Jeffreys respirator for the relief of lung disorders
1836-1900
1836-1900
1814-1815
1939-1945
1750-1850
1910-1920
1970-1985
1888-1932
1900-1910
1750-1850
1967
undated
1930-1943
1901-1930
1880-1890
1915-1918
1969-1970
1920-1940
1801-1900
1955-1960