CONTENTS. (continued 5)

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 Cæsar; and, in our own time, when, Claudius Cæsar 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 Pingré, 'was that of the year 814, presaging the death of Charlemagne.' So Guillemin quotes Pingré; 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 Cæsar; 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:

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 (Frères 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—

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 Paré 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, espérer) 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 différé, 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 (Molière's "Femmes Savantes," acte iv. scène 3),

'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 Opéra 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 Encyclopædia," 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 larvæ 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 £10,000, 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 £70,000, naïvely 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 Rhœus, 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.'

The next step towards the climax brings us to domestic animals, 'good large sheep, which would not have disgraced the farms of Leicestershire or the shambles of Leadenhall Market; we fairly laughed at the recognition of so familiar an acquaintance in so distant a land. Presently they appeared in great numbers, and, on reducing the lenses, we found them in flocks over a great part of the valley. I need not say how desirous we were of finding shepherds to these flocks, and even a man with blue apron and rolled-up sleeves would have been a welcome sight to us, if not to the sheep; but they fed in peace, lords of their own pastures, without either protector or destroyer in human shape.'

In the meantime, discussion had arisen as to the lunar locality where men, or creatures resembling them, would most likely be found. Herschel had a theory on the subject—viz., that just where the balancing or libratory swing of the moon brings into view the greatest extent beyond the eastern or western parts of that hemisphere which is turned earthwards in the moon's mean or average position, lunar inhabitants would probably be found, and nowhere else. This, by the way (speaking seriously), is a rather curious anticipation of a view long subsequently advanced by Hansen, and for a time adopted by Sir J. Herschel, that possibly the remote hemisphere of the moon may be a fit abode for living creatures, the oceans and atmosphere which are wanting on the nearer hemisphere having been (on this hypothesis) drawn over to the remoter because of a displacement of the moon's centre of gravity. I ventured in one of my first books on astronomy to indicate objections to this theory, the force of which Sir J. Herschel admitted in a letter addressed to me on the subject.

Taking, then, an opportunity when the moon had just swung to the extreme limit of her balancing, or, to use technical terms, when she had attained her maximum libration in longitude, the observers approached the level opening to Lake Langrenus, as the narrator calls this fine walled plain, which, by the way, is fully thirty degrees of lunar longitude within the average western limit of the moon's visible hemisphere. 'Here the valley narrows to a mile in width, and displays scenery on both sides picturesque and romantic beyond the powers of a prose description. Imagination, borne on the wings of poetry, could alone gather similes to portray the wild sublimity of this landscape, where dark behemoth crags stood over the brows of lofty precipices, as if a rampart in the sky; and forests seemed suspended in mid-air. On the eastern side there was one soaring crag, crested with trees, which hung over in a curve like three-fourths of a Gothic arch, and being of a rich crimson colour, its effect was most strange upon minds unaccustomed to the association of such grandeur with such beauty. But, whilst gazing upon them in a perspective of about half a mile, we were thrilled with astonishment to perceive four successive flocks of large winged creatures, wholly unlike any kind of birds, descend with a slow even motion from the cliffs on the western side and alight upon the plain. They were first noticed by Dr. Herschel, who exclaimed: "Now, gentlemen, my theories against your proofs, which you have often found a pretty even bet, we have here something worth looking at. I was confident that if ever we found beings in human shape it would be in this longitude, and that they would be provided by their Creator with some extraordinary powers of locomotion." ... We counted three parties of these creatures, of twelve, nine, and fifteen in each, walking erect towards a small wood near the base of the eastern precipices. Certainly they were like human beings, for their wings had now disappeared, and their attitude in walking was both erect and dignified.... They averaged four feet in height, were covered, except on the face, with short and glossy copper-coloured hair, lying snugly upon their backs, from the top of the shoulders to the calves of the legs. The face, which was of a yellowish flesh colour, was a slight improvement upon that of the large orang outang, being more open and intelligent in its expression, and having a much greater expansion of forehead. The mouth, however, was very prominent, though somewhat relieved by a thick beard upon the lower jaw, and by lips far more human than those of any species of the simia genus. In general symmetry of body and limbs they were infinitely superior to the orang outang; so much so, that, but for their long wings, Lieutenant Drummond said they would look as well on a parade ground as some of the old Cockney militia.... These creatures were evidently engaged in conversation; their gesticulation, more particularly the varied action of their hands and arms, appeared impassioned and emphatic. We hence inferred that they were rational beings, and, although not perhaps of so high an order as others which we discovered the next month on the shores of the Bay of Rainbows, that they were capable of producing works of art and contrivance.... They possessed wings of great expansion, similar in construction to those of the bat, being a semi-transparent membrane united in curvilinear divisions by means of straight radii, united at the back by the dorsal integuments. But what astonished us very much was the circumstance of this membrane being continued from the shoulders to the legs, united all the way down, though gradually decreasing in width' (very much as Fuseli depicted the wings of his Satanic Majesty, though H.S.M. would seem to have the advantage of the lunar Bat-men in not being influenced by gravity[48]). 'The wings seemed completely under the command of volition, for those of the creatures whom we saw bathing in the water spread them instantly to their full width, waved them as ducks do theirs to shake off the water, and then as instantly closed them again in a compact form. Our further observation of the habits of these creatures, who were of both sexes, led to results so very remarkable, that I prefer they should be first laid before the public in Dr. Herschel's own work, where I have reason to know they are fully and faithfully stated, however incredulously they may be received.... We scientifically denominated them the Vespertilio-homo or Bat-man; and they are doubtless innocent and happy creatures, notwithstanding that some of their amusements would but ill comport with our terrestrial notions of decorum.' The omitted passages were suppressed in obedience to Dr. Grant's private injunction. 'These, however, and other prohibited passages,' were to be presently 'published by Dr. Herschel, with the certificates of the civil and military authorities of the colony, and of several Episcopal, Wesleyan, and other ministers, who in the month of March last were permitted, under stipulation of temporary secrecy, to visit the observatory, and become eye-witnesses of the wonders which they were requested to attest. We are confident that his forthcoming volumes will be at once the most sublime in science, and the most intense in general interest, that ever issued from the press.'

The actual climax of the narrative, however, is not yet reached. The inhabitants of Langrenus, though rational, do not belong to the highest orders of intelligent Lunarians. Herschel, ever ready with theories, had pointed out that probably the most cultivated races would be found residing on the slopes of some active volcano, and, in particular, that the proximity of the flaming mountain Bullialdus (about twenty degrees south and ten east of the vast crater Tycho, the centre whence extend those great radiations which give to the moon something of the appearance of a peeled orange) 'must be so great a local convenience to dwellers in this valley during the long periodical absence of solar light, as to render it a place of popular resort for the inhabitants of all the adjacent regions, more especially as its bulwark of hills afforded an infallible security against any volcanic eruption that could occur.' Our observers therefore applied their full power to explore it. 'Rich, indeed, was our reward. The very first object in this valley that appeared upon our canvas was a magnificent work of art. It was a temple—a fane of devotion or of science, which, when consecrated to the Creator, is devotion of the loftiest order, for it exhibits His attributes purely, free from the masquerade attire and blasphemous caricature of controversial creeds, and has the seal and signature of His own hand to sanction its aspirations. It was an equi-angular temple, built of polished sapphire, or of some resplendent blue stone, which, like it, displayed a myriad point of golden light twinkling and scintillating in the sunbeams.... The roof was composed of yellow metal, and divided into three compartments, which were not triangular planes inclining to the centre, but subdivided, curved, and separated so as to present a mass of violently agitated flames rising from a common source of conflagration, and terminating in wildly waving points. This design was too manifest and too skilfully executed to be mistaken for a single moment. Through a few openings in these metallic flames we perceived a large sphere of a darker kind of metal nearly of a clouded copper colour, which they enclosed and seemingly raged around, as if hieroglyphically consuming it.... What did the ingenious builders mean by the globe surrounded by flames? Did they, by this, record any past calamity of their world, or predict any future one of ours?' (Why, by the way, should the past theory be assigned to the moon and the future one to our earth?) 'I by no means despair of ultimately solving not only these but a thousand other questions which present themselves respecting the objects in this planet; for not the millionth part of her surface has yet been explored, and we have been more desirous of collecting the greatest possible number of new facts than of indulging in speculative theories, however seductive to the imagination.'

After this we have an account of the behaviour of the Vespertilio-homo at meals. 'They seemed eminently happy, and even polite; for individuals would select large and bright specimens of fruit, and throw them archwise across to some friend who had extracted the nutriment from those scattered around him.' However, the lunar men are not on the whole particularly interesting beings according to this account. 'So far as we could judge, they spent their happy hours in collecting various fruits in the woods, in eating, flying, bathing, and loitering about the summits of precipices.' One may say of them what Huxley is reported to have said of the spirits as described by spiritualists, that no student of science would care to waste his time inquiring about such a stupid set of people.

Such are the more interesting and characteristic portions of a narrative, running in the original to forty or fifty large octavo pages. In its day the story attracted a good deal of notice, and, even when every one had learned the trick, many were still interested in a brochure which was so cleverly conceived and had deceived so many. To this day the lunar hoax is talked of in America, where originally it had its chief—or, one may rather say, its only real—success as a hoax. It reached England too late to deceive any but those who were unacquainted with Herschel's real doings, and no editors of public journals, I believe, gave countenance to it at all. In America, on the contrary, many editors gave the narrative a distinguished place in their columns. Some indeed expressed doubts, and others followed the safe course of the 'Philadelphia Inquirer,' which informed its readers that 'after an attentive perusal of the whole story they could decide for themselves;' adding that, 'whether true or false, the narrative is written with consummate ability and possesses intense interest.' But others were more credulous. According to the 'Mercantile Advertiser' the story carried 'intrinsic evidence of being an authentic document.' The 'Albany Daily Advertiser' had read the article 'with unspeakable emotions of pleasure and astonishment.' The 'New York Times' announced that 'the writer (Dr. Andrew Grant) displays the most extensive and accurate knowledge of astronomy; and the description of Sir John's recently improved instruments, the principle on which the inestimable improvements were founded, the account of the wonderful discoveries in the moon, etc., all are probable and plausible, and have an air of intense verisimilitude.' The 'New Yorker' considered the discoveries 'of astounding interest, creating a new era in astronomy and science generally.'[49]

In our time a trick of the kind could hardly be expected to succeed so well, even if as cleverly devised and as well executed. The facts of popular astronomy and of general popular science have been more widely disseminated. America, too, more than any other great nation, has advanced in the interval. It was about two years after this pamphlet had appeared, that J. Quincy Adams used the following significant language in advocating the erection of an astronomical observatory at Washington: 'It is with no feeling of pride as an American that the remark may be made, that on the comparatively small territorial surface of Europe there are existing more than 130 of these lighthouses of the skies; while throughout the whole American hemisphere there is but one.' At present, some of the finest observatories in the world belong to American cities, or are attached to American colleges; and much of the most interesting astronomical work of this country has been achieved by American observers.

Yet we still hear from time to time of the attempted publication of hoaxes of greater or less ingenuity. It is singular (and I think significant) how often these relate to the moon. There would seem to be some charm about our satellite for the minds of paradoxists and hoaxers generally. Nor are these tricks invariably detected at once by the general public, or even by persons of some culture. I remember being gravely asked (in January 1874) whether an account given in the 'New York World,' purporting to describe how the moon's frame was gradually cracking, threatening eventually to fall into several separate fragments, was in reality based on fact. In the far West, at Lincoln, Nebraska, a lawyer asked me, not long since, why I had not described the great discoveries recently made by means of a powerful reflector erected near Paris. According to the 'Chicago Times,' this powerful instrument had shown buildings in the moon, and bands of workers could be seen with it who manifestly were undergoing some kind of penal servitude, for they were chained together. It was clear, from the presence of these and the absence of other inhabitants, that the side of the moon turned earthwards is a dreary and unpleasant place of abode, the real 'happy hunting grounds' of the moon lying on her remote and unseen hemisphere.

As gauges of general knowledge, scientific hoaxes have their uses, just as paradoxical works have. No one, certainly no student of science, can thoroughly understand how little some persons know about science, until he has observed how much will be believed, if only published with the apparent authority of a few known names, and announced with a sufficient parade of technical verbiage; nor is it so easy as might be thought, even for those who are acquainted with the facts, to disprove either a hoax or a paradox. Nothing, indeed, can much more thoroughly perplex and confound a student of science than to be asked to prove, for example, that the earth is not flat, or the moon not inhabited by creatures like ourselves; for the circumstance that such a question is asked implies ignorance so thorough of the very facts on which the proof must be based, as to render argument all but hopeless from the outset. I have had a somewhat wide experience of paradoxists, and have noted the experience of De Morgan and others who, like him, have tried to convince them of their folly. The conclusion at which I have arrived is, that to make a rope of sand were an easy task compared with the attempt to instil the simpler facts of science into paradoxical heads.

I would make some remarks, in conclusion, upon scientific or quasi-scientific papers not intended to deceive, but yet presenting imaginary scenes, events, and so forth, described more or less in accordance with scientific facts. Imaginary journeys to the sun, moon, planets, and stars; travels over regions on the earth as yet unexplored; voyages under the sea, through the bowels of the earth, and other such narratives, may, perhaps, be sometimes usefully written and read, so long as certain conditions are fulfilled by the narrator. In the first place, while adopting, to preserve the unities, the tone of one relating facts which actually occurred, he should not suffer even the simplest among his readers to lie under the least misapprehension as to the true nature of the narrative. Again, since of necessity established facts must in such a narrative appear in company with the results of more or less probable surmise, the reader should have some means of distinguishing where fact ends and surmise begins. For example, in a paper I once wrote, entitled 'A Journey to Saturn,' I was not sufficiently careful to note that while the appearances described in the approach towards the planet were in reality based on the observed appearances as higher and higher telescopic powers are applied to the planet, others supposed to have been seen by the visitors to Saturn when actually within his system, were only such as might possibly or probably be seen, but for which we have no real evidence. In consequence of this omission, I received several inquiries about these matters. 'Is it true,' some wrote, 'that the small satellite Hyperion' (scarce discernible in powerful telescopes, while Titan and Japetus on either side are large) 'is only one of a ring of small satellites travelling between the orbits of the larger moons?'—as the same planets travel between the paths of Mars and Jupiter. Others asked on what grounds it was said that the voyagers found small moons circling about Titan, the giant moon of the Saturnian system, as the moons of Jupiter and Saturn circle around those giant members of the solar system. In each case, I was reduced to the abject necessity of explaining that there was no evidence for the alleged state of things, which, however, might nevertheless exist. Scientific fiction which has to be interpreted in that way is as bad as a joke that has to be explained. In my 'Journey to the Sun' I was more successful (it was the earlier essay, however); insomuch that Professor Young, of Dartmouth College (Hanover, N.H.), one of the most skilful solar observers living, assured me that, with scarcely a single exception, the various phenomena described corresponded exactly with the ideas he had formed respecting the probable condition of our luminary.[50]

But I must confess that my own experience has not been, on the whole, favourable to that kind of popular science writing. It appears to me that the more thoroughly the writer of such an essay has studied any particular scientific subject, the less able must he be to write a fictitious narrative respecting it. Just as those ignorant of any subject are often the readiest to theorise about it, because least hampered by exact knowledge, so I think that the careful avoidance of any exact study of the details of a scientific subject must greatly facilitate the writing of a fictitious narrative respecting it. But unfortunately a narrative written under such conditions, however interesting to the general reader, can scarcely forward the propagation of scientific knowledge, one of the qualities claimed for fables of the kind. As an instance in point, I may cite Jules Verne's 'Voyage to the Moon,' where (apart, of course, from the inherent and intentional absurdity of the scheme itself), the circumstances which are described are calculated to give entirely erroneous ideas about the laws of motion. Nothing could be more amusing, but at the same time nothing more scientifically absurd, than the story of the dead dog Satellite, which, flung out of the travelling projectile, becomes a veritable satellite, moving always beside the voyagers; for, with whatever velocity the dog had been expelled by them, with that same velocity would he have retreated continually from their projectile abode, whose own attraction on the dog would have had no appreciable effect in checking his departure. Again, the scene when the projectile reaches the neutral point between the earth and moon, so that there is no longer any gravity to keep the travellers on the floor of their travelling car, is well conceived (though, in part, somewhat profane); but in reality the state of things described as occurring there would have prevailed throughout the journey. The travellers would no more be drawn earthwards (as compared with the projectile itself) than we travellers on the earth are drawn sunwards with reference to the earth. The earth's attracting force on the projectile and on the travellers would be equal all through the journey, not solely when the projectile reached the neutral point; and being equal on both, would not draw them together. It may be argued that the attractions were equal before the projectile set out on its journey, and therefore, if the reasoning just given were correct, the travellers ought not to have had any weight keeping them on the floor of the projectile before it started, 'which is absurd.' But the pressure upon the floor of the projectile at rest is caused by the floor being kept from moving; let it be free to obey gravity, and there will no longer be any pressure: and throughout the journey to the moon, the projectile, like the travellers it contains, is obeying the action of gravity. Unfortunately, those who are able to follow the correct reasoning in such matters are not those to whom Jules Verne's account would suggest wrong ideas about matters dynamical; the young learner who is misled by such narratives is neither able to reason out the matter for himself, nor to understand the true reasoning respecting it. He is, therefore, apt to be set quite at sea by stories of the kind, and especially by the specious reasoning introduced to explain the events described. In fine, it would seem that such narratives must be valued for their intrinsic interest, just like other novels or romances, not for the quality sometimes claimed for them of combining instruction with amusement.

X. ON SOME ASTRONOMICAL PARADOXES.

For many years the late Professor De Morgan contributed to the columns of the 'Athenæum' a series of papers in which he dealt with the strange treatises in which the earth is flattened, the circle squared, the angle divided into three, the cube doubled (the famous problem which the Delphic oracle set astronomers), and the whole of modern astronomy shown to be a delusion and a snare. He treated these works in a quaint fashion: not unkindly, for his was a kindly nature; not even earnestly, though he was thoroughly in earnest; yet in such sort as to rouse the indignation of the unfortunate paradoxists. He was abused roundly for what he said, but much more roundly when he declined further controversy. Paradoxists of the ignorant sort (for it must be remembered that not all are ignorant) are, indeed, well practised in abuse, and have long learned to call mathematicians and astronomers cheats and charlatans. They freely used their vocabulary for the benefit of De Morgan, whom they denounced as a scurrilous scribbler, a defamatory, dishonest, abusive, ungentlemanly, and libellous trickster.

He bore this shower of abuse with exceeding patience and good nature. He had not been wholly unprepared for it, in fact; and, as he had a purpose in dealing with the paradoxists, he was satisfied to continue that quiet analysis of their work which so roused their indignation. He found in them a curious subject of study; and he found an equally curious subject of study in their disciples. The simpler—not to say more foolish—paradoxists, whose wonderful discoveries are merely amazing misapprehensions, were even more interesting to De Morgan than the craftier sort who make a living, or try to make a living, out of their pretended theories. Indeed, these last he treated, as they deserved, with a scathing satire quite different from his humorous and not ungenial comments on the wonderful theories of the honest paradoxists.

There is one special use to which the study of paradox-literature may be applied, which—so far as I know—has not hitherto been much attended to. It may be questioned whether half the strange notions into which paradoxists fall must not be ascribed to the vagueness of too many of our scientific treatises. A half-understood explanation, or a carelessly worded account of some natural phenomenon, leads the paradoxist, whose nature is compounded of conceit and simplicity, to originate a theory of his own on the subject. Once such a theory has been devised, it takes complete possession of the paradoxist's mind. All the facts of which he thenceforward hears, which bear in the least on his favourite craze, appear to give evidence in its favour, even though in reality they are most obviously opposed to it. He learns to look upon himself as an unappreciated Newton, and to see the bitterest malevolence in those who venture to question his preposterous notions. He is fortunate if he do not suffer his theories to withdraw him from his means of earning a livelihood, or if he do not waste his substance in propounding and defending them.

One of the favourite subjects for paradox-forming is the accepted theory of the solar system. Our books on astronomy too often present this theory in such sort that it seems only a successor of Ptolemy's; and the impression is conveyed that, like Ptolemy's, it may be one day superseded by some other theory. This is quite enough for the paradoxist. If a new theory is to replace the one now accepted, why should not he be the new Copernicus? He starts upon the road without a tithe of the knowledge that old Ptolemy possessed, unaware of the difficulties which Ptolemy met and dealt with—free, therefore, because of his perfect ignorance, to form theories at which Ptolemy would have smiled. He has probably heard of the

which disfigured the theories of the ancients; but he is quite unconscious that every one of those scribblings had a real meaning, each being intended to account for some observed peculiarity of planetary motion, which must be accounted for by any theory which is to claim acceptance. In this happy unconsciousness that there are any peculiarities requiring explanation, knowing nothing of the strange paths which the planets are seen to follow on the heavenly vault,

he placidly puts forward—and presently very vehemently urges—a theory which accounts for none of these things.

It has often seemed to me that a large part of the mischief—for let it be remembered that the published errors of the paradoxist are indicative of much unpublished misapprehension—arises from the undeserved contempt with which our books of astronomy too often treat the labours of Ptolemy, Tycho Brahe, and others who advocated erroneous theories. If the simple truth were told, that the theory of Ptolemy was a masterpiece of ingenuity and that it was worked out by his followers in a way which merits the highest possible praise, while the theory of Tycho Brahe was placed in reality on a sounder basis than that of Copernicus, and accounted as well and as simply for observed appearances, the student would begin to realise the noble nature of the problem which those great astronomers dealt with. And again, if stress were laid upon the fact that Tycho Brahe devoted years upon years of his life to secure such observations of the planets as might settle the questions at issue, the student would learn something of the spirit in which the true lover of science proceeds.

It seems to me, also, that far too little is said about the kind of work by which Kepler and Newton finally established the accepted theories. There is a strange charm in the history of those twenty years of Kepler's life during which he was analysing the observations made by Tycho Brahe. Surrounded with domestic trials and anxieties, which might well have claimed his whole attention, tried grievously by ill-health and bodily anguish, he laboured all those years upon erroneous theories. The very worst of these had infinitely more evidence in its favour than the best which the paradoxists have brought forth. There was not one of those theories which nine out of ten of his scientific contemporaries would not have accepted ungrudgingly. Yet he wrought these theories one after another to their own disproof. Nineteen of them he tried and rejected—the twentieth was the true theory of the solar system. Perhaps nothing in the whole history of astronomy affords a nobler lesson to the student of science—unless, indeed, it be the calm philosophy with which Newton for eighteen years suffered the theory of the universe to remain in abeyance, because faulty measurements of the earth prevented his calculations from agreeing with observed facts. But, as Professor Tyndall has well remarked—and the paradoxist should lay the lesson well to heart—'Newton's action in this matter was the normal action of the scientific mind. If it were otherwise—if scientific men were not accustomed to demand verification, if they were satisfied with the imperfect while the perfect is attainable—their science, instead of being, as it is, a fortress of adamant, would be a house of clay, ill fitted to bear the buffetings of the theologic storms to which it has been from time to time, and is at present, exposed.'

The fame of Newton has proved to many paradoxists an irresistible attraction; it has been to these unfortunates as the candle to the fluttering moth. Circle-squaring, as we shall presently see, has had its attractions, nor have earth-fixing and earth-flattening been neglected; but attacking the law of gravitation has been the favourite work of paradoxists. Newton has been praised as surpassing the whole human race in genius; mathematicians and astronomers have agreed to laud him as unequalled; why should not Paradoxus displace him and be praised in like manner? It would be unfair, perhaps, to say that the paradoxist consciously argues thus. He doubtless in most instances convinces himself that he has really detected some flaw in the theory of gravitation. Yet it is impossible not to recognise, as the real motive of every paradox-monger, the desire to have that said of him which has been said of Newton: 'Genus humanum ingenio superavit.'

I remember a curious instance of this which occurred soon after the appearance of the comet of 1858. It chanced that, while that object was under discussion, reference was made to the action of a repulsive force exerted by the sun upon the matter of the comet's tail. On this, some one addressed a long letter to a Glasgow newspaper, announcing that he had long ago proved that the sun's attraction alone is insufficient to account for the planetary motions. His reasoning was amazingly simple. If the sun's attraction is powerful enough to keep the outer planets in their course, it must be too powerful for Venus and Mercury close by the sun; if it only just suffices to keep these in their course, it cannot possibly be powerful enough to restrain the outer planets. The writer of this letter said that he had been very badly treated by scientific bodies. He had announced his discovery to the Royal Astronomical Society, the Royal Society, the Imperial Academy at Paris, and other scientific bodies; but they had one and all refused to listen to him. He had forsaken or neglected his trade for several years in order to give attention to the new and (as he thought) the true theory of the universe. He complained in a specially bitter manner of the unfavourable comments which men of science had made upon his views in private letters addressed to him in reply to his communications.

There is something melancholy even in what is most ridiculous in cases of this sort. The simplicity which supposes that considerations so obvious as those adduced could escape the scrutiny, not of Newton only, but of all who have followed in the same track during two centuries, is certainly stupendous; nor can one fail to smile at seeing a difficulty, such as might naturally suggest itself to a beginner, and such as half-a-dozen words from an expert would clear up, regarded gravely as a discovery calculated to make its author famous for all time. Yet, when one considers the probable consequences of the blunder to the unhappy enthusiast, and perchance to his family, it is difficult not to feel a sense of pity, quite apart from that pity allied to contempt which is excited by his mistake. A few words added to the account of Newton's theory, which the paradoxist had probably read in some astronomical treatise, would have prevented all this mischief. Indeed, this difficulty, which, as we have said, is a natural one, should be dealt with and removed in any account of the planetary system intended for beginners. The simple statement that the outer planets move more slowly than the inner, and so require a smaller force to keep them in their course, would have sufficed, not, perhaps, altogether to remove the difficulty, but to show the beginner where the explanation was to be looked for.