Facit ESA-0 Calculating Machine

This ten-key non-printing electric pinwheel calculating machine has an iron frame painted dark green. It has fully automatic addition, subtraction, multiplication, and division, as well as electric clearing of registers.
A lever on the front left sets the machine for multiplication, addition (and subtraction), or division. There are five function keys and three tab keys. All the key tops are plastic. Plastic-covered windows reveal the number wheels of the product register, multiplier register, and setting mechanism. Included are a plastic cover, rubber cord, and leather-covered wood case.
A mark on the bottom of the machine reads: 347409. A tag on the back reads: MOD.ESA-0 (/) Fi (/) 105-115V = 65W. Another tag on the back reads: MADE BY (/) ATVIDABERG-FACIT (/) SWEDEN (/) Protected by patents in Sweden and other countries. A mark on the front reads: FACIT. The digit keys are marked: 2 4 5 7 9 (/) 1 3 0 6 8. A name tag attached to the case reads: WILLIAM C. ZAHN.
The Swedish firm of Facit Calculator began manufacturing pinwheel calculating machines in 1918 and became Facit in 1924. In 1932 it began to manufacture a ten-key calculating machine. The ESA-0 is an electric, fully automatic version of that machine, with electric clearing of registers. It sold from 1949 through 1952.
According to the donor, this machine was used by her husband, William C. Zahn, in his wide-ranging research on organic chemistry, the senses, the weather, and economics.
For related documentation, see 1996.0033.02, 1996.0033,03. and 1996.0033.04.
FACIT Kalkylmaskiner - samitliga modeller, Stockholm, 1961.
Currently not on view
Object Name
calculating machine
date made
Physical Description
plastic (overall material)
metal (overall material)
overall: 20.5 cm x 34.5 cm x 33 cm; 8 1/16 in x 13 19/32 in x 13 in
place made
Sverige: Östergötland, Åtvidaberg
ID Number
catalog number
accession number
maker number
See more items in
Medicine and Science: Mathematics
Science & Mathematics
Calculating Machines
Data Source
National Museum of American History, Kenneth E. Behring Center


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