power to restore themselves. A hop-plant, twisting round a stick,
directs its course from south to west, as the sun does. Untwist it,
and tie it in the opposite direction, it dies. Leave it loose in the
wrong direction, it recovers its natural direction in a single night.
Twist a branch of a tree so as to invert its leaves, and fix it in
that position; if left in any degree loose, it untwists itself
gradually, till the leaves be restored to their natural position. What
better can an animal do for its welfare? A root of a tree meeting with
a ditch in its progress, is laid open to the air; what follows? It
alters its course like a rational being, dips into the ground,
surrounds the ditch, rises on the opposite side of its wonted distance
from the surface, and then proceeds in its original direction. Lay a
wet sponge near a root exposed to the air; the root will direct its
course to the sponge; change the place of the sponge, the root varies
its direction. Thrust a pole into the ground at a moderate distance
from a climbing plant; the plant directs its course to the pole, lays
hold of it, and rises on its natural height. A honeysuckle proceeds in
its course, till it be too long for supporting its weight, and then
strengthens itself by shooting into a spiral. If it meet with another
plant of the same kind, they coalesce for mutual support; the one
screwing to the right, the other to the left. If a honeysuckle twig
meet with a dead branch, it screws from the right to the left. The
claspers of briony shoot into the spiral, and lay hold of whatever
comes in their way, for support. If, after completing a spiral of
three rounds, they meet with nothing, they try again, by altering
their course.
_Flowers curiously affected by the Sun and the Weather._
The petals of many flowers expand in the sun, but contract all night,
or on the approach of rain; after the seeds are fecundated the petals
no longer contract. All the trefoil may serve as a barometer to the
husbandman; they always contract their leaves on an impending storm.
_Easy Method of obtaining Flowers of different Colours from the same
Stem._
Scoop out the pith from a small twig of elder, and having split it
lengthwise, fill each of the parts with small seeds that produce
flowers of different colours, but that blossom nearly at the same
time. Surround them with earth; and then tying together the two bits
of wood, plant the whole in a pot filled with earth, properly
prepared.
_A Luminous Bottle, which will show the Hour on a Watch in the Dark._
Throw a bit of phosphorus, of the size of a pea, into a long glass
phial, and pour boiling oil carefully over it, till the phial is
one-third filled. The phial must be carefully corked, and when used
should be unstopped, to admit the external air, and closed again. The
empty space of the phial will then appear luminous, and give as much
light as an ordinary lamp. Each time that the light disappears, on
removing the stopper it will instantly re-appear. In cold weather the
bottle should be warmed in the hands before the stopper is removed. A
phial thus prepared may be used every night for six months.
_To make Luminous Writing in the Dark._
Fix a small piece of solid phosphorus in a quill, and write with it
upon paper; if the paper be carried into a dark room, the writing will
appear beautifully luminous.
_The Sublimated Tree._
Into a large glass jar inverted upon a flat brick tile, and containing
near its top a branch of fresh rosemary, or any other such shrub,
moistened with water, introduce a flat thick piece of heated iron, on
which place some gum benzoin, in gross powder. The benzoin, in
consequence of the heat, will be separated, and ascend in white fumes,
which will at length condense, and form a most beautiful appearance
upon the leaves of the vegetable.
_Easy and curious Methods of foretelling Rainy or Fine Weather._
If a line be made of good whipcord, that is well dried, and a plummet
affixed to the end of it, and then hung against a wainscot, and a line
drawn under it, exactly where the plummet reaches, in very moderate
weather it will be found to rise above it before rain, and to sink
below when the weather is likely to become fair. But the best
instrument of all, is a good pair of scales, in one of which let there
be a brass weight of a pound, and in the other a pound of salt, or of
saltpetre, well dried; a stand being placed under the scale, so as to
hinder it falling too low. When it is inclined to rain, the salt will
swell, and sink the scale: when the weather is growing fair, the brass
weight will regain its ascendancy.
_Contrivance for a Watch Lamp, perfectly safe, which will show the
Hour of the Night, without any trouble, to a person lying in Bed._
It consists of a stand, with three claws, the pillar of which is made
hollow, for the purpose of receiving a water candlestick of an inch
diameter. On the top of the pillar, by means of two hinges and a bolt,
is fixed on a small proportionate table, a box of six sides, lined
with brass, tin, or any shining metal, nine inches deep, and six
inches in diameter. In the centre of one of these sides is fixed a
lens, double convex, of at least three inches and a half diameter. The
centre of the side directly opposite to the lens is perforated so as
to receive the dial-plate of the watch, the body of which is confined
on the outside, by means of a hollow slide. When the box is lighted by
a common watch-light, the figures are magnified nearly to the size of
those of an ordinary clock.
_Curious Experiment with a Tulip._
The bulb of a tulip in every respect resembles buds, except in their
being produced under ground, and include the leaves and flower in
miniature, which are to be expanded in the ensuing spring. By
cautiously cutting in the early spring, through the concentric coats
of a tulip root, longitudinally from the top to the base, and taking
them off successively, the whole flower of the next summer's tulip is
beautifully seen by the naked eye, with its petals, pistal, and
stamina.
_The Travelling of Sound experimentally proved._
There is probably no substance which is not in some measure a
conductor of sound; but sound is much enfeebled by passing from one
medium to another. If a man, stopping one of his ears with his finger,
stop the other also by pressing it against the end of a long stick,
and a watch be applied to the opposite end of the stick, or a piece of
timber, be it ever so long, the beating of the watch will be
distinctly heard; whereas, in the usual way, it can scarcely be heard
at the distance of fifteen or eighteen feet. The same effect will take
place if he stops both his ears with his hands, and rest his teeth,
his temple, or the gristly part of one of his ears against the end of
a stick. Instead of a watch, a gentle scratch may be made at one end
of a pole or rod, and the person who keeps his ear in close contact
with the other end of the pole, will hear it very plainly. Thus,
persons who are dull of hearing, may, by applying their teeth to some
part of a harpsichord, or other sounding body, hear the sound much
better than otherwise.
If a person tie a strip of flannel about a yard long, round a poker,
then press with his thumbs and fingers the ends of the flannel into
his ears, while he swings the poker against an iron fender, he will
hear a sound very like that of a large church bell.
_To produce Metallic Lead from the Powder._
Take one ounce of red lead, and half a drachm of charcoal in powder,
incorporate them well in a mortar, and then fill the bowl of a
tobacco-pipe with the mixture. Submit it to an intense heat, in a
common fire, and when melted, pour it out upon a slab, and the result
will be metallic lead completely revived.
_To diversify the Colours of Flowers._
Fill a vessel of what size or shape you please, with good rich earth,
which has been dried and sifted in the sun, then plant in the same a
slip or branch of a plant bearing a white flower, (for such only can
be tinged,) and use no other water to water it with, but such as is
tinged with red, if you desire red flowers; with blue, if blue
flowers, &c. With this coloured water, water the plant twice a day,
morning and evening, and remove it into the house at night, so that it
drink not of the morning or evening dew for three weeks. You will then
experience, that it will produce flowers, not altogether tinctured
with that colour wherewith you watered it, but partly with that, and
partly with the natural.
_How far Sound travels in a Minute._
However it may be with regard to the theories of sound, experience has
taught us, that it travels at about the rate of 1142 feet in a second,
or nearly thirteen miles in a minute. The method of calculating its
progress is easily made known: when a gun is discharged at a distance,
we see the fire long before we hear the sound; if, then, we know the
distance of the place, and know the time of the interval between our
first seeing the fire, and then hearing the report, this will show us
exactly the time the sound has been travelling to us. For instance, if
the gun be discharged a mile off, the moment the flash is seen I take
a watch and count the seconds till I hear the sound; the number of
seconds is the time the sound has been travelling a mile.
_Easy Method of making a Rain Gauge._
A very simple rain gauge, and one which will answer all practical
purposes, consists of a copper funnel the area of whose opening is
exactly ten square inches: this funnel is fixed in a bottle, and the
quantity of rain caught is ascertained by multiplying the weight in
ounces by 173, which gives the depth in inches and parts of an inch.
In fixing these gauges, care must be taken that the rain may have free
access to them: hence the tops of buildings are usually the best
places. When the quantities of rain collected in them at different
places are compared, the instruments ought to be fixed at the same
heights above the ground at both places, because at different heights
the quantities are always different, even at the same place.
_To make beautiful Transparent coloured Water._
The following liquors, which are coloured, being mixed, produce
colours very different from their own. The yellow tincture of
saffron, and the red tincture of roses, when mixed, produce a green.
Blue tincture of violets, and brown spirit of sulphur, produce a
crimson. Red tincture of roses, and brown spirits of hartshorn, make a
blue. Blue tincture of violets, and blue solution of copper, give a
violet colour. Blue tincture of cyanus, and blue spirit of
sal-ammoniac coloured, make green. Blue solution of Hungarian vitriol,
and brown ley of potash, make yellow. Blue solution of Hungarian
vitriol, and red tincture of roses, make black; and blue tincture of
cyanus, and green solution of copper, produce red.
_Curious Experiment on Rays of Light._
That the rays of light flow in all directions from different bodies,
without interrupting one another, is plain from the following
experiment:--Make a little hole in a thin plate of metal, and set the
plate upright on a table, facing a row of lighted candles standing
near together; then place a sheet of paper or pasteboard at a little
distance from the other side of the plate; and the rays of all the
candles, flowing through the hole, will form as many specks of light
on the paper as there are candles before the plate; each speck as
distinct and large as if there were only one candle to cast one speck;
which shows that the rays do not obstruct each other in their motions,
although they all cross in the same hole.
_The Power of Water._
Let a strong small iron tube of twenty feet in height be inserted into
the bung-hole of a cask, and the aperture round so strongly closed,
that it shall be water-tight; pour water into the cask till it is
full, through the pipe; also continue filling the pipe till the cask
bursts, which will be when the water is within a foot of the top of
the tube. In this experiment the water, on bursting the vessel, will
fly about with considerable violence.
_The Pressure of Water._
The pressure of water may be known to every one who will only take the
trouble to look at the cock of a water-butt when turned: if the tub or
cistern be full, the water runs with much greater velocity through
the cock, and a vessel will be filled from it in a shorter time than
when it is only half-full, although the cock, in both cases, is
equally replete with the fluid during the time the vessel is filling.
From this also is understood, how a hole or leak, near the keel of a
ship, admits the water much quicker, and with greater violence, than
one of the same size near what the mariners call the water's edge.
_Refraction of Light._
In the middle of an empty basin put a piece of money, and then retire
from it till the edge of the basin hides the piece from your sight:
then keep your head steady, let another person fill the basin gently
with water; as the water rises in the basin the money will come in
view; and when of a sufficient height in the basin, the whole of the
piece will be in sight.
_Wonderful Nature of Lightning._
If two persons, standing in a room, looking different ways, and a loud
clap of thunder, accompanied with zigzag lightning, happen, they will
both distinctly see the flash at the same time; not only the
illumination, but the very form of the lightning itself, and every
angle it makes in its course will be as distinctly perceptible, as
though they had both looked directly at the cloud from whence it
proceeded. If a person happened at that time to be looking on a book,
or other object, which he held in his hand, he would distinctly see
the form of the lightning between him and the object at which he
looked. This property seems peculiar to lightning, as it does not
apply to any other kind of fire whatever.
_To show that the White of Eggs contains an Alkali._
Add to a wine-glass half full of tincture of red cabbage a small
quantity of the white of an egg, either in a liquid state or rendered
concrete by boiling. The tincture will lose its blue colour and become
changed to green, because the white of the egg contains soda.
_Two Inodorous Bodies become very Pungent and Odorous by Mixture._
When equal parts of muriate of ammonia and unslaked lime, both
substances destitute of odour, are intimately blended together in a
mortar, a very pungent gas (ammonia) becomes evolved.
_Interesting Experiment for the Microscope._
The embryo grain of wheat, at the time of blossoming, being carefully
taken out of the husk, will be found to have a small downy tuft at its
extremity, which, when viewed in a microscope, greatly resembles the
branches of thorn, spreading archwise, in opposite directions. By
expanding a few of the grains, and selecting the most perfect, a very
pretty microscopic object will be obtained for preservation.
_The Travelling of Light._
Light travels at the rate of a hundred and fifty thousand miles in a
single second; and it is seven minutes in passing from the sun to the
earth, which is nearly a distance of seventy millions of miles. Such
is the rapidity with which these rays dart themselves forward that a
journey they thus perform in less than eight minutes, a ball from the
mouth of a cannon would not complete in several weeks! But the
minuteness of the particles of light are still several degrees beyond
their velocity; and they are therefore harmless, because so very
small. A ray of light is nothing more than a constant stream of minute
parts, still flowing from the luminary, so inconceivably little, that
a candle in a single second of time, has been said to diffuse several
hundreds of millions more particles of light, than there could be
grains in the whole earth, if it were entirely one heap of sand. The
sun furnishes them, and the stars also, without appearing in the least
to consume, by granting us the supply. Its light is diffused in a wide
sphere, and seems inexhaustible.
_Calculation of the Mass of Water contained in the Sea._
If we would have an idea of the enormous quantity of water which the
sea contains, let us suppose a common and general depth of the ocean;
by computing it at only 200 fathoms, or the tenth part of a mile, we
shall see that there is sufficient water to cover the whole globe to
the height of 503 feet of water; and if we were to reduce this water
into one mass, we should find that it forms a globe of more than sixty
thousand miles diameter.
_Different Degrees of Heat imbibed from the Sun's Rays by Cloths of
different Colours._
Walk but a quarter of an hour in your garden, when the sun shines,
with a part of your dress white, and a part black; then apply your
hand to them alternately, and you will find a very great difference in
their warmth. The black will be quite hot to the touch, and the white
still cool.
Try to fire paper with a burning-glass; if it be white, you will not
easily burn it; but if you bring the focus to a black spot, or upon
letters, written or printed, the paper will immediately be on fire
under the letters.
Thus, fullers and dyers find black cloths, of equal thickness with
white ones, and hung out equally wet, dry in the sun much sooner than
the white, being more readily heated by the sun's rays. It is the same
before a fire, the heat of which sooner penetrates black stockings
than white ones, and so is apt sooner to burn a man's shins. Also beer
much sooner warms in a black mug set before the fire than a white one,
or in a bright silver tankard. Take a number of little square pieces
of cloth from a tailor's pattern card, of various colours; say black,
deep blue, lighter blue, green, purple, red, yellow, white, and other
colours, or shades of colours; lay them all out upon the snow in a
bright sun-shiny morning; in a few hours, the black being warmed most
by the sun will be sunk so low as to be below the stroke of the sun's
rays; the dark blue almost as low; the lighter blue not quite so much
as the dark; the other colours less, as they are lighter; and the
quite white remain on the surface of the snow, as it will not have
entered it at all.
_Alternate Illusion._
With a convex lens of about an inch focus, look attentively at a
silver seal, on which a cipher is engraved. It will at first appear
cut in, as to the naked eye; but if you continue to observe it some
time, without changing your situation, it will seem to be in relief,
and the lights and shades will appear the same as they did before. If
you regard it with the same attention still longer, it will again
appear to be engraved: and so on alternately.
If you look off the seal for a few moments, when you view it again,
instead of seeing it, as at first, engraved, it will appear in relief.
If, while you are turned towards the light, you suddenly incline the
seal, while you continue to regard it, those parts that seemed to be
engraved will immediately appear in relief: and if, when you are
regarding these seemingly prominent parts, you turn yourself so that
the light may fall on the right hand, you will see the shadows on the
same side from whence the light comes, which will appear not a little
extraordinary. In like manner the shadows will appear on the left, if
the light fall on that side. If instead of a seal you look at a piece
of money, these alterations will not be visible, in whatever situation
you place yourself.
_Alarum._
Against the wall of a room, near the ceiling, fix a wheel of twelve or
eighteen inches diameter; on the rim of which place a number of bells
in tune, and, if you please, of different sizes. To the axis of this
wheel there should be fixed a fly to regulate its motion; and round
the circumference there must be wound a rope, to the end of which is
hung a weight.
Near to the wheel let a stand be fixed, on which is an upright piece
that holds a balance or moveable lever, on one end of which rests the
weight just mentioned; and to the other end must hang an inverted
hollow cone, or funnel, the aperture of which is very small. This cone
must be graduated on the inside, that the sand put in may answer to
the number of hours it is to run. Against the upright piece, on the
side next the cone, there must be fixed a check, to prevent it from
descending. This stand, together with the wheel, may be enclosed in a
case, and so contrived, as to be moved from one room to another with
very little trouble.
It is evident, from the construction of this machine, that when a
certain quantity of the sand is run out, the weight will descend, and
put the wheel in motion, which motion will continue till the weight
comes to the ground. If the wheel be required to continue longer in
motion, two or more pulleys may be added, over which the rope may run.
_Musical Cascade._
Where there is a natural cascade, near the lower stream, but not in
it, let there be placed a large wheel, equal to the breadth of the
cascade: the diameter of this wheel, for about a foot from each end,
must be much less than that of the middle part; and all the water from
the cascade must be made to fall on the ends. The water that falls on
the wheel may pass through pipes, so that part of it may be made
occasionally to pass over or fall short of the wheel, as you would
have the time of the music quicker or slower. The remaining part of
the wheel, which is to be kept free from the water, must consist of
bars, on which are placed stops that strike against the bells: these
stops must likewise be moveable. It is evident from the construction
of this machine, that the water falling on the floats at the end of
the wheel, will make the stops, which are adapted to different tunes,
strike the notes of those tunes on the respective bells. Two or three
sets of bells may here be placed on the same line, when the cascade is
sufficiently wide.
Where there is not a natural cascade, one may be artificially
constructed, by raising part of the ground, wherever there is a
descent of water; whether it be a stream that supplies a reservoir or
fountain, or serves domestic uses; or if it be refuse water that has
already served some other purpose.
_Writing on Glass by the Rays of the Sun._
Dissolve chalk in aqua fortis, to the consistence of milk, and add to
that a strong solution of silver. Keep this liquor in a glass decanter
well stopped. Then cut out from a paper the letters you would have
appear, and paste the paper on the decanter, which you are to place in
the sun, in such a manner that its rays may pass through the spaces
cut out of the paper, and fall on the surface of the liquor. The part
of the glass through which the rays pass will turn black, and that
under the paper will remain white. You must observe not to move the
bottle during the time of the operation.
_To produce the Appearance of a Flower from its Ashes._
Make a tin box, with a cover that takes off. Let this box be supported
by a pedestal of the same metal, and on which there is a little door.
In the front of this box is to be a glass.
In a groove, at a small distance from this glass, place a double
glass, made in the same manner as described in p. 13, (_Magic
Picture._) Between the front and back glasses place a small upright
tin tube, supported by a cross piece. Let there be also a small
chafing-dish placed in the pedestal. The box is to be opened behind.
You privately place a flower in the tin tube, but not so near the
front glass as to be in the least degree visible, and presenting one
that resembles it to any person, desire him to burn it on the coals in
a chafing-dish.
You then strew some powder over the coals, which may be supposed to
aid the ashes in producing the flower; and put the chafing-dish in the
pedestal under the box. As the heat by degrees melts the composition
between the glasses, the flower will gradually appear, but when the
chafing-dish is taken away, and the powder of the ashes is supposed to
be removed, the flower soon disappears.
You may present several flowers, and let the person choose any one of
them. In this case, while he is burning the flower, you fetch the box
from another apartment, and at the same time put in a corresponding
flower, which will make the experiment still more surprising.
_Imitative Fire-works._
Take a paper that is blacked on both sides, or instead of black, the
paper may be coloured on each side with a deep blue, which will be
still better for such as are to be seen through transparent papers. It
must be of a proper size for the figure you intend to exhibit. In this
paper cut out with a penknife several spaces, and with a piercer make
a number of holes, rather long than round, and at no regular distance
from each other.