Clarke's Export Hydrometer (dated 1815) by DRING & FAGE
1815
1815
1831-1870
1873
1816-1873
1961
1860-1870
1876
1801-1900
1903-1938
1878-1882
1860
1815-1825
1804-1844
1804-1844
1825-1835
1865-1875
1840-1920
1876
1940-1950
1860
1830
1792
1851-1900
1813
1820
circa 1950
1900-1950
1900-1950
1840-1850
1887 patent
1815-1825
1855-1865
1900-1950
1850-1860
1903-1910
1900-1905
1820-1860
1830-1880
1867