Torsion balance to weigh up to 100 mg made by White Electical Instrument Co
circa 1950
circa 1950
1881-1926
1926
1900-1910
1950-1960
1926
1915-1925
1926
1900-1930
1926
1926
1880-1930
Early 1900s
circa 1910
1889
1926
1900-1930
circa 1950
1889
1915-1925
1926
1918-1949
1900-1980
1926
1926
1889
1889
1889
1926-1940
1900-1980
1896-1918
1945-1980
1920-1960
1920-1970
1889
1889
1889
1889
1900-1926
1860-1980
1930-1965
1860-1980
1860-1980
1889
1889
1889
1910
1926
1925-1930