Automatic Arithmotor

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This U.S. Patent Office model for an adding machine has eight counting wheels that rotate on a common crosswise shaft. Around the edge of each wheel, the digits from 0 to 9 are printed repeatedly. Attached to each cylinder is a toothed revolving disc. The machine has a wooden case with a tin cover over the wheels. On the cover, next to each wheel, is a slip of paper labeled with the numbers from 1 to 9. To enter a number, one places one's finger at the tooth next to the digit on the appropriate paper slip, and rotates forward. The sum appears in slots in the metal cover, near the top of the machine. Each wheel has four cams linked to a weighted pawl-lever, which is responsible for carrying.
The inventor was Reuben [sic] R. James, an Indiana native born in August, 1826. According to Census records, he was a farmer (1850, 1860) and then the proprietor of a woolen mill (1870) in Rising Sun, Indiana. He took out this patent in 1878. James and fellow Rising Sun resident Mirabeau N. Lynn took out a patent for a grain meter in 1881.
U.S. Patent 209690, November 5, 1878.
U.S. Patent 238122, February 22, 1881.
Currently not on view
date made
James, Reuben R.
James, Reuben R.
place made
United States: Indiana, Rising Sun
place patented
United States: Indiana, Rising Sun
Physical Description
wood (overall material)
metal (overall material)
cork (overall material)
paper (overall material)
overall: 21.5 cm x 20.2 cm x 20.2 cm; 8 15/32 in x 7 15/16 in x 7 15/16 in
ID Number
accession number
catalog number
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Adding Machines
Data Source
National Museum of American History


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