These early astronomical studies resulted in the division of time practically as we know it to-day. The Babylonians had a week of seven days. The days bore names of the planets and were divided into hours and minutes. Days were combined into months and years. The Babylonian and Chaldean astronomers, like those of China and India, were important men and were credited with great learning. The Babylonian month began on the evening when a new moon was first observed. An adjustment was made necessary between the months, owing to the fact that the actual lunar interval is about twenty-nine and a fraction days. Numerous astrological observations were made with the view of obtaining data to facilitate the monthly adjustments. The taking of these observations was made easier by maps of the heavens which were recorded on baked clay tablets and prisms. Similar maps of the world, with positions fixed by astronomical observations, were likewise made in Babylonian times. The usefulness of astronomical observations and predictions led to the belief that they could be employed with advantage for wider purposes. The astrologers endeavored to deduce omens and forecast horoscopes. In order to facilitate their calculations, the astrologers invented calculating and time-dividing machines. Tablets from the royal library at Nineveh indicate that Chaldean astrologers possessed mechanisms which divided the hours of the day by mechanical means. These were forerunners of modern clocks and timepieces. These early scientists represented the earth as a vast circular plain, intersected by high mountain ranges and surrounded by a large river, with other mountain chains which lost themselves in an infinite ocean. The heavenly vault was believed to be supported by the highest peaks of the outlying mountains. It was owing to the peculiar nature of this cosmogony that the pre-Babylonians and Babylonians were unable to develop a satisfactory mechanical view of the world. The world had to wait for an adequate mechanical theory before general knowledge could be advanced, so that men like Newton and Laplace could correct the errors of early theories and furnish a sound working hypothesis.