Surveyor's Transit
name: label: maker
content: Heller & Brightly
notes: label: Description
content: Heller & Brightly advertised this as an Improved Complete Combined Transit and Leveling Instrument For Civil Engineers and Surveyors. This example is marked "Heller & Brightly Makers 5512 Philadelphia." It was made around 1882 and cost $220 new. The horizontal circle is silvered, graduated every 30 minutes of arc, and read by two verniers to single minutes; one vernier is covered by a level vial. The vertical arc, also silvered, is read by a single vernier to 30 seconds. The joints are sealed to keep dust out of the working parts. To reduce weight, the vertical standards are ribbed and braced. To reduce backlash, the tangent screw is provided with a fixed spiral spring and follower.
label: Description
content: This instrument is equipped so that a surveyor can determine horizontal distances by observing a distant graduated rod. To that end, it has an exceptionally powerful telescope, and its eyepiece has two horizontal wires so arranged that they encompass a tenth of a foot on a rod placed at a distance of 100 feet. Stadia surveying, as this practice is known, originated in Europe in the late 18th century and was introduced to the United States in the 1840s. The box in which the transit is packed is equipped with springs to accommodate the instrument in any direction. A solar attachment designed by George N. Saegmuller, and marked "HELLER & BRIGHTLY MAKERS PHILA." and "PAT. May 3. 81," is included.
label: Description
content: Ref: Heller & Brightly, <i>Remarks on Surveying Instruments</i> (Philadelphia, 1886).
label: Location
content: Currently not on view
place: label: place made
content: United States: Pennsylvania, Philadelphia
setName: label: See more items in
content: Medicine and Science: Physical Sciences
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content: Surveying and Geodesy
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content: Measuring & Mapping
publisher: label: Related Publication
content: Heller & Brightly. Remarks on Surveying Instruments
creditLine: label: Credit Line
content: University of Pittsburgh
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.334889
label: catalog number
content: 334889
label: accession number
content: 315134
objectType: label: Object Name
content: transit
physicalDescription: label: Measurements
content: overall (without leveling base): 11 1/2 in; 29.21 cm
label: Measurements
content: horizontal circle: 7 1/2 in; 19.05 cm
label: Measurements
content: magnetic compass: 5 1/4 in; 13.335 cm
label: Measurements
content: telescope: 11 1/2 in; 29.21 cm
label: Measurements
content: hanging level: 6 1/4 in; 15.875 cm
label: Measurements
content: overall in case: 13 1/4 in x 9 in x 13 5/8 in; 33.655 cm x 22.86 cm x 34.6075 cm