Popular Science Monthly/Volume 19/August 1881/Lunar Lore and Portraiture
FROM the remotest periods of which we have quoted or written records, the moon has been an object of adoring and speculative contemplation. As the babe in the cradle, crowing and smiling, stretches out its tiny hands to grasp the shining flame of the distant candle, so the infant races of the world gazed at the radiant orb above them, seeking to grasp and penetrate its mystic beauties.
Nor is it to be marveled at, when we consider that this planet was the most brilliant and changeable, as well as the nearest and apparently largest celestial body that presented itself to their nightly view, and that in the clear, exquisite ether of Arabian skies, and the calm nights of India and Egypt, it shone among the heavenly host with a luster unknown to dwellers in the crowded cities of a northern clime.
But the children of these tropic lands did something more than gaze, speculate, and admire: with supreme patience they reared lofty towers and grand pyramids, and invented instruments which have led up step by step to the transit instrument, the micrometer, and the telescope of to-day. A college of astronomy was founded by the priesthood of Egypt, the worship of the moon growing out of their frequent use of her pictured or carved image in making their meteorological announcements to the people; as, for instance, when the Nile was about to overflow, warning heralds were sent through the streets bearing aloft the familiar symbols of the river goddess, and a gilded figure of the moon in the phase it would present at the date of the expected rising.
In the course of time, the signification was forgotten, the symbol was worshiped, and finally what it represented deified. The moon no longer appeared to the unlettered populace as merely a brilliant lamp suspended from a revolving dome, and shining until extinguished by the waters of the ocean, but now was looked upon with awe as a region of sublime mysteries.
This veneration of the moon gradually spread with population to all parts of the world. We have records of ancient Chinese ceremonials; relics found among Druidical remains in Western Europe; accounts of astronomical picture-writings of a religious character, and lunar calendars of gold, silver, and stone, discovered in ancient temple-ruins in Mexico, Central and South America.
Among the buildings devoted to lunar worship may be mentioned the wonderful Temple of Diana at Ephesus, built at the combined expense of the nations of Asia, and the magnificent mansion of the moon adjoining the Temple of the Sun in ancient Cuzco; this building was in form a pyramidal pavilion with doors and inclosures completely incrusted with glittering silver. Within, on the southern wall, was a painting in white, presenting the moon as a beautiful woman; on either side along the eastern and western walls, on massive thrones of silver, were seated the dead queens of Peru, embalmed and arrayed in regal splendor.
In an elegant pavilion, covered with plates of the precious metal, adjoining the mansion, were apartments for the accommodation of her waiting-maids, the stars.
There was also an elaborate circular Temple of the Moon on a lofty hill near Quito, so arranged that the moonlight, falling through certain openings, shone directly on a silver image suspended from a blue roof emblazoned with stars.
Priesthoods and orders of priestesses existed in ancient Greece, Italy, India, Egypt, Britain, and America, fearful penalties attaching to broken vows or neglect of offices.
Many astronomers, whose quoted works are lost, flourished before Christ; their curious theories have been preserved in ancient writings of a later period. It is exceedingly interesting to trace, step by step, the changes of opinion wrought by gradual discovery in regard to the physical condition of the moon. This—orb variously supposed to be a brilliant disk-shaped body formed from mist congealed by fire; a mass of fiery and opaque elements; a circle of porous substance like pumice-stone, receiving light from a luminous ether; and a sphere, one half of which was burning—was finally pronounced by Anaxagoras, the Greek philosopher, in the year 500 b. c, to be an earth with mountains and valleys like our own.
For this opinion, and his belief that the moon was as large as the Peloponnesus, Anaxagoras was ridiculed by the learned men of his time. Six hundred years later, Plutarch supported the views of his ancient predecessor; but it was not until the application of the first telescope that any certain knowledge of the planet was gained. This instrument caused a complete revolution of ideas in astronomy. Galileo's plains, mountains, and valleys, were facts, whereas those of Anaxagoras had been matters of conjecture. Imagination soon peopled the moon with a peculiar race of beings, covered it with grand forests and cities, and all that pertains to a habitable world. Fortifications were discovered; consequently, the Lunarians were a warlike people. Certain bright points on the dark portion of the moon's disk were proclaimed to be conflagrations, or volcanic eruptions, or perhaps fireworks in honor of some lunar event.
A German astronomer proposed the building of an immense triangle on the plains of Siberia as a means of mathematical correspondence with the moon's inhabitants, believing they would build one in reply. A brother scientist, commenting on this novel signal-service, naively declared that "many more foolish projects had been carried out successfully."
Improved instruments have demonstrated that life, as we understand it, is impossible on the lunar body, revealing to us that it is composed of rocks and matter of a highly reflective character; its surface being broken up by ranges of lofty, perpendicular mountains, craters of elevation, precipitous caves and hollows; that the dark plains are the beds of oceans long ago evaporated or withdrawn into the interior of the planet; that it is subject to enormous degrees of heat and cold, has no water or apparent atmosphere, and, if so, neither wind, wave, nor sound.
Nothing varies the monotony of the long days and nights composing the lunar year, save the changing positions of the intensely black shadows falling from hills and mountains that cut off or fling back into space the white light of the sun; or the swift, silent fall of the crumbling walls of some hollow crater.
On looking at the moon through the telescope for the first time, one is struck by the melancholy character of its broken yet shining surface. Desolate plains are seen stretching away from the central view to the dazzling sunlit edge where, under the immedate solar glare, they seem sheeted with everlasting snow. To the right, as they gradually approach the region of darkness, the white softens into the greenish gray of a sandy desert.
But, ho! what tracks are these like the footprints of huge camels? Has some celestial caravan passed this way and disappeared from sight in the far south? Shall we see another wending its slow way after?
And yonder—another marvel—a fountain of silver sending from its argent depths rivers of precious metal to wander over sandy plains! Will the wonders never cease? Beyond, on the brilliant terminator, are promontories of pearly luster jutting out into seas of darkness, and, remoter still, pendent stars shining over ebon gulfs!
Gentle astronomer, increase your magnifying, for we long to investigate, space by space, this moon whose beauties we have never known before!
Ah, the footprints are footprints no longer—they are cup-shaped hollows innumerable! These drifts, as of snow, are ranges of mountains, and the promontories and pendent stars are crags and mountaintops just catching the rays of dawn. Down their steep sides lie the shadows of night; the topmost peaks alone have caught the glory! And beyond is the night-side of the moon, illumined by dim earthlight.
The power is increased again, and now we are looking down into a crater, and behold! one, two, three mountains rising from its central depths; their peaks hardly reach the level of its ring-shaped summit!
Here is another crater, with a solitary peak rising from its bottom. See, down below, piles of rocks are lying around its base. Three miles deep, by measurement, what awful gulfs of darkness these at the new moon, when no light falls within their silent hollows! What reservoirs of fiercest heat when, like a giant eye, the sun glares down and floods their unsheltered spaces!
Let us turn once more to those bright fountains and rivers of silver, astronomically called "rilles." Here they are, brilliant as ever; but we can learn nothing of their nature by gazing at them. The astronomer will tell you the latest theory—namely, that when the moon's crust was cooling, ages ago, it contracted, causing immense corrugations, wrinkles, and nodules, and in many places deep rents, admitting water to the heated nucleus, producing volcanic action; in many of these fissures rose up molten matter, filling the central openings to the brim, and extending all the length of the cracks.
You have already noticed that besides the craters there are innumerable craterlets. Your guide will explain again—referring to some great authority—the fanciful and plausible theory that these were the result of downfalls of meteoric rain when the lunar crust was still in the plastic state.
Let us observe the plains again: near the left border, under the sun-glare, they are too brilliant for definition of detail; near the central view their greenish-gray surfaces may be examined in the apparent twilight of the moon. Their seemingly smooth character and color prove them to be beds of oceans of the past lunar ages. These marine bottoms are not smooth in reality, but are seamed and traversed by ranges of hills and mountains, and craters thousands of feet deep! Did these, like monster mouths, swallow the remnants of the evaporating oceans?
The longer one studies this lonely globe, so beautiful in its desolation, the more real does it become to the eye. Here rise veritable mountains casting their black shadows on the plains. There stretch deserts thousands of miles in length, visible throughout all their breadth, for there is little if any perspective on the moon.
To the east is reigning the brilliant lunar day, so long, so fierce, so hot; beyond it is evening, with sunset touching the mountain-peaks on the terminator; in the remotest west, midnight!
This is more than one can see on one's own terrestrial ball, where the vision is bounded by atmosphere, and objects "by degrees grow beautifully less."
One must not look at the full moon to view all these wonders, for seen through the telescope it is merely a brilliant, dazzling sphere; mountains, valleys, and plains are flooded with intensest light; no shadows fall; the white glitter is intolerable!
It must be viewed in six phases: the three-days-old crescent, five days' old, seven days' old or first quarter, the last quarter, and the last three days of the old moon; thus may be seen the four visible sevenths of the lunar globe, all that is ever seen by mortal eye.
From time immemorial the graphic art has been employed in representing the moon according to the prevailing theory of the time, as seen by the naked eye or through the telescope. In the picture-writings of both continents, in their carvings and metal castings, were seen the first rude presentations of the planet in her various phases.
The first astronomical moon-drawing is attributed to Anaxagoras; it was probably executed more than twenty-three centuries ago. Since his time numberless drawings have been made, all more or less imperfect. In 1609, Galileo, from observations made with a telescope of his own invention, constructed the first lunar map, which is valuable only as marking the first great advance toward precise knowledge of the moon's surface.
Scheiner, a German professor, and Schirlaus, made numerous sketches of a like character; during the same century Langrenus executed special drawings of different points on the moon, naming them after celebrated personages.
About the year 1647 appeared the "Selenographia," a work by Hevelius, of Dantzic, wherein was the first lunar map at all approaching correctness. Although Father Riccioli, of Bologna, published a chart in 1651, and Dominic Cassini another in 1680, fuller as to detail, Hevelius's chart was considered the best authority for one hundred years after its issue, his knowledge of drawing contributing greatly to its success.
In 1775 appeared Tobias Mayer's small lunar chart, the most accurate yet published, and consulted as such until 1824. The first scientific attempt to delineate the characteristic features of the moon in detail was made by Lohrmann, a land-surveyor in Dresden: he intended to publish a chart on a large scale in twenty-five sections, but failing eyesight compelled him to forego his ambitious project; he, however, executed a fine lunar map, fifteen and a quarter inches in diameter, in 1838.
Schroeter, of Lilienthal, labored with the greatest patience, making a long series of observations, but, owing to a lack of graphic skill, his "Selenographische Fragmente" was not a true exponent of his ideas.
In 1837 appeared Beer and Mädler's "Der Monde," one of the most valuable contributions to astronomical literature; the chart accompanying it shows an immense amount of detail, all the principal objects seen through the telescope being given in outline. Webb's "Map of the Moon," reduced from this chart, is of great value to the student, retaining as it does all the most important features and omitting confusing detail.
The most interesting and wonderful chart yet published is that recently completed by Schmidt, of Athens, the result of more than a quarter of a century's observations of the moon, and for which the author made more than a thousand drawings.
The most diffuse and clearly illustrated work published within the last decade is Neison's "Moon," the accompanying chart in sections giving the principal features of the planet's surface. Nasmyth and Carpenter's "Moon," illustrated by fine photographs of prominent insulated peaks, mountain-ranges, and crateriform mountains, and Proctor's "Motions, Aspect, Scenery, and Physical Condition of the Moon," furnish delightful and instructive text to the general reader.
Very beautiful drawings of single craters, viewed under high power, have been made by Secchi, Nasmyth, and Carpenter. Bertch, Arnauld, Temple, and Harriot, a young English astronomer, have given us topographical lunar drawings of considerable merit.
The greatest change in lunar illustration occurred in the application of the telescope to photography. The moon, sighted by a telescope provided with a meniscus lens for the collection of the actinic rays, and kept in the field by the driving-clock, casts her image on a sensitive plate, which, being developed, gives all the numerous details of the lunar surface dimly and minutely, to be sure, but capable of enlargement and printing to apparent life-size.
Draper photographed the moon in 1840; Bond, in 1850; De La Rue and Rutherfurd, in 1857, the former discovering that the pictures could be combined in the stereoscope so as to appear globular. Photographic representations of the moon, in her various phases, are eminently picturesque, though lacking distinct detail; they are, however, correct, for, granted that the apparatus is properly adjusted, the sun paints with perfect truth.
Nelson's maps of the moon were first done in water-color. Some have also been done in this vehicle by the "Moon Committee" of the Royal Astronomical Society of London." It has been reserved for Henry Harrison, a young American astronomer and artist, to paint the first and only true telescopic portrait of the moon in oil-colors.
"Not difiicult to do!" exclaims the uninitiated observer.
"Impossible!" returns the scientist. "No one can paint the moon in detail."
Nevertheless, our aesthetic astronomer set to work to paint the six phases, which would give a portrait not only picturesque, but so true to details and coloring that it could be offered to the scrutiny of eyes long practiced in the nightly study of the orb itself eyes that would be quick to detect the absence of the smallest crater, the presence of a superfluous peak.
After the professional duties of the day, Mr. Harrison, when the weather was propitious, passed his time in making observations of the heavens. Seated at the telescope, he would pass hour after hour, studying the surface of the lunar orb.
On one of these occasions, a summer evening, singularly calm and clear, his wife joined him. Sitting for some time completely absorbed in the brilliant spectacle, she at last exclaimed: "Henry, paint that, if you can; it is beautiful beyond description!"
The thought had not then occurred to him. Now his wife's fanciful challenge awakened a desire to paint the moon in colors; for, as the most exquisite portrait in black and white can not express the bloom of lip and cheek, or the burnished gold of sunny tresses, neither could the various astronomical drawings now in existence express the beautiful gradations of light, the delicate tinting of the gray-green plains, the brilliant peaks and sunlit edge that make the telescopic moon the most interesting of celestial bodies.
Hitherto the human face and form had engaged his pencil: he could command sittings of his subject where and when he chose; direct the light and shade; arrange the drapery, select the pose: but here was to be another order of affairs; a willful, fitful queen, subject to no human wishes, obedient to no mortal command. There were only two evenings in the month in which to study the chosen phase on one of them or both her Majesty might command the vapors of the air and veil herself in impenetrable cloud. Another month she might summon the forces of the winds, and dance with them a demon's dance upon the telescopic mirror; and, on the next night, when the chosen phase was past, appear serenely beautiful upon a field of stainless blue.
It may be fairly asked how the artist, contending with so many difficulties, could paint a faithful portrait at all. As it would be impossible in the moon's short sittings, if one may use the term, to catch and fix accurately the varied details that crowd its surface with the pencil alone, Mr. Harrison resorted, as a first step, to photographic aid. Taking Rutherfurd's negative of the three-days-old crescent, he enlarged it to the desired size by means of an oxyhydrogen light, throwing the image from the glass to his canvas. Thereon he sketched the outlines of the craters, plains, and mountain-ranges, as the enlarged negative indistinctly presented them. Then, by the light of a lantern suspended from the observatory roof, from time to time consulting the image of the moon mirrored in the telescope, he sharpened every detail, marking out the intensely black shadows and the equally intense high lights on the topmost peaks of the terminator, the dazzling edge, and the gradations of tint on the far-stretching plains.
Slowly—for eighteen months rolled by before the first phase was finished—pencil and pigment, guided by artist eye and hand, did their work, and there stood a faithful portrait of the three-days-old crescent, twenty-one inches in diameter, showing the terminator at Messier.
The edge toward the left is brilliantly illuminated by the sun, whose proximity casts a yellowish tint over the plains, that gradually fades into grayish-green in the shadows of night on the right edge or terminator. On the remainder of the disk, faintly illumined by earthlight, may be dimly seen outlines of the Apennine ranges, and the craters of Copernicus and Tycho.
The brilliant convexity of the moon is well thrown out by the clear dark-blue of the sky in which it floats, the painted revelation of the wonders of a sister world. Plainer than words, this colored image tells the story of an activity of tempests, and bubbling caldrons of fire long since burned out; of oceans evaporated and drawn into the deepest depths of a dying world—of present silence and empty desolation!
Encouraged by the approval of famous scientists, who have examined and testified to the correctness and beauty of this first phase of the moon, Mr. Harrison has completed a second phase, and is at work on the remaining pictures, which are in various stages of progression.
Among the prominent features represented as seen on the telescopic moon at the first quarter may be mentioned the Mare Crisium, one of the darkest of all the regularly bordered mares or dark plains. Crisium shows a surface of a gray tint tinged with green. At times it is curiously dotted and streaked with light. The floor is traversed by ridges crossing each other and throwing up small peaks. At the first quarter appears Messier, on the terminator of the three-days-old crescent. Messier is a fine crater-plain, nine miles in diameter, inclosed by a bright mountain-wall. To the southeast rise the walls of Catharina, in some places reaching a height of sixteen thousand feet above the interior plain, which, under the highest magnifying power, shows a surface broken up into mounds, ridges, hills, and craterlets.
Lying to the northwest appears the Mare Fœcunditatis, the largest of the western mares or sea-beds, covering an area of one hundred and sixty thousand square miles, and penetrating, in bay-like indentations, into the mountain-ranges southward. Mare Tranquillitatis and Serenitatis, the latter one of the most prominent gray plains seen at the first quarter. The entire central portion of this mare shows a decided light-green tinge.
At the last quarter the most striking feature is Copernicus, the grandest ring-plain on the northern quadrant, and one of the most instructive. Its vast walls rise nearly twelve thousand feet above the level of the plateau, showing fifty magnificent peaks that shine at certain seasons like a crown of pearls on a radiant background. The central cones attain a height of nearly three thousand feet. On the inner side the walls fall abruptly in terraces to the floor, while, without, they slope gradually, and are broken into confused ridges, spreading away from their bases into hill and mountain chains.
Aristarchus, a brilliant ring-plain, is also visible at the last quarter; its broad, terraced walls rise twenty-six hundred feet above the moon's surface, and seven thousand five hundred above its own interior floor, nearly in the center of which stand two peaks and a small crater, the central peak being the most brilliant point visible on the moon. Among the bays, so called, seen on this quarter, is the Sinus Iridum, a dark, semicircular level, bordered by the magnificent cliffs of one of the most stupendous highlands of the moon, whose crest sends up at certain points towering peaks from fifteen to twenty thousand feet above the level of the dark plain.
The Mare Imbrium, also lying in the north quadrant, is the largest of the dark ring-plains of the moon. The lunar Carpathian and Apennine ranges bound it on the south, the Caucasus and Alps on the west, and on the north the lofty highlands of Plato and the Sinus Iridum. It has a length of seven hundred and fifty miles, and a breadth of six hundred and seventy-eight.
One of the most wonderful and mysterious features of the moon, and seen on the southern quadrant, is Tycho, the center of the principal streak system. From its mountain-walled plain issue streams of radiance like rivers of silver; some of these "rilles" flow for a length of a thousand miles. The southern portion of the moon is a mass of old craters, ring-plains, valleys, hills, and ridges; with its radiant streak system and diversity of formations it is the most interesting part of the lunar surface.
When completed, this series of paintings will present not only a worn-out world in miniature, but, if one may credit the great astronomers of our day, the painted prophecy of the far-off future of our own earth, when it shall have cooled off, and all the bustling, battling throngs of humanity be as its own clay!