ERA OF THE GREEK AND ALEXANDRIAN SCHOOLS. 3 



At the time of the capture of the city by Alexander, his tutor, the philosopher Aris 

 totle, is said by one of his commentators to have received from Callisthenes a catalogue of 

 eclipses observed there during a previous period of 1903 years. Though there may be con 

 siderable exaggeration here, yet there is, no doubt, substantial truth in the statement, since 

 Ptolemy gives six Chaldean eclipses, which seem to have been taken from the catalogue, 

 the earliest of which, however, goes no farther back than the year 720 B. c., answering to 

 about the time of the first captivity of the Jews. A comparison of these ancient with 

 modern observations led Halley to the discovery of the doctrine of the moon's accelera 

 tion that is, that she now moves round the earth with greater velocity than formerly, 

 the cause of which Laplace has satisfactorily explained. Ptolemy distinctly refers to 

 Chaldea as furnishing the best and most numerous astronomical observations ; and Cleo- 

 medes, speaking of a peculiar eclipse of the moon, states that " no astronomer, whether 

 Chaldean or Egyptian, has ever recorded one of this kind." It is remarkably illustrative 

 of the habit of diligent observation, that the Chaldeans were acquainted with the cycle of 

 6585^- days, during which the moon makes about 223 synodical revolutions, and experi 

 ences the same number of eclipses, alike too in order and magnitude, comparing cycle 

 with cycle. To them is attributed the invention of the zodiac and the duodecimal division 

 of the day. 



Superstition was the mainspring of that observance of celestial phenomena which pre 

 vailed at an early period in the regions bordering on the Euphrates. The heavenly bodies 

 were the objects of religious veneration. We can easily understand how, as the light of 

 the primitive revelation respecting the Supreme Ruler faded from the mind, men fell into 

 the error of regarding the glorious realities of the firmament as the governing intelligences 

 of the world. Their uses in the economy of the universe ; their resplendence and incom 

 prehensible character, to the untutored observer ; their elevation and far removal from 

 man ; their regular disappearance and return ; their stability and undiminished lustre ; 

 these are circumstances upon which popular ignorance would be likely to fasten, convert 

 into intimations of intelligent existence, and establish thereby the worship of the stellar 

 orbs. Such, in subsequent ages, has been the effect of the impressive appeal, made by the 

 great lights of heaven to the physical eye, in the absence of information. Even in our day 

 many a savage falls prostrate before the rising sun, or honours with religious ceremony 

 the different phases of the moon. 



The supposed possibility of divining future events by the appearance of the heavens, 

 was another inducement by which the ancient mind was powerfully actuated to observe 

 the face of the sky a hollow but imposing superstition, springing out of the witnessed 

 regularity of the effects produced upon the face of nature by the heavenly bodies. The 

 apparent varying altitude of the sun, at different times of the year, affecting the earth with 

 different degrees of heat as his rays are more or less oblique, producing thereby the pheno 

 mena of the seasons, was one of the physical facts open to the notice of the early observers. 

 They saw not only the day and night of the world, but the summer and winter of the world's 

 year, through which vegetation quickens, flourishes, and dies, determined by the move 

 ments of a mighty luminary in the firmament ; and the supposition was not unnatural, 

 in a connection so close and marvellous, that the sun was an intelligent body appearing in 

 certain positions to prognosticate certain events. The office supposed to be performed 

 by one of the heavenly bodies was also assigned to the rest, and the connection observed 

 between them with the changes upon the surface of the earth was likewise extended to 

 every class of circumstances, even the physical and moral qualities of men ; and thus, in 

 the observation of effects regularly occurring, their true causes overlooked, but being 

 plainly dependent upon celestial appearances, the art of judicial astrology had its origin. 

 The Chaldean priests marked the position of the stars in their courses, and of the moon 



