The Moon-Voyage

CHAPTER VI.

WHAT IT IS IM­POS­SI­BLE TO IG­NORE AND WHAT IS NO LONGER AL­LOWED TO BE BE­LIEVED IN THE UNIT­ED STATES.

The im­me­di­ate ef­fect of Bar­bi­cane's propo­si­tion was that of bring­ing out all as­tro­nom­ical facts rel­ative to the Queen of Night. Ev­ery­body be­gan to study her as­sid­uous­ly. It seemed as if the moon had ap­peared on the hori­zon for the first time, and that no one had ev­er seen her in the sky be­fore. She be­came the fash­ion; she was the li­on of the day, with­out ap­pear­ing less mod­est on that ac­count, and took her place amongst the “stars” with­out be­ing any the proud­er. The news­pa­pers re­vived old anec­dotes in which this “Sun of the wolves” played a part; they re­called the in­flu­ence which the ig­no­rance of past ages had as­cribed to her; they sang about her in ev­ery tone; a lit­tle more and they would have quot­ed her wit­ty say­ings; the whole of Amer­ica was filled with se­leno­ma­nia.

The sci­en­tif­ic jour­nals treat­ed the ques­tion which touched up­on the en­ter­prise of the Gun Club more spe­cial­ly; they pub­lished the let­ter from the Ob­ser­va­to­ry of Cam­bridge, they com­ment­ed up­on it and ap­proved of it with­out re­serve.

In short, even the most ig­no­rant Yan­kee was no longer al­lowed to be ig­no­rant of a sin­gle fact rel­ative to his satel­lite, nor, to the old­est wom­en amongst them, to have any su­per­sti­tions about her left. Sci­ence flood­ed them; it pen­etrat­ed in­to their eyes and ears; it was im­pos­si­ble to be an ass--in as­tron­omy.

Un­til then many peo­ple did not know how the dis­tance be­tween the earth and the moon had been cal­cu­lat­ed. This fact was tak­en ad­van­tage of to ex­plain 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 the an­gle formed by two straight lines drawn from ei­ther ex­trem­ity of the earth's ra­dius to the moon. If they were in doubt about the per­fec­tion of this method, it was im­me­di­ate­ly proved to them that not on­ly was the mean dis­tance 234,347 miles, but that as­tronomers were right to with­in sev­en­ty miles.

To those who were not fa­mil­iar with the move­ments of the moon, the news­pa­pers demon­strat­ed dai­ly that she pos­sess­es two dis­tinct move­ments, the first be­ing that of ro­ta­tion up­on her ax­is, the sec­ond that of rev­olu­tion round the earth, ac­com­plish­ing both in the same time--that is to say, in 27-1/3 days.

The move­ment of ro­ta­tion is the one that caus­es night and day on the sur­face of the moon, on­ly there is but one day and one night in a lu­nar month, and they each last 354-1/3 hours. But, hap­pi­ly, the face, turned to­wards the ter­res­tri­al globe, is light­ed by it with an in­ten­si­ty equal to the light of four­teen moons. As to the oth­er face, the one al­ways in­vis­ible, it has nat­ural­ly 354 hours of ab­so­lute night, tem­pered on­ly by “the pale light that falls from the stars.” This phe­nomenon is due sole­ly to the pe­cu­liar­ity that the move­ments of ro­ta­tion and rev­olu­tion are ac­com­plished in rig­or­ous­ly equal pe­ri­ods, a phe­nomenon which, ac­cord­ing to Cassi­ni and Her­schel, is com­mon to the satel­lites of Jupiter, and, very prob­ably to the oth­er satel­lites.

Some well-​dis­posed but rather un­yield­ing minds did not quite un­der­stand at first how, if the moon in­vari­ably shows the same face to the earth dur­ing her rev­olu­tion, she de­scribes one turn round her­self in the same pe­ri­od of time. To such it was an­swered--“Go in­to your din­ing-​room, and turn round the ta­ble so as al­ways to keep your face to­wards the cen­tre; when your cir­cu­lar walk is end­ed you will have de­scribed one cir­cle round your­selves, since your eye will have suc­ces­sive­ly tra­versed ev­ery point of the room. Well, then, the room is the heav­ens, the ta­ble is the earth, 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 cer­tain fluc­tu­ations from north to south and from west to east, called li­bra­tion, she shows rather more than the half of her disc, about 0.57.

When the ig­no­ra­mus­es knew as much as the di­rec­tor of the Cam­bridge Ob­ser­va­to­ry about the moon's move­ment of ro­ta­tion they be­gan to make them­selves un­easy about her move­ment of rev­olu­tion round the earth, and twen­ty sci­en­tif­ic re­views quick­ly gave them the in­for­ma­tion they want­ed. They then learnt that the fir­ma­ment, with its in­fi­nite stars, may be looked up­on as a vast di­al up­on which the moon moves, in­di­cat­ing the time to all the in­hab­itants of the earth; that it is in this move­ment that the Queen of Night shows her­self in her dif­fer­ent phas­es, that she is full when she is in op­po­si­tion with the sun--that is to say, when the three bod­ies are on a line with each oth­er, the earth be­ing in the cen­tre; that the moon is new when she is in con­junc­tion with the sun--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 the sun and the earth, a right an­gle of which she oc­cu­pies the apex.

Some per­spi­ca­cious Yan­kees in­ferred in con­se­quence that eclipses could on­ly take place at the pe­ri­ods of con­junc­tion or op­po­si­tion, and their rea­son­ing was just. In con­junc­tion the moon can eclipse the sun, whilst in op­po­si­tion it is the earth that can eclipse him in her turn; and the rea­son these eclipses do not hap­pen twice in a lu­nar month is be­cause the plane up­on which the moon moves is el­lip­ti­cal like that of the earth.

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 be said about it. Ev­ery one knew that this height varies ac­cord­ing to the lat­itude of the place where the ob­ser­va­tion is tak­en. But the on­ly zones of the globe where the moon reach­es her zenith--that is to say, where she is di­rect­ly above the heads of the spec­ta­tors--are nec­es­sar­ily com­prised be­tween the 28th par­al­lels and the equa­tor. Hence the im­por­tant rec­om­men­da­tion giv­en to at­tempt the ex­per­iment up­on some point in this part of the globe, in or­der that the pro­jec­tile may be hurled per­pen­dic­ular­ly, and may thus more quick­ly es­cape the at­trac­tion of grav­ita­tion. This was a con­di­tion es­sen­tial to the suc­cess of the en­ter­prise, 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 that it is an el­lipse of which the earth oc­cu­pies one of the fo­ci. These el­lip­ti­cal or­bits are com­mon to all the plan­ets as well as to all the satel­lites, and ra­tio­nal mech­anism rig­or­ous­ly proves that it could not be oth­er­wise. It was clear­ly un­der­stood that when at her apogee the moon was far­thest from the earth, and when at her perigee she was near­est to our plan­et.

This, there­fore, was what ev­ery Amer­ican knew whether he wished to or no, and what no one could de­cent­ly be ig­no­rant of. But if these true prin­ci­ples rapid­ly made their way, cer­tain il­lu­sive fears and many er­rors were with dif­fi­cul­ty cleared away.

Some wor­thy peo­ple main­tained, for in­stance, that the moon was an an­cient comet, which, whilst trav­el­ling along its elon­gat­ed or­bit round the sun, passed near to the earth, and was re­tained in her cir­cle of at­trac­tion. The draw­ing-​room as­tronomers pre­tend­ed to ex­plain thus the burnt as­pect of the moon, a mis­for­tune of which they ac­cused the sun. On­ly when they were told to no­tice that comets have an at­mo­sphere, and that the moon has lit­tle or none, they did not know what to an­swer.

Oth­ers be­long­ing to the class of “Shak­ers” man­ifest­ed cer­tain fears about the moon; they had heard that since the ob­ser­va­tions made in the times of the Caliphs her move­ment of rev­olu­tion had ac­cel­er­at­ed in a cer­tain pro­por­tion; they thence very log­ical­ly con­clud­ed that an ac­cel­er­ation of move­ment must cor­re­spond to a diminu­tion in the dis­tance be­tween the two bod­ies, and that this dou­ble ef­fect go­ing on in­finite­ly the moon would one day end by falling in­to the earth. How­ev­er, they were obliged to re­as­sure them­selves and cease to fear for fu­ture gen­er­ations when they were told that ac­cord­ing to the cal­cu­la­tions of Laplace, an il­lus­tri­ous French math­emati­cian, this ac­cel­er­ation of move­ment was re­strict­ed with­in very nar­row lim­its, and that a pro­por­tion­al diminu­tion will fol­low it. Thus the equi­lib­ri­um of the so­lar world can­not be dis­turbed in fu­ture cen­turies.

Last­ly there was the su­per­sti­tious class of ig­no­ra­mus­es to be dealt with; these are not con­tent with be­ing ig­no­rant; they know what does not ex­ist, and about the moon they know a great deal. Some of them con­sid­ered her disc to be a pol­ished mir­ror by means of which peo­ple might see them­selves from dif­fer­ent points on the earth, and com­mu­ni­cate their thoughts to one an­oth­er. Oth­ers pre­tend­ed that out of 1,000 new moons 950 had brought some no­table change, such as cat­aclysms, rev­olu­tions, earth­quakes, del­uges, &c.; they there­fore be­lieved in the mys­te­ri­ous in­flu­ence of the Queen of Night on hu­man des­tinies; they think that ev­ery Se­len­ite is con­nect­ed by some sym­pa­thet­ic tie with each in­hab­itant of the earth; they pre­tend, with Dr. Mead, that she en­tire­ly gov­erns the vi­tal sys­tem--that boys are born dur­ing the new moon and girls dur­ing her last quar­ter, &c., &c. But at last it be­came nec­es­sary to 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 cour­te­sans of ev­ery pow­er, if some turned their backs on her, the im­mense ma­jor­ity were in her favour. As to the Yan­kees, they had no oth­er am­bi­tion than that of tak­ing pos­ses­sion of this new con­ti­nent of the sky, and to plant up­on its high­est sum­mit the star-​span­gled ban­ner of the Unit­ed States of Amer­ica.