The mangonel has a rather gruesome history. In the Middle Ages, the device, said Scott Sprehn of Minneapolis, was used during warfare to hurl items at castles and other fortifications. The besiegers would toss pots of burning material, plague-ridden rats and body parts, he said.
At last year's Medieval Fair at Caponi Art Park, though, it was mostly used to launch tennis balls.
Sprehn has constructed several of the siege engines for the event, and he'll have one at this year's fair on Sunday in Eagan.
"Mostly, it was just used to launch rocks," Sprehn admitted. "It was pretty effective."
Sprehn, who works in set design and construction at the Children's Theatre Company in Minneapolis, said his bowl-shaped catapult flings balls 30 or 40 feet. If last year was any indication, it will be a big draw.
"I had a pretty long line the whole time," said Sprehn. "The engine never really shut down."
There will be plenty of other hands-on activities and demonstrations at the seventh-annual event. "The fighting is pretty popular, too," said Medieval Fair coordinator Liz Pearson. Crowds can watch armored full contact and rapier fighting.
The fair also gives a picture of tamer, domestic life in the Middle Ages, with demonstrations including fire starting, spinning, lacemaking and coin making. Visitors can also play games such as backgammon and chess, as well as medieval strategy games like "Fox and Geese."
Pearson, who does cooking demonstrations, said that organizers try to do something different each year. In the past, they have demonstrated ancient ways of making cheeses or mustard.
"It's just a little different," she said. "The spices might be a little different, and the cooking method obviously was a little bit different."
This year, they will serve sauerkraut and discuss food preservation.
Entertainment includes a storytelling bard and a musical group -- made up of a recorder, guitar and violin -- who perform and teach basic rounds and dances. Also new this year are Angora goats and rabbits.
The event is put on by a local chapter of the Society of Creative Anachronism, a group dedicated to showcasing the arts and skills of pre-17th century Europe. Last year, it drew about 1,400 visitors.
Pearson said she enjoys "providing people a different view on history. History can be pretty dry. This puts a more human spin on history, and I like that."
Cheryl Caponi, executive director at the park, said that not everyone likes going to a museum, so the fair offers a good way to learn about history out in nature.
"It's certainly one of the most fun events that we have out here," said Caponi.
"It's the Middle Ages the way it should be, without all the disease and pestilence."
Liz Rolfsmeier is a Twin Cities freelance writer.