
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
1910-1923
1911
1917
1915-1918
1920
1914-1916
1913
circa 1915
1915-1918
1668; 1924
1610; 1923
circa 1923
circa 1925
1910
1915
1920
1915
1924
1910
1918
circa 1910
1914-1920
1910
1922
1915-1917
1913-1923
1916
1921
1914
1924
1915
1925
1912
1915
1910
1920-1925
1917
1910
1918
1912