Watt's end measuring machine
1776
1776
1785
1776-1780
1776-1780
1776-1780
1778
1785
1785
1769
2000-100 BCE
1784
1778
1777-1785
1782
1787
hallmarked 1788
1770
1775-1785
1783
1784
circa 1780
1770
1990-96
1771
1775
1788
1776-1780
1776-1780
1787
1783
1705-1737
1785
1780
1772 (original); 1919 (model)
4000-2001 BCE
1775-1785
1784
1784
1783
1784
1769
1775
1772-1773
1776
1778-1780
1785
1769
1773
1774
1771-1780