In a convoy the troop or merchant vessels sailed in echelon formation with destroyers or cruisers steaming in front and at the rear while a destroyer ranged in zig-zag course along each side. Naval gun crews manned each ship and on each one, in addition to the watches kept on board the escorting vessels, keen eyes constantly swept the surrounding waters, every moment of the day and night. At night all lights were dimmed, so that not a ray of even a lighted match on deck was ever visible, and the great black hulks rushed onward through the darkness, never knowing at what moment they might collide with one another or with one of the escorting vessels. But so skillfully navigated were they that all such dangers, though they were very real, were escaped. No greater feat was achieved by our fighting forces than this of ferrying across the Atlantic an army of 2,000,000 troops, with their food, equipment, and munitions, and the material necessary in enormous amounts for the creating and carrying on of the Service of Supply. It was an arresting achievement not only because of its unparalleled bigness and its audacity and success but also because of its vital importance. Without it the war could not have been won. And the credit for the achievement belongs to the American Navy. Our co-belligerents gave vitally important aid. But the American Navy suggested, developed, organized, supervised, operated and was responsible for the entire huge system. Into its success went many factors, not the least of them the foresight and watchfulness and careful planning of the officials of the Navy, from the Secretary down to the junior officers on the troop ships. There was constant study of the submarine peril and of means to lessen it, and it was, by autumn of 1918, almost eliminated by the combined efforts of the associated nations. There were the zeal and diligence of officers and crew alike and the consequent high morale, the skill of the gun crews, who never ceased from the effort to make it better still by daily target practice, and that constant attention to detail which leaves no loophole anywhere through which success might dribble and slide away. And finally there were the skill, courage, devotion and audacious spirit of the naval officers whose ships escorted the convoys back and forth across the ocean. All these and other factors combined to make possible an achievement that stands out commandingly even in a war compact of big things and huge achievements. [Illustration: _By Permission of Mid-Week Pictorial, New York Times Co._ MINE BARRAGE ACROSS THE NORTH SEA] CHAPTER XI WORKING WITH THE ALLIED NAVIES