much the same thing. So that it might well be expected, that where such a science was so much studied it ought to have been proportionably cultivated. Notwithstanding all which it does appear, that there was nothing done by the Chaldeans older than about four hundred years before Alexander's conquest, which could be serviceable either to Hipparchus or Ptolomy, in their determination of the celestial motions; for had there been any observations older than those we have, it cannot be doubted but the victorious Greeks must have procured them as well as those they did, they being still more valuable for their antiquity. All we have of them is only seven eclipses of the Moon preserved in Ptolomy's Syntaxis; and even those are very coarsely set down, and the oldest not much above seven hundred years before Christ; so that, after all the fame of these Chaldeans, we may be sure that they had not gone far in this science. And though Callisthenes is said by Porphyry to have brought from Babylon to Greece observations above one thousand nine hundred years older than Alexander, yet the proper authors making no mention or use of any such, renders it justly suspected for a fable. What the Egyptians did in this matter is less evident, because no one observation made by them can be found in their countryman Ptolomy, except what was done by the Greeks of Alexandria, under three hundred years

1. Callisthenes's account may not be a fable; the subsequent authors neither mentioned nor used these observations, because they were in truth such sorry ones, that no use could be made of them,

before Christ. Therefore, whatever was the learning of these two ancient nations, respecting the motions of the stars, it seems to have been chiefly theoretical ; and I will not deny, but some of them might very long since be apprised of the Sun's being the centre of our system, for such was the doctrine of Pythagoras aud Philolaus, and some others, who were said to have travelled into these parts.

"From hence it may appear, that the Greeks were the first practical astronomers, who endeavored in earnest to make themselves masters of the science, and to whom we owe all the old observations of the planets, and of the Equinoxes and Tropics. Thales was the first who could predict an eclipse in Greece, not six hundred years before Christ; and without doubt it was but a rude account he had of the motions; and it was Hipparchus who made the first catalogue of the fixed stars, not above one hundred and fifty years before Christ; without which catalogue there could be scarce such a science as astronomy; and it is to the subtilty and diligence of that great author, that the world was beholden for all its astronomy for above one thousand five hundred years. All that Ptolomy did, in his Syntaxis, was no more than a bare transcription of the theories of Hipparchus, with some little emendation of the periodical motions, after about three hundred years interval; and this book of Ptolomy was, without dispute, the utmost perfection of the ancient astronomy; nor was there any thing in any nation before it comparable thereto; for which reason all the other authors thereof were disregarded and lost, and

among them Hipparchus himself. Nor did posterity dare to altar the theories delivered by Ptolomy, though successively Albategnius and the Arabs, and after them the Spanish astronomers under Alphonsus endeavored to mend the errors which they observed in their computations. But their labors were fruitless, whilst from the defects of their principles it was impossible to reconcile the Moon's motion within a degree, nor the planets Mars and Mercury to a much greater space."

1

In confirmation of the above we remark, that the early Egyptian and Babylonian astronomers, with those of the Medes, all failed in affixing any definite data for the measurement of solar time. Indeed, the first recorded effort to this end was that of "Assis, a king of Thebes, in Egypt, who reigned about a thousand years after the flood," at which time the civil year was made to consist of three hundred and sixtyfive days. The Egyptians were followed by the Babylonians; but their year counted only three hundred and sixty days, till after the commencement of the reign of Belus, or Nabonassar, about sixteen hundred years after the flood. Hence the commencement of the Nabonassarean Era, the years of which agree exactly with the Egyptian, except that the former commences in winter, the latter in autumn; and "the ancient

1. See Plat. de Placit Philos, 1. ii., c. 8; 1. iii., c. 12. 1. iv., c. 18 and Plato Polit., p. 174, 175, 269, 270, 271; and Laert. in vit. Anax. 1., ix., seg. 33. (Shuck. vol. i., p. 8.)

year of the Medes is the same with the Nabonassa

rean." 1

The Brazen Age. next to the time of Jupiter; 2 and the Era of Sesostins, not being material to our present purpose, will be passed over without further notice.

Of the progress of astronomy, in determining the fractions of a year over three hundred and sixty-five days, if reliance is to be placed upon Dr. Hally's statement of the ancient astronomers as above, Thales, the Grecian philosopher, who flourished about the fiftieth year of the Nabonassarean Era, was the first of that nation who attempted to correct the Greek year. "He learned in Egypt that the year consisted of three hundred and sixty-five days." But even this correction was not immediately received all over Greece; for Solon, in the time of Cræsus, king of Lydia, was ignorant of it." It was, according to Strabo, reserved for Plato and Eudoxus, near two hundred years after the time of Thales, to find out the deficiency of almost six hours in his year; and, even this improvement, Dr. Hally states that before Hipparchus, who flourished only about one hundred and fifty years before Christ, there could be scarce such a science as astronomy, he having made the first catalogue of the fixed stars, such a catalogue being indispensable to minute astronomical calculations; and that to him the

1. Shuck. vol i., p. 9.
3. Ibid., p. 125.

5. Strabo 2. xvii., p. 806.

2. Shuck. Con. vol. iii. 78.
4. Ibid., Con. vol. i., p. 10.

world was beholden for all its astronomy for above one thousand five hundred years. Finally, as the learned astronomer Hally states, it was reserved for Ptolomy, in his Syntaxis, about three hundred years after Hipparchus, to carry that science, as based upon his theory, to the highest point of perfection that it ever attained under the ancients.

From the preceding, however, it is evident that the Greeks were by no means the "pioneers" of astronomical science. In fact, their earliest mode of chronological computations, was by generations, three of which, at thirty-three and one-third years each, equalled one hundred years. Hence, Pherecydes and Cadmus, of Miletus, the two most ancient historians of the Greeks, who flourished about five hundred years before Christ; and sometimes, even Herodotus,' who, by the way, furnishes a rule by which to determine said computations, adopted "this very natural, but very indefinite mode." Newton, in his "chronologia veterum emendata," however, only allows from eighteen to twenty years, as the average of the reigns of their kings, three of which, at sixty-six years, makes a difference from the above of thirty-four years; while on the other hand, Eratosthenes and Apollodorus, fixes the average of each generation at thirty-six and a half years.

The science of astronomy among the Greeks, between the times of Solon and Hipparchus, a period of about four hundred and forty years, was exceedingly

1. Herodotus, 1. i., p. 184.

2. Ibid, 1. ii., p. 144.