The inventive ingenuity of the American people was apparently much attracted towards the problems of sea warfare in this conflict, for they began to send ideas, suggestions and devices to the Navy Department even before the United States became a belligerent. After that date the Consulting Board of the Navy, which has charge of such matters, was almost snowed under by these suggestions. During our participation in the war the Board examined and acted upon 110,000 letters, of which many included detailed plans or were accompanied by models of the contrivances which their writers hoped to have adopted. Most of them were either worthless or already known, but a comparatively small number were found valuable. At the beginning of our war activities our naval roster listed over 65,000 officers and men, with 14,000 more in the Marine Corps. A year and a half later the Marines numbered 70,000 and in the Navy there were a little more than 497,000 men and women, for a goodly number of patriotic women had enlisted in order to undertake the duties of yeomen and so release able bodied men for active service. The total permanent personnel of the Navy, officers and men, had grown to 212,000. This rapid expansion had made necessary intensive training for both men and officers that was carried on with never ceasing activity at training stations on shore and on ships at sea in both home and foreign waters. In small-arms training alone a force of 5,000 expert instructors was built up who trained an average of 30,000 men per month. How all this immense expansion in ships, men, stores, facilities and production measures against the previous history of the Navy appears in this fact: In the almost century and quarter since the Navy was established in 1794 until and including 1916 its expenditures totaled, in round numbers, $3,367,000,000, an amount which exceeded its expenditures in the next two years alone by only $34,000,000. [Illustration: CONVOY OF TROOP SHIPS ENTERING THE HARBOR OF BREST] CHAPTER X OPERATING AN OCEAN FERRY The United States had to carry on its share in the war from a base three thousand miles distant from the battle zone and to transport troops, munitions, supplies across an ocean infested by submarines intent upon sinking as many of them as possible. It was a task so unprecedented and so difficult that before it was attempted it would have been thought, in the dimensions it finally assumed, utterly impossible. The enemy was so sure it was impossible that he staked all his hopes and plans upon its failure.