Page:Encyclopædia Britannica, Ninth Edition, v. 2.djvu/812

746 what is known of the early history of China, either seduced by some appearances of truth, or thinking it prudent to conciliate the people whom they were attempting to convert, adopted their marvellous relations regarding the antiquity of their science, and spread them over Europe. As the history of the nation begins to become more authentic, their astronomy shrinks into its real, insignificant dimen sions. Superstitiously attached to their ancient usages, and blindly adopting the habits of their ancestors, the Chinese continued to observe the heavens from century to century without making the slightest advances in theo retical knowledge. In later times they have adopted many improvements, for which they are entirely indebted to foreigners. During the time of the caliphs many Maho metans passed into China, carrying with them the astro nomical methods and knowledge of the Arabians. The missionaries introduced the science of Europe ; and the most that can be said in praise of the Chinese is, that their Government sometimes relaxed so far its spirit of jealousy and exclusion, as to afford protection to these strangers, adopt their arts, and place them at the head of the Mathematical Tribunal.

The astronomy of the Indians forms one of the most curious problems which the history of science presents, and one which, notwithstanding much discussion, still continues involved in great uncertainty. Of the science of the ancient nations of which we have already spoken, the accounts which have come down to our times are founded on conjecture and tradition ; for few monuments remain to confirm or confute the glowing descriptions which authors have given of its high antiquity and great perfec tion. But the claims of the Indians rest on a more solid foundation. We are in possession of the tables from which they compute the eclipses and places of the planets, and of the methods by which they effect the computation ; we have, in short, an Indian astronomy committed to writing, which represents the celestial phenomena with considerable exactness, and which, therefore, could only be produced by a people far advanced in science. But the difficulty the problem presents is the determination of the sources whence this science originated and the epoch of its existence the question whether it was created by the people who now blindly follow its precepts without under standing its principles, or was communicated to them by an other race of a more original genius through channels with which we are unacquainted. Some authors regard India as the cradle of ail the sciences, particularly of astronomy, which they suppose to have been cultivated there from the remotest ages ; others date the origin of the Indian astro nomy from the period when Pythagoras travelled into that country, and carried thither the arts and sciences of the Greeks ; a third opinion is, that astronomy was conveyed to India by the Arabians in the 9th century of our era, and that the Brahmins are only entitled to the humble merit of adapting the rules and practices of that people to their own peculiar methods of calculation.

Astronomy of the Greeks.

The origin of astronomy in Greece, as in other early nations, ascends beyond the period of authentic history. The true foundations of Grecian science were laid by, who was born at Miletus 640 years before our era. He formed a sect which has been distinguished by the title of the &quot; Ionian School.&quot; His doctrines regarding astronomy contain a few truths which do honour to his sagacity and observation, though they are mixed with much error and absurdity. He taught that the stars are formed of fire ; that the moon receives her light from the sun, and is invisible at her conjunctions, because she is hid in the sun s rays. He also taught the sphericity of the earth, which he placed at the centre of the universe. He divided the sphere into five zones, by the arctic and antarctic circles, and the two tropics ; and held that the equator is cut obliquely by the ecliptic, and perpendicularly by the meridian. He is also said to have observed eclipses ; and Herodotus relates that he predicted the famous one which put a stop to the war between the Medes and the Lydians. It does not appear, however, that he ventured to assign either the day or the month of the eclipse, so that his prediction must have been confined to the year. According to Callimachus, he determined the positions of the stars which form the Lesser Bear, by which the Phoenicians guided themselves in their voyages. It is difficult, however, to conceive how Thales, unacquainted with instruments, could determine the positions of stars with so much accu racy as to render any essential assistance to the navigator. It is probable that he only pointed out the configuration and some of the more brilliant stars of that constellation, among which he might remark that which is nearest the pole of the heavens. Thales was succeeded by, to whom also is attributed a knowledge of the sphere and of the zodiac. According to Diogenes Laertius, he, like his master Thales, supposed the earth to be spherical, and placed at the centre of the universe ; but Plutarch ascribes to him the less philosophical opinion of its resemblance to a column. He supposed the sun to be of equal magnitude with the earth. He invented the gnomon, and placed one at Lacedaamon to observe the solstices and equinoxes. The circumstance which best entitles Anaximander to the gratitude of posterity is the invention of geographical charts. succeeded Anaximander in the Ionian school, and maintained nearly the same doctrines. Pliny says he was the first who taught the art of constructing dials, an invention which, as we have just seen, has also been ascribed to Anaximander. These two philosophers probably revived the knowledge of an in strument, the use of which had been forgotten amidst the general rudeness and ignorance of their countrymen. Before their time the Greeks only marked the divisions of the day by the different lengths of the sun s shadow. was the disciple and successor of Anaximenes. If this philosopher really entertained the ridiculous opinions ascribed to him by Plutarch, the Ionian school must rather have retrograded than advanced in sound philosophy from the time of Thales. He is said to have believed that the sun is a mass of red-hot iron, or of heated stone, somewhat bigger than the Peloponnesus, that the heaven is a vault of stones, which is prevented from tumbling only by the rapidity of its circular motion, and that the sun is prevented from advancing beyond the tropics by a thick and dense atmosphere, which forces him to retrace his course. These alleged opinions are probably greatly exaggerated ; but it does not appear that Anaxagoras contributed much to extend the knowledge of the heavens. His disregard for the superstitious notions of his age brought its usual penal consequences. Having shown the reason of the eclipses of the moon, he was accused of ascribing to natural causes the attributes and power of the gods ; and having taught the existence of only one God, he was accused of impiety and treason towards his country. Sentence of death was pro nounced on the philosopher and all his family; and it required the powerful interest of his friend and disciple Pericles to obtain a commutation of the sentence into one of perpetual banishment.

While the Ionian sect was so successfully employed in cultivating and propagating a knowledge of nature in Greece, another, still more celebrated, was founded in Italy by. Pythagoras is said to have acquired in Egypt the knowledge of the obliquity of the ecliptic, and of the identity of the morning and evening stars. 