
Obsidian possibly used in trephination experiments
1918-1920
1918-1920
1903
1901-1920
1903
1918
1920-1925
1900-1910
1901-1930
1952-3
1905
1830 (original); 1967 (model)
circa 1919
1915-1925
circa 1900
1898
1919
1928
1923
1801-1840 (original); 1901 (model)
1923
1901-1930
1900-1920
1910-1923
1911
1927
1917
1902
1926
1901-1910
1899-1919
1915-1918
1920
1914-1916
1909-1910
1913
circa 1900
1927
1900-1920
circa 1915
1775-1799 (original); 1900-1907 (model)
1901-1920
1915-1918
1668; 1924
1930
1610; 1923
circa 1923
circa 1925
1907
1899 - 1993
1926