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Speculum Metal Mirror, 1860
- Made:
- 1860 in Patricroft
- maker:
- James Hall Nasmyth

Speculum metal mirror, one of four, a concave circular-shaped secondary mirror for use at the Gregorian focus of the telescope, 1860. Mirror mounted on brass circular plate with threaded circular boss in centre.
Details
- Category:
- Astronomy
- Object Number:
- 1897-15/4
- Materials:
- speculum (alloy of copper and tin) and brass (copper, zinc alloy)
- Measurements:
-
overall: 20 mm x x , 46 mm, .225kg
- type:
- component, mirror, metal mirror and astronomical instrument
- credit:
- Lieutenant General A de Gorloff