You know Alexander Graham Bell invented the telephone. But did you also know that the Edinburgh-born innovator is the person we have to thank for the metal detector? He devised the contraption not as a way to look for loose change and other left-behind items on the beach, but in an attempt to help save the life of President James Garfield. (Spoiler alert: Garfield died anyway.)

In this week's all-new edition of The List Show, Mental Floss editor-in-chief Erin McCarthy is sharing the details of 35 key—but lesser-known—inventions devised by some of the world's greatest inventors.

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