think of making a roman candle star like a marble; the Minie bullets and
the bolt-shot for our great guns are cylindrical, and far better fitted
than globes for straight and rapid flight. Why not adopt the same shape
for shells? I find cylindrical shells answer excellently. Have a
former, for a small one, 2-1/2 inches diameter, and about 6 inches long,
and with a handle like fig. 25. Roll a case upon it, 5 inches long, till
the outside gauges 2-3/4 inches, or a trifle more. Turn a wooden bottom,
3/4 of an inch thick; half of it a tenon to fit the inside of the case,
and half of it a flange, equal to the external diameter, a, fig. 95.
Glue this firmly in, and farther secure it with 4 inch French nails;
though, perhaps, this is not necessary. The top may be of the same
shape; half-an-inch thickness will be sufficient. A hole, an inch in
diameter, may be bored in it, with a centre-bit, to receive the fuse.
This fuse may be a cotton reel, with one of the flanges sawed off, and
the end filed slightly tapering, as fig. 105; the enveloping piece of
calico, or glazed lining, can then be passed to the bottom, as indicated
by the dotted lines; but a better way is to turn a piece of beech of the
shape of fig. 96, with a collar, to prevent its being blown through, and
a groove, by which the calico envelope can be tied. The length of the
fuse may be about 1-1/4 inch; charge it by putting in very little at a
time, and well mallet it. Pass a piece of naked match over the mouth of
the fuse, and down the sides of the cylinder, as indicated by the dotted
lines, fig. 95, having previously cut out a notch, at each corner, top
and bottom, e, e, e, e, to guide it in a straight line. Take a piece of
double-crown, about 20 inches long, and 7 broad; paste it all over, and
roll the cylinder in it, in such a way that it shall be flush at top,
and project at the bottom; press it round smooth with a cloth, or
sponge, till the leaders form a vein on each side. When dry, invert it;
put in the blowing powder; press the ends over, neatly, to form a
bottom; and cover the whole with a circular piece of pasted paper. A
shell of this size will hold forty gold rains, and a score or more blue
stars, which have a very pretty effect. The head and the fuse may be in
one solid piece, if preferred, as fig. 104; if the hole is longer than
1-1/4 inch, only 1-1/4 inch of it must be filled with fuse; a piece or
two of match may fill up the rest. The mortar for this shell should be
18 or 20 inches high, and 3 inches internal diameter. The shell, when
fitted up, will probably weigh about 14 or 15 ounces. The blowing
powder may be 2 or 2-1/2 ounces of F grain, according to the fit in the
mortar. The hole, in the wooden fuse, should be 3/8 of an inch diameter.
See that the match is everywhere carefully covered. A shell of this size
will be amply sufficient for amateur purposes. Perhaps it will be
advisable to try a fuse an inch long the first time; it will be better
that the shell should burst, while still ascending, than that it should
pitch. One or two trials are, in all cases, necessary; but as these
shells go a great height, they will bear a little longer fuse.
A cylinder holds half as much again as a shell of equal diameter;
consequently, when the depth is twice the diameter, which is the best
proportion, it holds three times as much as the spherical shell. If the
latter be 3 inches diameter, it may be represented by the numbers 3 × 3
× 3 = 27. If the cylinder be 3 inches diameter, and 6 inches deep, it
will be as 3 × 3 × 6 × 1-1/2 = 81. Practically, it will hold more,
especially of rains, or serpents, as they pack better in a cylinder.
The spheroidal shell, like the spherical, is, also, 2/3 of its
circumscribing cylinder.
Putting D, the diameter of a spherical; and d, that of a cylindrical
shell, the length being always double the diameter; then D³ = 3 d³.
Required the diameter of a cylindrical shell, that shall be of equal
capacity with a spherical shell, of 12 inches diameter.
12³ = 1728; 1728 ÷ 3 = 576 = d³, and
∛576 = 8·3 = d.
so the cylindrical shell will be 8-3/10 inches diameter, and 16-3/5
inches long.
The same computation is more readily effected by multiplying the
diameter by ∛(1/3);
∛(1/3) = ∛(9/27) = 1/3 ∛9 = ·693.
Then ·693 × 12 = 8·3, as before.
Shells, for war purposes, are both spherical and cylindrical; the latter
are, sometimes, built up in pieces, which dovetail into each other; they
are, then, set in a cylinder, and melted lead is poured round to bind
the pieces together. For lighting up the country, to discover the
movements of the enemy on a dark night, shells are fired, containing
strong calico parachutes, carrying blue lights. Magnesium lights are, of
course, more effective.
The bottoms and tops of the cylindrical shells, previously described,
may be turned out of a plank of wood: elm, ash, common mahogany, or good
yellow deal; and, as many amateurs who possess a lathe, know of no
contrivance for holding flat pieces of board without making a hole
through them, the following plan may be adopted. On the screw-chuck,
fig. 102, screw a piece of deal board, previously sawn nearly circular,
and as large as the lathe will take: let it be of a thickness to
entirely hide the point of the screw; turn it to a circle; and over the
face of it, with a blacklead pencil, while it is revolving, make a
number of concentric circles, as in fig. 103. Also, cross it with two
straight lines, passing through the centre, at right angles to each
other. Cut the wood, intended for the bottom of the shell, into a
square; make a hole at each corner, and with 4 screws, or 4 French
nails, screw or nail it on the face: the concentric circles, and the two
diametrical lines crossing them, will act as guides to centre it. I have
thus been able to cut into a circle, in the lathe, so thin a substance
as a piece of writing paper. It may be held on with 4 tin-tacks, or a
touch of gum.
A nest of 6 or 9 little shells, each containing a separate colour,
rains, serpents, crackers, &c., may be enclosed in a large shell: the
fuse of these may be a very short piece of a squib-case, with the string
wound 7 or 8 times round the choke, to form a flange, to prevent its
blowing through.
Cylindrical shells should, of course, be filled before the head is glued
in; this can have the fuse previously fixed in, and ready.
_ASTEROID ROCKETS._
These differ from other rockets only in the head, which contains a
parachute for floating a coloured case, attached to the strings. The
parachute is best formed of silk, or alpaca; it may also be made of
black glazed lining, or of tissue paper, carefully rubbed, till the
stiffness is removed. The colour should be dark, that it may be
invisible. If of silk, or alpaca, the parachute may be 20 inches square,
with 4 strings attached to the corners; or it may be made of 6
triangular pieces, sewed together, like an umbrella. If of tissue paper,
the paper may be 6/8 of a circle, or 6/8 of an octagon, as fig. 97. The
tissue paper must be strengthened with a piece of crochet cotton,
running round the edge, as shown by the dotted lines, fig. 101. It is
simply laid on, and the paper snipped at each corner, with the scissors,
pasted, and turned back. The radius of the circle may be 15 inches.
For the lance, or colour, roll the case of 3 thicknesses of writing
paper, on a 5/8 former: it may be 2-1/2 or 3 inches long, and pasted all
over. Turn a little wooden pulley, a, fig. 98, of a diameter to nearly
fit the cylindrical head of the rocket; a hole in the centre of this
pulley receives the colour; round the pulley, in the groove, lay a piece
of chenille, fig. 100; twist the wires of the chenille 2 or 3 times
together, and cut off flush. To charge the lance, set it on a flat
surface, and drive in a film of meal powder, or shell fuse; then 1/3 of
an inch of crimson star composition; 1/3 of an inch of green, &c., till
nearly full; stop the end with plaster of paris, pressed in flat, with a
knife. Paste a strip of paper round the mouth, so as to overhang not
more than 1/8 of an inch; lay in two short pieces of match, one across
the other, and tuck in, or press down, the pasted overhanging edges;
this will keep the match from dropping out. Glue the pulley on, about
midway of the case; envelope the end b with a bit of glazed lining. Take
a piece of string, fig. 99; bring the ends together, and tie in a knot.
Insert the knot in the envelope, and tie round above it, as at fig. 100,
leaving the loop out, to which to attach the strings of the parachute.
Let the strings be 2 feet long: fasten them to the loop; gather them
together; wind them round the colour, above the pulley; fold the
parachute neatly, and bring the edges down over the strings, nearly to
reach the pulley: this will keep the parachute a little open, and help
it to expand. Both the tissue paper and the glazed lining should be well
rubbed, to get the stiffness out of them. To ascertain how a parachute
will act, the learner can take the colour case, and stop one end with
plaster, fill up with sand, and stop the other end with plaster. Fire it
in the day time. Silk, alpaca, and glazed lining parachutes I can vouch
for; tissue paper I have never tried, but am told it answers if it has
not remained folded so long as to get set.
Between the top of the rocket and the mouth of the colour is to be a
little pad of grain powder. Make a little square or circular paper bag
with double-crown, and having put in the grain, and made the joining
secure, smear both sides in the usual way, and sift dry meal over. If
the rocket is to be fired at home, the parachute may be put into a long
cylindrical paper bag, and left quite open at the top; but if intended
to be carried to a distance, a thin bung may be put in at top, or a
piece of turned wood: or a thin piece of paper may be pasted on it. In
this case, be careful that it does not get stuck to the parachute.
Instead of the cylindrical head and the chenilled pulley, the head, fig.
39, may be used; and the protecting power from the fire to the strings
supplied by putting a quantity of bran or sawdust. The cone must be held
on, with not more than two thicknesses of double-crown.
_COMPOUND FIREWORKS._
Fig. 108. A triangular: 3 wheel cases and a case colour, at a. These
cases are tied either to a hexagonal piece of deal board, or to three
spokes, radiating from a nave. The colour is sometimes tied to a nail,
driven in to receive it; or, it may be fixed on to a little peg. The peg
is shown, by the side, at b. It is turned with a tenon, c; this tenon is
glued in a hole, bored in the spoke; the part b may be half an inch in
length; through it bore a small hole; charge the case colour on a foot,
that enters the case half-an-inch; this void fits on to the peg b;
pierce the case, through the hole in the peg, with a bradawl; push a bit
of binding wire through, and twist. This is a far better way than tying
it to a nail, as it cannot drop off. If the colour gets blown off, as it
often does when tied, the piece is half spoilt. The colour may either
stand at right angles, so as to face the spectator; or it may be fixed
so as to lie in a plane with the wheel cases, very slightly sloping
upwards; the mouth of the colour should point the same way as the mouth
of the cases; if it were placed in the opposite direction, it would
meet the current of air, be blown back upon itself, and burn the case
rapidly. With respect to the wheel cases, it is obvious that the mouths
must all point in the same direction; the slightest consideration would
suggest this; it is necessary, therefore, to have some certain rule of
proceeding, so as to avoid mistakes. Now supposing, for the mere sake of
illustration, if you had a case in your hand, it were to take fire, you
would naturally wish the fire to be directed _from_ you. Let this, then,
be the guide. You are about to tie the cases on a wheel. Sit, to do so;
take the wheel between your knees: place a case upon it, with the choke
end _from_ you; tie, near the choke, also near the end; turn the wheel,
place another case upon it, choke end _from_ you; and so forth. Without
this certain way of proceeding, you would be very embarrassed with the
12 cases on fig. 112; but, by attending to it, not the slightest
difficulty will be experienced. Some of the cases will point obliquely
upwards; some downwards; but they will all point _from_ you. In the end
of the last case, as at x, fig. 108, put a little dry clay, to prevent
a stray spark igniting it, and tie the envelope; or, tuck in the
envelope, like as with an ounce of tobacco. Avoid every source of
failure. Even the knots of the strings, with which the cases are tied
on, are apt to come undone; they should either be touched with a dab of
glue, or have a piece of paper pasted over them.
Fig. 109. A double triangular: 3 cases tied to the spokes; 3 to the
previous 3. Double triangular frames are also made, with 6 spokes, on a
long nave, 3 behind 3.
Fig. 110. A vertical wheel, illuminated. This is a wheel, with spokes,
and a rim, or felly. The wooden hoops of the toyshops will furnish the
latter. The illumination, as it is called, is made by lances, nailed
with 1/2 inch Flemish tacks to the nave. The lances should be of
different colours, but they ought, as nearly as possible, to keep time
with each other. To effect this, it is necessary previously to adjust
them; thus. Charge a number of cases, exactly two inches long, with
different colours; use the same scoop to all, and give each the same
number of blows, that they may be rammed as uniformly as possible.
Fasten a string to the end of a leaden bullet, and tie a loop at the
other end of the string. Let the length from the top of the bullet to
the top of the loop be 39 inches. Suspend this from something, and set
it swinging. Light the lances, one after another, and count the number
of oscillations each endures. Keep a list of these, and write against
them 10, 12, &c., or 5 per inch, 6 per inch. The bullet will indicate
seconds, with the length of string recommended; and it matters not
whether you give it a start of 6 inches, or 12 inches; for, if it goes
twice as far, it goes twice as fast, so that the swings isochronise; the
inestimable discovery of Galileo, which led to the invention of the
pendulum. In order that the lances may be nailed on, they should be
charged upside down, and left with 1/2 an inch vacancy; they can then be
pinched flat, to receive the tack. Scrape out a little from the other
end, and prime with very slightly damped meal.
Fig. 111. A rainbow wheel. This is a vertical wheel, generally with 3
colours, as drawn; the tail of the second, or mouth of the third, lights
a; the mouth of the fourth, b and c; but any arrangement may be made.
Place the colours, red, green, blue, at different distances from the
centre, so as to form rings, equidistant, when burning. Suppose the
spoke 12 inches long; place the colours at 3, 6, and 9 inches from the
centre. It receives its name from its resemblance to the rainbow.
Fig. 112. A caprice, or furilona, according to the number of the cases.
A caprice, from the capricious manner in which it turns, up, down, and
round about, now this way, now that. A furilona, possibly, from the fury
with which it plays, when 4 cases are burning together, at the end:
though some call it a fruiloni, said to be from the name of its
inventor. A furilona and caprice wheel are much the same; the former,
generally, has fewer cases on it than the latter. A coloured gerbe,
placed on the top, is very effective; or, it may have a mine, or
jack-in-the-box. The cases are to be placed so that some of them play
horizontally, some obliquely upwards, some obliquely downwards; the
spokes, which are concave at the end, are glued in, so as to determine
the slope of the cases. If there are 10 cases, they may be fired thus,
h, u, d, hud, hudp; that is, 1 horizontal, 1 up, 1 down; 3 at once,
horizontal, up, down; 4 at once, horizontal, up, down, perpendicular. If
13 cases, thus: h, u, d, hu, hd, ud, hudp. While tying the cases on the
frame, it should be on a short wire, held perpendicularly in a vice, or
block of wood; properly, the wire should be tapering, so that the frame
should bite, when dropped on; the tapering will allow it to be turned
round, easily, by slightly lifting it. Let the leaders be drawn
straight, and not left dangling in curves, nor crossing each other.
There must be _enough_ match, but there ought to be no more. Look well
to the mouths and tails of the cases; it is best to put a piece of
pasted paper over each, for as the piece dashes round with great
violence, if a stray spark falls on any composition filtering out, the
whole is spoilt.
Fig. 113. A horizontal wheel, with mine and roman candles; the cases on
the wheel are to be tied so that some play horizontally; some, obliquely
upwards; some, obliquely downwards. To make a case play thus, tie it on
the wheel, across the middle of the case; this being done, turn the
mouth upwards or downwards, and tie it again, making the strings cross
the previous ones, so as to form a letter X.
Fig. 114. A turning sun: two concentric hoops nailed to spokes, or a
frame; the cases lying on the hoops, slope; 3 or 4 may light at once;
the spokes carry triangular, or vertical wheels; at the centre is a
double triangular, or larger vertical.
Fig. 115. A rayonant star piece: a wheel with six spokes; at the end of
each spoke, two fixed cases, forming a V, the alternate spokes carrying
saxons; at the centre, a double triangular, half-way between the
triangles and the saxons, six five-pointed stars. A very beautiful
piece.
Fig. 116. A chequer-piece: a true-lover's-knot in the middle, 16 fixed
cases, 4 on each side the true-lover's-knot; and 4 saxons at the
extremities. The fires cross, and chequer into squares.
Fig. 117. A scroll wheel: six or more cases on the wheel, to play in
pairs; lances arranged on cane or hooping to form a scroll as
indicated.
Fig. 118. A pyramidical piece: a scroll wheel in the middle; five
horizontal wheels, or triangulars, at intervals, as represented by the
rings; brilliant fixed cases playing obliquely upwards: at the bottom
may be a row of cases playing downwards; these form what is called a
cascade. Gerbes make the most effective cascades, but they require to be
placed at a great height from the ground, if containing iron: the coke
grains will be found suited for 8 or 10 feet.
Fig. 119. A spiral wheel: six cases on a horizontal wheel; lances
arranged in a spiral, on cane, or hooping.
Fig. 120. A true-lover's-knot: six 6/8 wheel cases, playing in pairs;
three saxons, one carrying a blue; one, a green; one, a crimson colour.
Light at a; this leader blows across, and lights the opposite starting
case. The tail of this case lights the saxons: the ends of the saxons at
c, c, c, before enveloping them, are to be smeared with meal; the end,
b, is also to be smeared with wetted meal, to insure the ignition of the
leader. This is a most beautiful piece: the colours, on the saxons, form
loops, and represent, in a slight degree, the compound motions of the
moon and planets, with regard to the earth. The centres of the saxons
are carried round in a circle, like the earth in her orbit; the colours
on the saxons revolve round the flying centres, like the moon round the
earth. The wheel must not be less than 3 feet diameter.
Fig. 121. A revolving globe. This is, also, a most beautiful piece. The
bottom is a horizontal wheel, carrying a strong half hoop, a b c; a
skeleton globe, formed with hoops, is suspended in this. This globe is
driven by cases placed upon it, round a hoop, crossing the other hoops,
at right angles, like the equator, at right angles to the meridians. The
meridional hoops are covered with lances, white or coloured. The globe
revolves vertically, while the wheel below turns it horizontally; the
compound motion produces a peculiar oblique tumbling convolution,
exceedingly perplexing to spectators, ignorant of its construction.
Instead of a globe, the top piece may be a revolving cylinder.
Fig. 122. A mine. This is a cylindrical case, containing serpents. The
bottom of the mine should be a circular piece of wood, glued in. On it,
place a circular bag, containing F grain powder. The bag is made with
two circular pieces of paper, one half-an-inch diameter larger than the
other; lay the small one on the top of the large one: paste, or gum, the
exposed rim of the bottom piece, and bend it up, and press it down on
the small or top piece, all round, leaving a part through which to put
the powder; when dry, put in the powder, and stop up the hole. Put it
into the mine, smear it with the brush, dipped into meal paste, in the
usual way; and, with a pepper-box, shake in a little dry meal. Take a
fixed case, charged; envelop it, so that the paper projects about an
inch at the bottom: take a piece of squib-case, the same length as the
serpents; put through it a piece of match, long enough to protrude at
the top, half-an-inch, and to bend over, to form a hook: tie this in the
envelope of the fixed case. Fill the mine with serpents, naked primed
mouth downwards: with the scissors, or a pair of pliers, draw out the
middle serpent; put in the matched squib-case; hold the fixed case
upright, in the mine, and ram pieces of torn paper tight round it, to
offer resistance, and cause the serpents to be blown higher. To adjust
the blowing powder in the bag, use the following formula, I denoting the
diameter in inches.
I x 2I = drams.
Required the quantity of powder for a mine 1-1/2 inch diameter.
1-1/2 x 3 = 4-1/2 drams = 1/4 oz.
For 1-3/4 inches?--1-3/4 x 3-1/2 = 7/4 x 7/2 = 49/8 = 6-1/8 drams = 3/8
oz.
For 2 inches?--2 x 4 = 8 drams = 1/2 oz.
For 2-1/2 inches?--2-1/2 x 5 = 12-1/2 drams = 3/4 oz.
For 3 inches?--3 x 6 = 18 drams = 1-1/8 oz.
It is by no means necessary to be exact; but the formula will serve as a
guide.
Fig. 123. A jack-in-the-box. This is a case formed on a square prism of
wood. The paper is to be pasted all over, but as it cannot be rolled, it
must be folded over, one side at a time, and rubbed smooth with a
tooth-brush handle, or pressed with the fingers. The bottom may be
formed by bending in, to a right angle, two opposite sides, and pressing
them flat; then, upon them, the two remaining sides, like packets of
cocoa, &c. Or a square piece of wood may be glued in for a bottom. The
same blowing charge as for mines.
Fig. 124. A devil-among-the-tailors: a mixture of crackers and serpents;
a roman candle in the middle, having its bottom stopped with shell fuse,
instead of plaster of paris: 3, or 4, or any number of roman candles, at
regular distances, round the outside: these are to be tied with string,
and a strip of pasted paper fastened round.
Fig. 125. A line-rocket: two rockets tied to a piece of roman candle
case, head to tail: that is, one rocket tied in one direction, the
other, in the reverse. This simply runs up and down a line.
Fig. 126. A pigeon frame (of which fig. 127 is a cross section) may be
made by taking a piece of deal, or alder, say 6 inches long, and 1-1/2
inch square: bore a hole through the length to receive the line upon
which it is to run; plane off the corners, lengthwise, and channel them
with a gouge, to form 4 semi-cylinders for the rockets to lie in: in the
middle glue 4 spokes, each about 4 inches long; and round the spokes
nail a wheel. A piece of cane makes good spokes, light and strong. Tie
on the frame, lying in the channels, four 6/8 rockets, two pointing one
way; two, the other: the clay or plaster of paris, in these rockets, is
not to have a hole through it, as usual, but to remain perfectly closed.
On the wheel, tie four 5/8 wheel cases, charged with wheel case fuse,
No. 1 or No. 10. Leader it thus: touchpaper the mouth of one wheel case.
From the tail of this first wheel case, carry two leaders; one to the
next wheel case, and one to the rocket whose mouth is nearest: the tail
of the second wheel case lights the third wheel case and second rocket;
and so on. A long clothes line must be stretched tight for this to run
along; it should start 3 or 4 yards, at least, from the post to which
the line is tied: and the rope should be so long that the first rocket
could not carry it to the end; otherwise the leaders are apt to snap and
spoil the piece. Towards the end, as the piece gets lighter, it will run
the whole length of the rope, without injury. It is necessary to
indicate the first, or starting rocket, by some means; a piece of red
paper may be pasted round the mouth; or, an inch or two of string may
be tied to it; or the match may be bent and tied so as to project an
inch or two longer than the others. On fixing it on the line, in the
dark, you can then feel which is the starting rocket, and place its
mouth _towards_ the starting post, without hesitation. Of course the
pigeon runs away in the opposite direction.
Fig. 128. A pigeon-house, made with lances; this may be fixed in a
central position, and have 4 lines running from it: east, west, north,
and south. As soon as the lances are well alight, start the pigeons.
This is not necessary for amateurs. One pigeon is sufficient, without
any pigeon-house.
The piece, fired at the Crystal Palace, termed a comet, is a combination
of the pigeon, fig. 126, and the turning sun, fig. 114. Construct a
pigeon frame, with two hoops, one at each end; to these hoops, attach
brilliant cases, or gerbes, placed obliquely: point the mouths of all
the rockets and gerbes in the same direction. The whole of the cases may
be lit at once; or a short case may fire the rockets after the piece has
partly descended the line, by its own weight. The line, at the Crystal
Palace, is stretched from the top of the northern tower to the ground.
Fig. 129. A double guilloché, or windmill piece. This represents two
windmills, turning in opposite directions; and imitates the engine
turning, on the backs of watches.
Fig. 130. A five-pointed star. This has been already described.
It is desirable, sometimes, to convey the fire from a movable or
rotating piece, to a fixed, or second rotating piece, which is effected
thus. A leader, a, fig. 131, comes from the tail of the last case of the
first rotating piece. This leader is tied, in one or more places, to one
of the spokes of the wheel, and to the nave; and is left protruding at
b. A tin box, or a bit of a mine case, d e f g, is attached to the
fixed, or second movable piece in such a manner, as to surround, but
stand clear of, the end of the match, b, as it revolves, with the wheel.
A hole is made at c, and the end of a leader, from the second piece,
brought through it. The inside surface of the box, d e f g, is smeared
with meal-paste. When the leader catches at a, it blows through to b;
this lights the smeared surface of the box; the flash communicates the
fire to c, and this carries it where desired.