A chemistry professor has woken a dormant volcano in the middle of a European Unesco World Heritage site. Ordinarily, that might not sound like the best idea, but the volcano in question is quite a bit younger than most, having been built by a German prince in 1794.

Leopold III Friedrich Franz, prince and duke of Anhalt-Dessau, decided he quite liked the drama of a volcano after seeing Mount Vesuvius on his travels, explains an article in the Smithsonian. Not put off by the recent discovery of Pompeii's ashen ruins, the 27-year-old prince set about erecting Europe's only artificial volcano on his return home, building the Stone Island of Woerlitz, part of the Garden Realm of Woerlitz, in the middle of the German countryside south of Berlin. The "volcano" is made up of a five-storey high brick building covered in boulders. It houses a cone at the peak which conceals a chamber with three fireplaces and a fake crater. Franz completed his classical complex with an ampitheatre and a villa, before flooding the estate to create Stone Island. "He saw himself as obliged to enlighten his subjects, and he saw this as a lesson for people who would never get to Naples," Uwe Quilitzsch, the Woerlitz Garden Realm's staff historian, told the Smithsonian.

The 200-year-old structure remained dormant after Franz' death, his children not much interested in the spectacle. It was condemned by East German authorities in 1983 and left to decay, but in 2004 the World Heritage contacted Wolfgang Spyra, a professor of chemistry at the Brandenburg Technical University with a penchant for volcanoes, and asked him to help restore it. "A volcano that can't explode is a very sad volcano, and I wanted to make it happy again," said Spyra. "We wanted to help the volcano get its identity back."


Spyra uncovered texts describing how Franz and his friends would gather over a drink to watch the explosion, but other than that, there were few clues as to how to create an explosion besides a painting of the event. "We needed to figure out if it was a realistic depiction or fantasy," said Spyra. This was deduced by measuring the plume of smoke emerging from the painted volcano and working out whether it represented a realistic height. It was found the nine-metre-high plumes were within the range of what a natural fire would create.

The team then struck archaeological gold when they came across an eye-witness account of the event. The detailed description, while mocking the ludicrous site in the German countryside, revealed that an impression of flowing lava was created by using red lamps and releasing water from the artificial crater. Spyra and his team then gathered materials that would have been used in the 18th century, including gunpowder, pitch and sulphur. To recreate the explosion, something Spyra has been doing once a year since 2005, an eight-metre-square oven inside the crater is filled with pine needles and lit to create the smoke. Gas mask wearing participants then cover each of the wood-filled fireplaces in lighter fluid and throw in powder to create vivid coloured smoke piles that dramatically seep out. The water is then released, sliding down the volcano's side before tipping into the manmade lake below. Mortars, used by armies in the 18th century, are used to create the accompanying sparks and explosions. The volcanic explosion, though not as realistic as Syracuse University's lava car park experiments, which use basalt to recreate the real thing, is an impressive and arresting site in the middle of Germany.

Though Spyra and his team have turned the explosion into an annual occasion, he will not reveal when the next will take place, hoping to retain some of the mystery that was always designed to surround it. "Would you ask a volcano when it's going to go off?" he asked.

Source: Smithsonian

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