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 s.p.a.ce 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 a.s.sert 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 ma.s.s; and, as great cornets are probably followed by many such ma.s.ses, it seems reasonable to infer that if such a comet fell upon the sun, his surface being pelted with such exceptionally large ma.s.ses, stoned with these mighty meteoric b.a.l.l.s, 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-gla.s.s 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, surpa.s.sing ordinary sunlight in the same degree that ordinary sunlight surpa.s.sed 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 a.s.suming 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 s.p.a.ce, 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 s.p.a.ce, 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 l.u.s.tre, 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 a.n.a.lysis, 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 s.p.a.ce. 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 s.p.a.ces. 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 superst.i.tions 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 superst.i.tion which had ruled over men"s minds for thousands of years.
No sect had been free from this superst.i.tion. 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 ma.s.ses 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 superst.i.tious than usual; for misery brings out the superst.i.tions--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 superst.i.tions 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 pa.s.s 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 s.e.x, whom I could almost call old women too, remarked that those two comets pa.s.sed 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 pa.s.s 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 G.o.d"s judgments, and especially when, the Plague having followed the first, I yet saw another of the same kind, I could not but say, G.o.d 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 superst.i.tion might a.s.sign 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 superst.i.tion, 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 ent.i.tled "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 advertis.e.m.e.nt:--"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 a.s.sign 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:--
"Gren.o.ble, 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 a.s.sured us that in truth its perruque would signify nothing mischievous, but that its tail would be an infallible sign of the wrath of heaven. If James Bernouilli mistook, it is, after all, but a matter of fifty-four years and three days.
"Now, so small an error as this being regarded by all geometricians as of little moment in the immensity of ages, it is manifest that nothing can be more reasonable than to hope (_sic, esperer_) for the end of the world on the 20th of this present month of May 1773, or in some other year. If the thing should not come to pa.s.s, "omittance is no quittance"
(_ce qui est differe, n"est pas perdu_).
"There is certainly no reason for laughing at M. Trissotin, triple idiot though he is (_tout Trissotin qu"il est_), when he says to Madame Philaminte (Moliere"s "Femmes Savantes," acte iv. scene 3),
"Nous l"avons en dormant, madame, echappe belle; Un monde pres de nous a pa.s.se tout du long, Est chu tout au travers de notre tourbillon; Et, s"il eut en chemin rencontre notre terre, Elle eut ete brisee en morceaux comme verre.
"A comet coursing along its parabolic orbit may come full tilt against our earth. But then, what will happen? Either that comet will have a force equal to that of our earth, or greater, or less. If equal, we shall do the comet as much harm as it will do us, action and reaction being equal; if greater, the comet will bear us away with it; if less, we shall bear away the comet.
"This great event may occur in a thousand ways, and no one can affirm that our earth and the other planets have not experienced more than one revolution, through the mischance of encountering a comet on their path.
"The Parisians will not desert their city on the 20th inst.; they will sing songs, and the play of "The Comet and the World"s End" will be performed at the Opera Comique."
The last touch is as fine in its way as Sydney Smith"s remark that, if London were destroyed by an earthquake, the surviving citizens would celebrate the event by a public dinner among the ruins. Voltaire"s prediction was not fulfilled exactly to the letter, but what actually happened was even funnier than what his lively imagination had suggested. It was stated by a Parisian Professor in 1832 (as a reason why the Academy of Sciences should refute an a.s.sertion 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 circ.u.mstances. 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-gla.s.s 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 circ.u.mstance 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 s.p.a.ce. 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 G.o.d"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 fict.i.tious 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 pa.s.sages 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 pa.s.sage 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.
Pa.s.sing 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, acc.u.mulating 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 a.n.a.logy, or to the severe tradition that the moon is tenanted only by the h.o.a.ry _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) pa.s.sages in the pamphlet. "About three years ago, in the course of a conversational discussion with Sir David Brewster upon the merits of some ingenious suggestions by the latter, in his article on Optics in the "Edinburgh Encyclopaedia," p. 644, for improvements in Newtonian reflectors, Sir John Herschel adverted to the convenient simplicity of the old astronomical telescopes that were without tubes, and the object-gla.s.s 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 circ.u.mstances; 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 antic.i.p.ated the other in presenting the prompt ill.u.s.tration that if the rays of the hydro-oxygen microscope, pa.s.sed through a drop of water containing the larvae of a gnat and other objects invisible to the naked eye, rendered them not only keenly but firmly magnified to dimensions of many feet; so could the same artificial light, pa.s.sed 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-gla.s.s. 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 pa.s.sage of rays (which originally came from the object whose image they form) through a certain small s.p.a.ce, to send _other_ rays (coming from some other luminous object) through the same small s.p.a.ce, 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 (subst.i.tuting two or three straight rods to hold the gla.s.s 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-gla.s.s (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 Suss.e.x, 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, navely 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-gla.s.s, 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-gla.s.s. 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 circ.u.mstances, that it was essential to follow the facts as closely as possible. Of course, also, some explanation had to be given of the circ.u.mstance 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 acc.u.mulated 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 ma.s.s first presented; but in a few seconds a shelving pile appeared, of five or six columns" width, which showed their figure to be hexagonal, and their articulations similar to those of the basaltic formation at Staffa. This precipitous cliff was profusely covered with a dark red flower, precisely similar, says Dr.
Grant, to the Papaver Rhoeus, or Rose Poppy, of our sublunary cornfields; and this was the first organic production of nature in a foreign world ever revealed to the eyes of men."
It would be wearisome to go through the whole series of observations thus fabled, and only a few of the more striking features need be indicated. The discoveries are carefully graduated in interest. Thus we have seen how, after recognising basaltic formations, the observers discovered flowers: they next see a lunar forest, whose "trees were of one unvaried kind, and unlike any on earth except the largest kind of yews in the English churchyards." (There is an American ring in this sentence, by the way, as there is in one, a few lines farther on, where the narrator having stated that by mistake the observers had the Sea of Clouds instead of a more easterly spot in the field of view, proceeds to say: "However, the moon was a free country, and we not as yet attached to any particular province.") Next a lunar ocean is described, "the water nearly as blue as that of the deep sea, and breaking in large white billows upon the strand, while the action of very high tides was quite manifest upon the face of the cliffs for more than a hundred miles." After a description of several valleys, hills, mountains and forests, we come to the discovery of animal life. An oval valley surrounded by hills, red as the purest vermilion, is selected as the scene. "Small collections of trees, of every imaginable kind, were scattered about the whole of this luxuriant area; and here our magnifiers blessed our panting hopes with specimens of conscious existence. In the shade of the woods we beheld brown quadrupeds having all the external characteristics of the bison, but more diminutive than any species of the bos genus in our natural history." Then herds of agile creatures like antelopes are described, "abounding on the acclivitous glades of the woods." In the contemplation of these sprightly animals the narrator becomes quite lively. "This beautiful creature," says he, "afforded us the most exquisite amus.e.m.e.nt. 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 circ.u.mstances, 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 dest.i.tution 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.