Rome. To protect the empire against their incursions, the Emperor Probus constructed a wall, which, however, proved but a feeble defense. [Sidenote: Provinces.] [Sidenote: Results of successive conquests.] [Sidenote: Vastness of the political power.] [Sidenote: Empire universal.] This immense empire was divided into thirty-six provinces, exclusive of Italy, each of which was governed by a proconsul. The most important of these were Spain, Gaul, Sicily, Achaia, Asia Minor, Syria, and Egypt. Gaul was more extensive than modern France. Achaia included Greece and the Ionian Islands. The empire embraced the modern states of England, France, Spain, Holland, Belgium, Switzerland, Bavaria, Austria, Styria, the Tyrol, Hungary, Egypt, Morocco, Algiers, and the empire of Turkey both in Europe and Asia. It took the Romans nearly five hundred years to subdue the various states of Italy, the complete subjugation of which took place with the fall of Tarentum, a Grecian city, which introduced Grecian arts and literature. Sicily, the granary of Rome, was the next conquest, the fruit of the first Punic War. The second Punic War added to the empire Sardinia, Corsica, and the two Spanish provinces of Baetica and Tarraconensis--about two thirds of the peninsula--fertile in the productions of the earth, and enriched by mines of silver and gold, and peopled by Iberians and Celts. The rich province of Illyricum was added to the empire about one hundred and eighty years before Christ. Before the battle of Actium, the empire extended over Achaia, Asia Minor, Macedonia, Narbonensic Gaul, Cyrenaica, Crete, Cilicia, Cyprus, Bithynia, Syria, Aquitania, Belgic and Celtic Gaul. Augustus added Egypt, Lusitania, Numidia, Galatia, the Maritime Alps, Noricum, Vindelicia, Rhaetia, Pannonia, and Mosia. Tiberius increased the empire by the addition of Cappadocia. Claudius incorporated the two Mauritanias, Lycia, Judaea, Thrace, and Britain. Nero added Pontus. These various and extensive countries had every variety of climate and productions, and boasted of celebrated cities. They composed most of the provinces known to the ancients west of the Euphrates, and together formed an empire in comparison with which the Assyrian and Egyptian monarchies, and even the Grecian conquests, were vastly inferior. The Saracenic conquests in the Middle Ages were not to be compared with these, and the great empires of Charlemagne and Napoleon could be included in less than half the limits. What a proud position it was to be a Roman emperor, whose will was the law over the whole civilized world! Well may the Roman empire be called universal, since it controlled all the nations of the earth known to the Greeks. It was the vastest centralization of power which this world has seen, or probably will ever see, extending nearly over the whole of Europe, and the finest parts of Asia and Africa. We are amazed that a single city of Italy could thus occupy with her armies and reign supremely over so many