Thus to all outward appearance this performance was merely the torpedoing of a helpless merchant vessel. Yet the average German commander became altogether too wary to accept the situation in that light. He had no intention of approaching either lifeboats or the ship until entirely satisfied that he was not dealing with one of the decoy vessels which he so greatly feared. There was only one way of satisfying himself: that was to shell the ship so mercilessly that, in his opinion, if any human beings had remained aboard, they would have been killed or forced to surrender. The submarine therefore arose at a distance of two or three miles. Possibly the mystery ship, with one well-aimed shot, might hit the submarine at this distance, but the chances were altogether against her. To fire such a shot, of course, would immediately betray the fact that a gun crew still remained on board, and that the vessel was a mystery ship; and on this discovery the submarine would submerge, approach the vessel under water, and give her one or two more torpedoes. No, whatever the temptation, the crew must "play 'possum," and not by so much as a wink let the submarine know that there was any living thing on board. But this experience demanded heroism that almost approaches the sublime. The gun crews lay prone beside their guns, waiting the word of command to fire; the captain lay on the screened bridge, watching the whole proceeding through a peephole, with voice tubes near at hand with which he could constantly talk to his men. They maintained these positions sometimes for hours, never lifting a finger in defence, while the submarine, at a safe distance, showered hundreds of shells upon the ship. These horrible missiles would shriek above their heads; they would land on the decks, constantly wounding the men, sometimes killing whole gun crews--yet, although the ship might become a mass of blood and broken fragments of human bodies, the survivors would lie low, waiting, with infinite patience, until the critical moment arrived. This was the way they took to persuade the submarine that their ship was what it pretended to be, a tramp, that there was nothing alive on board, and that it could safely come near. The still cautious German, after an hour or so of this kind of execution, would submerge and approach within a few hundred yards. All that the watchful eye at the peephole could see, however, was the periscope; this would sail all around the vessel, sometimes at a distance of fifty or a hundred feet. Clearly the German was taking no chances; he was examining his victim inch by inch, looking for the slightest sign that the vessel was a decoy. All this time the captain and crew were lying taut, holding their breath, not moving a muscle, hardly winking an eyelid, the captain with his mouth at the voice pipe ready to give the order to let the false works drop the moment the submarine emerged, the gun crews ready to fire at a second's warning.