It is only on the _Ocean_ that _Universal Empire_ is practicable—only by means of _Navigation_ that all the world can be subdued or retained under one dominion. On land, the greatest numbers, and quantity of materiel, are unavailable, excepting around the spot where they are produced. The most powerful army is crippled by advancing a few degrees in an enemy’s territory, unless when aided by some catching enthusiasm; its resources get distant—communication is obstructed—subjection does not extend beyond the range of its guns, and it quickly melts away. The impossibility of dominion extending over a great space, when communication is only by land, has often been proved. The rule of Cyrus, or Alexander, the Cæsars, the Tartar conquerors[67], or Bonaparte, did not extend over a tithe of the earth; and we may believe, that, by some of these chiefs, dominion was {364} extended as widely as under land communication could be effected—further than under it could be supported. On the contrary, when a powerful nation has her warlike strength afloat, and possesses naval superiority, independent of being unassailable herself, every spot of the world, wherever a wave can roll, is accessible to her power and under her control. In a very short time she can throw an irresistible force, unexhausted by marches, and with every resource, upon any hostile point, the point of attack being in her own choice, and unknown to the enemy. In case of her dependent dominions being scattered over the two hemispheres, her means of communication, and consequent power of defending these and supporting authority, are more facile than what exists between the seat of government of any ordinary sized continental kingdom and its provinces. Were a popular system of colonial government adopted, many islands and inferior states would find it their interest to become incorporated as part of the Empire. NOTE B.