CHRONOLOGY
, the art of measuring and distinguishing time; with the doctrine of dates, epochs, eras, &c.
The measurement of time in the most early periods, was by means of the seasons, or the revolutions of the sun and moon. The succession of Juno's priestesses at Argos served Hellanicus for the regulation of his narrative; while Ephorus reckoned his matters by generations. Even in the histories of Herodotus and Thucydides, there are no regular dates for the events recorded; nor were there any endeavours to establish a fixed era until the time of Ptolomy Philadelphus, who attempted it by comparing and correcting the dates of the olympiads, the kings of Sparta, and the succession of the priestesses of Juno at Argos. Eratosthenes and Apollodorus digested the events related by them, according to the succession of the olympiads and of the Spartan kings.
The chronology of the Latins is still more uncertain. The records of the Romans were destroyed by the Gauls; and Fabius Pictor, the most ancient of their historians, was obliged to borrow the chief part of his information from the Greeks. In other European nations the chronology is still more imperfect, and of a later date: and even in modern times a considerable degree of confusion and inaccuracy has arisen, from the want of attention in the historians to ascertain the dates and epochs with precision.
Hence it is evident, how necessary a proper system of chronology must be for the right understanding of history, and also how difficult it must be to establish such a system. For this purpose, however, several learned men have spent much time, particularly Julius Africanus, Eusebius of Cæsarea, George Cyncelle, John of Antioch, Dennis, Petau, Clavius, Calvisius, Scaliger, Vieta, Newton, Usher, Simson, Marsham, Helvicus, Vossius, Strauchius, Blair, and Playfair.
Such a system is founded, 1st, On astronomical observations, especially of the eclipses of the sun and moon, combined with calculations of the years and eras of different nations. 2d, The testimonies of cre- dible authors. 3d, Such epochs in history as are so well attested and determined, that they have never been controverted. 4th, Ancient medals, coins, monuments, and insoriptions.
The most obvious division of time, as has been observed, is derived from the apparent or real revolutions of the luminaries, the sun and moon. Thus, the apparent revolution of the sun, or the real rotation of the earth on her axis causing the sun to appear to rise and set, constitutes the vicissitudes of day and night, which must be evident to the most barbarous and ignorant nations. The moon, by her revolution about the earth, and her changes, as naturally and obviously forms months; while the great annual course of the sun through the several constellations of the zodiac, points out the larger division of the year.
The Day is divided into hours, minutes, &c; while the month is divided into weeks, and the year into months, having particular names, and a certain number of days.—See a particular account of each of these under the respective words.
Beside the natural divisions of time arising immediately from the revolutions of the heavenly bodies, there are others which are formed from some of the less obvious consequences of these revolutions, and are called cycles, or circles. The most remarkable of these are, 1, The Solar Cycle, or cycle of the sun, a period or revolution of 28 years, in which time the days of the months return to the same days of the week, the sun's place to the same signs and degrees of the ecliptic on the same months and days, and the leap-years begin the same course over again with respect to the days of the week on which the days of the months fall. 2, The Lunar Cycle, or cycle of the moon, commonly called the Golden Number, is a revolution of 19 years; in which time the conjunctions, oppositions, and other aspects of the moon, are on the same days of the months as they were 19 years before, and within an hour and a half of the same time of the day.
The Indiction, or Roman Indiction, is a period of 15 years, used only by the Romans for indicating the times of certain payments made by the subjects to the republic.
The Cycle of Easter, called also the Dionysian Period, is a revolution of 532 years, and is produced by multiplying the solar cycle 28, by the lunar cycle 19.
The Julian Period, is a revolution of 7980 years, and is produced from the continual multiplication of the three numbers 28, 19, 15, of the three former cycles, viz, the solar, lunar, and indiction.
As there are certain fixed points in the heavens, from which astronomers begin their computations, so there are certain points of time, from which historians begin to reckon; and these points or roots of time are called eras or epochs. The most remarkable of these are, those of the Creation, the Greek Olympiads, the building of Rome, the era of Nabonnassar, the death of Alexander, the birth of Christ, the Arabian Hegira, or flight of Mahomet, and the Persian Jesdegird. All which, with some others of less note, have their beginnings fixed by chronologers to the years of the Julian period, to the age of the world, and to the years before and after the birth of Christ.
The testimony of authors is the second principal | part of historical chronology. Though no man has a right to be considered as infallible, it would however be making a very unfair judgment of mankind, to treat them all as dupes or impostors; and it would be an injury offered to public integrity, to doubt the veracity of authors universally esteemed, and facts that are truly worthy of belief. When the historian is allowed to be completely able to judge of an event, and to have no intent of deceiving by his relation, his testimony cannot be refused.
The Epochs form the 3d principal part of chronology; being those fixed points in history that have never been contested, and of which there cannot reasonably be any doubt. Notwithstanding that chronologers fix upon the events which are to serve as epochs, in a manner quite arbitrary; yet this is of little consequence, provided the dates of these epochs agree, and that there is no contradiction in the facts themselves.
Medals, Monuments, and Inscriptions, form the last of the four principal parts of chronology; and this study is but of very modern date, scarce more than 150 years having elapsed since close application has been made to the study of these. To the celebrated Spanheim we owe the greatest obligations, for the progress that is made in this method; and it is by the aid of medals that M. Vaillant has composed his judicious history of the kings of Syria, from the time of Alexander the Great to that of Pompey. Nor have they been of less service in elucidating all ancient history, especially that of the Romans; and even sometimes that of the middle ages.
Besides the foregoing general account, there are some few systems of chronology which may deserve some more particular notice, as follows.
Sacred Chronology. There have been various systems relating to sacred chronology; which is not to be wondered at, as the three chief copies of the Bible give a very different account of the first ages of the world. For while the Hebrew text reckons about 4000 years from the creation to the birth of Christ, and to the flood 1656 years; the Samaritan makes the former much longer, though it counts from the creation to the flood only 1307 years; and the Septuagint removes the creation of the world to 6000 years before Christ, and 2250 years before the flood. Many attempts have been made to reconcile these differences; though none of them are quite satisfactory. Walton and Vossius give the preference to the accountof the Septuagint; while others have defended the Hebrew text. See an abstract of the different opinions of learned men on this subject, in Strauchius's Brev. Chron. translated by Sault, p. 166 and 176.
The Chinese Chronology. No nation has boasted more of its antiquity than the Chinese: but though they be allowed to trace their origin as far back as the deluge, they have few or no authentic records of their history for so long a period as 500 years before the Christian era. This indeed may be owing to the general destruction of ancient remains by the tyrant Tsin-chi-hoang, in the year 213, or some say 246, before Christ. From a chronology of the Chinese history (for which we are obliged to an illustrious Tartar who was viceroy of Canton in the year 1724, and of which a Latin translation was published at Rome in 1730), we learn that the most remote epoch of the Chinese chronology does not surpass the first year of Guei-lie-wang, or 424 years before our vulgar era. And this opinion is confirmed by the practice of two of the most approved historians of China, who admit nothing into their histories previous to this period.
The Chinese, in their computation, make use of a cycle of 60 years, called kia-tse, from the name given to the first year of it, which serves as the basis of their whole chronology. Every year of this cycle is marked with two letters which distinguish it from the others; and all the years of the emperors, for upwards of 2000 years, have names in history common to them with the corresponding years of the cycle. Philos. Trans. Abridg. vol. 8, part 4, pag. 13.
According to M. Freret, in his Essays, the Chinese date the epocha of Yao, one of their first emperors, about the year 2145, or 2057, before Christ; and they reckon that their first astronomical observations, and the composition of their calendar, preceded Yao 150 years: from whence it is inferred that the era of their astronomical observations coincides with that of the Chaldeans. But later authors date the rise and progress of the sciences in China from the grand dynasty of Tcheou, about 1200 years before the Christian era, and shew that all historical relations of events prior to the reign of Yao are fabulous. Mem. de l'Histoire des Sciences &c. Chinois. vol. 1, Paris 1776.
Babylonian, Egyptian, and Chaldean Annals. These, M. Gibert has attempted to reduce to our chronology, in a letter published at Amsterdam in 1743. He begins with shewing, by the authorities of Macrobius, Eudoxus, Varro, Diodorus Siculus, Pliny, Plutarch, St. Augustin, &c, that by a year, the ancients meant the revolution of any planet in the heavens; so that it might consist sometimes of only one day. Thus, according to him, the solar day was the astronomical year of the Chaldeans; and so the boasted period of 473,000 years, assigned to their observations, is reduced to 1297 years 9 months; the number of years which, according to Eusebius, elapsed from the first discoveries of Atlas in astronomy, in the 384th year of Abraham, to the march of Alexander into Asia in the year 1682 of the same era. And the 17,000 years added by Berosus to the observations of the Chaldeans, reduced in the same manner, will give 46 years and 6 or 7 months; being the exact interval between Alexander's march, and the first year of the 123d Olympiad, or the time to which Berosus carried his history.
Epigenius ascribes 720,000 years to the observations preserved at Babylon; but these, according to M. Gibert's system, amount only to 1971 years 3 months; which differ from Callisthenes's period of 1903 years, allotted to the same observations, only by 68 years, the period elapsed from the taking of Babylon by Alexander, which terminated the latter account, and to the time of Ptolomy Philadelphus, to which Epigenius extended his account.
The Newtonian Principles of Chronology.—Sir Isaac Newton has shewn, that the chronology of ancient kingdoms is involved in the greatest uncertainty: that | the Europeans in particular had no chronology before the Persian empire, which commenced 536 years before the birth of Christ, when Cyrus conquered Darius the Mede: that the antiquities of the Greeks are full of fables, because their writings were in verse only, till the conquest of Asia by Cyrus the Persian; about which time prose was introduced by Pherecides Syrius and Cadmus Milesius. After this time several of the Greek historians introduced the computation by generations. The chronology of the Latins was still more uncertain: their old records having been burnt by the Gauls 120 years after the expulsion of their kings, or 64 years before the death of Alexander the Great, answering to 388 before the birth of Christ. The chronologers of Gaul, Spain, Germany, Scythia, Sweden, Britain, and Ireland, are of a still later date. For Scythia, beyond the Danube, had no letters till Ulphilas, their bishop, formed them, about the year 276. Germany had none till it received them from the western empire of the Latins, about the year 400. The Huns had none in the days of Procopius, about the year 526. And Sweden and Norway received them still later.
Sir Isaac Newton, after a general account of the obscurity and defects of the ancient chronology, observes that, though many of the ancients computed by successions and generations, yet the Egyptians, Greeks, and Latins, reckoned the reigns of kings equal to generations of men, and three of them to a hundred, and sometimes to 120 years; and this was the foundation of their technical chronology. He then proceeds, from the ordinary course of nature, and a detail of historical facts, to shew the difference between reigns and generations; and that, though a generation from father to son may at an average be reckoned about 33 years, or three of them equal to 100 years, yet, when they are taken by the eldest sons, three of them cannot be estimated at more than about 75 or 80 years; and the reigns of kings are still shorter; so that 18 or 20 years may be allowed a just medium. Sir Isaac then fixes on four remarkable periods, viz, the return of the Heraclidæ into the Peloponnesus, the taking of Troy, the Argonautic expedition, and the return of Sesostris into Egypt, after his wars in Thrace; and he settles the epoch of each by the true value of a generation. To instance only his estimate of that of the Argonautic expedition: Having fixed the return of the Heraclidæ to about the 159th year after the death of Solomon, and the destruction of Troy to about the 76th year after the same period, he observes, that Hercules the Argonaut was the father of Hyllus, the father of Clerdius, the father of Aristomachus, the father of Aristodemus, who conducted the Heraclidæ into Peloponnesus; so that, reckoning by the chief of the family, their return was four generations later than the Argonautic expedition, which therefore happened about 43 years after the death of Solomon. This is farther confirmed by another argument: Æsculapius and Hercules were Argonauts: Hippocrates was the 18th inclusively from the former by the father's side, and the 19th from the latter by the mother's side: now, allowing 28 or 30 years to each of them, the 17 intervals by the father, and the 18 intervals by the mo- ther, will on a medium give 507 years; and these, reckoning back from the commencement of the Peloponnesian war, or the 431st year before Christ, when Hippocrates began to flourish, will place the Argonautic expedition in the 43d year after the death of Solomon, or 937 years before Christ.
The other kind of reasoning by which Newton endeavours to establish this epoch, is purely astronomical. The sphere was formed by Chiron and Musæus for the use of the Argonautic expedition, as is plainly shewn by several of the asterisins referring to that event: and at the time of the expedition the cardinal points of the equinoxes and solstices were placed in the middle of the constellations Aries, Cancer, Chelæ, and Capricorn. This point is established by Newton from the consideration of the ancient Greek calendar, which consisted of 12 lunar months, and each month of 30 days, which required an intercalary month. Of course this lunisolar year, with the intercalary month, began sometimes a week or two before or after the equinox or solstice; and hence the first astronomers were led to the before-mentioned disposition of the equinoxes and solstices: and that this was really the case, is confirmed by the testimonies of Eudoxus, Aratus, and Hipparchus. Upon these principles Sir Isaac proceeds to argue in the following manner. The equinoctial colure in the end of the year 1689 cut the ecliptic in 6° 44′; and by this reckoning the equinox had then gone back 36° 44′ since the time of the Argonautic expedition. But it recedes 50′ in a year, or 1° in 72 years, and consequently 36° 44′ in 2645 years; and this, counted backwards from the beginning of 1690, will place this expedition about 25 years after the death of Solomon. But as there is no necessity for allowing that the middle of the constellations, according to the general account of the ancients, should be precisely the middle between the prima Arietis and ultima Caudæ, our author proceeds to “examine what were those stars through which Eudoxus made the colures to pass in the primitive sphere, and in this way to fix the position of the cardinal points.” Now from the mean of five places he finds, that the great circle, which in the primitive sphere, described by Eudoxus, or which at the time of the Argonautic expedition was the equinoctial colure, did in the end of 1689 cut the ecliptic in 6° 29′ 15″. In the same manner our author determines that the mean place of the solstitial colure is 6° 28′ 46″, and as it is at right angles with the other, he concludes that it is rightly drawn. And hence he infers that the cardinal points, in the interval between that expedition and the year 1689, have receded from those colures 1s 6° 29′; which, allowing 72 years to a degree, amounts to 2627 years; and these counted backwards, as above, will place the Argonautic expedition 43 years after the death of Solomon. Our author has, by other methods also of a similar nature, established this epoch, and reduced the age of the world 500 years.
This elaborate system has not escaped censure; Mess. Freret and Souciet having both attacked it, and on much the same ground: but the sormer has confounded reigns and generations, which are carefully distinguished in this system. The aftronomical objections of both | have been answered by Sir Isaac Newton himself, and by Dr. Halley. Philos. Trans. abr. vol. 8, part 4, pa. 4. Newton's Chronol. ch. 1.
