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Dental malletIn 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.*
A cop waited outside a popular pub hoping to nab a drink-driver.
At closing time, as everyone came out, he spotted his potential quarry.
The man was so obviously inebriated that he could barely walk.
He stumbled around the parking lot for a few minutes looking for his car.
After trying his keys on five others, he finally found his own vehicle.
He sat in the car a good 10 minutes as the other pub patrons left.
He turned his lights on, then off.
He started to pull forward into the grass, then stopped.
Finally, when his was the last car, he pulled out onto the road and started to drive away.
The cop, waiting for this, turned on his lights and pulled the man over.
He administered the breathalyzer test and, to his great surprise, the man easily passed.
The cop was dumbfounded.
'This equipment must be broken,' exclaimed the policeman.
'I doubt it,' said the man. 'Tonight I'm the designated decoy.'