Image splitting eyepiece by Vickers
1960-1969
1960-1969
1918-1960
1927
1960-1969
1961-1975 (estimated)
1966-1979
1964-1978
1880
1843
1950-1959 (estimated)
circa 1920-1939
1890
1953
1961-1975 (estimated)
1959-1969
1947
1960-1980
1998
1960-1969
1950-1959
circa 1956
1931-1939
1954-1964
1967
1956
1955-1964 (estimated)
1950-1959 (estimated)
1970-1979 (estimated)
1971-1980
1985-1994
1998
circa 1971
1999
1970-1979
1908-1914 (estimated)
1975 (original)
1999-2000
1875-1924 (estimated)
1980-1984
1976-1985
circa 1920-1939
1974
1965-1974
1965-1974 (estimated)