defeat the barrage was an important element. That submarines frequently crossed it is true ; there was no expectation, when the enterprise was started, that it would absolutely shut the U-boats in the North Sea ; but its influence in breaking down the German moral must have been great. To understand this, just place yourself for a moment in the position of a submarine crew. The width of this barrage ranged from fifteen to thirty-five miles; it took from one to three hours for a submarine to cross this area on the surface and from two to six hours under the surface. Not every square foot, it is true, had been mined ; there were certain gaps caused by the spontaneous explosions to which I have referred; but nobody knew where these openings were, or where a single mine was located. The officers and crews knew only that at any moment an explosion might send them to eternity. A strain of this sort is serious enough if it lasts only a few minutes; imagine being kept in this state of mind anywhere from one to six hours! Submarine prisoners constantly told us how they dreaded the mines; going through such a field, I suppose, was about the most disagreeable experience in this nerve-racking service. Our North Sea barrage began to show results almost immediately after our first planting. The German officers evidently kept informed of our progress and had a general idea of the territory which had been covered. For a considerable time a passage-way, sixty miles wide, was kept open for the Grand Fleet just east of the Orkney Islands; the result was that the submarines, which had hitherto usually skirted the Norwegian coast, now changed their route, and attempted to slip through the western passage-way—a course that enabled them to avoid the mine-field. When the entire distance from the Orkneys to Norway had been mined, however, it became impossible to "run around the end." The Germans were now obliged to sail boldly into this explosive field, taking their chances of hitting a mine. Stories of this barrage were circulated all over Germany; sailors who had been in contact with it related their experiences to their fellows; and the result was extremely demoralizing to the German submarine flotilla. The North Sea barrage was probably a contributory cause of the mutiny which demoralized the German fleet in the autumn of 1918.
I think I am therefore justified in saying that this enter-
