This epic was carried to the West, by the way of Phoenicia and Asia Minor, and played a great part in the mythology of the Greeks and Romans. "The twelve labors of Heracles may be traced back to the adventures of Gisdhubar [Izdubar] as recorded in the twelve books of the great epic of Chaldæa." (Sayce.) SCIENCE.--In astronomy and arithmetic the Chaldæans made substantial progress. The clear sky and unbroken horizon of the Chaldæan plains, lending an unusually brilliant aspect to the heavens, naturally led the Chaldæans to the study of the stars. They early divided the zodiac into twelve signs, and named the zodiacal constellations, a memorial of their astronomical attainments which will remain forever inscribed upon the great circle of the heavens; they foretold eclipses, constructed sun-dials of various patterns, divided the year into twelve months, and the day and night into twelve hours each, and invented or devised the week of seven days, the number of days in the week being determined by the course of the moon. "The 7th, 14th, 19th, 21st, and 28th days of the lunar month were kept like the Jewish Sabbath, and were actually so named in Assyria." In arithmetic, also, the Chaldæans made considerable advance. A tablet has been found which contains the squares and cubes of the numbers from one to sixty. CONCLUSION.-This hasty glance at the beginnings of civilization among the primitive peoples of the Euphrates valley, will serve to give us at least some little idea of how much modern culture owes to the old Chaldæans. We may say that Chaldæa was one of the main sources--Egypt was the other--of the stream of universal history. CHAPTER IV. ASSYRIA. 1. POLITICAL HISTORY. TIGLATH-PILESER I. (1130-1110 B.C.).--It is not until about two centuries after the conquest of Chaldæa by the Assyrian prince Tiglathi-Nin (see p. 43), that we find a sovereign of renown at the head of Assyrian affairs. This was Tiglath-Pileser I., who came to the throne about 1130 B.C. The royal records detail at great length his numerous war expeditions, and describe minutely the great temples which he constructed. For the two centuries following the reign of Tiglath-Pileser, Assyria is quite lost to history; then it is again raised into prominence by two or three strong kings; after which it once more almost "drops below the historical horizon." TIGLATH-PILESER II. (745-727 B.C.).--With this king, who was a usurper, begins what is known as the Second Empire. He was a man of great energy and of undoubted military talent,--for by him the Assyrian power was once more extended over the greater part of Southwestern Asia. But what renders the reign of this king a landmark in Assyrian history, is the fact that he was not a mere conqueror like his predecessors, but a political organizer of great capacity. He laid the basis of the power and glory of the great kings who followed him upon the Assyrian throne.