Watt's end measuring machine
1776
1776
1794
1771-1800
1785
circa 1800
1776-1780
1776-1780
1776-1780
1778
1785
1785
1769
2000-100 BCE
1782-1793
1784
1770-1800
1778
1777-1785
1782
1787
hallmarked 1788
1770
1799
1796-1797
1796-1798
1775-1785
1785-1789
1771-1800
1783
1771-1800
1784
1785-1790
1798
1797
1781-1790
1780-1800
1790
1775-1795
circa 1780
1770
1775-1799 (original); 1900-1907 (model)
1797
1990-96
1771
1775
1788
1776-1780
1776-1780
1787
1783