Spur Fire
This fire is the most beautiful of any composition yet known. As it
requires great trouble to bring it to perfection, particular care must
be paid to the following instructions. They are made generally in
cases about six inches long, but not driven very hard.
CHARGE. lb. oz. CHARGE. lb. oz.
Saltpetre 4 0 } { Saltpetre 1 0
Sulphur 2 0 } or
{ Sulphur 0 8
Lamp-black 1 8 } { Lamp-black 4 quarts.
This composition is very difficult to mix. The saltpetre and brimstone
must be first sifted together, and then put into a marble mortar, and
the lamp-black with them, which you work down by degrees with a wooden
pestle, till all the ingredients appear of one colour, which will be
something greyish, but very near black; then drive a little into a
case for trial, and fire it in a dark place; and if the sparks, which
are called stars or pinks, come out in clusters, and afterwards spread
well without any other sparks, it is a sign of its being good,
otherwise, not; for if any drossy sparks appear, and the stars not
full, it is then not mixed enough; but if the pinks are very small,
and soon break, it is a sign that you have rubbed it too much.
This mixture, when rubbed too much, will be too fierce, and hardly
show any stars; and, on the contrary, when not mixed enough, will be
too weak, and throw out an obscure smoke, and lumps of dross, without
any stars. The reason of this charge being called the spur fire is,
because the sparks it yields have a great resemblance to the rowel of
a spur, from whence it takes its name. As the beauty of this
composition cannot be seen at so great a distance as brilliant fire,
it has a better effect in a room than in the open air, and may be
fired in a chamber without any danger; it is of so innocent a nature,
that, although an improper phrase, it may be called a cold fire; and
so extraordinary is the fire produced from this composition, that, if
well made, the sparks will not burn a handkerchief when held in the
midst of them; you may hold them in your hand while burning, with as
much safety as a candle; and if you put your hand within a foot of the
case, you will feel the sparks fall like drops of rain.