The Flintstones - Season 5, Episode 18: Time Machine . Aired Friday 8:30 PM Jan 15, 1965 on ABC
While at the Bedrock World's Fair, the Flintstones and the Rubbles laughingly step into a time machine, which they believe to be a hoax. But before long, they are transported to Ancient (but to them, future) Rome, Arthurian England, on board the ship of Christopher Columbus, and to Colonial America to meet Ben Franklin, and then of course- To The 1964 New York World's Fair.