
Clarke's Hydrometer (c. 1755)
1755
1755
1762
1762
1757
1761
1762
1762
1761
1762
1762
1762
1762
1755
1762
1755
1755
1762
1760
2000-100 BCE
1765
1761
1705-1737
1761
1761
1762
1762
1762
1763
1761
1761
1761
1761
1755
1755
1761-1762
1760
1755
4000-2001 BCE
1668; 1924
1990-95
1610; 1923
1642-1649 (original); 1883 (model)
1936
circa 3000 BCE
100 BCE-300 CE; 1890-1920
2000-1350
1972-3
2000-1000
1755
circa 1800 BCE