Model ground signal, North London Railway
1888
1888
1890
1910
1910
circa 1900
1903
1902
1850-1900
1850-1909
circa 1880
1900
1875
1884
1860
1910
1850
1901
circa 1885
1910
1896
1912
1914
1895
1896
1851
1906
1902
1910
1898
1901
circa 1871
1853
1870-1910
1857
1875
1896
circa 1905
1886
1906
1860
1911
1850-1900
1889
circa 1900
1898
1899
1850-1856
1901
1901
1855-1860