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Jim Davis

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Dental mallet

In 1875, the first U.S. patent for a dental mallet, or "Electro-magnetic Dental Pluggers" was issued to William G.A. Bonwill of Philadelphia, Pa. (No. 170,045). His tooth-filling device was used to drive gold into a tooth cavity. He derived the idea from observing the sounder of a telegraph key (while at the Continental Hotel in Philadelphia, 27 Feb 1867). The automatic tool was designed to be "manipulated as readily as the usual hand-tools." An electromagnet functions to drive a mallet, while also breaking the circuit to allow the spring-loaded mallet to return, at which point the circuit is closed, and the cycle repeated under the control of the operator.*

There was a sign han...

“There was a sign hanging in the window of a dry cleaners I passed by. It read: 'So-and-So Dry Cleaners. Working on the same spot for 72 years.'”

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