|
Even though China invented the fireworks, Europe surpassed them in pyrotechnic development
in the 14th century, which coincides with the time the gun was invented. Shot and gunpowder
for military use was made by skilled tradesmen, later called firemakers, who also made
fireworks for peace or victory celebrations. During the Renaissance, two European schools of
pyrotechnic thought emerged: one in Italy and the other at Nuremberg, Germany.
The Italian school of pyrotechnics emphasized elaborate fireworks, and the German school
stressed scientific advancement. Both schools added significantly to further development
of pyrotechnics, and by the mid-17th century fireworks were used for entertainment on an
unprecedented scale in Europe, being popular even at resorts and public gardens.
In the mid-19th century fireworks became popular in the United States.
A black powder comprised of potassium nitrate, sulfur, and charcoal—the first modern
high-energy composition that today we call gunpowder. The Greeks used this mixture
(and a similar one that generated flames and dense fumes when ignited) almost exclusively
in military applications—in both sea and land battles—and changed the face of military science.
It is thought that thousands of years ago, some smarty in China (or perhaps India) discovered
that this potassium nitrate, sulfur, and charcoal mixture burned with a bright orange flash
and plume of smoke upon ignition—perfect for scaring away evil spirits.
They also found out that placing the powder in a paper tube would noisily explode upon
ignition, a precursor to firecrackers. They also discovered that if the powder were arranged
in a thin line, it would quickly burn along that trail, a precursor to fuses. And finally,
if the powder were compressed in a tube with a sealed end, the hot gases from the ignited
powder would propel the tube happily skyward, a precursor to fireworks.
The next major advance took place in the 1780s. Claude Berthollet, the great French chemist,
prepared potassium chlorate (KClO3) to use as a replacement for potassium nitrate.
Although KClO3 had a propensity for causing deadly explosions when blended with sulfur, metal
powders, and ammonium salts, it did add color to the pyrotechnician’s arsenal.
Pyrotechnic technology really, um, took off in the 19th century. Pyrotechnicians started
putting metal chlorides in the fireworks to produce a dazzling array of color. Barium
chloride produces a brilliant green, strontium a vivid red, and copper compounds a
whitish-blue. There were some setbacks though. Beautifully named chemicals like Paris green
(copper acetoarsenite), calomel (mercurous chloride), and realgar (arsenic sulfide),
proved to be hazardous to the pyrotechnician’s health.
And aside from tinkering with visual effects (the star, the sparkler, etc.) fireworks have
stayed pretty much the same until recently.
In the last couple of decades, fireworks designers have used a magnesium-aluminum alloy
know as magnalium in their fireworks, which brightens and deepens the colors, almost to
fluorescence—which I’ve heard not only frightens away the evil spirits, but attracts the
good ones.
|