Castaing machine Público Deposited
Named for Jean Castaing, the engineer who perfected it, this imparted edge ornamentation and/or edge lettering to planchets before striking. Mounted onto a bench were two parallel bars, each containing half the edge device, set apart minutely less than the blank's diameter, one fixed, the other spring-mounted and set to move forward at the pull of a long handle. Each blank passed through the machine, rolling enough to receive the complete edge device. In practice, slippage sometimes produced blundered edge inscriptions (parts missing or overlapping); more rarely, a blank might be run through a second time. Mint personnel commonly called the operation "rounding and edge marking." The machine went into use in the mid-17th century, becoming obsolete with the invention of the close collar. Until well into the 19th centur, its details (though long since published) were protected by oaths of secrecy exacted form workmen and Mint officers: Craig {1953}; Breen {1962A}; Ewing {1985}.
- Breen Encyclopedia