CHAPTER IX. SCIENTIFIC KNOWLEDGE AMONG THE ROMANS.

Astronomy was one of these. So far as mathematical genius is concerned, so far as astronomy taxed the reasoning powers, such men as Eratosthenes, Aristarchus, Hipparchus, and Ptolemy were great lights, of whom humanity may be proud; and, had they been assisted by our modern accidental inventions, they might have earned a fame scarcely eclipsed by that of Kepler and Newton. The Ionic philosophers added but little to the realm of true philosophy, but they were pioneers of thought, and giants in their native powers. The old astronomers did as little as they to place science on a true foundation, but they showed great ingenuity, and discovered some great truths which no succeeding age has repudiated. They determined the circumference of the earth by a method identical with that which would be employed by modern astronomers. They ascertained the position of the stars by right ascension and declination. They knew the obliquity of the ecliptic, and determined the place of the sun's apogee as well as its mean motion. Their calculations on the eccentricity of the moon prove that they had a rectilinear trigonometry and tables of chords. They had an approximate knowledge of parallax. [Footnote: Delambre, Hist. d'Astr. Anc., tom. 1, p. 184.] They could calculate eclipses of the moon, and use them for the correction of their lunar tables. They understood spherical trigonometry, and determined the motions of the sun and moon, involving an accurate definition of the year, and a method of predicting eclipses. They ascertained that the earth was a sphere, and reduced the phenomena of the heavenly bodies to uniform movements of circular orbits. [Footnote: Lewis, Hist. of Astron., p. 209.] We have settled, by physical geography, the exact form of the earth, but the ancients arrived at their knowledge by astronomical reasoning. "The reduction of the motions of the sun, moon, and five planets to circular orbits, as was done by Hipparchus, implies deep concentrated thought and scientific abstraction. The theory of eccentrics and epicycles accomplished the end of explaining all the known phenomena. The resolution of the apparent motions of the heavenly bodies into an assemblage of circular motions, was a great triumph of genius, [Footnote: Whewell, Hist. Induc. Science, v. i. p. 181.] and was equivalent to the most recent and improved processes by which modern astronomers deal with such motions."

But I will not here enumerate the few discoveries which were made by the Alexandrian school. I only wish to show that there are a few names among the ancients which are inscribed on the roll of great astronomers, limited as were the triumphs of the science itself. But, until the time of Aristarchus, most of the speculations were crude and useless. Nothing can be more puerile than the notions of the ancients respecting the nature and motions of the heavenly bodies.

[Astronomy born in Chaldea.]

Astronomy was probably born in Chaldea as early as the time of Abraham. The glories of the firmament were impressed upon the minds of the rude primitive races with an intensity which we do not feel with all the triumphs of modern science. The Chaldean shepherds, as they watched their flocks by night, noted the movements of the planets, and gave names to the more brilliant constellations. Before religious rituals were established, before great superstitions arose, before poetry was sung, before musical instruments were invented, before artists sculptured marble or melted bronze, before coins were stamped, before temples arose, before diseases were healed by the arts of medicine, before commerce was known, before heroes were born, those oriental shepherds counted the hours of anxiety by the position of certain constellations. Astronomy is, therefore, the oldest of the ancient sciences, although it remained imperfect for more than four thousand years. The old Assyrians, Egyptians, and Greeks made but few discoveries which are valued by modern astronomers, but they laid the foundation of the science, and ever regarded it as one of the noblest subjects which could stimulate the faculties of man. It was invested with all that was religious and poetical.

[Discoveries made by oriental nations.]