With the coming of summer and a heady whiff of powder smoke in the air, America's pyrotechnists working like Santa's elves on Christmas Eve, predict that their newest fireworks will dazzle the senses as never before.
New insights from chemists and physicists are helping to shape a traditional craft with spectacular results. One new type of fireworks shell uses the firmament as a canvas for creating elaborate patterns painted in multicolored fire.
Some of these blazing tableaux might even include fiery letters forming entire words.
A new type of skyrocket propellant burns with a roar in brief, brilliant pulses of white light like those of a giant stroboscope. The flashes from the rocket's exhaust seem from the ground to freeze its ascending flight into a series of motionless snapshots.
Among the biggest pyrotechnic companies is Zambelli Internationale Manufacturing in New Castle, Pa., producing about 2,000 shows a year across the United States and abroad. It will produce shows in Maryland for July Fourth from Cumberland to Gibson Island.
Its biggest local event will be at the Inner Harbor at 9:30 tonight, where the explosives will be launched electronically and the show is computerized, said company salesman Victor Laurenza. He added that "pattern shells seem to be the rage" -- fireworks that explode in patterns like stars or hearts, choreographed to music.
Vitale Fireworks, also in New Castle, will be painting the skies over several Southern Maryland towns and Chestertown on the Eastern Shore with new displays that include butterflies, a chrysanthemum, patterned hearts and a circle surrounding a star.
The other major pyrotechnists locally work for Fireworks Productions in Glen Rock, Pa. -- a company boasting a new computer system to shoot its shows. It is scheduled to fire the rockets accompanying the Baltimore Symphony Orchestra at Baltimore County's Oregon Ridge Park at 8 tonight.
As millions of dollars go up in smoke during this summer's celebrations, some of the new pyrotechnic devices are expected to break records. A pyrotechnic "pinwheel," claimed to be the largest ever made, will be set off in August at an Idaho show.
Fireworks lovers are generally undaunted by risks of injury, although plastic surgeons predict that 11,000 Americans will require emergency hospital treatment for fireworks injuries this year.
Most of these casualties, organizers of public displays say, will result from careless or malicious handling of firecrackers, sparklers and other home fireworks by individuals, not from the stringently controlled displays mounted by professionals.
The leading pyrotechnists agree that the real artistry of fireworks is not in making big bangs but in painting pictures in fire. Still, the violent aspects of pyrotechnics contribute to an appeal that has lured many people into careers in chemistry, physics and space science.
As Dr. John A. Conkling, adjunct professor of chemistry at Washington College in Chestertown, wrote in an article in Scientific American:
"There is no question -- based on numerous conversations I have had with many researchers in many fields -- that many science careers were stimulated by early experiments in pyrotechnics."
Most pyrotechnics today, as throughout the last thousand years, rely heavily on "black" gunpowder, and pyrotechnics and warfare have evolved along parallel lines.
No one is certain who invented gunpowder, but many historians believe it originated in China in the ninth century, and it has been used to entertain and to kill people ever since.
The formula for black powder remains today what it was hundreds of years ago -- 75 parts by weight of potassium nitrate, 15 parts of charcoal and 10 parts of sulfur -- but the fireworks in which it is used have changed as radically as wheeled vehicles over centuries.
Black powder today merely propels the blazing displays into the sky; it no longer constitutes the show itself.
The glorious "peonies," "chrysanthemums," "fish," "palm trees," "triple-break salutes" and other fiery creations adorning modern festivities depend on far more complex chemistry than the burning of black powder.
Moreover, today's shows are fired into the air not by dangerous skyrockets but by reliable mortar guns essentially similar to those used in warfare.
The production of a rich blue fire, or flame, with a delicate violet or purple tint, is still one of the most difficult chemical challenges in pyrotechnics, and masters of the art judge each other by the quality of their blues.