
Obsidian possibly used in trephination experiments
1918-1920
1918-1920
1917
1919
circa 1915
1920 - 2007
circa 1920
1915
1920
1915
1918
1916
1915
1915
1917
1918
1955; 1830
1915-1917
1918
1918
1915-1918
1916-1917
1915
1934
1920
2000-100 BCE
circa 1920
1915
1920
1917-1918
1920
1920
1920
1903 (original); 1982 (model)
1772 (original); 1919 (model)
1990-96
circa 1920
1830 (original); 1967 (model)
1952-3
circa 1920
1839 (original); circa 1988 (replica)
1930 (replica); 1834 (original)
1919
1915
1916
1915-1920
1916-1918
1705-1737
1801-1892 (prepared); 1946 (element replaced)
1918
1917