The Book of Curiosities

by John Platts

No. V.

					22
				24		17
			26		16		49
		23		18		48		55
	25		20		31		54		60
27		21		30		53		0		5
	19		29		52		58		0
		28		51		57		0
			50		0		0
				0		0
					56

No. VI.

					38
				40		34
			39		32		49
		41		35		48		55
	43		37		47		54		60
42		33		46		53		0		59
	36		45		52		0		0
		44		51		57		0
			50		0		0
				56		0
					58

You deliver the cards to a person, and desire him to think of any number from one to sixty; he is then to look at the cards, and say in which cards the number he thought of is to be found; and you immediately tell him the number thought of.

Explanation.

This surprising and ingenious recreation is done by means of a key number. There is a key number in every card, viz. the last but one in the second row from the top. From this explanation the reader will perceive that the key numbers are 1, 2, 4, 8, 16, 32. Now whatever number is fixed on, from 1 to 60, will be readily found by privately adding together the key numbers of the cards that contain the number thought on. For instance, suppose a person thinks of number 43; he looks at the cards, and gives you No. 1, 2, 4, 5, 6, as cards which contain the number thought on: you expertly perceive that the key numbers are 1, 2, 8, 32; which numbers added together make 43, the number thought on. Suppose he thinks of No. 15, he gives you No. 1, 2, 3, 4: the key numbers are 1, 2, 4, 8; which added, make just 15; and so of all numbers from 1 to 60.

This recreation may be varied many ways; as, telling the age of a person, &c.; but this is left to the ingenious reader’s taste and application.

Cheap and Easy Method of constructing a Voltaic Pile.

Mr. Mitchell, in his useful little work on natural philosophy, proposes the following cheap and easy method of constructing a Voltaic Pile. Zinc is one of the cheapest of metals, and may be easily melted, like lead. Let the student cast twenty or thirty pieces, of the size of a penny-piece, which may easily be done in moulds made in clay. Let him then get as many penny-pieces, and as many pieces of paper, or cloth cut in the same shape, and these he must dip in a solution of salt and water. In building the pile, let him place a piece of zinc, wet paper, (the superabundant water being squeezed out,) after which the copper; then zinc, paper, copper, &c. until the whole be finished. The sides of the pile may be supported with rods of glass, or varnished wood, fixed in the board on which it is built. The following experiment may then be performed:—