Subjects include: supplies in time of war; Canadian defence; measures to prevent blocking of commercial harbours; economic aspects of the Channel Tunnel scheme; the establishment of radio telegraphic communication between inland stations.

Subjects include: the Royal Flying Corps; coastal defences; defence of the Humber; the establishment of radiotelegraphic communication between inland stations; overseas attack; the Channel Tunnel scheme; support of customs and excise in the Orkneys, Shetlands and Scilly Islands in time of war; insurance of British shipping in time of war.

Subjects include: defence of St Helena; military aspects of the Channel Tunnel scheme; co-ordination of departmental action on the outbreak of war; the establishment of radiotelegraphic communication between inland stations; submarine cable communications; telegraphic communications; wireless communication with France; direct wireless communication with Russia; censorship of wireless messages in time of war; ambush mining and blockade mining.

Papers comprising diaries, correspondence, official papers, lectures, articles, broadcasts and photographs
Also including papers of Commander John Somerville about his father, 1950-91

Mainly concerning wireless telegraphy.

Subjects include: shipbuilding figures; wireless policy; squadrons abroad for trade protection; totals of ships sunk by German submarines and losses among German and Turkish submarines; the speed and armaments of German submarines; the need to simplify correspondence between the Admiralty and the dockyards; possible zeppelin attacks on London; steady pressure strategy.