Its popularity led to many copycat devices, including the Operator's Bell, which sometimes came with a chewing gum reward to circumvent strict gambling laws. The Liberty Bell was a simple automatic mechanism with three reels that could read sequences to give a payout for certain combinations. The colorful symbols have tempted players to try their luck for well over a hundred years, going back to the famous Liberty Bell machine invented by Herbert Mills in 1907. Fruit slot reels are one of the most iconic images in the gambling world.