"To keep the people at Fort Pickens from sending out any armed force," replied the intelligent contraband. "Do they think a boat full of men could do that?" "No, sir; but they could give the forts on the other side warning." The sounds from the boat had come from the starboard bow of the steamer, and it looked as though the guard-boat had intercepted her by accident, since it was impossible that they could have seen the Teaser in the fog and gloom. As the steamer dashed ahead at full speed, the sound of the oars came from a point on the beam. But the boat seemed to be wasting her time, for nothing had been done since the threat to fire into the steamer. "If a vessel is going to run out she has to satisfy this boat that she is all right," said Dave. But he had hardly spoken before a volley of musket-balls passed over the Teaser; and perhaps the officer in the boat intended that they should pass over her. At any rate no harm was done by them. Then a rocket darted from the boat up into the air, which could be dimly seen from the pilot-house. "What steamer is that?" shouted a hoarse voice out of the gloom. "The Teaser!" yelled Christy, with all the voice he could command. The boat did not fire again; and if it had done so the steamer was out of its reach. But a minute later the boom of a great gun came across the bay. Fort Barrancas had evidently opened fire in response to the rocket, which had no doubt been sent up as a signal to notify the garrison that a vessel was going out or coming in, and that her movements were not regular. The first shot was followed by others, and a shot dropped into the water near the Teaser. "Let the leadsmen sound, Beeks," said Christy. The order was repeated, and the reports were made known in the pilot-house. Sampson seemed to be testing the capacity of the engine, for he was doing his best in the matter of speed; but the Teaser behaved under the strain to which he subjected her as though she had been very strongly built. "By the mark eight," chimed the leadsman on the port side. That was water enough to float a seventy-four, and there was no let-up in the speed. In fact, it would not have been convenient to reduce the speed while the guard-boat could be at no great distance from the flying steamer. This was the report for the next mile at least, and Christy felt that the enemy was at a safe distance from him. "And a half six!" shouted the port leadsman, with energy, as though he understood the effect his report would produce. Christy rang to slow her down. The depth of water was the only directory he had in addition to the distance run, which was very indefinite without a knowledge of the speed of the vessel. "By the mark six!" shouted the port leadsman, who was on the side nearest to the island of Santa Rosa.