It was a fine conception to draw up all the fleets of the world in one grand review for the inspection and criticism of the student and scholar; and it is to be hoped that the author of "Fleets of the World" will be "encouraged," as he says in his preface, "to persevere in his undertaking," now so happily begun. As the history of fleets of war vessels, to which our author exclusively alludes, has much to say in regard to their military movements, we shall begin our examination of these works on the Socratic principle of first defining our terms. The word Tactics is derived from the Greek TAKTIKOS—capable of arranging; relating to drawing up; as to arrange or draw up the line of battle. Hence Tactics has been defined as the art of arranging troops, (or ships), for battle, or moving them while in the presence of the enemy, A simpler definition is that of Aeneas Tacticus who calls it "the science of Military Movements." The subject has generally been divided into two branches, grand tactics, or the tactics of battle; and elementary tactics, or the tactics of instruction.