History Of Egypt, Chaldea, Syria, Babylonia, and Assyria, Vol. 3 — 40 - Ch. 3: Chaldaean Civilization, pt. 13

Drawn by Faucher-Gudin, from a sketch by Peiser.

It was a question in ancient times whether they or the Egyptians had been the first to carry their investigations into the infinite depths of celestial space: when it came to be a question as to which of the two peoples had made the greater progress in this branch of knowledge, all hesitation vanished, and the pre-eminence was accorded by the ancients to the priests of Babylon rather than to those of Heliopolis and Memphis.

* * Clement of Alexandria, Lucien, Diogenes Laertius, Macrobius, attribute the origin of astronomy to the Egyptians, and Diodorus Sioulus asserts that they were the teachers of the Babylonians; Josephus maintains, on the contrary, that the Egyptians were the pupils of the Chaldaeans.

[Illustration: 340. jpg ASTRONOMICAL TABLE] The Chaldaeans had conducted astronomical observations from remote antiquity.

* Callisthenes collected and sent to his uncle Aristotle a number of these observations, of which the oldest had been made nineteen hundred and three years before his time--that is, about the middle of the twenty-third century before our era: he could have transcribed many of a still earlier date if the archives of Babylon had been fully accessible to him.

* Epigenes asserts that their observations extended back to 720,000 years before the time of Alexander, while Berossus and Critodemus limit their antiquity to 490,000 years, which was further reduced to 473,000 years by Diodorus, to 470,000 by Cicero, and to 270,000 by Hipparchus.

The Chaldaean priests had been accustomed from an early date to record on their clay tablets the aspect of the heavens and the changes which took place in them night after night, the appearance of the constellations, their comparative brilliancy, the precise moments of their rising and setting and culmination, together with the more or less rapid movements of the planets, and their motions towards or from one another.

To their unaided eyes, sharpened by practice and favoured by the transparency of the air, many stars were visible, as to the Egyptians, which we can perceive only by the aid of the telescope.

These thousands of brilliant bodies, scattered apparently at random over the face of the sky, moved, however, with perfect regularity, and the period between their departure from and their return to the same point in the heavens was determined at an early date: their position could be predicted at any hour, their course in the firmament being traced so accurately that its various stages were marked out and indicated beforehand.

The moon, they discovered, had to complete two hundred and twenty-three revolutions of twenty-nine days and a half each, before it returned to the point from which it had set out.

This period of its career being accomplished, it began a second of equal length, then a third, and so on, in an infinite series, during which it traversed the same celestial houses and repeated in them the same acts of its life: all the eclipses which it had undergone in one period would again afflict it in another, and would be manifest in the same places of the earth in the same order of time.

* Whether they ascribed these eclipses to some mechanical cause, or regarded them as so many unfortunate attacks made upon Sin by the seven, they recognized their periodical character, and they were acquainted with the system of the two hundred and twenty-three lunations by which their occurrence and duration could be predicted.

Further observations encouraged the astronomers to endeavour to do for the sun what they had so successfully accomplished in regard to the moon.

* This period of two hundred and twenty-three lunations is that described by Ptolemy in the fourth book of his “Astronomy,” in which he deals with the average motion of the moon.

The Chaldaeans seem not to have been able to make a skilful use of it, for their books indicate the occurrence of lunar eclipses outside the predicted periods.

No long experience was needed to discover the fact that the majority of solar eclipses were followed some fourteen days and a half after by an eclipse of the moon; but they were unable to take sufficient advantage of this experience to predict with certainty the instant of a future eclipse of the sun, although they had been so struck with the connection of the two phenomena as to believe that they were in a position to announce it approximately.

* They were frequently deceived in their predictions, and more than one eclipse which they had promised did not take place at the time expected:** but their successful prognostications were sufficiently frequent to console them for their failures, and to maintain the respect of the people and the rulers for their knowledge.

Their years were vague years of three hundred and sixty days.

The twelve equal months of which they were composed bore names which were borrowed, on the one hand, from events in civil life, such as “Simanu,” from the making of brick, and “Addaru,” from the sowing of seed, and, on the other, from mythological occurrences whose origin is still obscure, such as “Nisanu,” from the altar of Ea, and “Elul,” from a message of Ishtar.

The adjustment of this year to astronomical demands was roughly carried out by the addition of a month every six years, which was called a second Adar, Blul, or Nisan, according to the place in which it was intercalated.

* Tannery is of opinion that the Chaldaeans must have predicted eclipses of the sun by means of the period of two hundred and twenty-three lunations, and shows by what a simple means they could have arrived at it.

** An astronomer mentions, in the time of Assurbanipal, that on the 28th, 29th, and 30th of the month he prepared for the observation of an eclipse; but the sun continued brilliant, and the eclipse did not take place.

The neglect of the hours and minutes in their calculation of the length of the year became with them, as with the Egyptians, a source of serious embarrassment, and we are still ignorant as to the means employed to meet the difficulty.

The months had relations to the signs of the zodiac, and the days composing them were made up of twelve double hours each.

The Chaldaens had invented two instruments, both of them of a simple character, to measure time--the clepsydra and the solar clock, the latter of which in later times became the source of the Greek “polos.

” The sun-dial served to determine a number of simple facts which were indispensable in astronomical calculations, such as the four cardinal points, the meridian of the place, the solstitial and equinoctial epochs, and the elevation of the pole at the position of observation.

The construction of the sundial and clepsydra, if not of the polos also, is doubtless to be referred back to a very ancient date, but none of the texts already brought to light makes mention of the employment of these instruments.

* * Herodotus (ii.

109) formally attributes the invention of the sun-dial and polos to the Babylonians.

The “polos” was a solar clock.

It consisted of a concave hemisphere with a style rising from its centre: the shadow of the style described every day an arc of a circle parallel to the equator, and the daily parallels were divided into twelve or twenty-four equal parts.

Smith discovered, in the palace of Sennacherib at Koyunjik, a portion of an astrolabe, which is now in the British Museum.

All these discoveries, which constitute in our eyes the scientific patrimony of the Chaldaeans, were regarded by themselves as the least important results of their investigations.

Did they not know, thanks to these investigations, that the stars shone for other purposes than to lighten up the nights--to rule, in fact, the destinies of men and kings, and, in ruling that of kings, to determine the fortune of empires?

Their earliest astronomers, by their assiduous contemplation of the nightly heavens, had come to the conclusion that the vicissitudes of the heavenly bodies were in fixed relations with mundane phenomena and events.

If Mercury, for instance, displayed an unusual brilliancy at his rising, and his disk appeared as a two-edged sword, riches and abundance, due to the position of the luminous halo which surrounded him, would be scattered over Chaldaea, while discords would cease therein, and justice would triumph over iniquity.

The first observer who was struck by this coincidence noted it down; his successors confirmed his observations, and at length deduced, in the process of the years, from their accumulated knowledge, a general law.

Henceforward, each time that Mercury assumed the same aspect it was of favourable augury, and kings and their subjects became the recipients of his bounty.

As long as he maintained this appearance no foreign ruler could install himself in Chaldaea, tyranny would be divided against itself, equity would prevail, and a strong monarch bear sway; while the landholders and the king would be confirmed in their privileges, and obedience, together with tranquillity, would rule everywhere in the land.

The number of these observations increased to such a degree that it was found necessary to classify them methodically to avoid confusion.

Tables of them were drawn up, in which the reader could see at one and the same moment the aspect of the heavens on such and such a night and hour, and the corresponding events either then happening, or about to happen, in Chaldaean, Syria, or some foreign land.

If, for instance, the moon displayed the same appearance on the 1st and 27th of the month, Elam was threatened; but “if the sun, at his setting, appears double his usual size, with three groups of bluish rays, the King of Chaldaea is ruined.

” To the indications of the heavenly bodies, the Chaldaeans added the portents which could be deduced from atmospheric phenomena: if it thundered on the 27th of Tammuz, the wheat-harvest would be excellent and the produce of the ears magnificent; but if this, should occur six days later, that is, on the 2nd of Abu, floods and rains were to be apprehended in a short time, together with the death of the king and the division of his empire.

It was not for nothing that the sun and moon surrounded themselves in the evening with blood-red vapours or veiled themselves in dark clouds; that they grew suddenly pale or red after having been intensely bright; that unexpected fires blazed out on the confines of the air, and that on certain nights the stars seemed to have become detached from the firmament and to be falling upon the earth.

These prodigies were so many warnings granted by the gods to the people and their kings before great crises in human affairs: the astronomer investigated and interpreted them, and his predictions had a greater influence than we are prepared to believe upon the fortunes of individuals and even of states.

The rulers consulted and imposed upon the astronomers the duty of selecting the most favourable moment for the execution of the projects they had in view.

From an early date each temple contained a library of astrological writings, where the people might find, drawn up as in a. code, the signs which bore upon their destinies.

One of these libraries, consisting of not less than seventy clay tablets, is considered to have been first drawn up in the reign of Sargon of Agade, but to have been so modified and enriched with new examples from time to time that the original is well-nigh lost.

This was the classical work on the subject in the VIIth century before our era, and the astronomers-royal, to whom applications were accustomed to be made to explain a natural phenomenon or a prodigy, drew their answers ready-made from it.

Astronomy, as thus understood, was not merely the queen of sciences, it was the mistress of the world: taught secretly in the temples, its adepts--at least, those who had passed through the regular curriculum of study which it required--became almost a distinct class in society.

The occupation was a lucrative one, and its accomplished professors had numerous rivals whose educational antecedents were unknown, but who excited the envy of the experts in their trading upon the credulity of the people.

These quacks went about the country drawing up horoscopes, and arranging schemes of birthday prognostications, of which the majority were without any authentic warranty.

The law sometimes took note of the fact that they were competing with the official experts, and interfered with their business: but if they happened to be exiled from one city, they found some neighbouring one ready to receive them.