The experience is a testament to the power of Franz's obsession—and a monument to a pivotal experience of his youth. "He obviously saw it in Italy, and this was the German answer," says Quilitzsch. "By the standards of the time, it was a remarkable achievement."
Yet after Franz's death in 1820 the eruptions ceased. His sole legitimate son had no interest in such diversions. Though most of Franz's elaborately planned "Garden Realm" was preserved after his death, over the next 150 years or so the volcano was neglected. After World War II, the area became part of East Germany, and the volcano fell into further ruin. "The last eruptions were just burning tires," says Heiko Pilz, one of Spyra's graduate student assistants. "It was overgrown with weeds and falling apart." East German authorities finally condemned it in 1983, after part of it collapsed and killed someone.
The volcano still has secrets, of course. "I wonder how they did the noise," says graduate student Jonas Lohmann, dousing the fireplaces with lighter fluid and smoke powder a few hours before Saturday's eruption. "Nowadays we have hi-fi speakers, but back then? No idea."
And just as there's no way to know exactly what contemporary audiences saw when they gathered on the banks of Franz's ersatz Gulf of Naples, we'll never know what they felt as they watched flame and smoke churn out of Franz's flight of fancy.
Skeptical accounts aside, Quilitzsch and Spyra are convinced the volcano must have been a truly impressive—even frightening—sight for Franz's peers and subjects. "They wanted to be transported – the era was defined by poverty and plunder, and people relished spectacles and distractions," Spyra says.
Spyra and Quilitzsch are enthusiastic showmen, but they're also wary of cheapening the volcano's romance through over-exposure. "We don't want to make this into a daily, mundane event," Spyra says.
Since the volcano first rumbled back to life in 2005, Spyra and Quilitzsch have staged just a dozen eruptions, roughly once a year and never on the same dates (this year it was on the anniversary of the A.D. 79 Vesuvius eruption). They won't say when the next eruption will be. Says Quilitzsch: "Would you ask a volcano when it's going to go off?"