Kegelman Stadia Reduction Computer Circular Slide Rule
date: label: date made
content: after 1956
name: label: maker
content: Kegelman Bros.
notes: label: Description
content: This white plastic circular rule has a clear plastic indicator attached with a metal grommet in the center. The rule has scales of H (horizontal factor), theta (vertical angle), and V (vertical factor). A diagram on the instrument gives the formulas for these factors. The instrument is marked: KB (/) STADIA REDUCTION COMPUTER (/) KEGELMAN BROS. (/) HUNTINGDON VALLEY PA. (/) COPYRIGHT, 1956 (/) BY WILLIAM KEGELMAN P.E. It is in a cream-colored paper envelope stamped: WILLIAM KEGELMAN (/) 393 COUNTY LINE ROAD (/) HUNTINGDON VALLEY, PA.
label: Description
content: George Kegelman (1900–1985) began his career with Heller & Brightly of Philadelphia. He established his own shop around 1943 and began to work with his brother, William (1907–1985). In 1951, the pair formed Kegelman Brothers, which became best known for its Model 101 engineers transit. William Kegelman received a copyright (A245443) for this device, which was intended to process readings taken with the transit, on July 9, 1956.
label: Description
content: For other slide rules for reducing data from observations made with stadia rods, see MA.333636, 1977.1141.41, 1983.0472.01, 1987.0221.01, and 1987.0221.02.
label: Description
content: References: Robert C. Miller, "George Kegelman and Kegelman Brothers: Mathematical and Optical Instrument Makers," <i>Rittenhouse</i> 5 (1991): 56–58; Charles E. Smart, <i>The Makers of Surveying Instruments in America Since 1700</i> (Troy, N.Y.: Regal Art Press, 1962–1967); <i>Catalog of Copyright Entries: Books and Pamphlets</i>, 3rd ser. 10 (1956): 324, 1161; Kegelman Bros., <i>Instruction Manual for Engineers Transit</i> (Hunting[d]on Valley, Pa., 1957) 9–10 (see 2001.0282.02).
label: Location
content: Currently not on view
place: label: place made
content: United States: Pennsylvania, Lower Moreland Township
topic: label: Subject
content: Rule, Calculating
label: Subject
content: Mathematics
label: Subject
content: Surveying
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 Robert C. Miller
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 2001.0282.01
label: accession number
content: 2001.0282
label: catalog number
content: 2001.0282.01
objectType: label: Object Name
content: calculating rule
label: Object Name
content: slide rule
physicalDescription: label: Physical Description
content: plastic (overall material)
label: Physical Description
content: metal (part material)
label: Physical Description
content: paper (part material)
label: Measurements
content: rule: 12.9 cm; x 5 1/16 in
label: Measurements
content: overall: 13.2 cm x 13.2 cm x 13.2 cm; 5 3/16 in x 5 3/16 in x 5 3/16 in
label: Measurements
content: envelope: 13.3 cm x 13.3 cm; 5 1/4 in x 5 1/4 in