All Around the Moon

Chapter 12

A BIRD'S EYE VIEW OF THE LUNAR MOUNTAINS.

I am rather inclined to believe myself that not one word of Ardan's

rhapsody had been ever heard by Barbican or M'Nicholl. Long before he

had spoken his last words, they had once more become mute as statues,

and now were both eagerly watching, pencil in hand, spyglass to eye, the

northern lunar hemisphere towards which they were rapidly but indirectly

approaching. They had fully made up their minds by this time that they

were leaving far behind them the central point which they would have

probably reached half an hour ago if they had not been shunted off their

course by that inopportune bolide.

About half past twelve o'clock, Barbican broke the dead silence by

saying that after a careful calculation they were now only about 875

miles from the Moon's surface, a distance two hundred miles less in

length than the lunar radius, and which was still to be diminished as

they advanced further north. They were at that moment ten degrees north

of the equator, almost directly over the ridge lying between the _Mare

Serenitatis_ and the _Mare Tranquillitatis_. From this latitude all the

way up to the north pole the travellers enjoyed a most satisfactory view

of the Moon in all directions and under the most favorable conditions.

By means of their spyglasses, magnifying a hundred times, they cut down

this distance of 875 miles to about 9. The great telescope of the Rocky

Mountains, 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; but

this advantage of nearness was considerably more than counterbalanced by

a want of clearness, resulting from the haziness and refractiveness of

the terrestrial atmosphere, not to mention those fatal defects in the

reflector that the art of man has not yet succeeded in remedying.

Accordingly, our travellers, armed with excellent telescopes--of just

power enough to be no injury to clearness,--and posted on unequalled

vantage ground, began already to distinguish certain details that had

probably never been noticed before by terrestrial observers. Even Ardan,

by this time quite recovered from his fit of sentiment and probably

infected a little by the scientific enthusiasm of his companions, began

to 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 lasted

perhaps ten minutes, "whither we are going I can't say; if we shall ever

revisit the Earth, I can't tell. Still, it is our duty so to act in all

respects as if these labors of ours were one day to be of service to our

fellow-creatures. Let us keep our souls free from every distraction. We

are now astronomers. We see now what no mortal eye has ever gazed on

before. This Projectile is simply a work room of the great Cambridge

Observatory lifted into space. Let us take observations!"

With these words, he set to work with a renewed ardor, in which his

companions fully participated. The consequence was that they soon had

several of the outline maps covered with the best sketches they could

make of the Moon's various aspects thus presented under such favorable

circumstances. They could now remark not only that they were passing the

tenth degree of north latitude, but that the Projectile followed almost

directly the twentieth degree of east longitude.

"One thing always puzzled me when examining maps of the Moon," observed

Ardan, "and I can't say that I see it yet as clearly as if I had thought

over the matter. It is this. I could understand, when looking through a

lens at an object, why we get only its reversed image--a simple law of

optics explains _that_. Therefore, in a map of the Moon, as the bottom

means the north and the top the south, why does not the right mean the

west and the left the east? I suppose I could have made this out by a

little thought, but thinking, that is reflection, not being my forte, it

is the last thing I ever care to do. Barbican, throw me a word or two on

the subject."

"I can see what troubles you," answered Barbican, "but I can also see

that 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, the

right hand must be the east, the left hand the west, and so on. That is

simply because we look _down_ from _above_. And such a map seen through

a 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 right

hand 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 not

they make you a professor of astronomy? Your hint will save me a world

of trouble."[C]

Aided by the _Mappa Selenographica_, the travellers could easily

recognize the different portions of the Moon over which they were now

moving. An occasional glance at our reduction of this map, given as a

frontispiece, will enable the gentle reader to follow the travellers on

the line in which they moved and to understand the remarks and

observations in which they occasionally indulged.

"Where are we now?" asked Ardan.

"Over the northern shores of the _Mare Nubium_," replied Barbican. "But

we 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? a

plain of solid sand, according to later authority? or an immense forest,

according to De la Rue of London, so far the Moon's most successful

photographer? This gentleman's authority, Ardan, would have given you

decided support in your famous dispute with the Captain at the meeting

near 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 for

ourselves; and in the meantime let us affirm nothing until we have good

grounds for positive assertion."

_Mare Nubium_, though not very clearly outlined on the maps, is easily

recognized by lying directly east of the regions about the centre. It

would appear as if this vast plain were sprinkled with immense lava

blocks shot forth from the great volcanoes on the right, _Ptolemaeus_,

_Alphonse_, _Alpetragius_ and _Arzachel_. But the Projectile advanced so

rapidly that these mountains soon disappeared, and the travellers were

not long before they could distinguish the great peaks that closed the

"Sea" on its northern boundary. Here a radiating mountain showed a

summit so dazzling with the reflection of the solar rays that Ardan

could not help crying out:

"It looks like one of the carbon points of an electric light projected

on 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 the

lunar wonders. It lifts its giant ramparts to upwards of 12,000 feet

above the level of the lunar surface. Being quite visible from the Earth

and well situated for observation, it is a favorite object for

astronomical study; this is particularly the case during the phase

existing between Last Quarter and the New Moon, when its vast shadows,

projected boldly from the east towards the west, allow its prodigious

dimensions to be measured.

After _Tycho_, which is situated in the southern hemisphere,

_Copernicus_ forms the most important radiating mountain in the lunar

disc. It looms up, single and isolated, like a gigantic light-house, on

the peninsula separating _Mare Nubium_ from _Oceanus Procellarum_ on one

side and from _Mare Imbrium_ on the other; thus illuminating with its

splendid radiation three "Seas" at a time. The wonderful complexity of

its bright streaks diverging on all sides from its centre presented a

scene alike splendid and unique. These streaks, the travellers thought,

could be traced further north than in any other direction: they fancied

they could detect them even in the _Mare Imbrium_, but this of course

might be owing to the point from which they made their observations. At

one o'clock in the morning, the Projectile, flying through space, was

exactly over this magnificent mountain.

In spite of the brilliant sunlight that was blazing around them, the

travellers 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 so

brightly through the ashy light of the Moon that it has been frequently

taken for a volcano in full activity. Whatever it may have been once,

however, it is certainly nothing more now than, like all the other

mountains on the visible side of the Moon, an extinct volcano, only with

a crater of such exceeding grandeur and sublimity as to throw utterly

into the shade everything like it on our Earth. The crater of Etna is at

most little more than a mile across. The crater of _Copernicus_ has a

diameter of at least 50 miles. Within it, the travellers could easily

discover by their glasses an immense number of terraced ridges, probably

landslips, alternating with stratifications resulting from successive

eruptions. Here and there, but particularly in the southern side, they

caught glimpses of shadows of such intense blackness, projected across

the plateau and lying there like pitch spots, that they could not tell

them from yawning chasms of incalculable depth. Outside the crater the

shadows were almost as deep, whilst on the plains all around,

particularly in the west, so many small craters could be detected that

the eye in vain attempted to count them.

"Many circular mountains of this kind," observed Barbican, "can be seen

on the lunar surface, but _Copernicus_, though not one of the greatest,

is one of the most remarkable on account of those diverging streaks of

bright light that you see radiating from its summit. By looking

steadily into its crater, you can see more cones than mortal eye ever

lit on before. They are so numerous as to render the interior plateau

quite rugged, and were formerly so many openings giving vent to fire and

volcanic matter. A curious and very common arrangement of this internal

plateau of lunar craters is its lying at a lower level than the external

plains, quite the contrary to a terrestrial crater, which generally has

its bottom much higher than the level of the surrounding country. It

follows therefore that the deep lying curve of the bottom of these ring

mountains would give a sphere with a diameter somewhat smaller than the

Moon's."

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

"I can't tell;" answered Barbican, "but, as a conjecture, I should say

that it is probably to the comparatively smaller area of the Moon and

the more violent character of her volcanic action that the extremely

rugged character of her surface is mainly due."

"Why, it's the _Campi Phlegraei_ or the Fire Fields of Naples over

again!" cried Ardan suddenly. "There's _Monte Barbaro_, there's the

_Solfatara_, there is the crater of _Astroni_, and there is the _Monte

Nuovo_, as plain as the hand on my body!"

"The great resemblance between the region you speak of and the general

surface of the Moon has been often remarked;" observed Barbican, "but

it is even still more striking in the neighborhood of _Theophilus_ on

the 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 a

better view of it?"

"Not the slightest," answered Barbican, "unless we go round the Moon and

return this way, like a satellite describing its orbit."

By this time they had arrived at a point vertical to the mountain

centre. _Copernicus's_ vast ramparts formed a perfect circle or rather a

pair of concentric circles. All around the mountain extended a dark

grayish plain of savage aspect, on which the peak shadows projected

themselves in sharp relief. In the gloomy bottom of the crater, whose

dimensions are vast enough to swallow Mont Blanc body and bones, could

be distinguished a magnificent group of cones, at least half a mile in

height and glittering like piles of crystal. Towards the north several

breaches could be seen in the ramparts, due probably to a caving in of

immense masses accumulated on the summit of the precipitous walls.

As already observed, the surrounding plains were dotted with numberless

craters mostly of small dimensions, except _Gay Lussac_ on the north,

whose crater was about 12 miles in diameter. Towards the southwest and

the 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 peninsula

jutted on _Oceanus Procellarum_, the plain looked like a sea of lava

wildly lashed for a while by a furious hurricane and then, when its

waves and breakers and driving ridges were at their wildest, suddenly

frozen into solidity. Over this rugged, rumpled, wrinkled surface and in

all directions, ran the wonderful streaks whose radiating point appeared

to be the summit of _Copernicus_. Many of them appeared to be ten miles

wide and hundreds of miles in length.

The travellers disputed for some time on the origin of these strange

radii, but could hardly be said to have arrived at any conclusion more

satisfactory than that already reached by some terrestrial observers.

To M'Nicholl's question:

"Why can't these streaks be simply prolonged mountain crests reflecting

the sun's rays more vividly by their superior altitude and comparative

smoothness?"

Barbican readily replied:

"These streaks _can't_ be mountain crests, because, if they were, under

certain conditions of solar illumination they should project

_shadows_--a thing which they have never been known to do under any

circumstances whatever. In fact, it is only during the period of the

full Moon that these streaks are seen at all; as soon as the sun's rays

become oblique, they disappear altogether--a proof that their appearance

is due altogether to peculiar advantages in their surface for the

reflection 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 invariably

start from a certain point to radiate in all directions, why not suppose

them to be streams of lava issuing from the crater and flowing down the

mountain side until they cooled?"

"Such a supposition or something like it has been put forth by

Herschel," replied Barbican; "but your own sense will convince you that

it is quite untenable when you consider that lava, however hot and

liquid it may be at the commencement of its journey, cannot flow on for

hundreds of miles, up hills, across ravines, and over plains, all the

time in streams of almost exactly equal width."

"That theory of yours holds no more water than mine, Ardan," observed

M'Nicholl.

"Correct, Captain," replied the Frenchman; "Barbican has a trick of

knocking the bottom out of every weaker vessel. But let us hear what he

has to say on the subject himself. What is your theory. Barbican?"

"My theory," said Barbican, "is pretty much the same as that lately

presented by an English astronomer, Nasmyth, who has devoted much study

and 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 surface

by cooling or by shrinkage, through which volcanic matter has been

forced up by internal pressure. The sinking ice of a frozen lake, when

meeting with some sharp pointed rock, cracks in a radiating manner:

every one of its fissures then admits the water, which immediately

spreads laterally over the ice pretty much as the lava spreads itself

over the lunar surface. This theory accounts for the radiating nature of

the streaks, their great and nearly equal thickness, their immense

length, their inability to cast a shadow, and their invisibility at any

time 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 slightest

fancy, "do you know what I am thinking of when I look down on the great

rugged plains spread out beneath us?"

"I can't say, I'm sure," replied Barbican, somewhat piqued at the little

attention 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 are

they but a set of spillikins, though I acknowledge on a grand scale? I

wish I had a little hook to pull them one by one!"

[Illustration: AN IMMENSE BATTLEFIELD.]

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

"Certainly," replied Ardan. "Let us be serious, Captain, since

seriousness best befits the subject in hand. What do you think of

another comparison? Does not this plain look like an immense battle

field piled with the bleaching bones of myriads who had slaughtered each

other to a man at the bidding of some mighty Caesar? What do you think

of 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 him

again! Does not this plain look like--?"

"My worthy friend," interrupted Barbican, quietly, but in a tone to

discourage further discussion, "what you think the plain _looks like_ is

of very slight import, as long as you know no more than a child what it

really _is_!"

"Bravo, Barbican! well put!" cried the irrepressible Frenchman. "Shall I

ever realize the absurdity of my entering into an argument with a

scientist!"

But this time the Projectile, though advancing northward with a pretty

uniform velocity, had neither gained nor lost in its nearness to the

lunar disc. Each moment altering the character of the fleeting landscape

beneath them, the travellers, as may well be imagined, never thought of

taking an instant's repose. At about half past one, looking to their

right 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 the

formation of these ring mountains. "They must have been constructed," he

said, "by mortal hands."

"With what object?" asked the Captain.

"A very natural one," answered Barbican. "The Selenites must have

undertaken the immense labor of digging these enormous pits at places of

refuge in which they could protect themselves against the fierce solar

rays 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 the

real dimensions of these craters. Barbican knows the trouble and time

required to dig a well in Stony Hill only nine hundred feet deep. To dig

out a single lunar crater would take hundreds and hundreds of years, and

even then they should be giants who would attempt it!"

"Why so?" asked Ardan. "In the Moon, where gravity is six times less

than on the Earth, the labor of the Selenites can't be compared with

that 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!" interposed

Barbican with his usual success in putting an end to the argument. "But

never mind the Selenites now. Observe _Eratosthenes_ as long as you have

the opportunity."

"Which will not be very long," said M'Nicholl. "He is already sinking

out 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," remarked

Ardan, after some minutes' observation.

"Mountains chains are not numerous in the Moon," replied Barbican, "and

in that respect her oreographic system presents a decided contrast with

that of the Earth. With us the ranges are many, the craters few; in the

Moon the ranges are few and the craters innumerable."

Barbican might have spoken of another curious feature regarding the

mountain ranges: namely, that they are chiefly confined to the northern

hemisphere, where the craters are fewest and the "seas" the most

extensive.

For the benefit of those interested, and to be done at once with this

part of the subject, we give in the following little table a list of the

chief lunar mountain chains, with their latitude, and respective

heights in English feet.

Barbican proposed a hypothesis regarding the formation of those

mountains, which his companions thought at least as good as any other.

Looking carefully over the _Carpathians_ and catching occasional

glimpses of semi-circular formations and half domes, he concluded that

the chain must have formerly been a succession of vast craters. Then had

come some mighty internal discharge, or rather the subsidence to which

_Mare Imbrium_ is due, for it immediately broke off or swallowed up one

half of those mountains, leaving the other half steep as a wall on one

side and sloping gently on the other to the level of the surrounding

plains. The _Carpathians_ were therefore pretty nearly in the same

condition as the crater mountains _Ptolemy_, _Alpetragius_ and

_Arzachel_ would find themselves in, if some terrible cataclysm, by

tearing away their eastern ramparts, had turned them into a chain of

mountains whose towering cliffs would nod threateningly over the western

shores of _Mare Nubium_. The mean height of the _Carpathians_ is about

6,000 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 shores

of the vast _Mare Imbrium_.

Towards two o'clock in the morning, Barbican calculated the Projectile

to be on the 20th northern parallel, and therefore almost immediately

over the little ring mountain called _Pytheas_, about 4600 feet in

height. The distance of the travellers from the Moon at this point

could not be more than about 750 miles, reduced to about 7 by means of

their excellent telescopes.

_Mare Imbrium_, the Sea of Rains here revealed itself in all its

vastness to the eyes of the travellers, though it must be acknowledged

that the immense depression so called, did not afford them a very clear

idea regarding its exact boundaries. Right ahead of them rose _Lambert_

about a mile in height; and further on, more to the left, in the

direction of _Oceanus Procellarum_, _Euler_ revealed itself by its

glittering radiations. This mountain, of about the same height as

_Lambert_, had been the object of very interesting calculations on the

part of Schroeter of Erfurt. This keen observer, desirous of inquiring

into the probable origin of the lunar mountains, had proposed to himself

the following question: Does the volume of the crater appear to be equal

to that of the surrounding ramparts? His calculations showing him that

this was generally the case, he naturally concluded that these ramparts

must therefore have been the product of a single eruption, for

successive eruptions of volcanic matter would have disturbed this

correlation. _Euler_ alone, he found, to be an exception to this general

law, as the volume of its crater appeared to be twice as great as that

of the mass surrounding it. It must therefore have been formed by

several eruptions in succession, but in that case what had become of the

ejected matter?

Theories of this nature and all manner of scientific questions were, of

course, perfectly permissible to terrestrial astronomers laboring under

the disadvantage of imperfect instruments. But Barbican could not think

of wasting his time in any speculation of the kind, and now, seeing that

his Projectile perceptibly approached the lunar disc, though he

despaired of ever reaching it, he was more sanguine than ever of being

soon able to discover positively and unquestionably some of the secrets

of its formation.

[Footnote C: We must again remind our readers that, in our map, though

every thing is set down as it appears to the eye not as it is reversed

by the telescope, still, for the reason made so clear by Barbican, the

right hand side must be the west and the left the east.]