The trip this far has been a constant succession of drills and instruction in the art of submarine fighting—all to the tune of general alarm and torpedo defense bells. And the while preparations for sighting the enemy have never been minimized. They involved precautions not dissimilar to those on board a destroyer or other patrol-vessel, but were of course conducted on a vastly greater scale. As suggesting an outline of measures of watchfulness, we may regard this battleship as the centre of a pie, with special watches detailed to cover their given slice of this pie. These slices are called water sectors, and each sector, or slice, extends at a given angle from the course of the ship out to the horizon. Of course as the vessel is constantly moving at a rapid rate, the centre of the pie shifts, too. In this way every foot of water within the great circle of the horizon is under constant supervision night and day by a small army of lookouts, armed with binoculars and gun telescopes.
And so our battleship goes on through the night. On the bridge all is quiet. Officers move to and fro with padded footfalls, and the throb of the great engines is felt rather than heard. The wind begins to change, and presently the captain glancing out the door of the chart-house clucks his chagrin. For the night has begun to reveal itself, thanks, or rather, no thanks, to the moon, which has torn away from a shrouding mass of clouds and sends its rays down upon the waters of the sea. It had been a fine night to dodge the lurking submarine, but now the silver light of the moon, falling upon the leaden side of the battleship, converts her into a fine target.
"Nature is certainly good to the Germans," chuckles an officer to a companion, taking care that the captain does not hear.
"Yes," comes the sententious reply. The lookouts grow more rigid, for whereas formerly they could see nothing, objects on the water are now pencilled out in luminous relief.
Deep down below the water there is a listening "ear"—a submarine telephone device through which a submarine betrays its presence; any sound the undersea boat makes, the beating of the propellers, for instance, is heard by this ear, and in turn by the ear of the man who holds the receiver.
Presently the man who is on detector watch grows tense. He listens attentively and then stands immobile for a moment or so. Then he steps to a telephone and a bell rings in the chart-house where the captain and his navigating and watch officers are working out the courses and positions.
"I hear a submarine signalling, sir," comes the voice from the depths to the captain who stands by the desk with the receiver at his ear.
"What signal?" barks the skipper.
"MQ repeated several times. Sounds as if one boat was calling another." (The sailor referred to the practice which submarines have of sending subaqueous signals to one another, signals which are frequently caught by listening war-ships of the Allies.)
The captain orders the detector man to miss nothing, and then a general alarm (to quarters) is passed through the great vessel by word of mouth. This is no time for the clanging of bells and the like. The lookouts are advised as to the situation.