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 gun is discharged at a distance,
we see the fire long before we hear the sound; if, then, we know the
distance of the place, and know the time of the interval between our
first seeing the fire, and then hearing the report, this will show us
exactly the time the sound has been travelling to us. For instance, if
the gun be discharged a mile off, the moment the flash is seen I take
a watch and count the seconds till I hear the sound; the number of
seconds is the time the sound has been travelling a mile.
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Example Suppose The Three Cards To Be Ten Seven And Six As
before; then, each of those numbers subtracted from seventeen, the remainders will be respectively, seven, ten, and eleven, which, added together, make twenty-eight, to which the single card you drew being reckoned as one, and added, makes twenty-nine... Example Suppose The Two Cards To Be As Before Ten And Seven Then
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, which you subtract from fifty-two; and there must remain seventeen for th... Experiments With Sparrows
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 found, First.--That in atmospheric air, HOURS MIN. The firs... Exploding Gas Bubbles
Adapt the end of a common tobacco-pipe to a bladder filled with hydrogen gas, and dip the bowl of the pipe into soap-suds, prepared as if for blowing up soap bubbles; squeeze out small portions of gas from the bladder into the soap-suds, and the bub... Exploding Salt
If a small quantity of powdered charcoal and hyper-oxymuriate of potash be rubbed together in a mortar, an explosion will be produced, and the charcoal inflamed. Three parts of this salt, and one of sulphur, rubbed together in a mortar, produce a vi... Feathers Heavier Than Lead
At one end of a fine balance, hang a piece of lead, and at the other as many feathers as will poise it; then place the balance in the receiver. As the air is exhausted, the feathers will appear to overweigh the lead, and when all the air is drawn of... Fire Globes For The Water
Bowls for water-globes must be very large, and the wheels on them of ten sides: on each side nail a piece of wood four inches long; and on the outside of each piece cut a groove, wide enough to receive about one-fourth of the thickness of a four-oun... Fixed Sun With A Transparent Face
To make a sun of the best kind, there should be two rows of cases, which should show a double glory, and make the rays strong and full. The frame or sun-wheel must be made thus: have a circular flat nave made very strong, 12 inches diameter; to this... Flowers Curiously Affected By The Sun And The Weather
The petals of many flowers expand in the sun, but contract all night, or on the approach of rain; after the seeds are fecundated the petals no longer contract. All the trefoil may serve as a barometer to the husbandman; they always contract their le... Fulminating Gold
Put into a small long-necked bottle, resting on a little sand, one part of fine gold filings, and three parts of aqua regia, (nitro-muriatic acid.) When the gold is dissolved, pour the solution into a glass, and add five or six times the quantity of... Fulminating Mercury
Dissolve 100 grains of mercury by heat, in an ounce and a half of nitric acid. This solution being poured cold upon two measured ounces of alcohol previously introduced into any convenient glass vessel, a moderate heat is to be applied, till efferve... Fulminating Powder
This powder is made by rubbing together, in a hot marble mortar, with a wooden pestle, three parts, by weight, of nitre, two of mild vegetable alkali, and one of flowers of sulphur, till the whole is accurately mixed. If a drachm of this powder be e... 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...