The collection consists of manuscripts relating to the history of signalling, 1781 to 1914. The printed part of the original collection, also to 1914, is in the Library. The manuscripts include sixteen late eighteenth- and early nineteenth-century signal books; a book of codes for use with an electric telegraph, 1855; correspondence concerning the rules for the use of wireless telegraphy, 1893; correspondence and photographs relating to the development of communication by flashing signals, 1861 to 1893, 1904; a collection of annual reports on the Naval Pigeon Service, 1903 to 1908; proposed Forming, Disposing and Stationing Signals, 1890 and 1892; correspondence on Equal and Unequal speed manoeuvres, 1891 to 1892, and on Battle Tactic Signals, 1901. Foremost among the correspondents on these and other subjects is the first Superintendent of the Signal School, Admiral A.F. Everett (1868-1938).

Administrative / biographical background
The Naval Signal School, known as H.M.S. Mercury since 1941, was founded at Portsmouth in 1901. In 1942 the school was moved to East Meon, near Petersfield, Hampshire.