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Item ST 22215 Altitude & Azimuth Instrument - 12-inch, Troughton & Simms, London, England, circa 1836

Summary

Altitude & azimuth instrument, 12 inch circle, made by Troughton & Simms, London, circa 1836

This instrument was used for the Geodetic Survey of Victoria, 1858-71, which established the primary surveying points throughout the colony. Also used at Melbourne Observatory.

Physical Description

Altitude circle 11 inches and azimuth circle 12 inches. Circles graduated on silver every 10 minutes & read by verniers. In two wooden boxes: 1. stand and horizontal circle; 2. telescope and vertical circle.

More Information

Collection Names

Melbourne Observatory Collection
Collecting Areas

Engineering, Science & Measurement
Acquisition Information

Transfer from Melbourne Observatory, 1945
Maker

Troughton & Simms, London, Middlesex, England, Great Britain, circa 1836
User

Victoria: Geodetic Survey of Victoria, Victoria, Australia, 1858-1871
User

Melbourne Observatory, South Yarra, Greater Melbourne, Victoria, Australia, 1863 or later
Inscriptions

Marked "S.G.O. 100" [ie Surveyor General's Office]
Classification

Surveying & navigation, Optical - surveying, Angular measurement
Category

History & Technology
Discipline

Technology
Type of item

Object
Keywords

Geodetic Surveys, Surveying Apparatus & Instruments, Theodolites