
Original laboratory sample of 'M and B 693', England, 1938
1938
1938
1834-1836
1927-1928
1610; 1923
1956
1939-1945
700 BCE; 1931
1928
6000-5000BCE
1930s
circa 1923
1879 (1956)
1933
1950-1954
1940-1945
1949
1933
1949
1949
1952
1937
1944
1940
1929
circa 1956
1925-1955
1925-1935
1932
1960-1979
1940
1945-1952
1937
1932
1936
circa 1953
1950-1954
1985-11
1955
1925; 1862
1930-1935
1934
1925-1935
1950-1955
1925
circa 1930
1923-07
circa 1935
1979-80
1931
1942-1950