Summary
Theodolite, 13 inch horizontal circle and 9 inch vertical circle, by Ertel & Sohn, Munich. Horizontal circle is graduated to 5 minutes and vertical circle to 15 minutes.
It is likely that this is the 'Universal Instrument' by Ertel listed by George Neumayer as part of the instrumentation at Flagstaff Observatory, Melbourne in 1858. The instrument was used to determine the astronomical meridian, to be used as part of Neumayer's measurement of changes in the Earth's magnetic elements.
Physical Description
2 boxes: 1. stand and horizontal circle; 2. telescope and vertical circle.
More Information
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Collection Names
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Collecting Areas
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Acquisition Information
Transfer from Melbourne Observatory, 1945
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Maker
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User
Melbourne Observatory, South Yarra, Greater Melbourne, Victoria, Australia, post 1863
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User (Probable)
Flagstaff Observatory, Flagstaff Hill, Melbourne, Greater Melbourne, Victoria, Australia, 1858-1863
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User (Probable)
Georg Balthazar Neumayer - Flagstaff Observatory, Melbourne, Greater Melbourne, Victoria, Australia, 1858-1863
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Inscriptions
Telescope lens marked: 'Merz, Ulzschneider and Fraunhofer in Munchen'.
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Classification
Surveying & navigation, Optical - surveying, Angular measurement
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Category
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Discipline
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Type of item
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Overall Dimensions
63 cm (Length), 63 cm (Width), 63 cm (Height)
Dimensions will vary slightly depending how the theodlite is displayed relative to the wooden base.
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Dimensions
445 mm (Length), 445 mm (Width), 595 mm (Height)
Measurement From Conservation. Width and length are of the plinth to which the instrument is attached and not the instrument itself.
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References
George Neumayer, 'Description and System of Working of the Flagstaff Observatory,' Transactions Philosophical Institute of Victoria, v. 3, 1858.
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Keywords
