Overnight a long black lighter, filled with carboys of distilled water, had been towed alongside and made fast to the submarine, and now the tarpaulin cover was hauled back and a long, flexible rubber tube passed up out of the fore-hatch and its end dropped into one of the carboys. Presently Seagrave appeared armed with a stick of nitrate of silver with which he tested in turn the contents of each of the water-holders. Two of them were found wanting, for they clouded under the operation, and were condemned as unfit for use in the sensitive internals of a battery, and when he had satisfied himself with the others he gave the order to ‘carry on.’ With much labour the T.I. and Jevons filled the tube with sterilised water and passed the free end across to the boat and down the conning-tower hatch, the S.T. firmly grasping its extremity for fear of wetting the sacred brasswork. The siphon thus formed was a labour-saver of a large order and did away with the necessity of passing the water below in buckets and perhaps rendering it dirty in the process. Down below a sound of rasping and hammering came from the engine-room where the E.R.A.s and stokers were effecting repairs, where there had been ‘a bit of a mess up aft, sir,’ and could be seen wielding spanners and lumps of waste in a masterly manner. The L.T.O. was gravely attending to the volt-metre board, whose vagaries had given trouble of late, and the second coxswain was oiling the bearings of the hydroplane and rudder shafts and generally making himself useful. The remaining seamen were cleaning brass as if their lives depended on it, a state of things that was liable to undergo a slight modification on Seagrave’s departure. ‘’Ere, Sam,’ called the T.I., ‘give us a ’and with this deck-cloth,’ as that worthy paused on his round to wipe an oily brow. Together they rolled back the canvas carpet, disclosing a solid rubber covering bolted to the deck with iron battens, which on being raised exposed a series of hatches beneath which was the for’ard battery. One of these was then lifted and the operation of ‘topping up’ began.