Brennan Adding Machine

This adding machine has a black case, with a green metal plate under the keyboard. It has nine black plastic digit keys arranged in a square with a “0” bar below. The digits are in white, with smaller complementary digits in red. There are red SUB (/) TOTAL and TOTAL keys to the left of the digit keys and a smaller red key to the right. Numbers of up to nine digits may be entered. Depressing the total key and the key on the right and bringing the lever forward clears the machine. At the front is a red key marked "E” that serves as a column indicator. Moving this key to the right eliminates digits entered erroneously. The metal operating lever, with wooden handle, is on the right side. Behind the keyboard is a glass window that reveals a row of nine plastic wheels that show the total. Behind these is a narrow carriage with a rubber knobs that carries a paper tape.
The Brennan was invented by Thomas Mehan and manufactured in Chicago in roughly the years from 1929 to1931. This was not a good time to be starting a business in the United States, and the Brennan Adding Machine Company soon folded. The rights to manufacture the machine were acquired by Remington Rand by 1932, and it soon began to manufacture a similar machine as its "grocer's special."
The machine is marked on the right and left side, with a stencil of an airplane: THE (/) BRENNAN. It is stamped on the bottom with serial number 4305.
The prior owner of the machine did not know where it was used.
This machine resembles that shown in an advertisement in Typewriter Topics, vol. 74, March, 1930. p. 61. It has more function keys than shown in 1929 advertisements.
E. Martin, Die Rechenmaschinen und ihre Entwicklungsgeschichte, (1925 edition with later supplement), p. 457.
Currently not on view
Object Name
adding machine
date made
ca 1930
Brennan Adding Machine Company
Physical Description
metal (overall material)
plastic (overall material)
paper (overall material)
rubber (overall material)
wood (overall material)
glass (overall material)
overall: 14 cm x 22.4 cm x 31.5 cm; 5 1/2 in x 8 13/16 in x 12 13/32 in
place made
United States: Illinois, Chicago
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, Kenneth E. Behring Center
Additional Media

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