CHAPTER VI.
WHAT IT IS IMPOSSIBLE TO IGNORE AND WHAT IS NO LONGER ALLOWED TO BEBELIEVED IN THE UNITED STATES.
The immediate effect of Barbicane's proposition was that of bringing outall astronomical facts relative to the Queen of Night. Everybody beganto study her assiduously. It seemed as if the moon had appeared on thehorizon for the first time, and that no one had ever seen her in the skybefore. She became the fashion; she was the lion of the day, withoutappearing less modest on that account, and took her place amongst the"stars" without being any the prouder. The newspapers revived oldanecdotes in which this "Sun of the wolves" played a part; they recalledthe influence which the ignorance of past ages had ascribed to her; theysang about her in every tone; a little more and they would have quotedher witty sayings; the whole of America was filled with selenomania.
The scientific journals treated the question which touched upon theenterprise of the Gun Club more specially; they published the letterfrom the Observatory of Cambridge, they commented upon it and approvedof it without reserve.
In short, even the most ignorant Yankee was no longer allowed to beignorant of a single fact relative to his satellite, nor, to the oldestwomen amongst them, to have any superstitions about her left. Scienceflooded them; it penetrated into their eyes and ears; it was impossibleto be an ass--in astronomy.
Until then many people did not know how the distance between the earthand the moon had been calculated. This fact was taken advantage of toexplain to them that it was done by measuring the parallax of the moon.If the word "parallax" seemed new to them, they were told it was theangle formed by two straight lines drawn from either extremity of theearth's radius to the moon. If they were in doubt about the perfectionof this method, it was immediately proved to them that not only was themean distance 234,347 miles, but that astronomers were right to withinseventy miles.
To those who were not familiar with the movements of the moon, thenewspapers demonstrated daily that she possesses two distinct movements,the first being that of rotation upon her axis, the second that ofrevolution round the earth, accomplishing both in the same time--that isto say, in 27-1/3 days.
The movement of rotation is the one that causes night and day on thesurface of the moon, only there is but one day and one night in a lunarmonth, and they each last 354-1/3 hours. But, happily, the face, turnedtowards the terrestrial globe, is lighted by it with an intensity equalto the light of fourteen moons. As to the other face, the one alwaysinvisible, it has naturally 354 hours of absolute night, tempered onlyby "the pale light that falls from the stars." This phenomenon is duesolely to the peculiarity that the movements of rotation and revolutionare accomplished in rigorously equal periods, a phenomenon which,according to Cassini and Herschel, is common to the satellites ofJupiter, and, very probably to the other satellites.
Some well-disposed but rather unyielding minds did not quite understandat first how, if the moon invariably shows the same face to the earthduring her revolution, she describes one turn round herself in the sameperiod of time. To such it was answered--"Go into your dining-room, andturn round the table so as always to keep your face towards the centre;when your circular walk is ended you will have described one circleround yourselves, since your eye will have successively traversed everypoint of the room. Well, then, the room is the heavens, the table is theearth, and you are the moon!"
And they go away delighted with the comparison.
Thus, then, the moon always presents the same face to the earth; still,to be quite exact, it should be added that in consequence of certainfluctuations from north to south and from west to east, calledlibration, she shows rather more than the half of her disc, about 0.57.
When the ignoramuses knew as much as the director of the CambridgeObservatory about the moon's movement of rotation they began to makethemselves uneasy about her movement of revolution round the earth, andtwenty scientific reviews quickly gave them the information they wanted.They then learnt that the firmament, with its infinite stars, may belooked upon as a vast dial upon which the moon moves, indicating thetime to all the inhabitants of the earth; that it is in this movementthat the Queen of Night shows herself in her different phases, that sheis full when she is in opposition with the sun--that is to say, when thethree bodies are on a line with each other, the earth being in thecentre; that the moon is new when she is in conjunction with thesun--that is to say, when she is between the sun and the earth; lastly,that the moon is in her first or last quarter when she makes, with thesun and the earth, a right angle of which she occupies the apex.
Some perspicacious Yankees inferred in consequence that eclipses couldonly take place at the periods of conjunction or opposition, and theirreasoning was just. In conjunction the moon can eclipse the sun, whilstin opposition it is the earth that can eclipse him in her turn; and thereason these eclipses do not happen twice in a lunar month is becausethe plane upon which the moon moves is elliptical like that of theearth.
As to the height which the Queen of Night can attain above the horizon,the letter from the Observatory of Cambridge contained all that can besaid about it. Every one knew that this height varies according to thelatitude of the place where the observation is taken. But the only zonesof the globe where the moon reaches her zenith--that is to say, whereshe is directly above the heads of the spectators--are necessarilycomprised between the 28th parallels and the equator. Hence theimportant recommendation given to attempt the experiment upon some pointin this part of the globe, in order that the projectile may be hurledperpendicularly, and may thus more quickly escape the attraction ofgravitation. This was a condition essential to the success of theenterprise, and public opinion was much exercised thereupon.
As to the line followed by the moon in her revolution round the earth,the Observatory of Cambridge had demonstrated to the most ignorant thatit is an ellipse of which the earth occupies one of the foci. Theseelliptical orbits are common to all the planets as well as to all thesatellites, and rational mechanism rigorously proves that it could notbe otherwise. It was clearly understood that when at her apogee the moonwas farthest from the earth, and when at her perigee she was nearest toour planet.
This, therefore, was what every American knew whether he wished to orno, and what no one could decently be ignorant of. But if these trueprinciples rapidly made their way, certain illusive fears and manyerrors were with difficulty cleared away.
Some worthy people maintained, for instance, that the moon was anancient comet, which, whilst travelling along its elongated orbit roundthe sun, passed near to the earth, and was retained in her circle ofattraction. The drawing-room astronomers pretended to explain thus theburnt aspect of the moon, a misfortune of which they accused the sun.Only when they were told to notice that comets have an atmosphere, andthat the moon has little or none, they did not know what to answer.
Others belonging to the class of "Shakers" manifested certain fearsabout the moon; they had heard that since the observations made in thetimes of the Caliphs her movement of revolution had accelerated in acertain proportion; they thence very logically concluded that anacceleration of movement must correspond to a diminution in the distancebetween the two bodies, and that this double effect going on infinitelythe moon would one day end by falling into the earth. However, they wereobliged to reassure themselves and cease to fear for future generationswhen they were told that according to the calculations of Laplace, anillustrious French mathematician, this acceleration of movement wasrestricted within very narrow limits, and that a proportional diminutionwill follow it. Thus the equilibrium of the solar world cannot bedisturbed in future centuries.
Lastly there was the superstitious class of ignoramuses to be dealtwith; these are not content with being ignorant; they know what does notexist, and about the moon they know a great deal. Some of themconsidered her disc to be a polished mirror by means of which peoplemight see themselves from different points on the earth, and communicatetheir thoughts to one another. Others pretended that out of 1,000 ne
wmoons 950 had brought some notable change, such as cataclysms,revolutions, earthquakes, deluges, &c.; they therefore believed in themysterious influence of the Queen of Night on human destinies; theythink that every Selenite is connected by some sympathetic tie with eachinhabitant of the earth; they pretend, with Dr. Mead, that she entirelygoverns the vital system--that boys are born during the new moon andgirls during her last quarter, &c., &c. But at last it became necessaryto give up these vulgar errors, to come back to truth; and if the moon,stripped of her influence, lost her prestige in the minds of courtesansof every power, if some turned their backs on her, the immense majoritywere in her favour. As to the Yankees, they had no other ambition thanthat of taking possession of this new continent of the sky, and to plantupon its highest summit the star-spangled banner of the United States ofAmerica.