# Familiar Colloquies/Concerning Certain Problems

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CONCERNING CERTAIN PROBLEMS.
Curio and Alphius.
'Cu. I should be glad to learn something of you who are well skilled in many things, if it would not be troublesome to you to inform me. Al. Well, Curio, go on then, propose what questions you have a mind to,' and be in fact what you are in name. Cu. I shall not take it amiss to be called Curio, so you do not put that monosyllable sus'(& sow) to it, that is hateful both to Venus and Minerva, and makes it Curiosus. Al. Speak out then. Cu. I have a mighty mind to know what we call heavy and light. Al. I may as well ask you what hot and cold is too : you should rather put that question to a porter than to me; or rather to an ass, who will tell you when the burden is heavy by hanging his ears. Cu. I expect a solution, not such a one as an ass can give, but such as becomes a philosopher, an Alpheus himself. Al. Heavy is that which naturally tends downwards, and light that which mounts upwards. Cu. How comes it about then that the antipodes, who are under us, do not fall into the sky that is under them ? Al. They may as well wonder why you do not fall into the heaven that is not under you but over you ; for the heaven is above all that are comprehended within it: nor are the antipodes under you any more than you above them. Nay, you might rather wonder why the rocks that the earth of the a'ntipodes sustains do not break and fall into heaven.
Cu. What then is the natural centre of heavy bodies ? and, on the other hand, of light bodies'? Al. All heavy things are by a natural motion carried towards the earth, and light things towards heaven : I do not speak of a violent or animal motion. Gu. Why, is there then a motion that is called an animal one ? Al. Yes, there is. 'Cu. What is it ? Al. It is that which is carried according to the four situations of the body forward, backward, to the right and left, and in a circle ; and in the beginning and end is swifter, and slowest in the middle ; for ​in the beginning vigour adds alacrity, and near the end the hope of coming to what the animal aims afc. Cu. I cannot tell how it is with other animals ; but I have got a maid-servant who is weary before she begins, and tired before she ends. But return to what you begun.
Al. I say, heavy things are carried downward by a natural motion; and by how much the heavier anything is, by so much a swifter motion it is carried towards the earth, and by how much the lighter it is, by so much the swifter motion it is carried toward heaven. It is quite otherwise in a violent motion, which, being swift at first, grows slower by degrees; and contrary in a natural motion, as an arrow shot into the air, and a stone falling from on high. Cu. I used to think that men ran about upon the globe of the earth like little ants on a great ball; they stick upon it everywhere, and none fall off. Al. That is to be attributed to the ruggedness of the globe, and a certain roughness in the feet of the ants, which, indeed, is common to all insects in a manner ; and lastly, to the lightness of their bodies. If you do not believe me, make a glass globe very smooth and sleek; you will see that only those ants do not fall that are at the upper part of it. Cu. If any god should bore through the centre of the earth, quite down to the antipodes, in a perpendicular line, and as cosmographers use to represent the situation of the globe of the earth, and a stone were let fall into it, whither would it go? Al. To the centre of the earth ; there all heavy bodies rest. Cu. What if the antipodes should let fall a stone on their side 1 Al. Then one stone would meet the other about the centre, and stop there.
Cu. But hark you, if what you said just now be true, that a natural motion by its progress grew more and more strong, if nothing hindered a stone or lead cast into the hole, by reason of the vehemence of its motion it would pass beyond the centre, and having got beyond the centre, the motion would grow more violent. Al. Lead would never come to the centre unless it were melted ; but a stone, if it did pass the centre with so violent a motion, would go at first more heavily and return to the centre again, just as a stone thrown up into the air returns again to the earth. Cu. But returning back again by its natural motion, and again recovering force, it would go beyond the centre, and so the stone would never rest. Al. It would lie still at last by running beyond, and then running back again till it came to an equilibrium. Cu. But if there be no vaciium in nature, then that hole must be full of air. Al. Suppose it to be so. 'Cu. Then a body that is by nature heavy will hang in the air. Al. "Why not ? as steel does, being borne up by the loadstone. What wonder is it that one stone hang in the very middle of the air, when the whole earth laden with so many rocks hangs after the same manner ?
Cu. But where is the centre of the earth? AL Where is the centre of a circle ? Cu. That is a point that is indivisible ; if the centre of the earth be so small, whosoever bores through the centre takes it away, and then heavy bodies have nowhere to tend to. Al. Xow you talk idly enough. Cu. Pray, do not be angry ; what I say is for the sake of information. If any one should bore through the globe of the earth, and not through the centre itself, as suppose one hundred furlongs aside of it, where would a stone fall then? Al. It would not pass straight through the hole. It would, indeed, go ​straight, but to the centre ; and so when it came to the middle it would rest in the earth on the left hand, if the centre were at the left hand.
Cu. But what is H that makes a body heavy or light ? Al. That is a question fit for God to answer, why He made fire the lightest of all things, and air next to that ; the earth the heaviest, and water next to that. Cu. Why, then, do watery clouds hang in a lofty air? Al. Because by the attraction of the sun they conceive a fiery nature, as smoke being forced by a violent motion out of green wood. Cu. Why, then, do they sometimes fall with such a weight that they level moun- tains into, a plain ? Al. Concretion and density add a weight to them, and they may be imagined so to be borne up by the air under them, as a thin plate of iron is borne up upon the surface of the water. Cu, Do you think, then, that whatsoever has most of a fiery quality in it is lightest, and that which has most of an earthy quality heaviest 1 Al. You are right. Cu. But air is not all of a lightness, nor earth all of a heaviness, and it is the same as to water. Al. Nor is that strange, since those things you have mentioned are not pure elements, but tempered of various elements ; so that it is probable that earth is the lightest that has the most fire or air mixed with it, and that water heaviest that has earth, which is heaviest, mixed with it, as, I think, sea-water is, and that whereof salt is made. And, in like manner, that air that is nearest to water or earth is the heaviest, or, at least, it is certainly not so light as that which is farther from the earth.
Cu. Which has most of an earthy quality in it, a stone or lead 1 Al. A. stone: Cu. And yet lead is heavier than a stone in proportion. A I. (The density is the cause.) That proceeds from its solidity ; for a stone is more porous, and so contains more air in it than lead does. Hence it is that we see some sort of dry earth, which if you cast into water will swim and not sink; so we see whole fields floating, being borne up by hollow roots of reeds and other marshy herbs, interwoven one with another. Gu. Perhaps it is from this cause that a pumice- stone is so light. Al. Because it is full of pores, and very much burnt in the fire ; they are thrown out of burning places. Cu. Whence is it that cork is so light. Al. That has been answered already ; the spongy hollowness of it is the cause.
Cu. Which is heaviest, lead or gold 1 Al. Gold, in my opinion.
Cu. But yet gold seems to have more of a fiery nature than lead. Al. What, because, as Pindar says, it shines by night like fire 1 Cu. Yes. Al. But gold has the greater solidity. Cu. How is that found 1 Al. Goldsmiths will tell you that neither silver, lead, nor copper, nor any such kind of metal, can be hammered out so thin as gold can. And, for the same reason, philosophers gather that there is nothing more liquid than honey and oil ; that if any one spread this, or daub anything with it, it will spread the widest and be longest in drying of anything. Cu. But which is heaviest, oil or water 1 ? Al. If you speak of linseed-oil, I take oil to be the heaviest. Cu. Why, then, does oil swim upon water ? Al. The lightness is not the cause, but the fiery nature of oil, and a peculiar natiire in all fat things that is contrary to water; as it is in the herb that is called "A/3a7TTpc- Cu. Why, then, does not iron swim when it is red hot 1 Al. Because the heat is not a natural one, and therefore the sooner penetrates the ​water, because the intenseness of the heat dispels the resisting water ; so an iron wedge sinks sooner to the bottom than a thin plate. Cu. Which is the most unbearable, hot iron or cold 1 ? Al. Hot. Cu. Then it is heavier. Al. It is, if it be better to carry burning straw in your hand than a cold flint. Cu. What is the cause that one wood is heavier or lighter than another ? Al. The solidity or hollownes.s. Cu. But I knew one of the King of England's household who, when we were at table, shewed us some wood which, he said, was the wood of an aloes tree, so solid that it seemed to be a stone, and so light, if you poised it in your hand, that it seemed a reed ; being put into wine (for he was of opinion that so it would expel poison), it presently sunk to the bottom as swiftly as lead would.
Al. Neither solidity nor hollowness is always the cause, but a peculiar occult agreement between things, which is the cause that some things embrace or shun other things of a cognate or different quality, as a loadstone attracts steel, and a vine avoids a colewort ; and flame will reach toward naphtha set in a lower place, although it be at some distance, and yet naphtha is naturally heavy and flame light. Cu. All sorts of money swim in quicksilver, and gold only sinks and is inclosed in it, yet quicksilver is very liquid. Al. I can give no sohition to that, but a peculiar cognate quality ; and quicksilver was made for the refinement of gold. Cu. Why does the River Arethusa run under the Sicanian Sea, and not rather swim upon it, when you say that sea- water is heavier than river-water? Al. A natural disagreement is the cause, but it is a secret one. Cu. Why do swans swim, when men going into the same water sink? Al. The cause is not only the hollowness and lightness of their feathers, but also a dry ness that the water shuns. And hence it comes to pass that if you put water or wine into a cloth or linen that is very dry, it contracts itself into a globular form; but pit it into a wet one, it spreads itself presently. And, in like manner, if you pour any liquid thing into a dry cup, or whose brims are greased with fat, and pour a little more than the cup will hold, the liquor presently gathers itself into a round before it will run over the brim.
Cu. Why cannot ships carry so much in rivers as in the sea ? A I. Because river-water is of a thinner consistence ; and for the same reason birds poise themselves with more ease in a thick air than in a thin one. Cu. Why does not the fish called flota sink? Al. Because its skin being dried in the sun is made lighter, and resists moisture. Cu. Why does iron drawn out into a large plate swim, but being con- tracted in a narrow compass sink ? Al. It is dryness is the cause in part, and partly because there gets in an air between the plate and the water. Cu. Which is the heaviest, wine or water ? AL I believe wine will not give place to water. Cu. How comes it about, then, that they that buy wine of the vintners sometimes find water in the bottom of the cask ? Al. Because there is in wine a certain fat substance like oil that resists the water; the reason is plain, by how much richer the wine is, so much the more difficiiltly does it mingle with water; and being set on fire, it burns the fiercer. Cu. What is the reason that no living creature will sink in the Lake Asphaltus ? Al. I cannot give a solution to all the miracles in nature ; nature has some arcana that she will have us admire but not understand. ​Cu. Why is a lean roan heavier than a fat man, supposing them both of an equal size? AL Because bones are more solid than flesh, and therefore the more weighty. Cu. Why is the same man heavier when he is fasting than after lie has ate his dinner, and so added a weight to his body. AL Because by meat and drink the spiiits are increased, and they add a lightness to the body ; and hence it is that a merry man is heavier than a sorrowful one, and a dead man than a living one. Cu. But how is it that the same man can make himself heavier or lighter when he pleases? Al. By holding, in his breath he makes himself lighter, and by breathing it out heavier ; so a bladder when blown, and close tied, swims ; but when it is burst, sinks. But when will Curio have done asking questions ?
"Cu. I will leave off if you will tell me but a few things more ? Is the heaven heavy or light? Al. I cannot tell whether it be light or no, but I am sure it cannot be heavy, it being of the nature of fire. Cu. What then does the old proverb mean, What if the sky should fall? Al. Because the ignorant ancients, following Homer, believed the heaven to be made of iron ; but Homer called it iron from the similitude of colour, not of weight, as we call that ashy that is of the colour of ashes. Cu. Is there any colour in the sky? Al. There is not really any colour in it; but it appears so to us, because of the air and water that is betwixt us and it ; as the sun sometimes appears to us to be red, sometimes yellow, sometimes white, when of itself it admits of no such mutations. In like manner the colours of the rain- bow are not in the sky but in the moist air.
Cu. But to make an end ; you confess there is nothing higher than the heaven, which way soever it covers the orb of the earth* Al. I do confess so. Cu. And nothing deeper than the centre of the earth. A L No. Cu. Of all things in the world what is the heaviest? Al. Gold, in my opinion. [Cu. I differ very much from you in this point. Al. Why, do you know of anything that is heavier than gold ? Cu. Yes, I do, and by many degrees too. Al. Then now do you take your turn and teach me ; for I profess I do not know anything that is. Cu. Must not that needs be the heaviest thing in the world that forced down the fiery spirits from the very vortex of heaven to the bottom of hell ? and that (you know) is placed in the centre of the earth. Al. I confess it ; but what is that? Cu. Sin, which plunges the souls of men> that Virgil calls sparks of pure ether, to the same place. Al. If you have a mind to pass to that sort of philosophy, I confess both gold and lead to be as light as feathers compared to it. Cu. How then can they that are laden with this sort of luggage mount up to heaven? Al. In truth I cannot tell. Cu. They that prepare themselves for running or leaping do not only lay aside all heavy things, but make themselves light by holding in their breath; when as to the race and leap that we take to heaven we do not endeavour to throw aside that which is heavier than stone or lead. Al. Ay, but we should do it if we had but one grain of sound judgment.