The Myth - Under siege from a neighboring clan, a MedievalHungarian town (Paks) built a cannon out of a tree overnight, but wiped out a great deal of itself when the cannon exploded during a test-fire.
Verdict - Plausible
Notes - It is impossible to bore a barrel out of a log in a single night using the technology available at that time, and Adam eventually used a chainsaw and electric drill. The cannon made of a log, loaded with 6oz of period-realistic gunpowder, successfully fired a 1lb hand-chiseled granite cannonball a huge distance (exact measurement unknown since the cannonball was never found, even after 9 years). It also successfully fired a tennis ball, though a soda can merely leaked and contaminated the gunpowder. Loaded with 5lb of gunpowder, and with its barrel plugged, the tree cannon exploded violently enough to feasibly destroy part of a small medieval town. Since the testing of this myth, Jamie still looks for the cannonball in the bushes around the runway every time he does a myth on the runway.