United States of America "Proof Plate" from Heath's Counterfeit Bond Detector - Fantastic Engraving

"Proof Plate" from Heath's Counterfeit Bond Detector. Superb! Great! The book's first appearance was in 1864, when the Civil War would have been encouraging a lot of funny money. The author also marketed a microscope, advertised in this manual, that could be used to study folding money. From Abebooks.com