flying. It was a lot safer to fall up than to fall down. He changed his mind a little about the softness of it when he was dragged through a great colony of jellyfish whose stinging tentacles left his skin on fire. But he would not signal to stop - this was too much fun. Besides, he longed to be the one to locate the wreck of the Santa Cruz. In a way it seemed fantastic to expect to find a wreck on his first dive. But why not? If the glider could cover in half an hour as much ground as could be surveyed in a year with old-fashioned diving methods, his chances were good. The bottom slid swiftly by beneath him - not too swiftly, for the motor had been throttled down to six knots. He could see every detail of the ocean floor. It was covered by a thousand forms of life in all the colours of the rainbow. There were things like cabbages and roses, cauliflowers and lilies. There were fans and ferns and feathers. There were clouds of angelfish, peacock fish, and Moorish idols. He didn’t like the look of the sea snakes in spite of their gorgeous livery of blue, gold and green on. velvet brown. They glided in and out of holes in the coral or coiled around the branches. Then there would suddenly be a stretch of snow-white sand, as bare as the desert. Then would come rock land, a wild tumble of crags and boulders. He climbed sloping hills and went deep into the valleys to be sure to miss nothing at the bottom of the ravines. He noticed especially the great number of giant clams, monsters four or five feet wide with their shells agape, waiting for food. If anything should come between them the shells would close like a steel trap. Many a diver whose foot had been caught in those merciless jaws had stayed to spend eternity at the bottom of the sea. He shivered at the idea - but would have shivered more had he known the fate that one of these giants held in store for a member of the company of the Lively Lady. At the end of about ten minutes Roger felt the sled swing around and then proceed in the opposite direction. Dr Blake had covered a mile and was now doubling back. He would keep doubling until Roger had surveyed a square mile of the sea bottom. The floor here was flat and bare and looked like snow. Roger brought the sled down until the runners slid along the ground. Now he was actually sleighing at the bottom of the sea. He went up over a slight rise, then tobogganed down a long slope. The slope ended in a precipice that dropped away to great depths. Here was where a sleigh ride would end in disaster in the world above. Roger had a moment of panic as he shot out into space above the terrible abyss - but the sled soared like a bird over the yawning gulch ‘and touched ground again on the other side. Roger’s fear turned to exultation and he would have shouted with glee if he could have done so without losing his mouthpiece. He was so happy that he failed to notice a hump in the sand until it was too late. The sled ploughed into it and uprooted a large and very much surprised octopus. Having the ability to take on the colour of its surroundings, the beast was nearly as white as the sand. If it had been among brown rocks it would have been brown, or among green plants it would have turned green. But no matter what its surroundings may be an octopus always turns red when it is angry, and this one was a terrible red as it found itself caught on the prow of the glider and carried away at a speed of six knots. Some of the tentacles were below the deck and some above, and two of them fastened themselves to Roger’s bare back. The parrot-like beak of the creature was within a few inches of his face and the big, almost human eyes glared hatefully into his. His first impulse was to signal for a stop. But if he stopped, the octopus could disentangle itself from the sled and attack. So long as he kept moving it might be too bewildered or terrified to do anything but hang on. The sac-like body of the beast was beneath the edge of