Toms builds scale-model catapults in his small Sherman Oaks, California, factory. He makes a tabletop model that can hurl small wooden missiles more than 20 feet, and a 5-foot Warwolf trebuchet that's one-tenth the size of the one used during King Edward's medieval battles with the Scots. German engineering schools especially like his original floating-arm trebuchets. They use them to demonstrate the principle of efficiency. Toms has also sold a special catapult to a paraplegic who "needed a machine that could throw tennis balls for his dog." The devices, Toms says, are both simple and endlessly profound. "A trebuchet, with a counterweight on one end and a slingshot on the other, is a double compound pendulum. Math professors sometimes use them to study chaos theory."