A boy and a man sat in a room of a stone house in the ancient City of Mexico, capital in turn of Aztec, Spaniard and Mexican. They could see through the narrow windows masses of low buildings and tile roofs, and beyond, the swelling shape of great mountains, standing clear against the blue sky. But they had looked upon them so often that the mind took no note of the luminous spectacle. The cry of a water-seller or the occasional jingle of a spur came from the street below, but these, too, were familiar sounds, and they were no longer regarded.