Silently the warships steamed for the mouth of the harbor, and took up their various positions in a grand semicircle, the heavy fighting ships in the centre, and the torpedo boats on the ends, ready to take care of any infantry fire, should the Spaniards hurry their soldiers to the shore. The big ships kept at a distance of three thousand yards--not quite two miles. "We're a long way off," observed Walter, as he assisted in loading the "Polly," as Caleb had named his gun. "Twenty-nine hundred yards!" came the report from the range-finder; and the crew went to work to elevate the gun accordingly. In the meantime, the magazines had been opened, the ammunition hoists set in motion, and powder, shot, and shell were delivered everywhere from barbette to fighting-top. "We're near enough to blow 'em sky-high if we strike 'em right," muttered the old gunner, who, with the smell of powder in the air, was in his element. "How about that hose, Stuben?" he went on to the hose-man. "Dot hose it's all right alretty," answered Carl Stuben, a round-faced German, who was an American citizen, even though he did speak the language but brokenly. Heretofore Walter had had but little to do with the man, yet they got along very well together. It was too dark to begin firing, and for half an hour the ships lay quiet, every man ready to obey a command the instant it was given. This was a nerve-trying test for Walter, who wondered how the thing would sound when all of the ships began firing. Slowly it grew lighter, and the men became more anxious. The guns were trained on the shore batteries to the west of the harbor entrance, while other ships covered the batteries on the east. Boom! It was a broadside from the _New York_, directed against the battery below El Morro. Instantly every other warship present responded in a deafening crash and a shock to be heard many miles away. At once the air became filled with the smoke, and on shore the dirt and masonry of the batteries were seen to fly in all directions. "Oh, my!" gasped Walter, as the gun before him belched forth its mass of flame and smoke. "What a noise! Did--did we hit anything?" "I hope we did," answered Steve Colton, the second gun captain, laconically; and then came the order to unlock the breech of the gun. As the breech fell back a cloud of smoke swirled into the sponson hood, impregnated with the odor of saltpetre, which caused Walter and several of the others to cough violently. "Never mind; you'll get used to it before you die," went on Colton.