Keuffel & Esser 4081-3 Log Log Duplex Decitrig Braille Slide Rule
date: label: date made
content: 1955-1961
name: label: maker
content: Keuffel & Esser Co.
notes: label: Description
content: Some engineers continued to use slide rules even when they lost their sight. This is such an instrument; it may have been adapted from Keuffel & Esser's original product by the American Foundation for the Blind. The ten-inch duplex rule is made from mahogany coated with white celluloid and held together with metal end pieces. It has an oversized plastic indicator with plastic edges and is held together with plastic dowels. Instead of a hairline there is a piece of wire held taut between 2 plastic pegs on the open frame of the indicator. One side of the base has LL02, LL03 and DF scales at the top and D, LL3, and LL2 scales at the bottom. The other side has LL01, L, K, A, D, DI, and LL1 scales. The slide has CF, CIF, CI, and C scales on one side and B, T, SRT, and S scales on the other. Some divisions on the A scale and both D scales on the base and the T, S, and C scales on the slide are marked with raised metal dots. Some of these dots indicate numbers in Braille.
label: Description
content: On one side, the right end of the slide is marked in red: © (/) K + E. On the other side, the left end of the slide is marked with a serial number: 397208. The left end of the top and the bottom of the base are both marked: 208. The top edge of the rule is marked: PATS. PEND. MADE IN U.S.A. 4081-3 LOG LOG DUPLEX DECITRIG ® COPYRIGHT 1947 BY KEUFFEL & ESSER CO. PATS. 2,500,460 2,168,056 2,170,144 2,285,722 2,422,649. Keuffel & Esser used this arrangement of scales on model 4081-3 from 1955 to 1962; the serial number suggests this example was made around 1958. See MA.318482 and 1990.0687.01 for nonadapted examples of model 4081-3. The instrument is in a very dark green leather sleeve fitted to the oversized indicator.
label: Description
content: This slide rule belonged to Moritz Otto Shollmier (1931–1972), the late husband of the donor. He was a mechanical engineer who graduated from the School of Engineering at the University of Arkansas in 1956. He lost his sight in 1961 as a result of the effects of diabetes and used this instrument for several years to design heating and air conditioning projects. He was also an avid ham radio operator.
label: Description
content: References:
label: Description
content: Ed Chamberlain, "Estimating K&E Slide Rule Dates," 27 December 2000, http://www.sphere.bc.ca/test/ke/320-k+e_date2.jpg.
label: Description
content: Accession file.
label: Description
content: Gordon Anthony, "The K&E Braille Slide Rule," <i>Journal of the Oughtred Society</i> 2, no. 1 (1993): 19–20.
label: Description
content: "Keuffel & Esser Braille Slide Rule," 2006.011.001
label: Description
content: MIT Museum, http://webmuseum.mit.edu/detail.php?t=exhibitions&type=exh&f=&s=32&record=7.
label: Description
content: "In Memory of WA5EFL Moritz Shollmier," http://www.geocities.com/CapeCanaveral/Hangar/4073/wa5efl.html (accessed October 24, 2001).
label: Location
content: Currently not on view
place: label: place made
content: United States: New York, New York City
topic: label: Subject
content: Rule, Calculating
label: Subject
content: Braille
label: Subject
content: Mathematics
setName: label: See more items in
content: Medicine and Science: Mathematics
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content: Science & Mathematics
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content: Trigonometry
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content: Slide Rules
creditLine: label: Credit Line
content: Gift of Liane Humble
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: MA.334387
label: catalog number
content: 334387
label: accession number
content: 313987
objectType: label: Object Name
content: slide rule
physicalDescription: label: Physical Description
content: wood (overall material)
label: Physical Description
content: celluloid (laminate material)
label: Physical Description
content: metal (part material)
label: Physical Description
content: leather (case material)
label: Physical Description
content: plastic (cursor material)
label: Measurements
content: overall: 2 cm x 33.8 cm x 10.2 cm; 25/32 in x 13 5/16 in x 4 1/32 in