31. The formulas for crimson, rose, blue, and purple Roman-candle stars
are the same as given for rocket stars, and must be moistened with the
liquid directed in my last paper as proper for each one.
You have now formulas for making brilliant, white, golden, green,
crimson, rose, blue, and purple stars.
ROMAN-CANDLE STARS (To Make).
32. In order to make the stars, moisten the compositions _very
slightly_. The mould in which these stars are shaped is a brass tube of
a size proportioned to the size of the Roman-candle case, and is
generally about one-sixteenth of an inch smaller in its inner diameter
than the case. The drift with which the composition is pressed into the
tube is made of boxwood or metal, and fits easily into the tubular
mould. At one of its ends there is a wire point. Place the end having
the point in the mould as far as it will go. You will find a space left
at the end of the mould unoccupied by the drift. Press this empty end of
the tube into the slightly-moistened composition until it is filled by
it, so that the drift, being driven down upon the composition, will
compress it into a firm cylindrical mass, into the centre of which the
wire point projects. Figures 35, 37, and 39, represent the mould, drift,
and finished star. When the star is thus formed in the mould the drift
must be reversed, and its long plain end inserted, and the star pushed
out. The object of making the star hollow is that it may dry and harden
perfectly in its centre. If heat is employed to dry the stars, they have
a tendency to harden outside rapidly, and thereby an impervious coating
is formed, through which the inner moisture cannot evaporate. This
difficulty is obviated by leaving a hole in the centre of the star, and
this hole is made of use for another important purpose—namely, _the
priming_ of the star.
My plan for insuring the ignition of the stars is, as far as I know,
peculiar to myself, and I have the satisfaction of knowing that it has
never failed me. Some pyrotechnists recommend the smearing of the star
with a very combustible paste; this plan, however, must to some extent
injure the colour of the star. I simply place a little piece of
quick-match into the hole in the star, and allow it to project about a
quarter of an inch above. By this means even slowly-combustible stars
are ignited, and almost every chance of failure is avoided.
This priming, however, should not be done until the stars are to be put
into the cases—at all events, till they are perfectly dry. Their drying
may be effected naturally out-of-doors in the summer, when a very few
hours’ exposure in the sun will render them thoroughly hard and fit for
use. In the winter time, however, artificial heat should be used. I
always find that the more rapidly, _up to a certain point_, these stars
are hardened, the better they keep. Nothing, however, will be gained by
hurrying them through this process, except a danger of their exploding.
Place them carefully, and not touching one another, in a tin box having
a lid, and let this box remain at such a distance before a fire that it
can become thoroughly warm, _not hot_, till the stars are thought hard
enough to be put away. They should be kept, when dry, in
closely-stoppered bottles in a dry place. Each star will weigh, at
least, thirty grains.