us the loss of a small coaster turned temporarily into a man-of-war was of little consequence. A similar ship, the _Suffolk Coast_, would soon be picked up and then turned over to the dockyard experts to be fitted out; but in the case of a submarine there were only limited numbers. That particular U-boat would now have a long list of defects and be a non-combatant for a long time, and her crew would morally be seriously affected by their miraculous escape, and they would not forget to pass on their impressions to their opposite numbers in other submarines. It was rather the cumulative effect of Q-ships, destroyers, mines, auxiliary patrol craft, depth charges, hydrophones, convoys, and good staff work which broke the spirit of the German submarine menace, so that if the war had continued much longer U-boats would have been thwarted except within certain limits of the North Sea. Every weapon has its rise and fall in the sphere of usefulness; the shell is repelled by armour-plate, the Zeppelin is destroyed by the aircraft, and so on. So it was with the Q-ship. It came into being at a time when no other method seemed likely to deal with submarines adequately. It became successful, it rose into popularity to its logical peak, and then began to wane in usefulness as the submarine re-adapted herself to these new conditions. Afterwards came the period when the mine barrages in the Heligoland Bight, in the Dover Strait, and across the northern end of the North Sea, and the hydrophones, in swiftly moving light craft, made the life of any submarine precarious in his going and coming. The hydrophone has made such wonderful developments since the war that in the future within the narrow seas a submarine would find life a little too thrilling to be pleasant.