The Chemistry of Powder and Explosives - Sciencemadness Dot Org

STARS 81
the space between the star and the wall of the tube is partly filled
with candle comp. When the three materials have been introduced,
they are rammed tightly into place. Then gunpowder, a
star, and candle comp again are loaded into the tube and rammed
down, and so on until the tube is charged. Damp candle comp,
with a piece of black match leading to it and into it, is loaded at
the top, pressed tightly into place, and allowed to dry. When a
Roman candle is lighted, the candle comp begins to burn and to
throw out a fountain of sparks. The fire soon reaches the star,
ignites it, and flashes along the side of the star to light the gunpowder
which blows the burning star, like a projectile, out of the
tube.
Stars
Stars are pellets of combustible material. Those which contain
neither aluminum nor magnesium nor Paris green have nothing
in their appearance to suggest even remotely the magic which is
in them. They are, however, the principal cause of the beauty of
aerial pyrotechnic displays.
The components of star composition are mixed intimately and
dampened uniformly with some solution which contains a binder,
perhaps with gum-arabic water, perhaps with water alone if the
composition contains dextrin, perhaps with alcohol if it contains
shellac. Several different methods are used for forming the stars.
To make cut stars, the damp mixture is spread out in a shallow
pan, pressed down evenly, cut into cubes, say x /4 to % inch on
the side, allowed to dry, and broken apart. Because of their
corners, cut stars take fire very readily and are well suited for
use in rockets and small aerial bombshells. Cylindrical stars are
preferred for Roman candles.
For the preparation of a small number of stars, a star pump is
a convenient instrument. This consists of a brass tube with a
plunger which slides within it. The plunger has a handle and, on
its side, a peg which works within a slot in the side of the tube—
in such manner that it may be fixed in position to leave at the
open end of the tube a space equal to the size of the star which
it is desired to make. This space is then tightly packed with the
damp mixture; the plunger is turned so that the peg may move
through the longitudinal slot, and the handle is pushed to eject
the star.