Part 6 (1/2)

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

[A] At all these stages, 1 must be added, to take the half without a fraction.

While the person is performing the operation, you remark, that at the second and third stages he is obliged to add 1; and, consequently, that the word _ob-tin-git_, in the second and third syllables of which is an i, denotes that the number must be either 1 or 9; and, by observing that he cannot take the last half without adding 1, you know that it must be the number in the second column. If he makes no addition at any one of the four stages, the number he chose must be 15, as that is the only number that has not a fraction at either of the divisions.

_The Lamp Chronometer._

Figure 4 represents a chamber lamp, A, consisting of a cylindrical vessel made of tin, in the shape of a candle, and is to be filled with oil. This vessel should be about three inches high and one inch diameter, placed in a stand, B. The whole apparatus, of lamp and stand, can be purchased, ready-made, at any tin-shop in London. To the stand, B, is fixed the handle C, which supports the frame D, about 12 inches high, and four inches wide. This frame is to be covered with oiled paper, and divided into 12 equal parts by horizontal lines, at the end of which are written the numbers for the hours, from 1 to 12, and between the horizontal lines, and diagonals, divided into halves, quarters, &c. On the handle C, and close to the gla.s.s, is fixed the style or hand E.

[Ill.u.s.tration: Fig. 4.]

Now, as the distance of the style from the flame of the lamp is only half an inch, then, if the distance of the frame from the style be six inches, while the float that contains the light descends by the decrease on the oil, one inch, the shadow of the style of the frame will ascend 12 inches, being its whole length, and show by its progression, the regular increase of the hours, with their several divisions.

You must be careful always to burn the same oil, which must be the best; and the wick must never vary in size; if these precautions are not attended to, the dial never can be accurate.

_The Phial of the Four Elements._

Take a phial, six or seven inches long, and about three quarters of an inch in diameter. In this phial put, first, gla.s.s coa.r.s.ely powdered; secondly, oil of tartar per deliquum; thirdly, tincture of salt of tartar; and lastly, distilled rock oil.

The gla.s.s and the various liquors being of different densities, if you shake the phial, and then let it rest a few moments, the three liquors will entirely separate, and each a.s.sume its place; thus forming no indifferent resemblance of the four elements, earth, fire, water, and air: the powdered gla.s.s (which should be of some dark colour) representing the earth; the oil of tartar, water; the tincture, air; and the rock oil, fire.

_The Magic Bottle._

Take a small bottle, the neck of which is not more than the sixth of an inch in diameter. With a funnel, fill the bottle quite full of red wine, and place it in a gla.s.s vessel, similar to a show-gla.s.s, whose height exceeds that of the bottle about two inches; fill this vessel with water. The wine will shortly come out of the bottle, and rise in the form of a small column to the surface of the water; while at the same time, the water, entering the bottle, will supply the place of the wine. The reason of this is, that as water is specifically heavier than wine, it must hold the lower place, while the other rises to the top.