Part 11

They would, therefore, have to search in the heavens for an apparent sign of its return, and they imagined they had found this sign when the sun returned to the same position, relatively to some remarkable star. Thus they applied themselves, like almost all nations who are beginning this inquiry, to observe the heliacal risings and settings of the stars. We know that they chose particularly the heliacal rising of Sirius, at first, doubtless, on account of the beauty of the star; and, especially, because, in those ancient times, this rising of Sirius being nearly coincident with the solstice, and indicative of the inundation, was to them the most important phenomenon of this kind. Hence it was that Sirius, under the name of Sothis, occupied so conspicuous a place in their mythology, and in their religious ceremonies. Supposing, therefore, that the return of the heliacal rising of Sirius and the tropical year were of the same duration, and believing, at length, that this duration was 365 days and a quarter, they would imagine a period after which the tropical year and the old year, the sacred year of 365 days only, would return to the same day; a period which, according to these incorrect data, was necessarily 1461 sacred years, and 1460 of those improved years to which they gave the name of years of Sirius.

They took for the point of departure of this period, which they named the Sothiac or great year, a civil year, the first day of which was, or had been, also that of a heliacal rising of Sirius; and it is known, from the positive testimony of Censorinus, that one of these great years had ended in the 138th year of the Christian era[182]. It had consequently commenced in the 1322d before Christ, and that which preceded it in the 2782d. In fact, the calculations of M. Ideler shew, that Sirius was heliacally risen on the 20th July of the Julian year 139, a day which corresponded that year to the first of Thot, or the first day of the Egyptian sacred year[183].

But not only is the position of the sun, with relation to the stars of the ecliptic, or the sidereal year different from the tropical year, on account of the precession of the equinoxes. The heliacal year of a star, or the period of its heliacal rising, especially when it is distant from the ecliptic, differs still from the sidereal year, and differs in various degrees according to the latitudes of the places where it is observed. What is very singular, however, and the observation has already been made by Bainbridge[184] and Father Petau[185], it happens, by a remarkable concurrence in the positions, that, in the latitude of Upper Egypt, at a certain epoch, and during a certain number of ages, the year of Sirius was really within very little of 365 days and a quarter; so that the heliacal rising of this star returned in fact to the same day of the Julian year, the 20th July, in the year 1322 before, and the year 138 after Christ[186].

From this actual coincidence, at this remote period, M. Fourier, who has confirmed all these accounts by new calculations, concludes, that, since the length of the year of Sirius was so perfectly known to the Egyptians, they must have determined it by observations made during a long series of years, and conducted with great accuracy; observations which must be referred to at least 2500 years before the present time, and which could not have been made long before or long after this interval of time[187].

This result would assuredly be very striking, had it been directly, and by observations, made upon Sirius itself, that they had fixed the length of the year of Sirius. But experienced astronomers affirm it to be impossible that the heliacal rising of a star could afford a sufficient foundation for exact observations on such a subject, especially in a climate where _the circumference of the horizon is constantly so much loaded with vapours, that, in clear nights, stars of the second or third magnitude can never be seen within some degrees of the verge of the horizon, and that the sun itself is completely obscured at its rising and setting_.[188] They maintain, that, if the length of the year had not been otherwise ascertained, there would have been a mistake of one or two days.[189] They have no doubt, therefore, that this duration of 365 days and a quarter, is that of the tropical year inaccurately determined by the observation of the shadow, or by that of the point where the sun rose each day, and through ignorance identified with the heliacal year of Sirius; so that it would be mere chance which had fixed with so much accuracy the duration of this latter for the period of which we speak.[190]

Perhaps it will also be judged, that men capable of making observations so exact, and which they had continued during so long a period, would not have attributed so much importance to Sirius, as to pay him religious homage; for they would have seen that the relations of the rising of this star with the tropical year, and with the inundation of the Nile, were merely temporary, and took place only in a determinate latitude. In fact, according to M. Ideler’s calculations, in the year 2782 before Christ, Sirius appeared in Upper Egypt, on the second day after the solstice; in 1322, on the third; and in the year 139 after Christ, on the twenty-sixth.[191] At the present day, its heliacal rising is more than a month after the solstice. The Egyptians would therefore set themselves by preference to finding the period, which would bring about the coincidence of the commencement of the sacred year, with that of the true tropical year, and then they would discover that their great period must have been 1508 sacred years, and not 1461.[192] Now, we assuredly do not find any traces of this period of 1508 years in antiquity.

In general, we may defend ourselves with the idea, that, if the Egyptians had possessed so long a series of observations, and of accurate observations too, their disciple Eudoxus, who studied among them for thirteen years, would, on his return, have brought into Greece a system of astronomy more perfect, and maps of the heavens less erroneous, and more coherent in their different parts.[193] How should it happen that the precession of the equinoxes was not known to the Greeks, but through the works of Hipparchus, if it had been marked in the registers of the Egyptians, and inscribed in characters so manifest upon the ceilings of their temples? And how comes it that Ptolemy, who wrote in Egypt, should not have deigned to avail himself of any of the observations of the Egyptians?[194]

Farther, Herodotus, who lived so long with them, says nothing of those six hours which they added to the sacred year, nor of that great Sothian period which resulted. On the contrary, he says expressly that the Egyptians, making their year of 365 days, the seasons returned to the same point, so that in his time the necessity of this quarter of a day does not appear to have been suspected.[195] Thalles, who had visited the priests of Egypt, less than a century before Herodotus, did not, in like manner, make known to his countrymen, any other than a year of 365 days only.[196] And, if we reflect that all the colonies which migrated from Egypt, fourteen or fifteen centuries before Christ, the Jews and the Athenians, carried with them the lunar year, it will perhaps be inferred that the year of 365 days itself had not existed in Egypt in these remote ages.

I am aware that Macrobius[197] gives the Egyptians a solar year of 365¼ days; but this author, who is comparatively modern, and who lived at a long period after the establishment of the fixed year of Alexandria, must have confounded the epochs. Diodorus[198] and Strabo[199] only attribute such a year to the Thebans; they do not say that it was in general use, and they themselves did not live till long after Herodotus.

Thus the Sothian or great year must have been a comparatively recent invention, since it results from the comparison of the civil year with this pretended heliacal year of Sirius; and it is for this reason that it is only spoken of in the works of the second and third century after Christ[200], and that Syncellus alone, in the ninth, seems to cite Manetho as having made mention of it.

Notwithstanding all that is said to the contrary, the same opinion must be formed of the astronomical knowledge of the Chaldeans. It is natural enough to think, that a people who inhabited vast plains, under a sky perpetually serene, must have been led to observe the course of the stars, even at a period when they still led a wandering life, and when the stars alone could direct their courses during the night; but since what period were they astronomers, and to what perfection did they carry the science? Here rests the question. It is generally allowed that Callisthenes sent to Aristotle observations made by them, and which referred to a period of 2200 years before Christ; but this fact is related only by Simplicius[201], as stated upon the authority of Porphyry, and 600 years after Aristotle. Aristotle himself says nothing on the subject, nor has any creditable astronomer spoken of it. Ptolemy mentions and makes use of ten observations of eclipses really made by the Chaldeans; but they do not refer to an earlier period than that of Nabonassar (721 years before Christ); they are inaccurate also; the time is expressed only in hours and half-hours, and the shadow only in halves or fourths of the diameter. Notwithstanding, as they had fixed dates, the Chaldeans must have had some knowledge of the true length of the year, and some means of measuring time. They appear to have known the period of eighteen years, which brings back the eclipses of the moon in the same order; a piece of knowledge which the mere inspection of their registers would promptly afford them; but it is certain that they could neither explain nor predict eclipses of the sun.

It is from not having sufficiently understood a passage of Josephus, that Cassini, and after him Bailly, have imagined that they discovered in it a luni-solar period of 600 years, which had been known from the time of the first patriarchs[202].

Thus every thing leads us to believe that the great reputation of the Chaldeans was given them at a more recent period, by their unworthy successors, who, under the same name, sold their horoscopes and predictions throughout the whole Roman empire, and who, in order to procure themselves more credit, attributed to their rude ancestors the honour of the discoveries of the Greeks.

With regard to the Indians, every body knows that Bailly, believing that the epoch which is used as a period of departure in some of their astronomical tables had been actually observed, has attempted to draw from thence a proof of the great antiquity of the science among this people, or at least among the nation which had bequeathed them its knowledge. But the whole of this system, invented with so much labour, falls to the ground of itself, now that it is proved that this epoch has been adopted but of late, from calculations made backwards, and even false in their results.[203]

Mr Bentley has discovered that the tables of Tirvalour, on which the assertion of Bailley especially rested, must have been calculated about 1281 of the Christian era, or 540 years ago, and that the Surya-Siddhanta, which the Brahmins regard as their oldest scientific treatise on astronomy, and which they pretend to have been revealed upwards of 20,000,000 of years ago, could not have been composed at an earlier period than about 760 years from the present day[204].

Solstices and equinoxes indicated in the Pouranas, and calculated according to the positions which seem to be attributed to them by the signs of the Indian zodiac, such as they are supposed to be, have acquired the character of an enormous antiquity. A more attentive examination of these signs or nacchatras has lately convinced M. de Paravey that reference is only made to solstices of 1200 years before the Christian era. This author at the same time admits, that the place of the solstices is so inaccurately fixed, that this determination of their date must be received with a latitude of 200 or 300 years. They are in the same predicament as those of Eudoxus and of Tcheoukong[205].

It is ascertained that the Indians do not make observations, and that they are not in possession of any of the instruments necessary for that purpose. M. Delambre indeed admits, with Bailly and Legentil, that they have processes of calculation, which, without proving the antiquity of their astronomy, shew at least its originality[206]; and yet this conclusion can by no means be extended to their sphere; for, independently of their twenty-seven nacchatras or lunar houses, which strongly resemble those of the Arabians, they have the same twelve constellations in the zodiac as the Egyptians, Chaldeans, and Greeks[207]; and, if we refer to Mr Wilfort’s assertions, their extra-zodiacal constellations are also the same as those of the Greeks, and bear names which are merely slight alterations of their Greek names[208].

It is to Yao that the introduction of astronomy into China is attributed. He is represented, in the Chou-king, as sending astronomers toward the four cardinal points of his empire, to examine what stars presided over the four seasons, and to regulate the operations to be carried on at each period of the year[209], as if their dispersion was necessary for such an undertaking. About 200 years later, the Chou-king speaks of an eclipse of the sun, but accompanied with ridiculous circumstances, as in all the fables of this kind; for the whole Chinese army, headed by a general, is made to march against two astronomers, because they had not properly predicted it[210]; and it is well known that, more than 2000 years after, the Chinese astronomers possessed no means of accurately predicting the eclipses of the sun. In 1629 of our era, at the time of their dispute with the Jesuits, they did not even know how to calculate the shadows.

The real eclipses, recorded by Confucius in his Chronicle of the kingdom of Lou, commence only 1400 years after this, in the 776th before Christ, and scarcely half a century earlier than those of the Chaldeans related by Ptolemy. So true is it, that the nations which escaped at the same time from the general catastrophe, also arrived about the same period, when their circumstances have been similar, at the same degree of civilization. Now, it might be thought, from the identity of the names of the Chinese astronomers in different reigns (they appear, according to the Chou-king, to have all been named _Hi_ and _Ho_), that, at this remote epoch, their profession was hereditary in China, as it was in India, Egypt, and Babylon.

The only Chinese observation of any antiquity, which has nothing in itself to prove its want of authenticity, is that of the shadow made by _Tcheou-kong_ about 1100 years before Christ; and even it is far from being correct[211].

Hence our readers may conclude, that the inferences drawn from the alleged perfection of astronomical science among ancient nations, is not more conclusive in favour of the excessive antiquity of those nations, than the testimonies which they have adduced in reference to themselves.

But had this astronomy been more perfect, what would it prove? Has the progress been calculated which this science ought to make among nations who were not in any degree in possession of others; to whom the serenity of the sky, the necessities of the pastoral or agricultural life, and their superstitious ideas, would render the stars an object of general attention; where colleges, or societies of the most respectable men among them, were charged with keeping a register of interesting phenomena, and transmitting their memory; and where, from the hereditary nature of the profession, the children were brought up from the cradle in the knowledge of facts ascertained by their parents? Supposing that, among the numerous individuals of whom the cultivation of astronomy was the sole occupation, there should happen to be one or two possessed of extraordinary talents for geometry, all the knowledge acquired by these nations might be attained in a few centuries.

Since the time of the Chaldeans, real astronomy has only had two eras, that of the Alexandrian school, which lasted 400 years, and that of our own times, which has not existed so long. The learned period of the Arabians scarcely added any thing to it; and the other ages have been mere blanks with regard to it. Three hundred years did not intervene between Copernicus and the author of the _Mecanique Céleste_; and can it be believed that the Indians required thousands of years to arrive at their crude theories?

_The Astronomical Monuments left by the Ancients do not bear the excessively remote dates which have been attributed to them._

Recourse has therefore been had to arguments of another kind. It has been pretended that, independently of the knowledge which these nations may have acquired, they have left monuments which bear a date fixed by the state of the heavens which they represent, and one that refers to a very remote antiquity. The zodiacs sculptured in two temples of Upper Egypt, are adduced as furnishing proofs perfectly demonstrative of this assertion. They present the same figures of the zodiacal constellations as are employed at the present day, but distributed in a manner peculiar to themselves. The state of the heavens at the period when these monuments were delineated, is imagined to have been represented by this distribution, and it has been thought that it would be possible from it to infer the precise period at which the edifices containing them were erected[212].

But to arrive at the high antiquity which is supposed to be deducible from this, it must, in the _first_ place, be supposed, that their division has a determinate relation to a certain state of the heavens, dependent upon the precession of the equinoxes, which causes the colures to make the tour of the zodiac in 26,000 years; that it indicated, for example, the position of the solstitial point; and, _secondly_, that the state of the heavens represented was precisely that which took place at the period when the monument was erected,--two suppositions which themselves, as is evident, suppose a great number of others.

In point of fact, are the figures of these zodiacs the constellations,--the true groups of stars which at present bear the same names, or merely what astronomers call signs, that is to say, divisions of the zodiac proceeding from one of the colures, whatever place this colure occupies? Is the point at which these zodiacs have been divided into two bands, necessarily that of a solstice? Is the division of the side next the entrance, necessarily that of the summer solstice? Does this division indicate, even in general, a phenomenon dependent upon the precession of the equinoxes? Does it not refer to some period the rotation of which would be less; for example, to the moment of the tropical year when such or such sacred years of the Egyptians commenced, which, being shorter than the true tropical year by nearly six hours, would make the tour of the zodiac in 1508 years? Lastly, whatever signification it may have had, has it been intended by it to mark the time when the zodiac was sculptured, or that when the temple was built? Has not the object been to record a previous state of the heavens at some period which was interesting in a religious point of view, whether it had been actually observed, or inferred from a retrograde calculation?

From the mere announcement of such questions, it will be perceived how complicated they necessarily are, how much subject to controversy any solution that might be adopted on this subject would be, and how little qualified to serve as a solid proof, for the solution of another problem, such as the antiquity of the Egyptian nation. And it may be said, with regard to those who have attempted to infer a date from these data, that there have arisen as many opinions as there have been authors.

The learned astronomer Mr Burkhard, from a first examination, judged that, at Dendera, the solstice is marked by the Lion; which would make it two signs less remote than at the present day, and the temple at least 4000 years old[213]. He gave, at the same time an antiquity of 7000 years to that of Esne, although it is not known how he had purposed to reconcile these numbers with what we know of the precession of the equinoxes. The late M. Lalande, seeing that the Cancer was repeated on the two bands, imagined that the solstice passed to the middle of that constellation; but as this was the case also in the sphere of Eudoxus, he concluded that some Grecian artist might have represented this sphere on the ceiling of an Egyptian temple, without knowing that it represented a state of the heavens which no longer existed[214]. This, as is seen, was a conclusion very different from that of Mr Burkhard. Dupuis was the first who thought it necessary to search for proofs of the idea, in some measure confidently adopted, that it was the solstice that was denoted. He found them, with reference to the great zodiac of Dendera, in the globe on the top of the pyramid, and in several emblems placed near different signs, and which he imagined, sometimes according to the opinion of ancient authors, such as Plutarch, Horus Apollo, or Clement of Alexandria, sometimes according to his own conjectures, ought to be regarded as representing phenomena which had been really those of the seasons affected at each sign. As for the rest, he maintained that this state of the heavens affords the date of the monument, and that it is the original, and not a copy, of the sphere of Eudoxus, that was represented at Dendera, which would refer it to a period of 1468 years before Christ, or to the reign of Sesostris. The number of nineteen boats, however, placed under each band, furnished him with the idea that the solstice might probably have been at the nineteenth degree of the sign, which would make it 288 years older[215].

Mr Hamilton[216] having remarked, that, at Dendera, the Scarabæus belonging to the side of the ascending signs is smaller than that of the other side, an English author[217] has concluded from this that the solstice may have been nearer its actual point than the middle of the Cancer, which would carry us back to a period of 1000 or 1200 years before Christ.

The late M. Nouet, judging that the globe, the rays, and the horned head, or head of Isis, represent the heliacal rising of Sirius, supposed that it was intended to mark an epoch of the Sothian period, but that it was intended to mark it by the place which the solstice occupied. Now, in the last but one of these periods, that which elapsed between 2782 and 1322 before Christ, the solstice had passed from 30° 48′ of the constellation of the Lion to 13° 34′ of Cancer. At the middle of this period, it was therefore at 23° 34′ of cancer. The heliacal rising of Sirius happened then some days after the solstice; and this is nearly what has been indicated, according to M. Nouet, by the repetition of the Scarabæus, and by the figure of Sirius with the rays of the sun placed at the commencement of the band to the right. Calculating upon this basis, he concludes that the temple of Dendera was built 2052 years before Christ, and that of Esne 4600[218].