And now that we are inside, it looks an even more dangerous place for an intruder--a perfect hornets’ nest. Close to us on the left lies a small pier, with buildings on a hill behind it--the Commodore’s house and offices, seamen’s training-school, and gymnasium. At the pier-head are two or three picket-boats; and a little further on, a light cruiser with her observation balloon mounted. The vast sheds beyond are the hangars of the Air Service. They are painted in a kind of Futurist style, which gives them a queer look from below, but makes them, when seen from a thousand feet up, either invisible or like a landscape of high roads, cornfields, hay-stacks and groups of trees--objects quite uninviting to any stray air-raider. But their best protection is the efficiency of the machines and men inside them. Over on the opposite side of the river stretches a long quay. The background of it is a naval railway station; the ships lying in front of it are partly supply ships, partly merchant vessels brought in under convoy, and two of them are depot ships, moored permanently there, and used as headquarters for the Submarine, Destroyer, and other services. Out in the centre of the harbour lies a still larger depot ship, the floating headquarters of the Admiral who is Commodore of the port; and behind her, in two long lines, stretching away upstream into the far distance, lies an apparently inexhaustible force of light cruisers, destroyers, and destroyer-leaders, with here and there a submarine--one is slung aloft in a dry-dock for overhauling. A side creek to the left is crowded with trawlers and drifters, whose men are now ashore ‘between sweeps.’ At this hour of the day the place is at its fullest, for the daily ‘Beef Trip,’ or food convoy, has just come in, and the dozen destroyers which escorted it are all lying at their moorings, on both sides of the main stream line. There they will be till to-night, when at 7 o’clock to the second they will all slip away again into the twilight like thin grey ghostly dogs, shepherding another flock of very substantial sheep.