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