Page:Encyclopædia Britannica, Ninth Edition, v. 2.djvu/811

] heavens, along with some arts indispensable to society even in its earliest stages, were carried into Europe by tribes migrating from the banks of the Nile; and it is certain that the early philosophers of Greece travelled into Egypt for the purpose of acquiring a more perfect know ledge of astronomy than could be obtained in their own country. But the facts from which it can be inferred that the Egyptians had much to communicate, are few and ill-attested. They are also blended with so much absurdity and fable, that no accurate notions can be formed, from the accounts that have been transmitted to us, of the real advances which that people had made in astronomical science. The priests were the depositaries of the national knowledge ; and they carefully concealed it from the common people by shrouding it in allegories, traces of which, it has been remarked, may be detected in the institutions even of the present day.

The Phoenicians are also generally enumerated among the nations who cultivated astronomy at a very early period, though it does not appear, from any facts mentioned by ancient authors, that they devoted themselves specially to the observation of the heavens, or made any discoveries relative to the motions of the planets. That they excelled in the art of navigation is certain, from the commercial intercourse which they carried on with many places on the coasts of Africa and Spain, and with the principal islands of the Mediterranean ; and it may readily be allowed that in their long voyages they would direct their course during the night by the circumpolar stars. If they had any speculative notions of astronomy, these were probably derived from the Chaldeans or Egyptians.

In China, astronomy has been cultivated from the remotest ages, and has always been considered a science indispensably necessary to the civil government of the state. The Chinese boast of a scries of eclipses, recorded in the annals of the nation, extending over a period of 3838 years, all of which, they affirm, were not only carefully observed, but were calculated and figured previous to their occurrence. The same motives which led the Chaldeans and Egyptians to attend to the celestial phenomena, namely, the regula tion and division of time, had equal influence among the Chinese, and we accordingly find the care of the calendar occupying the attention of their earliest princes. The emperor Fou-Hi, whose reign commenced about 2857 years before our era, is said to have assiduously studied the motions of the celestial bodies, and laboured to instruct his ignorant subjects in the mysteries of astronomy. But as they were not yet enlightened enough to comprehend his theories, he was obliged to content himself with giving them a rule for the computation of time by means of the numbers 10 and 12, the combination of which produces the cycle of GO years, which is the standard or unit from which they deduce their hours, days, and months. Tradi tion is silent with respect to the sources from which Fou- Hi derived his t own knowledge. In the year 2G08 B.C., Hoang-Ti caused an observatory to be built, for the pur pose of correcting the calendar, which had already fallen into great confusion, and appointed one set of astronomers to observe the course of the sun, another that of the moon, and a third that of the stars. It was then discovered that the twelve lunar months do not exactly correspond with a solar year ; and that, in order to restore the coincidence, it was necessary to intercalate seven lunations in the space of nineteen years. If this fact rested on undoubted evi dence, it would follow that the Chinese had anticipated the Greeks by 2000 years in the discovery of the Metonic cycle. The reign of Hoang-Ti is also rendered memorable by the institution of the Mathematical Tribunal, for pro moting the science of astronomy, and regularly predicting eclipses, to which an extraordinary importance has always been attached in China. The members of this celebrated tribunal were made responsible with their lives for the accuracy of their predictions, by a law of the empire, which ordained that, &quot; whether the instant of the occurrence of any celestial phenomenon was erroneously assigned, or the phenomenon itself not foreseen and predicted, either negli gence should be punished with death.&quot; In the reign of Tchong-Kang, the two mathematicians of the empire, Ho and Hi, were the victims of this sanguinary law an eclipse having taken place which their skill had not enabled them to foresee. The emperor Yao, who mounted the throne, according to the Chinese annals, about the year 2317 B.C., gave a new impulse to the study of astronomy, which had begun already to decline. He ordered his astronomers to observe with the utmost care the motions of the sun and moon, of the planets and the stars, and to determine the exact length of each of the four seasons. To this emperor are attributed the Chinese division of the zodiac into 28 constellations, called the houses of the moon, and the severe laws already noticed in regard to the erroneous prediction of the celestial phenomena. From the time of Yao the Chinese year consisted of 365 days. They also divided the circle into 365^ degrees, so that the sun daily described in his orbit an arc of one Chinese degree. Their common lunar year consisted of 3G4jf days ; and by combining this number with 365^, they formed the period of 4G17 years, after which the sun and moon again occupy the same relative positions. The earliest Chinese observations we are acquainted with, sufficiently precise to afford any result useful to astronomy, were made by Tcheou-Kong, whose reign commenced about the year 1100 before our era. Two of these observations are meridional altitudes of the sun, observed with great care at the village of Loyang, at the time of the summer and winter solstices. The obliquity of the ecliptic thus determined at that remote epoch is 23 54 3&quot; - 15 a result which perfectly agrees with the theory of universal gravita tion. Another observation made about the same time relates to the position of the winter solstice in the heavens ; and it also corresponds to within a minute of a degree with the calculations of Laplace. Laplace considers this extra ordinary conformity as an indubitable proof of the authen ticity of those ancient observations. The golden age of Chinese astronomy extended from the reign of Fou-Hi to the year 4SO B.C., that is, over a space of 2500 years. It is only, however, towards the latter part of this long period that the history of China becomes in any degree authentic ; and the true date which must be assigned for the commencement of observations on which any reliance can be placed, is the year 722 B.C., that is, 25 years posterior to the era of N&quot;abonassar. From that period to the year 400 B.C., Con fucius reckons a series of 3G eclipses, and of these 31 have been verified by modern astronomers. After this the science fell into great neglect, notwithstanding the invete rate tenacity with which the Chinese in general adhere to their ancient customs. The decline of their astronomy is ascribed, whether justly or not, to the barbarous policy of the emperor Tsin-Chi-Hong-Ti, who, in the year 221 B.C., ordered all the books to be destroyed, excepting those only which related to agriculture, medicine, and astrology, the only sciences which he considered as being of any use to mankind. In this manner, it is said, the precious mass of astronomical observations and precepts which had been accumulating for ages was irretrievably lost. On considering attentively the accounts which have been given of the Chinese astronomy, we find that it consisted only in the practice of observations which led to nothing more than the knowledge of a few isolated facts. The missionaries who were sent out by the Jesuits about the end of the 17th century, to whom we are indebted for 