Watt's end measuring machine
1776
1776
1808
1809
1794
1795-1805 (original)
1808
circa 1805
1771-1800
1797-1804
1785
circa 1800
1776-1780
1776-1780
1776-1780
1793-1803
1778
1785
1785
1806
1807
2000-100 BCE
1782-1793
1795-1805
1784
1893-4
1799-1802
1863-7
1770-1800
1778
1777-1785
1782
1787
hallmarked 1788
1770
1799
1795-1810
1802
1805
1796-1797
1796-1798
1790-1810
1775-1785
1785-1789
1771-1800
1807
1783
1771-1800
1784
1785-1790
1798