Glancing at the dimly lit chart on the small table cunningly fitted into the front of the wheel-house, the commander noted the approximate position of the ship in the 140,000 square miles of sea and snow around, and then turning to the coxswain, whose "trick" it was at the wheel, he gave the necessary orders for the course and speed. The duty of this vessel was to patrol certain approaches to the great harbour on which the flotilla was based until relieved at daybreak by another unit, and, as merchant ships had many times been attacked in these waters, a sharp look-out was necessary. To carry this out effectively in the darkness and driving snow was a task calling for all the qualities of dogged endurance inherent in the British sailor. For over two hours nothing was seen or heard except the moaning of the wind and the lash of the sea, but shortly after midnight one of the look-outs reported the sound of engines away to the starboard. The M.L.'s propellers were stopped and the watch on deck listened intently. The splash of the sea and the many noises of a rolling ship drowned any other sound there might have been, and the patrol was then continued. Less than half-an-hour later, however, the clank! clank! clank! of engines again became suddenly audible, and the vessel was turned in the direction of the sound. The engines were put to full speed ahead, and as each comber struck the bows the little ship trembled from stem to stern, and clouds of icy spray swept high over the mast. The big steel hull of some man-o'-war or merchantman might suddenly loom up out of the darkness so close ahead that no skill could avoid a collision, and the eyes of all aboard were gazing alertly into the blackness of the night. Five minutes' dash through the blinding, stinging spray and the engines were once more shut off to listen. The curious clanking noise had, however, ceased, and although hydrophones were used to again locate the sound, there was no result, only the ceaseless wash of the sea and the low moaning of the wind. Another mile or so of pounding through the waves, followed by an interval of listening, brought the same discouraging result, and the slow, monotonous routine of patrol was continued. The stinging frost of the night became the numbing cold of early morning, and the long hours in the snow and icy spray had left their mark on all. Limbs were stiff and sore. The edges of wet and half-frozen sleeves rasped swollen wrists. Faces smarted and eyes ached, but little was said in the way of complaint, for men grow hard on northern seas or else succumb to the hardships. When the first dim light of a winter dawn broke reluctantly over the grey tumbling sea and whirling snow another night patrol was over, and the cheering thought came to all that soon the welcome warmth and shelter of club and recreation room would embrace them for the brief hours of daylight, while others kept watch upon the seas.