
Oertling microbalance model 146 with white metal beam and brass upright and cylindrical air dampers
1965
1965
1929
1953
1959-1960
1955
1949
1941
1931-1970
1940-1950
1931-1970
1925
1920-1927
1939
1954
1964
1951
1970
1931-1970
circa 1876
1979
1959
1947
1903
May 1954
1951
1949
1955