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HISTORICAL VIEW OF THE

persecution, at the hands either of people or rulers,equally incapable of appreciating their value. If, how-ever, some motive were assigned more level to the appre-hensions of the vulgar, and especially one connected withtheir superstitions, this would at once secure their re-spect and enhance their reverence for the individual en-gaged with such lofty objects.

Several ancient nations have laid claim to consider-able advances in astronomy at periods of antiquity farbeyond reasonable probability. Thus the Chinese andthe Indians each refer to a date of about 3000 yearsbefore the Christian era, as that to which their astro-nomical records reach, and the Chaldeans to morethan 2000 years. But though these extravagant claimsare unsupported by evidence, and at variance with allprobability, we have still good grounds for consideringthe science to have made some progress among thesenations upwards of 1000 years before our era.

The Chaldeans.

The antiquity of the Chaldean astronomy rests uponthe authority of Porphyry, who says that Callisthenes transmitted to Aristotle a series of observations madeat Babylon , during a period of 1,003 years precedingthe capture of that city by Alexander, or reaching backto about 2234 b. c. Ptolemy , however, who afterwardsmade great use of them, quotes none prior to 720 b. c.This certainly is not conclusive against the existenceof any of earlier date, though it doubtless furnishes astrong presumption.

These early observations, though probably but of arude description, yet possess a peculiar interest as hav-ing furnished the first materials for those comparisonsof the state of the heavens at distant periods, by whichthe great progressive changes in our system have beenbrought to light.

The Chaldeans appear to have found, with consider-able accuracy, the length of the remarkable cycle of6585} days or about 18 years, in which the series of