# Odhner Arithmometer

Description
This is one of the first calculating machines built on the design of Willgodt T. Odhner (1845–1905), a Swedish engineer working in St. Petersburg, Russia, in the factory of another Swede, Ludwig Nobel.
In the early 1870s, Odhner sought to improve his fortune by inventing a calculating machine. He prepared a prototype in 1875, a model in 1876 and in 1877 arranged to have 14 machines built at the Nobel factory. This is one of these machines. Like Frank S. Baldwin of St. Louis, Odhner represented digits by retractable pins that extended from the edge of metal discs. Rotating the disc had an effect proportional to the number of protruding pins. Pinwheel calculating machines came to sell widely.
This lever-set non-printing machine has a black cast–iron frame with eight brass pinwheels and a wooden base. Numbers are set by rotating the pinwheels forward using levers that extend from the wheels. Windows between the pinwheels show the number set. Commas are painted on the case to indicate decimal divisions.
The carriage is at the front of the machine, with a seven-digit revolution counter at the very front and a ten-digit result register behind this. Seven brass screws rotate to set numbers in the revolution register. Rotating a wing nut on the right of the carriage zeros the result register, and turning a crank on the left of the revolution counter zeros it. A crank at the right end of the carriage may be designed to release it. A crank with an ivory knob on the right side of the machine is rotated counterclockwise for addition and multiplication and clockwise for subtraction and division.
A mark at the top of the machine reads: W. Odhners (/) ARITHMOMETER. A second, underlined, mark there reads: L. Nobel. A third, underlined, mark there reads: St. Petersburg. The number “9” has been stamped several places that are visible when the case is opened. Specifically, it is found on the top edge of the bottom of the case and the bottom edge of the top of the case, on a gear inside the crank, and on the right side of each of the pinwheels.
Compare MA.323605.
This machine was owned by Joseph S. McCoy, actuary of the U.S. Treasury Department.
References:
E. Martin, The Calculating Machines (Die Rechenmaschinen), trans. P. A. Kidwell and M. R. Williams, Cambridge: MIT Press, 1992, esp. p. 67, figure 36.
Timo Leipaelae, “The Life and Works of W. T. Odhner,” Greifswalder Symposium zur Entwicklung der Rechentechnik, ed. W. Girbardt, Greifswald: Univ. Greifswald, Inst. für Mathematik und Informatik, 2003 and 2006.
Location
Currently not on view
1877
maker
Nobel, L.
Rossiya: Rossiya, St. Petersburg
Physical Description
iron (overall material)
ivory (overall material)
brass (overall material)
wood (overall material)
Measurements
overall: 13.5 cm x 28 cm x 17.5 cm; 5 5/16 in x 11 1/32 in x 6 7/8 in
ID Number
MA.310231
accession number
113246
catalog number
310231
Credit Line
Gift of Mrs. Joseph S. McCoy
subject
Mathematics
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Calculating Machines
Data Source
National Museum of American History