=19. Athenian imports and policy.=—The chief import was wheat, on which Athens was then as dependent as England is now; the city had grown so great by trade that the surrounding country was unable to support it. The great granary of Athens was the level country north of the Black Sea, and the Athenians made extraordinary efforts to control the narrow entrance to the Black Sea, that they might assure their food supply. They were not entirely dependent on this source, however, and imported wheat also from Sicily, Egypt, Syria, and the mainland to the North. Among the other imports were ship-building materials, salt fish, slaves, raw materials for the Athenian manufacturers, and articles of luxury. The breadth of the Athenian trade is pictured in the statement of a contemporary: “What delicacies there are in Sicily, or Lower Italy, or Cyprus, or Egypt, or Lydia, or on the Pontus, or in Peloponnesus, or anywhere else, they all are brought to Athens by her control of the sea.” The commercial policy of the Athenians was framed with an eye especially to the interests of the consumer. What duties were levied were low, and had no leaning to “protection” in the modern sense. The export of articles especially desired (wheat, ship-building materials) was restricted in the hope of keeping up the home supply, and commercial advantages were granted or withheld with the idea of exercising political pressure on other states; but nothing like modern protectionism can be found in the commercial policy of this period. =20. Contrast of the ancient and modern world; effect of Macedonian and Roman conquests.=—In the course of our narrative we are now approaching a point when a great change came over the ancient world. The isolation of the earlier states of antiquity is their most striking feature. Each one lives only unto itself. It rises in civilization and then declines, without sharing its gains and losses with other states. It may conquer and hold them for a time, it is true, but it rules them as foreign territory, with alien interests; and the great empires crumble as readily as they are made. This characteristic of ancient history is one of its main difficulties to the student, for it deprives him of any bond of connection between the peoples, and forces him to pass from one to another of them, until he feels lost in the complexity of the narrative.