Invisible Ink
Put litharge of lead into very strong vinegar, and let it stand
twenty-four hours. Strain it off, and let it remain till quite
settled; then put the liquor in a bottle.
You next dissolve orpiment in quick lime water, by setting the water
in the sun for two or three days, turning it five or six times a-day.
Keep the bottle containing this liquor well corked, as the vapour is
highly pernicious if received into the mouth.
Write what you wish with a pen dipped in the first liquor; and, to
make it visible, expose it to the vapour of the second liquor. If you
wish them to disappear again, draw a sponge or pencil, dipped in aqua
fortis, or spirit of nitre, over the paper; and if you wish them to
re-appear, let the paper be quite dry, and then pass the solution of
orpiment over it.
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Glass Broken By Air
Lay a square of glass on the top of an open receiver, and exhaust the air. The weight of the external air will press on the glass, and smash it to atoms. ... Golden Ink
Take some white gum arabic, reduce it to an impalpable powder, in a brass mortar; dissolve it in strong brandy, and add a little common water to render it more liquid. Provide some gold in a shell, which must be detached, in order to reduce it to a ... Gunpowder Exploded By Reflection
Place two concave mirrors at about 12 or 15 feet distance from each other, and let the axis of each be in the same line. In the focus of one of them place a live coal, and in the focus of the other place some gunpowder. With a pair of double bellows... Honorary Rockets These Are The Same As Sky-rockets Except That
they carry no head nor report, but are closed at top, on which is fixed a cone; then on the case, close to the top of the stick, is tied on a two-ounce case, about five or six inches long, filled with a strong charge, and pinched close at both ends; t... Horizontal Water-wheels
To make horizontal wheels for the water, first get a large wooden bowl without a handle; then have an eight-sided wheel, made of a flat board 18 inches diameter, so that the length of each side may nearly be seven inches: in all the sides cut a groo... Horizontal Wheels They Are Best When Their Fells Are Made
circular; in the middle of the top of the nave must be a pintle, turned out of the same piece as the nave, two inches long, and equal in diameter to the bore of one of the cases of the wheel; there must be a hole bored up the centre of the nave, withi... How Far Sound Travels In A Minute
However it may be with regard to the theories of sound, experience has taught us, that it travels at about the rate of 1142 feet in a second, or nearly thirteen miles in a minute. The method of calculating its progress is easily made known: when a g... How To Make The Pass Hold The Pack Of Cards In Your Right Hand So
that the palm of your hand may be under the cards: place the thumb of that hand on one side of the pack; the first, second, and third fingers on the other side, and your little finger between those cards that are to be brought to the top, and the rest... How To Meal Gunpowder Brimstone And Charcoal
There have been many methods used to grind these ingredients to a powder for fire-works, such as large mortars and pestles made of ebony, and other hard woods; but none of these methods have proved so effectual and speedy as the last invention, that... Illuminated Phosphorus
Put some of Canton's phosphorus into a clear glass phial, and stop it with a glass stopper, or a cork and sealing-wax. If this wire be kept in a darkened room (which for this experiment must be very dark) it will give no light; but let two or three ... Illuminated Prospects
Provide yourself with some of those prints that are commonly used in optical machines, printed on very thin white paper; taking care to make choice of such as have the greatest effect from the manner in which the objects are placed in perspective. P... Illuminated Spiral Wheel First Have A Circular Horizontal Wheel
made two feet diameter, with a hole quite through the nave; then take three thin pieces of deal, three feet long each, and three-fourths of an inch broad each: nail one end of each of these pieces to the fell of the wheel, at an equal distance from on... Illuminated Writing
It is well known that if any words are written on a wall with solid phosphorus, the writing will appear as if on fire; but it is necessary to give this caution, lest accidents should occur. In using it, let a cup of water be always near you; and do ... Imitative Fire-works
Take a paper that is blacked on both sides, or instead of black, the paper may be coloured on each side with a deep blue, which will be still better for such as are to be seen through transparent papers. It must be of a proper size for the figure yo... Inflammable Phosphorus
Take the meal of flour of any vegetable, put it into an iron pan over a moderate fire, and keep it stirring with an iron spoon till it changes to a black powder; to one part of this add four parts of raw alum. Make the whole into a fine powder; put ... Interesting Experiment For The Microscope
The embryo grain of wheat, at the time of blossoming, being carefully taken out of the husk, will be found to have a small downy tuft at its extremity, which, when viewed in a microscope, greatly resembles the branches of thorn, spreading archwise, ... Invisible Gold Ink
Put as much gold in as small a quantity of aqua regia as will dissolve it, and dilute it with two or three times the quantity of distilled water. Next dissolve, in a separate vessel, fine pewter in aqua regia, and when it is well impregnated, add... Invisible Green Ink
Dissolve salt of tartar, clean and dry, in a sufficient quantity of river water. Use the violet solution to render it visible. ... Invisible Grey Ink
Mix alum with lemon-juice. The letters written with this ink will be invisible till dipped in water. * * * * * We now present our readers with a variety of amusing experiments, which may be performed by the forego... Invisible Ink
Put litharge of lead into very strong vinegar, and let it stand twenty-four hours. Strain it off, and let it remain till quite settled; then put the liquor in a bottle. You next dissolve orpiment in quick lime water, by setting the water in the s... Invisible Red Ink
To the pure spirit of vitriol or nitre, add eight times as much water. Use the above solution of violets to make visible the characters written with this ink. ... Invisible Silver Ink
Dissolve fine silver in aqua fortis; and after the dissolution, add some distilled water in the same manner as in the gold ink. What is written with the above ink will remain invisible for three or four months, if kept from the air; but may be eas... Invisible Violet Ink
Express the juice of lemons, and keep it in a bottle well corked. Use the violet infusion to make the writing visible. ... Invisible Yellow Ink
Steep marigold flowers seven or eight days in clear distilled vinegar. Press the flowers and strain the liquor, which is to be kept in a bottle well corked. If you would have it still more clear, add, when you use it, some pure water. To make the... Iron Transformed Into Copper
Dissolve blue vitriol in water, till the water is well impregnated with it; and immerse into the solution small plates of iron, or coarse iron filings. These will be attacked and dissolved by the acid of the vitriol, while the copper naturally conta... Iron Transformed Into Silver
Dissolve mercury in marine acid, and dip a piece of iron into it, or rub the solution over the iron, and it will assume a silver appearance. It is scarcely necessary to say, that these transmutations are only apparent, though to the credulous it ... Luminous Liquor
Put a little phosphorus, with essence of cloves, into a bottle, which must be kept closely stopped. Every time the bottle is unclosed, the liquor will appear luminous. This experiment must be performed in the dark. ... Magic Fountain
Take a tall glass tube, hermetically sealed both at top and bottom, by means of a brass cap screwed on to a stop-cock, and place it on the plate of the pump. When the air is exhausted, turn the cock, take the tube off the plate, and plunge it into a... Magical Explosion
Make up some gunpowder, in the form of a small cartridge, in each end of which put a blunt wire, so that the ends inside of the cartridge be about half an inch off each other; then join the chain that proceeds from one side of the electrifying batte... Magical Transmutations
Infuse a few shavings of logwood in common water, and when the liquor is sufficiently red, pour it into a bottle. Then take three drinking-glasses, and rinse one of them with strong vinegar; throw into the second a small quantity of pounded alum, wh... Method Of Rolling Rocket Cases The Cases Must Be Made Of The
strongest cartridge-paper, and rolled dry. The case of a middling-sized rocket will take up paper of four or five sheets thick; having cut your papers to a proper size, and the last sheet with a slope at one end, fold down one end, and lay your former... Method Of Taking The Impression Of Butterflies On Paper
Clip the wings off the butterfly, lay them on clean, in the form of a butterfly when flying. Spread some thick clean gum-water on another piece of paper, press it on the wings, and it will take them up; lay a piece of white paper over it, and rub it... Money Augmented By An Optical Illusion
In a large drinking-glass of a conical shape, (small at the bottom and wide at the top,) put a shilling, and let the glass be half full of water; then place a plate on the top of it, and turn it quickly over, that the water may not escape. You will ... Musical Cascade
Where there is a natural cascade, near the lower stream, but not in it, let there be placed a large wheel, equal to the breadth of the cascade: the diameter of this wheel, for about a foot from each end, must be much less than that of the middle par... Neptune In His Chariot
To represent Neptune in his chariot, you must have a Neptune (made of wood, or basket-work) as big as life, fixed on a float large enough to bear his weight; on which must be two horses' heads and necks, so as to seem swimming. For the wheels of the... Never-yielding Cement
Calcine oyster-shells, pound them, sift them through a silk sieve, and grind them on porphyry till they are reduced to the finest powder. Then take the whites of several eggs, according to the quantity of the powder; and having mixed them with the p... Note All The Vents In The Under Side Of The Cases Must Be Lighted
at once, and the sharp point of the cone cut off; at which place make it spherical. WHEELS. Wheel-cases are made to any length; which must always depend on the size of the wheel, but must not exceed the length of each angle. Charge for wheel... Odoriferous Water-balloons
They are made in the same manner as air-balloons, but very thin of paper, and in diameter one inch and three-fourths, with a vent of half an inch diameter. The shells being made, and quite dry, fill them with any of the following compositions, which...