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

To tell a Person any Number he may privately fix on.

When the person has fixed on a number, bid him double it and add four to that doubling; then multiply the whole by 5; to the product let him add 12, and multiply the amount by 10. From the total of all this, let him deduct 320, and tell you the remainder; from which, if you cut off the two last figures, the number that remains will be what he fixed upon. For instance,

Suppose the number chosen is	7
Which doubled	14
Add 4 to it, and it will make	18
Multiply 18 by 5, gives	90
To which add 12, is	102
Multiply that by 10, makes	1020
From which deducting 320, the remainder is	700
And by striking off the two ciphers, it becomes the number thought on	7

To tell any Number a Person has fixed on, without asking him any Questions.

You tell the person to choose any number from 1 to 15; he is to add 1 to that number, and triple the amount. Then,

1. He is to take the half of that triple, and triple that half.
2. To take the half of the last triple, and triple that half.
3. To take the half of the last triple.
4. To take the half of that half.

Thus, it will be seen, there are four cases where the half is to be taken; the three first are denoted by one of the eight following Latin words, each word being composed of three syllables; and those that contain the letter i refer to those cases where the half cannot be taken without a fraction; therefore, in those cases, the person who makes the deduction is to add 1 to the number divided. The fourth case shows which of the two numbers annexed to every word has been chosen; for if the fourth half can be taken without adding 1, the number chosen is in the first column; but if not, it is in the second.

The words.	The numbers they denote.
Mi-se-ris	8	0
Ob-tin-git	1	9
Ni-mi-um	2	19
No-ta-ri	3	11
In-fer-nos	4	12
Or-di-nes	13	5
Ti-mi-di	6	14
Te-ne-ant	15	7

For example:

Suppose the number chosen is	9
To which is to be added	1
	——
	10
The triple of that number is	30
The half of which is	15
The triple of that half must be	45
And the half of that[A]	23
The triple half of that half	69
The half of that[A]	35
And the half of that half[A]	18