Refraction Of Light
In the middle of an empty basin put a piece of money, and then retire
from it till the edge of the basin hides the piece from your sight:
then keep your head steady, let another person fill the basin gently
with water; as the water rises in the basin the money will come in
view; and when of a sufficient height in the basin, the whole of the
piece will be in sight.
More
-
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... Of Gunpowder &c
Gunpowder being a principal ingredient in fire-works, it will not be improper to give a short definition of its strange explosive force, and cause of action, which, according to Dr. Shaw's opinion of the chemical cause of the explosive force of gunp... Of Lightning And The Best Method Of Guarding Against Its Mischievous
Effects. Experiments made in electricity first gave philosophers a suspicion, that the matter of lightning was the same with the electric matter. Experiments afterwards made on lightning obtained from the clouds by pointed rods, received into bottl... Of Mixing The Composition The Performance Of The Principal Part Of
fire-works depends much on the compositions being well mixed; therefore, great care must be taken in this part of the work, particularly for the composition for sky-rockets. When you have four or five pounds of ingredients to mix, which is a sufficien... Of Painting The Glasses
You first draw on a paper, the size of the glass, the subject you mean to paint; fasten this at each end of the glass with paste, or any other cement, to prevent it from slipping. Then with some very black paint mixed with varnish, draw with a fine ... Of Saltpetre
Saltpetre being the principal ingredient in fire-works, and a volatile body by reason of its aqueous and aerial parts, is easily rarefied by fire; but not so soon when foul and gross, as when purified from its gross and earthy parts, which greatly r... Of Such Ingredients As Show Themselves In Sparks When Rammed Into
choked Cases. The set colours of fire produced by sparks are divided into four sorts, viz., the black, white, grey, and red; the black charges are composed of two ingredients, which are meal-powder and charcoal; the white of three, viz., saltpetre,... Of Sulphur Or Brimstone
Sulphur is by nature the food of fire, and one of the principal ingredients in gunpowder, and in almost all compositions of fire-works; therefore, great care ought to be taken of its being good, and brought to the highest perfection. Now, to know wh... Of The Method Of Mixing Compositions
The performance of the principal part of fire-works depends much on the compositions being well mixed; therefore, great care ought to be taken in this part of the work, particularly in the composition for sky-rockets. When you have four or five poun... Opaque Bodies Seemingly Transparent
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 perpendicular, as in the figure. In each of the two extremities A B, make... Pipes Of Communication For Water
They may be used under water, but must be a little thicker in the paper than those for land. Having rolled a sufficient number of pipes, and kept them till dry, wash them over with drying oil, and set them to dry; but when you oil them, leave about ... Plural Wheels Plural Wheels Are Made To Turn Horizontally And To
consist of three sets of spokes, placed six at top, six at bottom, and four in the middle; which last must be a little shorter than the rest: let the diameter of the wheel be 10 inches: the cases must be tied on the ends of the spokes in grooves cut o... Refraction Of Light
In the middle of an empty basin put a piece of money, and then retire from it till the edge of the basin hides the piece from your sight: then keep your head steady, let another person fill the basin gently with water; as the water rises in the basi... Remarkable Effects On The Visual Nerves By Looking Through
differently-coloured Glasses. After looking through green spectacles, the white paper of a book will, on first taking them off, appear to have a blush of red; and after looking through red glasses, a greenish cast. This seems to intimate a relation... Remarkable Properties In Certain Plants
Plants, when forced from their natural position, are endowed with a power to restore themselves. A hop-plant, twisting round a stick, directs its course from south to west, as the sun does. Untwist it, and tie it in the opposite direction, it dies. ... Resin Ignited By Electricity
Wrap some cotton wool, containing as much powdered resin as it will hold, about one of the knobs of a discharging-rod. Then having charged a Leyden jar, apply the naked knob of the rod to the external coating, and the knob enveloped by the cotton to... Scrolls For Rockets Cases For Scrolls Should Be Made Four Or Five
inches in length, and their interior diameters three-eighths of an inch: one end of these cases must be pinched quite close before beginning to fill; and when filled, close the other end; then in the opposite sides make a small hole at each end, to th... Secret Correspondence
To carry on a correspondence without the possibility of the meaning of the letter being detected, in case it should be opened by any other person, has employed the ingenuity of many. No method will be found more effectual for this purpose, or mor... Secret Correspondence By Music
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 circumference is to be ruled like music-paper. Place in each division a not... Several Different Cards Being Fixed On By Different Persons To Name
that on which each Person fixed. There must be as many different cards shown to each person, as there are cards to choose; so that, if there are three persons, you must show three cards to each person, telling the first to retain one in his memory.... Single Vertical Wheels There Are Different Sorts Of Vertical
wheels; some having their fells of a circular form, others of an hexagonal, octagonal, or decagonal form, or of any number of sides, according to the length of the cases you design for the wheel; the spokes being fixed in the nave, nail slips of tin, ... Singular Impression On The Visual Nerves By A Luminous Object
If, while sitting in a room, you look earnestly at the middle of a window, a little while, when the day is bright, and then shut your eyes, the figure of the window will still remain in your eye, and so distinct that you may count the panes. A remar... Sky-rockets
Rockets being of the fire-works most in use, we shall give them the preference in description. As the performance of rockets depends much upon their moulds, they should be made according to the following proportions:--Taking the diameter of the orif... Spiral Wheels They Are Only Double Horizontal Wheels And Made
thus: the nave must be about six inches long, and rather thicker than the single sort; instead of the pintle at top, make a hole for the case to be fixed in, and two sets of spokes, one set near the top of the nave, and the other near the bottom. At t... Spirits Ignited By Electricity
Hang a small ball with a stem to the prime conductor, so that the ball may project below the conductor. Then warm a little ardent spirit, by holding it a short time over a candle in a metallic spoon; hold the spoon about an inch below the ball, and ... Spur Fire
This fire is the most beautiful of any composition yet known. As it requires great trouble to bring it to perfection, particular care must be paid to the following instructions. They are made generally in cases about six inches long, but not driven ...