- 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
- Data Source
- National Museum of American History
- Kegelman Bros.
- copyright date; date made
- Credit Line
- Gift of Robert C. Miller
- Physical Description
- paper (overall material)
- overall: 18 cm x 12.8 cm; 7 3/32 in x 5 1/32 in
- Object Name
- documentation, slide rule
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