In this chapter we shall, for the most part, be on firmer ground than hitherto, because several of the most eminent Greek and Latin historians have left on record full and circumstantial accounts of eclipses which have come under their notice, and which have been more or less completely verified by the computations and researches of astronomers in modern times. But these remarks do not, however, quite apply to the first eclipse which will be mentioned.
Plutarch, in his Life of Romulus, refers to some remarkable incident connected, in point of time at any rate, with his death:—“The air on that occasion was suddenly convulsed and altered in a wonderful manner, for the light of the Sun failed, and they were involved in an astonishing darkness, attended on every side with dreadful thunderings and tempestuous winds.” This so-called darkness is considered to have been the same as that mentioned by Cicero.[36] There is so much myth about Romulus that it is not safe to write in confident language. Nevertheless it is a fact, according to Johnson, that there was a very large eclipse of the Sun visible at Rome in the afternoon of May 26, 715 B.C., and 715 B.C. is supposed to have been the year, or about the year, of the death of Romulus. Plutarch is also responsible for the statement that a great eclipse of the Sun took place sometime before the birth of Romulus; and if there is anything in this statement Johnson thinks that the annular eclipse of November 28, 771 B.C., might meet the circumstances of the case, but too much romance attaches to the history of Romulus for anyone to write with assurance respecting the circumstances of his career. Much of it is generally considered to be fabulous.
In one of the extant fragments of the Greek poet Archilochus (said to be the first who introduced iambics into his verses), the following sentence occurs:—“Zeus the father of the Olympic Gods turned mid-day into night hiding the light of the dazzling sun; an overwhelming dread fell upon men.” The poet’s language may evidently apply to a total eclipse of the Sun; and investigations by Oppolzer and Millosevich make it probable that the reference is to the total eclipse of the Sun which happened on April 6, 648 B.C. This was total at about 10 a.m. at Thasos and in the northern part of the Ægean Sea. The acceptance of this date displaces by about half a century the date commonly assigned for the poet’s career, but this is not thought to be of much account having regard to the hazy character of Grecian chronology before the Persian wars.[37]
On May 28, 585 B.C. there occurred an eclipse the surrounding circumstances of which present several features of particular interest. One of the most celebrated of the astronomers of antiquity was Thales of Miletus, and his astronomical labours were said to have included a prediction of this eclipse, which moreover has the further interest to us that it has assisted chronologists and historians in fixing the precise date of an important event in ancient history. Herodotus[38] describing a war which had been going on for some years between the Lydians and the Medes gives the following account of the circumstances which led to its premature termination:—“As the balance had not inclined in favour of either nation, another engagement took place in the sixth year of the war, in the course of which, just as the battle was growing warm, day was suddenly turned into night. This event had been foretold to the Ionians by Thales of Miletus, who predicted for it the very year in which it actually took place. When the Lydians and Medes observed the change they ceased fighting, and were alike anxious to conclude peace.” Peace was accordingly agreed upon and cemented by a twofold marriage. “For (says the historian) without some strong bond, there is little security to be found in men’s covenants.” The exact date of this eclipse was long a matter of discussion, and eclipses which occurred in 610 B.C. and 593 B.C. were each thought at one time or another to have been the one referred to. The question was finally settled by the late Sir G.B. Airy, after an exhaustive inquiry, in favour of the eclipse of 585 B.C. This date has the further advantage of harmonising certain statements made by Cicero and Pliny as to its having happened in the 4th year of the 48th Olympiad.
Another word or two may be interesting as regards the share which Thales is supposed to have had in predicting this eclipse, the more so, that very high authorities in the domains of astronomy, and chronology, and antiquities take opposite sides in the matter. Sir G.C. Lewis, Bart., M.P., may be cited first as one of the unbelievers. He says[39] that Thales is “reported to have predicted it to the Ionians. If he had predicted it to the Lydians, in whose country the eclipse was to be total, his conduct would be intelligible, but it seems strange that he should have predicted it to the Ionians who had no direct interest in the event.” Bosanquet replies to this by pointing out that Miletus, in Ionia, was the birthplace of Thales, and also that a shadow, covering two degrees of latitude, passing through Ionia, would also necessarily cover Lydia.
Another dissentient is Sir H.C. Rawlinson,[40] who, remembering that Thales is said to have predicted a good olive crop, and Anaxagoras the fall of an aËrolite, says:—“The prediction of this eclipse by Thales may fairly be classed with the prediction of a good olive crop, or the fall of an aËrolite. Thales, indeed, could only have obtained the requisite knowledge for predicting eclipses from the Chaldeans; and that the science of these astronomers, although sufficient for the investigation of lunar eclipses, did not enable them to calculate solar eclipses—dependent as such a calculation is, not only on the determination of the period of recurrence, but on the true projection also of the track of the Sun’s shadow along a particular line over the surface of the earth—may be inferred from our finding that in the astronomical canon of Ptolemy, which was compiled from the Chaldean registers, the observations of the Moon’s eclipse are alone entered.”
Airy[41] replied to these observations as follows:—“I think it not at all improbable that the eclipse was so predicted, and there is one easy way, and only one of predicting it—namely, by the Saros, or period of 18 years, 10 days, 8 hours nearly. By use of this period an evening eclipse may be predicted from a morning eclipse but a morning eclipse can rarely be predicted from an evening eclipse (as the interval of eight hours after an evening eclipse will generally throw the eclipse at the end of the Saros into the hours of night). The evening eclipse, therefore, of B.C. 585, May 28, which I adopt as being most certainly the eclipse of Thales, might be predicted from the morning eclipse of B.C. 603, May 17.... No other of the eclipses discussed by Baily and Oltmanns present the same facility for prediction.”
Xenophon[42] mentions an eclipse as having led to the capture by the Persians of the Median city Larissa. In the retreat of the Greeks on the eastern side of the Tigris, they crossed the river Zapetes and also a ravine, and then reached the Tigris. According to Xenophon, they found at this place a large deserted city formerly inhabited by the Medes. Its wall was 25 feet thick and 100 feet high; its circumference 2 parasangs [=7½ miles]. It was built of burnt brick on an under structure of stone 20 feet in height. Xenophon then proceeds to say that “when the Persians obtained the Empire from the Medes, the King of the Persians besieged the city but was unable by any means to take it till a cloud having covered the Sun and caused it to disappear completely, the inhabitants withdrew in alarm, and thus the city was captured. Close to this city was a pyramid of stone, one plethrum in breadth, two plethra in height.... Thence the Greeks proceeded six parasangs to a great deserted castle by a city called Mespila formerly inhabited by the Medes; the substructure of its wall was of squared stone abounding in shells ... the King of the Persians besieged it but could not take it; Zeus terrified the inhabitants with thunderbolts, and so the city was taken.”
The minute description here given by Xenophon enabled Sir A.H. Layard, Captain Felix Jones, and others, to identify Larissa with the modern Nimrud and Mespila with Mosul. A suspicion is thrown out in some editions of the Anabasis that the language cited might refer to an eclipse of the Sun. It is to be noted, however, that it is not included by Ricciolus in the list of eclipses mentioned in ancient writers which he gives in his Almagestum Novum. Sir G.B. Airy, having had his attention called to the matter, examined roughly all the eclipses which occurred during a period of 40 years, covering the supposed date implied by Xenophon. Having selected two, he computed them accurately but found them inapplicable. He then tried another (May 19, 557 B.C.) which he had previously passed over because he doubted its totality, and he had the great satisfaction of finding that the eclipse, though giving a small shadow, had been total, and that it had passed so near to Nimrud that there could be no doubt of its being the eclipse sought.Sir G.B. Airy was such a very careful worker and investigator of eclipses that his conclusions in this matter have met with general acceptance. It must, however, in fairness be stated that a very competent American astronomer, Professor Newcomb, has expressed doubts as to whether after all Xenophon’s allusion is to an eclipse, but, judging by his closing words, the learned American does not seem quite satisfied with his own scepticism, for he says—“Notwithstanding my want of confidence, I conceive the possibility of a real eclipse to be greater than in the eclipse of Thales, while we have the great advantages that the point of occurrence is well defined, the shadow narrow, and, if it was an eclipse at all, the circumstance of totality placed beyond serious doubt.”[43]
In the same year as that in which, according to the common account, the battle of Salamis was fought (480 B.C.), there occurred a phenomenon which is thus adverted to by Herodotus[44]—“At the first approach of Spring the army quitted Sardis and marched towards Abydos; at the moment of its departure the Sun suddenly quitted its place in the heavens and disappeared though there were no clouds in sight and the day was quite clear; day was thus turned into night.” We are told[45] that “As the king was going against Greece, and had come into the region of the Hellespont, there happened an eclipse of the Sun in the East; this sign portended to him his defeat, for the Sun was eclipsed in the region of its rising, and Xerxes was also marching from that quarter.” So far as words go these accounts admirably befit a total eclipse of the Sun, but regarded as such it has given great trouble to chronologers, and the identification of the eclipse is still uncertain. Hind’s theory is that the allusion is to an eclipse and in particular to the eclipse of February 17, 478 B.C. Though not total at Sardis yet the eclipse was very large, 94/100ths of the Sun being covered. If we accept this, it follows that the usually recognised date for the battle of Salamis must be altered by two years. Airy thought it “extremely probable” that the narrative related to the total eclipse of the Moon, which happened on March 13, 479 B.C., but this is difficult to accept, especially as Plutarch, in his Life of Pelopidas, says—“An army was soon got ready, but as the general was on the point of marching, the Sun began to be eclipsed, and the city was covered with darkness in the daytime.” This seems explicit enough, assuming the record to be true and that the same incident is referred to by Plutarch as by Herodotus and Aristides.
Since the time when Airy and Hind examined this question, all the known facts have been again reviewed by Mr. W.T. Lynn, who pronounces, but with some hesitation, in favour of the eclipse of October 2, 480 B.C., as the one associated with the battle of Salamis. He does this by refusing to see in the above quotations from Herodotus any allusion to a solar eclipse at all, but invites us to consider a later statement in Herodotus[46] as relating to an eclipse though the historian only calls it a prodigy.
After the battle of ThermopylÆ the Peloponnesian Greeks commenced to fortify the isthmus of Corinth with the view of defending it with their small army against the invading host of Xerxes. The Spartan troops were under the command of Cleombrotus, the brother of Leonidas, the hero of ThermopylÆ. He had been consulting the oracles at Sparta, and Herodotus states that “while he was offering sacrifice to know if he should march out against the Persian, the Sun was suddenly darkened in mid-sky.” This occurrence so frightened Cleombrotus that he drew off his forces and returned home. It is uncertain from the narrative of Herodotus whether Cleombrotus returned to Sparta in the autumn of the year of the battle of Salamis, or in the spring of the next following year which was that in which the battle of PlatÆa was fought. Bishop Thirlwall[47] thinks that it was the latter, but Lynn pronounces for the former, adding that the date may well have been in October, and the solar eclipse of October 2, 480 B.C. may have been the phenomenon which attracted notice, particularly as the Sun would have been high in the heavens, the greatest phase (6/10ths) occurring, according to Hind, at 50 minutes past noon. Here I must leave the matter, merely remarking that this alternative explanation obviates the necessity for disturbing the commonly received date of the battle of Salamis.
Thucydides states that during the Peloponnesian war “things formerly repeated on hearsay, but very rarely confirmed by facts, became not incredible, both about earthquakes and eclipses of the Sun which came to pass more frequently than had been remembered in former times.” One such eclipse he assigns to the first year of the war and says[48] that “in the same summer, at the beginning of a new lunar month (at which time alone the phenomenon seems possible) the Sun was eclipsed after mid-day, and became full again after it had assumed a crescent form and after some of the stars had shone out.” Aug. 3, 431 B.C. is generally recognised as the date of this event. The eclipse was not total only three-fourths of the Sun’s disc being obscured. Venus was 20° and Jupiter 43° distant from the Sun, so probably these were the “stars” that were seen. This eclipse nearly prevented the Athenian expedition against the LacedÆmonians. The sailors were frightened by it, but a happy thought occurred to Pericles, the commander of the Athenian forces. Plutarch, in his Life of Pericles, says:—“The whole fleet was in readiness, and Pericles on board his own galley, when there happened an eclipse of the Sun. The sudden darkness was looked upon as an unfavourable omen, and threw the sailors into the greatest consternation. Pericles observing that the pilot was much astonished and perplexed, took his cloak, and having covered his eyes with it, asked him if he found anything terrible in that, or considered it as a bad presage? Upon his answering in the negative, he said, ‘Where is the difference, then between this and the other, except that something bigger than my cloak causes the eclipse?’”
Another eclipse is mentioned by Thucydides[49] in connection with an expedition of the Athenians against Cythera. He says:—“At the very commencement of the following summer there was an eclipse of the Sun at the time of a new moon, and in the early part of the same month an earthquake.” This has been identified with the annular eclipse of March 21, 424 B.C., the central line of which passed across Northern Europe. It is not quite clear whether the historian wishes to insinuate that the eclipse caused the earthquake or the earthquake the eclipse.
An eclipse known as that of Ennius is another of the eclipses antecedent to the Christian Era which has been the subject of full modern investigation, and the circumstances of which are such that, in the language of Professor Hansen, “it may be reckoned as one of the most certain and well-established eclipses of antiquity.” The record of it has only been brought to light in modern times by the discovery of Cicero’s Treatise, De RepublicÂ. According to Cicero,[50] Ennius the great Roman poet, who lived in the second century B.C., and who died of gout contracted, it is said, by frequent intoxication, recorded an interesting event in the following words:—Nonis Junii soli luna obstetit et nox, “On the Nones of June the Moon was in opposition to the Sun and night.” This singular phrase has long been assumed to allude to an eclipse of the Sun, but the precise interpretation of the words was not for a long time realised. In Cicero’s time the Nones of June fell on the 5th, but in the time of Ennius, who lived a century and a half before Cicero, the Nones of June fell between June 5 and July 4 on account of the lunar years and the intercalary month of the Roman Calendar. The date of this eclipse is distinctly known to be June 21, 400 B.C., but the hour was long in dispute. Professor Zech found that the Sun set at Rome eclipsed, and that the maximum phase took place after sun-set. Hansen, however, with his better Tables, found that the eclipse was total at Rome, and that the totality ended at 7.33 p.m., the Sun setting almost immediately afterwards at 7.36. This fact, Hansen considers, explains the otherwise unintelligible passage of Ennius quoted above: instead of saying et nox, he should have said et simul nox, “and immediately it was night.” Newcomb questions the totality of this eclipse, but assigns no clear reasons for his doubts.[51]
On August 14, 394 B.C., there was a large eclipse of the Sun visible in the Mediterranean. It occurred in the forenoon, and is mentioned by Xenophon[52] in connection with a naval engagement in which the Persians were defeated by Conon.Plutarch, in his Life of Pelopidas, relates how one, Alexander of PherÆ, had devastated several cities of Thessaly, and that as soon as the oppressed inhabitants had learned that Pelopidas had come back from an embassy on which he had been to the King of Persia, they sent deputies to him to Thebes to beg the favour of armed assistance, with Pelopidas as general. “The Thebans willingly granted their request, and an army was soon got ready, but as the general was on the point of marching, the Sun began to be eclipsed, and the city was covered with darkness in the day-time.” This eclipse is generally identified with that of July 13, 364 B.C. If this is correct, Plutarch’s language must be incorrect, or at least greatly exaggerated, for no more than about three-fourths of the Sun was obscured.
On February 29, 357 B.C., there happened an eclipse, also visible in or near the Mediterranean. This is supposed to have been the eclipse for the prediction of which Helicon, a friend of Plato, received from Dionysius, King of Syracuse, payment in the shape of a talent.
We have now to consider another ancient eclipse which has a history of peculiar interest as regards the investigations to which it has been subjected. It is commonly known as the “Eclipse of Agathocles,” and is recorded by two historians of antiquity in the words following. Diodorus Siculus[53] says:—
“Agathocles also, though closely pursued by the enemy, by the advantage of the night coming on (beyond all hope), got safe off from them. The next day there was such an eclipse of the Sun, that the stars appeared everywhere in the firmament, and the day was turned into night, upon which Agathocles’s soldiers (conceiving that God thereby did foretell their destruction) fell into great perplexities and discontents concerning what was like to befall them.”
Justin says[54]:—
“By the harangue the hearts of the soldiers were somewhat elevated, but an eclipse of the Sun that had happened during their voyage still possessed them with superstitious fears of a bad omen. The king was at no less pain to satisfy them about this affair than about the war, and therefore he told them that he should have thought this sign an ill presage for them, if it had happened before they set out, but having happened afterwards he could not but think it presaged ill to those against whom they marched. Besides, eclipses of the luminaries always signify a change of affairs, and therefore some change was certainly signified, either to Carthage, which was in such a flourishing condition, or to them whose affairs were in a very ruinous state.”
The substance of these statements is that in the year 310 B.C. Agathocles, Tyrant of Syracuse, while conducting his fleet from Syracuse to the Coast of Africa, found himself enveloped in the shadow of an eclipse, which evidently, from the accounts, was total. His fleet had been chased by the Carthaginians on leaving Syracuse the preceding day, but got away under the cover of night. On the following morning about 8 or 9 a.m. a sudden darkness came on which greatly alarmed the sailors. So considerable was the darkness, that numerous stars appeared. It is not at the first easy to localise the position of the fleet, except that we may infer that it could hardly have got more than 80 or at the most 100 miles away from the harbour of Syracuse where it had been closely blockaded by a Carthaginian fleet. Agathocles would not have got away at all but for the fact that a relieving fleet was expected, and the Carthaginians were obliged to relax their blockade in order to go in search of the relieving fleet. Thus it came about not only that Agathocles set himself free, but was able to retaliate on his enemies by landing on the coast of Africa at a point near the modern Cape Bon, and devastating the Carthaginian territories. The voyage thither occupied six days, and the eclipse occurred on the second day. Though we are not informed of the route followed by Agathocles, that is to say whether he passed round the North or the South side of the island of Sicily, yet it has been made clear by astronomers that the southern side was that taken.
Baily, who was the first modern astronomer to investigate the circumstances of this eclipse, found that there was an irreconcilable difference between the path of the shadow found by himself and the historical statement, a gap of about 180 geographical miles seeming to intervene between the most southerly position which could be assigned to the fleet of Agathocles, and the most northerly possible limit of the path of the eclipse shadow. This was the condition of the problem when Sir G.B. Airy took it up in 1853.[55] He, however, was able to throw an entirely new light upon the matter. The tables used by Baily were distinctly inferior to those now in use, and Sir G.B. Airy thought himself justified in saying that to obviate the discordance of 180 miles just referred to “it is only necessary to suppose an error of 3' in the computed distances of the Sun and Moon at conjunction, a very inconsiderable correction for a date anterior to the epoch of the tables by more than twenty-one centuries.”
It deserves to be mentioned, though the point cannot here be dwelt upon at much length, that these ancient eclipses all hang together in such a way that it is not sufficient for the man of Astronomy and the man of Chronology to agree on one eclipse, unless they can harmonise the facts of several.
For instance, the eclipse of Thales, the date of which was long and much disputed, has a material bearing on the eclipse of Agathocles, the date of which admits of no dispute; and one of the problems which had to be solved half a century ago was how best to use the eclipse of Agathocles to determine the date of that of Thales. If 610 B.C. were accepted for the Thales eclipse, so as to throw the zone of total darkness anywhere over Asia Minor (where for the sake of history it was essential to put it) the consequence would be that the shadow of the eclipse of 310 B.C. would have been thrown so far on to land, in Africa, as to make it out of the question for Agathocles and his fleet to have been in it, yet we know for a certainty that he was in it in that year, and no other year. Conversely, if 603 B.C. were accepted for the Thales eclipse, then to raise northwards the position of the shadow in that year from the line of the Red Sea and the Persian Gulf, that it might pass through Asia Minor, would so raise the position of the shadow in 310 B.C. as to throw it far too much to the N. of Sicily for Agathocles, who we know must have gone southwards to Africa, to have entered it. But if we assume 585 B.C. as the date of the eclipse of Thales, we obtain a perfect reconciliation of everything that needs to be reconciled; the shadow of the eclipse of 585 B.C. will be found to have passed where ancient history tells us it did pass—namely, through Ionia, and therefore through the centre of Asia Minor, and on the direct route from Lydia to Media; whilst we also find that the shadow of the 310 B.C. eclipse, that is the one in the time of Agathocles, passed within 100 miles of Syracuse, a fact which is stated almost in those very words by the two historians who have recorded the doings of Agathocles and his fleet in those years.
This is where the matter was left by Airy in 1853. Four years later the new solar and lunar tables of the German astronomer Hansen were published, and having been applied to the eclipse of 585 B.C., the conclusions just stated were amply confirmed. As if to make assurance doubly sure, Airy went over his ground again, testing his former conclusions with regard to the eclipse of Thales by the eclipse of Larissa, in 557 B.C. already referred to, and bringing in the eclipse of Stiklastad in 1030 A.D., to be referred to presently. And as the final result, it may be stated that all the foregoing dates are now known to an absolute certainty, especially confirmed as they were in all essential points by a computer of the eminence of the late Mr. J.R. Hind.
On a date which corresponds to February 11, 218 or 217 B.C., an eclipse of the Sun, which was partial in Italy, is mentioned by Livy.[56] Newcomb found that the central line passed a long way from Italy, to wit, “far down in Africa.”
An eclipse of the Sun is mentioned by Dion Cassius[57] as having happened when CÆsar crossed the Rubicon, a celebrated event made use of by speakers, political and otherwise, on endless occasions in modern history. There seems no doubt that the passage of the Rubicon took place in 51 B.C., and that the eclipse must have been that of March 7, 51 B.C. The circumstances of this eclipse have been investigated by Hind, who found that the eclipse was an annular one, the annular phase lasting 6½ minutes in Northern Italy.
Arago associates the death of Julius CÆsar in 44 B.C. with an annular eclipse of the Sun, but seemingly without sufficient warrant. The actual record is to the effect that about the time of the great warrior’s death there was an extraordinary dimness of the Sun. Whatever it was that was noticed, clearly it could not have been an annular eclipse, because no such eclipse then happened. Johnson suggests that Arago confused the record of some meteorological interference with the Sun’s light with the annular eclipse that happened seven years previously when CÆsar passed the Rubicon, to which eclipse allusion has already been made. That there was for a long while a great deficiency of sunshine in Italy about the time of CÆsar’s death seems clear from remarks made by Pliny, Plutarch, and Tibullus, and the words of Suetonius seem to imply something of a meteorological character. I should not have mentioned this matter at all, but for Arago’s high repute as an astronomer. According to Seneca[58] during an eclipse a comet was also seen.
It is an interesting question to inquire whether any allusions to eclipses are to be found in Homer, and no very certain answer can be given. In the Iliad (book xvii., lines 366-8) the following passage will be found:—“Nor would you say that the Sun was safe, or the Moon, for they were wrapt in dark haze in the course of the combat.”
In the Odyssey (book xx., lines 356-7) we find:—“And the Sun has utterly perished from heaven and an evil gloom is overspread.” This was considered by old commentators to be an allusion to an eclipse, and in the opinion of W.W. Merry[59] “this is not impossible, as they were celebrating the Festival of the New Moon.”
Certainly this language has somewhat the savour of a total eclipse of the Sun, but it is difficult to say whether the allusion is historic, as of a fact that had happened, or only a vague generality. Perhaps the latter is the most justifiable surmise.
I have in the many preceding pages been citing ancient eclipses, for the reason, more or less plainly expressed, that they are of value to astronomers as assisting to define the theory of the Moon’s motions in its orbit, and this they should do; but it is not unreasonable to bring this chapter to a close by giving the views of an eminent American astronomer as to the objections to placing too much reliance on ancient accounts of eclipses. Says Prof. S. Newcomb[60]:—“The first difficulty is to be reasonably sure that a total eclipse was really the phenomenon observed. Many of the statements supposed to refer to total eclipses are so vague that they may be referred to other less rare phenomena. It must never be forgotten that we are dealing with an age when accurate observations and descriptions of natural phenomena were unknown, and when mankind was subject to be imposed upon by imaginary wonders and prodigies. The circumstance which we should regard as most unequivocally marking a total eclipse is the visibility of the stars during the darkness. But even this can scarcely be regarded as conclusive, because Venus may be seen when there is no eclipse, and may be quite conspicuous in an annular or a considerable partial eclipse. The exaggeration of a single object into a plural is in general very easy. Another difficulty is to be sure of the locality where the eclipse was total. It is commonly assumed that the description necessarily refers to something seen where the writer flourished, or where he locates his story. It seems to me that this cannot be safely done unless the statement is made in connection with some battle or military movement, in which case we may presume the phenomena to have been seen by the army.”
