To Show The Pressure Of The Atmosphere
Invert a tall glass or jar in a dish of water, and place a lighted
taper under it: as the taper consumes the air in the jar its pressure
becomes less on the water immediately under the jar; while the
pressure of the atmosphere on the water without the circle of the
jar remaining the same, part of the water in the dish will be forced
up into the jar, to supply the place of the air which the taper has
consumed. Nothing but the pressure of the atmosphere could thus cause
part of the water to rise within the jar, above its own level.
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To Observe An Eclipse Of The Sun Without Injury To The Eye
Take a burning-glass, or spectacle-glass, that magnifies very much; hold it before a book or pasteboard, twice the distance of its focus, and you will see the round body of the sun, and the manner in which the moon passes between the glass and the s... To Prepare Charcoal For Fire-works
Charcoal is a preservative, by which the saltpetre and brimstone are made into gunpowder, by preventing the sulphur from suffocating the strong and windy exhalation of the nitre. There are several sorts of wood made use of for this purpose; some pre... To Procure Hydrogen Gas
Provide a phial with a cork stopper, through which is thrust a piece of tobacco-pipe. Into the phial put a few pieces of zinc, or small iron nails; on this pour a mixture, of equal parts of sulphuric acid (oil of vitriol) and water, previously mixed... To Produce Beautiful Fire-works In Miniature
Put half a drachm of solid phosphorus into a large pint Florence flask; holding it slanting, that the phosphorus may not break the glass. Pour upon it a gill and a half of water, and place the whole over a tea-kettle lamp, or any common tin lamp, fi... To Produce Fire By The Mixture Of Two Cold Liquids
Take half a pound of pure dry nitrate, in powder; put it into a retort that is quite dry; add an equal quantity of highly rectified oil of vitriol, and, distilling the mixture in a moderate sand heat, it will produce a liquor like a yellowish fume; ... To Produce Fire From Cane
The Chinese rattans, which are used, when split, for making cane chairs, will, when dry, if struck against each other, give fire; and are used accordingly in some places, in lieu of flint and steel. ... To Produce Metallic Lead From The Powder
Take one ounce of red lead, and half a drachm of charcoal in powder, incorporate them well in a mortar, and then fill the bowl of a tobacco-pipe with the mixture. Submit it to an intense heat, in a common fire, and when melted, pour it out upon a sl... To Produce The Appearance Of A Flower From Its Ashes
Make a tin box, with a cover that takes off. Let this box be supported by a pedestal of the same metal, and on which there is a little door. In the front of this box is to be a glass. In a groove, at a small distance from this glass, place a doubl... To Produce The Appearance Of A Spectre On A Pedestal In The Middle Of
a Table. Enclose a small magic lantern in a box, Fig. 11, large enough to contain a small swing dressing-glass, which will reflect the light thrown on it by the lantern in such a way, that it will pass out at the aperture made at the top of the box... To Pulverize Saltpetre
Take a copper kettle, the bottom being spherical, and put into it fourteen pounds of refined saltpetre, with two quarts or five pints of clean water; then put the kettle on a slow fire, and when the saltpetre is dissolved, if any impurities arise, s... To Remove Stains And Blemishes From Prints
Paste a piece of paper to a very smooth clear table, that the boiling water used in the operation may not require a colour which might lessen its success. Spread out the print you wish to clean upon the table, and sprinkle it with boiling water; tak... To Represent A Storm At Sea
Provide two strips of glass, whose frames are thin enough to admit both strips freely into the groove of the lantern. On one of these glasses paint the appearance of the sea from a smooth calm to a violent storm. Let these representations run gradua... To Represent Cascades Of Fire
In cutting out cascades, you must take care to preserve a natural inequality in the parts cut out; for if, to save time, you should make all the holes with the same pointed tool, the uniformity of the parts will not fail to produce a disagreeable ef... To Separate The Two Colours Of A Pack Of Cards By One Cut
To perform this amusement, all the cards of one colour must be cut something narrower at one end than the other. You show the cards, and give them to any one, that he may shuffle them; then holding them between your hands, one hand being at each ext... To Set Fire To A Combustible Body By Reflection
Place two concave mirrors at about twelve 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 some gunpowder. With a pair of strong bellows keep bl... To Show That The White Of Eggs Contains An Alkali
Add to a wine-glass half full of tincture of red cabbage a small quantity of the white of an egg, either in a liquid state or rendered concrete by boiling. The tincture will lose its blue colour and become changed to green, because the white of the ... To Show The Pressure Of The Atmosphere
Invert a tall glass or jar in a dish of water, and place a lighted taper under it: as the taper consumes the air in the jar its pressure becomes less on the water immediately under the jar; while the pressure of the atmosphere on the water without t... To Show The Spots In The Sun's Disk By Its Image In The Camera
Obscura. Put the object-glass of a ten or twelve feet telescope into the scioptric ball, and turn it about till it be directly opposite the sun. Then place the pasteboard mentioned in page 16, in the focus of the lens, and you will see a clear brig... To So Fill A Glass With Water That It Cannot Be Removed Without
spilling the whole. This is a mere trick, but may afford some amusement. You offer to bet any person that you will so fill a glass with water that he shall not move it off the table without spilling the whole contents. You then fill the glass, and,... To Soften Horn
To one pound of wood-ashes, add two pounds of quick lime; put them into a quart of water. Let the whole boil till reduced to one-third. Then dip a feather in, and if, on drawing it out, the plume should come off, it is a proof that it is boiled enou... To Soften Iron Or Steel
Either of the following simple methods will make iron or steel as soft as lead: 1. Anoint it all over with tallow; temper it in a gentle charcoal fire, and let it cool of itself. 2. Take a little clay, cover your iron with it, temper it in a c... To Spin Sealing-wax Into Threads By Electricity
Stick a small piece of sealing-wax on the end of a wire, and set fire to it. Then put an electrical machine in motion, and present the wax just blown out at the distance of some inches from the prime conductor. A number of extremely fine filaments w... To Take A Plaster-of-paris Cast From A Person's Face
The person must lie on his back, and his hair be tied behind. Into each nostril put a conical piece of paper, open at each end to allow of breathing. The face is to be lightly oiled over, and the plaster being properly prepared is to be poured over ... To Take Impressions Of Coins Medals &c
Cut fish-glue, or isinglass, into small pieces, immerse it in clear water, and set it on a slow fire; when gradually dissolved, let it boil slowly, stirring it with a wooden spoon, and taking off the scum. The liquor being sufficiently adhesive, tak... To Tell A Person Any Number He May Privately Fix On
When the person has fixed on a number, bid him double it and add four to that doubling; then multiply the whole by 5; to the product let him add 12, and multiply the amount by 10. From the total of all this, let him deduct 320, and tell you the rema... To Tell Any Number A Person Has Fixed On Without Asking Him Any
Questions. You tell the person to choose any number from 1 to 15; he is to add 1 to that number, and triple the amount. Then, 1. He is to take the half of that triple, and triple that half. 2. To take the half of the last triple, and triple t... To Tell By A Watch Dial The Hour When A Person Intends To Rise
The person is told to set the hand of his watch at any hour he pleases, which hour he tells you; and you add in your mind 12 to it. You then desire him to count privately the number of that addition on the dial, commencing at the next hour to that a... To Tell How Many Cards A Person Takes Out Of A Pack And To Specify
each Card. To perform this, you must so dispose a PIQUET pack of cards, that you can easily remember the order in which they are placed. Suppose, for instance, they are placed according to the words in the following line, Seven Aces, Eight Kin... To Tell The Amount Of The Numbers Of Any Three Cards That A Person
shall draw from the Pack. After the person has drawn his three cards, draw one yourself and lay it aside, for it is necessary that the number of the remaining cards be divisible by three, which they will not be in a pack of fifty-two cards, if only... To Tell The Amount Of The Numbers Of Any Two Cards Drawn From A
common Pack. Each court card in this amusement counts for ten, and the other cards according to the number of their pips. Let the person who draws the cards add as many more cards to each of those he has drawn as will make each of their numbers twe... To Tell The Card That A Person Has Touched With His Finger
This amusement is to be performed by confederacy. You previously agree with your confederate on certain signs, by which he is to denote the suite, and the particular card of each suite; thus: if he touch the first button of his coat, it signifies an... To Tell The Number Of Points On Three Cards Placed Under Three
different Parcels of Cards. You first premise that the ace counts for eleven; the court cards ten each; and the others according to the number of their pips. You then propose to any person in company to choose three cards, and to place over each as...