At the same time, we must bear in mind that the influence exercised upon the history of mankind by the general configuration of land and sea, or any special features of the former, is subject to change, and depends essentially upon the stage of culture at which nations have arrived. Geography, strictly speaking, confines itself to a description of the earth’s surface, and exhibits the various nations in a passive attitude as it were, whilst Historical Geography and statistics show man engaged in the struggle for existence, and striving to obtain the mastery over his surroundings. A river, which to an uncultured tribe would constitute an insurmountable barrier, becomes a commercial high-road to a tribe further advanced in culture, and in process of time it may be converted into a mere canal of irrigation, the course of which is regulated by man. A mountain range frequented by shepherds and huntsmen, and forming a barrier between nations, may attract, in a more civilised epoch, the miner and the manufacturer, and in course of time will even cease to be an obstacle, as roads will traverse it in all directions. Many a creek of the sea, which afforded shelter of yore to the small vessels of our ancestors, is deserted now, whilst the open bays, which vessels dreaded formerly, have been protected by enormous breakwaters, and have become the resort of our largest ships. {5} Innumerable changes such as these have been effected by man in all parts of the world, and they have revolutionised the correlations existing between man and the land he lives in. The configuration and height of mountains and table-lands, the indentation of the coasts, the disposition of islands and archipelagos, and the extent of the ocean—these all lose their relative influence upon the history of nations in proportion as the latter emancipate themselves and become free agents. Though subject to the condition of his dwelling-place, man may modify it to suit his own purpose; he may overcome nature as it were, and convert the energies of the earth into domesticated forces. As an instance we may point to the elevated table-lands of Central Asia, which now separate the countries and peninsulas surrounding them, but which, when they shall have become the seats of human industry, will convert Asia into a real geographical unit, which at present it is only in appearance. Massy and ponderous Africa, monotonous Australia, and Southern America with its forests and waterfalls, will be put on something like an equality with Europe, whenever roads of commerce shall cross them in all directions, bridging their rivers, and traversing their deserts and mountain ranges. The advantages, on the other hand, which Europe derives from its backbone of mountains, its radiating rivers, the contours of its coasts, and its generally well-balanced outline are not as great now as they were when man was dependent exclusively upon the resources furnished by nature.