Looking Back (And Looking Up) At That Essential July 4th Element: Fireworks

Jul 3, 2015

In a chemical engineering lab at Carnegie Mellon University, Matt Cline and William Alba stand in front of three rectangular packets made of tinfoil. An arm’s length away from the range hood, they use their thumbs to eclipse the flash they know is coming.

The packets contain a thermite — a pyrotechnic composition — a dash of flash powder and a metal salt. A heating element, similar to what makes a toaster toast, nestles in the grainy mix. Cline turns the power supply to full. Silence, and then WOOSH. FOOF! As the mélange combusts, a blast of heat rushes out from under the hood, accompanied by a flash of red light and the sound of Alba and Cline laughing.

That feeling, said Alba, is exactly what he and Cline are going for as they develop a new kind of firework. While they may expect a certain outcome in the lab, part of the joy of fireworks is unexpectedness, he said.

“You might hear them launch but the sky is still dark. And then all of a sudden, they blossom, they bloom,” Alba said.  

Humans have enjoyed the thrill of blowing things up since around 200 B.C. While fire-drying bamboo stalks on which they’d written transactions or stories, the Chinese discovered the stalks exploded if left too long. Between 600 and 900 A.D. Chinese alchemists created gunpowder and codified the happy accident of combustion: fireworks and modern warfare were born. Marco Polo brought fireworks back to Italy where the art of pyrotechnics evolved, said Dr. George Zambelli, Jr., chairman of Zambelli Fireworks Internationale, a fourth-generation family company based in New Castle.

“Italian alchemists started adding metal salts to the fireworks. Things like copper, which created the blue color, strontium the red, barium the green,” he said.  

Zambelli’s “doctor” title isn’t some sort of firework honorific — Zambelli is an ophthalmologist who said the family business allowed him to go to medical school. He started working at the plant when he was 12 years old.

“As I got older we’d get up early in the morning, load a firework truck, drive to a location, fire the display and go back to the firework plant," he said. "We used to sleep on the wooden tables fireworks were handcrafted on. We were like gypsies.”

New Castle, according to the U.S. Patent and Trademark Office, is the “Fireworks Capital of America.” Between 1890 and 1921 nearly 100,000 Italians migrated to western Pennsylvania. Many worked in the mills or mines, but some, like Zambelli’s grandfather Antonio, carried with them pyrotechnic “recipes” and built fireworks companies.

“I remember him coming back from fireworks displays and the smell of gunpowder on his clothes,” George Zambelli said.

Seventy miles southeast of where the Zambelli Company fills a string of barges with fireworks on the Ohio River, another kind of firework-maker — the exacting hobbyist — sits on his front porch, considering the thrill of controlled explosions.

“I think it’s man’s mastery over nature,” said Michael Uncapher. “You can mix this stuff together and it can create something really dangerous but at the same time beautiful.”

Uncapher started making fireworks in the early 2000s. His daughter Kate is his pyrotechnic sidekick. She studied chemical engineering at CMU with Matt Cline, largely in an effort to expand their knowledge.

“My dad would always ask me questions about the periodic table and what chemicals make what color and how does magnesium work and why does it burn so bright, and so I was like, well, I mean if we really want to try it then I should probably learn a lot more about it,” said Kate.  

At its most basic a firework is an oxidizer and a fuel, maybe a compound for color. The Uncaphers make it all. (The state of Pennsylvania, however, advises residents not to make their own fireworks.)

But after experimenting, "one thing leads to another,” said Michael. Like an annual July Fourth fireworks show that draws more than 400 spectators. When Kate’s dad announced at the start of the show that he saved scrap metal to trade in to buy firework materials, people took that as a cue, said Kate.

“We would have people pitch stuff in our yard: bags of aluminum, bags of cans. People I didn’t know and had never seen before in my life would throw stuff in our yard to help pay for fireworks,” she said. Michael laughed. “Transmissions, everything; it was crazy.”

The Uncaphers are currently on hiatus; it just got to be a little too much, they said. But Kate has a memory of her dad from the finale of their last show.

“My dad was up on the hill, and he always stands pretty close to the fireworks. He had his arms outstretched and was just laughing. That’s how I picture my dad, all the time.”  

On July 3, 1776, the day after John Adams voted for independence at the Continental Congress, he wrote to his wife Abigail that, forever more, the anniversary “ought to be solemnized with…Bonfires and Illuminations from one End of this Continent to the other. You will think me transported with Enthusiasm, but I am not…through all the Gloom I can see the Rays of ravishing Light and Glory.”

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