| Prototypes of different slot machines already began circulating in the 1870's, several years before the German entrepreneur, Charles Fey, invented the three reel slot machine in 1895. By 1907, Fey had perfected the machine which then became known as the "Mills Liberty Bell." The Liberty Bell used strips displaying three different playing cards, a casing made from cast iron, and a bell that would ring to signal a winning combination. Three years later, the Operator Bell was created featuring fruit symbols in place of playing cards. Both machines weighed over 100 pounds each and were eventually replaced with lighter and quieter designs in the 1930's. During the 30's and 40's, the popularity of slot machines reached incredible heights in casinos across America. The Mills Novelty Company, working in cooperation with Fey, introduced slot machines that each had their own theme design to catch people's attention. As technology progressed, slot machines became more modernized using electronic devices and computer programs. Slot machines quickly took over casinos, bringing in two thirds of all casino revenue by 1990. Today, slots continue to dominate casinos due to their ongoing popularity and innovations in design. |