Surveyor's Transit
date: label: date made
content: 1891-1916
name: label: maker
content: Sala, Joseph Charles
notes: label: Description
content: This is marked "J. C. SALA MAKER SAN FRANCISCO 825." Sala termed it an Engineer's Complete Transit, and priced it at $235. The horizontal circle is silvered, graduated into 64 units (each equal to 100 mils), and read by opposite verniers to 30 parts. One mil (or military degree) equals 3.375 arc minutes. A variation arc, outside the compass at E, extends 30 degrees either way; the vernier reads to single minutes. The vertical arc, also silvered, is graduated into 30 minutes of arc, and read by vernier to single minutes. There is a clamp and tangent attachment to the telescope axis, as well as a gradienter attachment for determining gradients, distances, and differences of level.
label: Description
content: Joseph Charles Sala (1841-1916) was born in Italy, moved to San Francisco around 1861, and worked for John Roach. Following Roach's death in 1891, Sala went into business for himself, advertising as "Successor to John Roach" and noting his many awards from the Mechanics' Institute of San Francisco.
label: Description
content: Ref: J. C. Sala, <i>Illustrated Catalogue and Manual of Civil Engineers' and Surveyors' Instruments</i> (San Francisco, 1896).
label: Location
content: Currently not on view
place: label: place made
content: United States: California, San Francisco
topic: label: Subject
content: Italian Americans
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: Sala, J. C.. Illustrated Catalogue and Manual of Civil Engineers' and Surveyors' Instruments
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1985.0599.01
label: accession number
content: 1985.0599
label: catalog number
content: 1985.0599.01
objectType: label: Object Name
content: surveyor's transit
physicalDescription: label: Measurements
content: overall: 10 1/2 in; 26.67 cm
label: Measurements
content: horizontal circle: 6 in; 15.24 cm
label: Measurements
content: needle: 4 1/4 in; 10.795 cm
label: Measurements
content: telescope: 10 1/2 in; 26.67 cm
label: Measurements
content: hanging level: 5 in; 12.7 cm
label: Measurements
content: overall: 13 7/8 in x 6 7/8 in x 10 1/2 in; 35.2425 cm x 17.4625 cm x 26.67 cm