Visitors' Book for the Metropolitan-Vickers Electrical Company Limited Research Department, recording visits made to the laboratories in Trafford Park, including the signatures of Ernest Rutherford, T E Allibone (attending the opening of the High Voltage Laboratory in 1930), King George VI, the Earl of Derby (visiting in 1931), Douglas Hartree (visiting in 1932), R J Van de Graaff (visiting in 1933), John Cockcroft (visiting in 1937) and Anthony Eden (representing the Foreign Office in 1941).