Endless Amusement / A Collection of Nearly 400 Entertaining Experiments in Various Branches of Science; Including Acoustics, Electricity, Magnetism, Arithmetic, Hydraulics, Mechanics, Chemistry, Hydrostatics, Optics; Wonders of the Air-Pump; All the Popular Tricks and Changes of the Cards, &c., &c. to Which is Added, a Complete System of Pyrotechny; Or, the Art of Making Fire-works.

by Unknown

Procure a small perspective-glass, wide enough, where the object-glass is placed, to hold the following table:

1,131 2,231 3,331	10,132 11,232 12,332	19,133 20,233 21,333
4,121 5,221 6,321	13,122 14,222 15,322	22,123 23,223 24,323
7,111 8,211 9,311	16,112 17,212 18,312	25,113 26,213 27,313

Take a pack of twenty-seven cards; give them to a person, bid him fix, on one, shuffle them, and return them to you. Arrange the twenty-seven cards in three parcels, by laying one down, alternately, on each parcel; but before you lay each card down, show it to the person, without seeing it yourself. When you have completed the three parcels, ask him at what number, from one to twenty-seven, he will have his card appear, and in which heap it then is. You then look at the heap through your glass; and if the first of the three numbers, which stands against the number it is to appear at, be one, put that heap at top; if the number be at two, put it in the middle; and if it be three, put it at the bottom. Next divide the cards into three heaps, in the same manner, a second and third time, and his card will be at the number he chose.

Example.—Suppose the person wishes his card to be the twentieth from the top; and the first time of making the heaps, he says it is in the third heap; you then look at the table in the perspective, and you see that the first figure is two; you, therefore, put that heap in the middle of the pack. The second and third times, you in like manner put the heap in which he says it is, at bottom; the number each time being three. Then looking at the pack with your glass, as if to discover which the card was, you lay the cards down, one by one, and the twentieth will be the card fixed on.

The Card in the Ring.

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 the figure of a small card; and the silk must be so constructed that it may be either drawn aside or spread, by turning the stone round.

You then cause a person to draw the same sort of card as that at the bottom of the ring; and tell him to burn it in the candle. Now, the ring being so constructed that the silk conceals the card underneath it, you first show him the ring, that he may see it is not there, and tell him you will make it appear; then rubbing the ashes of the card on the ring, you manage to turn the stone or glass dexterously round, and exhibit to him the small card at the bottom.

The Card in the Mirror.

Provide a mirror, either round or oval, the frame of which must be at least as wide as a card, and the glass must be wider than the distance between the frame, by at least the width of a card. The glass in the middle must be made to move in two grooves, and so much of the quicksilver must be scraped off, as is equal to the size of a common card. You then paste over the part where the quicksilver is rubbed off, a piece of pasteboard, on which is a cord, that must exactly fit the space, which must at first be placed behind the frame.