A cabin marked I.O. is entered--every room is a cabin in a naval base. Here the walls are decorated with innumerable charts with mysterious red lines. A curious device, with the names of all the ships belonging to the base painted on wooden slides, reaches across one side. It is the indicator which shows at a glance the ships at sea and those in harbour, the names of those under repair, the unit to which each vessel belongs and when she goes out or comes in for "stand-off." This is the Intelligence Office, and signals and wireless messages from the patrols and battle fleets are being almost continuously brought in and carried out by messengers. The Commanding Officer (C.O.) of a minesweeper is making inquiries about tides and the exact position on the chart of a newly located mine-field. Another officer is locking a black patent-leather dispatch-case--he is the King's Messenger or, more correctly, the "Admiralty Dispatch Bearer," who carries to and from London and the fleets all the secret correspondence and memoranda of the Naval War Staff and other important departments. A big safe in the corner of the cabin contains the secret codes and ciphers used when transmitting messages, and two overworked officers are busy at near-by desks translating signals to and from "plain English." The next cabin contains the admiral's secretary and his staff of writers. Here a flotilla commander is receiving his "sailing orders," without which no ship proceeds on a voyage. Adjoining this is the Pay Office, in which, with the exception of a newly joined recruit mortgaging his pay for two weeks ahead--he knows that he will be at sea for that time--there is a decided air of quietude. The rush in this abode of paymasters comes at the end of each month, when all the officers arrive in a body to demand the meagre fruits of their labours.