Tactics, the movements and disposition of troops adopted by contending forces when they are face-to-face and desire to gain some immediate advantage. The sphere of tactics must not be confused with that strategy, which is concerned with the general conduct of the campaign rather than with its details at any one time or spot. The distinction is made between various kinds of tactics, according to the character and extent of the operations, the troops employed, and other circumstances. Thus grand tactics and manoeuvre tactics deal with those comprehensive movements on which hangs the fate of great battles, whilst minor tactics relate to outposts, reconnaissance, the action of advanced and rear guards, and other operations on a small scale. So again there are tactics of cavalry, infantry, and artillery, combined tactics, siege tactics, and mining tactics. In naval, as in military, warfare there is a broad distinction between tactics and strategy. Naval tactics are concerned with the management of ships and fleets during an action, whereas the aim of naval strategy is to obtain and keep the command of the sea. The Battle of Salamis (q.v.) is an ancient example of the skillful employment of tactics according to recognized rules. At an early date it had become an accepted principle that force should be concentrated against some point of the enemy's fleet, which would then serve as a "basis of operations." The advantage of obtaining the weather-gage, so as to facilitate the boarding of the enemy's ships, was also fully appreciated. But the modern "line-of-battle" dates only from the war between England and Holland during the Commonwealth and the reign of Charles II., when it was introduced into both navies. It is said that the original purpose of the line-of-battle composed of ships drawn up either abreast or one behind another, so as to afford mutual assistance at the shortest notice, was to avert the havoc wrought by fire-ships. The manoeuvre of breaking the enemy's line by cutting through it was carried out with the utmost skill by Rodney in 1782. In several of Nelson's great battles, notably in that of Trafalgar, he showed himself an unrivaled master of tactical resource. Since his days the circumstances attending naval actions have been much changed through the introduction of steam and armour-plating, and it is impossible to say what manoeuvres would now be employed in a battle between ironclads.