Charles Bruning 2401 Simplex Slide Rule
date: label: date made
content: 1944-1951
name: label: maker
content: Charles Bruning Company
notes: label: Description
content: This one-sided, five-inch white molded plastic linear slide rule has a glass indicator with a metal frame. The top edge is beveled and has a 12.5 cm scale, divided to millimeters. The top of the base has an A scale and is marked: CHARLES BRUNING CO. It is also marked: MADE IN U.S.A. The slide has B, CI, and C scales on one side and S, L, and T scales on the other side. The left end of the front of the slide is marked: 2401. The bottom edge of the rule is beveled and has a five-inch scale, divided to 32nds of an inch. Three screws on the back of the rule permit the top of the base to be adjusted.
label: Description
content: The instrument fits in a brown leather sleeve, which in turn fits in a red cardboard box. The box is marked: BRUNING (/) [Bruning logo of CB inside a diamond] (/) CHARLES BRUNING COMPANY, INC. A slip of paper inside the box advertises a magnifier that could be ordered for 60 cents from any of fourteen Bruning branch offices located across the United States. For an instruction manual received with the instrument, see 1991.0445.03.01.
label: Description
content: Charles Bruning (1866–1931) was born in Denmark and immigrated to the United States. In Chicago during the 1890s, he became interested in the blueprint business. In 1897 he set up his own blueprinting company in Manhattan, which was incorporated at the New York Blue Print Paper Company in 1901. Around 1920 he purchased American Blue Print Company of Chicago, and the combined firms became known as the Charles Bruning Company, Inc. The company's 1921 catalog lists eleven slide rules, although it is unclear whether any of these were actually manufactured by Bruning. By 1936 a new system of numbering was introduced. It assigned different model numbers to slide rules sold with different types of cases. This increased the number of model numbers to 14, but only 8 of these appear to be distinct. By 1952 most slide rules sold by Bruning were all-metal slide rules manufactured by Pickett & Eckel. This all-plastic rule is an exception.
label: Description
content: The instruction manual was copyrighted in 1944. This model is not shown in the 1939 Bruning catalog. By 1952 the indicator was of a different form. Hence, this rule likely dates from 1944 to 1951. The Charles Bruning Company merged with the Addressograph-Multigraph Corporation in 1963.
label: Description
content: References: New York Blue Print Paper Company, <i>Catalog</i> (New York, 1921), 155–157; "Charles Bruning," <i>New York Times</i> (January 31, 1931), 14; Charles Bruning Company, Inc., <i>General Catalog</i> (New York, 1936), 130–134; Charles Bruning Company, Inc., <i>General Catalog</i> (New York, 1939), 146–152; Charles Bruning Company, Inc., <i>General Catalog</i> (Teterboro, N.J. and Chicago, 1952), 121.
label: Location
content: Currently not on view
place: label: place made
content: United States: New York, New York City
topic: label: Subject
content: Mathematics
label: Subject
content: Rule, Calculating
setName: label: See more items in
content: Medicine and Science: Mathematics
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content: Science & Mathematics
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content: Slide Rules
creditLine: label: Credit Line
content: Gift of Richard R. Lombardi
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1991.0445.03
label: accession number
content: 1991.0445
label: catalog number
content: 1991.0445.03
objectType: label: Object Name
content: slide rule
physicalDescription: label: Physical Description
content: plastic (overall material)
label: Physical Description
content: glass (cursor material)
label: Physical Description
content: metal (part material)
label: Physical Description
content: leather (case material)
label: Physical Description
content: paper (case material)
label: Measurements
content: overall: 1.6 cm x 17.8 cm x 5.5 cm; 5/8 in x 7 in x 2 5/32 in