Owing to the continual current down the Dardanelles, it occurred to the minds of the German officers serving with the Turkish forces to set adrift numbers of floating mines. These formidable engines of destruction were launched from the southern outlet of the Sea of Marmora, while to make the chances of their fouling a ship doubly certain they were released in pairs, each couple being connected by fifty or a hundred feet of wire. The bight of the wire getting caught across the bows of a ship would result in the mines swinging inwards and exploding upon contact with the vessel's sides. Wisely the British Admiral ordered a retirement, until steps could be taken to cope with this latest scheme of defence on the part of the enemy, and as night fell the fleet steamed towards its anchorage. The weather was now beginning to change back to a spell of hard winds and rain, which in itself would cause a temporary suspension of operations, and the officers and men of the fleet had to face the dismal prospect of "standing by" instead of returning to the attack with renewed zest and animated by a desire to revenge their losses. Dick was just about to sit down to a hasty meal--it was his first opportunity of doing so since the _Hammerer_ went into action that morning--when the "Officers' Call" was sounded. "Now what's in the wind?" he mentally enquired as he dashed on deck. The Sub was not kept long in doubt. A message had been received from the flagship stating that one of the mine-sweepers, the _St. Rollo_, had gone ashore at Yenikeui on the Asiatic shore, and about six miles SW. by S. of Kum Kale. The _Hammerer_ and the _Tremendous_ were asked for volunteers to attempt the rescue of the crew. It was expressly stated that, owing to the shoaling nature of the coast at the point, gigs or whalers must be employed, but a destroyer would be cruising in the vicinity to pick up the rescue parties on their return. It was taken for granted that the business was a dangerous one, otherwise the boats would be ordered to proceed to the spot. The mere fact that volunteers were asked was in itself significant. Not only was there grave risk of being fired upon by the Turkish troops, who doubtless would muster in force at the spot where the mine-sweeper grounded, but it was now a pitch-dark night with a falling glass and a rising sea. "What boats have we fit for service, Mr. Box?" the Captain, addressing the carpenter. The warrant-officer had the information at his fingers' ends, for, as soon as the _Hammerer_ had drawn out of range, one of the first of many tasks of the carpenter's crew was to set to work and patch up the boats that were most capable of being made seaworthy again. "Now, gentlemen," continued the owner. "You know what is required and the condition of the boats. Who will volunteer?" Almost all the executive officers and every one of the midshipmen signified their willingness to answer the call for aid.