who had expressed his concurrence so far as the naval portion of the scheme was concerned, and provided that the army made the necessary advance in Flanders.  When the scheme was shown to me shortly after taking office as First Sea Lord I confess that I had some doubts as to the possibility of manoeuvring two monitors, with a pontoon 550 feet in length secured ahead of and between the bows of the monitors, but in view of the immense importance of driving the Germans from the Belgian coast and the fact that this scheme, if practicable, promised to facilitate greatly such an operation, approval was given for the construction of a pontoon, and after witnessing the first trials of the pontoon secured between two monitors which were themselves lashed together, I became convinced that this part of the operation was perfectly feasible.  The remaining pontoons were therefore constructed, and preparations commenced in the greatest secrecy for the whole operation.

The next matter for trial was the arrangement devised by Sir R. Bacon for making it possible for tanks to mount the sea wall.  These trials were carried out with great secrecy against a model of the sea wall built at the Headquarters of the Tank Corps in France, and were quite successful.  It was necessary to see actual photographs of the tanks mounting the coping at the top of the sea wall to be convinced of the practicability of the scheme.  A matter of great importance was the necessity for obtaining accurate information of the slope of the beach at the projected landing places in order that the practicability of grounding the pontoon could be ascertained.  This information Sir R. Bacon, with his characteristic patience and ingenuity, obtained by means of aerial photographs taken at various states of tide.

Finally, to gain exact knowledge of the rise and fall of the tide, Admiral Bacon employed a submarine which submerged in the vicinity of Nieuport and registered the height of water above her hull for a period of twenty-four hours under conditions of spring and neap tides.

The preparations for the landing involved much collaboration with the military authorities, and Sir Reginald Bacon was frequently at G.H.Q. for the purpose.  As soon as it was decided that the 1st Division was to provide the landing party, conferences took place between Admiral Bacon and General Sir Henry Rawlinson (now Lord Rawlinson), and I took the opportunity of a visit paid by Sir H. Rawlinson to London to confer with him myself.  Subsequently a conference took place at the War Office at which Sir Douglas Haig was present.