Bronzing is that process by which figures of plaster-of-paris, wood, &c. are made to have the appearance of copper or brass. The method is as follows: Dissolve copper filings in aq...
By the diagonal position of a plane mirror, a curious opera-glass is constructed, by which any person may be viewed in a theatre or public company without knowing it. It consists o...
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 exper...
Within the case A B C D, place four mirrors O P Q R, Fig. 22, so disposed, that they may each make an angle of 45 degrees, that is, that they may be half-way inclined from the perp...
Charge a small coated phial, whose knob is bent outwards so as to hang a little over the body of the phial; then wrap some loose cotton over the extremity of a long brass pin or wi...
Saturate a certain quantity of water in a moderate heat, with three ounces of sugar; and when it will no longer receive that, there is still room in it for two ounces of salt of ta...
the person deducting ten from twenty-six, there remain sixteen, and deducting seven from twenty-six, there remain nineteen; these two remainders added together make thirty-five, wh...
Opposite a window into which the sun shines direct suspend a glass globe, filled with clean water, by means of a string that runs over a pulley, so that the sun's rays may fall on...
Place a bust on a pedestal in the corner of a room, and let there be two tubes, as in the preceding article, one to go from the mouth, and the other from the ear, through the pedes...
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...
On the bottom of a vessel, lay three pieces of money, the first at A, the second at B, and the third at C, Fig. 3. Then place a person at D, where he can see no farther into the ve...
Take a card, the same as your long card, and, rolling it up very close, put it in an egg, by making a hole as small as possible, and which you are to fill up carefully with white w...
If twenty grains of phosphorus, cut very small, and mixed with forty grains of powder of zinc, be put into four drachms of water, and two drachms of concentrated sulphuric acid be...
Suspend a vessel of water from the middle of the brass arch, and place in the vessel a small tube. The water will be one continued stream; and if the electrification be strong, a n...
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. T...
Two balloons, made of the allantoides of a calf, are to be filled with hydrogen gas, of which each contains about two cubic feet. To each of these is to be suspended, by a silken t...
If we would have an idea of the enormous quantity of water which the sea contains, let us suppose a common and general depth of the ocean; by computing it at only 200 fathoms, or t...
You place a cup of any sort of metal on a stool of baked wood or a cake of wax. Fill it to the brim with any liquor; let it communicate with the branch by a small chain; and when i...
Cover the outside of a small memorandum book with black paper, and in one of its inside covers make a flap, to open secretly, and observe there must be nothing over the flap but th...
Take a small lock of cotton, extended in every direction as much as can conveniently be done, and by a linen thread about five or six inches long, or by a thread drawn out of the s...
Count Morozzo placed successively several full-grown sparrows under a glass receiver, inverted over water. It was filled with atmospheric air, and afterwards with vital air. He fou...
Take the four kings, and behind the last of them place two other cards, so that they may not be seen. Then spread open the four kings to the company, and put the six cards at the b...
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 f...
Form a circle like Fig. 2, divided into twenty-six parts, with a letter of the alphabet written in each. The interior of the circle is moveable, like that in Fig. 1, and the circum...
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 micr...
Pour a little clear water into a small glass tumbler, and put one or two small pieces of phosphoret of lime into it. In a short time, flashes of fire will dart from the surface of...
Make two holes in the wainscot of a room, each a foot high and ten inches wide, and about a foot distant from each other. Let these apertures be about the height of a man's head, a...
Get a ring, made of any metal, in which is set a large transparent stone or piece of glass, to the bottom of which is fastened a small piece of black silk; under the silk is to be...
If you take up a small quantity of melted glass with a tube, (the bowl of a common tobacco-pipe will do,) and let a drop fall into a vessel of water, it will chill and condense wit...
burned. Soak a piece of thread in urine, or common salt and water. Tie it to a ring, not larger than a wedding-ring. When you apply the flame of a candle to it, it will burn to ash...