
Obsidian possibly used in trephination experiments
1918-1920
1918-1920
1918
1920-1925
1952-3
1830 (original); 1967 (model)
circa 1919
1915-1925
1919
1923
1923
1917
1915-1918
1920
1914-1916
circa 1915
1915-1918
1668; 1924
1610; 1923
circa 1923
circa 1925
1915
1920
1915
1924
1918
1914-1920
1922
1915-1917
1916
1921
1914
1924
1915
1925
1915
1920-1925
1917
1918
1925
1915
1922-1923
1922-1923
1921
1922-1923
1922-1923
1925
1923
1915
circa 1920
1914-1918