Hanky Panky

THE ILLUSION OF SUBTRACTION.

Against the wall of a room fix three small pieces of paper, about the size of a sixpence; let them be about half a foot asunder, and the height of the eye; stand about a yard distant, and, keeping both eyes steadfastly fixed on the centre piece, all three pieces are visible. Now shut the right eye (keeping the left still on the centre), and the piece which is opposite to the left eye disappears; or close the left eye, and the right piece cannot be seen: so that if either eye be shut, the paper opposite its fellow becomes invisible; plainly proving, that some objects opposite the left eye are viewed by the right, and vice versâ, with the left eye closed, and the right piece consequently invisible; remove the right eye from the centre, and carry it to the piece on the left; the right piece now becomes visible, but the centre disappears; and so on alternately, the three pieces not being visible at the same time, as when both eyes are open, showing one of the uses of having two eyes.

VARIATION.

Another method of trying this experiment is by holding both the thumbs together at a little distance from, and at the height of the eyes: shut the left eye, and keep the right steadfastly fixed on the left thumb-nail; move the right thumb gently away in a horizontal direction, and at the distance of two or three inches, the top of the thumb disappears; but by carrying it a little further, it becomes visible again.

COLOURED GLASSES IN FOGS.

When there is a fog between two places, so that the one station can with difficulty be seen from the other, if the observer passes a coloured glass between his eye and the eye-piece of his telescope, the effect of the fog is very sensibly diminished, so that frequently signals from the other station can be very plainly perceived, when, without the coloured glass, the station itself could not be seen. The different colours do not at all produce this effect in the same degree. The red seems the most proper for the experiment. Those who have good sight prefer the dark red: those who are short-sighted like light red better.

JAPANESE MYSTIC MIRRORS.

The bronze looking-glasses of Japan have the curious property of showing in their reflection of a strong light on a screen, not only their own polished surface, but the figures on the back.

These figures are fashioned by striking them out; they are then ground down till the raised metal is levelled to the deepest indentation, when the pattern is stamped once more, the face again ground, and the operation repeated.

The alteration in the metal where this compression has visited it, is not perceptible even with a magnifying glass, but in reflection it is shown.

TRANSFIGURATION PICTURES.

Having a picture on thin cardboard or paper, representing an interior or exterior of a building, cut out three sides of a door, so that it will bend back as if on hinges; behind the opening thus made fasten a second picture, depicting a landscape, or the inside of a room, as the case requires.

“Pity the Sorrows of a Poor Old Man.” The upper picture is that of a room with a fire in the chimney-place on one side, a well-filled supper table on the other, the door in the middle. The under picture has a background of a winter landscape, with an old blind man, leaning on his staff, and taking off his hat, so placed as to seem to be on the threshold.

“How glad they will be to see me!” The upper picture is a street, with a man about to open the door; the under picture a room, in which several children are quarrelling, amidst a chaos of broken toys, furniture, and looking-glass, with mamma upsetting the tea-table in trying to beat a bad boy teasing the cat.

THE EIDOTROPE.

Perforate two metal or board discs, and make one turnable around in front of the other, by means of a band and pulley, while both are mounted as a magic-lantern slide.

When their shadows are thrown on the screen, the effect of the revolving plate more or less eclipsing the other, is to create singular forms.

To imitate watered silk, use wire gauze. For effect, let the light pass through tinted glass.

A hand appears on the wall, and writes, and then rubs out what it has written. Light the gas in a dark room. Next procure a mirror, stand at the door of the room, and hold the mirror so that it will throw the light of the gas on the wall or a white sheet outside of the room. Now observe that, by holding your hand over the face of the mirror, the same hand appears on the white wall or sheet. Next procure a small paint-brush, about the size of a pen, and dip it in black paint, and then make any figure or character the reverse way on the mirror, and of course the same will appear on the wall on which the mirror reflects. Now lay the brush aside, and rub out the figures or characters off the mirror, and of course they will disappear off the wall also.

THE THEATRE WITH THE CURTAIN DOWN AND UP.

The sides of the proscenium and stage before the curtain unfold, and the curtain is a slip of paper which is pulled up to discover the tableau as above. The two figures are cut out and mounted on small spiral springs, which make them stand out upon the stage when released from pressure.

THE MAGIC INVERSION.

Join two square parallel ends by a third piece, half an inch broad and an inch and a half long, using a piece of cardboard doubled up, with that interval between, as the simplest material. In the middle of one end make a round hole, a little more than one-twelfth of an inch wide, and in the centre of it fix the head of a pin or point of a needle. Directly opposite, in the other side, make a large pinhole. If the latter is held to a strong light, and the eye is applied to the other hole, the head of the pin will be seen, not only greatly magnified, but turned upside down.

THE PRETENDED ENDLESS ARCADE.

In public gardens an apparently endless walk, under arches of gas-jets, is often seen. But, on walking down it, it is seen to be of restricted length, the illusion being obtained by an artful lessening of the sweep and height of the arch, after, during a certain distance, the arches have been regularly spaced out. This being done according to the rules of perspective, the keenest are deceived.

Draw a figure of a witch riding on a broomstick, or a capering demon, on a sheet of cardboard, and cut it clean out.

Make a square aperture in a partition facing a transparent screen, large enough to comprise the figure, say twelve inches, and place the cut-out board in it, tight as a pane of glass in its frame.

Let the part of the room where the audience sit be darkened, and the only light pass through the hole in the partition, or rather through the cut-out cardboard.

If but one light is held to the figure, the counterpart, enlarged according to the distance between the screen and the picture, will be single, but, on having three or more candles, the figures will be trebled or quadrupled, and the effect will be startling and whimsical.

The limbs of such figures can be fashioned of wire, and the result is highly amusing when a score of such figures are to be seen capering. The jaws can move as if masticating, the arms may brandish a club, a somersault may be executed, and so on. A ratchet and cogged wheel action will make the movement backward and forward regular and fully controllable.

The screen should be of cambric muslin, strained tightly, and soaked with a varnish composed of picked gum-arabic and white starch, which renders it diaphanous.

PENETRATIVE SIGHT.

Take a piece of pasteboard, about five inches square, roll it into a tube with one end just large enough to fit round the eye, and the other end rather smaller. Hold the tube between the thumb and finger of the right hand; put the large end close against the right eye, and with the left hand hold a book against the side of the tube. Be sure and keep both eyes open, and there will appear to be a hole through the book, and objects, seem as if through the hole instead of through the tube. The right eye sees through the tube, and the left eye sees the book, and the two appearances are so confounded together that they cannot be separated. The left hand can be held against the tube instead of a book, and the hole will seem to be as if through the hand.

THE BLIND SPOT IN THE EYE.

Look with both eyes on these two letters; then shut the right eye while you look at the R, and gradually bring the book near your face. There is a point where the L will disappear. Repeat with a change of the eye employed.

The dioptrical paradox consists of a hard-wood base, A, B, C, D, about eight inches square, with a groove in which slides coloured prints or drawings. Connected with the base are a pillar (E), a horizontal bar (F), with a tube (G) directly over the centre of the base, and containing a peculiarly shaped glass.

Performance.—An ace of diamonds, when placed on the base, will be actually shown as an ace of clubs to anybody looking down through the glass, or one animal is seen as another; in fact, any shape is presented as something different.

Explanation.—The glass (G) is like the common multiplying glass, except that its sides are flat and diverge from its hexagonal base upwards to a point in the axis of the glass, like a pyramid, each facet being an isosceles triangle.

Regulate its distance from the eye so that each side will refract the various parts of the drawing on the border so as to form one figure, and the centre object be entirely unreflected.

The ace of clubs is, therefore, drawn mechanically on the circle of refraction at six different parts of the border, and blended in with it. So with the other drawings.

THE MAGIC CUBE-BOX.

An illusion is often practised at fancy fairs and bazaars, when a spectator, looking into what he supposes to be an ordinary looking-glass, sees his companion instead of himself. Of course the exhibitor endeavours to show the illusion to two persons at once; and if they are strangers to each other, and of opposite sex, a great deal of fun is made out of the trick. Showmen at the fairs have made immense harvests by showing two such mirrors, one to all the young girls who wished to see their future husbands, and the other to all the young men who wished to see their future wives.

Explanation.—Make a cube-box, fifteen inches, say, each way, and stand it on a pedestal to bring it to the height of the eye. In each side of this box let there be an opening of an oval form, ten inches high and seven wide. In this box place two mirrors with their backs against each other. Let them cross the box in a diagonal line, and in a vertical position. Decorate the openings in the side of this box with four oval frames and transparent glasses, and cover each with a curtain so contrived that all draw up together.

Place four persons (in the case first mentioned two are confederates) in front of the four sides, and at equal distances from the box, and then draw them up that they may see themselves in the mirrors, when each of them, instead of his own figure, will see that of the person next to him, but who will appear to him to be placed on the opposite side. Their confusion will be the greater, as it will be very difficult, if not impossible, for them to discover the mirrors concealed in the box. The reason is that though the rays of light may be turned aside by a mirror, yet they always appear to proceed in right lines.

YELLOW AND BLUE DO NOT MAKE GREEN.

With an electric or lime-light throw a disc of blue light and of yellow light upon a screen, and cause them to overlap each other. Where they overlap the space on the screen will be, not green, but a pure white. If you then place a rod or pencil near the two sources of light, so that two shadows of it shall fall on the white space where the discs overlap, one shadow will be of brilliant blue colour, and the other deep yellow. Mixed blue and yellow lights, therefore, do not make green. Mixed blue and yellow paints make green, because between them they absorb nearly all the rays of the spectrum except green, so green is the only colour which escapes from the mixture.

A very curious practical illustration of this may be given. Everybody has a yellow spot, more or less marked, on the retina of the eye; and this yellow spot absorbs some of the greenish-yellow rays of the spectrum. If you throw on the screen a circle of light, coloured by passing the rays from the electric lamp through chloride of chromium, the disc will then consist chiefly of red rays mixed with the rays which are absorbed by the yellow spot. If the observers in the darkened theatre look at the disc and wink slowly, they will see, with more or less distinctness, an illusion like red clouds floating over the disc, in consequence of most of the rays other than the red being absorbed by the yellow spots in their eyes.

Trace on the hexagonal ground-plan, A, B, C, D, E, F, which serves as base to the building, the six semi-diameters, G A, G B, G C, G D, G E, G F, and on each of them rear perpendicularly two plain mirrors, joining all exactly at the centre, G. These glasses should be very thin, set back to back in each pair, and cut with a double bevel where the point of junction falls.

Ornament the six corners of the outer edge of the structure with as many columns and their bases, into which the outer edge of the mirrors fit by their grooves. Make the roof in any fashion you please.

In each of the six triangular spaces comprised between every two of the glass walls little pasteboard figures in relief, representing six different subjects, which will have a pleasing effect in a hexagonal form.

With some ornament harmonizing with the temple hide the junction of the mirrors.

Action.—When any one looks into one of the six openings between any two of the columns, the object there will be repeated six times, which will be an extraordinary illusion if the subjects are suitable to the arrangement of the mirrors.

Observation.—If a part of a fortification is mounted between two of the mirrors, such as a curtain and two demi-bastions, the entire citadel will be seen, surrounded by six bastions; apportion of a ball-room, with a quadrille party and one gaselier, will be multiplied, and so on.

The construction can be made on a triangular or square base, and is equally agreeable; but as only three or four subjects can be shown, and the parts of those subjects are parallel with the sides of the temple, and therefore take a form like that at its base, the result is not so wonderful.

Cut out a disc of cardboard or pasteboard, and drill three holes near the edge on two opposite sides, in each of which tie a length of string. In the centre on one side paint a jockey seated, and on the other centre, upside down as compared with the man, a running horse.

Performances.—If you take the strings, one set in each hand, and whirl the disc round as on a horizontal axle, the strings will twist and keep up the movement, during which the two pictures will unite as one. Other objects may be a bird and cage, a juggler doing the knife or ball tossing trick, a rat and trap, &c.

THE ARCADE OF VERDURE.

Make a box half as wide and high as long. At one end place a mirror, exactly the size of the board, and fixed firmly against it, and remove the quicksilver within a circle agreeing with an eyehole cut in the end. Back the opposite end in the same way with a plane mirror.

Prepare grooves at right angles across the box, in which will slide two sheets of cardboard, painted on both sides with trees and overarching foliage, with the lights cut clear out, taking care that a bough will prevent the eyehole being reflected in the opposite glass.

Paint two other boards similarly with foliage, and cut the lights out and set them against the mirrors.

Cover the box with gauze, and frame a sheet of ground glass to form the lid, which should be firmly fastened on. The bottom is to be painted sandy colour or green, or may be varnished and strewn with moss whilst wet. When viewed with a strong light, the effect will be as of an endless vista, gradually fading away in the distance.

(See “The Endless Vista,” p. 300, Magician’s Own Book.)

THE PERSPECTIVE GLASS.

At one end of a box, twenty inches long and twelve high and wide, place a concave mirror, of which the focus should be about fifteen inches from the reflecting surface. Blacken the other end inside, and cut an eyehole in it.

Darken the mirror by covering the top in from it to a little less than half way along the box, where a blackened frame should be set, with a sufficient opening to let the mirror reflect any object just under the eyehole at the other end, where a grooved cleat permits picture-slides to be inserted. Cover the other part of the box with ground glass or other transparent media, to keep the inside from being seen.

If you must use artificial light, let an aperture be practised in the mirror end, so that the source of the illumination cannot be perceived.

Simple as is this contrivance, the figure drawn on a plane surface will be given a natural perspective as wonderful as entertaining.

Take a life-size picture of a man in a full-bottomed wig, or a lady in a head-dress with head and shoulders only shown, and, having cut out the face and all the background, glue it to the back of a looking-glass, from which you have scraped away all the quicksilver just where this cut-out picture goes.

Undertake to show any one his forefather, or her ancestress, as the case may be, in their habiliments as they lived, and, on standing before the mirror, their face will be reflected in the vacant place.

Reverends Père Castel and the Abbé Poncell have constructed, on the supposed connection of flavours, perfumes, and colours, the following amusing scales:—

It is true that a blind man, noted in ocular science, likened the blast of a trumpet to scarlet, and Shakspeare speaks of the sweet south wind, but for the greater part of the above comparisons there is a deficiency of authorities.

Take a print of a human face, with a Rembrandt or Tintoretto effect of deep shadows and soft lights, and cut out the whole outline and all the lights, picking with a pin the thin lines and spots. Heads of Christ, and the Madonna as Our Lady of Sorrows, are excellent, for this purpose.

On holding these up between the white wall and a lighted candle, in a position found on trial, the figure formed seems to float vaguely instinct with mournful life, the indistinctness of the outline aiding the illusion.

IRREGULAR PROFILES FORMING SYMMETRICAL SHADOWS.

Nearly everybody has at some time been struck by the strangely accurate shapes made by the shadows cast by the edges of a pile of irregular formation, such as a heap of books, &c.

The heads of pipes, sword-hilts, umbrellas, and canes can be turned into shapes unrecognizable as at all human, yet giving a shadow, of which the outline reproduces the profile of some eminent man.

CHINESE SHADOWS.

Opaque bodies, cut in various shapes, are held against a transparent screen, with a powerful light behind them. The audience are in a dark room.

To increase the effect, make the figures of acrobats, rope-dancers, performers on the horizontal bar, &c., of sheet metal, and fit them with joints, so that the limbs can be moved by mounting them on thin rods at right angles with the rope on which they seem to walk. These rods can be turned by cranks, or end in a cogged wheel locking in a ratchet.

ANAMORPHOSES; OR, DISTORTED FIGURES.

Having drawn a subject, such as a human face, on a piece of paper, enclose it in a square, as A, B, C, D (Fig. 130), and divide it into smaller squares by marking off equal parts of the sides and drawing straight lines across, as when you wish to make a reduced copy of a picture.

Describe a parallelogram, E, B, F, G, the short side, E, G, being divided into as many equal parts as A B, in our example 7. From the centre of the side, B F, draw straight lines to the points of division on the side E G. Assume the point I, on the side B F, as the height of the eye above the picture; draw from I to the point E the straight line, which cuts the lines diverging from H at the points 1, 2, 3, 4, 5, 6, 7. Through these intersecting points draw parallel straight lines to divide the triangle into as many trapeziums as there are small squares in the square A, B, C, D.

Now fill up all the cells of the triangle with corresponding parts of the drawing, taking the base of the triangle to be the head of the picture transferred, and the comical distortion will be made. To see it, however, like its original, bore a hole, K, in a board, L, placed upright in H, so that the height, L K, equals H I, which must not be great, in order that the distortion may be remarkable.

Several lines of letters forming a phrase or sentence, can be distorted in a similar manner, so as to be read only by holding the paper so inscribed at a certain position as regards the eye. Further anamorphoses may be made by painting on curved surfaces, cylindrical, conical, or spherical, which appear natural when seen from a certain point of view. Still another way is to look at the reflection on a cylindrical mirror of a drawing made only so to appear regular.

Another way to obtain the distorted picture is to prick out the outlines of the original drawing, and hold it at an angle to a sheet of paper, so that the light on the other side, streaming through the pinholes, shall form a figure, which you can trace with pencil, more or less out of the true position. To see this changed picture corrected, you must place your eye where the light was.

By varying such pictures, they can be adapted to being seen aright by reflections in cylindrical, conical, pyramidal, and prismatic mirrors.

A Gerb of Fire.—On white paper draw the figure of a gerb of fire, lay it on quite opaque paper, black on both sides, and with a very sharp penknife cut several slashes at unequal intervals from the gerb centre; pierce these breaks with holes to represent the sparks. The lines and holes both paint the effect of burning powder issuing from a small aperture.

Globes, Pyramids, or Revolving Columns.—Draw the outlines on paper, and cut them out in a helical or spiral form. For the various tints, paste coloured transparent paper at the back.

TO GIVE MOTION.

Jet of Fire.—Prick various sized holes at unequal distances apart in a band of paper, but few in one part, others thinly scattered, others profusely sprinkled, to represent the sudden bursts of sparks. This band is to ascend between a light and the jet made on paper as above.

Cascade.—The same perforated band is to move downwards instead of upwards, which is done by making the band wind off one roller as another winds it on.

Globes, Columns, Pyramids.—The band of paper cut out in apertures inclined at a somewhat different angle from that of their spirals, must move upwards vertically. Thus the fire will seem to be continually ascending along these spirals, and the machine will appear to revolve with them.

Suns.—These are more difficult, as you must picture fire proceeding from the centre to the circumference. On strong paper describe a circle a little larger than the surface of your sun. On this trace two spirals, one-twelfth of an inch apart, and open the intervening space with a knife, cutting the paper from the circumference, decreasing in breadth to a certain distance from the centre. Then cut the remainder of the circle into similar spirals, alternately open and close. Paste it on an iron hoop, supported by an iron cross, and set all on a stand which will let it freely turn round its centre.

On placing this between a light and your sun, and moving it towards that side to which the convexity of the spiral is turned, the opening will give, on the image of the sun’s rays or jets of fire, the appearance of fire continuously flowing from the centre to the circumference.

THE SULTAN’S SUMMER PALACE ILLUMINATED.

Take a print of an Oriental palace, and colour it properly. On the back paste paper to make it but partially transparent. With differently sized points prick small holes in the places, and on the lines where lamps and lanterns are generally placed, as along the sides of windows, cornices, arches of doors, balustrades, and as if suspended from trees. The greater the supposed distance of these architectural and decorative features, the smaller and closer these punctures must be. With large punches cut out the stronger lights, as of Bengal fires in pots, and so forth.

Cut out the panes of some of the windows, and paste at the back gelatine paper of green or red colour, as if they were curtains within an illuminated room.

Place the print thus prepared in the front of a box representing a miniature theatre, strongly lighted from the back, and look at it through a convex glass of a rather long focus.

There may be added some pieces of Chinese or artificial fireworks, moved by clockwork.

THE PENETRATIVE EYEGLASS.

Perhaps some one in the company has made use of the saying that he “can see as far through a millstone as anybody.”

Eagerly espouse his cause, and declare him, indeed, gifted with preternatural vision, as you will prove to him by your magic spyglass.

A box is made with two upright extensions, in which are placed the tubes of telescopes, with plain glass eyepieces. A A A A are plane mirrors, set all at an angle of 45 degrees, so that any one looking in at either end, sees whatever is visible at the other extremity.

THE POLEMOSCOPE.

This is an utilisation of the last-mentioned trick.

If the higher glass is placed behind the other, or even with its sides parallel with its own, the latter could be behind an impenetrable wall to shelter the observer, without the landscape being out of the scope of vision.

Another plan is to place the upper mirror without a window above the house-door, to reflect the part of the street beneath upon a mirror within on the sill.

A third is in miniature, by which an opera-glass has an opening at the side of the barrel, by which one’s neighbours are scrutinized while, to all appearance, one is intently examining the performers. Happily the frequenters of the playhouse of the present day are less sensitive than our forefathers, and no such deceptions to avoid showing impoliteness are in request.

This is a modification of “The Sphinx,” or “The Head of the Decapitated Speaking,” as it is called, of which The Magician’s Own Book contains a full explanation.

A hole is made in a large plane mirror, through which the actor puts his head. It is set at an angle so as to reflect the ceiling of the little chamber where the decapitation has occurred; hence the spectators believe they see it suspended in the air. The front corners and edge of the mirror are artfully masked by architectural ornaments, and the upper edge enters at the joining point of the ceiling and supposed wall.

The description of the fiery-faced God of the Egyptians in Lord Lytton’s “Last Days of Pompeii” is vivid enough for it almost to provide data for an illusion in itself. However, we can form one upon it.

Get a false face made of the Egyptian type (the Sphynx would be suitable), of fine muslin, and dressed with wax to make it transparent. Fasten it on a board with drapery in accordance with it; cut out at the back a place where a white glass bottle can stand on a shelf, closed in on all sides by that in the opening, and containing a solution of a few grains of phosphorus in some essential oil of cloves. Have the stopper at the end of a rod working on a pivot, so that a touch will lift it out of the bottle. When out, the air entering makes the phosphorus glow with a mysterious light. The impression can be enhanced by a few chords on a celestine or harmonica.

Contrive a six-sided box, six inches in diameter and ten deep, lined with tin or other polished surface, and with a double convex lens in the centre of one side. On the opposite side, exactly in its middle, cut out a hole to receive the face of a watch, with a little shelf outside to hold the case firmly.

Support the box in the centre on a hollow leg, which is watertight and is filled with water, to float a night-light, and let the leg fit into a stand to go on a table by the bed-side or on a shelf at the foot of the bed.

Action.—The lens will magnify the reflection of the watchface so that the figures can be clearly distinguished.

DOUBLE-COLOURED REFLECTION.

Bore a hole through a disc of tinted glass with a bradawl, kept moist with oil of turpentine, frame it in your forefinger and thumb held around the edge, and let a strong light pass through it.

With a blue glass the centre spot will be orange; with green, red; with red, green, &c.

A plain white glass decanter is taken up and placed on a table, when it is filled with water. It is pretended that this fluid is enchanted, since, after a flower has been selected from a bouquet and burnt by the spectator himself, its exact image is presented in the bottle.

Explanation.—Behind a partition, A B (Fig. 140), place a concave mirror E F, ten inches diameter, and at a distance three-fourths from its centre, somewhat inclined. In the partition cut a square or circular opening, about eight inches wide, directly opposite the mirror. Behind have a light to illuminate any object at C, without shining on the mirror or being visible at the opening. Behind the aperture and beneath it place inverted the object of which a phantom is to appear.

Before the partition, just under the hole, set a bouquet-holder or flowerpot (or, at the opening, as in this case, the bottle of water), that the image may seem to be standing in it.

All extraneous light must be kept from the mirror by blackening the surfaces around it.

The spectator will see the image so real that he will be apt to attempt to pluck it, if a flower and a flowerpot is substituted for the bottle.

The different flowers of a bouquet have counterparts set on the circumference of a disc, of which the edge comes to the proper point to present one of them to the mirror.

The magician, on seeing a certain flower taken to be destroyed, has ample time to set the disc in motion and place the duplicate in position.

The Chadburn attachment to the oxyhydrogen microscope serves its purpose excellently, but a singular means of exhibiting opaque bodies, of any description whatever, has been contrived by the Optician Kruss, of Hamburg.

A tin box, 4 4 4 4, a foot cube, or a little less high than broad and long, is divided by a tin partition, M, into two compartments, A and B, dark chambers, in fact.

In the room, B, a lamp, C, has a concave reflector, D, which concentrates the light upon a condensing lens (commonly called a bull’s eye), E. This light is directed upon the place F, where a door is made with a convenient slit for the insertion of prints, cartes de visite, or other photographs, lace, gems, jewels (the most intricate patterns afford pictures of great beauty, and the scintillations of colour from diamonds and other stones are perfectly bewitching), &c. Or the door can be opened, and one’s hand, eye, ear, or any other object held to the light, is likewise projected on the screen through the tube H H. This tube is solidly inserted in the end of the room A, diametrically opposite an imaginary circle drawn on the side or end of the door F. A second tube slides freely in and out, containing two lenses, as in ordinary magic lanterns.

A screen is constructed of an upright frame, on which is smoothly stretched common white tissue-paper, or the same oiled, or linen or silk made transparent.

An object being placed in the door F, the light being turned on and the focus being properly obtained, the picture projected on the screen will be seen by persons on its other side greatly magnified.

Where the oxyhydrogen light cannot be used the lamp should furnish the next best light. Pure sperm oil, in which crushed camphor, an ounce to half a pint, has been dissolved in gentle heat, in a suitable lamp, with an argand chimney to prevent flickering, will be sufficient.

We should add that a tin chimney, bent as in magic lanterns, will, of course, be required to complete the apparatus.