I have hitherto only considered the appearance of the dusky ring as seen on either side of the planet's globe within the bright rings. The most remarkable feature of the appendage remains still to be mentioned—the fact, namely, that the bright body of the planet can be seen through this dusky ring. Where the dark ring crosses the planet, it appears as a rather dark belt, which might readily be mistaken for a belt upon the planet's surface; for the outline of the planet can be seen through the ring as through a film of smoke or a crape veil.

Now it is worthy of notice that whereas the dark ring was not detected outside the planet's body until 1838, nor generally recognised by astronomers until 1850, the dark belt across the planet, really caused by the dusky ring, was observed more than a century earlier. In 1715 the younger Cassini saw it, and perceived that it was not curved enough for a belt really belonging to the planet. Hadley again observed that the belt attended the ring as this opened out and closed, or, in other words, that the dark belt belonged to the ring, not to the body of the planet. And in many pictures of Saturn's system a dark band is shown along the inner edge of the inner bright ring where it crosses the body of the planet. It seems to me that we have here a most important piece of evidence respecting the rings. It is clear that the inner part of the inner bright ring has for more than a century and a half (how much more we do not know) been partially transparent, and it is probable that within its inner edge there has been all the time a ring of matter; but this ring has only within the last half-century gathered consistency enough to be discernible. It is manifest that the existence of the dark belt shown in the older pictures would have led directly to the detection of the dark ring, had not this appendage been exceedingly faint. Thus, while the observation of the dark belt across the planet's face proves the dusky ring to have existed in some form long before it was perceived, the same fact only helps to render us certain that the dark ring has changed notably in condition during the present century.

The discovery of this singular appendage, an object unique in the solar system, naturally attracted fresh attention to the question of the stability of the rings. The idea was thrown out by the elder Bond that the new ring may be fluid, or even that the whole ring-system may be fluid, and the dark ring simply thinner than the rest. It was thought possible that the ring-system is of the nature of a vast ocean, whose waves are steadily advancing upon the planet's globe. The mathematical investigation of the subject was also resumed by Professor Benjamin Pierce, of Harvard, and it was satisfactorily demonstrated that the stability of a system of actual rings of solid matter required so nice an adjustment of so many narrow rings as to render the system far more complex than even Laplace had supposed. 'A stable formation can,' he said, 'be nothing other than a very great number of separate narrow rigid rings, each revolving with its proper relative velocity.' As was well remarked by the late Professor Nichol, 'If this arrangement or anything like it were real, how many new conditions of instability do we introduce. Observation tells us that the division between such rings must be extremely narrow, so that the slightest disturbance by external or internal causes would cause one ring to impinge upon another; and we should thus have the seed of perpetual catastrophes.' Nor would such a constitution protect the system against dissolution. 'There is no escape from the difficulties, therefore, but through the final rejection of the idea that Saturn's rings are rigid or in any sense a solid formation.'

The idea that the ring-system may be fluid came naturally next under mathematical scrutiny. Strangely enough, the physical objections to the theory of fluidity appear to have been entirely overlooked. Before we could accept such a theory, we must admit the existence of elements differing entirely from those with which we are familiar. No fluid known to us could retain the form of the rings of Saturn under the conditions to which they are exposed. But the mathematical examination of the subject disposed so thoroughly of the theory that the rings can consist of continuous fluid masses, that we need not now discuss the physical objections to the theory.

There remains only the theory that the Saturnian ring-system consists of discrete masses analogous to the streams of meteors known to exist in great numbers within the solar system. The masses may be solid or fluid, may be strewn in relatively vacant space, or may be surrounded by vaporous envelopes; but that they are discrete, each free to travel on its own course, seemed as completely demonstrated by Pierce's calculations as anything not actually admitting of direct observation could possibly be. The matter was placed beyond dispute by the independent analysis to which Clerk Maxwell subjected the mathematical problem. It had been selected in 1855 as the subject for the Adams Prize Essay at Cambridge, and Clerk Maxwell's essay, which obtained the prize, showed conclusively that only a system of many small bodies, each free to travel upon its course under the varying attractions to which it was subjected by Saturn itself, and by the Saturnian satellites, could possibly continue to girdle a planet as the rings of Saturn girdle him.

It is clear that all the peculiarities hitherto observed in the Saturnian ring-system are explicable so soon as we regard that system as made up of multitudes of small bodies. Varieties of brightness simply indicate various degrees of condensation of these small satellites. Thus the outer ring had long been observed to be less bright than the inner. Of course it did not seem impossible that the outer ring might be made of different materials; yet there was something bizarre in the supposition that two rings forming the same system were thus different in substance. It would not have been at all noteworthy if different parts of the same ring differed in luminosity—in fact, it was much more remarkable that each zone of the system seemed uniformly bright all round. But that one zone should be of one tint, another of an entirely different tint, was a strange circumstance so long as the only available interpretation seemed to be that one zone was made (throughout) of one substance, the other of another. If this was strange when the difference between the inner and outer bright rings was alone considered, how much stranger did it seem when the multitudinous divisions in the rings were taken into account! Why should the ring-system, 30,000 miles in width, be thus divided into zones of different material? An arrangement so artificial is quite unlike all that is elsewhere seen among the subjects of the astronomer's researches. But when the rings are regarded as made up of multitudes of small bodies, we can quite readily understand how the nearly circular movements of all of these, at different rates, should result in the formation of rings of aggregation and rings of segregation, appearing at the earth's distance as bright rings and faint rings. The dark ring clearly corresponds in appearance with a ring of thinly scattered satellites. Indeed, it seems impossible otherwise to account for the appearance of a dusky belt across the globe of the planet where the dark ring crosses the disc. If the material of the dark ring were some partly transparent solid or fluid substance, the light of the planet received through the dark ring added to the light reflected by the dark ring itself, would be so nearly equivalent to the light received from the rest of the planet's disc, that either no dark belt would be seen, or the darkening would be barely discernible. In some positions a bright belt would be seen, not a dark one. But a ring of scattered satellites would cast as its shadow a multitude of black spots, which would give to the belt in shadow a dark grey aspect. A considerable proportion of these spots would be hidden by the satellites forming the dark ring, and in every case where a spot was wholly or partially hidden by a satellite, the effect (at our distant station where the separate satellites of the dark ring are not discernible) would simply be to reduce pro tanto the darkness of the grey belt of shadow. But certainly more than half the shadows of the satellites would remain in sight; for the darkness of the ring at the time of its discovery showed that the satellites were very sparsely strewn. And these shadows would be sufficient to give to the belt a dusky hue, such as it presented when first discovered.[37]

The observations which have recently been made by Mr. Trouvelot indicate changes in the ring-system, and especially in the dark ring, which place every other theory save that to which we have thus been led entirely out of the question. It should be noted that Mr. Trouvelot has employed telescopes of unquestionable excellence and varying in aperture from six inches to twenty-six inches, the latter aperture being that of the great telescope of the Washington Observatory (the largest refractor in the world).

He has noted in the first place that the interior edge of the outer bright ring, which marks the outer limit of the great division, is irregular, but whether the irregularity is permanent or not he does not know. The great division itself is found not to be actually black, but, as was long since noted by Captain Jacob, of the Madras Observatory, a very dark brown, as though a few scattered satellites travelled along this relatively vacant zone of the system. Mr. Trouvelot has further noticed that the shadow of the planet upon the rings, and especially upon the outer ring, changes continually in shape, a circumstance which he attributes to irregularities in the surface of the rings. For my own part, I should be disposed to attribute these changes in the shape of the planet's shadow (noted by other observers also) to rapid changes in the deep cloud-laden atmosphere of the planet. Passing on, however, to less doubtful observations, we find that the whole system of rings has presented a clouded and spotted aspect during the last four years. Mr. Trouvelot specially describes this appearance as observed on the parts of the ring outside the disc, called by astronomers the ansae (because of their resemblance to handles), and it would seem, therefore, that the spotted and cloudy portions are seen only where the background on which the rings are projected is black. This circumstance clearly suggests that the darkness of these parts is due to the background, or, in other words, that the sky is in reality seen through those parts of the ring-system, just as the darkness of the slate-coloured interior ring is attributed, on the satellite theory, to the background of sky visible through the scattered flight of satellites forming the dark ring. The matter composing the dark ring has been observed by Mr. Trouvelot to be gathered in places into compact masses, which prevent the light of the planet from being seen through those portions of the dark ring where the matter is thus massed together. It is clear that such peculiarities could not possibly present themselves in the case of a continuous solid or fluid ring-system, whereas they would naturally occur in a ring formed of multitudes of minute bodies travelling freely around the planet.

The point next to be mentioned is still more decisive. When the dark ring was carefully examined with powerful telescopes during the ten years following its discovery by Bond, at which time it was most favourably placed for observation, it was observed that the outline of the planet could be seen across the entire breadth of the dark ring. All the observations agreed in this respect. It was, indeed, noticed by Dawes that outside the planet's disc the dark ring showed varieties of tint, its inner half being darker than its outer portion. Lassell, observing the planet under most favourable conditions with his two-feet mirror at Malta, could not perceive these varieties of tint, which therefore we may judge to have been either not permanent or very slightly marked. But, as I have said, all observers agreed that the outline of the planet could be seen athwart the entire width of the dark ring. Mr. Trouvelot, however, has found that during the last four years the planet has not been visible through the whole width of the dark ring, but only through the inner half of the ring's breadth. It appears, then, that either the inner portion is getting continually thinner and thinner—that is, the satellites composing it are becoming continually more sparsely strewn—or that the outer portion is becoming more compact, doubtless by receiving stray satellites from the interior of the inner bright ring.

It is clear that in Saturn's ring-system, if not in the planet itself, mighty changes are still taking place. It may be that the rings are being so fashioned under the forces to which they are subjected as to be on their way to becoming changed into separate satellites, inner members of that system which at present consists of eight secondary planets. But, whatever may be the end towards which these changes are tending, we see processes of evolution taking place which may be regarded as typifying the more extensive and probably more energetic processes whereby the solar system itself reached its present condition. I ventured more than ten years ago, in the preface to my treatise upon the planet Saturn, to suggest the possibility 'that in the variations perceptibly proceeding in the Saturnian ring-system a key may one day be found to the law of development under which the solar system has reached its present condition.' This suggestion seems to me strikingly confirmed by the recent discoveries. The planet Saturn and its appendages, always interesting to astronomers, are found more than ever worthy of close investigation and scrutiny. We may here, as it were, seize nature in the act, and trace out the actual progress of developments which at present are matters rather of theory than of observation.



VIII.

COMETS AS PORTENTS

The blazing star, Threat'ning the world with famine, plague, and war; To princes death; to kingdoms many curses; To all estates inevitable losses; To herdsmen rot; to ploughmen hapless seasons; To sailors storms; to cities civil treasons.

Although comets are no longer regarded with superstitious awe as in old times, mystery still clings to them. Astronomers can tell what path a comet is travelling upon, and say whence it has come and whither it will go, can even in many cases predict the periodic returns of a comet, can analyse the substance of these strange wanderers, and have recently discovered a singular bond of relationship between comets and those other strange visitants from the celestial depths, the shooting stars. But astronomy has hitherto proved unable to determine the origin of comets, the part they perform in the economy of the universe, their real structure, the causes of the marvellous changes of shape which they undergo as they approach the sun, rush round him, and then retreat. As Sir John Herschel has remarked: 'No one, hitherto, has been able to assign any single point in which we should be a bit better or worse off, materially speaking, if there were no such thing as a comet. Persons, even thinking persons, have busied themselves with conjectures; such as that they may serve for fuel for the sun (into which, however, they never fall), or that they may cause warm summers, which is a mere fancy, or that they may give rise to epidemics, or potato-blights, and so forth.' And though, as he justly says, 'this is all wild talking,' yet it will probably continue until astronomers have been able to master the problems respecting comets which hitherto have foiled their best efforts. The unexplained has ever been and will ever be marvellous to the general mind. Just as unexplored regions of the earth have been tenanted in imagination by

anthropophagi and men whose heads Do grow beneath their shoulders,

so do wondrous possibilities exist in the unknown and the ill-understood phenomena of nature.

In old times, when the appearance and movements of comets were supposed to be altogether uncontrolled by physical laws, it was natural that comets should be regarded as signs from heaven, tokens of Divine wrath towards some, and of the interposition of Divine providence in favour of others. As Seneca well remarked: 'There is no man so dull, so obtuse, so turned to earthly things, who does not direct all the powers of his mind towards things Divine when some novel phenomenon appears in the heavens. While all follows its usual course up yonder, familiarity robs the spectacle of its grandeur. For so is man made. However wonderful may be what he sees day after day, he looks on it with indifference; while matters of very little importance attract and interest him if they depart from the accustomed order. The host of heavenly constellations beneath the vault of heaven, whose beauty they adorn, attract no attention; but if any unusual appearance be noticed among them, at once all eyes are turned heavenwards. The sun is only looked on with interest when he is undergoing eclipse. Men observe the moon only under like conditions.... So thoroughly is it a part of our nature to admire the new rather than the great. The same is true of comets. When one of these fiery bodies of unusual form appears, every one is eager to know what it means; men forget other objects to inquire about the new arrival; they know not whether to wonder or to tremble; for many spread fear on all sides, drawing from the phenomenon most grave prognostics.'

There is no direct reference to comets in the Bible, either in the Old Testament or the New. It is possible that some of the signs from heaven recorded in the Bible pages were either comets or meteors, and that even where in some places an angel or messenger from God is said to have appeared and delivered a message, what really happened was that some remarkable phenomenon in the heavens was interpreted in a particular manner by the priests, and the interpretation afterwards described as the message of an angel. The image of the 'flaming sword which turned every way' may have been derived from a comet; but we can form no safe conclusion about this, any more than we can upon the question whether the 'horror of great darkness' which fell upon Abraham (Genesis xv. 12) when the sun was going down, was caused by an eclipse;[38] or whether the going back of the shadow upon the dial of Ahaz was caused by a mock sun. The star seen by the wise men from the east may have been a comet, since the word translated 'star' signifies any bright object seen in the heavens, and is in fact the same word which Homer, in a passage frequently referred to, uses to signify either a comet or a meteor. The way in which it appeared to go before them, when (directed by Herod, be it noticed) they went to Bethlehem, almost due south of Jerusalem, would correspond to a meridian culmination low down—for the star had manifestly not been visible in the earlier evening, since we are told that they rejoiced when they saw the star again. It was probably a comet travelling southwards; and, as the wise men had travelled from the east, it had very likely been first seen in the west as an evening star, wherefore its course was retrograde—that is, supposing it was a comet.[39] It may possibly have been an apparition of Halley's comet, following a course somewhat similar to that which it followed in the year 1835, when the perihelion passage was made on November 15, and the comet running southwards disappeared from northern astronomers, though in January it was 'received' by Sir J. Herschel, to use his own expression, 'in the southern hemisphere.' There was an apparition of Halley's comet in the year 66, or seventy years after the Nativity; and the period of the comet varies, according to the perturbing influences affecting the comet's motion, from sixty-nine to eighty years.

Homer does not, to the best of my recollection, refer anywhere directly to comets. Pope, indeed, who made very free with Homer's references to the heavenly bodies,[40] introduces a comet—and a red one, too!—into the simile of the heavenly portent in Book IV.:—

As the red comet from Saturnius sent To fright the nations with a dire portent (A fatal sign to armies in the plain, Or trembling sailors on the wintry main), With sweeping glories glides along in air, And shakes the sparkles from its blazing hair: Between two armies thus, in open sight, Shot the bright goddess in a trail of light.

But Homer says nothing of this comet. If Homer had introduced a comet, we may be sure it would not have shaken sparkles from its blazing tail. Homer said simply that 'Pallas rushed from the peaks of heaven, like the bright star sent by the son of crafty-counselled Kronus (as a sign either to sailors, or the broad array of the nations), from which many sparks proceed.' Strangely enough, Pingre and Lalande, the former noted for his researches into ancient comets, the latter a skilful astronomer, agree in considering that Homer really referred to a comet, and they even regard this comet as an apparition of the comet of 1680. They cite in support of this opinion the portent which followed the prayer of Anchises, 'AEneid,' Book II. 692, etc.: 'Scarce had the old man ceased from praying, when a peal of thunder was heard on the left, and a star, gliding from the heavens amid the darkness, rushed through space followed by a long train of light; we saw the star,' says AEneas, 'suspended for a moment above the roof, brighten our home with its fires, then, tracing out a brilliant course, disappear in the forests of Ida; then a long train of flame illuminated us, and the place around reeked with the smell of sulphur. Overcome by these startling portents, my father arose, invoked the gods, and worshipped the holy star.' It is impossible to recognise here the description of a comet. The noise, the trail of light, the visible motion, the smell of sulphur, all correspond with the fall of a meteorite close by; and doubtless Virgil simply introduced into the narrative the circumstances of some such phenomenon which had been witnessed in his own time. To base on such a point the theory that the comet of 1680 was visible at the time of the fall of Troy, the date of which is unknown, is venturesome in the extreme. True, the period calculated for the comet of 1680, when Pingre and Lalande agreed in this unhappy guess, was 575 years; and if we multiply this period by five we obtain 2875 years, taking 1680 from which leaves 1195 years B.C., near enough to the supposed date of the capture of Troy. Unfortunately, Encke (the eminent astronomer to whom we owe that determination of the sun's distance which for nearly half a century held its place in our books, but has within the last twenty years been replaced by a distance three millions of miles less) went over afresh the calculations of the motions of that famous comet, and found that, instead of 575 years, the most probable period is about 8814 years. The difference amounts only to 8239 years; but even this small difference rather impairs the theory of Lalande and Pingre.[41]

Three hundred and seventy-one years before the Christian era, a comet appeared which Aristotle (who was a boy at the time) has described. Diodorus Siculus writes thus respecting it: 'In the first year of the 102d Olympiad, Alcisthenes being Archon of Athens, several prodigies announced the approaching humiliation of the Lacedaemonians; a blazing torch of extraordinary size, which was compared to a flaming beam, was seen during several nights.' Guillemin, from whose interesting work on Comets I have translated the above passage, remarks that this same comet was regarded by the ancients as having not merely presaged but produced the earthquakes which caused the towns of Helice and Bura to be submerged. This was clearly in the thoughts of Seneca when he said of this comet that as soon as it appeared it brought about the submergence of Bura and Helice.

In those times, however, comets were not regarded solely as signs of disaster. As the misfortunes of one nation were commonly held to be of advantage to other nations, so the same comet might be regarded very differently by different nations or different rulers. Thus the comet of the year 344 B.C. was regarded by Timoleon of Corinth as presaging the success of his expedition against Corinth. 'The gods announced,' said Diodorus Siculus, 'by a remarkable portent, his success and future greatness; a blazing torch appeared in the heavens at night, and went before the fleet of Timoleon until he arrived in Sicily.' The comets of the years 134 B.C. and 118 B.C. were not regarded as portents of death, but as signalising, the former the birth, the latter the accession, of Mithridates. The comet of 43 B.C. was held by some to be the soul of Julius Caesar on its way to the abode of the gods. Bodin, a French lawyer of the sixteenth century, regarded this as the usual significance of comets. He was, indeed, sufficiently modest to attribute the opinion to Democritus, but the whole credit of the discovery belonged to himself. He maintained that comets only indicate approaching misfortunes because they are the spirits or souls of illustrious men, who for many years have acted the part of guardian angels, and, being at last ready to die, celebrate their last triumph by voyaging to the firmament as flaming stars. 'Naturally,' he says, 'the appearance of a comet is followed by plague, pestilence, and civil war; for the nations are deprived of the guidance of their worthy rulers, who, while they were alive, gave all their efforts to prevent intestine disorders.' Pingre comments justly on this, saying that 'it must be classed among base and shameful flatteries, not among philosophic opinions.'

Usually, however, it must be admitted that the ancients, like the men of the Middle Ages, regarded comets as harbingers of evil. 'A fearful star is the comet,' says Pliny, 'and not easily appeased, as appeared in the late civil troubles when Octavius was consul; a second time by the intestine war of Pompey and Caesar; and, in our own time, when, Claudius Caesar having been poisoned, the empire was left to Domitian, in whose reign there appeared a blazing comet.' Lucan tells us of the second event here referred to, that during the war 'the darkest nights were lit up by unknown stars' (a rather singular way of saying that there were no dark nights); 'the heavens appeared on fire, flaming torches traversed in all directions the depths of space; a comet, that fearful star which overthrows the powers of the earth, showed its horrid hair.' Seneca also expressed the opinion that some comets portend mischief: 'Some comets,' he said, 'are very cruel and portend the worst misfortunes; they bring with them and leave behind them the seeds of blood and slaughter.'

It was held, indeed, by many in those times a subject for reproach that some were too hard of heart to believe when these signs were sent. It was a point of religious faith that 'God worketh' these 'signs and wonders in heaven.' When troubles were about to befall men, 'nation rising against nation, and kingdom against kingdom, with great earthquakes in divers places, and famines, and pestilences, and fearful sights,' then 'great signs shall there be from heaven.' Says Josephus, commenting on the obstinacy of the Jews in such matters, 'when they were at any time premonished from the lips of truth itself, by prodigies and other premonitory signs of their approaching ruin, they had neither eyes nor ears nor understanding to make a right use of them, but passed them over without heeding or so much as thinking of them; as, for example, what shall we say of the comet in the form of a sword that hung over Jerusalem for a whole year together?' This was probably the comet described by Dion Cassius (Hist. Roman. lxv. 8) as having been visible between the months of April and December in the year 69 A.D. This or the comet of 66 A.D. might have been Halley's comet. The account of Josephus as to the time during which it was visible would not apply to Halley's, or, indeed, to any known comet whatever; doubtless he exaggerated. He says: 'The comet was of the kind called Xiphias, because their tail resembles the blade of a sword,' and this would apply fairly well to Halley's comet as seen in 1682, 1759, and 1835; though it is to be remembered that comets vary very much even at successive apparitions, and it would be quite unsafe to judge from the appearance of a comet seen eighteen centuries ago that it either was or was not the same as some comet now known to be periodic.

The comet of 79 A.D. is interesting as having given rise to a happy retort from Vespasian, whose death the comet was held to portend. Seeing some of his courtiers whispering about the comet, 'That hairy star,' he said, 'does not portend evil to me. It menaces rather the king of the Parthians. He is a hairy man, but I am bald.'

Anna Comnena goes even beyond Josephus. He only rebuked other men for not believing so strongly as he did himself in the significance of comets—a rebuke little needed, indeed, if we can judge from what history tells us of the terrors excited by comets. But the judicious daughter of Alexius was good enough to approve of the wisdom which provided these portents. Speaking of a remarkable comet which appeared before the irruption of the Gauls into the Roman empire, she says: 'This happened by the usual administration of Providence in such cases; for it is not fit that so great and strange an alteration of things as was brought to pass by that irruption of theirs should be without some previous denunciation and admonishment from heaven.'

Socrates, the historian (b. 6, c. 6), says that when Gainas besieged Constantinople, 'so great was the danger which hung over the city, that it was presignified and portended by a huge blazing comet which reached from heaven to the earth, the like whereof no man had ever seen before.' And Cedrenus, in his 'Compendium of History,' states that a comet appeared before the death of Johannes Tzimicas, the emperor of the East, which foreshadowed not alone his death, but the great calamities which were to befall the Roman empire by reason of their civil wars. In like manner, the comet of 451 announced the death of Attila, that of 455 the death of Valentinian. The death of Merovingius was announced by the comet of 577, of Chilperic by that of 584, of the Emperor Maurice by that of 602, of Mahomet by that of 632, of Louis the Debonair by that of 837, and of the Emperor Louis II. by that of 875. Nay, so confidently did men believe that comets indicated the approaching death of great men, that they did not believe a very great man could die without a comet. So they inferred that the death of a very great man indicated the arrival of a comet; and if the comet chanced not to be visible, so much the worse—not for the theory, but—for the comet. 'A comet of this kind,' says Pingre, 'was that of the year 814, presaging the death of Charlemagne.' So Guillemin quotes Pingre; but he should rather have said, such was the comet whose arrival was announced by Charlemagne's death—and in no other way, for it was not seen by mortal man.

The reader who chances to be strong as to his dates may have observed that some of the dates above mentioned for comets do not accord exactly with the dates of the events associated with those comets. Thus Louis the Debonair did not die in 837, but in 840. This, however, is a matter of very little importance. If some men, after their comet has called for them, are 'an unconscionable time in dying,' as Charles II. said of himself, it surely must not be considered the fault of the comet. Louis himself regarded the comet of 837 as his death-warrant; the astrologers admitted as much: what more could be desired? The account of the matter given in a chronicle of the time, by a writer who called himself 'The Astronomer,' is curious enough: 'During the holy season of Easter, a phenomenon, ever fatal and of gloomy foreboding, appeared in the heavens. As soon as the emperor, who paid attention to such phenomena, received the first announcement of it, he gave himself no rest until he had called a certain learned man and myself before him. As soon as I arrived, he anxiously asked me what I thought of such a sign. I asked time of him, in order to consider the aspect of the stars, and to discover the truth by their means, promising to acquaint him on the morrow; but the emperor, persuaded that I wished to gain time, which was true, in order not to be obliged to announce anything fatal to him, said to me: "Go on the terrace of the palace, and return at once to tell me what you have seen, for I did not see this star last evening, and you did not point it out to me; but I know that it is a comet; tell me what you think it announces to me." Then, scarcely allowing me time to say a word, he added: "There is still another thing you keep back: it is that a change of reign and the death of a prince are announced by this sign." And as I advanced the testimony of the prophet, who said: "Fear not the signs of the heavens as the nations fear them," the prince, with his grand nature and the wisdom which never forsook him, said: "We must only fear Him who has created both us and this star. But, as this phenomenon may refer to us, let us acknowledge it as a warning from heaven."' Accordingly, Louis himself and all his court fasted and prayed, and he built churches and monasteries. But all was of no avail. In little more than three years he died; showing, as the historian Raoul Glaber remarked, that 'these phenomena of the universe are never presented to man without surely announcing some wonderful and terrible event.' With a range of three years in advance, and so many kings and princes as there were about in those days, and are still, it would be rather difficult for a comet to appear without announcing some such wonderful and terrible event as a royal death.

The year 1000 A.D. was by all but common consent regarded as the date assigned for the end of the world. For a thousand years Satan had been chained, and now he was to be loosened for a while. So that when a comet made its appearance, and, terrible to relate, continued visible for nine days, the phenomenon was regarded as something more than a nine days' wonder. Besides the comet, a very wonderful meteor was seen. 'The heavens opened, and a kind of flaming torch fell upon the earth, leaving behind a long track of light like the path of a flash of lightning. Its brightness was so great that it frightened not only those who were in the fields, but even those who were in their houses. As this opening in the sky slowly closed men saw with horror the figure of a dragon, whose feet were blue, and whose head' [like that of Dickens's dwarf] 'seemed to grow larger and larger.' A picture of this dreadful meteor accompanies the account given by the old chronicler. For fear the exact likeness of the dragon might not be recognised (and, indeed, to see it one must 'make believe a good deal'), there is placed beside it a picture of a dragon to correspond, which picture is in turn labelled 'Serpens cum ceruleis pedibus.' It was considered very wicked in the year 1000 to doubt that the end of all things was at hand. But somehow the world escaped that time.

In the year 1066 Halley's comet appeared to announce to the Saxons the approaching conquest of England by William the Norman. A contemporary poet made a singular remark, which may have some profound poetical meaning, but certainly seems a little indistinct on the surface. He said that 'the comet had been more favourable to William than nature had been to Caesar; the latter had no hair, but William had received some from the comet.' This is the only instance, so far as I know, in which a comet has been regarded as a perruquier. A monk of Malmesbury spoke more to the purpose, according to then received ideas, in thus apostrophising the comet: 'Here art thou again, cause of tears to many mothers! It is long since I saw thee last, but I see thee now more terrible than ever; thou threatenest my country with complete ruin.'

Halley's comet, with its inconveniently short period of about seventy-seven years, has repeatedly troubled the nations and been regarded as a sign sent from Heaven:

Ten million cubic miles of head, Ten billion leagues of tail,

all provided for the sole purpose of warning one petty race of earth-folks against the evils likely to be brought against them by another. This comet has appeared twenty-four times since the date of its first recorded appearance, which some consider to have been 12 B.C., and others refer to a few years later. It may be interesting to quote here Babinet's description of the effects ascribed in 1455 to this comet, often the terror of nations, but the triumph of mathematicians, as the first whose motions were brought into recognisable obedience to the laws of gravity.[42]

'The Mussulmans, with Mahomet II. at their head, were besieging Belgrade, which was defended by Huniade, surnamed the Exterminator of the Turks. Halley's comet appeared and the two armies were seized with equal fear. Pope Calixtus III., himself seized by the general terror, ordered public prayers and timidly anathematised the comet and the enemies of Christianity. He established the prayer called the noon Angelus, the use of which is continued in all Catholic churches. The Franciscans (Freres Mineurs) brought 40,000 defenders to Belgrade, besieged by the conqueror of Constantinople, the destroyer of the Eastern Empire. At last the battle began; it continued two days without ceasing. A contest of two days caused 40,000 combatants to bite the dust. The Franciscans, unarmed, crucifix in hand, were in the front rank, invoking the papal exorcism against the comet, and turning upon the enemy that heavenly wrath of which none in those times dared doubt.'

The great comet of 1556 has been regarded as the occasion of the Emperor Charles V.'s abdication of the imperial throne; a circumstance which seems rendered a little doubtful by the fact that he had already abdicated when the comet appeared—a mere detail, perhaps, but suggesting the possibility that cause and effect may have been interchanged by mistake, and that it was Charles's abdication which occasioned the appearance of the comet. According to Gemma's account the comet was conspicuous rather from its great light than from the length of its tail or the strangeness of its appearance. 'Its head equalled Jupiter in brightness, and was equal in diameter to nearly half the apparent diameter of the moon.' It appeared about the end of February, and in March presented a terrible appearance, according to Ripamonte. 'Terrific indeed,' says Sir J. Herschel, 'it might well have been to the mind of a prince prepared by the most abject superstition to receive its appearance as a warning of approaching death, and as specially sent, whether in anger or in mercy, to detach his thoughts from earthly things, and fix them on his eternal interests. Such was its effect on the Emperor Charles V., whose abdication is distinctly ascribed by many historians to this cause, and whose words on the occasion of his first beholding it have even been recorded—

"His ergo indiciis me mea fata vocant"—

the language and the metrical form of which exclamation afford no ground for disputing its authenticity, when the habits and education of those times are fairly considered.' It is quite likely that, having already abdicated the throne, Charles regarded the comet as signalling his retirement from power—an event which he doubtless considered a great deal too important to be left without some celestial record. But the words attributed to him are in all probability apocryphal.

The comet of 1577 was remarkable for the strangeness of its aspect, which in some respects resembled that of the comet of 1858, called Donati's. It required only the terror with which such portentous objects were witnessed in the Middle Ages to transform the various streamers, curved and straight, extending from such an object, into swords and spears, and other signs of war and trouble. Doubtless, we owe to the fears of the Middle Ages the strange pictures claiming to present the actual aspect of some of the larger comets. Halley's comet did not escape. It was compared to a straight sword at one visit, to a curved scimitar in 1456, and even at its last return in 1835 there were some who recognised in the comet a resemblance to a misty head. Other comets have been compared to swords of fire, bloody crosses, flaming daggers, spears, serpents, fiery dragons, fish, and so forth. But in this respect no comet would seem to have been comparable with that of 1528, of which Andrew Pare writes as follows: 'This comet was so horrible and dreadful, and engendered such terror in the minds of men, that they died, some from fear alone, others from illness engendered by fear. It was of immense length and blood-red colour; at its head was seen the figure of a curved arm, holding a large sword in the hand as if preparing to strike. At the point of this sword were three stars; and on either side a number of axes, knives, and swords covered with blood, amongst which were many hideous human faces with bristling beards and hair.'

Such peculiarities of shape, and also those affecting the position and movements of comets, were held to be full of meaning. As Bayle pointed out in his 'Thoughts about the Comet of 1680,' these fancies are of great antiquity. Pliny tells us that in his time astrologers claimed to interpret the meaning of a comet's position and appearance, and that also of the direction towards which its rays pointed. They could, moreover, explain the effects produced by the fixed stars whose rays were conjoined with the comet's. If a comet resembles a flute, then musicians are aimed at; when comets are in the less dignified parts of the constellations, they presage evil to immodest persons; if the head of a comet forms an equilateral triangle or a square with fixed stars, then it is time for mathematicians and men of science to tremble. When they are in the sign of the Ram, they portend great wars and widespread mortality, the abasement of the great and the elevation of the small, besides fearful droughts in regions over which that sign predominates; in the Virgin, they imply many grievous ills to the female portion of the population; in the Scorpion, they portend a plague of reptiles, especially locusts; in the Fishes, they indicate great troubles from religious differences, besides war and pestilence. When, like the one described by Milton, they 'fire the length of Ophiuchus huge,' they show that there will be much mortality caused by poisoning.

The comet of 1680, which led Bayle to write the treatise to which reference has just been made, was one well calculated to inspire terror. Indeed, if the truth were known, that comet probably brought greater danger to the inhabitants of the earth than any other except the comet of 1843—the danger not, however, being that derived from possible collision between the earth and a comet, but that arising from the possible downfall of a large comet upon the sun, and the consequent enormous increase of the sun's heat. That, according to Newton, is the great danger men have to fear from comets; and the comet of 1680 was one which in that sense was a very dangerous one. There is no reason why a comet from outer space should not fall straight towards the sun, as at one time the comet of 1680 was supposed to be doing. All the comfort that science can give the world on that point is that such a course for a comet is only one out of many millions of possible courses, all fully as likely; and that, therefore, the chance of a comet falling upon the sun is only as one in many millions. Still, the comet of 1680 made a very fair shot at the sun, and a very slight modification of its course by Jupiter or Saturn might have brought about the catastrophe which Newton feared. Whether, if a comet actually fell upon the sun, anything very dreadful would happen, is not so clear. Newton's ideas respecting comets were formed in ignorance of many physical facts and laws which in our day render reasoning upon the subject comparatively easy. Yet, even in our time, it is not possible to assert confidently that such fears are idle. During the solar outburst witnessed by Carrington and Hodgson in September 1859, it is supposed that the sun swallowed a large meteoric mass; and, as great cornets are probably followed by many such masses, it seems reasonable to infer that if such a comet fell upon the sun, his surface being pelted with such exceptionally large masses, stoned with these mighty meteoric balls, would glow all over (or nearly so) as brightly as a small spot of that surface glowed upon that occasion. Now that portion was so bright that Carrington thought 'that by some chance a ray of light had penetrated a hole in the screen attached to the object-glass by which the general image is thrown in shade, for the brilliancy was fully equal to that of direct sunlight.' Manifestly, if the whole surface of the sun, or any large portion of the surface, were caused to glow with that exceeding brilliancy, surpassing ordinary sunlight in the same degree that ordinary sunlight surpassed the shaded solar image in Carrington's observations, the result would be disastrous in the extreme for the inhabitants of that half of the earth which chanced to be in sunlight at the time; and if (as could scarcely fail to happen) the duration of that abnormal splendour were more than half a day, then the whole earth would probably be depopulated by the intense heat. The danger, as I have said, is slight—partly because there is small chance of a collision between the sun and a comet, partly because we have no certain reasons for assuming that a collision would be followed by the heating of the sun for a while to a very high temperature. Looking around at the suns which people space, and considering their history, so far as it has been made known to us, for the last two thousand years, we find small occasion for fear. Those suns seem to have been for the most part safe from any sudden or rapid accessions of heat; and if they travel thus safely in their mighty journeys through space, we may well believe that our sun also is safe. Nevertheless, there have been catastrophes here and there. Now one sun and now another has blazed out with a hundred times its usual lustre, gradually losing its new fires and returning to its customary brightness; but after what destruction among those peopling its system of worlds who shall say? Spectroscopic analysis, that powerful help to the modern astronomical inquirer, has shown in one of these cases that just such changes had taken place as we might fairly expect would follow if a mighty comet fell into the sun. If this interpretation be correct, then we are not wholly safe. Any day might bring us news of a comet sailing full upon our sun from out the depths of space. Then astronomers would perhaps have the opportunity of ascertaining the harmlessness of a collision between the ruler of our system and one of the long-tailed visitors from the celestial spaces. Or possibly, astronomers and the earth's inhabitants generally might find out the reverse, though the knowledge would not avail them much, seeing that the messenger who would bring it would be the King of Terrors himself.

It was well, perhaps, that Newton's discovery of the law of gravitation, and the application of this law to the comets of 1680 and 1682 (the latter our old friend Halley's comet, then properly so called as studied by him), came in time to aid in removing to some slight degree the old superstitions respecting comets. For in England many remembered the comets of the Great Plague and of the Great Fire of London. These comets came so closely upon the time of the Plague and the Fire respectively, that it was not wonderful if even the wiser sort were struck by the coincidence and could scarcely regard it as accidental. It is not easy for the student of science in our own times, when the movements of comets are as well understood as those of the most orderly planets, to place himself in the position of men in the times when no one knew on what paths comets came, or whither they retreated after they had visited our sun. Taught as men were, on the one hand, that it was wicked to question what seemed to be the teaching of the Scriptures, that changes or new appearances in the heavens were sent to warn mankind of approaching troubles, and perplexed as they were, on the other, by the absence of any real knowledge respecting comets and meteors, it was not so easy as we might imagine from our own way of viewing these matters, to shake off a superstition which had ruled over men's minds for thousands of years.

No sect had been free from this superstition. Popes and priests had taught their followers to pray against the evil influences of comets and other celestial portents; Luther and Melanchthon had condemned in no measured terms the rashness and impiety of those who had striven to show that the heavenly bodies and the earth move in concordance with law—those 'fools who wish to reverse the entire science of astronomy.' A long interval had elapsed between the time when the Copernican theory was struggling for existence—when, but that more serious heresies engaged men's attention and kept religious folk by the ears, that astronomical heresy would probably have been quenched in blood—and the forging by Newton of the final link of the chain of reasoning on which modern astronomy is based; but in those times the minds of men moved more slowly than in ours. The masses still held to the old beliefs about the heavenly bodies. Defoe, indeed, speaking of the terror of men at the time of the Great Plague, says that they 'were more addicted to prophecies and astrological conjurations, dreams, and old wives' tales, than ever they were before or since.' But in reality, it was only because of the great misery then prevailing that men seemed more superstitious than usual; for misery brings out the superstitions—the fetishisms, if we may so speak—which are inherent in many minds, but concealed from others in prosperous times, out of shame, or perhaps a worthier feeling. Even in our own times great national calamities would show that many superstitions exist which had been thought extinct, and we should see excited among the ill-educated that particular form of persecution which arises, not from zeal for religion and not from intolerance, but from the belief that the troubles have been sent because of unbelief and the fear that unless some expiation be made the evil will not pass away from the midst of the people. It is at such times of general affliction that minds of the meaner sort have proved 'zealous even to slaying.'

The influence of strange appearances in the heavens on even thoughtful and reasoning minds, at such times of universal calamity, is well shown by Defoe's remarks on the comets of the years 1664 and 1666. 'The old women,' he says, 'and the phlegmatic, hypochondriacal part of the other sex, whom I could almost call old women too, remarked that those two comets passed directly over the city' [though that appearance must have depended on the position whence these old women, male and female, observed the comet], 'and that so very near the houses, that it was plain they imported something peculiar to the city alone; and that the comet before the Pestilence was of a faint, dull, languid colour, and its motion very heavy, solemn, and slow; but that the comet before the Fire was bright and sparkling, or, as others said, flaming, and its motion swift and furious: and that accordingly one foretold a heavy judgment, slow but severe, terrible and frightful, as was the Plague; but the other foretold a stroke, sudden, swift, and fiery, as was the Conflagration. Nay, so particular some people were, that, as they looked upon that comet preceding the Fire, they fancied that they not only saw it pass swiftly and fiercely, and could perceive the motion with their eye, but even that they heard it; that it made a mighty rushing noise, fierce and terrible, though at a distance and but just perceivable. I saw both these stars, and must confess had I had so much the common notion of such things in my head, that I was apt to look upon them as the forerunners and warnings of God's judgments, and especially when, the Plague having followed the first, I yet saw another of the same kind, I could not but say, God had not yet sufficiently scourged the city' [London].

The comets of 1680 and 1682, though they did not bring plagues or conflagrations immediately, yet were not supposed to have been altogether without influence. The convenient fiction, indeed, that some comets operate quickly and others slowly, made it very difficult for a comet to appear to which some evil effects could not be ascribed. If any one can find a single date, since the records of history have been carefully kept, which was so fortunately placed that, during no time following it within five years, no prince, king, emperor, or pope died, no war was begun, or ended disastrously for one side or the other engaged in it, no revolution was effected, neither plague nor pestilence occurred, neither droughts nor floods afflicted any nation, no great hurricanes, earthquakes, volcanic outbursts, or other trouble was recorded, he will then have shown the bare possibility that a comet might have appeared which seemed to presage neither abrupt nor slow-moving calamities. But it is not possible to name such a date, nor even a date which was not followed within two years at the utmost by a calamity such as superstition might assign to a comet. And so closely have such calamities usually followed, that scarce a comet could appear which might not be regarded as the precursor of very quickly approaching calamity. Even if a comet had come which seemed to bring no trouble, nay, if many such comets had come, men would still have overlooked the absence of any apparent fulfilment of the predicted troubles. Henry IV. well remarked, when he was told that astrologers predicted his death because a certain comet had been observed: 'One of these days they will predict it truly, and people will remember better the single occasion when the prediction will be fulfilled than the many other occasions when it has been falsified by the event.'

The troubles connected with the comets of 1680 and 1682 were removed farther from the dates of the events themselves than usual, at least so far as the English interpretation of the comets was concerned. 'The great comet in 1680,' says one, 'followed by a lesser comet in 1682, was evidently the forerunner of all those remarkable and disastrous events that ended in the revolution of 1688. It also evidently presaged the revocation of the edict of Nantes, and the cruel persecution of the Protestants, by the French king Louis XIV., afterwards followed by those terrible wars which, with little intermission, continued to ravage the finest parts of Europe for nearly twenty-four years.'

If in some respects the fears inspired by comets have been reduced by modern scientific discoveries respecting these bodies, yet in other respects the very confidence engendered by the exactness of modern astronomical computations has proved a source of terror. There is nothing more remarkable, for instance, in the whole history of cometary superstition, than the panic which spread over France in the year 1773, in consequence of a rumour that the mathematician Lalande had predicted the occurrence of a collision between a comet and the earth, and that disastrous effects would inevitably follow. The foundation of the rumour was slight enough in all conscience. It had simply been announced that Lalande would read before the Academy of Sciences a paper entitled 'Reflections on those Comets which can approach the Earth.' That was absolutely all; yet, from that one fact, not only were vague rumours of approaching cometic troubles spread abroad, but the statement was definitely made that on May 20 or 21, 1773, 'a comet would encounter the earth.'[43] So great was the fear thus excited, that, in order to calm it, Lalande inserted in the 'Gazette de France' of May 7, 1773, the following advertisement:—'M. Lalande had not time to read his memoir upon comets which may approach the earth and cause changes in her motions; but he would observe that it is impossible to assign the epochs of such events. The next comet whose return is expected is the one which should return in eighteen years; but it is not one of those which can hurt the earth.'

This note had not the slightest effect in restoring peace to the minds of unscientific Frenchmen. M. Lalande's study was crowded with anxious persons who came to inquire about his memoir. Certain devout folk, 'as ignorant as they were imbecile,' says a contemporary journal, begged the Archbishop of Paris to appoint forty hours' prayer to avert the danger and prevent the terrible deluge. For this was the particular form most men agreed that the danger would take. That prelate was on the point, indeed, of complying with their request, and would have done so, but that some members of the Academy explained to him that by so doing he would excite ridicule.

Far more effective, and, to say truth, far better judged, was the irony of Voltaire, in his deservedly celebrated 'Letter on the Pretended Comet.' It ran as follows:—

'Grenoble, May 17, 1773.

'Certain Parisians who are not philosophers, and who, if we are to believe them, will not have time to become such, have informed me that the end of the world approaches, and will occur without fail on the 20th of this present month of May. They expect, that day, a comet, which is to take our little globe from behind and reduce it to impalpable powder, according to a certain prediction of the Academy of Sciences which has not yet been made.

'Nothing is more likely than this event; for James Bernouilli, in his "Treatise upon the Comet" of 1680, predicted expressly that the famous comet of 1680 would return with terrible uproar (fracas) on May 19, 1719; he assured us that in truth its perruque would signify nothing mischievous, but that its tail would be an infallible sign of the wrath of heaven. If James Bernouilli mistook, it is, after all, but a matter of fifty-four years and three days.

'Now, so small an error as this being regarded by all geometricians as of little moment in the immensity of ages, it is manifest that nothing can be more reasonable than to hope (sic, esperer) for the end of the world on the 20th of this present month of May 1773, or in some other year. If the thing should not come to pass, "omittance is no quittance" (ce qui est differe, n'est pas perdu).

'There is certainly no reason for laughing at M. Trissotin, triple idiot though he is (tout Trissotin qu'il est), when he says to Madame Philaminte (Moliere's "Femmes Savantes," acte iv. scene 3),

'Nous l'avons en dormant, madame, echappe belle; Un monde pres de nous a passe tout du long, Est chu tout au travers de notre tourbillon; Et, s'il eut en chemin rencontre notre terre, Elle eut ete brisee en morceaux comme verre.

'A comet coursing along its parabolic orbit may come full tilt against our earth. But then, what will happen? Either that comet will have a force equal to that of our earth, or greater, or less. If equal, we shall do the comet as much harm as it will do us, action and reaction being equal; if greater, the comet will bear us away with it; if less, we shall bear away the comet.

'This great event may occur in a thousand ways, and no one can affirm that our earth and the other planets have not experienced more than one revolution, through the mischance of encountering a comet on their path.

'The Parisians will not desert their city on the 20th inst.; they will sing songs, and the play of "The Comet and the World's End" will be performed at the Opera Comique.'

The last touch is as fine in its way as Sydney Smith's remark that, if London were destroyed by an earthquake, the surviving citizens would celebrate the event by a public dinner among the ruins. Voltaire's prediction was not fulfilled exactly to the letter, but what actually happened was even funnier than what his lively imagination had suggested. It was stated by a Parisian Professor in 1832 (as a reason why the Academy of Sciences should refute an assertion then rife to the effect that Biela's comet would encounter the earth that year) that during the cometic panic of 1773 'there were not wanting people who knew too well the art of turning to their advantage the alarm inspired by the approaching comet, and places in Paradise were sold at a very high rate.[44] The announcement of the comet of 1832 may produce similar effects,' he said, 'unless the authority of the Academy apply a prompt remedy; and this salutary intervention is at this moment implored by many benevolent persons.'

In recent years the effects produced on the minds of men by comets have been less marked than of yore, and appear to have depended a good deal on circumstances. The comet of the year 1858 (called Donati's), for example, occasioned no special fears, at least until Napoleon III. made his famous New-Year's day speech, after which many began to think the comet had meant mischief. But the comet of 1861, though less conspicuous, occasioned more serious fears. It was held by many in Italy to presage a very great misfortune indeed, viz. the restoration of Francis II. to the throne of the Two Sicilies. Others thought that the downfall of the temporal power of the Papacy and the death of Pope Pius IX. were signified. I have not heard that any very serious consequences were expected to follow the appearance of Coggia's comet in 1874. The great heat which prevailed during parts of the summer of 1876 was held by many to be connected in some way with a comet which some very unskilful telescopist constructed in his imagination out of the glare of Jupiter in the object-glass of his telescope. Another benighted person, seeing the Pleiades low down through a fog, turned them into a comet, about the same time. Possibly the idea was, that since comets are supposed to cause great heats, great heats may be supposed to indicate a comet somewhere; and with minds thus prepared, it was not wonderful, perhaps, that telescopic glare, or an imperfect view of our old friends the Pleiades, should have been mistaken for a vision of the heat-producing comet.

It should be a noteworthy circumstance to those who still continue to look on comets as signs of great catastrophes, that a war more remarkable in many respects than any which has ever yet been waged between two great nations—a war swift in its operations and decisive in its effects—a war in which three armies, each larger than all the forces commanded by Napoleon I. during the campaign of 1813, were captured bodily—should have been begun and carried on to its termination without the appearance of any great comet. The civil war in America, a still more terrible calamity to that great nation than the success of Moltke's operations to the French, may be regarded by believers as presignified by the great comet of 1861. But it so chances that the war between France and Germany occurred near the middle of one of the longest intervals recorded in astronomical annals as unmarked by a single conspicuous comet—the interval between the years 1862 and 1874.

If the progress of just ideas respecting comets has been slow, it must nevertheless be regarded as on the whole satisfactory. When we remember that it was not a mere idle fancy which had to be opposed, not mere terrors which had to be calmed, but that the idea of the significance of changes in the heavens had come to be regarded by mankind as a part of their religion, it cannot but be thought a hopeful sign that all reasoning men in our time have abandoned the idea that comets are sent to warn the inhabitants of this small earth. Obeying in their movements the same law of gravitation which guides the planets in their courses, the comets are tracked by the skilful mathematician along those remote parts of their course where even the telescope fails to keep them in view. Not only are they no longer regarded as presaging the fortunes of men on this earth, but men on this earth are able to predict the fortunes of comets. Not only is it seen that they cannot influence the fates of the earth or other planets, but we perceive that the earth and planets by their attractive energies influence, and in no unimportant degree, the fates of these visitants from outer space. Encouraging, truly, is the lesson taught us by the success of earnest study and careful inquiry in determining some at least among the laws which govern bodies once thought the wildest and most erratic creatures in the whole of God's universe.



IX.

THE LUNAR HOAX.

Then he gave them an account of the famous moon hoax, which came out in 1835. It was full of the most barefaced absurdities, yet people swallowed it all; and even Arago is said to have treated it seriously as a thing that could not well be true, for Mr. Herschel would have certainly notified him of these marvellous discoveries. The writer of it had not troubled himself to invent probabilities, but had borrowed his scenery from the 'Arabian Nights' and his lunar inhabitants from 'Peter Wilkins.'—OLIVER WENDELL HOLMES (in The Poet at the Breakfast-Table).

In one of the earliest numbers of 'Macmillan's Magazine, the late Professor De Morgan, in an article on Scientific Hoaxing, gave a brief account of the so-called 'lunar hoax'—an instance of scientific trickery frequently mentioned, though probably few are familiar with the real facts. De Morgan himself possessed a copy of the second English edition of the pamphlet, published in London in 1836. But the original pamphlet edition, published in America in September 1835, is not easily to be obtained. The proprietors of the New York 'Sun,' in which the fictitious narrative first appeared, published an edition of 60,000 copies, and every copy was sold in less than a month. Lately a single copy of that edition was sold for three dollars seventy-five cents.[45]

The pamphlet is interesting in many respects, and I propose to give here a brief account of it. But first it may be well to describe briefly the origin of the hoax.

It is said that after the French revolution of 1830 Nicollet, a French astronomer of some repute, especially for certain lunar observations of a very delicate and difficult kind, left France in debt and also in bad odour with the republican party. According to this story, Arago the astronomer was especially obnoxious to Nicollet, and it was as much with the view of revenging himself on his foe as from a wish to raise a little money that Nicollet wrote the moon-fable. It is said further that Arago was entrapped, as Nicollet desired, and circulated all over Paris the wonders related in the pamphlet, until Nicollet wrote to his friend Bouvard explaining the trick. So runs the story, but the story cannot be altogether true. Nicollet may have prepared the narrative and partly written it, but there are passages in the pamphlet as published in America which no astronomer could have written. Possibly there is some truth in De Morgan's supposition that the original work was French. This may have been Nicollet's: and the American edition was probably enlarged by the translator, who, according to this account, was Richard Alton Locke,[46] to whom in America the whole credit, or discredit, of the hoax is commonly attributed. There can be no doubt that either the French version was much more carefully designed than the American, or there was no truth in the story that Arago was deceived by the narrative; for in its present form the story, though clever, could not for an instant have deceived any one acquainted with the most elementary laws of optics. The whole story turns on optical rather than on astronomical considerations; but every astronomer of the least skill is acquainted with the principles on which the construction of optical instruments depends. Though the success of the deception recently practised on M. Chasles by the forger of the Pascal papers has been regarded as showing how easily mathematicians may be entrapped, yet even M. Chasles would not have been deceived by bad mathematics; and Arago, a master of the science of optics, could not but have detected optical blunders which would be glaring to the average Cambridge undergraduate.

But let us turn to the story itself.

The account opens with a passage unmistakably from an American hand, though purporting, be it remembered, to be quoted from the 'Supplement to the Edinburgh Journal of Science.' 'In this unusual addition to our journal, we have the happiness of making known to the British public, and thence to the whole civilised world, recent discoveries in astronomy which will build an imperishable monument to the age in which we live, and confer upon the present generation of the human race a proud distinction through all future time. It has been poetically said' [where and by whom?] 'that the stars of heaven are the hereditary regalia of man, as the intellectual sovereign of the animal creation. He may now fold the zodiac around him with a loftier consciousness of his mental supremacy.' To the American mind enwrapment in the star-jewelled zodiac may appear as natural as their ordinary oratorical references to the star-spangled banner; but the idea is essentially transatlantic, and not even the most poetical European astronomer could have risen to such a height of imagery.

Passing over several pages of introductory matter, we come to the description of the method by which a telescope of sufficient magnifying power to show living creatures in the moon was constructed by Sir John Herschel. It had occurred, it would seem, to the elder Herschel to construct an improved series of parabolic and spherical reflectors 'uniting all the meritorious points in the Gregorian and Newtonian instruments, with the highly interesting achromatic discovery of Dolland'(sic). [This is much as though one should say that a clever engineer had conceived the idea of constructing an improved series of railway engines, combining all the meritorious points in stationary and locomotive engines, with Isaac Watts' highly ingenious discovery of screw propulsion. For the Gregorian and Newtonian instruments simply differ in sending the rays received from the great mirror in different directions, and Dolland's discovery relates to the ordinary forms of telescopes with large lens, not with large mirror.] However, accumulating infirmities and eventually death prevented Sir William Herschel from applying his plan, which 'evinced the most profound research in optical science, and the most dexterous ingenuity in mechanical contrivance. But his son, Sir John Herschel, nursed and cradled in the observatory, and a practical astronomer from his boyhood, determined upon testing it at whatever cost. Within two years of his father's death he completed his new apparatus, and adapted it to the old telescope with nearly perfect success.' A short account of the observations made with this instrument, now magnifying six thousand times, follows, in which most of the astronomical statements are very correctly and justly worded, being, in fact, borrowed from a paper by Sir W. Herschel on observation of the moon with precisely that power.

But this great improvement upon all former telescopes still left the observer at a distance of forty miles from the moon; and at that distance no object less than about twenty yards in diameter could be distinguished, and even objects of that size 'would appear only as feeble, shapeless points.' Sir John 'had the satisfaction to know that if he could leap astride a cannon-ball, and travel upon its wings of fury for the respectable period of several millions of years, he would not obtain a more enlarged view of the more distant stars than he could now possess in a few minutes of time; and that it would require an ultra-railroad speed of fifty miles an hour for nearly the livelong year, to secure him a more favourable inspection of the gentle luminary of the night;' but 'the exciting question whether this "observed" of all the sons of men, from the days of Eden to those of Edinburgh, be inhabited by beings, like ourselves, of consciousness and curiosity, was left to the benevolent index of natural analogy, or to the severe tradition that the moon is tenanted only by the hoary solitaire, whom the criminal code of the nursery had banished thither for collecting fuel on the Sabbath-day.'[47] But the time had arrived when the great discovery was to be made, by which at length the moon could be brought near enough, by telescopic power, for living creatures on her surface to be seen if any exist.

The account of the sudden discovery of the new method, during a conversation between Sir John Herschel and Sir David Brewster, is one of the most cleverly conceived (though also one of the absurdest) passages in the pamphlet. 'About three years ago, in the course of a conversational discussion with Sir David Brewster upon the merits of some ingenious suggestions by the latter, in his article on Optics in the "Edinburgh Encyclopaedia," p. 644, for improvements in Newtonian reflectors, Sir John Herschel adverted to the convenient simplicity of the old astronomical telescopes that were without tubes, and the object-glass of which, placed upon a high pole, threw the focal image to a distance of 150 and even 200 feet. Dr. Brewster readily admitted that a tube was not necessary, provided the focal image were conveyed into a dark apartment and there properly received by reflectors.... The conversation then became directed to that all-invincible enemy, the paucity of light in powerful magnifiers. After a few moments' silent thought, Sir John diffidently enquired whether it would not be possible to effect a transfusion of artificial light through the focal object of vision! Sir David, somewhat startled at the originality of the idea, paused awhile, and then hesitatingly referred to the refrangibility of rays, and the angle of incidence. Sir John, grown more confident, adduced the example of the Newtonian reflector, in which the refrangibility was corrected by the second speculum, and the angle of incidence restored by the third.'

All this part of the narrative is simply splendid in absurdity. Hesitating references to refrangibility and the angle of incidence would have been sheerly idiotic under the supposed circumstances; and in the Newtonian reflector (which has only two specula or mirrors) there is no refrangibility to be corrected; apart from which, 'correcting refrangibility' has no more meaning than 'restoring the angle of incidence.'

'"And," continued Sir John, "why cannot the illuminating microscope, say the hydro-oxygen, be applied to render distinct, and, if necessary, even to magnify, the focal object?" Sir David sprung from his chair' [and well he might, though not] 'in an ecstasy of conviction, and, leaping half-way to the ceiling, exclaimed, "Thou art the man!" Each philosopher anticipated the other in presenting the prompt illustration that if the rays of the hydro-oxygen microscope, passed through a drop of water containing the larvae of a gnat and other objects invisible to the naked eye, rendered them not only keenly but firmly magnified to dimensions of many feet; so could the same artificial light, passed through the faintest focal object of a telescope, both distinctify (to coin a new word for an extraordinary occasion) and magnify its feeblest component members. The only apparent desideratum was a recipient for the focal image which should transfer it, without refranging it, to the surface on which it was to be viewed under the revivifying light of the microscopic reflectors.'

Singularly enough, the idea here mentioned does not appear to many so absurd as it is in reality. It is known that the image formed by the large lens of an ordinary telescope or the large mirror of a reflecting telescope is a real image; not a merely virtual image like that which is seen in a looking-glass. It can be received on a sheet of paper or other white surface just as the image of surrounding objects can be thrown upon the white table of the camera obscura. It is this real image, in fact, which we look at in using a telescope of any sort, the portion of such a telescope nearest to the eye being in reality a microscope for viewing the image formed by the great lens or mirror, as the case may be. And it does not seem to some altogether absurd to speak of illuminating this image by transfused light, or of casting by means of an illuminating microscope a vastly enlarged picture of this image upon a screen. But of course the image being simply formed by the passage of rays (which originally came from the object whose image they form) through a certain small space, to send other rays (coming from some other luminous object) through the same small space, is not to improve, but, so far as any effect is produced at all, to impair, the distinctness of the image. In fact, if these illuminating rays reached the eye, they would seriously impair the distinctness of the image. Their effect may be compared exactly with the effect of rays of light cast upon the image in a camera obscura; and, to see what the effect of such rays would be, we need only consider why it is that the camera is made 'obscura,' or dark. The effect of the transfusion of light through a telescopic image may be easily tried by any one who cares to make the experiment. He has only to do away with the tube of his telescope (substituting two or three straight rods to hold the glass in its place), and then in the blaze of a strong sun to direct the telescope on some object lying nearly towards the sun. Or if he prefer artificial light for the experiment, then at night let him direct the telescope so prepared upon the moon, while a strong electric light is directed upon the place where the focal image is formed (close in front of the eye). The experiment will not suggest very sanguine hopes of good result from the transfusion of artificial light. Yet, to my own knowledge, not a few who were perfectly well aware that the lunar hoax was not based on facts, have gravely reasoned that the principle suggested might be sound, and, in fact, that they could see no reason why astronomers should not try it, even though it had been first suggested as a joke.

To return, however, to the narrative. 'The co-operative philosophers, having hit upon their method, determined to test it practically. They decided that a medium of the purest plate-glass (which it is said they obtained, by consent, be it observed, from the shop-window of M. Desanges, the jeweller to his ex-majesty Charles X., in High Street) was the most eligible they could discover. It answered perfectly with a telescope which magnified a hundred times, and a microscope of about thrice that power.' Thus fortified by experiment, and 'fully sanctioned by the high optical authority of Sir David Brewster, Sir John laid his plan before the Royal Society, and particularly directed to it the attention of his Royal Highness the Duke of Sussex, the ever munificent patron of science and the arts. It was immediately and enthusiastically approved by the committee chosen to investigate it, and the chairman, who was the Royal President' (this continual reference to royalty is manifestly intended to give a British tone to the narrative), 'subscribed his name for a contribution of L10,000, with a promise that he would zealously submit the proposed instrument as a fit object for the patronage of the privy purse. He did so without delay; and his Majesty, on being informed that the estimated expense was L70,000, naively enquired if the costly instrument would conduce to any improvement in navigation. On being informed that it undoubtly would, the sailor king promised a carte blanche for any amount which might be required.'

All this is very clever. The 'sailor king' comes in as effectively to give vraisemblance to the narrative as 'Crabtree's little bronze Shakspeare that stood over the fireplace,' and the 'postman just come to the door with a double letter from Northamptonshire.'

Then comes a description of the construction of the object-glass, twenty-four feet in diameter, 'just six times the size of the elder Herschel's;' who, by the way, never made a telescope with an object-glass. The account of Sir John Herschel's journey from England, and even some details of the construction of the observatory, were based on facts, indeed, so many persons in America as well as in England were acquainted with some of these circumstances, that it was essential to follow the facts as closely as possible. Of course, also, some explanation had to be given of the circumstance that nothing had before been heard respecting the gigantic instrument taken out by Sir John Herschel. 'Whether,' says the story, 'the British Government were sceptical concerning the promised splendour of the discoveries, or wished them to be scrupulously veiled until they had accumulated a full-orbed glory for the nation and reign in which they originated, is a question which we can only conjecturally solve. But certain it is that the astronomer's royal patrons enjoined a masonic taciturnity upon him and his friends until he should have officially communicated the results of his great experiment.'

It was not till the night of January 10, 1835, that the mighty telescope was at length directed towards our satellite. The part of the moon selected was on the eastern part of her disc. 'The whole immense power of the telescope was applied, and to its focal image about one half of the power of the microscope. On removing the screen of the latter, the field of view was covered throughout its entire area with a beautifully distinct and even vivid representation of basaltic rock. Its colour was a greenish brown; and the width of the columns, as defined by their interstices on the canvas, was invariably twenty-eight inches. No fracture whatever appeared in the mass first presented; but in a few seconds a shelving pile appeared, of five or six columns' width, which showed their figure to be hexagonal, and their articulations similar to those of the basaltic formation at Staffa. This precipitous cliff was profusely covered with a dark red flower, precisely similar, says Dr. Grant, to the Papaver Rhoeus, or Rose Poppy, of our sublunary cornfields; and this was the first organic production of nature in a foreign world ever revealed to the eyes of men.'

It would be wearisome to go through the whole series of observations thus fabled, and only a few of the more striking features need be indicated. The discoveries are carefully graduated in interest. Thus we have seen how, after recognising basaltic formations, the observers discovered flowers: they next see a lunar forest, whose 'trees were of one unvaried kind, and unlike any on earth except the largest kind of yews in the English churchyards.' (There is an American ring in this sentence, by the way, as there is in one, a few lines farther on, where the narrator having stated that by mistake the observers had the Sea of Clouds instead of a more easterly spot in the field of view, proceeds to say: 'However, the moon was a free country, and we not as yet attached to any particular province.') Next a lunar ocean is described, 'the water nearly as blue as that of the deep sea, and breaking in large white billows upon the strand, while the action of very high tides was quite manifest upon the face of the cliffs for more than a hundred miles.' After a description of several valleys, hills, mountains and forests, we come to the discovery of animal life. An oval valley surrounded by hills, red as the purest vermilion, is selected as the scene. 'Small collections of trees, of every imaginable kind, were scattered about the whole of this luxuriant area; and here our magnifiers blessed our panting hopes with specimens of conscious existence. In the shade of the woods we beheld brown quadrupeds having all the external characteristics of the bison, but more diminutive than any species of the bos genus in our natural history.' Then herds of agile creatures like antelopes are described, 'abounding on the acclivitous glades of the woods.' In the contemplation of these sprightly animals the narrator becomes quite lively. 'This beautiful creature,' says he, 'afforded us the most exquisite amusement. The mimicry of its movements upon our white painted canvas was as faithful and luminous as that of animals within a few yards of the camera obscura. Frequently, when attempting to put our fingers upon its beard, it would suddenly bound away as if conscious of our earthly impertinence; but then others would appear, whom we could not prevent nibbling the herbage, say or do to them what we would.'

A strange amphibious creature, of a spherical form, rolling with great velocity along a pebbly beach, is the next object of interest, but is presently lost sight of in a strong current setting off from the angle of an island. After this there are three or four pages descriptive of various lunar scenes and animals, the latter showing a tendency, singular considering the circumstances, though very convenient for the narrator, to become higher and higher in type as the discoveries proceed, until an animal somewhat of the nature of the missing link is discovered. It is found in the Endymion (a circular walled plain) in company with a small kind of reindeer, the elk, the moose, and the horned bear, and is described as the biped beaver. It 'resembles the beaver of the earth in every other respect than in its destitution of a tail, and its invariable habit of walking upon only two feet. It carries its young in its arms like a human being, and moves with an easy gliding motion. Its huts are constructed better and higher than those of many tribes of human savages, and, from the appearance of smoke in nearly all of them, there is no doubt of its being acquainted with the use of fire. Still, its head and body differ only in the points stated from that of the beaver; and it was never seen except on the borders of lakes and rivers, in which it has been observed to immerse for a period of several seconds.'