Spectacle lens measuring instrument

'Spherometre' a type of sperometer used to measure the convex and concave shape of spectacle ophthalmic lenses, signed 'G. L.', French, 1900-1920. Dial scale graduated in dioptres (dioptrice) & inches (pouce) and marked as patented (Brevete S.G.D.G.).

Details

Category:
Optics
Object Number:
1952-317
Materials:
metal plated (unknown), glass and paper (fibre product)
Measurements:
overall (upright): 108 mm x 63 mm x 40 mm, .177kg
type:
spherometer
credit:
Clay, R.S.