Meanwhile Boyd at the periscope was keeping a careful look out for approaching craft. A collier in her way in came perilously close, but the watchful trawler headed her off and led her out of harm’s way. As the tanks flooded his sky view became less and less; as the instrument was fully hoisted he could guess she was settling down before the gauge began to register. Finally, Raymond came down from the control room to see that all was as it should be. ‘She’ll do now,’ he explained to the passengers. ‘She’s got all the ballast she wants, and only needs a touch to take her down. We’re like a bottle half-full of water--just on the bob, as it were.’ Another look round and then: ‘Start the motors,’ he added ‘Full fields. Take her down gently.’ The boat gave a slight shudder, and the sound of the water could be heard lapping past her as she gathered weigh. The coxswains spun their wheels, eyes on the gauge, and gradually she crept down to thirty feet. ‘Hold her at that,’ said Raymond, and then he and Seagrave and the dockyard experts made a tour of the boat, while Boyd lowered the periscope and kept an eye on the helmsman to see that he was on his course. The inspection proved satisfactory (it was a lengthy business), and the party returned to the control room, and Raymond ordered the motors to be stopped and the boat was brought up to 18 feet. ‘All clear, Boyd?’ he asked. ‘All clear, sir. The trawler’s just astern.’ ‘Right. Group up. Thirty feet.’ ‘Grouped up, sir,’ from Furness, as the grouper-switch came over with a bang and the motors got away in earnest. The boat was doing a good eight knots now, and could be felt vibrating through the water as the speed increased. All eyes were on the gauges, the coxswains watching their depths and the L.T.O.s their ammeters as Raymond increased to 800 amperes. Then once more the motors were stopped and the batteries placed in parallel or ‘grouped down,’ and then came the order,-- ‘Eighty feet.’ As the hydroplane and diving rudder wheels went over, the visitors’ expressions became a little tense and anxious. One of them laughed and cracked a stale joke, another fidgeted with a bunch of keys, but nobody said anything. That sense of proportion was developing. The depth needle crept up to the requisite depth and steadied, and then another tour of inspection took place, for leaks this time, and was also pronounced satisfactory. The visitors breathed again, but thoughts of the fresh air and sunlight up above _would_ obtrude themselves nevertheless. It seemed so still and quiet, and the electric light glared and winked on the brass work while up above.... ‘A hundred feet.’