flies down to earth, because it must needs be that the clouds have in themselves very many seeds of fire; for indeed when they are without any moisture, they have for the most part a bright and flaming colour. For verily it must needs be that they catch many such from the sun’s light, so that with reason they are red, and pour forth their fires. When then the wind as it drives them has pushed and packed and compelled them into one spot, they squeeze out and pour forth the seeds which make the colours of flame to flash. It lightens likewise,(d) or falls naturally as they break: this causes sheet lightning. also when the clouds of heaven grow thin. For when the wind lightly draws them asunder as they move, and breaks them up, it must needs be that those seeds, which make the flash, fall out unbidden. Then it lightens without hideous alarm, without noise, and with no uproar.

3. Thunderbolts are of fiery nature,For the rest, with what kind of nature the thunderbolts are endowed, is shown by the blows and the burned markings of their heat and the brands which breathe out noisome vapours of sulphur. For these are marks of fire, not of wind nor rain. Moreover, often too they set the roofs of dwellings on fire, and with swiftly-moving flame play the tyrant even within the houses.and formed of exceedingly subtle fire, as we may see from their effects. This fire, you must know, nature has fashioned most subtle of all subtle fires, of tiny swift-moving bodies—a flame to which nothing at all can be a barrier. For the strong thunderbolt can pass through the walls of houses, even as shouts and cries, can pass through rocks, through things of bronze, and in a moment of time can melt bronze and gold; likewise it causes wine in an instant to flee away, though the vessels be untouched, because, we may be sure, its heat as it comes easily loosens all around and makes rarefied the porcelain of the vessel, and finding its way right into the wine, with quick motion dissolves and scatters the first-beginnings of the wine. Yet this the heat of the sun is seen to be unable to bring about in a long age, though it has such exceeding strength in its flashing blaze. So much swifter and more masterful is this force of the thunderbolt.

We must explain their power and action.Now in what manner they are fashioned and made with such force that they can with their blow burst open towers, overthrow houses, pluck up beams and joists, and upset and 1 the monuments of men, take the life from men, lay low the flocks on every side; by what force they are able to do all other things of this sort, I will set forth, nor keep thee longer waiting on my promise.

They are created only when clouds are densely piled on high,We must suppose that thunderbolts are produced from thick clouds, piled up on high; for none are ever hurled abroad from the clear sky or from clouds of slight thickness. For without doubt clear-seen facts show that this comes to pass; at such times clouds grow into a mass throughout all the air, so that on all sides we might think that all darkness has left Acheron and filled the great vault of the sky; so terribly, when the noisome night of clouds has gathered together, do the shapes of black fear hang over us on high, when the storm begins to forge its thunderbolts. Moreover,as we see them sometimes over the sea. very often a black storm-cloud too, over the sea, like a stream of pitch shot from the sky, falls upon the waters, laden with darkness afar off, and draws on a black storm big with thunderbolts and hurricanes, itself more than all filled full with fires and winds in such wise that even on land men shudder and seek for shelter. Thus then above our head must we suppose the storm is raised high. For indeed they would not shroud the earth in such thick gloom, unless there were many clouds built up aloft on many others, shutting out all sunlight; nor when they come could they drown it in such heavy rain, as to make the rivers overflow and the fields swim, unless the ether were filled with clouds piled up on high.Such clouds are full of wind and fire. Here, then, all is full of winds and fires; for this cause all around come crashings and lightnings. For verily I have shown ere now that the hollow clouds possess very many seeds of heat, and many they must needs catch from the sun’s rays and their blaze.The wind with the fire forms an eddy, Therefore, when the same wind, which drives them together, as it chances, into some one place, has squeezed out many seeds of heat, and at the same time has mingled itself with this fire, an eddy finds its way in there and whirls round in a narrow space and sharpens the thunderbolt in the hot furnaces within. For it is kindled in two ways, both when it grows hot with its own swift motion, and from contact with the fire.which bursts the cloud and comes out as a thunderbolt, bringing with it thunder, lightning, storm, and rain. Next, when the force of the wind has grown exceeding hot, and the fierce onset of the fire has entered in, then the thunderbolt, full-forged, as it were, suddenly rends through the cloud, and shot out is borne on flooding all places with its blazing light. In its train follows a heavy crash, so that the quarters of the sky above seem to be burst asunder on a sudden and crush us. Then a trembling thrills violently through the earth, and rumblings race over the high heaven; for then all the storm is shaken into trembling and roarings move abroad. And from this shock follows rain, heavy and abundant, so that all the air seems to be turned into rain, and thus falling headlong to summon earth back to deluge: so great a shower is shot forth with the rending of the cloud and the hurricane of wind, when the thunderclap flies forth with its burning blow. At times,Sometimes the cloud is burst by an external wind. too, the rushing force of wind falls from without upon the cloud hot with its new-forged thunderbolt; and when it has rent the cloud, straightway there falls out that fiery eddy which we call by the name our fathers gave it, the thunderbolt. The same thing happens in other directions, wherever its force has carried it. It comes to pass, too,Sometimes the wind itself ignites in its course, sometimes that the force of the wind, starting without fire, yet catches fire on its course and its long wandering, as it loses in its journey, while it is approaching, certain large bodies, which cannot like the others make their way through the air; and gathering other small bodies from the air itself it carries them along, and they mingling with it make fire in their flight;like a flying ball of lead. in no other way than often a ball of lead grows hot in its course, when dropping many bodies of stiff cold it has taken in fire in the air.Or the blow of wind on cloud may create fire, It comes to pass, too, that the force of the very blow rouses fire, when the force of the wind, starting cold without fire, has struck its stroke; because, we may be sure, when it has hit with violent blow, particles of heat can stream together out of the wind itself, and at the same time from the thing which then receives the blow; just as,like iron striking on stone; when we strike a stone with iron, fire flies out, nor do the seeds of blazing heat rush together any more slowly at its blow, because the force of the iron is cold. Thus then a thing is bound to be kindled by the thunderbolt too, if by chance it is made fit and suitable for flame.for the wind itself is not wholly cold. Nor must we rashly think that the force of the wind can be wholly and utterly cold, when it has been discharged with such force on high; rather, if it is not beforehand on its journey kindled with fire, yet it arrives warmed and mingled with heat.

The velocity of the thunderbolt is caused (a) by the impulse with which it is shot from the cloud;But the great speed of the thunderbolt and its heavy blow comes to pass, yea, the thunderbolts always run their course with swift descent, because their force unaided is first of all set in motion in each case, and gathers itself within the clouds, and conceives a great effort for starting; and then, when the cloud has not been able to contain the growing strength of its onset, its force is squeezed out, and so flies with wondrous impulse even as the missiles which are borne on, when shot from engines of war. Remember,(b) because it is made of small smooth particles; too, that it is made of small and smooth particles, nor is it easy for anything to withstand such a nature: for it flies in between and pierces through the hollow passages, and so it is not clogged and delayed by many obstacles, and therefore it flies on falling with swift impulse.(c) because gravitation is augmented by a blow; Again, because all weights by nature always press downwards, but when a blow is given as well, their swiftness is doubled and the impulse grows stronger, so that the more violently and quickly does it scatter with its blows all that impedes it, and continues on its journey. Once again,(d) because in its long course it overcomes internal vibration. because it comes with long-lasting impulse, n it is bound to gather speed ever more and more, which grows as it moves, and increases its strong might and strengthens its stroke. For it brings it about that the seeds of the thunderbolt are one and all carried in a straight line, as it were towards one spot, driving them all as they fly into the same course.(e) perhaps because it is helped by particles gathered from the air. It can penetrate and dissolve things, because it impinges on them just where their atoms are joined. It may chance too that as it goes it picks up certain bodies even from the air, which kindle its swiftness by their blows. And it passes through things without harming them, and goes right through many things, and leaves them whole, because the liquid fire flies through the pores. And it pierces through many things, since the very bodies of the thunderbolt have fallen on the bodies of things just where they are interlaced and held together. Moreover, it easily melts bronze and in an instant makes gold to boil, because its force is fashioned delicately of tiny bodies and of smooth particles, which easily force a way within, and being there at once loose all the knots and slacken the bonds.Thunderbolts occur mostly in spring and autumn, because then the various elements needful for their composition most coincide. And most in autumn is the house of heaven, set with shining stars, shaken on all sides and all the earth, and again when the flowery season of spring spreads itself abroad. For in the cold fires are lacking, and in the heat winds fail, nor are clouds of so dense a body. And so when the seasons of heaven stand midway between the two, then all the diverse causes of the thunderbolt meet together. For the narrow channel n of the year of itself mingles cold and heat—of both of which the cloud has need for the forging of thunderbolts—so that there is a wrangling among things, and with great uproar the air rages and tosses with fires and winds. For the first part of the heat is the last of the stiff cold, that is the spring season: wherefore it must needs be that different elements, mingled with one another, make battle and turmoil. And again, when the last heat rolls on mingled with the first cold—the season which is called by the name of autumn—then, too, keen winters do battle with summers. For this cause these seasons must be called the narrow channels of the year, nor is it strange, if at that time thunderbolts come most often, and a turbulent tempest is gathered in the sky, since from either side is roused the turmoil of doubtful battle, on the one side with flames, on the other with mingled wind and wet.

The thunderbolt is no sign of divine wrath.This is the way to see into the true nature of the thunderbolt, and to perceive by what force it does each thing, and not by unrolling vainly the Tyrrhenian prophecies n and seeking out tokens of the hidden purpose of the gods, marking whence came the winged flash, or to what quarter it departed hence, in what manner it won its way through walled places, and how after tyrant deeds it brought itself forth again, or what harm the stroke of the thunderbolt from heaven can do.If so, why do the gods hit the innocent and leave the guilty? But if Jupiter n and the other gods shake the shining quarters of heaven with awe-inspiring crash and hurl the fire to whatever point each may will, why do they not bring it about that those who have not guarded against some sin from which men hide their face, are struck and reek of the flames of lightning, with their breast pierced through, a sharp lesson to mortals? why rather is one conscious of no foul guilt wrapt and entangled, all innocent, in the flames, caught up in a moment in the fiery whirlwind of heaven?Why waste their strokes on deserts? why again do they aim at waste places and spend their strength for naught? are they then practising their arms and strengthening their muscles? and why do they suffer the father’s weapon to be blunted on the earth? why does he himself endure it and not spare it for his foes? Again,Why not hurl them from the clear sky? why does Jupiter never hurl his thunderbolt to earth and pour forth his thunders when the heaven is clear on all sides? Or, as soon as the clouds have come up, does he himself then come down into them, so that from them he may direct the blow of his weapon from close at hand?Why at the sea? Does Jupiter wish us to beware or not? Again, with what purpose does he throw into the sea? what charge has he against the waves, the mass of water and the floating fields? Moreover, if he wishes us to beware of the thunderbolt’s stroke, why is he reluctant to let us be able to see its cast? but if he wishes to overwhelm us with the fire when off our guard, why does he thunder from that quarter, so that we can shun it? why does he gather darkness beforehand and rumblings and roarings?How can he hurl many bolts at once? And how can you believe that he hurls his bolts at once to many sides? or would you dare to argue that this has never come to pass, that several strokes were made at one time? Nay, but very often has it happened and must needs happen, that as it rains and showers fall in many regions, so many thunderbolts are fashioned at one time. Lastly,Why destroy his own temples and images? why does he smite asunder the sacred shrines of the gods and his own glorious dwelling-places with hostile bolt? why does he destroy the fair-fashioned idols of the gods and take away their beauty from his images with his furious wound?or scar mountain peaks? And why does he aim mostly at lofty spots, so that we see most traces of his fire on mountain-tops?

4. Waterspouts are causedNext after this, it is easy to learn from these things in what way there come into the sea, shot from on high, what the Greeks from their nature have named fiery presters. n For it comes to pass sometimes that as it were a column let down descends from the sky into the sea, around which the surges boil, violently stirred by breathing blasts, and all ships that are then caught in that turmoil, are harried and come into great danger.when wind cannot break through a cloud but forces it down to meet the sea; This comes to pass sometimes when the force of the wind set in motion cannot burst the cloud it starts to burst, but presses it down, so that it is weighed down like a column from sky to sea, little by little, as though something were being thrust down and stretched out into the waves by a fist and the pushing of an arm above; and when it has rent this cloud asunder, the force of the wind bursts forth thence into the sea and brings to pass a wondrous seething in the waters. For a whirling eddy descends and brings down along with it that cloud of pliant body; and as soon as it has forced it down pregnant on to the levels of ocean, the eddy on a sudden plunges its whole self into the water, and stirs up all the sea with a great roar, constraining it to seethe.or else an eddy gathers clouds about it and drops to the earth. It comes to pass also that an eddy of wind by itself wraps itself in clouds, gathering together seeds of cloud from the air and, as it were, imitates the prester let down from the sky. When this eddy has let itself down to earth and broken up, it vomits forth a furious force of whirlwind and storm. But because this happens but rarely at all, and mountains must needs bar it on land, it is seen more often on a wide prospect of sea, and in an open stretch of sky.

5. Clouds are formed (a) as particles gather in the air in masses gradually growing larger;Clouds gather up, when many bodies as they fly in this upper expanse of heaven have all at once come together—bodies of rougher kind, such as can, though they be but intertwined with slight links, yet grasp and cling to one another. These first of all cause little clouds to form; then these grip hold of one another and flock together, and uniting they grow and are borne on by the winds, until at last a furious tempest has gathered together. It comes to pass,especially round mountain tops, whither they are driven by wind; too, that mountain-tops, the closer they are to the sky, the more at that height do they smoke continually with the thick darkness of a murky cloud, because, when first the clouds form, still thin, before the eyes can see them, the winds carry them and drive them together to the topmost peaks of the mountain. There it comes to pass at last that, gathered now in a greater throng and thickened, they can be seen, and at once they seem to rise into the open sky from the very summit of the mountain. For clear fact and our sense, when we climb high mountains, proclaim that windy regions stretch above. Moreover,(b) as particles of moisture rise from the sea that nature lifts up many such bodies all over the sea is shown by clothes hung out on the shore, when they take in a clinging moisture. Wherefore it is all the more seen that many bodies too can rise to swell the clouds from the salt tossing ocean; for in all their nature these two moistures are akin. Moreover,or from rivers, or even lands; we see clouds and vapour rising from all rivers, and likewise from the very earth which, like a breath, are forced out hence and carried upwards, and curtain the heaven with their darkness, and little by little, as they meet, build up the clouds on high. For the vapour of the starry ether above presses down on them too, and, as it were by thickening, weaves a web of storm-cloud beneath the blue. It happens, too,(c) as particles fly in from outside the world that there come into our sky those bodies from without which make clouds and flying storms. For I have shown that their number is innumerable, and the sum of the deep measureless, and I have set forth with what speed the bodies fly, and how in a moment they are wont to traverse through space that none can tell. So it is not strange if often in a short time storm and darkness cover up sea and land with such great storm-clouds, 1 brooding above, inasmuch as on all sides through all the pores of the ether, and, as it were, through the breathing-holes of the great world all around there is furnished for the particles exit and entrance.

6. Rain is caused (a) because the clouds contain much moisture;Come now, in what manner the rainy moisture gathers together in the high clouds, and how the shower falls shot down upon the earth, I will unfold. First of all it will be granted me that already many seeds of water rise up with the clouds themselves from out of all things, and that both alike grow in this manner, both clouds and all water that is in the clouds, just as our body grows along with its blood, and likewise sweat and all the moisture too that is within the limbs.(b) because it rises into them from the sea and the rivers; Besides, they often take in also much moisture from the sea, just like hanging fleeces of wool, when the winds carry the clouds over the great sea. In like manner moisture from all streams is raised to the clouds.and is then squeezed out by the force of the wind and the mass of the clouds; And when many seeds of waters in many ways have duly come together there, increased from all quarters, the packed clouds are eager to shoot out the moisture for a double cause; for the force of the wind pushes it on and the very mass of the clouds, driven together in greater throng, presses on it and weighs it down from above, and makes the showers stream out.or again, when the clouds are thin, by the sun’s heat. Moreover, when the clouds, too, are thinned by the winds or broken up, smitten by the sun’s heat above, they send out the rainy moisture and drip, even as wax over a hot fire melts and flows in a thick stream.Rain is heavy when the pressure is violent, and long when there is much moisture. But a violent downpour comes to pass, when the clouds are violently pressed by either force, their own mass and the impulse of the wind. Yea, and the rains are wont to hold on long and make a great stay, when many seeds of water are gathered, and clouds piled upon clouds and streaming storms above them are borne on from every quarter, and when the whole earth smoking,The rainbow is caused by the sun shining on the rain. Similarly all meteorological phenomena may be explained. breathes out its moisture. When at such time the sun amid the dark tempest has shone out with its rays full against the spray of the storm-clouds, then among the black clouds stand out the hues of the rainbow.

All other things which grow above and are brought to being above, and which gather together in the clouds, all, yea all of them, snow, winds, hail, chill hoar-frosts, and the great force of ice, that great hardener of waters, the curb which everywhere reins in the eager streams, it is yet right easy to find these out, and to see in the mind in what manner they all come to be and in what way they are brought to being, when you have duly learned the powers that are vouchsafed to the elements.