The Observers Of The Moon

: All Around The Moon

Barbican's happy conjecture had probably hit the nail on the head. The

divergency even of a second may amount to millions of miles if you only

have your lines long enough. The Projectile had certainly gone off its

direct course; whatever the cause, the fact was undoubted. It was a

great pity. The daring attempt must end in a failure due altogether to a

fortuitous accident, against which no human foresight could have

po sibly taken precaution. Unless in case of the occurrence of some

other most improbable accident, reaching the Moon was evidently now

impossible. To failure, therefore, our travellers had to make up their

minds.



But was nothing to be gained by the trip? Though missing actual contact

with the Moon, might they not pass near enough to solve several problems

in physics and geology over which scientists had been for a long time

puzzling their brains in vain? Even this would be some compensation for

all their trouble, courage, and intelligence. As to what was to be their

own fate, to what doom were themselves to be reserved--they never

appeared to think of such a thing. They knew very well that in the midst

of those infinite solitudes they should soon find themselves without

air. The slight supply that kept them from smothering could not

possibly last more than five or six days longer. Five or six days! What

of that? Quand meme! as Ardan often exclaimed. Five or six days were

centuries to our bold adventurers! At present every second was a year in

events, and infinitely too precious to be squandered away in mere

preparations for possible contingencies. The Moon could never be

reached, but was it not possible that her surface could be carefully

observed? This they set themselves at once to find out.



The distance now separating them from our Satellite they estimated at

about 400 miles. Therefore relatively to their power of discovering the

details of her disc, they were still farther off from the Moon than some

of our modern astronomers are to-day, when provided with their powerful

telescopes.



We know, for example, that Lord Rosse's great telescope at Parsonstown,

possessing a power of magnifying 6000 times, brings the Moon to within

40 miles of us; not to speak of Barbican's great telescope on the summit

of Long's Peak, by which the Moon, magnified 48,000 times, was brought

within 5 miles of the Earth, where it therefore could reveal with

sufficient distinctness every object above 40 feet in diameter.



Therefore our adventurers, though at such a comparatively small

distance, could not make out the topographical details of the Moon with

any satisfaction by their unaided vision. The eye indeed could easily

enough catch the rugged outline of these vast depressions improperly

called "Seas," but it could do very little more. Its powers of

adjustability seemed to fail before the strange and bewildering scene.

The prominence of the mountains vanished, not only through the

foreshortening, but also in the dazzling radiation produced by the

direct reflection of the solar rays. After a short time therefore,

completely foiled by the blinding glare, the eye turned itself

unwillingly away, as if from a furnace of molten silver.



The spherical surface, however, had long since begun to reveal its

convexity. The Moon was gradually assuming the appearance of a gigantic

egg with the smaller end turned towards the Earth. In the earlier days

of her formation, while still in a state of mobility, she had been

probably a perfect sphere in shape, but, under the influence of

terrestrial gravity operating for uncounted ages, she was drawn at last

so much towards the centre of attraction as to resemble somewhat a

prolate spheriod. By becoming a satellite, she had lost the native

perfect regularity of her outline; her centre of gravity had shifted

from her real centre; and as a result of this arrangement, some

scientists have drawn the conclusion that the Moon's air and water have

been attracted to that portion of her surface which is always invisible

to the inhabitants of the Earth.



The convexity of her outline, this bulging prominence of her surface,

however, did not last long. The travellers were getting too near to

notice it. They were beginning to survey the Moon as balloonists survey

the Earth. The Projectile was now moving with great rapidity--with

nothing like its initial velocity, but still eight or nine times faster

than an express train. Its line of movement, however, being oblique

instead of direct, was so deceptive as to induce Ardan to flatter

himself that they might still reach the lunar surface. He could never

persuade himself to believe that they should get so near their aim and

still miss it. No; nothing might, could, would or should induce him to

believe it, he repeated again and again. But Barbican's pitiless logic

left him no reply.



"No, dear friend, no. We can reach the Moon only by a fall, and we don't

fall. Centripetal force keeps us at least for a while under the lunar

influence, but centrifugal force drives us away irresistibly."



These words were uttered in a tone that killed Ardan's last and fondest

hope.



* * * * *



The portion of the Moon they were now approaching was her northern

hemisphere, found usually in the lower part of lunar maps. The lens of a

telescope, as is well known, gives only the inverted image of the

object; therefore, when an upright image is required, an additional

glass must be used. But as every additional glass is an additional

obstruction to the light, the object glass of a Lunar telescope is

employed without a corrector; light is thereby saved, and in viewing the

Moon, as in viewing a map, it evidently makes very little difference

whether we see her inverted or not. Maps of the Moon therefore, being

drawn from the image formed by the telescope, show the north in the

lower part, and vice versa. Of this kind was the Mappa

Selenographica, by Beer and Maedler, so often previously alluded to and

now carefully consulted by Barbican. The northern hemisphere, towards

which they were now rapidly approaching, presented a strong contrast

with the southern, by its vast plains and great depressions, checkered

here and there by very remarkable isolated mountains.[A]



At midnight the Moon was full. This was the precise moment at which the

travellers would have landed had not that unlucky bolide drawn them off

the track. The Moon was therefore strictly up to time, arriving at the

instant rigidly determined by the Cambridge Observatory. She occupied

the exact point, to a mathematical nicety, where our 28th parallel

crossed the perigee. An observer posted in the bottom of the Columbiad

at Stony Hill, would have found himself at this moment precisely under

the Moon. The axis of the enormous gun, continued upwards vertically,

would have struck the orb of night exactly in her centre.



It is hardly necessary to tell our readers that, during this memorable

night of the 5th and 6th of December, the travellers had no desire to

close their eyes. Could they do so, even if they had desired? No! All

their faculties, thoughts, and desires, were concentrated in one single

word: "Look!" Representatives of the Earth, and of all humanity past and

present, they felt that it was with their eyes that the race of man

contemplated the lunar regions and penetrated the secrets of our

satellite! A certain indescribable emotion therefore, combined with an

undefined sense of responsibility, held possession of their hearts, as

they moved silently from window to window.



Their observations, recorded by Barbican, were vigorously remade,

revised, and re-determined, by the others. To make them, they had

telescopes which they now began to employ with great advantage. To

regulate and investigate them, they had the best maps of the day.



Whilst occupied in this silent work, they could not help throwing a

short retrospective glance on the former Observers of the Moon.



The first of these was Galileo. His slight telescope magnified only

thirty times, still, in the spots flecking the lunar surface, like the

eyes checkering a peacock's tail, he was the first to discover mountains

and even to measure their heights. These, considering the difficulties

under which he labored, were wonderfully accurate, but unfortunately he

made no map embodying his observations.



A few years afterwards, Hevel of Dantzic, (1611-1688) a Polish

astronomer--more generally known as Hevelius, his works being all

written in Latin--undertook to correct Galileo's measurements. But as

his method could be strictly accurate only twice a month--the periods of

the first and second quadratures--his rectifications could be hardly

called successful.



Still it is to the labors of this eminent astronomer, carried on

uninterruptedly for fifty years in his own observatory, that we owe the

first map of the Moon. It was published in 1647 under the name of

Selenographia. He represented the circular mountains by open spots

somewhat round in shape, and by shaded figures he indicated the vast

plains, or, as he called them, the seas, that occupied so much of her

surface. These he designated by names taken from our Earth. His map

shows you a Mount Sinai the midst of an Arabia, an AEtna in the

centre of a Sicily, Alps, Apennines, Carpathians, a

Mediterranean, a Palus Maeolis, a Pontus Euxinus, and a Caspian

Sea. But these names seem to have been given capriciously and at

random, for they never recall any resemblance existing between

themselves and their namesakes on our globe. In the wide open spot, for

instance, connected on the south with vast continents and terminating in

a point, it would be no easy matter to recognize the reversed image of

the Indian Peninsula, the Bay of Bengal, and Cochin China.

Naturally, therefore, these names were nearly all soon dropped; but

another system of nomenclature, proposed by an astronomer better

acquainted with the human heart, met with a success that has lasted to

the present day.



This was Father Riccioli, a Jesuit, and (1598-1671) a contemporary of

Hevelius. In his Astronomia Reformata, (1665), he published a rough

and incorrect map of the Moon, compiled from observations made by

Grimaldi of Ferrara; but in designating the mountains, he named them

after eminent astronomers, and this idea of his has been carefully

carried out by map makers of later times.



A third map of the Moon was published at Rome in 1666 by Dominico

Cassini of Nice (1625-1712), the famous discoverer of Saturn's

satellites. Though somewhat incorrect regarding measurements, it was

superior to Riccioli's in execution, and for a long time it was

considered a standard work. Copies of this map are still to be found,

but Cassini's original copper-plate, preserved for a long time at the

Imprimerie Royale in Paris, was at last sold to a brazier, by no less

a personage than the Director of the establishment himself, who,

according to Arago, wanted to get rid of what he considered useless

lumber!



La Hire (1640-1718), professor of astronomy in the College de France,

and an accomplished draughtsman, drew a map of the Moon which was

thirteen feet in diameter. This map could be seen long afterwards in the

library of St. Genevieve, Paris, but it was never engraved.



About 1760, Mayer, a famous German astronomer and the director of the

observatory of Goettingen, began the publication of a magnificent map of

the Moon, drawn after lunar measurements all rigorously verified by

himself. Unfortunately his death in 1762 interrupted a work which would

have surpassed in accuracy every previous effort of the kind.



Next appears Schroeter of Erfurt (1745-1816), a fine observer (he first

discovered the Lunar Rills), but a poor draughtsman: his maps are

therefore of little value. Lohrman of Dresden published in 1838 an

excellent map of the Moon, 15 inches in diameter, accompanied by

descriptive text and several charts of particular portions on a larger

scale.



But this and all other maps were thrown completely into the shade by

Beer and Maedler's famous Mappa Selenographica, so often alluded to in

the course of this work. This map, projected orthographically--that is,

one in which all the rays proceeding from the surface to the eye are

supposed to be parallel to each other--gives a reproduction of the lunar

disc exactly as it appears. The representation of the mountains and

plains is therefore correct only in the central portion; elsewhere,

north, south, east, or west, the features, being foreshortened, are

crowded together, and cannot be compared in measurement with those in

the centre. It is more than three feet square; for convenient reference

it is divided into four parts, each having a very full index; in short,

this map is in all respects a master piece of lunar cartography.[B]



After Beer and Maedler, we should allude to Julius Schmitt's (of Athens)

excellent selenographic reliefs: to Doctor Draper's, and to Father

Secchi's successful application of photography to lunar representation;

to De La Rue's (of London) magnificent stereographs of the Moon, to be

had at every optician's; to the clear and correct map prepared by

Lecouturier and Chapuis in 1860; to the many beautiful pictures of the

Moon in various phases of illumination obtained by the Messrs. Bond of

Harvard University; to Rutherford's (of New York) unparalleled lunar

photographs; and finally to Nasmyth and Carpenter's wonderful work on

the Moon, illustrated by photographs of her surface in detail, prepared

from models at which they had been laboring for more than a quarter of

the century.



Of all these maps, pictures, and projections, Barbican had provided

himself with only two--Beer and Maedler's in German, and Lecouturier and

Chapuis' in French. These he considered quite sufficient for all

purposes, and certainly they considerably simplified his labors as an

observer.



His best optical instruments were several excellent marine telescopes,

manufactured especially under his direction. Magnifying the object a

hundred times, on the surface of the Earth they would have brought the

Moon to within a distance of somewhat less than 2400 miles. But at the

point to which our travellers had arrived towards three o'clock in the

morning, and which could hardly be more than 12 or 1300 miles from the

Moon, these telescopes, ranging through a medium disturbed by no

atmosphere, easily brought the lunar surface to within less than 13

miles' distance from the eyes of our adventurers.



Therefore they should now see objects in the Moon as clearly as people

can see the opposite bank of a river that is about 12 miles wide.



[Footnote A: In our Map of the Moon, prepared expressly for this work,

we have so far improved on Beer and Maedler as to give her surface as it

appears to the naked eye: that is, the north is in the north; only we

must always remember that the west is and must be on the right hand.]



[Footnote B: In our Map the Mappa Selenographica is copied as closely

and as fully as is necessary for understanding the details of the story.

For further information the reader is referred to Nasmyth's late

magnificent work: the MOON.]