historical coins

Published in 1976, Gerhard Welter’s (1907-1989) Cleaning and Preservation of Coins and Medals provides insight on the best practices for maintaining and protecting coins against erosion, rust, and decay. In addition to providing instructions, the book also features illustrations of apparatuses used for cleaning coins made from different metals. Welter's work as a numismatist specializing in the study of coins of old noble families in Europe was not his primary career, however. He made his living as a businessman for an office machine company in Germany.