Watt's end measuring machine
1776
1776
1808
1809
1794
1795-1805 (original)
circa 1805
1771-1800
1760-1770
1797-1804
1785
circa 1800
1776-1780
1776-1780
1776-1780
1793-1803
1806
1769
1807
1795-1805
1784
1762
1762
1770-1800
1782
1787
hallmarked 1788
1770
1799
1795-1810
1796-1797
1796-1798
1790-1810
1775-1785
1785-1789
1762
1762
1761
1762
1762
1762
1762
1762
1781-1790
circa 1810
1780-1800
1778
1783
1785
1785
1765-1806