Mining Transit
date: label: date made
content: 1917
name: label: maker
content: C.L. Berger and Sons
notes: label: Description
content: This instrument is marked "C. L. Berger & Sons Boston, USA." The firm termed it a Universal Mining Transit with Duplex Telescope Bearings, noting that C. L. Berger had designed it on June 10, 1889, in order "to meet the requirements of the Mining Engineer, who must have the exact location of every shaft and tunnel in a mine" and who needed to get "the closest results under the most trying circumstances." It could measure horizontal angles between points, "one of which may be depressed as much as eighty or ninety degrees below the horizon, while the other may be as much elevated above the horizon; and also to measure with equal accuracy angles of elevation or depression above or below the horizon." The distinctive feature of this transit is that the telescope can be mounted in the center of the instrument, as usual, or, for extreme angles, it can be moved to the front of the instrument, with a counterweight attached to the back.
label: Description
content: The Berger records indicate that C. Elliott of Pittsburgh ordered this instrument in February 1917. The horizontal and vertical circles are silvered, graduated to 30 minutes of arc, and read by opposite verniers to single minutes. With lamp, two tripods, and two plumb bobs, the instrument cost $620.
label: Description
content: Ref: C. L. Berger & Sons, <i>Hand-Book and Illustrated Catalogue of the Engineers' and Surveyors' Instruments of Precision</i> (Boston, 1912), pp. 172-177.
label: Description
content: Chicago Steel Tape-Berger Instruments (Document Management Systems, 1995), Book 36, p. 64.
label: Location
content: Currently not on view
place: label: place made
content: United States: Massachusetts, Boston
setName: label: See more items in
content: Medicine and Science: Physical Sciences
label: See more items in
content: Surveying and Geodesy
label: See more items in
content: Measuring & Mapping
publisher: label: Related Publication
content: C. L. Berger & Sons. Hand-Book and Ilustrated Catalogue of the Engineers' and Surveyors' Instruments of Percision
creditLine: label: Credit Line
content: University of Pittsburgh
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.334893
label: catalog number
content: 334893
label: accession number
content: 315134
objectType: label: Object Name
content: transit
physicalDescription: label: Measurements
content: overall: 12 1/2 in; 31.75 cm
label: Measurements
content: horizontal circle: 5 in; 12.7 cm
label: Measurements
content: vertical circle: 5 in; 12.7 cm
label: Measurements
content: telescope: 9 in; 22.86 cm
label: Measurements
content: striding level: 5 in; 12.7 cm
label: Measurements
content: overall: 15 1/8 in x 10 1/2 in x 11 3/8 in; 38.4175 cm x 26.67 cm x 28.8925 cm