M A G N E T I S Mi 
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proper diredlion 5 cover thefe grooves and the face of the 
fquares with itrong paper, in order to conceal the bars. 
You tmift all'o provide a narrow box, capable of contain¬ 
ing in its breadth one of thefe fquares, and of fuch a length 
that they can all be arranged in it. 
Then defire a perfon in your abfence to take feveral of 
thefe fquares, and arrange them in the box in any manner, 
at pleafure, fo as to form any number whatever, and to 
fbut the box ; after which are you to tell the number 
which has been formed. Depofit your pretended telefcope 
on the place of the firft fquare, that is on the left, if the 
figure below it be unity; the needle will turn in fuch a 
manner, that the north point or pole will be before you. 
If the figure be 4, it will turn to the fourth divifion of the 
circle, which is equally divided into ten parts; and fo of 
the reft. It will thence be eafy to difcover the figure in 
each place, and confequentiy to tell it. 
A word written in iecret, with given characters, may 
be difcovered in the fame manner; alio an anagram, formed 
of a propoled word, as Roma , which gives amor, mora, orma, 
maro, &c. or a queftion which has been feleCted, from fe¬ 
veral perfons, and put into the box. In fiiort, this trick 
-may be varied, in a great many ways, exceedingly agreea¬ 
ble, but all depending on the lame principle. 
The box of metals, for example, is only a fimilar varia¬ 
tion of the fame trick. You put fix plates of different 
metals in a box, and bid a perfon take any one of them, 
and put it into another box, and (hut it. You may then 
eafily tell which one he has taken. Thefe plates are of 
i'uch a form, that they can occupy in the final] box only 
one pofition. Each of them, that of iron excepted, con¬ 
tains in its thicknefsa magnetic bar, arranged in fituations 
which are known, and thefe fituations are difcovered by 
means of the pretended magic telefcope; confequentiy the 
nature of the metal muft be known. No magnetic bar is 
placed in the plate of iron, becaufe this would be ufelefs; 
but one fide of the plate may be magnetifed, or, if it be 
not magnetifed, the indeterminate direction of the needle 
will announce that it is iron. 
4. The Magnetic Dial. —Provide a circle of wood or ivory, 
of about five or fix inches diameter, as fig. 27, which mult 
turn quite free on the ftand B, fig; 28, on the circular 
border A: on the circle muft be placed the dial of palte- 
boards C, (fig. 28,) whole circumference is to be divided 
into 12 equal parts, in which muft be infcribed the num¬ 
bers from 1 to 12, as on a common dial. There muft be 
a fmall groove in the circular frame D, to receive the palte- 
board circle ; and obferve that the dial muft be made to turn 
fo freely, that it may go round without moving the circu¬ 
lar border in which it is placed. Between the paiteboard 
circle and the bottom of the frame, place a fmall artificial 
magnet that has a hole in its middle, or a fmall protuber¬ 
ance. On the outfide of the frame place a fmall pin P, 
which ferves to {how where the magnetic needle I, that is 
placed on a pivot at the centre of the dial, is to flop. 
This needle muft turn quite freely on its pivot, and its 
two fides ftiould be in exa <51 equilibrium. Then provide 
a fmall bag, that has five or fix divifions, like a lady’s 
work-bag, but fmaller. In one of thefe divifions put fmall 
fquare pieces of paiteboard on which are written the num¬ 
bers from 1 to 12; and if you pleafe you may put feveral 
of each number. In each of the other divifions you muft 
put 12 or more like pieces, obferving, that all the pieces 
-in each divifion mult be marked with the fame number. 
Nov/, the needle being placed upon its pivot, and turned 
quickly about, it will neceffarily Hop at that point where 
the north end of the magnetic bar is placed, and which you 
previoufly knew by the lituation of the fmall pin in the 
circular border. You therefore prefent to any perfon that 
divifion of the bag which contains the feveral pieces on 
which is written the number oppolite to the north end of 
the bar, and tell him to draw any one of them he pleafes. 
Then, placing the needle on the pivot, you turn it quickly 
about; and it will neceflarily Itop, as we have already laid, 
at that particular number, 
Another experiment may be made with the fame dial, 
by defiling two perfons to draw each of them one num¬ 
ber out of two different divifions of the bag; and, if their 
numbers, when added together, exceed 12, the needle or 
index will flop at the number they exceed it; but, if they 
do not amount to 12, the index will ftop at the Aim of 
thole two numbers. In order to perform this, experi¬ 
ment, you muft place the pin againft the number 5, if 
the two numbers to be drawn from the bag be 10 and 
7; or againft 9, if they be 7 and 2. If this experi¬ 
ment be made immediately after the former, as it c-afily 
may, by dexteroufly moving the pin, it will appear the 
more extraordinary. 
5. The Magnetic Table. —Under the top of a common ta¬ 
ble place a magnet that turns on a pivot; and fix a board 
under it, that nothing may appear. There may alfo be a 
drawer under the table, which you pull out to ftiow that 
there is nothing concealed. At one end of the table 
there mult be a pin that communicates with the magnet, 
and by which it may be placed in different politions; this 
pin mult be fo placed as not to bevilibleto the fpcdtators. 
Strew fome fteel filings or very fmall nails over that part of 
the table where the magnet is. Then aik any one to lend 
you a knife or a key, which will then attract part of the 
nails or filings. Then, placing your hand in a carelefs 
manner on the pin at the end of the table, you alter the 
pofition of the magnet, and, giving the key to any perfon, 
you defire him to make the experiment, which he will 
then not be able to perform. You then give the key to 
another perfon, at the lame time placing the magnet, by 
means of the pin, in the firlt pofition, when that perfou 
will immediately perform the experiment. 
6. The Myjhrious Watch.— You defire any one in com¬ 
pany to lend you a watch for a few minutes, alking him 
whether it will continue to go when laid on the table. 
He will probably fay it will. To prove to him that he is 
wrong, you lay it on that part of the table below which 
you have previoufly placed a Itrong bar-magnet, fo that 
the watch may be above one of the poles. It will imme¬ 
diately flop. Now, if you fliift the pofition of the mag¬ 
net, and give the watch to another perfon to lay it on the 
table, it will not ftop ; but, replacing the magnet, and de¬ 
firing a third perfon to try the experiment, he will fuc- 
ceed. All this, to thofe who are not acquainted with 
the fecret, will appear very extraordinary; but it is to be 
obferved, that, lhould the watch by chance be furnilhed 
with a brafs balance, the experiment will fail ; for the 
magnet adts upon the fteel of which a watch-balance is 
ul'ually made, and obltrudls its progrefs. 
7. The Magnetical Paradox.—Upon the table AB, fig. 29, 
place a piece of iron wire, not above a tenth of an inch 
long. Let the magnetic bar, EF, be held at about four 
or five inches above the table, with either pole downwards, 
and in fuch a place, as thUt the perpendicular let fall from 
it to the table may touch the table at G,viz. two or three 
inches diftance from the iron wire; thefe diftances, how¬ 
ever, are iubjedt to a good deal of variety, arifing from 
the power of the magnet. By the adlion of the magnet 
the iron wire will elevate one of its ends, as reprefented 
by CD, forming with the table an angle, which is larger 
the nearer the wire comes to the point G, where it 
Hands quite eredt. In this lituation, if you give gentle 
knocks to the table, the wire, CD, will gradually pro¬ 
ceed towards G, every knock making it jump up and 
advance a little way. The realbn of which a l'uperficial 
oblerver would immediately attribute to the attradlion 
between the magnet and the iron wire, which, being 
not fufficiently Itrong to raife the wire from the table, 
has juft power enough to draw it a little nearer to 
the point G, when the motion of the table lifts it up. 
Thus far the experiment ftiows nothing extraordinary j 
but, if it be.repeated with only this variation, viz. that 
the magnet, inltcad of being held above the table, be 
placed below ii, viz. at HI, the event will be, that the 
wire, which will now make an obtufe angle towards G, 
.as 
