I did a quick Google to double-check this. The following is a quote from goodbyemag or some such site.
Most circus historians credit the Englishman George Farini with the invention of the human cannonball. In 1877 he presented the exotic and beautiful Zazel as a human cannonball at the Royal Aquarium in Westminster. Zazel subsequently toured with P.T. Barnum’s circus in America. But Farini’s patented, spring-loaded cannon was unreliable and lacked sufficient blasting power.
Human cannoneering fell into desuetude until 1922, when Idelbrando Zacchini, an Italian circus acrobat who had witnessed Farini’s act as a child, revived it. With his sons he created a revolutionary new human cannon that was powered by air. Smoke clouds and a loud charge were merely added for effect. Idelbrando’s sons took turns being blasted out of the cannon. The act was an immediate sensation, and the Zacchini family Circus Olympia toured Europe before huge crowds.
John Ringling, the American circus impresario, spotted the Zacchini family cannonballs at Tivoli Gardens in Copenhagen. He brought the act – and the entire Zachinni family – back to America for the 1929 season. The family settled in Florida. Advances in cannon technology were continuous. Idelbrando’s sons Mario and Emanuel perfected the double human cannon in the early 30s. Altogether, five of Idelbrando’s seven sons were performing projectiles. Mario, the last surviving Zacchini cannonball from that first generation, has died at age 87.
The Zacchini brothers toured with the Ringling circus for several years, then opened their own traveling carnival in 1939. In the carnival they ratcheted up the act, shooting each other at speeds of up to 90 mph, 140 feet in the air, sometimes over two Ferris wheels.
“The net is very small up in the air,” Mario said. “Flying isn’t the hard part; landing in the net is.”
Mario retired after an accident at the World’s Fair in New York in 1940, in which the net collapsed and he broke some ribs and a shoulder.
“I healed pretty fast in those days,” Mario recalled. “I was like a cat, with nine lives. The eighth is gone. This is the ninth. After this one I’m gone.” How right he was.
Mario was also famed as one of the world’s greatest rope twirlers. He could turn a back flip through a lasso. After his retirement he toured the country for many years with his own carnival. The gaucho act was a big draw.
Constantly searching for new thrills for an easily-jaded audience, the Zacchini family developed the X-15 double canon in 1961. They rejoined the Ringling circus in 1966. In some years as many as five Zacchini cannonball acts were touring the states simultaneously. Edmondo Zacchini, one of Mario’s nephews, was the last human projectile in the family. His final flight was on Aug. 29, 1991.
The Zacchini family has bade farewell to the human cannoneering, yet new acts keep coming. Today’s human cannonball is more likely to be propelled by a bungee cord than by a burst of compressed air. But thanks to the visionary Zacchinis the world can still watch a hapless sack of bones sail over a Ferris wheel.