
Obsidian possibly used in trephination experiments
1918-1920
1918-1920
1918
1952-3
1830 (original); 1967 (model)
circa 1919
1919
1923
1923
1917
1915-1918
1920
circa 1915
1915-1918
1668; 1924
1610; 1923
circa 1923
1915
1920
1915
1918
1922
1915-1917
1916
1921
1915
1915
1917
1918
1915
1922-1923
1922-1923
1921
1922-1923
1922-1923
1923
1915
circa 1920
1955; 1830
1918
1916-1917
1921
2000-100 BCE
1917-1918
1923
circa 1920
1920
1934
1915-1916
1903 (original); 1982 (model)
1772 (original); 1919 (model)