The Chief E.R.A., who was hovering in the offing, chose his opportunity and plunged in. ‘Are you going to charge now, sir?’ he asked Seagrave. ‘We’re all ready in the engine-room.’ ‘Yes, yes,’ replied the ‘Sub.’ ‘We’ll have to do a gas-engine charge, though. “147” has got the berth at the charging pier. We’ll start with 500 in the series until the densities rise to twelve twenty-five and then give her two-fifty in parallel. Starboard Engine!’ ‘Ay, ay, sir,’ and Hoskins disappeared into his engine-room. The L.T.O. made the grouper switch and then started the starboard motor, and with the engine-clutch in the Diesel was heaved over until she fired and the engine got away by herself. The process was much the same as cranking up a motor-car, and as the revolutions increased the needle on the ammeter, which had shown discharging at first, worked slowly back, past zero and on to charging, and, after a deal of flickering, finally steadied at five hundred amperes. The L.T.O. was to look after the charge under Seagrave’s orders, and the T.I. and his minion decamped to attend to the internals of a torpedo that some one had been rude to. Every hour Furness made the sounds of the pilot-cells with a squeeze bulb--an instrument rather like a fountain-pen filler--with which he sucked up a small portion of the electrolyte and was able to read the densities. Slowly they rose until by noon, with the temperatures at about 50 deg. fahrenheit, the batteries stood at twelve twenty-five and the charge was broken. The sound of the engines died away and the L.T.O. stopped the motor. Then over came the grouper-switch to put the batteries in parallel, the motor was re-started, and in less than a minute the charge was under weigh again. The whole operation was identical with that of starting the engines at sea, the only difference being that the tail clutches were out, so that the propeller was disconnected from the shaft; also when the engines are propelling the ship the motor-switches are broken when once the Diesel is under weigh. About three in the afternoon, when the entries on the charging sheet began to look formidable, and the charge was nearing completion, Raymond came down to have a look-see, and satisfy himself that all was in order. He and Seagrave conferred for a few minutes on the ‘care and maintenance’ of secondary batteries, and then the skipper turned to the voltmeter. ‘Voltage 2.5. Yes, that’s all right. Densities 1248 and 1250. Temperatures 80 deg. and 82 deg. Um, yes. I think we’ll break the charge.’ ‘Break the charge, Hoskins,’ said Seagrave, waving towards the engine-room. ‘Ay, ay, sir,’ came the answer.