This book describes, on the first day of July, 1908, a scene which was destined to become historic took place in the great Lecture Theatre in the Imperial College at Potsdam. It was just a year and a few days after the swimming race between John Castellan and the Englishman in Clifden Bay. There were four people present. The doors were locked and guarded by two sentries outside. The German Emperor, Count Herold von Steinitz, Chancellor of the Empire, Field-Marshal Count Friedrich von Moltke, grandson of the great Organiser of Victory, and John Castellan, were standing round a great glass tank, twenty-five feet long, and fifteen broad, supported on a series of trestles. The tank was filled with water up to within about six inches of the upper edge. The depth was ten feet. A dozen models of battleships, cruisers and torpedo craft were floating on the surface of the water.