COMPOUND FIREWORKS (_continued_)
Ruggieri’s next class (fireworks turning vertically) includes the
following:
1. Revolving Suns. These are merely vertical wheels; he appears to use
this term for the more ambitious pieces of this kind.
2. Vertical Wheels. He illustrates a vertical wheel exactly as made
to-day under that name. It has, however, been elaborated by the
addition of colour cases on the spokes and centre, as rosette and
rainbow wheels; also by the application of saxons to the spokes, as
saxon wheels.
He also shows the triangle wheel, consisting of three spokes with
grooved ends to receive the cases whose sides form the sides of an
equilateral triangle. This has been further developed into the double
triangle wheel, with two sets of spokes placed one set behind the
other. In all the wheels in this class the cases fire in succession,
not as in the case of the sun—simultaneously.
Windmills he illustrates as flat bars pivoted in the centre with three
cases at either end fired in succession. There also were three, four,
and up to eight-armed windmills of the same kind. The nearest device to
these of modern times is the chromatrope, the simplest form of which
has two bars with a gerb at either end so set as to revolve them in
opposite directions, the front one carrying two saxons. This piece,
which is of comparatively simple design, gives an extraordinarily fine
effect by the intersections of the various streams of fire.
The chromatrope has been developed and enlarged until for important
display work quite elaborate pieces are fired under this name.
Lancework of geometric form is used on the bars or spokes, and the
intersection of these, forming ever-changing geometrical designs, adds
greatly to the effect of the intersection of the fire.
This effect is the basis of the Guilloché, a somewhat elaborate piece
which falls in Ruggieri’s third class. It consisted of six wheels
placed one behind the other in pairs of graduated size; the two
smallest—which fired first—had six cases, the next eight, and the
largest forty-eight, and was twenty feet in diameter.
The next described is the Salamandre, a piece which, on a large scale,
is still occasionally fired at the Crystal Palace. It shows a snake
in pursuit of a butterfly which it seems to overtake but never quite
catches. The mechanism is an endless chain of wooden links running in
and out between eight sprocket wheels, arranged in octagon formation.
About half the length of the chain is made out and lanced to represent
the snake, and a lancework butterfly is situated in the centre of the
other half.
Ruggieri claims that his father fired this piece and the guilloché in
1739 at Versailles.
The other pieces mentioned in this section are too elaborate for
description in the space available, but are interesting as showing
the use of the helix and spiral as applied to wheels and cones, as
secondary elements of larger pieces.
The modern designer of pyrotechnic pieces has great advantage over the
earlier practitioners in that he has available an infinitely larger
range of colour and other composition. It is often possible to get a
much-enhanced result with less cases giving more or varied effects as
opposed to a larger number of cases of similar effects, which, in an
attempt to produce a lavish show of fire, end in confusion.
His fourth division begins with the “Caprice simple”; this is the
modern horizontal wheel. This wheel is similar in arrangement to the
vertical above-mentioned, except that its cases are arranged so that
the first plays horizontally in the plane of the wheel, the next at an
angle downwards, and the third upwards. This succession is repeated
with the remaining three cases. In addition, the horizontal wheel has
either a mine which is lit from the last case, or Roman candles and
mine, at the centre playing upwards. The second form is arranged so
that the Romans are fired simultaneously with the fourth case and the
mine from the last.
The wheel given by Ruggieri has a gerb in the centre. He explains that
Caprice is a generic name applied to all horizontal wheels which vary
the direction of the fire when revolving. However, at the present time
the name Caprice is only applied to a wheel with three tiers of three
cases, each similar in appearance to three single triangle wheels
superimposed at distances about equal to their diameter, the grooves in
the end of the spokes being so arranged as to vary the direction of the
fire. The cases are led up in the following order—one case horizontal,
one up, one down, one horizontal, two cases one up and one down, four
cases in each direction and one vertical. For a compact piece this is
one of the most effective made.
A similar piece is the Furiloni Wheel, which has, however, two tiers of
three cases each.
Jones describes a furiloni wheel which is more elaborate, having
twenty-five cases. His method of leading would, however, not be so
effective as the modern wheels of this type. The cases used for these
wheels are charged with a steel mixing formerly known as brilliant fire.
He mentions two other devices—Caprices petans and Caprices des pâtés.
The first of these was a modification of the piece formerly used in
this country as the balloon wheel. It consisted of a solid wheel round
which are a series of mines which discharged in succession as each
turning case lit. The second was similar but more elaborate, having
rockets as well as mines, and was a variation of the rocket wheel.
In his description of the Girandole, he explains that it is composed of
two horizontal wheels one above the other. This is the form taken by
the rocket wheel as fired in this country which, as we have seen, was
known as the girandole wheel. Ruggieri, however, appears not to have
used rockets on his girandole.
The last device he mentions in this class is the Spirali, which
consisted of a framework in the form of a cone, round which was wound a
spiral of cane fitted with lances.
A very effective piece, not mentioned by Ruggieri, is the revolving
fountain; it consists of a wood centre bored to turn on a vertical
spindle. The centre has two spokes fitted with gerbs for turning, and
has playing vertically a large gerb and Roman candles. The turning
gerbs play tangentially and slightly upwards.
Jones describes a similar device under the name of “illuminated spiral
wheel”; also two other horizontal pieces—the spirali and the plural
wheels, which approximate to the furiloni and caprice wheels of the
present day.
The spiral and helix are much used in larger devices, and the use of
modern lancework and colour has greatly added to their effect.
Ruggieri’s next division deals with built-up lancework pieces such as
the globe, which it was thought worthy of separate mention in his time,
but to-day is included with many devices of this nature too numerous to
mention, forming, as they do, a large proportion of the mechanical and
other pieces used in display work.
[Illustration: A Display ready for Firing, Dresden, September 1st,
1899. Firework Portraits of the King and Queen of Saxony on the
right, Bismarck second from the left.]
He then deals with tourbillions and table wheels. The latter
consisted of a circular table with a central pivot, round which is free
to revolve a bar which forms the axle of a wheel, the hub of which runs
on the edge of the table. When the wheel is turned, the hub running on
the edge of the table moves it forward in a circular path round the
pivot. This principle is applied to similar and more elaborate devices.
The name tourbillions, as before mentioned, is by other writers
differently applied.
The section dealing with cut-out and transparent devices is of little
interest. These devices were an attempt to give variety from the
monotonous repetition of turning cases and gerbs. To-day the use of
colour cases, lances, a much-enlarged range of fountain and similar
compositions, including aluminium and other brilliant fires, has
obviated the employment of effects which cannot be rightly considered
as pyrotechnic.
The moving and stationary pieces considered in this and preceding
chapters give a good general idea of the firing methods in compound
fireworks. As we have already noted, the difference of designs and
effects at the present time is infinite, so that it would be impossible
in a work of the present size to give anything approaching a complete
survey of what has been accomplished. But it is hoped that enough has
been said to give the reader some idea of the methods adopted and the
lines upon which the modern pyrotechnist works.