
Experimental transmitting ‘jigger’ used by the Marconi Company, 1899
1899
1899
1865
1857-1858
1851-1900
1870-1890
1886
1854
1830-1900
1880-1900
1836
1850-1900
1821-1850
1750-1800
1855
1767
1871
circa 1880
1771-1860
1801-1900
1787
1801-1900
1880-1899
1822-1875
1750-1800
1890 - 1900
1770-1900
1820-1830
1750-1766
1830-1900
1770
1765-1806
circa 1854
1760-1820
1850-1900
1780-1860
1801-1900
circa 1860
1801-1900
1850
circa 1850
1854
1875-1877
1785
1775-1795
1871-1900
1897
1760-1775 probable date
1864
1830
1878