‘We blew what we could, but she hadn’t got a central control like we have in the later boats, and of course nothing happened. The depth-gauge stuck at 48 feet, and the air was getting bad already. There were fourteen of us in the control room--a space about seven feet by nine. ‘I was standing by one of the bulkhead doors, and was the first to suspect it. I didn’t say anything till I was sure, and smelt and smelt again till there was no doubt about it. The water had got to the batteries, and chlorine gas was creeping through the doors. ‘There was only one way out of it, and that was the old conning-tower dodge. We reckoned we had about half an hour to live, as the gas was only coming in slowly, and we might be able to save the lot if the air didn’t give out first. ‘You know the shaft of the conning-tower that leads down into the control room has two hatches, one at the top, opening out on deck, and the other at the bottom where the shaft breaks out into the skin of the hull. The space between was just big enough for a man to stand, and forms an air-lock. ‘I wanted Belton to go up first, but of course he wouldn’t have it. He insisted that an officer must go first to test the working of it, and if all went well to explain technically when he reached the top what was the matter with us. As he was the captain I had to go.’ Allison broke off and shuddered at the remembrance, and it was some time before he continued. ‘I pushed up the lower lid and climbed into the conning-tower, and as I held the flap I looked down on the little crowd of upturned faces. “Good luck, George,” said Belton, he always called me George, “and good-bye.” ‘Then I closed the lid and stood there in the narrow space with only the upper hatch between me and 40 feet of water. I don’t quite know how I felt, but I felt afraid, and I waited a minute before I opened the sea-inlet, and the water poured into the shaft. It was all dark, of course, and I had the feeling that now at least I had burnt my boats. The arrangement was that after I had gone up, and the upper lid had been closed again from the control room, they were to pump the shaft out and the next man up would open the lower lid and take my place, and they were to give me four minutes to do it. ‘The water rose up to my thighs, and in that narrow space I could feel the air compressing terribly on my ears and mouth, and I climbed up till my head was touching the upper lid. Up came the water again, up to my chest, and I waited with one hand on the releasing gear of the lid. ‘When it reached my chin I couldn’t stand it any longer and let the hatch fly. I don’t know what happened then, but the bubble of compressed air must have shot me clean up. I remember the feeling of pressure and dark water and bursting lungs, and then I was up in the glorious sunlight that I hadn’t expected to see again.