
Obsidian possibly used in trephination experiments
1918-1920
1918-1920
1903
1901-1920
1903
1918
1920-1925
1900-1910
1952-3
circa 1919
1905
1915-1925
1830 (original); 1967 (model)
circa 1900
1898
1919
circa 1897
1900-1920
1897-1898
1923
1801-1840 (original); 1901 (model)
1910-1923
1914-1916
1911
1917
1902
1896
1895-1905
1901-1910
1920
1890-1900
1915-1918
1896-1920
1899-1919
1909-1910
1901-1920
1775-1799 (original); 1900-1907 (model)
1913
circa 1900
1900-1920
circa 1915
1895-1905
1915-1918
1895-1905
1668; 1924
1890
1892
1610; 1923
circa 1925
circa 1923
1907