Double surface of revolution of constant negative curvature
1910
1910
1910
circa 1910
1934
1909
1910
2000-100 BCE
1872 (original); 1909 (model)
1955; 1830
1910
1910
1990-96
1934
1930 (replica); 1834 (original)
1801-1892 (prepared); 1946 (element replaced)
1705-1737
1903 (original); 1982 (model)
1772 (original); 1919 (model)
1830 (original); 1967 (model)
4000-2001 BCE
1909
1909-1910
1910
1910
1971-1900
1909-1910
1909-1910
1909-1910
1909-1910
1909-1910
1909-1910
1909
1909
1909
1910
1909
1909
1909
1909
1909
2000-1350
1910
1910
circa 1920; 1907
1972-3
1945-50
1910
1990-95
1909
1910