This microscope was owned by George H. Clapp (1858-1949), a cofounder of the Aluminum Company of America (ALCOA). He used it for his hobby, coin collecting. He had the lenses ground to his eyeglass prescription. Based on the serial number, we know it was made in 1924, and was likely used by Clapp in the preparation of his 1931 work, The United States Cents of the Years 1798-1799 and perhaps also used in preparation of his 1947 collaboration with Howard Newcomb, The United States Cents of the Years 1795, 1796, 1797, 1800.

The microscope is in a wooden case 33.5cm x 15.5cm x 18cm with a brass handle on top and a working brass lock and key on the front.

It has the following markings:
"GERMANY"
"E. LEITZ / Wetzlar"
"No. 220916"

It has two lenses marked 10.5x, and two other lenses marked 3.5x.

The microscope is from the estate of Glenn A. Mooney. A longtime numismatist and volunteer curator of the coin collection at the Carnegie Museum of Natural History in Pittsburgh, Mooney obtained the microscope from fellow Pittsburgher Jack Kennedy, who obtained it from the Clapp estate.