round like a small pea, which put between your left fore-finger and
thumb. Now, hold the other out at length, between the fore-finger and
thumb of each hand, holding all your fore-fingers daintily; then let
one cut the same asunder in the middle; when that is done, put the
tops of your two thumbs together, and so shall you with less suspicion
receive the thread which you hold in your right hand into your left,
without opening your left finger and thumb. Then holding these two
pieces as you did before it was cut, let these two be cut also asunder
in the middle, and they conveyed again as before, until they be very
short; then roll all these ends together, and keep that ball of thread
before the other in the left hand, and, with a knife, thrust the same
into a candle, where you may hold it until the said ball of thread be
burnt to ashes; then pull back the knife with your right hand, and
leave the ashes, with the other ball betwixt your fore-finger and
thumb of your left hand, and, with the two thumbs and two fore-fingers
together, take pains to rub the ashes till your thread be renewed, and
draw out that thread at length, which you lay all this while betwixt
your fore-finger and thumb. This is not inferior to any juggler’s
trick, if it be well handled; for if you are so perfect in legerdemain
as to bestow the same ball of thread, and to change it from place to
place, betwixt your other fingers, as may be easily done, then it will
seem very strange.
_To pull many Yards of Ribbon out of the Mouth._
Jugglers get money from maids, by selling laces by the yard, putting
into their mouths one round bottom, as fast as they pull out another,
and, at the exact end of every yard, they tie a knot, so as the
same rests upon their teeth; then they cut off the same, and so the
beholders are doubly and trebly deceived, seeing as much lace as will
fill a hat, and the same of what colour they like, to be drawn out of
the mouth; and yet the juggler talks as though there was nothing in his
mouth.
_To cut a Piece of Tape into four Parts, and make it Whole again with
Words._
Take a piece of narrow white tape, about two or three yards long. First
present it to view to any that may desire it; then tie both the ends of
it together, and take one side of it into one hand, so that the knot
may be about the middle of one side, and, using some circumstantial
words to beguile the spectators, turn one hand about toward yourself,
and the other from you; so shall you twist the tape once, then clap
the ends together, and then, if you slip your finger and thumb of each
hand between the tape, almost as one would hold a skein of thread to
be wound, this will make one fold or twist, as thus appears, where A
signifieth the twist or fold--B the knot. Then
[Illustration]
in like manner make a second fold, about the line D C, as you may see
by the second figure, where B signifieth the knot, C the first fold,
and A the second fold; then hold the fore-finger and thumb of your left
hand upon the second twist, and upon the knot also, and the fore-finger
and thumb of your right hand upon the first fold C, and desire some
one of your spectators to cut all asunder with a sharp knife at the
cross line E D; when it is cut, hold still your left hand, and let all
the ends fall that you hold in your right hand, for there will be a
show of eight ends, four above and four below, and so the strings will
be thought to be cut into four parts, as may be seen by the third
figure; then gather up the ends that you let fall into your left hand,
and deliver two of the ends (seeming to take them at random) unto
two several persons, bidding them hold them fast, still keeping your
left-hand fingers upon the twists or folds; then with both your hands
seem to tumble all the ends together that you had in your left hand,
twist out the slips and pieces, which are three, as you may see at A
and B in the third figure,--twist them all, I say, into a little ball,
and conceal it between some of your fingers of your left hand, and
crumble thereon another confused heap, and, after some words said, with
your right hand deliver this confused heap unto any of the company,
bidding them hold it fast, saying, “_Hulla passa_;” then bid them look
on it, and while they are greedily looking after the event, you may
with ease convey the ball or roll of ends into your pocket; so it will
be thought that you have made it whole by virtue of your words. This
is an excellent trick, if it be gracefully handled: it cost me a great
deal of trouble and time to find it out.
_To unloose a Knot upon a Handkerchief by Words._
Make a plain loose knot with two ends of a handkerchief, seeming to
draw the same very hard. Hold fast the body of the handkerchief near
to the knot, with your right hand, pulling the contrary end with your
left. Then close up handsomely the knot, which will be somewhat loose,
and pull the handkerchief so with your right hand, that the left hand
may be near the knot; then will it seem to be a true and firm knot;
and to make it appear more assuredly to be so indeed, let a stranger
pull at the end which you hold in your left hand, while you hold
fast the other in your right hand, and then holding the knot with
your fore-finger and thumb, and the lower part of your handkerchief
with your other finger, as you hold a bridle when you would with one
hand slip up the knot and lengthen the reins. This done, turn your
handkerchief over the knot with your left hand; in doing whereof you
must suddenly slip out the end or corner, putting up the knot of your
handkerchief with your fore-finger and thumb, as you would put the
aforesaid knot of your bridle. Then deliver the same, covered and
wrapped within the midst of the handkerchief, to one to hold fast, and,
after the pronunciation of some words of art, take the handkerchief and
shake it, and it will be loose.
_To draw a Cord through the Nose._
This trick is called the bridle, being made of two alder sticks--
[Illustration]
Through the hollowness thereof is placed a cord, the same being put
upon the nose, like a pair of pincers or tongs; the cord which goeth
round the same being drawn to and fro, the beholders will think the
cord goes through your nose very dangerously; the knots at the end of
the cord, which stay the same from being drawn out of the stick, must
not be put at the very top, for that must be stopped up, but half an
inch beneath each end; and so, when it is pulled, it will seem to pass
through the nose. Then you may take a knife and seem to cut the cord
asunder, and pull the bridle from your nose.
_To take three Button-Moulds off a String._
Take two little whipcords, of two feet long each, double them equally,
so as there may appear four ends; then take three button-moulds
(the hole of one of them must be bigger than the rest), and put one
button-mould upon the eye or bout of one cord, and another on the other
cord; then take the button-mould with the greatest hole, and let both
the bouts be hidden therein, which may be the better done if you put
the eye, or bout, of the one
[Illustration]
into the eye or bout of the other; then put the middle button upon
the same, being doubled over his fellow: so will the heads seem to be
put over the two cords. You may loose them as you like, and make it
seem manifest to the beholders, who may not see how they are done; but
that the buttons are put upon the two cords, without any fraud. Then
must you seem to add a more effectual binding of those buttons to the
strings, and make one half of a knot with one of the ends of each side,
which is for no other purpose, but that, when the buttons are taken
away, the cords may be seen in the case which the beholders suppose to
be in before; for when you have made your half knots, which in any wise
you must not double to make a perfect knot, you must deliver into the
hands of some bystanders these two cords--namely, two cords evenly set
to one hand, and two in the other, and then with a wager begin to pull
off the buttons, which, if you handle nimbly, and in the end cause him
to pull his two ends, the two cords will show to be placed plainly, and
the buttons to have come through the cords.
OPTICAL ILLUSIONS.
_The Multiplying Mirror._
A mirror is to be made as follows: first make a hoop or fillet of wood
about the width of a half-crown piece, and let the thickness be about
a quarter of an inch. In the middle of this hoop fasten a bottom of
wood or brass, and place several hooks of the size of small peas. Then
open the one side of this bottom, set in a piece of crystal glass, and
fasten it in the hoop close to the bottom;
[Illustration]
then take a quantity of quicksilver, and put so much into the hoop as
will cover the bottom; then let into the hoop another piece of crystal
glass fitted thereto, and cement the sides that the quicksilver may not
run out, and it is done,--the use whereof I shall not insist upon,
since he that is versed in optical illusions will better conceive it,
than any words of mine can either direct or assist him.
_The Magic-Lantern._
This lantern is called magical on account of the formidable apparitions
that, by virtue of light, show upon the white wall of a dark room.
The body of it is generally made of tin, and of the shape of a lamp.
Towards the back is a concave looking-glass of metal, which may either
be spherical or parabolical, and which, by a grove made in the bottom
of the lantern, may be either advanced nearer or put farther back from
the lamp, in which is oil or spirit of wine; and the match ought to be
a little thick, that when it is lighted it may cast a good light that
may easily reflect from the glass to the fore part of the lantern,
where there is an aperture with a prospective in it, composed of two
glasses, that make the rays converge and magnify the object.
When you mean to make use of this admirable machine, light the lamp,
the light of which will be much augmented by the looking-glass at a
reasonable distance. Between the fore part of the lantern and the
prospective glass you have a trough, made on purpose, in which you are
to run along a flat frame, with transparent colours on glass. Then
all these little figures, passing successively before the prospective
glass, through which passes the light of the lamp, will be painted and
represented with the same colours upon the wall of a dark room, and in
a gigantic and monstrous manner.
By this lantern you may show birds, beasts, and all sorts of fish, &c.
&c. &c.
_The Phantascope._
The Phantascope is a magic-lantern improved; that is, it will magnify
or diminish the figures it is to reflect, without impairing their
neatness.
This instrument is composed of a tin box, surmounted by a kind of
chimney, pierced on one of its faces with a hole of a diameter
corresponding with that of the cylinders, sliding into one another
like the tubes of an opera-glass: this tube is adjusted by means of a
slide established above the aperture made in the phantascope. The part
of the adjoining cylinder is so adjusted to receive alternately wooden
tablets, in which are opened cavities to contain the figures painted
upon glass. The flat side of the half ball is placed in that tube,
nearly close enough to touch the painted figures: this half ball is
called the object glass.
In the second cylinder is found a magnifying-glass, convex on both
sides, the focus whereof is double to that of the half ball, and one
third of its diameter: this glass is called “the eye-glass.” It is by
means of drawing those glasses close that the objects are magnified;
and by removing them at a distance, that the figures are made to
look smaller. Inside of the box is placed one of those lamps called
“argand,” of a wide diameter, with a concave mirror, to throw as much
light as possible upon the transparent figures.
To exhibit the phantasmagoria, select an apartment opening into a
second room, and the door of which is at your disposal: take a wooden
frame, exactly of the same dimensions as that door, upon which fasten,
with brass nails, a sheet of fine linen, in preference to calico. A
moment before you place the frame, wet it equally all over, to cause
the thread of the cloth to swell, and to fill all interstices.
When you have proved the above-mentioned instrument, prior to your
using it, make sure that the lamp does not smoke, but that it gives
a vivid light; that the concave mirror is very bright; that the
magnifying-glass is dry and clean. (You dry these with a piece of soft
leather and some whitening, so fine as not to scratch. The painted
glasses are cleaned with a piece of very fine cloth, made quite hot,
or of cambric, taking care not to rub off the painting.) You then
place the wooden ruler with the reversed figure in the slide, opened
purposely to receive it, in the first cylinder; then, the figures being
reflected on a whitewashed wall, you regulate the distance of the
magnifying-glasses, in order to have the paintings seen in all their
perfection at a regular fixed distance. Your instrument is then ready
for the exhibition.
To this effect, you present yourself facing the framed linen, with the
phantascope suspended before you, and held by two braces across your
shoulders. In order that the figures may decrease in the eyes of the
spectators of the other side, you must advance slowly near the cloth,
drawing the two magnifying-glasses at a distance from each other, but
very gently, that the figures should remain steady.
If, on the contrary, you should wish them to appear magnified,
gradually draw back, with the same precaution, and bring the glasses
nearer each other; when they are quite close, the figures seem to be
coming towards the spectators, and to proceed forward.
When you change the paintings, you must hide the eye-glass behind an
opaque and black body. The knowledge of the management of the glasses,
and the accuracy of the proceeding backward and forward, upon which
depends entirely the good effect of the exhibition, may be acquired by
a few days’ practice previous to the exhibition being made in company.
Notwithstanding the box for the phantascope, if made of wood, will be
heavier than a tin one, yet it is to be preferred, on account of its
communicating much less heat than the tin.
Such persons as wish to paint their figures should use a varnish that
does not spread on the glass; thick copal varnish will answer the
purpose.
_The Enchanted Mirrors._
Make a box of wood, of a cubical figure, of about fifteen inches every
way. Let it be fixed on a pedestal, at the usual height of a man’s
head. In each side of this box, let there be an opening of an oval
form, ten inches high, and seven wide.
In this box place two mirrors, with their backs against each other;
let them cross the box in a diagonal line, and in a vertical position.
Decorate the openings in the sides of this box with four oval frames,
and transparent glasses, and cover each of them with a curtain, so
contrived that they may all draw up together.
Place four persons in front of the four sides, and at equal distances
from the box, and then draw up the curtains, that they may see
themselves in the mirrors; when each of them, instead of his own
figure, will see that of the person who is next him, and who, at the
same time, will seem to him to be placed on the opposite side. Their
confusion will be the greater, as it will be very difficult for them to
discover the mirror contained in the box. The reason of this phenomenon
is evident; for, though the rays of light may be turned aside by a
mirror, yet they always appear to proceed in right lines.
_The Wonderful Phantoms._
In a partition make two apertures of a foot high, and ten inches wide,
and about a foot distant from each other. Let them be at the common
height of a man’s head; and in each of them place a transparent glass,
surrounded with a frame, like a common mirror.
Behind this partition place two mirrors, inclined to it in an angle
of forty-five degrees (that is, be halfway between a line drawn
perpendicular to the ground and its surface); let them be both eighteen
inches square; let all the space between them be enclosed by boards, or
pasteboard, painted black, and well closed, that no light may enter.
Let there be also two curtains to cover them, which may be drawn aside
at pleasure.
When a person looks into one of these supposed mirrors, instead of
seeing his own face, he will perceive the object that is in front of
the other; so that, if two persons present themselves at the same time
before these mirrors, instead of each one seeing himself, they will
reciprocally see each other.
Note.--There should be a sconce, with a candle placed on each side of
the two glasses in the wainscot, to enlighten the faces of the persons
who look in them; otherwise this experiment will have no remarkable
effect.
This curious trick may be considerably improved, by placing the two
glasses in the partition in adjoining rooms; and, a number of persons
being previously placed in one room, when a stranger enters the other,
you may tell him his face is dirty, and desire him to look in the
glass, which he will naturally do; and on seeing a strange face he will
draw back; but, returning to it, and seeing another, and another, like
the phantom kings in Macbeth, what his surprise will be is more easy to
conceive than express. After this, a real mirror may be privately let
down on the back of the glass, and, if he can be prevailed to look in
once more, he will then, to his further astonishment, see his own face,
and may be told, perhaps persuaded, that all he thought he saw before
was mere imagination.
How many tricks, less artful than this, have passed in former times for
sorcery, and pass at this time, in some countries, for apparitions!
Note.--When a man looks in a mirror that is placed perpendicular to
another, his face will appear entirely deformed. If the mirror be a
little inclined, so as to make an angle of eighty degrees (that is,
one ninth part from the perpendicular), he will then see all the parts
of his face, except the nose and forehead. If it be inclined to sixty
degrees (that is, one third part), he will appear with three noses and
six eyes: in short, the apparent deformity will vary at each degree of
inclination; and when the glass comes to forty-five degrees (that is,
half way down), the face will vanish. If, instead of placing the two
mirrors in this situation, they are so disposed that their junction may
be vertical, their different inclinations will produce other effects,
as the situation of the object relative to these mirrors is quite
different.
_The Real Apparition._
Behind a partition place, in a position somewhat oblique, a concave
mirror, which must be at least ten inches in diameter, and its distance
from the partition equal to three fourths of the distance of its centre.
In the partition, make an opening of seven or eight inches, either
square or circular: it must face the mirror, and be of the same height
with it. Behind this partition place a strong light, so disposed, that
it may not be seen at the opening, and may illumine an object placed
near it, without throwing any light on the mirror.
Beneath the aperture in the partition, place an object that you intend
shall appear on the outside of the partition, in an inverted position,
and which we will suppose to be a flower. Before the partition, and
beneath the aperture, place a little flower-pot, the top of which
should be even with the bottom of the aperture, that the eye may see
the flower in the same position as if its stalks came out of the pot.
Take care to paint the space between the back part of the partition and
the mirror black, to prevent any reflections of light from being thrown
on the mirror; in a word, so dispose the whole that it may be as little
enlightened as possible.
When a person is placed at the point of vision, he will perceive the
flower that is behind the partition, at the top of the pot; but, on
putting out his hand to pluck it, he will find that he attempts to
grasp a shadow.
_Observations._
The phenomena that may be produced by means of concave mirrors are
highly curious and astonishing. By their aid spectres of various
kinds may be exhibited. Suppose, for example, you were to tell any
one, that at such an hour, and in such a place, he should see the
apparition of an absent or deceased friend (of whose portrait you are
in possession); in order to produce this phantom, instead of the hole
in the partition, there must be a door which opens into an apartment to
which there is a considerable descent. Under that door you are to place
the portrait, which must be inverted and strongly illuminated, that it
may be properly reflected by the mirror, which must be large and well
polished. Then, having introduced the spectator at another door, and
placed him in the proper point of view, you suddenly throw open the
first door, when, to his great astonishment, he will immediately see
the apparition of his friend.
It will be objected, perhaps, that this is not a perfect apparition,
because it is only visible at one point of view, and by one person. But
it should be remembered, that it was an established maxim in the last
century, that a spectre might be visible to one person, and not to
others. So Shakespeare makes both Hamlet and Macbeth see apparitions
that were not visible to others, present at the same time. It is
not unlikely, moreover, that this maxim took its rise from certain
apparitions of the kind, _that were raised by the monks, to serve some
purposes they called religious_; as they alone were in possession of
what little learning there then was in the world.
_To draw a Deformed Figure, which will appear well proportioned from a
certain Point of View._
Draw any thing you may fancy on a thin white pasteboard; then prick it;
afterwards put the same on an horizontal surface, which we will suppose
to be another pasteboard; put a lighted candle behind that drawing, and
draw on the horizontal surface the lines given by the light; this will
give a deformed design. This being done, take away the drawing that was
pricked, and the candle; then place your eye where the light was, and
you will see your drawing assume a regular form.
CHEMICAL CHANGES.
_To change the Colour of a Rose._
Burn some sulphur under the rose, by holding underneath it a lighted
bundle of matches. This will fade the red colour, and make the flower
turn white or blanched. Its primitive colour will return in about a
couple of hours.
_To turn Water into Wine._
Take four glasses; rub one in the inside with a piece of moist alum:
let the second have a drop of vinegar in it; the third empty. Let the
fourth be filled with clean water; in your mouth put a clean rag, with
ground basil tied close in it, the bulk not to be bigger than a small
nut, which must lie between your hind teeth and your cheek; then take
some of the water that is in the glass into your mouth, and return it
into the glass that hath the drop of vinegar in it, which will cause it
to turn the perfect colour of sack wine; then turn it in your mouth
again, and chew the rag of basil between your teeth, and squirt the
liquor into the glass, and it will have the perfect colour of claret;
returning the basil into its former place, take the liquor into your
mouth again, and presently squirt it into the glass you rubbed with
alum, and it will have the perfect colour of mulberry wine.
_Arbor Dianæ; or, the Silver Tree._
This name has been given to a beautiful and curious precipitation of
silver, by means of mercury in an arborescent form. The experiment is
made by putting a soft amalgam of silver into six parts of a solution
of nitrate of silver, and four of a solution of nitrate of mercury, or--
Amalgamate in a glass mortar one quarter of an ounce of pure mercury
and half an ounce of fine silver. Insert in this amalgamation four
ounces of pure nitric acid for the solution, and increase the whole by
a pint of distilled water; mix it well, and keep it in a glass decanter
well stopped. By introducing into this liquid a lump of soft amalgam of
silver, the formation of the tree speedily takes place.
Or, if you wish to make the experiment on a smaller scale, pour about
an ounce of the above liquid into a wine-glass, into which insert a
piece of soft amalgam of silver, the size of a pea, and the effect
required will immediately be produced. The silver, separating in the
form of prismatic needles, will arrange itself so as to assume an
arborescent appearance.
_The Lead Tree._
The precipitation of a solution of acetate of lead by means of a piece
of zinc, so as to form what is commonly called the lead tree, is
perfectly analogous to this theory, but is too well known to require
illustration.
_The Tree of Mars._
Dissolve iron filings in aqua fortis moderately concentrated, till the
acid is saturated; then pour gradually into the solution a solution of
fixed alkali, commonly called oil of tartar. A strong effervescence
will take place, and the iron, instead of falling to the bottom of
the vessel, will afterwards rise, so as to cover its sides, forming
a multitude of ramifications heaped one upon the other, which will
sometimes pass over the edge of the vessel, and extend themselves on
the outside, with all the appearance of a plant. If any of the liquor
is spilt, it must be carefully collected, and be again put into the
vessel, where it will form new ramifications, which will contribute to
increase the mass of the vegetation.
_To form a Metallic Tree, in the Shape of a Fir._