So 9^ OF THE U N IVER.S ITY OF I LLI N 0 I 5 793. a B83f The person charging this material is re¬ sponsible for its return to the library from which it was withdrawn on or before the Latest Date stamped below. Theft, mutilation, and underlining of books are reasons for disciplinary action and may result in dismissal from the University. UNIVERSITY OF ILLINOIS LIBRARY AT URBANA-CHAMPAIGN APR 12 APR 2 8 1 I'll f ft * * J1IN24 APR 1 TO %0fTl 1978 9 r 377 *1 385 DEC MAR $ 3 1998 MAR :s 1 1393 ? m v APP 1 f 1977 APR 13 APR 1 5 DEC 16 FEB 2 2 198B Mil? 3 1980 1988 1982 L161 —0-1096 FUN WITH MAGIC Amusing Experiments in Physics, Chemistry and Geometry BY GEORGE BRUNEL WITH OVER ONE HUNDRED ILLUSTRATIONS CHICAGO JAMIESON - HIGGINS CO. 1901 COPYRIGHT, I9OI, BY JAMIESON-HIGG1NS CO, PREFATORY NOTE. T HE sole aim of this little book, aside from its purposes as a source of profitable pastime, is to show that a number of scientific phenomena can be verified in the home without the use of costly apparatus. The experiments presented are all simple, and may be readily performed with the use of common objects. While some are a little more complicated than others, they are nevertheless practical, and in the event of their proving too difficult, may easily be dispensed with from among so large a number. 1 M A k x 800542 CONTENTS. PAGB PAGE The Pile of Checkers . 5 An Hydraulic Screw . 55 The Obedient Coin 7 A Screw in the Air 57 The Insensible Coin 9 A Screw by Hot Air . 58 A Clever Stroke .... 11 A Little Cannon .... 59 A Counter-Stroke 12 Weighing Gas. 61 Balancing a Knife in Space . 13 The Magic Wheel 63 A Coin Balanced .... *4 The Rings of Smoke . 64 The Inclined Plane *5 The Microphonic Stick . 66 The Walking Cork . 17 The Three Colors .... 68 The Mysterious Apple 18 A Picture of a Volcano . 69 An Amateur Pneumatic Machine 20 Complementary Colors 70 A Balloon in a Vacuum . 26 The Recomposition of Light . 7* Suffocation in a Vacuum . 27 The Phantom Pin 74 Ebullition in a Vacuum . 28 Amphitrite. 75 A Voiceless Bell .... 2 9 Illusions in Optics .... 78 The Ventilator .... 30 A Simple Experiment with Static The Bursted Bladder . 3 1 Electricity. 81 Resisting the Pressure of the Air 33 Magnetic Attraction . 83 Compressed Air .... 35 The Magnetic Specter 84 The Effect of Condensation . 36 Animal Magnetism 85 Pulverization with Petroleum 37 Principle of a Galvanic Battery 87 A Barometer. 38 A Battery with a Lemon . 88 A Suction Pipe .... 4* Electric Attraction and Repul- Ascent of Water in a Vacuous sion . 90 Decanter. 42 Metallic Colors .... 9 2 The Submerged Coin . 44 The Weight of Steam Contained The Perverse Cork 45 in the Air. 95 The Pressure of Gas . 47 Metallic Arborizations . 97 An Egg as a Steam Engine . 5° Instantaneous Crystallizations . 97 The Imaginative Swivel . 5 2 Volcanoes in Miniature 98 An Experiment with Locomo- A Rudimentary Gas Burner . 99 tion. 54 Camphor in Water . . . 1 too CONTENTS — Continued, PAGE How to Make Ice . . . ioi How to Cut a Bottle with a Piece of Twine . . . ioi The Bridge of Asses . . .103 Another Way of Demonstrating the Same Theorem . . 105 Re-Entering Angles . . .107 Tracing Parallel Hatchings . 109 How to Draw a Spiral . .111 The Perspectograph . . .113 Ascertaining the Height of an Edifice or a Mountain .118 A Practical Way of Finding a Meridian.119 A Filter.122 An Accurate Pair of Scales , 124 An Economical Letter-Weight 127 A Photographic Camera . .128 An Economical Plate Holder . 131 The Taclc in the Ceiling . .132 To Cut a Rope with the Hands.134 A Drawing Glass . . . 135 An Archery with Pens . .137 PAGE A Simple and Economical Mul- tipligraph. 138 The Magic Theatre . 00 CO M The Hermetical Cork . 140 An Economical Binding for Papers. 141 Rapid Vegetation .... 143 The Automatic Pedestrienne . 144 The Horsewoman .... 146 The Mechanical Elephant 149 The Somersault .... 152 The Boxers. r S 5 The Top Spouting Water . *57 A Trick After Robert Houdin *59 Popular Fire-Works . 1 61 A Target Line . 162 The Enchanted Coin . 163 A Diminutive Catapult i6 5 The Four Matches 166 How to Raise Four Knives with One Knife . 168 The Vaulting Pea . . . . 169 A Problem in Checkers . 171 Shadow-Pictures . 172 FUN WITH MAGIC THE PILE OF CHECKERS. We read in all books on physics that matter is inert. Here is a very simple experiment which will serve to demonstrate the accuracy of this statement. Take a pile of about one dozen checkers, as indicated in the illustration. Before this col¬ umn set another checker on end, which you will shoot against the pile by making your finger slide forcibly along the length of its circum¬ ference. The checker thus shot will strike one of the checkers in the column and cause it to drop out completely, without, however, in the least affecting the equilibrium of the others. The entire column will descend upon the checker beneath without being deranged. In reality, the force of impulsion communi¬ cated to the checker which left the pile was not transmitted to the remaining checkers, which, 5 6 FUN WITH MAGIC true to the law of gravity, sank vertically to take the place left vacant. This experiment may be varied by means of a knife, with which a sharp horizontal blow may THE PILE OF CHECKERS. be struck against one of the checkers, compel¬ ling it to leave the pile, whose symmetry will, however, not be altered in consequence. This principle of inertia will furnish us with a number of experiments as interesting as they are conclusive. Upon a bottle lay a visiting or playing card, and on top of that a piece of money small enough to pass into the neck of the bottle. The coin should be placed just above the mouth of the bottle. Give a vigorous little rap in a hori¬ zontal direction upon the edge of the card and you will succeed in displacing it, while the coin FUN WITH MAGIC 7 will fall into the neck of the bottle. The fol¬ lowing phenomena were produced: the move¬ ment was too rapid to be transmitted to the piece of money, so the card alone was displaced, the coin necessarily falling without deviating from the line of its position. THE OBEDIENT COIN. Take a box of matches and remove the drawer. Hold the box in a horizontal position and place 8 FUN WITH MAGIC upon the middle of the top a small coin. In order to make the coin go inside without touch¬ ing it give it several light strokes on the side THE OBEDIENT COIN. which you wish it to enter. As soon as it reaches the edge, tip the box lightly, raising the end where the coin is until it is balanced upon the edge. Another gentle stroke of your finger and it will drop inside. FUN WITH MAGIC 9 When you strike the box you impart to it a movement which is not participated in by the coin, which remains stationary. In reality a retrograde movement is produced in the box, ending in drawing the box backward at the moment when the coin arrives at the edge. This little experiment is very interesting and easy of execution. THE INSENSIBLE COIN. Roll a strip of cardboard about 3 or 4 inches in length into a ring, holding it in shape with a pin. Then balance it upon the mouth of a bottle, and upon its upper side place a coin im¬ mediately above the bottle’s neck. When the whole is so arranged, try to remove the ring so that the coin will fall into the bottle. You will obtain this result by giving a lively stroke of your finger upon the interior of the ring, as indicated in the cut. The ring will fly off, while the piece of money, by virtue of its inertia not participating in the movement produced, will invariably drop into the neck of the bottle. It is absolutely necessary that you strike the circle from the inner side. FUN WITH MAGIC THE INSENSIBLE COIN. FUN WITH MAGIC II A CLEVER STROKE. Take a stick about one yard long- and in each - end stick a pin. This done, rest the stick upon the bowls of two pipes, which two persons hold by the hand, but in such a way that only the A CLEVER STROKE. pins touch the pipes. A third person strikes the middle of the stick with a sharp blow, breaking it without injuring the pipes in the least. Choose rather fragile pipes, those of clay answering the purpose very well. This gives greater mystery to the experiment. The explanation of the experiment is found in the fact that the blow has not time to propa¬ gate itself beyond the point where it fell. 12 FUN WITH MAGIC A COUNTER-STROKE. Upon the neck of a bottle place a cork ver¬ tically. The cork should be large enough to A COUNTER-STROKE. enable it to rest on the rim of the neck without sinking. Now strike the neck of the bottle sharply and you will see the cork tumble, not toward the other side of the bottle, but forward, in the direc- FUN WITH MAGIC 13 tion of the hand which gave the stroke. This is again an illustration of the principle of inertia. The rapid blow serves to push the bottle away from the cork before the movement can be trans¬ mitted to the cork itself. Few persons perform this experiment suc¬ cessfully the first time because an instinctive fear that they will break the bottle or injure their fingers prevents making the blow suffi¬ ciently strong. * BALANCING A KNIFE IN SPACE. This experiment is interesting and easy of execution. BALANCING A KNIFE IN SPACE. Take a rather large cork, of a champagne bottle if you have it on hand. ,Make a slit in it lengthwise, inserting to one-third the depth of 14 FUN WITH MAGIC the cork the blade of the knife which you have chosen. Then stick into each side of the cork the prongs of two forks, opposite each other, so that the prongs are perpendicular to the knife-blade. This done, you have only to suspend the tip of the blade in a loop of twine; the knife will remain in a horizontal position and can be swung to and fro without disturbing the equilibrium. A COIN BALANCED. Here is an interesting demonstration of the balancing of a body whose center of gravity is displaced by means of counter-weights. The point is to keep balanced in a horizontal position on the edge of a glass a piece of money which does not touch the glass save on its extreme edge. Take a quarter and place it between the teeth of two forks which overlap each other. Then rest the edge of the coin upon the glass and either bring the handles of the forks closer together or farther apart until the whole is balanced. The center of gravity will then be at the point of contact, and you can have a slight fluctuation without running the risk of derang¬ ing the equilibrium obtained. FUN WITH MAGIC 15 A COIN BALANCED, THE INCLINED PLANE. Take a piece of paper and roll it into a cylinder large enough to hold a marble, gluing it to¬ gether so as to retain the proper shape. Then close up the ends with a strip of paper as indicated in the illustration, first placing inside i6 FUN WITH MAGIC a marble. When your apparatus is dry set it upright at the top of an inclined plane formed by a little board or ruler resting upon a pile of books. You will then see the cylinder fall flat and rise again, and so on until it almost reaches the base of the plane. The effect is very curious and will be espe¬ cially so if you are enough of an artist to outline some design upon the cylinder. You FUN WITH MAGIC 17 will have a very original series of movements and will certainly amuse your spectators. THE WALKING CORK. Stick two knives into a cork, one in each side opposite each other so as to form a balance. THE WALKING CORK. i8 FUN WITH MAGIC Then into the base of the cork insert two pins deeply enough that they will not bend under the weight which they will have to support. Place the whole upon a flat ruler slightly inclined, and give it a light rocking motion. The weight of the apparatus will now fall upon the pin (A), while the whole turns upon that pin. The knife placed on the side B will tend to restore the apparatus to its first position, but the movement of oscillation continuing, the pin B will in its turn support the entire weight and the pin A will take its position at the other point A, indicated in the illustration. The walking cork will con¬ tinue its march along the assigned route, af¬ fording an illustration that all bodies are at¬ tracted by the earth and that disarranged from their usual position of equilibrium they become obedient to its solicitations. THE MYSTERIOUS APPLE. Pierce an apple so as to obtain two passages through it which will form a rather large angle about the middle, as indicated in the cut. If you have at your disposal two goose quills you can use them in making the passages more solid. Pass a piece of twine through the opening and FUN WITH MAGIC 19 THE MYSTERIOUS APPLE. 20 FUN WITH MAGIC you will be prepared to perform a little trick which will astonish all who are not initiated. Take the ends of the string between your hand and foot so as to control the tension of the string. You can then command the apple to descend or pause and it will execute your orders immediately. In reality, when you draw upon the twine the portion which is in the apple will press upon the angle formed by the two pas¬ sages, and with this pressure will hold the ball. On the contrary when you hold the line lightly you remove all rigidity and the apple will of course descend. AN AMATEUR PNEUMATIC MACHINE. A pneumatic machine is a necessity for cer¬ tain experiments, but as it is a comparatively expensive apparatus there are herewith given instructions for constructing a very good ma¬ chine at small expense which will answer for a number of interesting experiments with atmos¬ pheric pressure and vacuums. Get three rubber tubes: one io inches long with an exterior diameter of 2 inches and an interior diameter of i| inches (No. i); one 7 inches long with an exterior diameter of FUN WITH MAGIC 21 22 FUN WITH MAGIC inches and interior diameter of i inch (No. 2); one about 1 yard long" with an exterior diameter No. 3 of 2 \ inches and an interior diameter of 1 inch (No. 3). Divide the second tube into two equal parts, in a section of 45 degrees. Into one of the No. 4 divisions fit a hard wooden pipe whose shape is indicated in the illustration. This pipe is pierced lengthwise by a narrow canal. Cut a little win¬ dow into the hollowed out portion which will be closed up with an elastic rubber band firmly bound to the outside of the pipe. This band will serve the purpose of a valve, and should be placed on the beveled edge. (See the figures.) FUN WITH MAGIC 23 Then fasten this pipe to the large tube, num¬ ber one, which constitutes the body of the pump. To the other part of the second tube attach another pipe similar to that just described, but No. 5 whose rubber band is fastened to the side oppo¬ site the beveling. The first pipe serves as an exit, the second as a suction pipe. Finally fasten to the third tube one kind of muff or another, ac¬ cording to whether you wish to condense the atmosphere or make a vacuum. Construct a simple pedal with two boards fas¬ tened together with hinges as in the cut, and 24 FUN WITH MAGIC AN AMATEUR PNEUMATIC MACHINE. FUN WITH MAGIC 25 bear upon it with your foot. The air contained in the body of the pump tends to escape outside; so it raises the valve of the pipe number one and passes out; when the pressure ceases the large tube because of its own elasticity resumes the form it had at first and draws in air. This time the valve on pipe number two is raised and lets the air escape which has just filled up the body of the pump. If you attach to the second pipe the long rubber tube number three which has been inserted in a receiver, it is easy to see that after a few strokes of the pedal the air will all be sucked in and you will have a comparative vacuum. When you wish to have a machine for con¬ densing air you simply require a slight modifica¬ tion in the detail of the construction of the valve. 26 FUN WITH MAGIC Instead of arranging the rubber band as de¬ scribed make your valve with a band of rubber held by one side alone. You will have to be very careful to use exceedingly strong tubes. A BALLOON IN A VACUUM. Place a little toy balloon in a receiver, first moistening it slightly to render it more supple. A BALLOON IN A VACUUM. Under ordinary conditions there is an equilib¬ rium between the air found in the receiver and FUN WITH MAGIC 27 that contained in the balloon; but when you have a vacuum the balloon becomes inflated and, if the experiment is prolonged, ends by bursting, thus proving the power of the expansibility of gas. SUFFOCATION IN A VACUUM. Imprison a mouse in a receiver and begin to make a vacuum and you will soon see the little SUFFOCATION IN A VACUUM. animal showing all the signs of suffocation, a proof that animals' and people cannot live with¬ out air. 28 FUN WITH MAGIC EBULLITION IN A VACUUM. If we substitute for our mouse a glass filled with distilled or rain water, when the vacuum is made our water will boil, although ordinarily \ EBULLITION IN A VACUUM. a temperature of ioo degrees centigrade is nec¬ essary to make water boil. This phenomenon is explained in this way: the vacuum causes the bubbles of air in the water to escape from the liquid. They have little difficulty in doing this, because there is scarcely any pressure on the surface of the water. FUN WITH MAGIC 29 A VOICELESS BELL. Every one knows that sound is only a series of vibrations, which must have a ponderable A VOICELESS BELL. medium in order to be propagated; in other words, in a vacuum sound cannot be trans¬ mitted. Suspend a little bell in a receiver; in proportion as the vacuum is perfected the sounds will diminish, ceasing entirely when the rarifica- tion of the air is completed. 30 FUN WITH MAGIC THE VENTILATOR. Let us change our material and take some glass receivers open at both ends. If we place THE VENTILATOR. our hand over one of the openings and a vacuum is made, we cannot detach the hand. And not even an entire vacuum is necessary, because the FUN WITH MAGIC 3i subcutaneous structure would be injured in that case. It is by the rarification of the air that cupping- glasses are efficacious in cases of illness. Bits of paper are burned in small glass receivers and placed upon the skin; the air, while cooling, contracts and produces a partial vacuum. THE BURSTED BLADDER. Fit a light rubber film into a receiver and it will be seen that in proportion to the vacuum 32 FUN WITH MAGIC produced the rubber will expand and form a bal¬ loon in the interior of the receiver. If you firmly attach a well-stretched bladder over the top of the receiver, it will not be long THE BURSTED BLADDER. before it will begin to tear under the influence of the atmospheric pressure which bears upon it, as it loses its equilibrium when the vacuum is formed beneath it. FUN WITH MAGIC 33 RESISTING THE PRESSURE OF THE AIR. We shall now make another experiment which will teach us the better to appreciate the importance of the gravity of the air. Lay a 34 FUN WITH MAGIC piece of soft skin under the receiver, providing it with a hook. Make a vacuum and you will be astonished at the weights which will be nec¬ essary to detach the skin from the glass. If you have not a glass receiver convenient, RESISTING THE PRESSURE ' :? THE AIR. a wooden spool will do. Place upon one end a strong playing-card, to the middle of which is attached an iron hook. When the rarification of the air is completed, it will be necessary to sus- FUN WITH MAGIC 35 \ pend very heavy weights in order to loosen the card from the spool. COMPRESSED AIR. A reservoir of compressed air is necessary in performing several experiments with condensa¬ tion. Get a tinner to make you a pipe about ten COMPRESSED AIR. inches in diameter and a yard long, closed at both ends. You will have to be very careful to have the soldering well done so as to prevent any leak. Provide two openings as shown in 36 FUN WITH MAGIC the illustration, each furnished with a little tube, upon which is fitted a rubber tube from a yard and a half to two yards long. In order to fill this reservoir with condensed air you will have to use the pneumatic machine, employing the pipes in the second position de¬ scribed. You must be careful before com¬ mencing the experiment to stop up the upper rubber tube. When you think that the condensa¬ tion is sufficient, you can begin the experiment of raising a ball or a cork as indicated in the cut. THE EFFECT OF CONDENSATION. Take a wooden spool, hollow out one end and place in the groove a billiard-ball. When a FUN WITH MAGIC 37 rubber tube introducing condensed air is at¬ tached to the other end the billiard-ball will be raised. PULVERIZATION WITH PETROLEUM. With the aid of our apparatus for condensation we can perform various experiments in solder¬ ing which require a high temperature. We shall construct the following pulverizer: PULVERIZATION WITH PETROLEUM. b Place some petroleum into a bottle of the shape shown in the accompanying cut, and in- 38 FUN WITH MAGIC troduce into it a glass tube, fastening it some distance from the bottom. Seal it tightly and to the upper end of the tube fit a fixture of which a section is shown in the engraving. This has three openings, two horizontal and one connecting with the tube that is immersed in the petroleum. Attach the rubber tube to the reservoir and the pressure bearing upon the surface of the liquid will force the petroleum to rise to the fixture, where it will be expelled in the form of little drops; as they are mingled with the air it follows that the molecules of air at the same time are carried to a very high temperature. As a result a stream of intense cold is developed. This pulverizer may be used to purify the atmosphere of rooms simply by substituting for the petroleum some antiseptic liquid. A BAROMETER. Let us test the pressure exerted by the at¬ mosphere surrounding us with the aid of the familiar little instrument known as a barometer. We can construct it ourselves. Take a glass tube about one yard long and about one-fifth of an inch in diameter. Fill it with mercury, FUN WITH MAGIC 39 then tip it over into a basin containing the same metal, being very careful not to let in any air. The column of mercury will be arrested in its descent at about a height of 30 inches. This then measures the force of the pressure of the air, be¬ cause in the upper portion of the tube there is an 40 FUN WITH MAGIC absolute vacuum, and nothing resists the ascent of the mercury. So the weight of the air cor¬ responds to the height of the mercury. Suppose now that an interior section of the tube measures one square inch; we shall then have 30 cubic inches of mercury. Obtain the weight of one cubic inch of mercury and you will then be able to calculate the weight of the entire column. Knowing the extent of the surface of the earth you will be able to continue your com¬ putations with a view to arriving at some idea of the enormous pressure brought to bear upon it and upon us. We are not conscious of it be¬ cause the pressure is exerted in all directions and because it bears upon us in elastic fluids which balance it. We become so accustomed to the weight that during stormy weather we feel heav¬ ier, although the reverse is true, for when the barometer registers lower, the pressure has diminished, we have less weight to support. When we rise in a balloon the weight of the air becomes less apparent and at about the height of eight or nine thousands yards we experience such constraint that the liquids of our body, the blood, water and bile escape outside, being no longer sustained by the pressure, which is nec¬ essary for them. In this way we are apparently FUN WITH MAGIC 4i held to the surface of the earth, while the lofty heights of space are protected from our curios¬ ity. A SUCTION PIPE. There are many scientific recreations to be HI * 0. Vi, y > rj E —7 - - - * r- ■ - - -1 — - ..: -—, — ■--—* * A SUCTION PIPE. had in connection with the pressure of the at¬ mosphere which we have just tested. 42 FUN WITH MAGIC Take the hollow handle of a steel penholder or of a dipper and pour a little water inside it and let it boil until the air in the tube has been replaced by vapor. When the generation of the vapor is at its height introduce into the upper opening B, as shown in the figure, a little piece of cork, closing it tightly; oil it lightly so that it will slip easily. If you will cool the tube again, by putting it into a basin of water, for example, the steam or vapor is condensed, a vacuum is produced inside, and under the pressure of the atmosphere the little cork slips out. If you at¬ tach a bit of twine to the cork you can draw it back and repeat the operation; in proportion to the amount of water which escapes and the vapor which is formed you will see the cork reascend. ASCENT OF WATER IN A VACUOUS DE¬ CANTER. Fill a deep plate with water and place upon it a candle about four inches long. Light the can¬ dle and cover it over with a large-necked empty bottle. As soon as this is done you will notice that the flame of the candle begins to vacillate, then goes out, while the water rises into the bottle. FUN WITH MAGIC 43 Let us examine for a moment the causes of this simple phenomenon: the candle burning in the bottle consumes all the oxygen in the air, ASCENT OF WATER IN A VACUOUS DECANTER. producing a want of equilibrium between the pressure of the gas contained in the bottle and the atmospheric pressure. This last,' being stronger, operates upon the water in the plate, causing it to ascend until the pressure of the gas 44 FUN WITH MAGIC remaining in the bottle, augmented by the weight of the water, restores an equilibrium with the pressure of the liberated air. If you will repeat the experiment you will no¬ tice that the water will not always rise to the same height; this is because there is a greater or less amount of carbonic acid liberated when the candle is extinguished. THE SUBMERGED COIN. The preceding experiment may be emphasized by another: Place a coin in a soup-plate; by its THE SUBMERGED COIN. side stand an inverted glass, and add water until the coin is covered. You can then announce to your spectators that you are going to draw out FUN WITH MAGIC 45 the coin without touching it with your fingers. You can calculate upon great incredulity on the part of your hearers. Place on the stopper of a bottle a little plate containing some bits of paper and slip it under the glass, which takes the place of a receiver. Light the paper and wait. As soon as combus¬ tion is perfected you will see the water leaving the soup-plate and rising in the glass, while the coin is left absolutely dry on the bottom of the plate. You can then make good your promise of picking up the coin without wetting your fin¬ gers. This experiment proves the weight of the air. In reality if the foregoing phenomenon were not produced the air would escape during the com¬ bustion. But as soon as the materials on the floating cork have ceased to burn, the air be¬ comes cooler, and, in cooling, contracts, and in that way creates a vacuum under the glass. The atmospheric pressure acting upon the water forces the water to rise in the glass because of the difference in the degree of pressure. THE PERVERSE CORK. * Take a glass or metal tube closed at one end. Fit into the open end a stopper of cork or rub- 46 FUN WITH MAGIC ber which will close it hermetically; pierce the cork with a small hole so that it will be able to pass into the tube without difficulty, afterward covering over the hole with a bit of leather, THE PREVERSE CORK. which you will have to be careful to moisten be¬ fore making the experiment. Pass a piece of twine through the cork, as indicated in the illus¬ tration, so that you can draw it out. You are now ready to make another demon¬ stration of atmospheric pressure. Raising the FUN WITH MAGIC 47 little leather valve, force the cork to enter the tube until it almost reaches the middle. Then replace the valve and pull hard upon the twine to draw out the cork. But it will not come, for a vacuum has been made in front of it and the at¬ mospheric pressure prevents it from leaving. But if you will pull very gently at it it will offer no resistance, because the air will enter by the slightest interstices and so will destroy in part the exterior pressure. THE PRESSURE OF GAS. Take two small bottles and close them with corks. Pierce each cork with two openings, through which you will pass a glass tube curved to form, an elongated U, the extremities of the tube reaching just a short distance below the bottom of the cork. Fill one of the bottles three- quarters of its height with water and pass through the second opening in the cork a glass tube pierced at both ends and reaching to the bottom. This phial should be corked very tight¬ ly, if necessary using sealing wax. Into the other bottle place some chalk and fit into .the other orifice in its cork the end of a paper cornu¬ copia, into which you will drop a pellet of putty 48 FUN WITH MAGIC or of wax. Your apparatus thus disposed, you will introduce by the paper cornucopia some vin¬ egar or, better, some sulphuric acid, whose con- THE PRESSURE OF GAS. tact with the chalk will produce carbonic acid. Since the acid cannot escape by the cornucopia, which will be stopped up with the pellet, it will FUN WITH MAGIC 49 PRESSURE OF AIR 50 FUN WITH MAGIC pass through the glass tube into- the other bot¬ tle and there collect upon the surface of the water. A moment will come when the pressure brought to bear on the water will be very strong, when the water will rise by the vertical tube and gush forth in the form of a jet. This experiment may be given in a simpler form. Simply take a bottle and fill it two-thirds full of water and cork it. Make two openings in the cork, passing through one of them a tube which shall reach to the bottom of the phial and through the other one, which will come just to the surface of the liquid. Surmount the second with a receiver. Spread the cork with wax to prevent the air from penetrating. If you will pour water into the receiver it will penetrate into the phial and cause the water-level to> rise. The air will be pressed and will bear upon the mass of liquid, finally causing it to escape by the other tube in a jet more or less strong according to the strength of the pressure exerted. AN EGG AS A STEAM ENGINE. Here is a very interesting little recreation which does not require much apparatus in order 1 o present a scientific demonstration. Set up the FUN WITH MAGIC 5i little structure shown in the cut, a few small boards being sufficient for its construction. ABCD will be the floor; EG and FH two up¬ right pieces joined above by a crosspiece GH. 1 5 AN EGG AS A STEAM ENGINE. The height of the upright pieces should be about 5 inches and they should stand about 3 inches apart. 0 OF iU- LIB. 52 FUN WITH MAGIC Into a block of wood about -J inch across and -J inch high stick a strong pin, inserting the point just a short distance. Then place the block of wood so prepared in the center of the little plat¬ form between the upright pieces; into the cross¬ piece insert another pin; the two pivots so formed will serve to hold the egg. Prepare your egg for its novel function as a steam engine by first emptying it through a small aperture L; then make two other openings, N M, to which you will glue two little paper tubes disposed as indicated in the illustration. Through the opening L introduce a little cold water, close the opening with a bit of gummed paper and set your egg in position, balancing it on the two pin points. The flame of a candle or of a lamp burn¬ ing feebly will suffice to set the egg in motion. In reality steam is formed within the egg, and not being able to escape except by the openings N M brings a pressure to bear on the side oppo¬ site the opening. This motion produces a ro^ tary movement which is communicated to the egg- THE IMAGINATIVE SWIVEL. It is not very difficult to make this swivel and only requires a little patience. Into a good cork, FUN WITH MAGIC 53 from a champagne bottle, for example, make three incisions of different sizes, as indicated in THE IMAGINATIVE SWIVEL. the cut. Put a teaspoon into each incision in such a way that the bowl of each spoon faces the 54 FUN WITH MAGIC cork at an angle of about 45 degrees. On the side of the cork stick three forks opposite each other so as to obtain a perfect equilibrium. In the center of the lower surface of the cork insert a needle and place the whole upon an inverted glass which is covered over a bottle. The swivel should maintain its balance on the point of the needle. Before commencing the experiment you must set the bottle on a tray or a plate. After giving a light impulse to the apparatus by pouring water into the spoons you will obtain a contin¬ uous movement, which will be due to the pres¬ sure of the water upon the bowls of the spoons, these acting as screws, moving in a direction con¬ trary to the pressure exerted. AN EXPERIMENT WITH LOCOMO¬ TION. The pressure exercised by heavy liquids may be tested in another way by filling an empty sar¬ dine box with water. Place it on a piece of board and set the whole in a tub of water. You must previously have made a slight aperture in one of the sides of the box, which can be closed with a small wooden peg. If you will remove the plug a stream of water will gush out, and the whole FUN WITH MAGIC 55 will take on a movement contrary in its direction to the flowing of the water. This is what has taken place: In a state of repose the liquid ex¬ ercises an equal pressure on the sides A and B, AN EXPERIMENT WITH LOCOMOTION. but when the opening is made the pressure makes the water flow at B and destroys the equilibrium at the side A, which withdraws un¬ der the pressure. You can give this experiment a more amusing aspect by constructing a little boat and filling it with water instead of using the sardine box. AN HYDRAULIC SCREW. Purchase a simple clay pipe and make the fol¬ lowing metamorphosis with it: Close the mouth 56 FUN WITH MAGIC with a bit of sealing wax and pierce the side with the point of a knife, suspending the pipe by a string, as shown in the illustration, the string be- AN HYDRAULIC SCREW. ing attached to it with wax. If now you will pour water into the pipe it will begin to turn in a contrary direction to that of the stream of water, which will escape from the tiny opening FUN WITH MAGIC 57 which you have made in the end of the handle. This is due to the pressure exercised by the water upon the portions of the pipe opposite the opening by which it escapes. A SCREW IN THE AIR. Fasten a needle, the point in the air, to the bottom of a basin with a bit of sealing wax. Ar¬ range an egg-shell, a third of which has been cut off, in the following manner: Pierce the upper end with two little holes, into which insert two straws, each terminating in a right angle and held in place by sealing wax. Around the open end of the egg glue three or four pieces of money 58 FUN WITH MAGIC in order to keep it in balance. Then set the shell thus prepared upon the point of the needle. Fill the basin with water and with a straw blow the air beneath the egg-shell; this air rises, is condensed above and in escaping by the little paper tubes gives a rotary movement to the whole apparatus. This is the same phenomenon as that produced by water pressure. A SCREW BY HOT AIR. During cold weather the hot air which escapes from a stove may be utilized in a number of lit¬ tle experiments. Trace a spiral, as indicated in the cut, upon a card or strong paper. Then cut it out and hold¬ ing it up with a pencil or a pointed stick of wood, expose it to the heat of a stove or of a furnace, and you will immediately notice it taking on a rotary motion. This movement will be caused by the column of air which is found beneath the fire and which occasions by its reaction a pretty strong ascending movement. If you do not wish to hold the pencil or the stick in your hand the spiral may be attached to a piece of wire and idstened to the pipe or some other support. This experiment may be rendered more en- tea<- FUN WITH MAGIC 59 tertaining by making a wheel of paper with pad- A SCREW BY HOT AIR. dies like a screw and mounted upon a horizontal axis, to set a puppet in motion. A LITTLE CANNON. It is well known that the tension of steam is considerable, and it is easy to make the follow- 6o FUN WITH MAGIC ing experiment in illustration of it successful: Buy a little hollow steel or iron penholder and fill it one-third full of water. Then cut out a A LITTLE CANNON. stopper for the open end by sinking it into a piece of potato, and pass the tube through a cork, placing it in a slightly sloping position. FUN WITH MAGIC 61 Beneath the lower extremity, which contains the water, stand a lighted candle or lamp, and you will soon hear a sound, the stopper will be forci¬ bly ejected from the penholder by the power of the steam which has been generated. WEIGHING GAS. Certain gases weigh much heavier than air; of these one is carbonic acid gas. This can be proved by constructing scales for the weight of gases, which is not difficult. Twist a piece of brass wire into the required forms as indicated in the accompanying illustration. One of the scales may be made with a strong cardboard box, the other with the lid of a little round box; suspend the whole by a piece of twine and secure equilibrium by placing a few grains of sand in the side designed for the weights. The manufacture of the gas is extremely sim¬ ple, merely requiring that you should pour some sulphuric acid over chalk, receiving it into a bot¬ tle from which it will not escape, since it is heav¬ ier than the air. When conducting this gas into the cardboard box you will see the latter de¬ stroying the equilibrium first obtained, thus demonstrating that the gas is certainly heavier 62 FUN WITH MAGIC than the air. Some curious variations of this ex¬ periment may be made. WEIGHING GAS. FUN WITH MAGIC 63 THE MAGIC WHEEL. The accompanying cut represents the form THE MAGIC WHEEL. * given to the wheel. Cut a stout piece of card¬ board into octagonal form and through its cen- 6 4 FUN WITH MAGIC ter pass an axis held in a norizontal position by means of two upright steel wires upon which its ends rest, and which are sunk into a piece of wood. Upon each of the eight sides of the wheel glue a paper cornucopia, all the cornucopias of the same size, and when they are dry pour into them some carbonic acid gas. The wheel will immediately begin to rotate, to the astonish¬ ment of your spectators, for the acid being color¬ less, no one uninitiated can imagine what causes the wheel to revolve. THE RINGS OF SMOKE. Have you ever noticed that when the air in a room is perfectly calm tobacco smoke will rise in an almost vertical direction? And have you ever dreamily watched the blue or gray figures traced in the air by the smoke of a cigar, and remarked that it rises capriciously, signifying that the surrounding atmosphere is calm? In reality, the least agitation of the air has an effect upon the fantastic course of the rings of smoke. This fact becomes the foundation principle of a very interesting recreation. As material take a cardboard box in the lid of which you have pierced a round hole about FUN WITH MAGIC 65 2 \ inches in diameter. Inside the box place THE RINGS OF SMOKE. two sheets of blotting paper one of which has been impregnated with muriatic acid and the 66 FUN WITH MAGIC other with ammonia in an equal quantity. Instantly white smoke will be formed which will escape through the opening and rise toward the ceiling. With your two hands make a series of pres¬ sures on the sides of the box and the smoke will emerge in the form of delicate rings, the result of the disturbance of the air within the box. The same effect can be obtained by the use of tobacco smoke but the rings endure longer when produced as just shown. THE MICROPHONIC STICK. Here is a curious illusion in accoustics based on the conductibility of sound through wood. Take a long stick, and at one end place a real watch and at the other a toy watch. If you will set your ear against the latter it will appear to be going; you can distinctly hear the ticktack, a fact which will produce the illusion that it is a real watch. The sound of the ticking has been transmitted through the wood because of the conductibility of wood. In default of a toy watch you can simply place your ear at the bare end of the stick and you can then hear the ticking of the watch at the other end just as if it were beside your ear. FUN WITH MAGIC 67 With this experiment you can perform a little THE MICROPHONIC STICK. trick; conceal the real watch under a cloth and place the toy in full view at the other end of the 68 FUN WITH MAGIC stick. To those uninitiated the ticking to be heard will appear marvelous. THE THREE COLORS. That liquids are of different densities may be easily proved by taking a glass and pouring into THE THREE COLORS. it successively water colored blue, ordinary oil, and alcohol of a red hue. These three liquids will remain stationary in layers and present to the eye the colors of the national flag. Then call attention to the fact that the density of water FUN WITH MAGIC 69 being* 1, the densities of the olive oil and of the alcohol are .0915 and .0795 respectively for the three liquids superpose themselves in the order of their diminishing density. A PICTURE OF A VOLCANO. This is another experiment based on the den¬ sity of liquids. Pour some wine or colored alco- A PICTURE OF A VOLCANO. hol into a bottle, which will then be sealed with a cork pierced by a slender tube, a straw or a quill. Then sink the bottle very cautiously into a glass bowl filled with water and you will soon observe the liquid escaping and mounting to the 70 FUN WITH MAGIC surface of the water, describing spirals which resemble smoke and which present a very strik¬ ing likeness, considerably diminished, of a vol¬ cano. COMPLIMENTARY COLORS. Upon a sheet of paper draw two rectangles, one colored red and the other green; at some A c : e ; B COMPLIMENTARY COLORS. distance from the rectangles draw two large dots as indicated in the cut, C C. Then against the line marked A B hold a rectangular plane about as thick as a playing card and from io to FUN WITH MAGIC 7 ^ 12 inches in height; and, placing its upper end between your eyes, fix your gaze on the paper. You will soon see the two dots approaching each other, finally blending, while the red rectangle will gradually disappear, being little by little absorbed by the green rectangle. This curious optical experiment is based on complementary colors. It is well known that the color white is composed of the seven colors, red, orange, green, yellow, blue, indigo and vio¬ let. But these seven colors may be resolved into three: red, yellow and blue, so that either one of these three if mixed with the two others will form white. Thus green is the complement of red, that is to say, green and red will form white since green is produced by the union of blue and yellow; blue is the complement of orange (com¬ posed of red and yellow); and violet is the com¬ plement of yellow (composed of red and blue). You can make the same experiment employ¬ ing other complementary colors. THE RECOMPOSITION OF LIGHT. We have seen in the preceding experiment on complementary colors that light is formed by the union of seven colors. When a ray of light is 72 FUN WITH MAGIC THE RECOMPOSITION OF LIGHT, FUN WITH MAGIC 73 passed through a prism it is decomposed and the image received presents the colors of the rain¬ bow. Now in physics there is an apparatus which reproduces the white light. It is a disk upon which the colors of the spectrum are painted and which one turns rapidly. The im¬ pression received in looking at the disk in motion is the absence of ail color; the eye per¬ ceives white light. Here is a way of performing that experiment without any apparatus save a round card and a piece of twine. Upon the card paint the colors of the spectrum in the following order, repeating them four or five times: red, orange, yellow, green, blue, indigo, violet. Paint them in the form of cones with the apex of each cone in the center of the card, and in the following propor¬ tion as to size: red 2J, orange 1, yellow 2^, green 2, blue 2^, indigo ij. Now through one of the diameters of the card bore two holes, through which draw a string, knotting the ends together. Then pass the string over the middle finger of each hand and having set the disk revolving, alternately make your hands ap¬ proach each other separate. You will thus impart a strong movement to the disk and will be able to reproduce a white light. 74 FUN WITH MAGIC THE PHANTOM PIN. In studying the properties of the reflection of light there are numberless interesting experi- THE PHANTOM PIN, FUN WITH MAGIC / o ments to be performed. A few are herewith pre¬ sented. Take a cork and cut it into the form of a disk of about the thickness of an inch. In its center stick the point of a pin. This done take a glass about three-quarters full of water and place the cork upon the surface of the liquid with the pin below. Now if you will look at the cork from above you will not see the pin but if you will alter your position and diminish the sense of the visual ray by placing the eye on a parallel with the table on which the glass rests you will perceive a pin above the cork. This phenomenon is the result of the total reflection which has been produced. The pin is reflected on the surface of the water and the visual ray, coming just to that level, sees the pin exactly as if it were upon the cork. AMPHITRITE. In some museums there are shown a variety of phantoms which present very remarkable illu¬ sions. One of these is the spectacle -of a woman who appears to emerge from the water, rises and moves about in the air without any visible means 76 FUN WITH MAGIC of support. She seems to be completely isolated in space; she revolves, sometimes accomplishing AMPHITRITE. a perfect circle, moves her legs and her arms, often very gracefully; then, after numerous evo- FUN WITH MAGIC 77 lutions in all directions, assumes an erect posture and rapidly descends, appearing to plunge back into the ocean. This spectacle always produces a very palpable illusion and profound astonish¬ ment. This is the way in which it is done: Behind a sheet of muslin well stretched is placed a piece of scenery, D D, representing the sky and clouds, while below on a horizontal plane is a curtain which serves as the ocean. In front in a line with G G there is a mirror without tin-foil inclined to an angle of about 45 degrees. Below this mirror stands a round table moving on a pivot, upon which lies the actress who takes the part of Amphitrite. In order that the various movements may be executed, the table is revolved, reflecting the image of the woman brilliantly illuminated in the glass, and the spec¬ tators situated at S, will see her before the cur¬ tain at D D. When it is desired to make the illusion disappear the table, which glides upon rails, is drawn away and Amphitrite seems to sink into the waves. It is in this way that the spectacles at the theatres are produced, and very curious similar optical illusions may be obtained at home by re¬ ducing the construction of the apparatus to the 7 « FUN WITH MAGIC simple proportions of a toy theatre with pup¬ pets. ILLUSIONS IN OPTICS. A large number of experiments may be made by availing one’s self of optical illusions. For example, ask some woman wearing a high hat to indicate its height on the wall or a piece of furniture, and nine times out of ten she will make it a third taller than it really is. Fig- Fig. 54 - ure 53 represents two triangles. Inquire of some one in which of these the center is more FUN WITH MAGIC 79 nearly shown by the dot, and anyone will point to the triangle A; while in reality it is the triangle Fig. 55 - B, as may be proved by a pair of compasses. It Fig. 56. is the same with the succeeding figures. The two parallelograms A B are absolutely equal although A appears to be larger than B. The 80 FUN WITH MAGIC two lines A and B are of the same length but ILLUSIONS IN OPTTCS. B seems about a third shorter than A. The sides A B, C D, B D, etc., and B E, A M, E M, FUN WITH MAGIC 81 etc., are equal while it appears to the eye that the surface A B E M is longer than the square A B C D. For the experiment with the circle, trace upon a sheet of paper a series of circles closer and closer together as they approach the center. Then place the paper on your thumb, revolving it horizontally and it will appear that the circles are revolving; the illusion will be complete. The last experiment in this series is shown by the figures of the three men in the illustration; which is the largest, the first, the second or the third? Try to find out by means of the naked eye and it will seem at first that the last is the tallest. Measure them with the points of a com¬ pass and your illusion will be dispelled. Begin¬ ning with the foremost the figures decrease in height. A SIMPLE EXPERIMENT WITH STATIC ELECTRICITY. We shall now have some experiments with electricity which are easy of execution. A piece of paper will enable us tQ perform the first experiment with static electricity. Take a strong piece of white paper and heat it lightly so 82 FUN WITH MAGIC as to expel every trace of humidity. This done, rub it with flannel or a cloth, although the flan¬ nel is preferable, or you can use the palm of your Fig. 59- hand if that is dry. Now hold the flannel near the paper and you will see that the former is attracted, a proof that the two bodies are charged with the contrary poles of electricity, because they both attracted a light body not electrified. You can verify these facts very simply. When the paper has been rubbed, tear it into two pieces and then try to place their edges together. However, since both are charged with electricity of the same pole, they will repel each other. Hold a pen near one and all its electricity will FUN WITH MAGIC 83 escape into the pen, making- the paper quiver slightly in doing so, and then, being no longer charged with electricity, it will be attracted by A SIMPLE EXPERIMENT WITH STATIC ELECTRICITY. the other piece of paper. In a dark room an electric spark will be visible. Here is another way of showing that the paper has been electrified by the friction. Bal¬ ance a pencil on the edge of a table. If you will approach with the paper which has been rubbed you will see the pencil inclining toward it, per¬ haps losing its balance and falling. MAGNETIC ATTRACTION. Provide yourself with a simple magnet, place it upright as indicated in the figure, fastening it to the table with some wax or gum. Then take a steel needle and a woman’s hair, tying each 8 4 FUN WITH MAGIC end of the needle with an end of the hair. Stand in front of the magnet, at a distance of about MAGNETIC ATTRACTION. i-io of an inch, a pin, to the middle of which you will glue the middle of the hair folded in two. The needle will be attracted by the mag¬ net, but being held by the hair will remain sus¬ pended by the attraction. This experiment, inexpensive and interesting, can be successfully performed with the exercise of a little patience. THE MAGNETIC SPECTER. Take a piece of paper about ten inches square and coat it over with table or castor oil, the lat- FUN WITH MAGIC 85 ter being preferable. Upon this then pour out a number of iron filings, laying a magnet over them. In gently separating the magnet from THE MAGNETIC SPECTER. the paper you will obtain what in physics is called a “magnetic specter.’’ A design is formed as indicated in the illustration which may be preserved an indefinite time because the filings will adhere to the paper by means of the oil. ANIMAL MAGNETISM. The following very simple apparatus will serve to verify the fact of animal magnetism in 86 • FUN WITH MAGIC an experimental way. Stick a needle into a cork, the point in the air. Upon this as a pivot lay a ANIMAL MAGNETISM. sheet of paper which should be perfectly bal¬ anced in a horizontal position. If now you will FUN WITH MAGIC 87 place your hand above the paper you will observe it manifesting a rotary movement, changing its position either to the right or to the left. This motion is caused by the magnetic influence of the hand. PRINCIPLE OF A GALVANIC BATTERY. A dozen pennies and as many circular pieces of cloth and zinc are the only materials necessary PRINCIPLE OF A GALVANIC BATTERY. for constructing a galvanic battery.. Form a pile with the three, placing down first a zinc piece, then a penny, and lastly a circle of the cloth and so on until the top, which will end with a penny. 88 FUN WITH MAGIC Bind all together with a string and steep it in very strong vinegar to which may be added a few drops of acetic acid, although that is not necessary if the vinegar is sufficiently good. Attach to the zinc piece at the bottom of the pile a piece of brass wire, and another to the penny at the top, in that way obtaining two conductors the one for negative electricity the other for positive electricity. Naturally the current will not be very strong but it will nevertheless have enough force to perform the following experi¬ ments successfully: Unite the two wires on the tongue; a light pricking sensation will be felt. Unite the wires above a mariner’s needle and it will deviate from its position. Lastly make the wires approach each other in a dark room and tiny electric sparks will be visible. . A BATTERY WITH A LEMON. Take an ordinary lemon and with it you can make an electric battery. Slice off one end leaving about two-thirds of the lemon; sink the blade of a knife into each compartment so as to destroy the minute inte- FUN WITH MAGIC 89 rior fibres, being careful however not to cut into the walls of the different compartments. Set the lemon in an egg-cup or a glass. Then prepare A BATTERY WITH A LEMON. tiny pieces of copper about four inches long, or, in default of a sheet of copper take copper wire; make zinc pieces of the same length. Place a piece of zinc and a piece of copper in each com¬ partment, not allowing them to touch each other. With a very fine copper wire you will then tie the zinc piece of one compartment to the copper piece of the next throughout the lemon until there remains one free piece of each 90 FUN WITH MAGIC metal. You will thus have a positive pole of copper and a negative pole of zinc. This battery of many elements, for it has as many elements as there are compartments in the fruit, may be utilized, among other experi¬ ments, for demonstrating the deviation of the magnetic needle, the decomposition of water, etc., etc. You can test its action by placing the two poles upon your tongue, thus producing a salty taste, which will indicate to you that some electricity has been liberated. The application is simple: the juice of the lem¬ on being acid the zinc is attacked and frees hy¬ drogen, which, combined with the oxygen of the liquid, attacks in its turn the copper. As in every chemical action, there is a liberation of electricity, it is only necessary to receive it. Such is the principle of the lemon battery. ELECTRIC ATTRACTION AND REPUL¬ SION. It is well known that poles of the same name repel each other, and that those of contrary names attract each other; in other words, nega¬ tive or positive electricity attracts electricity of the opposite sign and repels that of the same sign. FUN WITH MAGIC 9 i This principle may be demonstrated by con¬ structing a little toy which will at the same time be interesting to see in operation. ELECTRIC ATTRACTION AND REPULSION. Plant a needle into a cork by way of a pivot; then take two old corset steels, or, if they are not convenient, the spring of a clock, and mag¬ netize them by means of a magnetic bar or a machine. In the middle of one of the steels make a slight indenture so that the needle can turn freely in the cork without danger of falling. 92 FUN WITH MAGIC You will then have constructed a mariner’s needle or compass. Next cut out four little paper dolls, two men and two women, and place a pair on each steel, one person at each end. Now every time that you present one of the men to the other they will be repelled, while if you present a woman to him they too will be attracted. The explanation is simple. You must only be careful to place the men and women on the con¬ trary poles, the men on the positive poles and the women on the negative, or vice versa. You will then be able to demonstrate the principle mentioned above. An amusing variation may be had by naming the dolls for people present and by illustrating antipathy as well as affinity between the men and women. METALLIC COLORS. The production of the circles of Nobili form a very simple and very entertaining electric- chemical experiment which requires but two batteries or else a magnetic-electrical machine, in order to insure success. FUN WITH MAGIC 93 The best results in variety and brilliancy of color are secured by the use of a Bunsen or a Grenet battery. Place in a common saucer or plate a piece of steel or nickel which by means METALLIC COLORS. of a brass wire is put into communication with the negative pole. The bottom of the plate is in a similar manner made to communicate with the positive pole. Then pour over the steel a solution of acetate of lead. The wire connecting with the saucer should be very near the steel without touching it, as indicated in the cut. In a moment a speck of color will appear upon the metal and soon after will expand rapidly, form- 94 FUN WITH MAGIC ing into concentric rings of prismatic hues with the most curious effect. With a little practice you can determine the Fig. 68. time necessary for obtaining the best colors and for varying the effects thus obtained. You must be careful to wash the metal sheet at the conclusion of the experiment and to dry it. The colors are due to the decomposition of light by the excess of peroxide of lead disposed upon the surface of the metal. In order to ob¬ tain the best effects the metal should be carefully polished and the solution of lead filtered with care. FUN WITH MAGIC 95 You can produce a variety of forms in color by placing upon the metal sheet brass wire curved into the desired shapes, letters or fanciful designs. The circles of Nobili resemble Newton’s rings; the colors are strong and of an agreeable appear¬ ance. That celebrated physician discovered the phenomenon in 1826; since that date different variations have been reported. They are much in use for the ornamentation of small objects like buttons, trinkets and jewelry. THE WEIGHT OF STEAM CONTAINED IN THE AIR. Take an ordinary bottle and cork it with a cork which has previously been pierced with two holes. Through one of these pass a tube A, which will just reach to the lower surface of the cork, and through the other the tube C, which will go to the bottom of the bottle, and which will be connected by a rubber tube B to the glass cylinder O. The cylinder is filled with powdered pumice-stone steeped in sulphuric acid. The apparatus thus disposed is ready to operate. When you wish to compute the amount of vapor in the atmosphere, weigh the 9 6 FUN WITH MAGIC tube O, containing the pumice-stone, and re¬ place it in its former position; then fill the bot- A a THE WEIGHT OF STEAM CONTAINED IN THE AIR. tie with water and turn it upside down. The liquid will flow out by the tube A and the air FUN WITH MAGIC 97 will enter through the tube C, relinquishing its humidity in the cylinder O. When the bot¬ tle will be entirely empty you will only need to weigh the cylinder a second time and you will have the weight of the humidity contained in a pint of air. A simple calculation will en¬ able you to establish a proportion. METALLIC ARBORIZATIONS. Place some crystals of sulphate of iron in a flask containing a solution of silicate of potas¬ sium. After a day of repose there will be pro¬ duced an arborescent crystallization which will give birth to dark green branches. Sulphate of cobalt will produce rose-colored branches, and sulphate of copper will produce branches of a beautiful blue tint. INSTANTANEOUS CRYSTALLIZA¬ TIONS. Prepare two very strong solutions, one of hyposulphite of soda and one of acetate of lead. Pour the first solution gently into a phial, then the second over it so as to form an upper layer without mingling with the solution be- 98 FUN WITH MAGIC neath it. When all is well settled pass a crystal of hyposulphite of soda into the solutions by means of a string, and it will traverse the upper layer of lead without disturbing it, but as soon as it penetrates the hyposulphate it will crystal¬ lize that salt immediately. You can proceed in the same way with the acetate of lead, and it will be crystallized in its turn. VOLCANOES IN MINIATURE. Place in the bottom of a large porcelain bowl VOLCANOES IN MINIATURE. some nitrate of lead, over which pour sal am¬ moniac. Numberless little elevations will im- FUN WITH MAGIC 99 mediately be formed, from whose summits dust and vapors will emerge, presenting a striking likeness to volcanoes in eruption. A RUDIMENTARY GAS BURNER. Fill a round tin box with sawdust and bits of A RUDIMENTARY GAS BURNER. thick blotting paper, using for your box an old shoe-blacking box or something similar which 100 FUN WITH MAGIC will have a height of at least 2 inches; close it as tightly as possible and introduce into the lid a small metal or glass tube, letting it pene¬ trate into the box a distance of about one-third the latter’s height. Seal the juncture with putty. Then place the box upon two supports and below it light a candle. Soon the sawdust and blotting-paper, being overheated, will liberate alcoholic vapors and combustible gases. Hold a lighted match to the top of the tube and you will see the gas ignite and continue to burn. CAMPHOR IN WATER. If you will throw some bits of camphor upon water, you will find that they will immediately revolve with great rapidity, the one about the other. These movements are due to the diminu¬ tion of the superficial tension of the liquid in the vicinity of the camphor. To stop them, simply toss a drop of oil upon the water and you will have a calm surface. You can utilize the camphor in a very enter¬ taining amusement. Construct a small boat of paper or cardboard and to the lower part of its stern attach a bit of camphor. Set afloat upon the water; it will perform a series of evolutions FUN WITH MAGIC IOI which will be utterly inexplicable to those who have not been informed of its means of locomo¬ tion, and who will long search in vain for the secret. HOW TO MAKE ICE. Stand a receiver containing the water which is to be frozen in a pail, and around it pour a mixture of 8 parts of sodium sulphate with 5 parts of hydrochloric acid. This will produce a cold of about 15 to 18 degrees below zero. Or you can make a solution of 1 part of ni¬ trate of ammonia with 1 part of water. In winter, when you have the snow at your disposal, you can take 1 part of snow to 1 part of calcium chloride (common sea salt) and ob¬ tain a temperature of 20 degrees below zero. HOW TO CUT A BOTTLE WITH A PIECE OF TWINE. First paste two paper cushions around the bottle, one on each side of the place which you wish to cut. The cushions should be made by gluing successive layers of paper one on top of the other and leaving a groove ‘between the 102 FUN WITH MAGIC two cushions for the twine. Take the two ex- HOW TO CUT A BOTTLE WITH A PIECE OF TWINE. tremities of the string, one in each hand, and move it briskly to and fro so as to heat the FUN WITH MAGIC 103 glass below. When you think the latter has become sufficiently hot, plunge the bottle into cold water, which you will have within your reach, and you will see that it is neatly severed where the twine exercised its friction. You will require a greater or less degree of heat accord¬ ing to the thickness of the glass. This proc¬ ess is infallible. There is another way of obtaining the same result; it is by dropping water on the string as soon as the necessary amount of heat has been secured. You will have to be careful to moisten the twine thoroughly, and you can then be cer¬ tain that the break will be as clean cut as by the preceding method. THE BRIDGE OF ASSES. All pupils are familiar with the famous theo¬ rem in geometry which is known as the Pons Asinorum, or “Bridge of Asses/' and which runs thus: “The square on the hypotenuse of a right-angled triangle is equal to the sum of the squares on the other two sides.” Here is a way of establishing its truth, a way which, if not strictly pedagogical, is neverthe¬ less accurate; 104 FUN WITH MAGIC THE BRIDGE OF ASSES. Fig- 74 - FUN WITH MAGIC 105 Trace a square upon a piece of cardboard or stout paper and divide it into 49 equal smaller squares. This done, cut it out along the lines indicated in the illustration by the heavy mark¬ ing, and remove from the center a square, which you will add to the square D. Then construct the figure shown in 74, when you will have a right-angled triangle ACD, formed by the sides of the three squares; and the sum of the two small squares erected upon the two sides of the triangle will be equal to the large square erected upon the hypotenuse AD. You have in reality: One square of 9 parts. One square of 16 parts. The two equal 25 parts. And the large square C contains 25 parts. Sa your theorem has been established. ANOTHER WAY OF DEMONSTRATING THE SAME THEOREM. Draw four similar and equal triangles in a square ABCD, and cut them out and arrange them as indicated in the first of the accompany¬ ing illustrations. You will then have in the middle a vacant space forming a large square, io6 FUN WITH MAGIC which will have for one of its sides the hypote¬ nuse of the right-angled triangle AEB. Trace the outlines of this square and rearrange the ANOTHER WAY OF DEMONSTRATING THE SAME THEOREM. triangles, placing one against the other HCE against AEB, and CDG against BFG, obtaining the second figure in the illustration. The cov¬ ered and the uncovered parts of the two squares have not changed in extent, but this time the part not covered is formed by the two squares FUN WITH. MAGIC 107 2 and 3, which correspond to those constructed upon the two other sides of the triangle AEB. This very simple demonstration has the advan¬ tage of being-able to be applied to any triangle whatever. RE-ENTERING ANGLES. Take two rectangular sheets of paper of the same size and fold both into four equal parts, i 2 3 h __ 1 2 3 4 Fig. 76. Fig. 77. the one lengthwise and the other crosswise as shown in the cuts 76 and 77. The papers thus folded, detach one of the folds, that is, one- fourth part, A, of each paper. io8 FUN WITH MAGIC The question now at stake is the exact cov¬ ering of one of the remaining surfaces by means of the other, the latter being cut for the pur¬ pose into two identically equal portions. Fig. 78. Fig. 79. RE-ENTERING ANGLES. The two sections A being detached, the ques¬ tion is solved if you will take the sheet which you are going to use as a covering for the other, and fold it anerw into four equal parts, but this time in the direction opposite to that in which it was previously folded, as illustrated in the cut 78. Then cut it out, following the dotted line FL, and you will have two precisely equal divi¬ sions. FUN WITH MAGIC 109 You can now cover the other sheet of paper by simply fitting the angles into each other, placing the face of the angle a' into the face of the angle a, the angle b' into b, c' into c. This done, the two surfaces will be absolutely similar and may be covered the one over the other. In this example the figure 78 has been used to cover 77, but 77 can be made to cover 76 in exactly the same manner. The operation ended as just described, the part M of the figure 78 will correspond to M' in figure 79, and O to O'. TRACING PARALLEL HATCHINGS. Linear and architectural designs frequently require the tracing of parallel hatchings; here is a way of doing so with the greatest regular¬ ity. Take a flat ruler AB and a square CDE. In the ruler make an indenture hijf, the length i f being somewhat exceeding the side CD of the square, and being increased according to the distance which you wish to have between the hatchings. Your materials so arranged, pro¬ ceed as follows. Place your square in the niche made in the ruler so that it will occupy the position m'h'E; no FUN WITH MAGIC A A' TRACING PARALLEL HATCHINGS, FUN WITH MAGIC hi you will trace your first line i'E along the length of the square h'e without budging the ruler. Then slide your square along until D touches g' and trace your second line h"E'. Now let the square remain stationary and first move your ruler, afterward bringing the square into posi¬ tion for the third line, and continue in this way, alternately moving the square and the ruler. You will obtain perfect hatchings and without any danger of having them badly drawn. HOW TO DRAW A SPIRAL. The geometrical process for drawing a spiral by means of a compass is extremely lengthy. A very practical and easy method is herewith given. Take a wooden or cardboard cylinder A, whose diameter is equal to one-fourth the dis¬ tance of the spires which you wish to draw. Around this cylinder wind a twine B, one end being fastened to the cylinder and the other to a pen or pencil, whichever you wish to use. It is now only necessary to revolve the pencil either to the right or to the left according to the direction you desire the spiral to take, keep- 112 FUN WITH MAGIC ing the string tense, and a spiral of perfect reg¬ ularity will be produced. The accompanying HOW TO DRAW A SPIRAL, FUN WITH MAGIC ii 3 cut will illustrate with ease how this may be ac¬ complished. THE PERSPECTOGRAPH. This simple instrument, the invention of a Frenchman, renders the tracing of a design a very easy matter, its principal advantage being the fact that it makes faults in perspective ab¬ solutely impossible. Thanks to that gentleman, objects on different planes may be readily and exactly reproduced on a single plane. Here is the description of this useful con¬ trivance: A frame of wood ABCD, through which, from the side AB, a plate of glass can be passed, filling the space of the sash abed. The frame is fixed upon some support and held in a perfectly horizontal position, which is gauged by a water- level nn' placed at the base of the frame. At the point E is a small ruler, movable about a hinge at E, and whose angle with the plane of ABCD can be made to vary by resting it on two supports ee', themselves movable about an axis fixed upon the little ruler. At the extrem¬ ity E' of the ruler is fastened a copper blade, bent in the direction E'C', and pierced by a hole FUN WITH MAGIC 114 about 1-10 of an inch in diameter. The edges of the blade are made smaller, as indicated in Fig. 83. the cross-section above in the accompanying illustration. Such is the main part of the apparatus; now for the accessories. The plate of glass which is to be placed in the frame should be submitted FUN WITH MAGIC US to a preparatory process. Choose a plate of the desired size, which will vary according to the dimensions of the design to be drawn, letting the glass be as free as possible from defects, and coat it over on one side with spirits of turpen¬ tine, which is a natural polish. Make the coat¬ ing of polish as thin as practicable by washing the glass with a very supple brush dipped in the turpentine. When you see that the polish does not run and clings to the surface, lay aside your brush and set the glass to dry, for two days if necessary, taking care not to expose it to dust. The instrument is now ready for use. Place it before the object to be drawn, establish the horizontal position of the frame, slip in the glass and so arrange the little rule that through the small hole O you can see the object in question as you wish to have it. Then with your crayon trace the outlines of the object upon the glass, whose polished surface will render it sensitive to the touch of the crayon. It is ob¬ vious that you will have perfectly accurate out¬ lines if you can draw the object exactly as you see it; but the principal purpose of the apparatus is not to obtain exactness of contour, but rather a correct presentation of the different sizes of ii6 FUN WITH MAGIC objects placed on different planes. This can be understood by the aid of the cut. Let AB be an object situated at a certain distance from the eye, which is at o, the visual THE PERSPECTOGRAPH FUN WITH MAGIC ii7 rays OAOB striking the apparatus at a and b, and the image of that object being represented by the line ab. Now, suppose that an object A'B' to be situ¬ ated beyond AB; the eye has not changed its place and its position cannot vary with reference to the glass because the little ruler is fixed. The image of the object A'B' will be at a'b', giving you the true dimensions of A'B' with respect to AB, precisely the proportion which ought to exist between the sizes of ob¬ jects lying in different planes and termed “per¬ spective." The apparatus is therefore properly named the perspectograph. You will see that by means of this little in¬ strument two difficulties are obviated: (1) that of the exactness of the design, which becomes a perfect copy of things as they appear to the eye, and (2) that of perspective. Your picture may be transferred from the glass upon which you have drawn it to paper; you need only raise the small ruler, being care¬ ful not to bend it in doing so, place a sheet of oiled paper on the glass and trace the outlines. Then you can glue the paper to a card, and, if you are anything of an artist, finish your draw¬ ing with taste in regard to shading and similar n8 FUN WITH MAGIC points; for the apparatus does not impart an artistic touch to a picture, but merely accuracy and correct perspective. You can transfer the design, if you wish, a second time, if you prefer not to retain it on the oiled paper; for if you have an accurate picture of an object it is a simple matter for any one with practice in drawing to reproduce it in free-hand. The plate of glass may be used a second time if you will wash it in cold water and let it dry, then recoat it with the varnish. ASCERTAINING THE HEIGHT OF AN EDIFICE OR A MOUNTAIN. The height of an edifice or of a mountain may be computed without any instruments, the only condition necessary being the power to ap¬ proach the base. A foot-rule and two sticks will suffice. Suppose the height of the tower EF be the distance to be taken. At some distance from the base we plant a rod AB about a yard high; and about a yard away we place another stick, somewhat higher, CD. We must now measure the distance BF. Applying the eye to A, we will look to the sum- FUN WITH MAGIC 119 mit of the tower E. Upon the stick CD we will mark the spot where our visual ray cuts this stick, G representing that point. Then by meas- ASCERTAINING THE HEIGHT OF AN EDIFICE OR A MOUNTAIN. uring the distance DG and subtracting the height of AB we shall have GI. We can now conclude the problem with ease with the fol¬ lowing proportion: AH : AI :: EH : GI. A PRACTICAL WAY OF FINDING A MERIDIAN. A meridian of a place means the imaginary line passing through that place and through 120 FUN WITH MAGIC the center of the sun when the latter has ar¬ rived at the arc of the circle which it describes A PRACTICAL WAY OF FINDING A MERIDIAN. daily; at that moment it is midday for the place in question. Since the position of the earth changes every day, the sun does not reach the meridian each day exactly at noon; sometimes it is in advance and sometimes it is late. Many apparatuses have been constructed with the purpose of presenting a practical manner of FUN WITH MAGIC 121 indicating' the meridian of a place. We owe the following method to M. E. Brunner. Upon the sill of a window exposed to the noontide sun fasten securely a little cup filled with mercury. Cover it with a small sheet of varnished metal pierced in the center by a tiny round opening about half an inch in diameter. The lid should be indented so that it can be readily lowered to the surface of the liquid. The window open, the solar ray reflected by the bath of mercury will be projected upon the ceiling of the room. When it is real noon the center of the mirror and the center of the re¬ flected image are in the plane of the meridian. It only remains to make your drawing. At the moment of the passage, note at B, for example, a point corresponding to the center of the image; drive a tack there, and with a string connect the point B with another point out¬ side the window in such a way that the string will pass through the center of the diaphragm M. The line BM is in the plane of the meridian. At A stretch a plumb line which will meet the line BM. Now join upon the ceiling the two points AB and continue as far as D. Draw a heavy line or stretch a dark thread across. The meridian is established. 122 FUN WITH MAGIC In order to ascertain the average hour, you need simply to note the exact moment of pas¬ sage and to deduct the daily corrections which appear in almanacs and in the reports of the Weather Bureau. A FILTER. In this century of microbes it will scarcely be disagreeable to read of a plan for constructing a simple filter for water. Procure a strong wooden box and divide it into three compartments, A, B, C, as indicated in the cut. In compartment A first place a layer of large pebbles, which will diminish in size as they approach the top, finishing with a layer of fine sand; above lay a stratum of char¬ coal H, pounded into large pieces several inches in thickness, then a layer of fine sand, and finally some small pebbles. The filter proper is now made. You will have to be careful that the gravel and sand are carefully washed and that the charcoal is of a good quality, perfectly dry and free from dust. At F and K are two fau¬ cets, the one for clearing the filter and the other for drawing the filtered water. To filter the water place it in the compart- FUN WITH MAGIC 123 ment A, where it will traverse the different lay¬ ers and then flood to> B through an opening L extending across the entire width of the bot- A FILTER. tom and about five inches in height. The com¬ partment B contains only some fine sand, while C is reserved for the filtered water. The faucet at K, which is intended for drawing the water, should be at a few inches distance from the 124 FUN WITH MAGIC base of the filter so that if the filtration has not been perfect any grains of sand which may have been brought along will remain at the bottom. AN ACCURATE PAIR OF SCALES. It seems almost impossible to construct an accurate pair of scales with simply rudimentary materials, but in reality nothing is easier. A scholar’s rule, a tin box (a blacking-box, for example), three little blocks of wood, some twine, four tacks, two pins, a bit of glass and another of cardboard, and you have all the necessary materials; and now for the construc¬ tion. Hollow out the central portion of the rule and upon a single transverse line sink two nee¬ dles, letting them pass slightly beyond through the other side. At one of the ends of the rule C nail one bit of your wood, and at the place where the hook sustaining the plate will come make a slight indenture with a tack so that your hook will not wander over the plate. At the other end, A, fasten a large plate, which shall hold your weights; at the end, in the direction of the length of the rule, solder a pin, the point outside. Your second plate B, designed to re- FUN WITH MAGIC AN ACCURATE PAIR OF SCALES. 126 FUN WITH MAGIC ceive the objects to be weighed, will consist of the lid of the blacking-box. Upon the brim, at equal distances apart pierce four holes, through which you will pass the twine for suspending the plate, and which you will unite above into one, attaching it to a pin that has been trans¬ formed into a hook, or to a fishhook. It now remains to construct the fulcrum for your scales. Upon a rather thick block of wood E fix another block G, to which you will glue a bit of glass with gum arabic. At the socket you will stick four tacks for the purpose of prevent¬ ing the beam from going either to the right or to the left. The little truncated pyramid D shown in the cut illustrates what it should be. In using the scales suppose that you place in the plate A a weight which you judge to be slightly heavier than the substance which is to be weighed. Then, the plate being filled, you will seek to obtain an equilibrium by bringing the weight of A more or less near the ruler; you will notice the division indicated by the point, then you will remove from B what you had placed in it, and you will now need only to place in that plate the weights as far as the point of the plate A in order to show you that the equilibrium previously taken is re-estab- FUN WITH MAGIC 127 lished. As you see, these scales do not need to be accurate; it suffices that they are sensible. AN ECONOMICAL LETTER-WEIGHT. Take the spring of a watch or of a small clock and fasten it by the middle to a little rod. At AN ECONOMICAL LETTER-WEIGHT. the other end fix a small brass hook, as the ac¬ companying cut shows, and at the top of the hook attach an index which will run the length of a band of cardboard also fastened to the rod. The letter-weight is now constructed; you will graduate your scale, and when this preliminary work is completed you can weigh letters and 128 FUN WITH MAGIC small objects with sufficient accuracy. The spring being of steel, it will always resume its former shape. A PHOTOGRAPHIC CAMERA. Here is a very simple method of making a camera for a pocket photographic apparatus. Cut a square of stout cardboard measuring two or three inches on a side. In the middle make a circular opening a little larger than your lens which you will fit to the aperture, having the rim of the glass touch the outline of the orifice. Then cut out two triangles from the same cardboard, with one side equal to the side of the square, and a length calculated according to the focus of the lens. For a simple lens the length of the triangles should be about one-half the length of its focus. The two triangles being cut out, paste them to the square at A and B; their base C will sup¬ port a rectangular mirror of the same dimen¬ sions as the side C of the square and the side of the triangles. Upon the side D place a piece of rough glass, or, in default of that, some thin, transparent paper, tissue-paper, for example. It will now be necessary to construct a sort FUN. WITH MAGIC 129 of parasol designed to conceal the sunbeams which would destroy the image upon the glass. Fig. 93. Fig. 94. 130 FUN WITH MAGIC Cut out a piece of cardboard which is abso¬ lutely opaque into the shape indicated in the A PHOTOGRAPHIC CAMERA. figure; the dotted lines show where it is to be FUN WITH MAGIC 131 turned under. You will attach the parasol to the camera by passing through the holes SS an iron shank or needle, which will also pene¬ trate the upper angle of the triangles forming the sides. You will now have only to fasten your lens to the orifice in the square and your camera is finished. The parasol is used to make the darkness as complete as possible so that the operator can perceive in the middle of the camera the object or the person which he wishes to photograph. AN ECONOMICAL PLATE HOLDER. Six objects very readily to be had while at table are requisite in order to construct the economical plate-holder: three knives and three glasses of the same height. Invert the glasses and arrange them in the form of a triangle, placing upon each the handle of one of the knives. You will cross the blades in such a way that the first one put in position will pass over the second, and the second will pass over the third, the last passing over the first; the blades will then sustain each other in a mutual support, and you can place upon them a dish or any other heavy object without run- 132 FUN WITH MAGIC ning any risk of having the holder give way. The disposition of the glasses and knives is suf- AN ECONOMICAL PLATE HOLDER. ficiently clearly indicated in our design to make detailed explanations needless. THE TACK IN THE CEILING. To insert a tack into the ceiling without a hammer and without the aid of a step-ladder to reach the ceiling, appears to be a wholly im¬ practicable feat, yet with a little dexterity noth¬ ing is simpler. Take a carpet or an artist’s tack and set it on its head upon a penny; then place over it a FUN WITH MAGIC 133 sheet of thin paper, allowing the point of the tack to pierce through. Now fold the paper underneath the penny as indicated in the cut, THE TACK IN THE CEILING. and, this done, seize the coin in your hand and toss it violently to the ceiling, being careful that in its passage it will keep in place. It will reach the ceiling very rapidly, the tack will adhere, and the violence of the shock will tear the paper, which, loaded with the penny, will sink to the floor. Supposing that you have a light object to sus¬ pend to the ceiling; you can do so by attach- 134 FUN WITH MAGIC ing it to the tack and proceeding as just indi¬ cated. If the packet will be cleverly hurled the tack will sink well into the ceiling and take a secure hold. TO CUT A ROPE WITH THE HANDS. The following instructions will enable you to TO CUT A ROPE WITH THE HANDS. sever a cord of very respectable thickness, re FUN WITH MAGIC 135 quiring only a little deftness and a brisk move¬ ment. Fasten the cord about your hand so as to form a loop as shown in the illustration, the end pass¬ ing three or four times around your fingers so as to insure solidity to the loop; this done, take the end in the other hand, give it three or four turns about your hand, then draw it with a sharp jerk; the string will break neatly at the juncture of the loop in the left hand. When you become practiced you will be able to sever the string with two thumbs alone. A DRAWING GLASS. Upon one of the surfaces of a piece of glass lay a coat of lampblack diluted in rich oil. If you will place your glass thus prepared upon an engraving representing flowers, fruits, birds and the like you will perceive an infinite variety of forms, some of which will be absolutely- charming. In order to reproduce these in per¬ manent form it will suffice to interpose a sheet of transparent paper, vegetable or otherwise, to draw a stroke of your crayon the length of the glass, and to outline that part of the design which ends at the foot of the glass. Then fold 136 FUN WITH MAGIC the paper along the line you drew and you can then finish the design. A DRAWING GLASS. The glass, fulfilling the office of mirror, doubles the figures in symmetrical forms, and according as one makes it move it creates new shapes. FUN WITH MAGIC 137 AN ARCHERY WITH PENS. To make a bow of whalebone and to outline a target with two or three concentric circles AN ARCHERY WITH PENS. does not offer many difficulties. For arrows take a steel pen and divide it into two parts; fix each part to a match and you have an en- 138 FUN WITH MAGIC tertaining and inoffensive little archery in your own room. A SIMPLE AND ECONOMICAL MULTI- PLIGRAPH. Steep two sheets of blotting paper in an ani¬ line ink and place one above the other. Write in very delicate characters upon a card whatever you wish to reproduce, and then prick with a pin the words which you have traced. The holes should be extremely neat and close together. Apply this card on the side you have written upon to the sheets of blotting paper im¬ pregnated with ink and press upon it vigorously so that the words traced will be reproduced upon your paper in dots. If your pin-holes have been well made you can in this way draw a num¬ ber of proofs. You can fasten the blotting paper and the type-card to a small board with artist’s tacks. THE MAGIC THEATER. It is necessary for a complete illusion that you draw on cardboard and cut out the facade of a theater. The success of this feature of your FUN WITH MAGIC 139 toy will depend upon your skill as an artist. Behind the curtain place upon a little alcohol lamp a saucepan whose interior is carefully oiled. THE MAGIC THEATER. Throw into it some bits of rubber cut into very fine pieces. When the rubber begins to melt toss a spoonful of cold water briskly into the saucepan, when numbers of sparks will instantly form, dancing in all directions and resembling a bouquet of artificial flowers. 140 FUN WITH MAGIC THE HERMETICAL CORK. How often it happens that a bottle is to be corked, and the only corks at hand are too large THE HERMETICAL CORK. for its neck! The usual thing done in that case is to cut down a cork, with the result that it fits the orifice in question but very imperfectly. A better plan under the circumstances would be an arrangement such as is indicated in the illustration: four slits in the cork. Thus pre- FUN WITH MAGIC 141 pared, it will seal hermetically any phials or bot¬ tles. AN ECONOMICAL BINDING FOR PAPERS. Do not throw away your old envelopes, but preserve them for making an economical bind¬ ing for papers and tracts. Cut the envelopes as indicated in the first Fig. 105. figure, that is to say, upon its two lateral sides, so that you can open it as shown in the second illustration. This done, you can turn it over and FUN WITH MAGIC LA 3CIENCT MOO£Rlvr , cA S' . ./y < . . AN ECONOMICAL BINDING FOR PAPERS. glue the paper below. You will then have solid and inexpensive binding. FUN WITH MAGIC 143 RAPID VEGETATION. A cheap sponge suffices for the foundation of a hanging-basket. Plunge it into- hot water 144 FUN WITH MAGIC and then press it so as to drain it of one-half of the liquid; then, in the holes, the pores of the sponge, introduce grains of millet, of red clover, of barley, of flax, of gramineal and the like, any plants, in fact, which germinate readily and which all together will present as large a variety as possible in the tinting of their leaves. The sponge being thus prepared, place it upon a vase, or, better, suspend it in a window where the sun shines part of the day. Every morning for a week water its entire surface with a gentle sprinkling of water. Soon the seeds will begin to germinate and then to sprout, and in a very brief period of time you will have a ball of ver¬ dure which will serve as an adornment to* a room. THE AUTOMATIC PEDESTRIENNE. The walking doll, which is a common object in toy shops, is constructed on very simple and practical principles of mechanics. The doll con¬ sists of a metal puppet, through whose hands passes a steel wire curved in the form of an in¬ verted V, as indicated in our design. By means of this contrivance it maintains an upright posi¬ tion, leaning on the wire for support. The doll FUN WITH MAGIC is placed on an inclined plane, a small board resting on two slender metal columns, that at 146 FUN WITH MAGIC one end being higher than that at the other, thus affording the desired slope. The puppet advances, bearing first upon one leg and then upon the other, precisely imitating the motions of a person when walking. This result is ob¬ tained without any but the simplest mechanism. The start is made at the top of the plane by giving the doll a light stroke on her side. This blow, augmented by the wire upon which she rests, causes her to lean first to one side and then to the other. Now, when she leans to the left all the weight of her body is brought to bear upon her left leg, while the right leg, being free of all burden, is naturally carried forward upon the board. The oscillation continues and the weight is now transferred to the right foot, the left goes ahead in its turn, and so on. The little pedestrienne presents a very inter¬ esting spectacle, which, to those ignorant of the secret of her apparent locomotion, appears to be the result of a complicated piece of machin¬ ery. THE HORSEWOMAN. This toy is one of the most curious of its kind. FUN WITH MAGIC 147 Picture to yourself a heavy pivot whose axis THE HORSEWOMAN. is provided with a socket which - can revolve 148 FUN WITH MAGIC freely. This socket, by means of two arms, sus¬ tains a heavy top, which constitutes a fly-wheel, its lower extremity touching upon the inclined surface of the socket. The other extremity of the axis of the top is surmounted by a toy wheel, about which is twined the cord destined to set the top in motion. Such is the motive power of the equestrienne. The horse is connected with the socket by a horizontal wire, around which it can oscillate. Between its hind feet is fastened a small eccen¬ tric wheel, which imparts to the little animal a series of vaulting movements resembling a horse galloping. By means of another cord the equestrienne is united to the socket. This wire fits into a vertically situated disk, about which it twines, and ends in a loop, forming a button which rests on the floor. The horsewoman’s feet serve to hold the wire against a cog, which revolves about the central axis of the pivot. The vertical disk which supports her can oscillate about its axis. The cog bears a spur which is located slightly in front of the obstacle over which the puppet must leap. The top having been set in motion, it is car¬ ried by friction around the socket and commu¬ nicates its movement to the central socket, FUN WITH MAGIC 149 which in its turn involves the equestrienne in motion. The end resting upon the cog will come in contact with the spur, which causes the wire sustaining the puppet to straighten out, when the latter will briskly leap over the obstacle and descend upon her horse. The in¬ telligence of the inventor has been particularly exercised in the secondary movements. He has given the cog a very feeble spoke; it follows that the moment the doll gets in position to leap she inclines slightly forward as if she were about to take a leap. The little horse not only re¬ volves, but, thanks to the small eccentric wheel of which mention has been made, he goes through a series of motions very similar to those of steeds at full gallop. The engraving presents a view of the entire toy, which is a marvel of ingenuity. THE MECHANICAL ELEPHANT. The mechanical elephant derives his power of locomotion from the strength of a fly-wheel animated by a very lively angular movement. This fly-wheel consists of the parasol which sur¬ mounts the head of the driver, doing its work by means of a string. Its axis, which is almost 150 FUN WITH MAGIC vertical, just touches the circumference of a iiililR LrUmI 1 ;:’TO«l!!!!!]l!;!!|§||j! ... . ( |> ... . ;gS»» - -... tiiMKHHiHu.ui.iinniinKi|iii;i;i" l| !uiiiii ,, i":r;;-; l .;:U » «wS S&B8BHHR «i SiitainaSiffi “CfleS?" MiieuJi vsm&ap •jisrissP* jMIfflWIHWjii; jill! i!ii!| ••iijlj;!! ? ‘1 III Pi MH IK mm ^ NHW mm\ I: 1 !;: j-iKij' THE MECHANICAL ELEPHANT. slightly conical wheel whose axis is horizontal FUN WITH MAGIC I 5 i Upon this axis are two handles which reunite, Fig. 112. one from each side, two cranks connecting the 152 FUN WITH MAGIC legs of the elephant and imparting to them an alternating movement. The handles are dis¬ posed in such a way that the two legs on one side oscillate in an inverse direction and in op¬ position to the two others. In order to arrange that each foot will rest immobile upon the ground during the move¬ ment forward, the inventor has placed a tiny brake in each leg, provided with a small mar¬ ble. When the forward movement takes place the brake turns upon the floor; in the contrary case the marble goes between the interior wall of the leg and the brake and prevents the latter from turning. The gait of the animal is absolutely regular. The legs move slowly along, alternating be¬ tween the left and the right and keeping the entire apparatus in perfect equilibrium so that the ponderous march of the powerful pachy¬ derm is cleverly imitated. THE SOMERSAULT. f ' Another toy which again is a marvel in its simplicity. Based upon principles similar to those of the toys previously described, the somersault is FUN WI TH MAGIC 153 THE SOMERSAULT, FUN WITH MAGIC 154 composed of a socket carrying a horizontal wheel whose circumference is slightly softened. The axis, with the aid of arms, supports a heavy disk whose axis, placed horizontally, bears on one side upon a vertical wheel and on the other is terminated by a little bobbin wound round with rubber. The axis of the vertical wheel is prolonged and supports at its extremity two tiny puppets representing two children whose bodies can bend in two. This little contrivance will be set in motion if you will strike the little bobbin with a small stick mounted in a handle. Make your blow sharp, drawing the stick toward you, and the bobbin, which is located upon the same axis with the disk, will give to the latter a rapid movement of rotation. This movement will be communicated to the vertical wheel by means of the other extremity of the axis, which is ter¬ minated by an endless screw; the vertical wheel is then caught between two frictions; it sets the two puppets in motion, causing them to leap the one over the other. The arm which sup¬ ports them enters below the shoulder and the opening is longitudinal, enabling the support to glide downward in the opening. It follows that FUN WITH MAGIC 155 the puppet, when touching the ground, will lower itself slightly, thus producing a perfect imitation of the schoolboy as he bends down so that his comrade may spring over him. THE BOXERS. Our chapter of marvels in ingenuity con¬ cludes with a most curious toy—a pair of boxers who engage in a veritable match. The mech¬ anism, as in the other toys, is of the simplest. A horizontal rod portrayed at the base of the drawing serves as a balancing-beam. It is con¬ nected with an arm by an axis which supports a muff. The movement is given by a strong elastic, which is twisted by means of an ex¬ terior handle. This elastic, in loosening, causes a toothed wheel to revolve, which works in with the muff. One foot of each boxer is fixed upon a vertical axis bent into Z shape; the two axes are united by a crank, which makes them execute the same movements. One of the axes has an arm pro¬ longed to the end of the horizontal balancing- beam, so that each time the toothed wheel turns a movement in and out is inaugurated, which is communicated to the two boxers. Since but 156 FUN WITH MAGIC one of the feet of each is held fixed and the other THE BOXERS. three members, thanks to the rubber, are ren¬ dered free and mobile, it follows that every FUN WITH MAGIC 157 movement of the machinery below impels them to execute a series of interesting gestures ex¬ ceedingly appropriate to the scene represented by the toy. THE TOP SPOUTING WATER. Here is a curious application of a gyratory motion in a liquid medium. The instrument which will serve to throw a jet of water in a room, and, better still, to pre¬ sent an imitation of a fountain, is a simple top, very heavy and with its axis traversed by a slen¬ der conduit with an interior furrow terminating the lower part of the axis. In order to arrive at the desired result you need only to impart a strong rotary movement to the top by means of a twine twisted about it in the direction indicated by the arrow in the cut and to place it in a plate of water whose level rises about to the middle of the furrow. By means of an independent foot provided with a bit of cloth so as to preserve adhesion to the bottom of the plate the top will remain upright and revolve upon that foot. The movement of the furrow will create an ascending eddy, which will penetrate into the axis of the top, and a jet THE TOP SPOUTING WATER. FUN WITH MAGIC 159 of water will emerge, rising as much as a yard high. With the use of some colored liquid, red or blue ink, for example, and with some experi¬ mentation with the effects at night under arti¬ ficial light, you can obtain a copy in miniature of a luminous fountain. A TRICK AFTER ROBERT HOUDIN. This recreation cannot at first appear to have a scientific character, but rests almost entirely upon an optical illusion, so that even after you have executed it before a number of persons you can still state that you find it impossible to explain the feat. Have your two wrists tied together with some bandage, preferably a silk handkerchief, the palms of your hands placed against each other, your fingers stretched out. Then ask some one to pass between the two wrists, underneath the handkerchief, a strong little cord without any knots, at least 4 or 5 yards long. You will then have some person grasp the two extremities of the cord and you will request him to draw it hard towards himself. Thus equipped, you will announce that, without cutting the cord, with- i6o FUN WITH MAGIC out having the extremities loosened, and re¬ maining with your wrists bound, you will dis¬ entangle the string. Every one will declare that it cannot be done. Your end will be realized if you will bend back one of your hands underneath and with the mid- A TRICK AFTER ROBERT HOUDIN die finger seize the loop of the cord, which still remains stretched, as will be seen in the cut. Then take a few steps forward so as to loosen the cord and pass the loop beneath your fingers. You will now request the person holding the ends of the cord to pull it toward him again, and it will at once emerge from your hands alone. In reality the loop had slipped between the handkerchief and the palm of your hand. FUN WITH MAGIC 161 As a preventive against any one perceiving the movements of your fingers, it will be best for you, during the operation, to agitate your hands briskly in all directions so that the specta¬ tors cannot see what you are doing. POPULAR FIRE-WORKS. As your materials, take simply an ordinary box of Swedish matches. Remove one match POPULAR FIRE-WORKS. and take the position indicated in the illustra¬ tion, that is to say, hold the box in a slightly FUN WITH MAGIC 162 slanting posture between the thumb and the index finger, and place the match with its head against the side to be scratched. Bear with moderate force upon the match, and with your free hand strike it sharply at A in the direction indicated by the arrow. You will see the wooden end spinning and burning the while, and finally falling at a distance of from 3 to 6 yards. After a little practice you can meet with suc¬ cess at every trial. The experiment is very pretty, particularly at night in complete dark¬ ness, when it has the very appearance of minia¬ ture rockets. A TARGET LINE. Here is an exceedingly interesting amuse¬ ment and very easy of success, although it may at first appear somewhat difficult. Invert a glass and by means of a soft crumb of bread stand a match in an upright position on its top. Upon the edge of the table place an¬ other match, resting one end of it on some sup¬ port, a bit of cork or the like. Then lean down and look at the vertical match upon the glass in such a way that the other on the table will FUN WITH MAGIC 163 be exactly on a line with it. This ascertained, rap A TARGET LINE. upon the lower extremity of the second match and it will strike the match on the glass. THE ENCHANTED COIN. If you succeed in performing the following trick you may be assured of success as a con¬ jurer. Provide yourself as utensils with a drinking- glass having flat bottom and on pedestal if pos¬ sible; with a pocket-handkerchief, with a coin, 164 FUN WITH MAGIC and, in secret, with a watch-glass or a large glass counter. Now let every one present see you place the THE ENCHANTED COIN. coin in the center of the handkerchief and fold the latter about it, stating at the end that the coin is still in its place. As a verification of your words, ask some one to feel of the handkerchief for the coin. Then hold all over a glass con¬ taining a little water, loosen the handkerchief FUN WITH MAGIC 165 and the sound of the piece of money as it touches the bottom of the glass will be heard. Raise your handkerchief, unfolding it in full view. There will be nothing in the tumbler! The ex¬ planation is simple. All your skill must be con¬ centrated in adroitly substituting the watch- glass for the coin at the time that the latter is supposed to be placed in the center of the hand¬ kerchief. In falling the glass will produce the same sound as a piece of money. A DIMINUTIVE CATAPULT. Take a box of Swedish matches and stand it on end. Then slip two matches between the walls of the box, one on each side, with the phosphorated ends above and the other ends firmly inserted below. Place a third match hori¬ zontally between them as a cross-beam, keep¬ ing it in position by the pressure which they exert in the effort to resume the vertical position from which is has displaced them. You must be very careful that the cross-beam is somewhat longer than the distance separating the upright matches. Now light the middle match and wait. When the fire has sufficiently diminished its size and FUN WITH MAGIC 166 force of resistance, a moment will come when the vertical matches will be able to assume their A DIMINUTIVE CATAPULT. former position, in doing which they will pro¬ ject it into space. They will then stand erect as at first, unharmed by the flame. THE FOUR MATCHES. Take two matches, make a notch in each at the unphosphorated end, and fit the one into the FUN WITH MAGIC 167 THE FOUR MATCHES FUN WITH MAGIC 168 other so as to form an angle. Now place them vertically upon a table, using a third match as a support, something after the fashion of an easel. Then with your fourth match raise the other three without disturbing the little erec¬ tion and transport it to some other place. Ap j parently a difficult feat, this may very readily be done. It will suffice if you slip the fourth match between the two held together by theif extremities and the supporting match. If you will press it lightly against the first two matches the third match will change its position, placing its upper end between the angle formed by the two others. Lift the whole briskly and this end will be firm and you can remove the easel to some other spot. HOW TO RAISE FOUR KNIVES WITH ONE KNIFE. Here is an interesting little trick in balancing. Detailed explanations are scarcely necessary, since the figure illustrates with sufficient clear¬ ness the manner of procedure. First lay a knife on a table directly in front of you, then two other knives, which will be placed blade upon blade above the first; now the two remaining FUN WITH MAGIC 169 knives should be transversely arranged, their blades passing over the blades of the two just HOW TO RAISE FOUR KNIVES WITH ONE KNIFE. located and beneath the blade of the first knife. In lifting the handle of the latter you will then be enabled to raise the whole without breaking the equilibrium. THE VAULTING PEA. Take a straw 4 or 5 inches long and about one-fifth of an inch in diameter, unbroken and a perfect tube. Divide one of its ends for a distance of per¬ haps three-quarters of an inch into 4 or 5 sec¬ tions, which you will lightly separate so as to form a truncated cone. 170 FUN WITH MAGIC The straw thus prepared, place a green pea of about the same diameter as the straw into THE VAULTING PEA. the cone, hold the straw perpendicularly and breathe forcibly into the other end. The pea will immediately be projected into the air by the column of air which you intro¬ duced into the tube, and will there remain so long as the propulsion will last, when it will sink back among the branches of the cone. This experiment may be varied by passing a pin FUN WITH MAGIC 171 through the pea, allowing its point to reach into the straw. If the pea will be well shot, it will keep up at a distance of three or four inches from the orifice of the tube, rising or sinking according to the greater or less strength of the propulsion. A PROBLEM IN CHECKERS. Arrange eight men so that there will be but A PROBLEM IN CHECKERS. one man on each line, whether horizontal, per¬ pendicular or diagonal. 172 FUN WITH MAGIC The first man should be placed upon the third square from the top; the second upon the sixth square from the bottom; 3 and 6 are 9. The third man goes on the fifth square of the second vertical row, and the fourth upon the fourth square of the last but one row; 5 and 4 also are 9. The fifth man goes upon the second square of the third row, and the sixth upon the sixth row in the seventh square; 2 and 7 are 9. Finally the seventh man is placed upon the eighth square of the fourth row, and the eighth man upon the first square of the row below; 8 and 1 are 9. SHADOW-PICTURES. These are very simple recreations which serve as pleasant evening pastimes. If you possess a certain suppleness of hand, you can make the pictures by arranging your fingers as indicated in the accompanying illustrations. If not, you can cut them out of cardboard and so obtain the same results, with this exception, that those made with the living hand have the advantage of being able to represent the movements of the objects delineated. With a little practice, FUN WITH MAGIC 173 SHADOW-PICTURES. 174 FUN WITH MAGIC SHADOW PICTURES. FUN WITH MAGIC 175 any one can attain a certain skill in depicting the subjects with their hands, and will also be able to compose other subjects; for the field is vast. Only the simplest and most easy of exe¬ cution are herewith presented.