
Obsidian possibly used in trephination experiments
1918-1920
1918-1920
1918
1919
1915-1918
1952-3
1917
1914-1918
1830 (original); 1967 (model)
1913
circa 1915
1914-1918
1839 (original); circa 1988 (replica)
1911
1913
1919
1919
1921
1668; 1924
1921
circa 1919
circa 1920
1920
1914-1916
1990-96
1610; 1923
1914-1918
1772 (original); 1919 (model)
1921
2000-100 BCE
1917-1918
circa 1917
1925; 1862
1902; 1913-1920
circa 1916
1911
1915
1917-1918
1915
1915-1920
c.1912
1914-1918
1990-95
circa 1912
1934
c.1912
1914-1918
1920
1913
1914-1918
1920