Abbe-type refractometer by Carl Zeiss of Jena
1900
1900
1910-1920
1998
circa 1912
1956
1948
1950-1975
1918-1920
1930
1900-1950
1899-1950
1950-1975
circa 1923
1880-1910
1870-1940
1898
1880-1910
1880-1910
1975-1982
1870-1893
1876
1998
1898
1870-1893
1998
1900
1930-1939
1998
1920-1929
1951-1960
1880-1910
1997