![](https://coimages.sciencemuseumgroup.org.uk/521/324/large_thumbnail_smg00307890.jpg)
Astatic Current Indicator (No 615) marked 'Crompton's patent' maded by R E Crompton & Co
circa 1878-1927
circa 1878-1927
1940-1960
1799-1870
1831-1940
1880-1885
1896-1925
1851-1894
1880-1920
1927
1965-1975
Unknown date
1930-40
1959
1888-1901
1895-1900
1914-1934
1830-1900
1950-1955
2020-2023
2020-2023
2015
1901-1930
1850-1900
1803-1876
1921
1959
1860-1920
1900-1935
1960-1969
1828-1860
1937
1950-1980
1970
1898-1935
1930-1931
1950-1955
1831-1870
2020-2023
1968
2016