Hatfield Machine for Adding Numbers

Wooden paddle-shaped device mounted on one side with three brass concentric dials or numbered discs covered by a drop-shaped arm with small knob, angled metal strip and rectangular window cutout. The largest disc (stamped from 1 to 99 around its edge with a blank space for zero) is secured to the paddle while the middle disc (numbered from 100 to 9900 in increments of 100), the top disc (numbered from 1 to 99, each with corresponding nail mark) and the arm rotate around a domed fastener with brass pin at center; the metal strip and nail marks on the top dial act as a ratchet. Maker and patent information stamped in roman letters on front of arm.
Maker is Aaron L. Hatfield of Lewisburg, PA, who received U.S. Patent No. 11,726 for his "Calculator" or "Machine for Adding Numbers" on September 26, 1854.
Currently not on view
Object Name
device, number addition
patent date
Hatfield, Aaron L.
Physical Description
brass (discs; arm material)
steel (metal strip material)
iron (fastener; knob material)
mahogany (paddle material)
overall: 1 1/8 in x 9 5/8 in x 5 in; 2.8575 cm x 24.4475 cm x 12.7 cm
place made
United States: Pennsylvania, Lewisburg
ID Number
accession number
catalog number
Domestic Furnishings
See more items in
Home and Community Life: Domestic Life
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of John Paul Remensnyder
Additional Media

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