Chapter I: Front Matter (1)

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.

THE WHOLE SO CLEARLY EXPLAINED AS TO BE WITHIN THE
REACH OF THE MOST LIMITED CAPACITY.

With Illustrations.

FROM THE SEVENTH LONDON EDITION.

PHILADELPHIA:
LEA AND BLANCHARD.
1847.

CONTENTS.

Page
Aces, the convertible 117
AEolipiles 60
Aigrettes 185
Air-pump 77
bottles broken by 77
glass broken by 77
hand fixed by 77
water boiled by 78
bubbles, vegetable 78
electrified 98
Alarum 147
Alphabet, changes of, in square Yards 59
Apparition, armed 126
Atmosphere, to show the Pressure of 137
Aurora Borealis, electric 91

Bacchus, animated 81
Ball, electrified 97
electric 99
Balloon, artificial 81
electric 96
Cases in Fire-works 184
Balloons, Paper, to construct 42
in Fire-works, to load with Stars, Serpents, &c. 184
Balls, dancing 93
Barley, the Awn of, an Hydrometer 157
Bell, magic 79
Bladder, exploded 80
cemented 81
Blue, to change to White 35
Bodies, two inodorous, become pungent by Mixture 145
Body, combustible, to ignite by reflection 57
Bottle, magic 48
enchanted 59
Bronzing, the Art of 133
Bubble, exploding 13
Bubbles, aerial 78
Burning-glasses, account of two 32
Busts, talking 61
Butterflies, to take Impressions of on Paper 134

Cameleon Spirit 23
Camera Obscura, to construct 16
Camphor, electrified 100
Candle lighted by electricity 84
Bombs 84
Card, divining 107
numerical 108
hit upon by guess 109
found by the Point of a Sword 109
changed by Word of Command 109
in the Ring 112
in the Mirror 113
in the Opera-glass 113
discovered by the throw of a Die 115
under the Handkerchief 117
to tell that a person has touched 117
in the Pocket-book 118
in the Egg 118
discovered by the Touch or Smell 119
Cards, magnetic 71
Amusements with 101
Points on three, to name, &c. 101
to tell how many taken from a Pack 102
to name several fixed on 104
to name the Rank of, drawn from a Piquet Pack 104
to tell the Numbers of any two 105
three 106
four confederate 108
to separate the two Colours of a Pack of, at one Cut 114
metamorphosed 114
Number of, told by their Weight 116
to change, that several persons have drawn from the
Pack 116
inverted 119
transmutable 119
convertible 120
Cascade, magical 50
musical 148
of fire, to represent 151
Cement, never-yielding 37
Changes on twelve Bells 58
Charcoal for Fire-works 164
Chase, magic 88
Coins, to take impressions of 44
Compositions for Fire-works, method of mixing 168
Concerto, solar 62
Cork heavier than Lead 81
Correspondence, secret 18, 25
by music 20
Coruscations, artificial 136
Cotton electrified 92
Crackers, to make 169
Cylinder, illuminated 91

Dance, magic 86
Dancer, hydraulic 49
Detonating works 190
Girdle 190
Balls 191
Tape 191
Cards 191
Dial, magnetic 71
Dodecahedron in Fire-works 187
Duplicates, ten 102

Earthquake, artificial 22, 86, 187
Eclipse of the Sun, to observe 129
Egg, to form Figures on, in Relief 35
Eggs, white of, contains an Alkali 144
Electric effects of a Russian climate 30
Electricity, experiments in 83
Resin lighted by 95
Spirits ignited by 95
Eolian Harp, to make 137
Exhalations, subaqueous 137
Explosion, brilliant, under Water 54
Explosion, magical 86
electric 98

Feather, animated 83
Feathers heavier than Lead 79
Figures, two, one blows out, and the other re-lights a Candle 39
Fire produced by the mixture of two cold Liquids 13
from Cane 136
Fire-pumps in Fire-works 186
Fire-works in miniature 27
imitative 149
Art of making 163
aquatic 192
Flash of Lightning, to resemble on entering a Room 37
Flower, to produce the Appearance of, from its Ashes 149
Flowers, restored 26
to diversify the Colours of 141
Fountain, fiery 44
globular 48
illuminated 51
which acts by the Heat of the Sun 52
magic 80
electrical 87
Fountains, Chinese, in Fire-works 187
Fruit, withered, restored 78
Fulminating Powders 33
more powerful 34
Gold 40
Mercury 54

Gas Bubbles, exploding 160
Ghastly Appearance, to give to Persons in a Room 35
Glass, so to fill with Water that it cannot be removed without
spilling the whole 38
Gold Chain, old, to make look like new 43
to give Silver the Colour of 43
Guinea, penetrative 132
Gunpowder 165
exploded by reflection 125
Brimstone and Charcoal, to meal for Fire-works 165

Halo, artificial 80
Horn, to make Moulds of 134
to soften 134
Hour of the Day or Night told by a suspended Shilling 152
Hydrogen Gas, to procure 159
to fill a Bladder with 159

Illuminations, artificial 22
chemical 36
Illusion, alternate 146
Incendiary, unconscious 88
Indromacus 103
Ink, invisible 23
Gold, Silver, Yellow, Red, Green, Violet,
and Grey 24, 25
secret Correspondence by Means of 25
golden 41
white 42
Iron, transformed into Copper 36
Silver 36
melted in a Moment and run into Drops 37
or Steel, to soften 135
Ivory, to cast Figures in Imitation of 134

Kings, the four inseparable 116
Kite, electric 87

Lamp to burn twelve Months without replenishing 29
Chronometer 46
Landscape, artificial 66
to draw correctly 67
Lead, metallic, produced from the Powder 141
Leech, a Prognosticator of Weather 157
Leyden Phial 94
Light, rays of 143
refraction of 144
travelling of 145
Lightning, artificial 14
its wonderful Nature 144
to guard against 153
Liquor that shines in the Dark 40
luminous 41
Luminaries, miraculous 89

Magic Lantern, Experiment with the 62
Glasses to paint 63
solar 60
Magnetism, Experiments in 70
Memory, artificial 158
Microscope, Experiment for the 145
Mirror, Magician's 124
perspective 124
distorting 126
oracular 152
Mirrors, magical 53
deforming 123
igniting 125
Money augmented by optical Illusion 15
melted in a Walnut-shell 40
Mortars, in Fire-works 184

Neptune in his Chariot 198
Number, to tell any, privately fixed on 45
without asking questions 45
divisible by 9, &c. 55
Numbers, to find the difference of two, &c. 56

Objects, three, discernible only with both Eyes 15
Oil upon Water, and Water upon Oil, curious Effects of 161
and Water, Experiments with 161
Opaque Bodies, seemingly transparent 121
Box made transparent 130
Opera-glass, diagonal 129
Oracle, inanimate 61
Orrery, magnetic 72
electrical 92, 99

Palace, enchanted 120
Parties, three magical 110
Paradox, dioptrical 127
Pass, how to make the 107
Perspective-glass, divining 111
Phantom 126
Phial of the four Elements 48
Philosophical Candle 37
Phosphorus Match Bottles 34
inflammable 53
Phosphorus, illuminated 97
Picture, magic 13
Pictures of Birds, to make, with their natural Feathers 132
Pieces, transposable 131
Plants, remarkable Properties in 138
Plaster of Paris cast, to take from a Person's Face 135
Pomatum, to make, with Wax and Water 36
Portrait, miraculous 85
Powder, which catches Fire when exposed to the Air 39
Prints, to remove Stains from 38
Prospect, boundless 57
Prospects, illuminated 68
Pyrotechny, a complete system of 163

Rain and Hail, artificial 28
Gauge, to make 142
Rainbow, artificial 60
Reflector, magnifying 16
Ring, to suspend by a Thread after the Thread has been burnt 35
on the Finger, to name, &c. 49
Roman Candles, in Fire-works 186
Rocket Stars 173
to fix one on the Top of another 174
Rockets 170
Method of rolling 170
Composition for 171
to drive 171
Decorations for 172
Caduceous 175
Honorary 175
which form an arch in rising 176
to make several rise together 176
to fix several on the same Stick 177
to fire without Sticks 178
Scrolls for 179
Stands for 179
Table 179
Water 192
Rose, changeable 41
Resin lighted by Electricity 95

Salt, exploding 127
Saltpetre for Fire-works 164
Saltpetre, to pulverize for Fire-works 164
Sealing-wax spun into Threads by Electricity 100
Sea-fight, &c. in Aquatic Fire-works 196
Serpents, for Fire-works, to make 169
Shillings, a Person having an even number of in one Hand, and
an odd Number in the other, to tell in which Hand the
odd or even Number is 17
Shock, inconceivable 88
Shower, mercurial 80
fiery 90
Silver-plate, to give a Lustre to 44
extracted from a gilded Ring 135
Sky-rockets 170
to fire under Water 198
Sound, travelling of 141, 142
Sparks, electric 93
in choked Cases 167
Sparrows, Experiments with 82
Spectre on the Table 64
Spider, artificial 84
Spirit, Cameleon 23
Spots in the Sun's Disk, to show 128
Spur-fire 166
Square Yards, to contain the Changes of the Alphabet 59
Squares, Magic 55
Squibs, to make 169
Stars, with Points, in Fire-works 188
Steam, Power of 31
Steel or Iron, to soften 135
Stone, floating 78
Storm at Sea, to represent by the Magic Lantern 63
Sulphur for Fire-works 163
Sun, fixed, with a transparent Face 189
Sun's Rays, Effects of, on different coloured Cloths 146
Swans and Ducks in Aquatic Fire-works 199

Tantalus, Cup of 85
Thunder, artificial 14, 15
Touch-paper, to make 167
Transcolorations, curious 29, 30
Transmutations, magical 35
Travelling of Sound 141, 142
Light 145
Tree, Silver 27
Tree, Lead 27
Iron 55
sublimated 139
Tube, Magic 123
Tulip, Experiment with 140

Vacuum, illuminated 90
Vase, Magic 110
Vessel, Magic 21
that lets Water out of the Bottom as soon as the
Mouth is uncorked 39
Verse, Magic 74
Viper, Experiment with 82
Visual Nerves, singular Impression on, by a luminous Object 160
by looking through
differently-coloured Glasses 161
Volcano, artificial 22

Wand, magnetic 70
mercurial 79
Watch Dial, to tell by one the Hour when a Person intends
to rise 17
mysterious 70
Lamp 140
Water gilding on Silver 43
which gives Silver a Gold Colour 43
to give any Metal a Gold Colour 43, 44
Sun 50
illuminated 96
colder than Ice 127
Experiment with a Glass of 135
beautifully transparent 142
Power of 143
in Steam 158
Pressure of 143
Mass of, contained in the Sea 145
Rockets 192
Wheels, horizontal 193
Pipes in Fire-works 193
Mines 194
Fire Globes 194
Balloons, odoriferous 195
Fire Fountains 200
Weather, to foretel 140
Table 162
Wheels, self-moving 79, 94
in Fire-works 180
single vertical 180
horizontal 181
plural 182
spiral 182
Balloon 183
double spiral 183
illuminated spiral 183
Winter, changed to Spring 26
Writing, mysterious 26
illuminated 28
burnt, restored 129
in the Dark, to make luminous 139
on Glass by the Rays of the Sun 148

ENDLESS AMUSEMENT.

_To produce Fire by the Mixture of two cold Liquids._

Take half a pound of pure dry nitrate, in powder; put it into a retort that is quite dry; add an equal quantity of highly rectified oil of vitriol, and, distilling the mixture in a moderate sand heat, it will produce a liquor like a yellowish fume; this, when caught in a dry receiver, is _Glauber's Spirits of Nitre_; probably the preparation, under that name, may be obtained of the chemists, which will of course save much time and trouble.

You then put a drachm of distilled oil of cloves, turpentine, or carraways, in a glass vessel; and if you add an equal quantity, or rather more, of the above spirit, though both are in themselves perfectly cold, yet, on mixing them together, a great flame will arise and destroy them both, leaving only a little resinous matter at the bottom.

_The Exploding Bubble._

If you take up a small quantity of melted glass with a tube, (the bowl of a common tobacco-pipe will do,) and let a drop fall into a vessel of water, it will chill and condense with a fine spiral tail, which being broken, the whole substance will burst with a loud explosion, without injury either to the party that holds it, or him that breaks it; but if the _thick_ end be struck, even with a hammer, it will not break.

_The Magic Picture._

Take two level pieces of glass, (plate glass is the best,) about three inches long and four wide, exactly of the same size; lay one on the other, and leave a space between them by pasting a piece of card, or two or three small pieces of thick paper, at each corner.

Join these glasses together at the edges by a composition of lime slaked by exposure to the air, and white of an egg. Cover all the edges of these glasses with parchment or bladder, except at one end, which is to be left open to admit the following composition.

Dissolve, by a slow fire, six ounces of hogs'-lard, with half an ounce of white wax; to which you may add an ounce of clear linseed oil.

This must be poured in a liquid state, and before a fire, between the glasses, by the space left in the sides, and which you are then to close up. Wipe the glasses clean, and hold them before the fire, to see that the composition will not run out at any part.

Then fasten with gum a picture or print, painted on very thin paper, with its face to one of the glasses, and, if you like, you may fix the whole in a frame.

While the mixture between the glasses is cold, the picture will be quite concealed, but become transparent when held to the fire; and, as the composition cools, it will gradually disappear.

_Artificial Lightning._

Provide a tin tube that is larger at one end than it is at the other, and in which there are several holes. Fill this tube with powdered resin; and when it is shook over the flame of a torch, the reflection will produce the exact appearance of lightning.

_Artificial Thunder._

Mix two drachms of the filings of iron, with one ounce of concentrated spirit of vitriol, in a strong bottle that holds about a quarter of a pint; stop it close, and in a few minutes shake the bottle; then taking out the cork, put a lighted candle near its mouth, which should be a little inclined, and you will soon observe an inflammation arise from the bottle, attended with a loud explosion.

To guard against the danger of the bottle bursting, the best way would be to bury it in the ground, and apply the light to the mouth by means of a taper fastened to the end of a long stick.

_Another way._

Mix three ounces of saltpetre, two ounces of salt of tartar, and two ounces of sulphur; roll the mixture up into a ball, of which take a quantity, about the size of a hazel-nut, and, placing it in a ladle or shovel over the fire, the explosion will resemble a loud clap of thunder.

You will produce a much more violent commotion if you double or treble the quantity of the last experiment; suppose you put two or three ounces of the mixture into the shovel. For fear of accidents, it should not be done in the house, but by placing the shovel over a chafing-dish of very hot coals, in the open air, standing a great distance off.

Common prudence will dictate the necessity of using great care in the above experiments, as an accident will soon happen if a person does not get out of the way before the composition explodes.

_Money augmented by an Optical Illusion._

In a large drinking-glass of a conical shape, (small at the bottom and wide at the top,) put a shilling, and let the glass be half full of water; then place a plate on the top of it, and turn it quickly over, that the water may not escape. You will see on the plate a piece of coin of the size of half-a-crown; and a little higher up another the size of a shilling.

It will add to the amusement this experiment affords, by giving the glass to any one in company, (but who, of course, has not witnessed your operations,) and, desiring him to throw away the water, but save the pieces, he will not be a little surprised at finding only one.

_Three objects discernible only with both Eyes._

If you fix three pieces of paper against the wall of a room at equal distances, at the height of your eye, placing yourself directly before them, at a few yards' distance, and close your right eye, and look at them with your left, you will see only two of them, suppose the first and second; alter the position of your eye, and you will see the first and third: alter your position a second time, you will see the second and third, but never the whole three together; by which it appears, that a person who has only one eye can never see three objects placed in this position, nor all the parts of one object of the same extent, without altering his situation.

_To construct the Camera Obscura._

Make a circular hole in the shutter of a window, from whence there is a prospect of some distance; in this hole place a magnifying glass, either double or single, whose focus is at the distance of five or six feet; no light must enter the room but through this glass. At a distance from it, equal to its focus, place a very white pasteboard, (what is called a Bristol board, if you can procure one large enough, will answer extremely well;) this board must be two feet and a half long, and eighteen or twenty inches high, with a black border round it: bend the length of it inward to the form of part of a circle, whose diameter is equal to double the focal distance of the glass. Fix it on a frame of the same figure, and put it on a moveable foot, that it may be easily placed at that distance from the glass, where the objects appear to the greatest perfection. When it is thus placed, all the objects in front of the window will be painted on the paper in an inverted position, with the greatest regularity, and in the most natural colours. If you place a swing looking-glass outside the window, by turning it more or less, you will have on the paper all the objects on each side the window.

If, instead of placing the looking-glass outside the window, you place it in the room above the hole, (which must then be made near the top of the shutter,) you may have the representation on a paper placed horizontally on a table, and draw at your leisure all the objects reflected.

Observe, the best situation is directly north; and the best time of the day is noon.

_The Magnifying Reflector._

Let the rays of light that pass through the magnifying glass in the shutter be thrown on a large concave mirror, properly fixed in a frame. Then take a third strip of glass, and stick any small object on it; hold it in the intervening rays at a little more than the focal distance from the mirror, and you will see on the opposite wall, amidst the reflected rays, the image of that object, very large, and beautifully clear and bright.

_To tell by a Watch Dial the Hour when a Person intends to rise._

The person is told to set the hand of his watch at any hour he pleases, which hour he tells you; and you add in your mind 12 to it. You then desire him to count privately the number of that addition on the dial, commencing at the next hour to that at which he intends to rise, and including the hour at which he has placed the hand, which will give the answer: for example.

A intends to rise at 6, (this he conceals to himself;) he places the hand at 8, which he tells B, who, in his own mind, adds 12 to 8, which makes twenty. B then tells A to count twenty on the dial, beginning at the next hour to that at which he proposes to rise, which will be 5, and counting backwards, reckoning each hour as one, and including in his addition the number of the hour the hand is placed at, the addition will end at 6, which is the hour proposed; thus,

The hour the hand is placed at is 8
The next hour to that which A intends to rise at is 5, which
counts for 1
Count back the hours from 5, and reckon them at 1 each, there
will be 11 hours, viz., 4, 3, 2, 1, 12, 11, 10, 9, 8, 7, 6 11
----
Making 20

_A person having an even Number of Shillings in one Hand, and an odd Number in the other, to tell in which hand the odd or even Number is._

You desire the person to multiply the number in his right hand by an odd figure, and the number in his left by an even one; and tell you if the products, added together, be odd or even. If even, the even number is in the right hand; if odd, the even number is in the left. For instance,

I. Number in the right In the left hand _odd_ 7
hand is _even_ 18 Multiply by 2
Multiply by 3 ----
---- Product 14
Product 54 ----
Add the Product of
the left hand 14
----
Which produces a
total of 68

II. Number in the right In the left hand _even_ 18
hand is _odd_ 7 Multiply by 2
Multiply by 3 ----
---- Product 36
Product 21
Add the Product of
the left hand 36
----
Which produces a
total of 57

_Secret Correspondence._

To carry on a correspondence without the possibility of the meaning of the letter being detected, in case it should be opened by any other person, has employed the ingenuity of many. No method will be found more effectual for this purpose, or more easy, than the following.

Provide a piece of square card or pasteboard, and draw a circle on it, which circle is to be divided into 27 equal parts, in each of which parts must be written _one_ of the capital letters of the alphabet, and the &, as in the figure. Let the centre of this circle be blank. Then draw another circle, also divided into 27 equal parts, in each of which write one of the small letters of the alphabet, and the &. This circle must be cut round, and made exactly to fit the blank space in the centre of the large circle, and must run round a pivot or pin. The person with whom you correspond must have a similar dial, and at the beginning of your letter you must put the capital letter, and at the end the small letter, which answer to each other when you have fixed your dial.

Suppose what you wish to communicate is as follows:

_I am so watched I cannot see you as I promised; but I will
meet you to-morrow in the park, with the letters, &c._

You begin with the letter _T_, and end with the letter _m_, which shows how you have fixed the dial, and how your correspondent must fix his, that he may decipher your letter.

Then, for _I am_, you write _b uf_, and so of the rest, as follows.

_T b uf lh pumrvayx b rvugghm lyy rhn ul b ikhfblyx vnm b
pbee fyym rhn mh-fhkkhp bg may iukd pbma may eymmykl, tw.
m._

_Another Way._

Take two pieces of card, pasteboard, or stiff paper, through which you cut long squares at different distances. One of these you keep yourself, and the other you give to your correspondent. You lay the pasteboard on a paper, and, in the spaces cut out, write what you would have understood by him only; then fill the intermediate spaces with any words that will connect the whole together, and make a different sense. When he receives it, he lays his pasteboard over the whole, and those words which are between crotchets [ ] form the intelligence you wish to communicate. For example: suppose you want to express these word,

"_Don't trust Robert: I have found him a villain._"

"[Don't] fail to send my books. I [trust] they will be ready when [Robert] calls on you. [I have] heard that you have [found] your dog. I call [him a villain] who stole him." You may place a pasteboard of this kind three other ways--the bottom at top--the top at bottom, or by turning it over; but in this case you must previously apprize your correspondent, or he may not be able to decipher your meaning.

_Secret Correspondence by Music._

Form a circle like Fig. 2, divided into twenty-six parts, with a letter of the alphabet written in each. The interior of the circle is moveable, like that in Fig. 1, and the circumference is to be ruled like music-paper. Place in each division a note different in figure or position.

Within the musical lines place the three keys, and on the outer circle the figures to denote time. Then get a ruled paper, and place one of the keys (suppose _ge-re-sol_) against the time 2-4ths, at the beginning of the paper, which will inform your correspondent how to place his circle. You then copy the notes that answer to the letters of the words you intend to write, in the manner expressed above.

_The Magic Vessel._

On the bottom of a vessel, lay three pieces of money, the first at A, the second at B, and the third at C, Fig. 3. Then place a person at D, where he can see no farther into the vessel than E. You tell him, that by pouring water in the vessel you will make him see three different pieces of money; and bid him observe, that you do not convey any money in with the water. But be careful that you pour the water in very gently, or the pieces will move out of their places, and thereby destroy the experiment.

When the water rises up to F, the piece at A will be visible; when it reaches G, both A and B will be visible; and when it comes up to H, all three pieces will be visible.

_Artificial Earthquake and Volcano._

Grind an equal quantity of fresh iron filings with pure sulphur, till the whole be reduced to a fine powder. Be careful not to let any wet come near it. Then bury about thirty pounds of it a foot deep in the earth, and in about six or eight hours the ground will heave and swell, and shortly after send forth smoke and flames like a burning mountain. If the earth is raised in a conical shape, it will be no bad miniature resemblance of one of the burning mountains.

_Artificial Illuminations._

A very pleasing exhibition may be made with very little trouble or expense, in the following manner: Provide a box, which you fit up with architectural designs cut out on pasteboard; prick small holes in those parts of the building where you wish the illuminations to appear, observing, that in proportion to the perspective, the holes are to be made smaller; and on the near objects the holes are to be made larger. Behind these designs thus perforated, you fix a lamp or candle, but in such a manner that the reflection of the light shall only shine through the holes; then placing a light of just sufficient brilliance to show the design of the buildings before it, and making a hole for the sight at the front end of the box, you will have a very tolerable representation of illuminated buildings.

The best way of throwing the light in front, is to place an oiled paper before it, which will cast a mellow gleam over the scenery, and not diminish the effect of the illumination. This can be very easily planned, both not to obstruct the sight, nor be seen to disadvantage. The lights behind the picture should be very strong; and if a magnifying glass were placed in the sight hole, it would tend greatly to increase the effect. The box must be covered in, leaving an aperture for the smoke of the lights to pass through.

The above exhibition can only be shown at candle-light; but there is another way, by fixing small pieces of gold on the building, instead of drilling the holes; which gives something like the appearance of illumination, but by no means equal to the foregoing experiment.

N.B. It would be an improvement, if paper of various colours, rendered transparent by oil, were placed between the lights behind and the aperture in the buildings, as they would then resemble lamps of different colours.

_The Cameleon Spirit._

Put into a decanter volatile spirit, in which you have dissolved copper filings, and it will produce a fine blue. If the bottle be stopped, the colour will disappear; but when unstopped, it will return. This experiment may be often repeated.

_Invisible Ink._

Put litharge of lead into very strong vinegar, and let it stand twenty-four hours. Strain it off, and let it remain till quite settled; then put the liquor in a bottle.

You next dissolve orpiment in quick lime water, by setting the water in the sun for two or three days, turning it five or six times a-day. Keep the bottle containing this liquor well corked, as the vapour is highly pernicious if received into the mouth.

Write what you wish with a pen dipped in the first liquor; and, to make it visible, expose it to the vapour of the second liquor. If you wish them to disappear again, draw a sponge or pencil, dipped in aqua fortis, or spirit of nitre, over the paper; and if you wish them to re-appear, let the paper be quite dry, and then pass the solution of orpiment over it.

_Another._

Dissolve bismuth in nitrous acid. When the writing with this fluid is exposed to the vapour of liver of sulphur, it will become quite black.

_Another._

Dissolve green vitriol and a little nitrous acid in common water. Write your characters with a new pen.

Next infuse small Aleppo galls, slightly bruised in water. In two or three days, pour the liquor off.

By drawing a pencil dipped in this second solution over the characters written with the first, they will appear a beautiful black.

_Invisible Gold Ink._

Put as much gold in as small a quantity of aqua regia as will dissolve it, and dilute it with two or three times the quantity of distilled water.

Next dissolve, in a separate vessel, fine pewter in aqua regia, and when it is well impregnated, add an equal quantity of distilled water.

Write your characters with the first solution: let it dry in the shade. To make them visible, draw a pencil or sponge, dipped in the second solution, over the paper, and the characters will appear of a purple colour.

_Invisible Silver Ink._

Dissolve fine silver in aqua fortis; and after the dissolution, add some distilled water in the same manner as in the gold ink.

What is written with the above ink will remain invisible for three or four months, if kept from the air; but may be easily read in an hour, if exposed to the fire, air, or sun.

_Invisible Yellow Ink._

Steep marigold flowers seven or eight days in clear distilled vinegar. Press the flowers and strain the liquor, which is to be kept in a bottle well corked. If you would have it still more clear, add, when you use it, some pure water.

To make the characters visible, which you write with this ink, pass a sponge over the paper, dipped in the following solution:

Take a quantity of flowers of pansy, or the common violet, bruise them in a mortar with water, strain the liquor in a cloth, and keep it in a bottle.

_Invisible Red Ink._

To the pure spirit of vitriol or nitre, add eight times as much water.

Use the above solution of violets to make visible the characters written with this ink.

_Invisible Green Ink._

Dissolve salt of tartar, clean and dry, in a sufficient quantity of river water. Use the violet solution to render it visible.

_Another Invisible Green Ink._

Dissolve zaffre, in powder, in aqua regia, for twenty-four hours. Pour the liquor off, and the same quantity of common water, and keep it in a bottle well corked.

This ink will not be visible till exposed to the fire or the sun; and will again be invisible when it becomes cold.

_Invisible Violet Ink._

Express the juice of lemons, and keep it in a bottle well corked. Use the violet infusion to make the writing visible.

_Invisible Grey Ink._

Mix alum with lemon-juice. The letters written with this ink will be invisible till dipped in water.

* * * * *

We now present our readers with a variety of amusing experiments, which may be performed by the foregoing inks; and they will, probably, suggest others equally amusing and useful.

_A Secret Correspondence by means of Invisible Ink._

A person wishing to carry on a correspondence with another, and who is fearful of having his letter opened, or intercepted, can adopt the following plan:

Write any unimportant matter with common ink, and let the lines be very wide apart: then between these lines write the communication you wish to make, with any of the above invisible inks you can most readily procure.

Your correspondent is to be previously apprized of the method of making the characters visible: and writing in common ink will serve to lull the suspicions of those who might intercept the letter, and who, not finding any thing important in it, will either forward or keep it. In either case there can be no danger, as the writing will not be visible without the proper application.

_The Mysterious Writing._

Write on a piece of paper with common ink any question; then underneath it write the answer either in invisible silver ink, or the invisible green ink, made with zaffre and aqua regia, described in pages 24 and 25.

You give this paper to your friend, and tell him to place it against the wall, or on his dressing-table, keeping the door locked, that he may be sure no person has entered his room: he will next day find the answer written on it.

_The Restored Flowers._

Make a bouquet of artificial flowers; the leaves should be formed of parchment. Dip the roses in the red invisible ink, the jonquilles in the yellow, the pinks in the violet, and the leaves in the green ink. They will all appear white; and you show them to the company, observing, that you will restore them to their natural colours, and desiring any person to fix any private mark on them he pleases, that he may be sure there is no deception. You then, unperceived by the company, dip them in the revivifying liquor, used to make the yellow ink visible, described in page 24, and, drawing them gently out, that the liquor may drop, and the flowers have time to acquire their colours, you present them to the company, who will see, with surprise, that they each appear in their natural colours.

_Winter changed to Spring._

Take a print that represents winter, and colour those parts which should appear green, with the second green invisible ink, described in page 25; observing, of course, the usual rules of perspective, by making the near parts deeper in colour than the others. The other objects must be painted in their natural colours. Then put the print into a frame with a glass, and cover the back with a paper that is pasted only at its extremities.

When this print is exposed to a moderate fire, or the warm sun, the foliage, which appeared covered with snow, will change to a pleasing green; and if a yellow tint be thrown on the lighter parts before the invisible ink is drawn over it, this green will be of different shades. When it is exposed to the cold, it will again resume its first appearance of winter.

_The Silver Tree._

Dissolve an ounce of fine silver in three ounces of strong aqua fortis, in a glass bottle. When the silver is dissolved; pour the aqua fortis into another glass vessel, (a decanter will be best,) with seven or eight ounces of mercury, to which add a quart of common water; to the whole add your dissolved silver, and let it remain untouched.

In a few days the mercury will appear covered with a number of little branches of a silver colour. This appearance will increase for a month or two, and will remain after the mercury is entirely dissolved.

_The Lead Tree._

A more modern invention, and an easier method by far than the above, is the following:

To a piece of zinc fasten a wire, crooked in the form of the worm of a still; let the other end of the worm be thrust through a cork. You then pour spring water into a phial or decanter, to which you add a small quantity of sugar of lead; thrust the zinc into the bottle, and with the cork at the end of the wire fasten it up. In a few days the tree will begin to grow, and produce a most beautiful effect.

_To produce beautiful Fire-works in Miniature._

Put half a drachm of solid phosphorus into a large pint Florence flask; holding it slanting, that the phosphorus may not break the glass. Pour upon it a gill and a half of water, and place the whole over a tea-kettle lamp, or any common tin lamp, filled with spirit of wine. Light the wick, which should be almost half an inch from the flask; and as soon as the water is heated, streams of fire will issue from the water by starts, resembling sky-rockets; some particles will adhere to the sides of the glass representing stars; and will frequently display brilliant rays. These appearances will continue at times till the water begins to simmer, when immediately a curious aurora borealis begins, and gradually ascends, till it collects to a pointed flame; when it has continued half a minute, blow out the flame of the lamp, and the point that was formed will rush down, forming beautiful illuminated clouds of fire, rolling over each other for some time, which disappearing, a splendid hemisphere of stars presents itself: after waiting a minute or two, light the lamp again, and nearly the same phenomenon will be displayed as from the beginning. Let the repetition of lighting and blowing out the lamp be made for three or four times at least, that the stars may be increased. After the third or fourth time of blowing out the lamp, in a few minutes after the internal surface of the flask is dry, many of the stars will shoot with great splendour, from side to side, and some of them will fire off with brilliant rays; these appearances will continue several minutes. What remains in the flask will serve for the same experiment several times, and without adding any more water. Care should be taken, after the operation is over, to lay the flask and water in a cool, secure place.

_Artificial Rain and Hail._

Make a hollow cylinder of wood; let it be very thin at the sides, about eight or ten inches wide, and two or three feet diameter. Divide its inside into five equal parts, by boards of five or six inches wide, and let there be between them and the wooden circle, a space of about one-sixth of an inch. You are to place these boards obliquely. In this cylinder put four or five pounds of shot that will easily pass through the opening. When turned upside down, the noise of the shot going through the various partitions will resemble rain; and if you put large shot, it will produce the sound of hail.

_Illuminated Writing._

It is well known that if any words are written on a wall with solid phosphorus, the writing will appear as if on fire; but it is necessary to give this caution, lest accidents should occur. In using it, let a cup of water be always near you; and do not keep it more than a minute and a half in your hand, for fear the warmth of your hand should set it on fire. When you have written a few words with it, put the phosphorus into the cup of water, and let it stay a little to cool; then take it out, and write with it again.

_A Lamp that will burn Twelve Months without replenishing._

Take a stick of phosphorus, and put it into a large dry phial, not corked, and it will afford a light sufficient to discern any object in a room when held near it. The phials should be kept in a cool place, where there is no great current of air, and it will continue its luminous appearance for more than twelve months.

_Curious Transcolorations._

Put half a table-spoonful of syrup of violets and three table-spoonfuls of water into a glass; stir them well together with a stick, and put half the mixture into another glass. If you add a few drops of acid of vitriol into one of the glasses and stir it, it will be changed into a crimson; put a few drops of fixed alkali dissolved into the other glass, and when you stir it, it will change to green. If you drop slowly into the green liquor, from the side of the glass, a few drops of acid of vitriol, you will perceive crimson at the bottom, purple in the middle, and green at the top; and by adding a little fixed alkali dissolved, to the other glass, the same colours will appear in different order.

_Another._

If you put a tea-spoonful of a liquor composed of copper infused in acid of vitriol, into a glass, and add two or three table-spoonfuls of water to it, there will be no sensible colour produced; but if you add a little volatile alkali to it, and stir it, you will perceive a very beautiful blue colour. Add a little acid of vitriol, the colour will instantly disappear upon stirring it; and by adding a little fixed alkali dissolved, it will return again.

_Another._

Put half a tea-spoonful of a liquor composed of iron infused in acid of vitriol, into half a glass of water; and add a few drops of phlogisticated alkali, and a beautiful Prussian blue will appear.

_Curious Account of the Electric Effects of a Russian Climate._

Mr. AEpinus in a letter to Dr. Guthrie, relates the following phenomena, which took place in Russia, when a severe frost had continued for several weeks.

Mr. AEpinus was sent for to the palace to see an uncommon phenomenon. On going into the apartment of Prince Orloff, he found him at his toilet, and that every time his valet drew the comb through his hair, a strong crackling noise was heard; and on darkening the room, sparks were seen following the comb in great abundance, while the prince himself was so completely electrified, that strong sparks could be drawn from his hands and face; nay, he was even electrified when he was only powdered with a puff.

A few days after, he was witness to a more striking effect of the electric state of a Russian atmosphere. The Grand Duke of Russia sent for him one evening in the twilight, and told him, that having briskly drawn a flannel cover off a green damask chair in his bed-chamber, he was astonished at the appearance of a strong bright flame that followed; but considering it as an electrical appearance, he had tried to produce a similar illumination on different pieces of furniture, and could then show him a beautiful and surprising experiment. His highness threw himself on his bed, which was covered with a damask quilt, laced with gold; and, rubbing it with his hands in all directions, the young prince, who had then reached his twelfth year, appeared swimming in fire, as at every stroke flames arose all around him, darted to the gold-laced border, ran along it, and up to that of the bed, and even to the very top.

While he was showing this experiment, Prince Orloff came into the room, with a sable muff in his hand, and showed us, that by only whirling it five or six times round his head in the air, he could electrify himself so strongly, as to send out sparks from all the uncovered parts of his body.

_Astonishing Power of Steam._

If you put a small quantity of water into a tea-kettle, and place it on the fire, it will disappear in a short time, having escaped in the steam. But if its escape be prevented by stopping up the spout and crevices, it will force its way by bursting the vessel in which it was confined.

If the steam of boiling water be at liberty, the water never attains more than a certain degree of heat; but if confined in a close vessel, the additional fire not escaping, the power of the steam is increased, it re-acts upon the water, and raises the heat so much higher, that it would keep lead in a melting state; and so penetrating, that it would soften the marrow-bone of an ox, in a few minutes.

There is an instrument contrived for the foregoing purposes, called Papin's Digester, from the name of its inventor, and from its digestive powers on substances exposed to its action. It is a very strong vessel, made of copper, fitted with a thick close cover, and fastened down by several strong screws, so as to render it steam-tight in great degrees of heat. To render it safe, while being used, there is a valve on the cover, to let out the steam, when it is too violent; this valve is kept down by a steel-yard, with a weight moveable upon it, to regulate the degrees of the steam within.

The following account of an accident with one of these instruments, will give some idea of the great force of steam.

Mr. Papin (the inventor) having fixed all things right, and included about a pint of water, with two ounces of marrow-bone, he placed the vessel horizontally between the bars of the grate, about half-way into the fire. In three minutes he found it raised to a great heat, and perceiving the heat in a very short time become more raging, stepped to a side-table for an iron to take the digester out of the fire, when it suddenly burst with the explosion of a musket. It was heard at a considerable distance, and actually shook the house. The bottom of the vessel that was in the fire gave way; the blast of the expanded water blew all the coals out of the fire into the room, the remainder of the vessel flew across the room, and, hitting the leaf of an oak table, an inch thick, broke it all in pieces, and rebounded half the length of the room back again. He could not perceive the least sign of water, though he looked carefully for it; the fire was quite extinguished, and every coal black in an instant.

The following accident was attended with more fatal consequences.

A steam-engine was repairing at Chelsea, and, as the workmen were endeavouring to discover the defect, the boiler suddenly exploded, and a cloud of steam rushing out at the fracture, struck one of the men who was near it, like a blast of lightning, and killed him in a moment; when his companions endeavoured to take off his clothes, the flesh came off with them from the bones.

_Account of the Wonderful Effects of two immense Burning-Glasses._

Mr. de Tschirnhausen constructed a burning-glass, between three and four feet in diameter, and whose focus was rendered more powerful by a second one. This glass melted tiles, slates, pumice-stone, &c., in a moment; pitch, and all resins, were melted even under water; the ashes of vegetables, wood, and other matters, were converted into glass; indeed, it either melted, calcined, or dissipated into smoke, every thing applied to its focus.

Mr. Parker, of Fleet-street, made a burning-glass, three feet in diameter; it was formed of flint glass, and when on its frame, exposed a surface of 2 feet 8-1/2 inches to the solar rays. It had a small glass fitted to it, to converge the rays, and heighten the effect. The experiments made by it were more powerful and accurate than those performed by any other glass. The following is a brief epitome of its astonishing power.

--------------------------------------+-------+-------+
Substances melted, with their weight; |Weight | Time |
and the Time in Seconds, which | in | in |
they took in melting. |Grains.|Seconds|
--------------------------------------+-------+-------+
Pure gold | 20 | 4 |
---- silver | 20 | 3 |
---- copper | 33 | 20 |
---- platina | 10 | 3 |
Nickel | 16 | 3 |
A cube of bar-iron | 10 | 12 |
--------- cast-iron | 10 | 3 |
--------- steel | 10 | 12 |
Scoria of wrought-iron | 12 | 2 |
Kearsh | 10 | 3 |
Cauk, or terra ponderosa | 10 | 7 |
A topaz, or chrysolite | 3 | 45 |
An oriental emerald | 2 | 25 |
Crystal pebble | 7 | 6 |
White agate | 10 | 30 |
Oriental flint | 10 | 30 |
Rough cornelian | 10 | 75 |
Jasper | 10 | 25 |
Onyx | 10 | 20 |
Garnet | 10 | 17 |
White rhomboidal spar | 10 | 60 |
Zeolites | 10 | 23 |
Rotten-stone | 10 | 80 |
Common slate | 10 | 2 |
Asbestos | 10 | 10 |
Common lime-stone | 10 | 55 |
Pumice-stone | 10 | 24 |
Lava | 10 | 7 |
Volcanic clay | 10 | 60 |
Cornish moor-stone | 10 | 60 |
--------------------------------------+-------+-------+

_Fulminating Powder._

This powder is made by rubbing together, in a hot marble mortar, with a wooden pestle, three parts, by weight, of nitre, two of mild vegetable alkali, and one of flowers of sulphur, till the whole is accurately mixed. If a drachm of this powder be exposed to a gentle heat, in an iron ladle, till it melts, it will explode with a noise as loud as the report of a cannon.

_A more powerful fulminating Powder._

The most wonderful instance of chemical detonation is formed by the combination of volatile alkali with silver. Gunpowder, or fulminating gold, are not to be compared with this invention, and the great danger attending its manufacture prevents us from giving a methodical account of its preparation to our readers, particularly as it can be purchased, properly prepared, of the chemists.

The slightest agitation or friction is sufficient to cause its explosion. When it is once obtained, it can no longer be touched with safety. The falling of a few atoms of it, from a small height, produces an explosion; a drop of water falling on it has the same effect. No attempt, therefore, can be made to enclose it in a bottle, but it must be let alone in the capsule, wherein, by evaporation, it obtains this terrible property. To make this experiment with safety, no greater quantity than a grain of silver should be used; the last process of drying should be made in a metallic vessel, and the face of the operator defended by a mask with strong glass eyes.

_To make the Phosphorus Match Bottles._

Nothing more is necessary for this purpose, than to drop small pieces of dry phosphorus into a common phial; gently heat it till it melts; and then turn the bottle round, that it may adhere to the sides. The phial should be closely corked; and when used, a common brimstone match is to be introduced, and rubbed against the sides of the phial: this inflames the match when it is brought out of the bottle. Though there is no danger in phosphorus, till friction, or fire, is applied, yet persons cannot be too cautious in the use of it, as instances have been known of one of these bottles catching fire in the pocket, and very much endangering the person who carried it; likewise, if carelessly used, small particles are apt to get under the nails, or on the hand; and if, by accident, they are held to the fire, or rubbed together, a flame will presently kindle.

_To make a Ring suspend by a Thread, after the Thread has been burned._

Soak a piece of thread in urine, or common salt and water. Tie it to a ring, not larger than a wedding-ring. When you apply the flame of a candle to it, it will burn to ashes, but yet sustain the ring.

_To form Figures in relief on an Egg._

Design on the shell any figure or ornament you please, with melted tallow, or any other fat oily substance; then immerse the egg into very strong vinegar, and let it remain till the acid has corroded that part of the shell which is not covered with the greasy matter: those parts will then appear in relief, exactly as you have drawn them.

_To give a ghastly Appearance to Persons in a Room._

Dissolve salt in an infusion of saffron and spirits of wine. Dip some tow in this solution, and, having set fire to it, extinguish all other lights in the room.

_To change Blue to White._