Accession No
2135
Brief Description
altazimuth instrument, by Ertel & Sohn and Utzschneider & Fraunhofer, German, c.1840
Origin
Germany; Munich
Maker
Ertel & Sohn Utzschneider & Fraunhofer
Class
astronomy
Earliest Date
1840
Latest Date
1840
Inscription Date
Material
metal (brass, steel, silver); glass
Dimensions
length 385mm; breadth 360mm; height 350mm
Special Collection
Provenance
Transferred from Institute of Astronomy, University of Cambridge, Cambridge, England, 10/1975. Bought by Adams for Cambridge Observatory, 1866 (see file). Made by Ertel for E.J. Cooper at Markree (see history file).
Inscription
‘Ertel & Sohn in München’ (stand)
‘Utzschneider u. Fraunhofer in München’ (objective end)
Description Notes
‘Broken’ (axis view) altazimuth instrument. Brass telescope with object glass cover, 2 counterweights. Brass axis with steel bearings. Two vertical brass circles with silvered scales, one divided 0 - 360˚, subdivided to 1˚, to 30´ and to 10´, with 4 verniers (numbered I - IV) on inner circle, 4 reading microscopes and bubble level. The other divided 0 - 360˚, subdivided to 1˚, to 30´ and to 15´, one vernier on stand and one reading glass on hinged arm. Clamp. Zero adjustment for inner circle. Brass Ys with brass pillars. Inner spoked wheel with 4 silvered verniers (numbered I - IV) and 3 reading microscopes (mount for another but microscope missing), pivots within outer brass circle with silvered scale divided 0 - 360˚, subdivided to 1˚, to 30´ and to 10´. Mounted on spoked circular base with three levelling screws, divided 0 - 100 by 1, each with clamping screw. Eyepiece missing.
Condition
References
Events
Description
An altazimuth instrument is a telescope set on a mounting that can be moved both horizontally and vertically. It needs to be adjusted in both directions of movement at the same time in order to follow a star across the sky. It allows you to measure the position of a celestial object in altitude (height in the sky) and azimuth (degrees horizontally from north).
Nineteenth-century altazimuth telescopes were often small portable instruments. This telescope was made in Munich around 1840 and was used in the observatory at Castle Markree, County Sligo, Ireland, described by the Royal Astronomical Society in 1851 as the most richly furnished private observatory in existence. The Cambridge Observatory acquired it in 1866.
02/05/2008
Created by: Dr. Jenny Downes on 02/05/2008
FM:44687
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