The Code was certainly in existence at the date referred to, but its use was neither general nor compulsory. The peculiar requirements of the service upon which ships of war are engaged, and the practice of cruising together in fleets or squadrons, necessitate the establishment of a system of signalling which shall be both rapid and effective. Such a system has been in operation in the Royal Navy for many years. Numerous modifications have been made latterly in the Admiralty signal books; those changes being rendered necessary by the altered conditions of naval warfare and the scientific precision which is desirable in the movements of a fleet of warships. An admiral in command of a fleet has now at his disposal such an effective equipment and complete organisation as would enable him to manœuvre his ships in presence of the enemy with almost mathematical exactitude. The ‘signal staff’ on board the ship which carries the flag of the commander-in-chief consists of about twenty persons, officers and men, whose duty it is to convey the admiral’s orders to the captains under his command by the varied systems of signalling prescribed for use in Her Majesty’s ships. The ‘staff’ is divided into ‘three watches;’ and by day and night, in harbour and at sea, a vigilant ‘lookout’ is kept, not only on board the flagship, but on every vessel in the fleet. Each ship on being commissioned is provided with a General Signal Book, Vocabulary Signal Book, and a semaphore. For use at night, a flashing lamp, and recently, an electrical apparatus, are supplied. By an ingenious arrangement, any of the signals contained in the books may be made during thick weather by the steam whistle or the fog-horn. Before putting to sea, a ‘fleet number’ is assigned to each ship, the admiral’s ship being No. 1, the remaining numbers being distributed according to the seniority of the respective captains. If the commander-in-chief wishes his squadron to sail in one line, he makes the signal, ‘Single column in line ahead,’ by means of three ‘numeral’ flags. This signal, like every other evolutionary signal, is kept flying at the mast-head until the signal officer reports, ‘All answered, sir.’ The fact that the admiral’s signal is seen and understood is signified, in the case of tactical orders, by each ship repeating the flags. When the proper moment arrives for executing the movement, the flagship’s signal is swiftly hauled down, the helms are put ‘hard over,’ the ships swing round in the admiral’s wake, and the evolution is complete.