Fireside Favorites: Encyclopedia Brown and the Case of the Balloon Man

Maggie Reads Jon an Encyclopedia Brown mystery and he tries to solve it.  Can you solve the case of the Balloon Man, a case that has perplexed even the Chief of Police of Idaville before Jon can?  (I wouldn't get too worked up.  Chief Brown is stalwart and true, but his deductive reasoning skills are dangerously lacking, considering his job).