ERA OF THE GREEK AND ALEXANDRIAN SCHOOLS. 5 



The sculptured planisphere of the temple of Denderah, discovered by the scientific men 

 of the French expedition, and supposed to represent the appearance of the heavens at 

 midnight on the summer solstice, about seven centuries prior to the Christian era, is now 

 well known to be a work as recent as the time of the Roman empire. Upon the whole, 

 we have reason to suppose that the astronomy of the ancient oriental nations made no ad- 

 vances beyond that tolerably exact knowledge of the mean motions of the sun and moon 

 which the purposes of agriculture required, that it chiefly dealt with the simple observ- 

 ation of eclipses, occupations, and the rising and setting of principal stars, which was the 

 work of a priesthood who made it subservient to the consolidation of their superstition, 

 and that the idea of a cultivated science existing in times of venerable antiquity, the 

 hypothesis of some philosophers half a century ago, is without foundation. 



The decimal divisions of the sun's apparent path in the heavens, upon each of which 

 imagination has stamped an earthly figure ; with the arrangement of the extra-zodiacal 

 signs ; date their origin from a remote period, but both era and authors are lost in the mists 

 of ancient time. However inconvenient their use, and undesirable, on other grounds, their 

 retention in the present day, there was a moral grandeur in the idea of registering in the 

 skies the wild legends of mythology, and writing upon the imperishable vault of heaven 

 the customs and events of earth all so surely liable to change and to oblivion. The 

 grouping of the stars into constellations, to which definite names and figures are attached, 

 had an oriental commencement, though subsequently the Greeks and Romans largely 

 altered and amplified the work of their predecessors. It is not an improbable surmise, that 

 the figures of the zodiac have some relation to the rural occupations of the ancients, or to 

 the phenomena presented by the sun. Thus, the figure of a ram is supposed to have been 

 assigned to the assemblage of stars forming the first constellation, because of the sun 

 being in that part of the heavens at the season when the flocks were taken from the 

 stables to the fields. Thus, also, the lion was chosen to represent the fierceness of the 

 solar heat in summer ; the scorpion, to indicate the unhealthiness of autumn ; and the 

 balance, to express the equilibrium, or equal length of the days and nights, at the same 

 period. While the Greeks and Romans retained the zodiacal constellations, derived from 

 remoter antiquity, they constituted, as extra-zodiacal, images having a special reference to 

 their own history the figures of heroes, and the emblems of their deeds, over whose 

 existence hang the clouds of fable, or upon whose reported character rest the blots of 

 shame. It must, however, be acknowledged that the moderns are scarcely in circum- 

 stances to blame this proceeding, having contributed themselves to make confusion worse 

 confounded by adding to the motley assemblage of celestial signs. A place in the 

 heavens has been given to the shield of Sobieski, the sceptre of Brandenburg, the crown 

 of Frederick, the heart of Charles the First, and one was proposed for Napoleon in the 

 height of his guilty greatness. 



The age of astronomy in Greece commenced in the seventh century previous to our 

 era ; but in the writings of the older poets, Hesiod and Homer, some centuries earlier, allu- 

 sions occur which show that the appearance of particular stars and groups had been care- 

 fully noted. The former mentions the Pleiades remaining invisible for forty days, which 

 has been found to be as accurate as possible for his epoch and latitude. In precepts con- 

 cerning rural affairs, he advises the sickle to be applied to the ripened corn at the heliacal 

 rising of the cluster, and the ground to be ploughed at its heliacal setting. Now, sup- 

 posing that he lived about nine centuries before Christ, the era usually given, it is ascer- 

 tained, by astronomical formulae, that the heliacal rising of the Pleiades took place at a 

 time of the year corresponding to about our seventh of May, so that the harvest in Greece 

 is now a month later than it was then. It is also found that their heliacal setting would 

 be at a period answering to our twenty -ninth of March. The interval between the two 



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