Down in the bow compartment the alert L.T.O.'s depressed the firing-levers of the two 21-inch tubes. A faint hiss as the compressed-air propulsive charges expelled the steel cylinders, and the gurgling sound of inrushing water, to compensate the weight of the missiles, alone announced to the cool and determined men that their part of the immediate business was completed. Whether it was to be "hit or miss" they were not to know at present. It depended upon the skill of their daring skipper. Stockdale took his chance with fate. The moment he made certain, by the air-bubbles in the wake of the locomotive weapons, that the torpedoes were speeding towards their mark he dived. So far so good; but sheer curiosity prompted him to bring the submarine towards the surface until her periscopes were exposed. True, he ran several hundred yards under water before he did so. In the midst of a terrific cannonade the roar of the double explosion was indistinguishable to the crew of R19. All they could hear was a constant rumble. They were attacking under novel conditions as far as they were concerned. It was not a case of lying in wait for a passing hostile craft. Shells were flying in all directions, torpedo-boats, on the look-out for submarines, were in attendance upon the larger vessels. Whether some of the shells were being fired with the intention of "doing in" the daring British craft none of her crew would know until the submarine received a hit. As the light grew brighter on the object-bowl of the conning-tower periscope, both officers gave vent to a satisfied grunt. Eight hundred yards away the German battleship was settling by the stern with a terrific list to starboard. Smoke and steam were pouring from her three funnels, her decks were thick with humanity, while already many of the crew were scrambling down the sloping sides of the listing hull. Destroyers were making for the sinking ship to pick up the survivors, while others were maintaining a hot fire upon a totally imaginary periscope a full half mile from those of R19. Realizing that it was decidedly "unhealthy" to prolong the satisfactory observation, the Hon. Derek gave orders to dive to 90 feet. In the turmoil of agitated water the submarine would be safe from the inquisitive attentions of Zeppelins and other German air-craft. Before the raised periscopes could dip beneath the waves a dull crash sounded almost immediately above the head of the Lieutenant-Commander and the Duty Sub in the conning-tower. Simultaneously the vision in the object-bowl vanished and the electric lamps were shattered into framents. "They've bagged us this time," thought Fordyce, but, restraining an inclination to shout a cry of alarm, he compressed his lips firmly and awaited the end. In the pitch-dark blackness, momentarily expecting to be overwhelmed by the inrush of water, he stood rigidly prepared to face the Unknown like a true British seaman.