Part 9

Moisture is always present in the air, even when it is driest. To prove this, press a piece of sheet copper into the form of a cup; place on it a piece of phosphorus, thoroughly dried between blotting-paper; put the cup on a dry plate, and beside it a small piece of quick-lime; turn over it a glass tumbler, and leave it for ten minutes, that the lime may remove all moisture from the included air; take off the tumbler, touch the phosphorus with a hot wire, and instantly replace the glass; when a dry solid will be formed, resembling snow. As soon as the flame is extinct, examine the plate; when the solid will, in a very short time, attract so much water from the air, that it will pass into small drops of liquid.

CLIMATES OF A ROOM.

The air in a room may be said to resemble two climates: as it is lighter than the external air, a current of colder or heavier air is continually pouring in from the crevices of the windows and doors; and the light air must find some vent, to make way for the heavy air. If the door be set a-jar, and a candle held near the upper part of it, the flame will be blown outwards, showing that there is a current of air flowing out from the upper part of the room; and, if the candle be placed on the floor, close by the door, the flame will bend inwards, showing that there is also a current of air setting into the lower part of the room. The upper current is the warm, light air, which is driven out to make way for the stream of cold, dense air, which enters below.

BUBBLES ON CHAMPAGNE.

Pour out a glass of champagne, or bottled ale, and wait till the effervescence has ceased; you may then renew it by throwing into the liquor a bit of paper, a crumb of bread, or even by violently shaking the glass. The bubbles of carbonic acid chiefly rise from where the liquor is in contact with the glass, and is in greatest abundance at those parts where there are asperities. The bubbles setting out from the surface of the glass are at first very small; but they enlarge in passing through the liquor. It seems as if they proceeded more abundantly from the bottom of the glass than from its sides; but this is an ocular deception.

PROOFS THAT AIR IS A HEAVY FLUID.

Expel the air out of a pair of bellows, then close the nozzle and valve-hole beneath, and considerable force will be requisite to separate the boards from each other. This is caused by the pressure or weight of the atmosphere, which, acting equally upon the upper and lower boards externally, without any air inside, operates like a dead weight in keeping the boards together. In like manner, if you stop the end of a syringe, after its piston-rod has been pressed down to the bottom, and then attempt to draw it up again, considerable force will be requisite to raise it, depending upon the size of the syringe, being about fourteen or fifteen pounds to every square inch of the piston-rod. When the rod is drawn up, unless it be held, it will fall to the bottom, from the weight of the air pressing it in.

Or, fill a glass tumbler to the brim with water, cover it with a piece of thin wet leather, invert it on a table, and try to pull it straight up, when it will be found to require considerable force. In this manner do snails, periwinkles, limpets, and other shells adhere to rocks, &c. Flies are enabled to walk on the ceiling of a room, up a looking-glass, or window-pane, by the air pressing on the outside of their peculiarly-constructed feet, and thus supporting them.

To the same cause must be attributed the firmness with which the oyster closes itself; for, if you grind off a part of the shell, so as to make a hole in it, though without at all injuring the fish, it may be opened with great ease.

TO SUPPORT A PEA ON AIR.

This experiment may be dexterously performed by placing a pea upon a quill, or the stem of a tobacco-pipe, and blowing upwards through it.

PYROPHORUS, OR AIR-TINDER.

Mix three parts of alum with one of wheat flour, and put them into a common phial; set it in a crucible, up to the neck in sand; then surround the crucible with red-hot coals, when first a black smoke, and next a blue sulphureous flame, will issue from the mouth of the phial; when this flame disappears, remove the crucible from the fire, and when cold, stop the phial with a good cork. If a portion of this powder be exposed to the air, it will take fire.

Or, a very perfect and beautiful pyrophorus may be obtained by heating tartrate of lead in a glass tube, over a lamp. When some of the dark brown mass thus formed is shaken out in the air, it will immediately inflame, and brilliant globules of lead cover the ignited surface.

Or, mix three parts of lamp-black, four of burnt alum, in powder, and eight of pearl-ash, and heat them for an hour, to a bright cherry red, in an iron tube. When well made, and poured out upon a glass plate or tile, this pyrophorus will kindle, with a series of small explosions, somewhat like those produced by throwing potassium upon water; but this effect should be witnessed from a distance.

Put a small piece of grey cast-iron into strong nitric acid, when a porous, spongy substance will be left untouched, and will be of a dark grey colour, resembling plumbago. If some of this be put upon blotting paper, in the course of a minute it will spontaneously heat and smoke; and, if a considerable quantity be heaped together, it will ignite and scorch the paper; nor will the properties of this pyrophorus be destroyed by its being left for days and weeks in water.

BEAUTY OF A SOAP BUBBLE.

Blow a soap bubble, cover it with a clean glass to protect it from the air, and you may observe, after it has grown thin by standing a little, several rings of different colours within each other round the top of it. The colour in the centre of the rings will vary with the thickness; but, as the bubble grows thinner, the rings will spread, the central spot will become white, then bluish, and then black; after which the bubble will burst, from its extreme tenuity at the black spot, where the thickness has been proved not to exceed the 2,500,000th part of an inch.

WHY A GUINEA FALLS MORE QUICKLY THAN A FEATHER THROUGH THE AIR.

The resistance of the air to fallen bodies is not proportioned to the weight, but depends on the surface which the body opposes to the air. Now, the feather exposes, in proportion to its weight, a much greater surface to the air than a piece of gold does, and therefore suffers a much greater resistance to its descent. Were the guinea beaten to the thinness of gold-leaf, it would be as long, or even longer in falling than the feather; but, let both fall in a vacuum, or under the receiver of an air-pump, from which the air has been pumped out, and they will both reach the bottom at the same time; for gravity, acting independently of other forces, causes all bodies to descend with the same velocity.

An apparatus for performing this experiment is shown in the engraving: the coin and the feather are to be laid together, on the brass flap, A or B: this may be let down by turning the wire, C, which passes through a collar of leather, D, placed in the head of the receiver.

SOLIDITY OF AIR.

Provide a glass tube, open at each end; close the upper end by the finger, and immerse the lower one in a glass of water, when it will be seen that the air is material, and occupies its own space in the tube, for it will not permit the water to enter it until the finger is removed, when the air will escape, and the water rise to the same level in the inside as on the outside of the tube.

BREATHING AND SMELLING.

Hold the breath, and place the open neck of a phial, containing oil of peppermint, or any other essential oil, in the mouth, and the smell will not be perceived; but, after expiration, it will be easily recognised.

SLEIGHTS AND SUBTLETIES.

THE chief requisites for success in the performance of feats of Magic are manual dexterity and self-possession. The former can only be acquired by practice; the latter will be the natural result of a well-grounded confidence. We subjoin a few preliminary hints, of considerable importance to the amateur exhibiter.

1. Never acquaint the company before-hand with the particulars of the feat you are about to perform, as it will give them time to discover your mode of operation.

2. Endeavour, as much as possible, to acquire various methods of performing the same feat, in order that if you should be likely to fail in one, or have reason to believe that your operations are suspected, you may be prepared with another.

3. Never venture on a feat requiring manual dexterity, till you have previously practised it so often as to acquire the necessary expertness.

4. As diverting the attention of the company from too closely inspecting your manœuvres is a most important object, you should manage to talk to them during the whole course of your proceedings. It is the plan of vulgar operators to gabble unintelligible jargon, and attribute their feats to some extraordinary and mysterious influence. There are few persons at the present day credulous enough to believe such trash, even among the rustic and most ignorant; but as the youth of maturer years might inadvertently be tempted to pursue this method, while exhibiting his skill before his younger companions, it may not be deemed superfluous to offer a caution against such a procedure. He may state, and truly, that every thing he exhibits can be accounted for on rational principles, and is only in obedience to the unerring laws of Nature; and although we have just cautioned him against enabling the company themselves to detect his operations, there can be no objection (particularly when the party comprises many younger than himself) to occasionally show by what simple means the most apparently marvellous feats are accomplished.

THE RING AND THE HANDKERCHIEF.

This may be justly considered one of the most surprising sleights; and yet it is so easy of performance, that any one may accomplish it after a few minutes’ practice.

You previously provide yourself with a piece of brass wire, pointed at both ends, and bent round so as to form a ring, about the size of a wedding-ring. This you conceal in your hand. You then commence your performance by borrowing a silk pocket handkerchief from a gentleman, and a wedding-ring from a lady; and you request one person to hold two of the corners of the handkerchief, and another to hold the other two, and to keep them at full stretch. You next exhibit the wedding-ring to the company, and announce that you will make it appear to pass through the handkerchief. You then place your hand under the handkerchief, and substituting the false ring, which you had previously concealed, press it against the centre of the handkerchief, and desire a third person to take hold of the ring through the handkerchief, and to close his finger and thumb through the hollow of the ring. The handkerchief is held in this manner for the purpose of showing that the ring has not been placed within a fold. You now desire the persons holding the corners of the handkerchief to let them drop; the person holding the ring (through the handkerchief as already described) still retaining his hold.

Let another person now grasp the handkerchief as tight as he pleases, three or four inches below the ring, and tell the person holding the ring to let it go, when it will appear to the company that the ring is secure within the centre of the handkerchief. You then tell the person who grasps the handkerchief to hold a hat over it, and passing your hand underneath, you open the false ring, by bending one of its points a little aside, and bringing one point gently through the handkerchief, you easily draw out the remainder; being careful to rub the hole you have made in the handkerchief with your finger and thumb, to conceal the fracture.

You then put the wedding-ring you borrowed over the outside of the middle of the handkerchief, and desiring the person who holds the hat, to take it away, you exhibit the ring (placed as described) to the company.

THE KNOTTED HANDKERCHIEF.

This feat consists in tying a number of hard knots in a pocket handkerchief borrowed from one of the company, then letting any person hold the knots, and by the operator merely shaking the handkerchief, all the knots become unloosed, and the handkerchief is restored to its original state.

To perform this excellent trick, get as soft a handkerchief as possible, and taking the opposite ends, one in each hand, throw the right hand over the left, and draw it through, as if you were going to tie a knot in the usual way. Again throw the right-hand end over the left, and give the left-hand end to some person to pull, you at the same time pulling the right-hand end with your right hand, while your left hand holds the handkerchief just behind the knot. Press the thumb of your left hand against the knot to prevent its slipping, always taking care to let the person to whom you gave one end pull first, so that, in fact, he is only pulling against your _left hand_.

You now tie another knot exactly in the same way as the first, taking care always to throw the right-hand end over the left. As you go on tying the knots, you will find the right-hand end of the handkerchief decreasing considerably in length, while the left-hand one remains nearly as long as at first; because, in fact, you are merely tying the right-hand end _round the left_. To prevent this from being noticed, you should stoop down a little after each knot, and pretend to pull the knots tighter; while, at the same time, you press the thumb of the right hand against the knot, and with the fingers and palm of the same hand, draw the handkerchief, so as to make the left-hand end shorter, keeping it at each knot as nearly the length of the right-hand end as possible.

When you have tied as many knots as the handkerchief will admit of, hand them round for the company to feel that they are firm knots; then hold the handkerchief in your right hand, just below the knots, and with the left hand turn the loose part of the centre of the handkerchief over them, desiring some person to hold them. Before they take the handkerchief in hand, you draw out the right-hand end of the handkerchief, which you have in the right hand, and which you may easily do, and the knots being still held together by the loose part of the handkerchief, the person who holds the handkerchief will declare he feels them: you then take hold of one of the ends of the handkerchief which hangs down, and desire him to repeat after you, one—two—three,—then tell him to let go, when, by giving the handkerchief a smart shake, the whole of the knots will become unloosed.

Should you, by accident, whilst tying the knots, give the wrong end to be pulled, a hard knot will be the consequence, and you will know when this has happened the instant you try to draw the left-hand end of the handkerchief shorter. You must, therefore, turn this mistake to the best advantage, by asking any one of the company to see how long it will take him to untie one knot, you counting the seconds. When he has untied the knot, your other knots will remain right as they were before. Having finished tying the knots, let the same person hold them, and tell him that as he took two minutes to untie one knot, he ought to allow you fourteen minutes to untie the seven; but as you do not wish to take any advantage, you will be satisfied with fourteen seconds.

You may excite some laughter during the performance of this trick, by going to the owner of the handkerchief, and desiring him to assist you in pulling a knot, saying, that if the handkerchief is to be torn, it is only right that he should have a share of it; you may likewise say that he does not pull very hard, which will cause a laugh against him.

THE INVISIBLE SPRINGS.

Take two pieces of white cotton _cord_, precisely alike in length; double each of them separately, so that their ends meet; then tie them together very neatly, with a bit of fine cotton _thread_, at the part where they double (_i. e._ the middle). This must all be done beforehand.

When you are about to exhibit the sleight, hand round two other pieces of cord, exactly similar in length and appearance to those which you have prepared, but not tied, and desire your company to examine them. You then return to your table, placing these cords at the edge, so that they fall (apparently accidentally) to the ground behind the table; stoop to pick them up, but take up the prepared ones instead, which you have previously placed there, and lay _them_ on the table.

Having proceeded thus far, you take round for examination three ivory rings; those given to children when teething, and which may be bought at any of the toyshops, are the best for your purpose. When the rings have undergone a sufficient scrutiny, pass the prepared double cords through them, and give the two ends of one cord to one person to hold, and the two ends of the other to another. Do not let them pull hard, or the thread will break, and your trick be discovered. Request the two persons to approach each other, and desire each to give you one end of the cord which he holds, leaving to him the choice. You then say, that, to make all fast, you will tie these two ends together, which you do, bringing the knot down so as to touch the rings; and returning to each person the end of the cord next to him, you state that this trick is performed by the rule of contrary, and that when you desire them to pull hard, they are to slacken, and _vice versâ_, which is likely to create much laughter, as they are certain of making many mistakes at first.

During this time, you are holding the rings on the fore-finger of each hand, and with the other fingers preventing your assistants from separating the cords prematurely, during their mistakes; you at length desire them, in a loud voice, to slacken, when they will pull hard, which will break the thread, the rings remaining in your hands, whilst the strings will remain unbroken: let them be again examined, and desire them to look for the springs in the rings.

THE MIRACULOUS APPLE.

To divide an apple into several parts, without breaking the rind:—Pass a needle and thread under the rind of the apple, which is easily done by putting the needle in again at the same hole it came out of; and so passing on till you have gone round the apple. Then take both ends of the thread in your hands and draw it out; by which means the apple will be divided into two parts. In the same manner, you may divide it into as many parts as you please, and yet the rind will remain entire. Present the apple to any one to peel, and it will immediately fall to pieces.

THE SELF-BALANCED PAIL.

You lay a stick across the table, letting one-third of it project over the edge; and you undertake to hang a pail of water on it, without either fastening the stick on the table, or letting the pail rest on any support; and this feat, the laws of gravitation will enable you literally to accomplish.

You take the pail of water, and hang it by the handle upon the projecting end of the stick, in such a manner that the handle may rest on it in an inclined position, with the middle of the pail within the edge of the table. That it may be fixed in this situation, place another stick with one of its ends resting against the side at the bottom of the pail, and its other end against the first stick, where there should be a notch to retain it. By these means, the pail will remain fixed in that situation, without being able to incline to either side; nor can the stick slide along the table, or move along its edge, without raising the centre of gravity of the pail, and the water it contains.

THE PHANTOM AT COMMAND.

This feat is performed by means of confederacy.—Having privately apprised your confederate that when he hears you strike one blow, it signifies the letter A; when you strike two, it means B; and so on for the rest of the alphabet, you state to the company, that if any one will walk into the adjoining room, and have the door locked upon him, perhaps the animal may appear to him which another person may name.

In order to deter every one except your confederate from accepting the offer, you announce at the same time, that the person who volunteers to be shut up in the room must be possessed of considerable courage, or he had better not undertake it. Having thus gained your end, you give your confederate a lamp, which burns with a very dismal light; telling him, in the hearing of the company, to place it on the middle of the floor, and not to feel alarmed at what he may happen to see. You then usher him into the room, and lock the door.

You next take a piece of black paper, and a bit of chalk, and giving them to one of the party, you tell him to write the name of any animal he wishes to appear to the person shut up in the room. This being done, you receive back the paper, and after showing it round to the company, you fold it up, burn it in the candle, or lamp, and throw the ashes into a mortar; casting in at the same time a powder, which you state to be possessed of valuable properties.

Having taken care to read what was written, you proceed to pound the ashes in the mortar thus: Suppose the word written to be CAT, you begin by stirring the pestle round the mortar several times, and then strike three distinct blows, loud enough for the confederate to hear, and by which he knows that the first letter of the word is C. You next make some irregular evolutions of the pestle round the mortar, that it may not appear to the company that you give nothing but blows, and you then strike one blow to denote A. Work the pestle about again, and then strike twenty blows, which he will know to mean T; finishing your manœuvre by working the pestle about the mortar, the object being to make the blows as little remarkable as possible. You then call aloud to your confederate, and ask him what he sees. At first he is to make no reply. At length, after being interrogated several times, he asks if it be a CAT.

That no mistake may be made, each party should repeat to himself the letters of the alphabet in the order of the blows.

THE MIRACULOUS SHILLING.

Provide a round box, the size of a large snuff-box, and likewise eight other boxes, which will go easily into each other, letting the least of them be of the size to hold a shilling. Observe that all these boxes must shut so freely that they may all be closed at once, by the covers accurately fitting within each other.

Previously to commencing your performance, fit the boxes within each other, and place them in a table drawer at another part of the room. You also fit the covers in the same manner, and lay them by the side of the boxes; you likewise provide a silk handkerchief, into one corner of which a shilling is sewed.

You now commence your operations, by borrowing a shilling, desiring the lender to mark it, that it may not be changed. Take this shilling in your right hand, and the handkerchief in your left, pretending to place the shilling in the centre of the handkerchief; instead of which, you put the corner of the handkerchief in which a shilling was sewed, as previously described, concealing the borrowed shilling in your right hand. You then desire the person to feel that the shilling is there, and tell him to hold it tight.

You now go to the drawer, and placing the borrowed shilling in the smallest of the boxes, you put on all the covers, by taking them in the centre between the fore-finger and thumb, to prevent their separation, and fit them on, by carefully sliding them along, and then pressing them down.