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# Hart's Mercantile Computing Machine

National Museum of American History

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                      -     DetailsRelatedObject Details- patentee
- Hart, William
- Scovill Manufacturing Company
- Description
- The instrument consists of three concentric brass discs, a brass marker, a steel stop, and a wooden handle (instrument must be removed from box to find handle). Each brass disc has the numbers from 0 to 99 stamped around the edge. The two inner discs both have a circle of 100 holes just outside the numbers. The inner holes are used to add the last two digits of a number by rotation. Any hundreds value in the sum carries to the second set of holes, which are used to add hundreds and thousands places.
- The machine is in a cylindrical wooden case with cover.
- According to the Kirksville [Missouri] Democrat for August 2, 1888, by then Hart had sold 3500 of these devices and “he lately ordered one thousand more.”
- References: U.S. Patent #199289
- P. Kidwell, "Adders Made and Used in the United States,"  Rittenhouse , 1994, 8:78-96.
- Kirksville [Missouri] Democrat , August 2, 1888.
- Location
- Currently not on view
- Credit Line
- Gift of Mrs. Robert T. Kerr
- 1878
- ID Number
- 1993.0510.01
- accession number
- 1993.0510
- catalog number
- 1993.0510.01
- Object Name
- adder with carry
- Physical Description
- steel (overall material)
- brass (overall material)
- wood (overall material)
- Measurements
- overall: 5.5 cm x 13.5 cm x 13.5 cm; 2 5/32 in x 5 5/16 in x 5 5/16 in
- place made
- United States: Connecticut, Waterbury
- place patented
- United States: Missouri, Kirksville
- See more items in
- Medicine and Science: Mathematics
- Adder
- Science & Mathematics
- National Museum of American History
- Subject
- Mathematics
- Record ID
- nmah_690274
- Metadata Usage (text)
- CC0
- GUID (Link to Original Record)
- http://n2t.net/ark:/65665/ng49ca746a5-0b41-704b-e053-15f76fa0b4fa
Related Content-                    Adders                American History Museum 
  Hart's Mercantile Computing Machine, Out of BoxCC0Creative Commons - No Rights Reserved iconUsage Conditions Apply>download icon>          There are restrictions for re-using this image. For more information, visit the Smithsonian's Terms of Use page .        International media Interoperability FrameworkIIIF provides researchers rich metadata and media viewing options for comparison of works across cultural heritage collections. Visit the IIIF page to learn more.View manifestView in Mirador ViewerExpand to view image×                PreviousNext             Footer logo      
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