3x11 - The Busy World of Richard Scarry

A big riddle race takes place in Busytown starting at the Fire station (with the riddle "When things get really hot, we'll bring you some water") and ending at the Observatory (with the riddle "When it gets dark, look up and watch the show"), the story of the first balloon (a.k.a. Montgolfier) is featured and Billy Dog loses a meteorite from the observatory and tries to find and return it.