Clarke's Export Hydrometer (dated 1815) by DRING & FAGE
1815
1815
1755
1850-1860
1885-1936
1875-1900
1830
1873
1816-1873
1780-1790
1920-1930
1801-1820
1830-1900
1930
1870-1940
1781
1810-1830
1896
circa 1823
1740-1800
1961
1840
1940-1950
late 19th century
1870-1930
1920- 1960
1945-1954
1903-1938
1894-1930
1815-1825
1870-1930
1860
1870-1880
1871-1900