February 27, 1877 Patent Berrian Gold &Silver Counterfeit Detector for United States coins. Newman-Mallis IV-3-1. Bent plate rocker style detector. Nickel plated brass. Choice Extremely Fine.Fairly bright with no losses to the heavy plating. Some pale gray patina and scattered flecks are noted under magnification. Though marketed by Berrian Manufacturing Company of New York, this type was actually patented by John A. Thompson and was the first of his three counterfeit detector patents.
