And tempests, gathering from the earth and sky, Back to the sky and earth absorbed retire-With reason, since there's naught that's fashioned not With body porous.
Furthermore, not all The particles which be from things thrown off Are furnished with same qualities for sense, Nor be for all things equally adapt.
A first ensample: the sun doth bake and parch The earth; but ice he thaws, and with his beams Compels the lofty snows, up-reared white Upon the lofty hills, to waste away;Then, wax, if set beneath the heat of him, Melts to a liquid. And the fire, likewise, Will melt the copper and will fuse the gold, But hides and flesh it shrivels up and shrinks.
The water hardens the iron just off the fire, But hides and flesh (made hard by heat) it softens.
The oleaster-tree as much delights The bearded she-goats, verily as though 'Twere nectar-steeped and shed ambrosia;Than which is naught that burgeons into leaf More bitter food for man. A hog draws back For marjoram oil, and every unguent fears Fierce poison these unto the bristled hogs, Yet unto us from time to time they seem, As 'twere, to give new life. But, contrariwise, Though unto us the mire be filth most foul, To hogs that mire doth so delightsome seem That they with wallowing from belly to back Are never cloyed.
A point remains, besides, Which best it seems to tell of, ere I go To telling of the fact at hand itself.
Since to the varied things assigned be The many pores, those pores must be diverse In nature one from other, and each have Its very shape, its own direction fixed.
And so, indeed, in breathing creatures be The several senses, of which each takes in Unto itself, in its own fashion ever, Its own peculiar object. For we mark How sounds do into one place penetrate, Into another flavours of all juice, And savour of smell into a third. Moreover, One sort through rocks we see to seep, and, lo, One sort to pass through wood, another still Through gold, and others to go out and off Through silver and through glass. For we do see Through some pores form-and-look of things to flow, Through others heat to go, and some things still To speedier pass than others through same pores.
Of verity, the nature of these same paths, Varying in many modes (as aforesaid)Because of unlike nature and warp and woof Of cosmic things, constrains it so to be.
Wherefore, since all these matters now have been Established and settled well for us As premises prepared, for what remains 'Twill not be hard to render clear account By means of these, and the whole cause reveal Whereby the magnet lures the strength of iron.
First, stream there must from off the lode-stone seeds Innumerable, a very tide, which smites By blows that air asunder lying betwixt The stone and iron. And when is emptied out This space, and a large place between the two Is made a void, forthwith the primal germs Of iron, headlong slipping, fall conjoined Into the vacuum, and the ring itself By reason thereof doth follow after and go Thuswise with all its body. And naught there is That of its own primordial elements More thoroughly knit or tighter linked coheres Than nature and cold roughness of stout iron.
Wherefore, 'tis less a marvel what I said, That from such elements no bodies can From out the iron collect in larger throng And be into the vacuum borne along, Without the ring itself do follow after.
And this it does, and followeth on until 'Thath reached the stone itself and cleaved to it By links invisible. Moreover, likewise, The motion's assisted by a thing of aid (Whereby the process easier becomes),-Namely, by this: as soon as rarer grows That air in front of the ring, and space between Is emptied more and made a void, forthwith It happens all the air that lies behind Conveys it onward, pushing from the rear.
For ever doth the circumambient air Drub things unmoved, but here it pushes forth The iron, because upon one side the space Lies void and thus receives the iron in.
This air, whereof I am reminding thee, Winding athrough the iron's abundant pores So subtly into the tiny parts thereof, Shoves it and pushes, as wind the ship and sails.
The same doth happen in all directions forth:
From whatso side a space is made a void, Whether from crosswise or above, forthwith The neighbour particles are borne along Into the vacuum; for of verity, They're set a-going by poundings from elsewhere, Nor by themselves of own accord can they Rise upwards into the air. Again, all things Must in their framework hold some air, because They are of framework porous, and the air Encompasses and borders on all things.
Thus, then, this air in iron so deeply stored Is tossed evermore in vexed motion, And therefore drubs upon the ring sans doubt And shakes it up inside....
. . . . . .
In sooth, that ring is thither borne along To where 'thas once plunged headlong- thither, lo, Unto the void whereto it took its start.
It happens, too, at times that nature of iron Shrinks from this stone away, accustomed By turns to flee and follow. Yea, I've seen Those Samothracian iron rings leap up, And iron filings in the brazen bowls Seethe furiously, when underneath was set The magnet stone. So strongly iron seems To crave to flee that rock. Such discord great Is gendered by the interposed brass, Because, forsooth, when first the tide of brass Hath seized upon and held possession of The iron's open passage-ways, thereafter Cometh the tide of the stone, and in that iron Findeth all spaces full, nor now hath holes To swim through, as before. 'Tis thus constrained With its own current 'gainst the iron's fabric To dash and beat; by means whereof it spues Forth from itself- and through the brass stirs up-The things which otherwise without the brass It sucks into itself. In these affairs Marvel thou not that from this stone the tide Prevails not likewise other things to move With its own blows: for some stand firm by weight, As gold; and some cannot be moved forever, Because so porous in their framework they That there the tide streams through without a break, Of which sort stuff of wood is seen to be.
