Transit Instrument
date: label: date made
content: ca 1884
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 5740 Philadelphia." The serial number indicates that it was made around 1884. New, the basic transit cost $220. The vertical circle was an extra $25. The horizontal circle is silvered, graduated every 30 minutes of arc, and read by verniers at N and S to single minutes. There are level vials at N (this one covers a vernier) and at E. The vertical circle, also silvered, is read by vernier to single minutes, and is protected by an aluminum guard. To reduce weight, the vertical standards are ribbed and braced. The telescope is equipped with stadia wires for determining distances.
label: Description
content: The tripod head of this transit allows the instrument to be leveled, and also to be adjusted horizontally in order to be brought over a fixed point on the ground. Daniel Hoffman obtained a patent (#197,369) on this design in 1877, and assigned the rights to Heller & Brightly in exchange for $5 for each unit sold.
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
label: See more items in
content: Surveying and Geodesy
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content: Measuring & Mapping
publisher: label: Related Publication
content: Heller & Brightly. Remarks on Surveying Instruments
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: PH.328726
label: catalog number
content: 328726
label: accession number
content: 275808
objectType: label: Object Name
content: transit
physicalDescription: label: Measurements
content: overall: 15 1/2 in; 39.37 cm
label: Measurements
content: horizontal circle: 7 1/2 in; 19.05 cm
label: Measurements
content: vertical circle: 5 1/4 in; 13.335 cm
label: Measurements
content: needle: 5 in; 12.7 cm
label: Measurements
content: telescope: 11 1/4 in; 28.575 cm
label: Measurements
content: hanging level: 6 in; 15.24 cm
label: Measurements
content: overall: 18 1/8 in x 12 in x 9 1/2 in; 46.0375 cm x 30.48 cm x 24.13 cm