Springing upon the raised platform, Fordyce made his way for'ard and past the rise of the conning-tower until further progress was stopped by a huge cylindro-conical mass of metal lying athwart the deck. It was an unexploded 15-inch shell, weighing more than a ton. Missing its objective, the ponderous missile had sunk until it had alighted fairly upon R19's deck. Before the Sub could return and make his report, the roar of the aerial motors grew deafening, and out of the clouds swept a large, double-fuselaged biplane, bearing the distinctive Black Cross of Germany. CHAPTER XIX Forced to Ascend There were no signs of confusion on the deck of R19. Only the two after quick-firers were available, and these were promptly manned. Those of the crew who, in normal circumstances, were stationed below, threw themselves flat on the deck. The submarine could not dive without great risk of again courting the peril from which she had so recently emerged. It was even a hazardous business to keep under way, as the forward motion, combined by the fact that she was down by the head, made it a difficult matter to forge either ahead or astern. To all intents and purposes she was a motionless target for the huge battle-seaplane that manoeuvred overhead, seeking an opportunity to strafe her opponent by means of her powerful bombs. "Hoist the ensign! Let her have it, lads!" Both quick-firers were speedily in action. So rapidly were they fired that there was a constant clatter as the ejected metal cases were thrown from the breech. With his head thrown back, and a pair of binoculars to his eyes, Fordyce watched the effect of the bursting shells. Viewed from below, the sea-plane seemed in the very midst of a hollow globe of mushroom-like clouds of smoke from bursting projectiles. Ahead, astern, above and below, the shells burst. It seemed as if the hostile air-craft could not escape the inferno of flying fragments; yet, seemingly possessing a charmed existence, she swooped onwards to take up a favourable position for releasing her bombs. A heavy object, hurtling with ever-increasing velocity through the air, struck the surface of the water at less than half a cable's length on R19's port side. With a terrible din the bomb burst, churning up cascades of spray and hurling minute particles of metal in all directions. A second later another "egg" fell, fortunately without exploding, although several of the submarine's crew were well doused by the volume of foam that was flung all around. Back swept the biplane, manoeuvring for the position she had lost by her momentum. [Illustration: AHEAD, ASTERN, ABOVE, AND BELOW, THE SHELLS BURST] As she did so, she lurched violently and began a dizzy tail-dive. Twisting and turning in erratic spirals she dropped seawards. Loud cheers from R19's crew greeted her descent, but their jubilation was premature.