either on islands, as the Dutch East Indies, or on territories such as Portuguese Mozambique and German East Africa, which, although continental, were inaccessible under existing conditions by land-way from Europe. Save in the Persian Gulf, there could be no rival base for sea-power which combined security with the needful resources, and Britain made it a declared principle of her policy that no sea-base should be established on either the Persian or Turkish shores of the Persian Gulf. Superficially there is a striking similarity between the closed Mediterranean of the Romans, with the legions along the Rhine frontier, and the closed Indian Ocean, with the British Army on the North-West Frontier of India. The difference lay in the fact that, whereas the closing of the Mediterranean depended on the Legions, the closing of the Indian Seas was maintained by the long arm of sea-power itself from the Home base.
In the foregoing rapid survey of the vicissitudes of sea-power, we have not stayed to consider that well-worn theme of the single mastery of the seas. Every one now realises that owing to the continuity of the ocean and the mobility of ships, a decisive battle
