Spherometer
1950-1975
Spherometer by Philip Harris Ltd.
1943-1983
Spherometer, 3-legged type
1875-1885
Spherometer, reads to 1/10
1845-1855
Spherometer and glass test plate in fitted wooden box
1870-1919
Spherometer
1920-1930
Spherometer
1920-1930
Spherometer, calibrated in dioptres
1900-1949
Spherometer in fitted case
1875-1918
Spherometer
1920-1930
Spherometer
1950-1975
Three microspherometers plus box of wire
Spherometer (1-inch radius) with case
1891
Spectacle lens measuring instrument
1900-1920
Sphermometer made by Harvey & Peak
circa 1900