Now is the place, meseems, in these affairs To prove for thee this too: nothing corporeal Of its own force can e'er be upward borne, Or upward go--nor let the bodies of flames Deceive thee here: for they engendered are With urge to upwards, taking thus increase, Whereby grow upwards shining grains and trees, Though all the weight within them downward bears. Nor, when the fires will leap from under round The roofs of houses, and swift flame laps up Timber and beam, 'tis then to be supposed They act of own accord, no force beneath To urge them up. 'Tis thus that blood, discharged From out our bodies, spurts its jets aloft And spatters gore. And hast thou never marked With what a force the water will disgorge Timber and beam? The deeper, straight and down, We push them in, and, many though we be, The more we press with main and toil, the more The water vomits up and flings them back, That, more than half their length, they there emerge, Rebounding. Yet we never doubt, meseems, That all the weight within them downward bears Through empty void. Well, in like manner, flames Ought also to be able, when pressed out, Through winds of air to rise aloft, even though The weight within them strive to draw them down. Hast thou not seen, sweeping so far and high, The meteors, midnight flambeaus of the sky, How after them they draw long trails of flame Wherever Nature gives a thoroughfare? How stars and constellations drop to earth, Seest not? Nay, too, the sun from peak of heaven Sheds round to every quarter its large heat, And sows the new-ploughed intervales with light: Thus also sun's heat downward tends to earth. Athwart the rain thou seest the lightning fly; Now here, now there, bursting from out the clouds, The fires dash zig-zag--and that flaming power Falls likewise down to earth. In these affairs We wish thee also well aware of this: The atoms, as their own weight bears them down Plumb through the void, at scarce determined times, In scarce determined places, from their course Decline a little--call it, so to speak, Mere changed trend. For were it not their wont Thuswise to swerve, down would they fall, each one, Like drops of rain, through the unbottomed void; And then collisions ne'er could be nor blows Among the primal elements; and thus Nature would never have created aught.