All Around the Moon

  CHAPTER XII.

  A BIRD'S EYE VIEW OF THE LUNAR MOUNTAINS.

  I am rather inclined to believe myself that not one word of Ardan'srhapsody had been ever heard by Barbican or M'Nicholl. Long before hehad spoken his last words, they had once more become mute as statues,and now were both eagerly watching, pencil in hand, spyglass to eye, thenorthern lunar hemisphere towards which they were rapidly but indirectlyapproaching. They had fully made up their minds by this time that theywere leaving far behind them the central point which they would haveprobably reached half an hour ago if they had not been shunted off theircourse by that inopportune bolide.

  About half past twelve o'clock, Barbican broke the dead silence bysaying that after a careful calculation they were now only about 875miles from the Moon's surface, a distance two hundred miles less inlength than the lunar radius, and which was still to be diminished asthey advanced further north. They were at that moment ten degrees northof the equator, almost directly over the ridge lying between the _MareSerenitatis_ and the _Mare Tranquillitatis_. From this latitude all theway up to the north pole the travellers enjoyed a most satisfactory viewof the Moon in all directions and under the most favorable conditions.By means of their spyglasses, magnifying a hundred times, they cut downthis distance of 875 miles to about 9. The great telescope of the RockyMountains, by its enormous magnifying power of 48,000, brought the Moon,it is true, within a distance of 5 miles, or nearly twice as near; butthis advantage of nearness was considerably more than counterbalanced bya want of clearness, resulting from the haziness and refractiveness ofthe terrestrial atmosphere, not to mention those fatal defects in thereflector that the art of man has not yet succeeded in remedying.Accordingly, our travellers, armed with excellent telescopes--of justpower enough to be no injury to clearness,--and posted on unequalledvantage ground, began already to distinguish certain details that hadprobably never been noticed before by terrestrial observers. Even Ardan,by this time quite recovered from his fit of sentiment and probablyinfected a little by the scientific enthusiasm of his companions, beganto observe and note and observe and note, alternately, with all the_sangfroid_ of a veteran astronomer.

  "Friends," said Barbican, again interrupting a silence that had lastedperhaps ten minutes, "whither we are going I can't say; if we shall everrevisit the Earth, I can't tell. Still, it is our duty so to act in allrespects as if these labors of ours were one day to be of service to ourfellow-creatures. Let us keep our souls free from every distraction. Weare now astronomers. We see now what no mortal eye has ever gazed onbefore. This Projectile is simply a work room of the great CambridgeObservatory lifted into space. Let us take observations!"

  With these words, he set to work with a renewed ardor, in which hiscompanions fully participated. The consequence was that they soon hadseveral of the outline maps covered with the best sketches they couldmake of the Moon's various aspects thus presented under such favorablecircumstances. They could now remark not only that they were passing thetenth degree of north latitude, but that the Projectile followed almostdirectly the twentieth degree of east longitude.

  "One thing always puzzled me when examining maps of the Moon," observedArdan, "and I can't say that I see it yet as clearly as if I had thoughtover the matter. It is this. I could understand, when looking through alens at an object, why we get only its reversed image--a simple law ofoptics explains _that_. Therefore, in a map of the Moon, as the bottommeans the north and the top the south, why does not the right mean thewest and the left the east? I suppose I could have made this out by alittle thought, but thinking, that is reflection, not being my forte, itis the last thing I ever care to do. Barbican, throw me a word or two onthe subject."

  "I can see what troubles you," answered Barbican, "but I can also seethat one moment's reflection would have put an end to your perplexity.On ordinary maps of the Earth's surface when the north is the top, theright hand must be the east, the left hand the west, and so on. That issimply because we look _down_ from _above_. And such a map seen througha lens will appear reversed in all respects. But in looking at the Moon,that is _up_ from _down_, we change our position so far that our righthand points west and our left east. Consequently, in our reversed map,though the north becomes south, the right remains east, and--"

  "Enough said! I see it at a glance! Thank you, Barbican. Why did notthey make you a professor of astronomy? Your hint will save me a worldof trouble."[C]

  Aided by the _Mappa Selenographica_, the travellers could easilyrecognize the different portions of the Moon over which they were nowmoving. An occasional glance at our reduction of this map, given as afrontispiece, will enable the gentle reader to follow the travellers onthe line in which they moved and to understand the remarks andobservations in which they occasionally indulged.

  "Where are we now?" asked Ardan.

  "Over the northern shores of the _Mare Nubium_," replied Barbican. "Butwe are still too far off to see with any certainty what they are like.What is the _Mare_ itself? A sea, according to the early astronomers? aplain of solid sand, according to later authority? or an immense forest,according to De la Rue of London, so far the Moon's most successfulphotographer? This gentleman's authority, Ardan, would have given youdecided support in your famous dispute with the Captain at the meetingnear Tampa, for he says very decidedly that the Moon has an atmosphere,very low to be sure but very dense. This, however, we must find out forourselves; and in the meantime let us affirm nothing until we have goodgrounds for positive assertion."

  _Mare Nubium_, though not very clearly outlined on the maps, is easilyrecognized by lying directly east of the regions about the centre. Itwould appear as if this vast plain were sprinkled with immense lavablocks shot forth from the great volcanoes on the right, _Ptolemaeus_,_Alphonse_, _Alpetragius_ and _Arzachel_. But the Projectile advanced sorapidly that these mountains soon disappeared, and the travellers werenot long before they could distinguish the great peaks that closed the"Sea" on its northern boundary. Here a radiating mountain showed asummit so dazzling with the reflection of the solar rays that Ardancould not help crying out:

  "It looks like one of the carbon points of an electric light projectedon a screen! What do you call it, Barbican?"

  "_Copernicus_," replied the President. "Let us examine old_Copernicus_!"

  This grand crater is deservedly considered one of the greatest of thelunar wonders. It lifts its giant ramparts to upwards of 12,000 feetabove the level of the lunar surface. Being quite visible from the Earthand well situated for observation, it is a favorite object forastronomical study; this is particularly the case during the phaseexisting between Last Quarter and the New Moon, when its vast shadows,projected boldly from the east towards the west, allow its prodigiousdimensions to be measured.

  After _Tycho_, which is situated in the southern hemisphere,_Copernicus_ forms the most important radiating mountain in the lunardisc. It looms up, single and isolated, like a gigantic light-house, onthe peninsula separating _Mare Nubium_ from _Oceanus Procellarum_ on oneside and from _Mare Imbrium_ on the other; thus illuminating with itssplendid radiation three "Seas" at a time. The wonderful complexity ofits bright streaks diverging on all sides from its centre presented ascene alike splendid and unique. These streaks, the travellers thought,could be traced further north than in any other direction: they fanciedthey could detect them even in the _Mare Imbrium_, but this of coursemight be owing to the point from which they made their observations. Atone o'clock in the morning, the Projectile, flying through space, wasexactly over this magnificent mountain.

  In spite of the brilliant sunlight that was blazing around them, thetravellers could easily recognize the peculiar features of _Copernicus_.It belongs to those ring mountains of the first class called Circuses.Like _Kepler_ and _Aristarchus_, who rule over _Oceanus Procellarum_,_Copernicus_, when viewed through our telescopes, sometimes glistens sobrightly through the ashy light of the Moon that it has been frequentlytaken for a volcano in full activity. Whatever it may have been once,ho
wever, it is certainly nothing more now than, like all the othermountains on the visible side of the Moon, an extinct volcano, only witha crater of such exceeding grandeur and sublimity as to throw utterlyinto the shade everything like it on our Earth. The crater of Etna is atmost little more than a mile across. The crater of _Copernicus_ has adiameter of at least 50 miles. Within it, the travellers could easilydiscover by their glasses an immense number of terraced ridges, probablylandslips, alternating with stratifications resulting from successiveeruptions. Here and there, but particularly in the southern side, theycaught glimpses of shadows of such intense blackness, projected acrossthe plateau and lying there like pitch spots, that they could not tellthem from yawning chasms of incalculable depth. Outside the crater theshadows were almost as deep, whilst on the plains all around,particularly in the west, so many small craters could be detected thatthe eye in vain attempted to count them.

  "Many circular mountains of this kind," observed Barbican, "can be seenon the lunar surface, but _Copernicus_, though not one of the greatest,is one of the most remarkable on account of those diverging streaks ofbright light that you see radiating from its summit. By lookingsteadily into its crater, you can see more cones than mortal eye everlit on before. They are so numerous as to render the interior plateauquite rugged, and were formerly so many openings giving vent to fire andvolcanic matter. A curious and very common arrangement of this internalplateau of lunar craters is its lying at a lower level than the externalplains, quite the contrary to a terrestrial crater, which generally hasits bottom much higher than the level of the surrounding country. Itfollows therefore that the deep lying curve of the bottom of these ringmountains would give a sphere with a diameter somewhat smaller than theMoon's."

  "What can be the cause of this peculiarity?" asked M'Nicholl.

  "I can't tell;" answered Barbican, "but, as a conjecture, I should saythat it is probably to the comparatively smaller area of the Moon andthe more violent character of her volcanic action that the extremelyrugged character of her surface is mainly due."

  "Why, it's the _Campi Phlegraei_ or the Fire Fields of Naples overagain!" cried Ardan suddenly. "There's _Monte Barbaro_, there's the_Solfatara_, there is the crater of _Astroni_, and there is the _MonteNuovo_, as plain as the hand on my body!"

  "The great resemblance between the region you speak of and the generalsurface of the Moon has been often remarked;" observed Barbican, "butit is even still more striking in the neighborhood of _Theophilus_ onthe borders of _Mare Nectaris_."

  "That's _Mare Nectaris_, the gray spot over there on the southwest,isn't it?" asked M'Nicholl; "is there any likelihood of our getting abetter view of it?"

  "Not the slightest," answered Barbican, "unless we go round the Moon andreturn this way, like a satellite describing its orbit."

  By this time they had arrived at a point vertical to the mountaincentre. _Copernicus's_ vast ramparts formed a perfect circle or rather apair of concentric circles. All around the mountain extended a darkgrayish plain of savage aspect, on which the peak shadows projectedthemselves in sharp relief. In the gloomy bottom of the crater, whosedimensions are vast enough to swallow Mont Blanc body and bones, couldbe distinguished a magnificent group of cones, at least half a mile inheight and glittering like piles of crystal. Towards the north severalbreaches could be seen in the ramparts, due probably to a caving in ofimmense masses accumulated on the summit of the precipitous walls.

  As already observed, the surrounding plains were dotted with numberlesscraters mostly of small dimensions, except _Gay Lussac_ on the north,whose crater was about 12 miles in diameter. Towards the southwest andthe immediate east, the plain appeared to be very flat, no protuberance,no prominence of any kind lifting itself above the general dead level.Towards the north, on the contrary, as far as where the peninsulajutted on _Oceanus Procellarum_, the plain looked like a sea of lavawildly lashed for a while by a furious hurricane and then, when itswaves and breakers and driving ridges were at their wildest, suddenlyfrozen into solidity. Over this rugged, rumpled, wrinkled surface and inall directions, ran the wonderful streaks whose radiating point appearedto be the summit of _Copernicus_. Many of them appeared to be ten mileswide and hundreds of miles in length.

  The travellers disputed for some time on the origin of these strangeradii, but could hardly be said to have arrived at any conclusion moresatisfactory than that already reached by some terrestrial observers.

  To M'Nicholl's question:

  "Why can't these streaks be simply prolonged mountain crests reflectingthe sun's rays more vividly by their superior altitude and comparativesmoothness?"

  Barbican readily replied:

  "These streaks _can't_ be mountain crests, because, if they were, undercertain conditions of solar illumination they should project_shadows_--a thing which they have never been known to do under anycircumstances whatever. In fact, it is only during the period of thefull Moon that these streaks are seen at all; as soon as the sun's raysbecome oblique, they disappear altogether--a proof that their appearanceis due altogether to peculiar advantages in their surface for thereflection of light."

  "Dear boys, will you allow me to give my little guess on the subject?"asked Ardan.

  His companions were profuse in expressing their desire to hear it.

  "Well then," he resumed, "seeing that these bright streaks invariablystart from a certain point to radiate in all directions, why not supposethem to be streams of lava issuing from the crater and flowing down themountain side until they cooled?"

  "Such a supposition or something like it has been put forth byHerschel," replied Barbican; "but your own sense will convince you thatit is quite untenable when you consider that lava, however hot andliquid it may be at the commencement of its journey, cannot flow on forhundreds of miles, up hills, across ravines, and over plains, all thetime in streams of almost exactly equal width."

  "That theory of yours holds no more water than mine, Ardan," observedM'Nicholl.

  "Correct, Captain," replied the Frenchman; "Barbican has a trick ofknocking the bottom out of every weaker vessel. But let us hear what hehas to say on the subject himself. What is your theory. Barbican?"

  "My theory," said Barbican, "is pretty much the same as that latelypresented by an English astronomer, Nasmyth, who has devoted much studyand reflection to lunar matters. Of course, I only formulate my theory,I don't affirm it. These streaks are cracks, made in the Moon's surfaceby cooling or by shrinkage, through which volcanic matter has beenforced up by internal pressure. The sinking ice of a frozen lake, whenmeeting with some sharp pointed rock, cracks in a radiating manner:every one of its fissures then admits the water, which immediatelyspreads laterally over the ice pretty much as the lava spreads itselfover the lunar surface. This theory accounts for the radiating nature ofthe streaks, their great and nearly equal thickness, their immenselength, their inability to cast a shadow, and their invisibility at anytime except at or near the Full Moon. Still it is nothing but a theory,and I don't deny that serious objections may be brought against it."

  "Do you know, dear boys," cried Ardan, led off as usual by the slightestfancy, "do you know what I am thinking of when I look down on the greatrugged plains spread out beneath us?"

  "I can't say, I'm sure," replied Barbican, somewhat piqued at the littleattention he had secured for his theory.

  "Well, what are you thinking of?" asked M'Nicholl.

  "Spillikins!" answered Ardan triumphantly.

  "Spillikins?" cried his companions, somewhat surprised.

  "Yes, Spillikins! These rocks, these blocks, these peaks, these streaks,these cones, these cracks, these ramparts, these escarpments,--what arethey but a set of spillikins, though I acknowledge on a grand scale? Iwish I had a little hook to pull them one by one!"

  AN IMMENSE BATTLEFIELD.]

  "Oh, do be serious, Ardan!" cried Barbican, a little impatiently.

  "Certainly," replied Ardan. "Let us be serious, Captain, sinceseriousness best befits the subject in hand. What
do you think ofanother comparison? Does not this plain look like an immense battlefield piled with the bleaching bones of myriads who had slaughtered eachother to a man at the bidding of some mighty Caesar? What do you thinkof that lofty comparison, hey?"

  "It is quite on a par with the other," muttered Barbican.

  "He's hard to please, Captain," continued Ardan, "but let us try himagain! Does not this plain look like--?"

  "My worthy friend," interrupted Barbican, quietly, but in a tone todiscourage further discussion, "what you think the plain _looks like_ isof very slight import, as long as you know no more than a child what itreally _is_!"

  "Bravo, Barbican! well put!" cried the irrepressible Frenchman. "Shall Iever realize the absurdity of my entering into an argument with ascientist!"

  But this time the Projectile, though advancing northward with a prettyuniform velocity, had neither gained nor lost in its nearness to thelunar disc. Each moment altering the character of the fleeting landscapebeneath them, the travellers, as may well be imagined, never thought oftaking an instant's repose. At about half past one, looking to theirright on the west, they saw the summits of another mountain; Barbican,consulting his map, recognized _Eratosthenes_.

  This was a ring mountain, about 33 miles in diameter, having, like_Copernicus_, a crater of immense profundity containing central cones.Whilst they were directing their glasses towards its gloomy depths,Barbican mentioned to his friends Kepler's strange idea regarding theformation of these ring mountains. "They must have been constructed," hesaid, "by mortal hands."

  "With what object?" asked the Captain.

  "A very natural one," answered Barbican. "The Selenites must haveundertaken the immense labor of digging these enormous pits at places ofrefuge in which they could protect themselves against the fierce solarrays that beat against them for 15 days in succession!"

  "Not a bad idea, that of the Selenites!" exclaimed Ardan.

  "An absurd idea!" cried M'Nicholl. "But probably Kepler never knew thereal dimensions of these craters. Barbican knows the trouble and timerequired to dig a well in Stony Hill only nine hundred feet deep. To digout a single lunar crater would take hundreds and hundreds of years, andeven then they should be giants who would attempt it!"

  "Why so?" asked Ardan. "In the Moon, where gravity is six times lessthan on the Earth, the labor of the Selenites can't be compared withthat of men like us."

  "But suppose a Selenite to be six times smaller than a man like us!"urged M'Nicholl.

  "And suppose a Selenite never had an existence at all!" interposedBarbican with his usual success in putting an end to the argument. "Butnever mind the Selenites now. Observe _Eratosthenes_ as long as you havethe opportunity."

  "Which will not be very long," said M'Nicholl. "He is already sinkingout of view too far to the right to be carefully observed."

  "What are those peaks beyond him?" asked Ardan.

  "The _Apennines_," answered Barbican; "and those on the left are the_Carpathians_."

  "I have seen very few mountain chains or ranges in the Moon," remarkedArdan, after some minutes' observation.

  "Mountains chains are not numerous in the Moon," replied Barbican, "andin that respect her oreographic system presents a decided contrast withthat of the Earth. With us the ranges are many, the craters few; in theMoon the ranges are few and the craters innumerable."

  Barbican might have spoken of another curious feature regarding themountain ranges: namely, that they are chiefly confined to the northernhemisphere, where the craters are fewest and the "seas" the mostextensive.

  For the benefit of those interested, and to be done at once with thispart of the subject, we give in the following little table a list of thechief lunar mountain chains, with their latitude, and respectiveheights in English feet.

  _Name._ _Degrees of Latitude._ _Height._

  { _Altai Mountains_ 17 deg. to 28 13,000ft.Southern { _Cordilleras_ 10 to 20 12,000Hemisphere. { _Pyrenees_ 8 to 18 12,000 { _Riphean_ 5 to 10 2,600

  { _Haemus_ 10 to 20 6,300 { _Carpathian_ 15 to 19 6,000 { _Apennines_ 14 to 27 18,000Northern { _Taurus_ 25 to 34 8,500Hemisphere. { _Hercynian_ 17 to 29 3,400 { _Caucasus_ 33 to 40 17,000 { _Alps_ 42 to 30 10,000

  Of these different chains, the most important is that of the_Apennines_, about 450 miles long, a length, however, far inferior tothat of many of the great mountain ranges of our globe. They skirt thewestern shores of the _Mare Imbrium_, over which they rise in immensecliffs, 18 or 20 thousand feet in height, steep as a wall and castingover the plain intensely black shadows at least 90 miles long. Of Mt._Huyghens_, the highest in the group, the travellers were just barelyable to distinguish the sharp angular summit in the far west. To theeast, however, the _Carpathians_, extending from the 18th to 30thdegrees of east longitude, lay directly under their eyes and could beexamined in all the peculiarities of their distribution.

  Barbican proposed a hypothesis regarding the formation of thosemountains, which his companions thought at least as good as any other.Looking carefully over the _Carpathians_ and catching occasionalglimpses of semi-circular formations and half domes, he concluded thatthe chain must have formerly been a succession of vast craters. Then hadcome some mighty internal discharge, or rather the subsidence to which_Mare Imbrium_ is due, for it immediately broke off or swallowed up onehalf of those mountains, leaving the other half steep as a wall on oneside and sloping gently on the other to the level of the surroundingplains. The _Carpathians_ were therefore pretty nearly in the samecondition as the crater mountains _Ptolemy_, _Alpetragius_ and_Arzachel_ would find themselves in, if some terrible cataclysm, bytearing away their eastern ramparts, had turned them into a chain ofmountains whose towering cliffs would nod threateningly over the westernshores of _Mare Nubium_. The mean height of the _Carpathians_ is about6,000 feet, the altitude of certain points in the Pyrenees such as the_Port of Pineda_, or _Roland's Breach_, in the shadow of _Mont Perdu_.The northern slopes of the _Carpathians_ sink rapidly towards the shoresof the vast _Mare Imbrium_.

  Towards two o'clock in the morning, Barbican calculated the Projectileto be on the 20th northern parallel, and therefore almost immediatelyover the little ring mountain called _Pytheas_, about 4600 feet inheight. The distance of the travellers from the Moon at this pointcould not be more than about 750 miles, reduced to about 7 by means oftheir excellent telescopes.

  _Mare Imbrium_, the Sea of Rains here revealed itself in all itsvastness to the eyes of the travellers, though it must be acknowledgedthat the immense depression so called, did not afford them a very clearidea regarding its exact boundaries. Right ahead of them rose _Lambert_about a mile in height; and further on, more to the left, in thedirection of _Oceanus Procellarum_, _Euler_ revealed itself by itsglittering radiations. This mountain, of about the same height as_Lambert_, had been the object of very interesting calculations on thepart of Schroeter of Erfurt. This keen observer, desirous of inquiringinto the probable origin of the lunar mountains, had proposed to himselfthe following question: Does the volume of the crater appear to be equalto that of the surrounding ramparts? His calculations showing him thatthis was generally the case, he naturally concluded that these rampartsmust therefore have been the product of a single eruption, forsuccessive eruptions of volcanic matter would have disturbed thiscorrelation. _Euler_ alone, he found, to be an exception to this generallaw, as the volume of its crater appeared to be twice as great as thatof the mass surrounding it. It must therefore have been formed byseveral eruptions in succession, but in that case what had become of theejected matter?

  Theories of this nature and all manner of scientific questions were, ofcourse, perfectly permissible to terres
trial astronomers laboring underthe disadvantage of imperfect instruments. But Barbican could not thinkof wasting his time in any speculation of the kind, and now, seeing thathis Projectile perceptibly approached the lunar disc, though hedespaired of ever reaching it, he was more sanguine than ever of beingsoon able to discover positively and unquestionably some of the secretsof its formation.

  [Footnote C: We must again remind our readers that, in our map, thoughevery thing is set down as it appears to the eye not as it is reversedby the telescope, still, for the reason made so clear by Barbican, theright hand side must be the west and the left the east.]