Barbour Calculating Machine Model

Barbour Calculating Machine Model

In the late 19th century, several inventors turned their attention to designing better machines for doing arithmetic. This model calculating machine, patented by Edmund D. Barbour of Boston, was intended to multiply a number by a digit directly, rather than requiring repeated addition. Barbour submitted the model to the U.S. Patent Office, and received a patent for the invention on August 13, 1872.
This machine consists of eight wooden cylinders that rotate on a crosswise shaft inside a wooden box. Each cylinder has around its edge 90 rows of cog-teeth. Each set of nine cog-teeth represents the multiples of a digit (zero multiples correspond to blank spaces). These cog-teeth have not actually been constructed. They are shown as pen marks on a slip of paper that extends around the first cylinder.
The machine is set to a given multiplier by rotating all the cylinders with a knob at one end of the machine. This knob is missing. The first cylinder has on its left side a wooden spur gear with 90 teeth The other cylinders would have such gears, but they are uncut. Pulling out a wooden toothed rack below the gear advances it one-ninetieth of a revolution for each unit on the rack. Hence one can set a multiplicand.
A movable carriage of brass on the top of the machine is supposed to be linked to the cylinders, so that when the carriage is pulled one unit to the right, the recording wheels advance in proportion to the figure represented on the edge of the cylinders. At present, the cylinders are not linked to the sliding carriage. Ther object has no maker’s marks. No successful product emerged directly from Barbour’s patents.
Compare MA.309172, MA.309173, and MA.318168.
The Edmund D. Barbour who took out this patent was probably Edmund Dana Barbour (1841–1925), a Boston native who reportedly gained a fortune in the China trade, before returning to Boston in 1871, not long before taking out this patent. Barbour went on to take out two further patents for calculating machines, to invest successfully in the Bell Telephone Company, to carry out extensive genealogical research, and to leave most of his fortune in bequests to Harvard University, the Massachusetts Institute of Technology and Radcliffe College.
Edmund Barbour, "Improvement in Calculating-Machines," U.S. Patent 130404, August 13, 1872.
J. A. V. Turck, Origin of Modern Calculating Machines, Chicago: Western Society of Engineers, 1921, pp. 180–187.
“Sharon’s Rich Men,” Boston Daily Globe, February 20, 1888, p. 6.
“Fund for Three Local Colleges: Edmund D Barbour’s Will Gives Each $20,000 a Year,” Boston Daily Globe, March 13, 1925.
J. Gardner Bartlett, “Edmund Dana Barbour,” The New England Historical and Genealogical Register , vol. 79, October 1925, pp. 339–344.
Currently not on view
Object Name
calculating machine
Object Type
Patent Model
date made
Barbour, Edmund D.
Barbour, Edmund D.
place made
United States: Massachusetts, Boston
place patented
United States: Massachusetts, Boston
Physical Description
wood (overall material)
brass (overall material)
overall: 14 cm x 41 cm x 13 cm; 5 1/2 in x 16 5/32 in x 5 1/8 in
ID Number
accession number
catalog number
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Calculating Machines
Data Source
National Museum of American History
Nominate this object for photography.   

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.


Add a comment about this object