Sea-power is a term used to indicate two distinct, though cognate things. The affinity of these two and the indiscriminate manner in which the term has been applied to each have tended to obscure its real significance. The obscurity has been deepened by the frequency with which the term has been confounded with the old phrase, 'Sovereignty of the sea,' and the still current expression, 'Command of the sea.' A discussion--etymological, or even archæological in character--of the term must be undertaken as an introduction to the explanation of its now generally accepted meaning. It is one of those compound words in which a Teutonic and a Latin (or Romance) element are combined, and which are easily formed and become widely current when the sea is concerned. Of such are 'sea-coast,' 'sea-forces' (the 'land- and sea-forces' used to be a common designation of what we now call the 'Army and Navy'), 'sea-service,' 'sea-serpent,' and 'sea-officer' (now superseded by 'naval officer'). The term in one form is as old as the fifteenth century. Edward III, in commemoration of the naval victory of Sluys, coined gold 'nobles' which bore on one side his effigy 'crowned, standing in a large ship, holding in one hand a sword and in the other a shield.' An anonymous poet, who wrote in the reign of Henry VI, says of this coin: For four things our noble showeth to me, King, ship, and sword, and _power_of_the_sea_. Even in its present form the term is not of very recent date. Grote [2] speaks of 'the conversion of Athens from a land-power into a sea-power.' In a lecture published in 1883, but probably delivered earlier, the late Sir J. R. Seeley says that 'commerce was swept out of the Mediterranean by the besom of the Turkish sea-power.'[3] The term also occurs in vol. xviii. of the 'Encyclopædia Britannica,' published in 1885. At p. 574 of that volume (art. Persia) we are told that Themistocles was 'the founder of the Attic sea-power.' The sense in which the term is used differs in these extracts. In the first it means what we generally call a 'naval power'--that is to say, a state having a considerable navy in contradistinction to a 'military power,' a state with a considerable army but only a relatively small navy. In the last two extracts it means all the elements of the naval strength of the state referred to; and this is the meaning that is now generally, and is likely to be exclusively, attached to the term owing to the brilliant way in which it has been elucidated by Captain A. T. Mahan of the United States Navy in a series of remarkable works.[4] The double use of the term is common in German, though in that language both parts of the compound now in use are Teutonic. One instance out of many may be cited from the historian Adolf Holm.[5] He says[6] that Athens, being in possession of a good naval port, could become '_eine_bedeutende_ _Seemacht_,' i.e. an important naval power. He also says[7] that