The owners of the _Leviathan_ are also the proprietors of the ship shown in our next illustration. This, the _Vigilant_, is seen alongside the crane in the Herculaneum Dock, Liverpool. The Dock and Harbour Boards are practically local Trinity House brethren, though totally independent bodies. Just as the Trinity House authorities have the upkeep of the light-houses and lightships round the English coast, so the Dock and Harbour Boards are charged with the duties of keeping the local buoyage in efficient order for ensuring safe navigation into and out of their ports and estuaries. Gas buoys have to be refilled periodically, moorings have to be laid down afresh, and, in the case of damage, replaced. Periodically these have, in any case, to be brought ashore to be overhauled, repainted and then returned to their duties, bobbing about to the ceaseless heave of the waves. For such work as this the _Vigilant_ is employed. The illustration shows a gas buoy being lowered on to her deck from the quay. Not very long ago an out-going steamship from Liverpool fouled one of the Mersey buoys in a curious manner. She was proceeding in such close proximity to the latter that she actually caught her propeller in one of the mooring chains, with, as may be expected, consequent damage. [Illustration: THE SUCTION DREDGER “LEVIATHAN.” _From a Photograph. By permission of the Mersey Docks and Harbour Board._] [Illustration: THE “VIGILANT.” _From a Photograph. By permission of the Mersey Docks and Harbour Board._]