"By the condition of the floats," answered the captain. "You will notice that the two floats within range of the submarine's action are being dragged down. If the floats should be in a normal condition, or float on their true water line, which you can readily observe by glasses, it is evident that the submarine is free." "And then that would be the time they would use the howitzers?" suggested Alfred. "But how could they reach the submarine?" asked Ralph. "Do they know just where the vessel is now?" "Yes, they can locate it within a hundred feet; but that would be near enough for their purpose," replied the captain. "Do you mean," asked Alfred, "that they would send the shell from the howitzer anywhere near them, and that it would destroy the submarine even though it didn't hit it?" "Yes; the detonating or rupturing effect of the high explosive in the shells is such that even though the explosion would take place a hundred feet from the hull, it would put it out of commission at once, and, in all probability, crush in the sides like an egg shell," said the captain. "Why are they signaling?" asked Ralph, as the wig-wagging began. "I think that's _l'Orient_ in sight on the port side," replied the captain, after gazing in the direction indicated. "Then the cruiser will take the position of the chaser?" said Alfred. "Quite likely," answered the captain. "Look at the smoke; she's coming this way," shouted Ralph. The captain waved his hand to the lieutenant on the chaser, as he shouted: "They have responded to your signals." As _l'Orient_ approached and took up position, the chaser, with a parting salute, turned and started for its former course along the line of buoys. The boys looked back and kept their eyes on the moving buoys as far as they could see them. "It will never get away," said the captain. The chaser described a long curve, and changed its course due east, and, following it, they were at the entrance which had been left free. Beyond were several other small vessels, two of which dashed up and steamed alongside. The crews cheered as the boys emerged from the conning tower and waved their caps. The lieutenant quickly informed the officers aboard the other boats of the prize, which had been taken by those aboard of her, and the news redoubled their noisy welcome. The tell-tale number on the side of the conning tower, U-96, was sufficient to inform the crews of the passing vessels that another of the dreaded boats was out of action. Once within the lane, as the path between the two lines of buoyed nets is called, they turned and steamed north. Vessels were passing and repassing; transport and hospital ships; immense freight carriers, and saucy little tugs drawing barge-like flat-boats; innumerable fast launches and large war vessels, going to and fro between the shores of England and France.