Experimental speculum of 6 inches aperture and 24 inches focal distance

Experimental speculum of 6 inches aperture and 24 inches focal distance, cracked across and bound together with string

Details

Category:
Astronomy
Object Number:
1876-564
Materials:
speculum metal (bronze alloy)
Measurements:
overall: 70 x 180 mm
type:
components, concave mirrors, metal mirrors and astronomical instruments
credit:
Lord Rosse (4th Earl)