Mention has been made of the development of aircraft during the War. The possibilities resulting from the use of the air for reconnaissance work, for assisting in the direction of gunfire, and, finally, for offensive operations, were fully recognised in the Grand Fleet; but for a considerable period the lack of suitable machines hindered development. The first decisive step taken was the fitting out of the _Campania_, a passenger ship of the Cunard Line, as a sea-plane carrier to be attached to the Battle Fleet. Prior to that, the Harwich Force and, later, the Battle Cruiser Fleet had been provided with smaller vessels, the _Vindex_ and _Engadine_, carrying a few sea-planes. They had been used in operations in the Heligoland Bight, but without much success, owing to the difficulty experienced in getting sea-planes to rise from the water except in the finest weather. With the arrival of the _Campania_ at Scapa, we were able to investigate the difficulties attending the use of aircraft from ships as then fitted and to indicate the direction in which improvement was desirable and possible. It was apparent that little improvement could be expected so long as we were dependent on the machines rising from the water. The first step, therefore, was to improve the arrangements for flying off from the deck of the _Campania_. The ship returned to Liverpool at the end of 1915 in order that the necessary alterations might be effected; these were not completed until the late spring of 1916; during the alterations, the _Campania_ was also, at my request, fitted to carry a kite balloon. The advantages to be obtained from the use of kite balloons had been demonstrated during the Dardanelles operations, and the _Menelaus_, kite balloon ship, was sent to the Grand Fleet. But it was soon obvious that we could not make profitable use of kite balloons in a fleet action unless they were flown from the ships themselves, and experiments were carried out, under the direction of Vice-Admiral Sir Doveton Sturdee, commanding the 4th Battle Squadron, having as their object the best method of fitting and using kite balloons from warships. Many difficulties were experienced, the principal one being that of providing wire of sufficient strength to stand the tension of the balloon during strong winds. The Kite Balloon Section at Roehampton gradually solved the difficulties, and by the end of 1916 the majority of the flagships leading divisions of the Fleet were provided with kite balloons, and were experiencing their utility. From this beginning, great developments took place in providing vessels of all classes, including light cruisers, destroyers, P boats, and trawlers, with kite balloons; the balloon was used in the case of the smaller vessels for anti-submarine reconnaissance work, whilst in the heavy ships it was used for observation and correction of fire.