
Samples of polyethene, c. 1935.
1935
1935
1930-1960
1911
1921-1930
1934-10-23
1934-10-23
1934-10-23
1966
1775-1800
1930-1960
1920-1960
1957 (original); 1961 (model)
1941
1934-03-22
1964-08-31
1966
1966
1966
1966
1943
1960-1970
1920-1960
1920- 1960
1920-1960
1920-1960
1920-1960
1920-1960
1996
1968
1920-1950
before 1889
1993-1998
1994
1920-1960
1984
1969
1900-1980
1970
20th century
1920-1950
1920-1960
1920-1960
1982