On the other hand the aircraft carrier constitutes a new weak ness, as well as a new menace. Huge vulnerable vessels, they must suit their course to the wind when flying off their aircraft. This may lead them away from the cover of their battle fleet and expose them to the attack of enemy light forces or bombing and torpedo aeroplanes. The protection of his aircraft carriers must add appreciably to the anxieties of the commander-in-chief in battle, and the tendency of this new factor in naval war seems likely to be to complicate tactics more than ever. The destroyer, like the cruiser, is likely to hold her own as a necessary type of unit until the time arrives, if it ever does, when aircraft can function as surely as surface craft under all conditions of weather and light. Then, and only then, are we likely to see that tre mendous metamorphosis in naval tactics and in naval construction which imaginative writers on air matters are wont to Two aspects of naval tactics have given rise to considerable controversy : the amount of freedom of action to be allowed to individual squadrons and units, and the extent to which a fleet should be divided in order to round up a retreating enemy or to concentrate on his van, rear or flank. The matter is one which has decreased in importance with the reduction in number of units in the battle fleet rendered obligatory by the Washington agreement. But in case of a long war when this agreement would no longer operate and additional battleships might be built, it is conceivable that the problem might assume something of the proportions which it did at Jutland.
There can be very little question but that officers commanding squadrons of light cruisers or flotillas of destroyers should be given very considerable latitude in order that they may make the most of opportunities which present themselves. The same may be said with regard to battle cruisers which have greatly superior speed to an enemy's battle fleet. But in the case of the battle fleet itself, experience has shown that, except where a division has very marked superiority of speed, it is exceedingly dangerous for part of the battle line to break away and indulge in independent tactics, as this involves grave risk of the enemy being able to concentrate on one part or the other with his whole force. In principle the same arguments apply to individual ships, but circumstances may arise, particularly in the case of light craft at night, where the individual encounter may demand inde pendent action. Nevertheless, whatever degree of licence is given to or assumed by subordinate commanders, they must at all times be guided by the main tactical plan or strategical aim of the commander-in-chief. For instance, at Jutland (q.v.) it was Admiral Jellicoe's object to manoeuvre the Grand Fleet into a position between the enemy fleet and its line of retreat to their base. With the able co-operation of the flag officers and captains under his command this object was finely attained. But if part
of the battle fleet had launched out on an independent course of action with a view to harrying the enemy on the opposite side, under the conditions of low visibility which prevailed, it would have been out of touch with the main fleet, and this might have caused the commander-in-chief serious embarrassment. The only exception that can be made to this statement is the case of the fast division of "Barhams" (reduced to three ships soon after the main action was joined) whose speed was sufficient to enable them to draw away from the enemy's battle fleet at any time, while they were so powerful that they had nothing to fear from the faster enemy battle cruisers. It is not possible to dogmatise on the subject of naval tactics; so much must depend on circum stances, but it can be said confidently that the keynote of success in a fleet action will be in the future, as it has been throughout the ages, that co-operation between all commands which springs from complete mutual understanding and inspiring leadership. (E. A.) BIBLIOGRAPHY.—A. T. Mahan, The Influence of Sea Power upon His tory (189o), The Influence of Sea Power on the French Revolution and Empire (2 vols., 1892) ; State Papers relating to the Defeat of the Spanish Armada (ed. J. K. Laughton, 2 vols. 1894) ; J. S. Corbett, Drake and the Tudor Navy (1898) ; England in the Mediterranean (1904) ; England in the Seven Years' War (19°7) ; The Campaign of Trafalgar (Iwo) ; Some Principles of Maritime Strategy (1910 ; H. Richmond, The Navy in the War of (3 vols., 1920) ; W. S. Churchill, The World Crisis (4 vols., 1923-27) ; R. Custance, A Study of War (1924, 2nd ed. 1927) ; G. Ellison, The Perils of Amateur Strat egy (1926) ; W. N. James, The British Navy in Adversity (1926) ; Official History of the Russo-Japanese War (ed. E. 0. Swinton, 3 vols., 1910–zo) ; J. Corbett, Official History of the War. Naval Operations, 1914-16 (192o, etc.) ; A. Hurd, Italian Sea Power and the Great War (1918), Official History of the Merchant Navy (3 vols., 1920-24) ; C. E. Fayle, Official History of Sea-Borne Trade (1920) ; Earl Jellicoe, The Grand Fleet, 1914-16 (1919), The Crisis of the Naval War, 1916-17 (192o) ; R. H. S. Bacon, The Dover Patrol (2 vols., 1919) ; A. P. F. von Tirpitz, My Memoirs (1919) ; R. Scheer, Germany's High Sea Fleet in the World War (1920) ; W. S. Sims, The Victory at Sea (192o) ; Wester Wemyss, The Navy in the Dardanelles Campaign (1924). Tactics. J. Corbett, Fighting Instructions: Signals and Instructions, 1776-94 (1908) ; R. Custance, The Ship of the Line in Battle (1912) ; Battle of Jutland, Dispatches (Admiralty, 1916) ; H. Bingham, The Falklands, Jutland and the Bight (1919) ; Narrative of the Battle of Jutland (Admiralty, 1924) ; R. Bacon, The Jutland Scandal (1924) ; H. W. Wilson, Battleships in Action (1926) ; G. von Hase, Kiel and Jut land (trans. A. Chambers and F. H. Holt, znd ed. 1927) ; J. E. T. Harper, The Truth about Jutland (1927).