Kegelman Instruction Manual for Engineers Transit

This 20-page booklet was received with 2001.0282.01. Surveyors used stadia computers to reduce the data they collected from making observations with a transit and a stadia rod, to determine the vertical angle of elevation and the horizontal distance of the stadia rod.
William Kegelman, who manufactured transits with his brother and partner, George, from about 1944 to 1988, copyrighted a "stadia reduction computer" in 1956. This device is described on pages 9–10 of the booklet; the booklet's citation information is Kegelman Bros., Instruction Manual for Engineers Transit (Hunting[d]on Valley, Pa., 1957).
Reference: Robert C. Miller, "George Kegelman and Kegelman Brothers: Mathematical and Optical Instrument Makers," Rittenhouse 5 (1991): 56–58.
Currently not on view
Object Name
documentation, slide rule
copyright date; date made
Kegelman Bros.
Physical Description
paper (overall material)
overall: 18 cm x 12.8 cm; 7 3/32 in x 5 1/32 in
place made
United States: Pennsylvania, Huntingdon Valley
ID Number
accession number
catalog number
Science & Mathematics
Rule, Calculating
Slide Rules
See more items in
Medicine and Science: Mathematics
Slide Rules
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of Robert C. Miller
Additional Media

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