The Counterfeit Coin Detector Patent Archive

Every device ever patented to catch a bad coin

Patented March 20, 1877

If an object in your hands says PAT. MARCH 20, 1877, it may be one of these.

PatentTitleInventorOf
US 188,712IMPROVEMENT IN COUNTERFEIT-COIN DETECTERSJohn WiardaGreen Point, New York

All dates