was unexplored, and for the most part went naked, and the Americas were not yet populous. Therefore, while Britain might have annexed almost every coast outside Europe except the Atlantic coast of the United States, she limited herself to calling ports for her shipping on the ocean road to the Indies, and to such colonial developments in unoccupied regions as were forced on her by her own adventurers, whom she tried in vain to check. But she was compelled to make a steady advance in India, of that kind which old Rome had known so well, when one new province after another was annexed for the purpose of depriving invaders of their bases against the territory already possessed.
The map reveals at once the essential strategic aspects of the rivalry between Russia and Britain during the nineteenth century. Russia, in command of nearly the whole of the Heartland, was knocking at the landward gates of the Indies. Britain, on the other hand, was knocking at the sea gates of China, and advancing inland from the sea gates of India to meet the menace from the north-west. Russian rule in the Heartland was based on her man-power in East Europe, and was carried to the gates of the Indies by the mobility of the Cossack cavalry. British
