Note 49 — INTRODUCTION.

We are informed by some ancient writers, that when Babylon was taken, Calisthenes, one of Aristotle’s scholars, carried from thence, by the desire of his master, celestial observations made by the Chaldeans, nearly two thousand years old; which carried them back to about the time of the dispersion of mankind by the confusion of tongues: and those observations are supposed to have been made in the famous temple of Belus, at Babylon. But these accounts are not to be depended on: because Hipparchus and Ptolemy could find no traces of any observations made at Babylon before the time of Nabonassar, who began his reign 747 years before the birth of Christ; and various writers, among the ancients, agree in referring the earliest Babylonian observations to about the same period. In all probability, the Chaldean observations were then little more than matters of curiosity; for, even in the three or four centuries immediately preceding the Christian era, the celestial observations which were made by the Greeks were, for the most part, far from being of any importance, in relation to astronomical science.

Indeed, the knowledge of astronomy at much later periods than those in which the most celebrated philosophers of Greece flourished, must have been very limited and erroneous, on account of the defectiveness of their instruments. And, added to the great disadvantages arising from this cause, the ancients laboured under the want of a knowledge of the telescope and the clock; and also maintained a false notion of the system of the world; which was almost universally adhered to, until the revival and improvement of the Pythagorean system by Copernicus, who died in 1543. Within the last two hundred years, but, particularly, since the laws of nature have been made manifest by the labours and discoveries of the immortal Newton, the science of astronomy has made astonishing advances towards perfection.