The Chemistry of Powder and Explosives - Sciencemadness Dot Org

SPARKLERS 117
is shaped by a motion of the worker's other hand into the form
of a trough which is then filled with a narrow train of powder,
and, by another motion of the hand, the fingers being moistened,
is twisted into the finished fuse; Figure 42. This is set aside to
dry and is cut into lengths for use in the crackers. The fuses
of the finished crackers are braided or pleated together, Figure
43, making the crackers into bunches, and the bunches are
wrapped and labeled, Figure 44.
Flash Cracker Composition
Chinese firecrackers and American machine-made salutes are
loaded with compositions which contain powdered aluminum
and potassium chlorate or perchlorate. They produce a bright
flash and an extremely sharp report when they explode. The compositions
listed below are typical. The first four in the table have
been used in Chinese firecrackers. For the last four the author
is indebted to Allen F. Clark.
Potassium perchlorate . . . . 6 1 7 ..
Potassium chlorate 2 3 7 . . .
Potassium nitrate .. . 5
Barium nitrate . 3 1 . 4
Aluminum (fine powder) 1 4 2 1 5 1 5 2
Sulfur . 1 3 3 2 .. 1 . 1
Antimony sulfide 1 . . .
The compositions which contain barium nitrate produce a green
flash, the others a white one. All of them burn with great rapidity
in the open It is debatable whether the phenomenon of the
burning is not really an explosion, or would be one if the material
were not allowed to scatter while being burned. With the
exception of the third and the last, they are all fulminating explosives
when confined. All the mixtures which contain sulfur
along with chlorate or perchlorate can be exploded on an iron
anvil by a moderately strong blow with an iron hammer.
Sparklers
Snowball sparklers (Allen F. Clark) are made from:
Potassium nitrate 64
Barium nitrate 30
Sulfur 16
Charcoal dust 16
Antimony sulfide 16
Fine aluminum pow Jer . 9
Dextrin . . 16