- Museum number
A Brass spy-glass of Galilean type with two original lenses that are covered by protective brass caps. Each element of the tubes is marked with a line and a notch to facilitate ease of observation. The spy-glass is kept within a brass case topped by a crown and signed on the base. This inner case fits within an outer case of tooled red leather over vellum lining.
- Production date
- 1620 (circa)
Length: 83 millimetres (brass case)
Length: 88 millimetres (leather case)
Length: 63 millimetres
- Curator's comments
For details and analysis of the lenses see Rolf Willach, The development of telescope optics in the middle of the seventeenth century, Annals of Science 58, 2001, 381-398.
A project led by Marvin Bolt (Adler Planetarium, Chicago) to compile a database of surviving telecopes made prior to 1775 is currently (2008) in progress, cf. http://historydb.adlerplanetarium.org/dioptrice
Ward 1981 445
Galilean spy-glass, diam 13 mm, with two protective glass caps. Objective diameter 12 mm; eye-lens opening diameter 4 1/2 mm. With brass case, length 82 mm, including a silver crown mounted on the lid; the bottom signed; 'Henr. Stolle. Vhrm. Prag fec'. Outer case of tooled red leather over vellum lining, diameter 25 mm, length 87 mm.
- Not on display
- Exhibition history
1997-2007: ‘A Glimpse of a Universe-Scientific Instruments from Renaissance Germany’ (British Museum, Gallery 44)
1997 30 May-7 Sep, Czech Republic, Prague, Prague Castle, Rudolph II and Prague
- Acquisition date
- Britain, Europe and Prehistory
- Registration number