The Music of the Spheres/Chapter 6

From Wikisource
Jump to navigation Jump to search
4394418The Music of the Spheres — Chapter VI.Florence Armstrong Grondal



Leo, the Lion

About 9 o'clock on the 8th of April, a large, bright sickle passes near the zenith. This sickle lies just south of the Big Dipper and is a clearly defined figure among the other designs which decorate the sky during the early spring.

Truly, this is a strange symbol to see emblazoned in the heavens; has it too a story? Indeed, yes; this cluster of stars is the Sickle of Leo and lies on the head of the fierce Nemean lion which came from the moon and which was later killed by Hercules and transferred to the starry sky. The lion's head rests in the curve of the figure; his shaggy neck on the short straight line and his heart beneath the bright star on the end.

Not far away lies the rest of this brave creature with another bright star on the tuft of his tail. Drawn together, the sickle and the triangle now suggest a very dignified lion, although in the old star atlases he is pictured as a very ferocious lion transfixed in a moment of action.

Note well this curious sickle-shaped figure beneath the bowl of the Big Dipper. We will take this figure just at present, as a leader, while calling attention to the oddly assorted but interestingly assembled groups of stars which follow Leo in a widely curved path near the dome of the heavens, from the far northeast to the far northwest.

These groups appear one by one like a line of floats pulled up over the horizon; then drawn in a glittering procession toward the west. Each evening they appear farther along in their journey westward,—a pageant far distant in the darkness yet visible by the gleaming of its lights.

Closely following Leo, the Leader, is a representation in faint golden starlight of Queen Berenice's Hair; next the lovely orange-yellow star, Arcturus, on the dim kite-shaped figure of Boötes, the Herdsman; then a crown of star gems which belonged to Ariadne, daughter of an ancient king of Crete; a huge giant called Hercules; the golden Lyre with which Apollo raised the walls of Troy and Orpheus charmed the souls in Hades; and last, but not least, a large and beautiful Cross.

The Lion disappears behind the western "bulge of the world" during the early summer, although the last of the procession, the great Cross borne on the back of Cygnus, the Swan, does not even reach the meridian—the line midway between east and west—until September. Some of these groups are also seen later than October, but at that time their splendor is dimmed by the gorgeous winter constellations in the southeast.

According to the classic legend of the Greeks, Leo was the celebrated Nemean Lion which Hercules killed as the first of the Twelve Labors which were imposed upon him by his cousin Eurystheus, who was king of the Perseidæ only through priority of birth. This lion was the largest and fiercest lion in the world with a skin so invulnerable that no arrow had ever succeeded in even denting it. The huge beast was also so rapacious that it was fast annihilating all the inhabitants of Nemea, which was the ancient name of the deep valley of Argolis. Hercules had no trouble in tracking the lion through the valley, which was only two or three miles long and half a mile broad, and easily found its den. Rushing in, he barricaded the opening, grasped the lion by the throat and after a terrific struggle, crushed the beast in his arms. Ever after he wore the tough, impenetrable skin as a covering for his own defense. The Nemean games, one of the national festivals of the Greeks, are believed to have been founded by Hercules after his victory over the Nemean lion. There is some evidence that there was a lion traced among the stars before the time of Hercules, but, if so, the Greeks erased the impression and substituted their own lion in its stead.

Leo, the Nemean lion in stars, is seen at his best during the early evenings of March, April, May and June, although he makes his first appearance on the 4th of March when, just as the sun sets in the west, his tail rises above the eastern horizon. In April he is at his highest point in his path across the sky, lying just to the south and below the bowl of the Big Dipper.

On the end of the handle of the Sickle shines Regulus, also called Cor Leonis which means "The Heart of the Lion." Regulus sends out 300 times as much light as our sun, but is so far away that it takes 99 years for its light to reach us. This star rises in the northeast at twilight on the 15th of February and crosses the meridian at 8 o'clock on April 23rd.

One generally thinks of stars as being bright and gay, but Regulus has a companion which is somber and so unusual in its appearance as compared with other stars that it was described by Winlock, its discoverer, as if "steeped in indigo." Later it was found that this oddly colored star also has a companion which makes Regulus a triple star.

The second star above Regulus is also interesting. This star is a beautiful double described in such refreshing terms as "golden-orange" and "bronze-green." It may be seen in a medium sized telescope. Later we will become acquainted with a wonderful red star which also has a green companion. Such combinations are most amazing to gaze upon.

The second brightest star adorning Leo is Denebola, which flashes on the end of his tail. Denebola is 10 times as bright as our sun and is 25 light years away. Since Regulus, on the heart of the Lion, is 99 light years distant and Denebola, on the tail of the Lion, is only 25 light years, science has certainly played havoc with the poor Nemean lion. Proctor tells us that Coma Berenices (Berenice's Hair) was originally the tuft of the tail of the lion when the constellation was pictured in the maps as being more extended. This was quite an appropriate place for the sparkles and gleams of these fine, tiny stars. It is likely that it would have still been the tuft on the Lion's tail if a clever Alexandrian astronomer had not found it necessary to use his wits quickly and call it Berenice's Hair to please the vanity of an Egyptian Queen.

The apparent center for the November meteors, or "shooting stars," which appear about the 15th of the month, are within the curve of the Sickle of Leo near the star Gamma.

The apparent paths of shooting stars when projected backward meet at a point called the radiant point. It looks from the diagram as if these meteors all came from one fixed place in the sky but the effect would also be the same if we saw, for instance, seventeen trains racing along seventeen tracks laid parallel across a desert from a point on the distant horizon. They would all seem to start from this point and widen out as they approached the observer, the effect in perspective, the widening apart from a point, being the same in the case of the meteors speeding along parallel lines in space. We see only those meteors, of course, which become caught and ignited in the atmosphere surrounding the earth and which streak down the sky all aflame; the rest pass on their way, invisible. Of this more will be said later under the heading of "Comets and Meteors."

The "Leonids," as these November meteors are called, are only seen in the early morning hours on the 15th of November, while the "Andromids," which have their radiant point in Andromeda, are only seen in the early part of the evening on the 24th of November.

The famous Leonid meteors of 1833 dropped down so fast and thick that it seemed that all the stars in the heavens were falling down on the earth. This unique spectacle occurred again in 1866, and records show that, for a thousand years back, at intervals of every 33 years, we have been visited by such a "star shower." The first disappointment came in 1899, just as the general public, probably for the first time, was looking forward to it with a great deal of pleasurable anticipation. Will we again be disappointed in 1932? Although the earth passes across the pathway of these meteors every year, it is believed that along a certain section of the pathway the meteors are strung in thick profusion. It is through such a portion, literally studded with the fragments, that the earth rolls every 33 years, although it is not known for a certainty why, after all these years, we failed to see a display in 1899.

A small "dark" constellation called Cancer, the Crab, lies just in front of Leo, the Lion. Although this constellation has been pointed out since very ancient times, and holds an important position in the zodiac, it does not contain a single conspicuous star and could scarcely be located in the sky, were it not for a faintly shining spot of light about the size of the Pleiades. This spot of light is a coarse cluster of 7th and 8th magnitude stars, resolvable by an opera-glass and easily located by a little star on either side. In the mythology of Greece, this constellation represents the gigantic sea-crab which Juno sent to bite the toes of Hercules when he was struggling in the marshes with the hundred-headed hydra. Naturally, Hercules stamped his foot down on the petty annoyance, which so offended Juno that she set the creature among the stars.

It is the "misty spot," however, that has always attracted the eyes of men. The Chaldeans thought that the dim light came from a hole in the floor of heaven, and that it could be no other than the "gate of men" through which souls descended into human bodies. It has also been regarded as the Manger in which Christ was born and the stars on either side were called Aselli, or Little Asses. The "Manger" is now known to hold 363 telescopic stars, and is historically interesting because it afforded one of the earliest telescopic proofs that there were hosts of stars in the heavens besides those visible to the unaided eye. Galileo, who first resolved its light into stars, was able to count forty small stars in this spot, and his telescope was no better than the field-glass of today, if we may indeed make such a comparison.

In ancient times, Præsepe, the Manger, was an infallible weather sign, for if there was the slightest moisture in the air, its faint light was invisible. If the moisture was not sufficient to also obscure the two stars on either side, only light showers of rain might be expected, but if the two stars were also hidden, there would be a very bad storm. If the two stars and the Manger were all three seen clearly, one could depend on the weather not to spoil any plans for that particular evening.

"When shine the Bears, and 'twixt the asses seen,
though faint, their Manger, ocean proves serene."
Idylliums of Theocritus (Fawke's Trans.)

In the days of Aratus, 270 B. C., this advice as to how to judge the weather by means of the tiny cloud on the back of Cancer, the Crab, was taken so seriously that he gave it in quite extensive detail in his poem Phenomena:

"Watch, too, the Manger. Like a faint mist in the far North it plays the guide between Cancer. Around it are borne two faintly gleaming stars, not very far apart, nor very near but distant to the view a cubit's length, one on the North, while the other looks toward the South. They are called the Asses and between them is the Manger. On a sudden when all the sky is clear, the Manger wholly disappears, while all the stars that go on either side seem drawn to one another: not slight then is the storm, with which the fields are deluged. If the Manger darken and both stars remain unaltered, they herald rain. But if the Ass to the North of the Manger shine feebly through a faint mist, while the Southern Ass is gleaming bright, expect a wind from the South: but if in turn the Southern Ass is cloudy and the Northern bright, watch for the North Wind."

English trans., by G. R. Mair.

In English folklore, Præsepe is called the Beehive, although this name was likely given it after telescopes were invented and it was seen that the dim light was resolved into a multitude of little flecks, like a hive of golden bees.

Præsepe passes the meridian about 9 P. M. on March 15th or 2 o'clock A. M. on the morning of January 1st. It is best seen on a clear night when the moon is absent from the sky, and a glass of any kind will make it more interesting.

Both the Crab and the Hydra, who also has a constellation in the sky, are quaint ways of commemorating the adventures of Hercules, but his fierce Nemean lion is the most important just at this instant, so on with the line of floats!

Berenice's Hair

The name of Coma Berenices,—Berenice's Hair,—was derived from an Egyptian fable which dates back as far as the 3rd century B. C. Before this time, the constellation was the tuft on the tail of Leo, the Lion. Thus we find Præsepe, an interesting cluster of stars, just in front of Leo, and Coma Berenices, an equally interesting cluster, just behind him. These two clusters are among the very few clusters that may be located with the unaided eye.

Coma Berenices is most clearly visible on a dark night almost overhead in the early evenings of May. With an effect like 90 minute stars scattered on velvet, these stars are quite unlike anything else in the heavens that is visible without optical aid.

Astronomers have found that many of the stars in this constellation are of a delicate lilac color. These lilac stars are often the companions of other stars, forming such lovely color combinations as orange and lilac, white and lilac and blue and lilac, although these double stars are not easy to locate in this thick sprinkling of stars without the help of a telescope with an equatorial mounting and graduated circles. One wonders what it would be like to have a lilac sun as a source of light, and what would be the psychological reaction on generations of beings brought up under pale lights, mauve mists and shadowy purples. There seems to be a slight difference in even the general characteristics of our earthly folks when those who live in a land of perpetual sunshine are compared with those who live in a city smothered in murky fogs.

The telescope has also discovered in Coma Berenices the rare sight of over 100 nebulæ drawn together in a close group. We say a "close group," but these nebulæ only look crowded to us because they lie at such an unthinkable distance from our solar system.

An ancient story, current 246 B. C., relates that this constellation was named after the beautiful hair of Berenice, Queen of Euergetes, one of the Ptolemies of Egypt. The husband of this Queen had gone to Assyria on a dangerous campaign and, grieving over his delay in returning, the Queen vowed to cut off her long locks of hair and consecrate it to the gods in the temple of Venus, if he might only come back to Egypt safe and victorious.

Not long after this great sacrifice had been determined upon, Euergetes returned and the Queen cut off her tresses and hung them in the temple of the goddess. But that same night the hair was stolen! Conon, the royal astronomer of Alexandria, however, in his goodness of heart and thinking to protect the guardians of the temple from their majesties' displeasure, stepped forward and declared that Venus had so appreciated such love as possessed by this faithful Queen that she had caught up the strands of beautiful hair and laid them in the heavens. All looked toward the spot at which the astronomer pointed, and, sure enough, there lay near Leo a group of fine stars which shone like the mist on a woman's hair! Thus the guardians were saved, the husband appeased and the astounded Queen Berenice flattered and satisfied.

The Lion, Leo, however, was now obliged to change the position of his tail and instead of having it extended and brightened with this sprinkling of delicate stars, he was forced to draw it back and curl it behind the light of Denebola, where it has since remained.

Boötes, the Herdsman

The brilliant golden-yellow star, Arcturus, has always been a favorite among star-gazers. This star hangs like a great globe of tinted light from the end of a curve drawn from the Big Dipper's handle and is one of the first stars to appear during the summer evenings.

Two earthly honors have been given Arcturus which are well worth noting. In the excess of their great admiration, the Egyptian people in ancient times oriented huge temples to it at the cost of tremendous labor; it was also given special mention in the Bible.

Up near the Arctic circle, this lovely star never sets, but travels in a wide circular path above the horizon. Allen remarks on its use as timepiece for the seal-netters during the night fishing in December and January. The netters judge the time by the position of the star on the four points of the compass, in much the same manner that the Big Dipper is used for a clock as it swings around the pole. The heavens would appear rather strange to us as viewed from the far north for Polaris would rest almost at the zenith and the Big Dipper with its handle weighted down by Arcturus, would seem to encircle the sky above the earth on an unfamiliar pathway.

Boötes, the constellation in which Arcturus lies, is usually described as forming a kite-shaped figure of stars, which though faint, covers a great deal of sky. Boötes, as mentioned before, was a herdsman who invented the plow, and as a reward for this ingenious method of tilling the soil, was raised to a position below the stars of the Big Dipper. But according to another story, Boötes represents Arcas, the son of Callisto, whom Juno so cruelly turned into a bear. In modern days this legend seems to have been given preference for, during the seventeenth century, Helvetius invented the Hunting Dogs, the constellation of Canes Venatici, and the huge figure of Boötes has since been usually pictured on the star maps as holding two lively dogs in leash. These Dogs are interposed between Boötes and Ursa Major. Although the Hunting Dogs have no mythology, the two constellations are thus united in a common picture and Boötes and his dogs are said to be chasing the Bear.

In Ovid's version of the legend, the hunter was placed in the sky just as he was and not first metamorphosed into a bear and hung on the Pole Star as Ursa Minor. Not recognizing his mother in the form of Ursa Major, Boötes keeps on pursuing her in an eternal chase about the Pole. He is thus often called "The Watcher of the Bear" or "The Bear Driver." Those who choose to consider Callisto's son, Areas, as having been metamorphosed into a bear and hung on the pole of the heavens may then consider Boötes as representing the herdsman who invented the plow.

The two Hunting Dogs, "Asterion" and "Chara," now held enchained by Boötes, form the constellation Canes Venatici, which lies just below the handle of the Big Dipper and above Arcturus and Berenice's Hair. The collar of the hunting dog Chara is marked by the star Cor Carolli, which means "Charles' Heart" and was named in memory of Charles I by Halley, the English astronomer, on the suggestion of the Court Physician, Sir Charles Scarborough.This star is an attractive double as viewed in a small telescope with the delicate colorings of "flushed white and lilac." On the head of Asterion lies the famous whirlpool nebula, although this may only be seen in a large telescope. This nebula has its great arms of nebulous material flung widely into space and looks as if it were whirling rapidly about, but the motion, if any, is too slow for us really to see. With a few exceptions most of the spiral nebulæ are so very distant that they may only be seen through a very large telescope, but next to the stars, they are the most abundant objects in all the sky and are of great interest to astronomers.

Arcturus, the beautiful first magnitude star which glows so conspicuously in the constellation of Boötes, is, however, the main source of interest in these star groups. The star is popular for its appearance alone, for it is large and richly golden, and always easily located, but it is also of interest in a scientific way, for it has been found to be an extremely huge and glorious sun. Our sun placed at the same distance—145 millions of millions of miles—would shine as a faint and almost invisible star, yet Arcturus is so much larger than our sun that it drifts across our sky like a bowl of light.

Arcturus is not only one of the largest but it is also one of the swiftest moving stars in the heavens. It moves so swiftly that it covers 100 miles in every second. This speed has caused it to be labeled a "runaway star." Although this star shoots through space at such an incredible rate of speed it has taken it 800 years to describe a space (as seen by our eyes) equal to the apparent diameter of the moon. This may give the reader some slight realization of the vast distance which separates us from Arcturus. But astronomers write it this way—"It has taken only 800 years for Arcturus to describe a space equal to the apparent diameter of the moon," for the stars are so very distant that most of them do not seem to change their places in the heavens even in the course of many thousands of years.

Amazing as the speed of Arcturus appeared to astronomers, they later discovered a star of the 8th magnitude in the southern hemisphere with even a greater proper motion. This star has moved the distance of the diameter of the moon in 220 years, which means that it moves over a hundred times faster than the average star. But the late Professor Barnard of the Yerkes Observatory had the distinction of discovering a star with the largest proper motion known. The average star does not exceed one minute of arc in a thousand years but Professor Barnard's "runaway star" has the amazing proper motion of 10.3 seconds a year. In that length of time it travels twice as far as the average star does in a century!

Scientists accomplish many wonderful, and most remarkable, deeds. Even the heroes who lived in the vivid minds of the ancient peoples dwindle into insignificance beside these men with their calm patience and brilliant seeking minds.

"These mathematic men have thoughts that march
From sphere to sphere and measure out the blue
Of infinite space like roods of garden ground."

Professor Michelson has now invented a new method of measuring the angular diameter of the more distant stars. This is by means of an instrument called the "interferometer" which is attached to the 100-inch reflector of the Mount Wilson Observatory. Measurements of the angular diameter of Arcturus with the interferometer combined with the knowledge of its distance give us the astounding size of 19,000,000 miles for the diameter of this huge sun.

Henderson, in 1840, was the first astronomer to make a successful measurement of the distance to a star. The trigonometric method such as surveyors use to find the distance to the far side of a river was employed for this and with a baseline and angles he reached out and touched the nearest stars.

The baseline of a triangle whose apex touched a star which lay millions of millions of miles away would have to be very long indeed—and a very delicate and difficult task to handle it. Where in the world could one find such a baseline? Certainly not on the earth! A line extending from one side to the other of our earth would not even be as large as a point of light as seen from a star. Indeed when the moon was measured, and the moon lies only 240,000 miles away, astronomers used a baseline which extended from America all the way to France. The exceedingly clever idea of taking the earth's orbit as a baseline then suggested itself, and focussing upon a star at an interval of six months when the earth is at the two ends of the diameter of its immense orbit around the sun. The angle between the baseline and the line of sight to the star may be noted in the summertime, for instance, and then again in the winter. The shift of the star on the heavens caused by the observer changing his place from one side of the sun to the other gives the parallax angle of the star, which is the angle between the two sight lines of the observer where they meet at the star. If the star is distant more than 500 billion miles this shift cannot be measured with any confidence for at 900 or 1000 billion miles, the star ceases to show any displacement. When a star is near enough to be measured by this trigonometric method it seems to describe a minute ellipse "like a reflection of the ellipse of the earth's orbit." If it lies so far in space that it does not seem to change its position even when viewed from stations on either side of the earth's orbit, its distance may never be measured by using the diameter of the earth's orbit as a baseline.

Even the near stars are so very distant that their displacement is almost imperceptible. The parallax (or the apparent angular shifting caused by the changed position of the observer) of Alpha Centauri, our nearest star, would have, says Professor Moulton, the same difference in direction as a point of light 11 miles from the observer viewed with one eye and then the other, with the difficulties of observation extended over several months.

But to return to Arcturus. This beautiful golden star is called the "harbinger of spring" because it rises on the first of March just as the flowers of this season are awakening along the brooks and hillsides. Watch for it about 8 P. M. just a little north of east. At this point it is at its very best for the thickened atmosphere near the horizon fires the orange-yellow to a molten rose, while the flickering and the dancing causes burning waves of crimson, sparks of opal and glints of gold. It reaches the meridian June 8th about 9 P. M. but its eager, splintering light is now calmed to a steady glow and the star hangs like a golden lamp above the world. From July to December, this splendid star floats lower and lower through the western part of the heavens until it touches the horizon in the northwest and disappears.

The Northern Crown

The Northern Crown really looks like a crown. Its outline is easily traced, although its stars are delicate with the exception of one which is much larger and brighter than the others. It closely follows Arcturus and is best seen during the early evenings of July when it is floating high in the dome of the heavens, a most fascinating star figure.

Long ago, in some of the old countries, people saw in this "Crown" the likeness to a broken plate held out by a beggar to receive alms; the Pawnee Indians imagined it a camp circle of warriors sitting in council around their camp fire and that the bright star was a servant preparing a feast over the fire; the Australian natives called it the "boomerang," but in Greek mythology this is the crown which Bacchus gave the beautiful Ariadne after she had been deserted by Theseus, King of Athens, on the island of Naxos which lay far out to sea.

According to a later legend, from which the Crown obtained its name, a yearly tribute of seven youths and maidens was exacted from the Athenians by the tyrant Minos, King of the Island of Crete. These Athenian captives were then rowed over from Greece to Crete and confined in a labyrinth as a feast for a ferocious Minotaur. This labyrinth had been constructed by Dædalus, a most ingenious artist and artificer, who had so perfected the intricate maze of passageways that neither the Minotaur, nor any of his victims, could possibly escape.

Theseus, son of Ægeus, the king of Athens, grieved deeply at the fate of so many innocent sufferers, and thinking that he might be able to overcome the monster, bravely offered himself as one of the seven youths. When Ariadne, daughter of the wicked King Minos, saw the handsome Prince arrive among those to be sacrificed, she was filled with love and pity and risked her own life by secretly furnishing him with a strong sword and a long thread. Theseus then attacked the Minotaur and slew him, afterwards extricating himself from the difficult windings of the labyrinth by means of the thread. He and Ariadne then slipped down to his vessel which had remained anchored in the harbor and set sail for Athens.

On his homeward journey the goddess Minerva appeared to Theseus and told him that he must leave Ariadne at Naxos, an island celebrated for its vineyards, for the Fates had decreed that she should not go with him to Athens. Such barbarous conduct on the part of Theseus must have been past all understanding to poor Ariadne. Ræ has painted a very beautiful picture of her as she sits by the rocks on the sea-shore sadly gazing out to sea, for she was a very sweet girl and not at all like her wicked father. But Theseus suffered also for his seemingly heartless desertion, for he had promised his father, Ægeus, that if he succeeded in subduing the Minotaur he would exchange his black sail for a white one. With one thing and another happening, Theseus forgot to change his sail, and the poor old man watching the black wing loom in the distance, supposed his son to be lost, and threw himself into the sea. This sea was henceforth called the Ægean Sea in memory of the tragic fate of Ægeus. In the meantime Bacchus, the God of the Vineyards, came along decked in ivy and vine leaves, and discovered the forsaken Ariadne asleep on a rock, worn out with sorrow and weeping. The god was so captivated by the beauty of the Cretan maid that he did everything in his power to make her forget her unhappiness, even marrying her and promising at her death to give her a place among the gods. He then suspended her wedding crown in the sky, where it still hangs, although its jewels have grown so large that they resemble stars. These stars are now called the "Northern Crown" though they are really

"A brilliant sign of the lost Ariadne."

Spenser pointing them out in his Faerie Queene says

"Look! how the crowne which Ariadne wore
Upon her ivory forehead—
—is unto the starres an ornament,
Which round her move in order excellent."

Ariadne's Crown rests about 20 degrees east of Arcturus and may be easily seen in the east just after sunset during the early spring, about the 8th of April, but it is at its best during the early evenings of July when it is almost overhead.

Alphecca, "the bright one," also called "The Pearl," marks the radiant point of a shower of meteors called the Coronids. This shower occurs while the constellation is traveling between the east and the zenith, being visible from April 12th to June 20th.

The Crown remains in view from April until late October, then disappears between the west and northwest. It lies concealed throughout the winter, then rises in the direct northeast in the early spring, its jewels sparkling as if they had been encased in a winter's casket of snow.

This beautiful little constellation is designated on the maps as Corona Borealis. The "Northern Crown" and "Ariadne's Crown" are only popular names.

Hercules, the Giant

An astronomical work of Eudoxus, dated about 370 B. C., but based upon observations made probably by the Chaldeans fifteen centuries before, was versified in a poem of 732 verses called "Phenomena" by Aratus, the court poet of Macedonia, who wrote about a century after Eudoxus' time. Aratus mentions this constellation of Hercules as being of immemorial antiquity and describes it as a figure of a man in sorrow with his hands upraised and stretched "one this way and one that, a fathom's length." In the early days of the world's history it was called "The Kneeler" although even this was not supposed to be its original name. Aratus says—

"Right there in its orbit wheels a Phantom form, like to a man that strives at a task. That sign no man knows how to read clearly, nor on what task he is bent, but simply calls him On His Knees."

Trans. by G. R. Mair.

"On His Knees" was given the name of the hero Hercules when the Greeks placed their heroes and divinities among the stars, but his pictures in the modern maps do not seem to accord with the description of his posture in this ancient poem. His foot now rests upon Draco, the Sky Dragon, which probably is here imagined as old Laden, the sleepless dragon which once coiled around the tree of golden apples.

Hercules, the great grandson of Perseus, was the greatest of all the heroes. He possessed every high quality of mind and character and was endowed with such great physical strength that his life was filled with constant adventure. Armed with a huge club, he performed the most remarkable deeds, the most wonderful of these being his "Twelve Labors." Some of these labors or adventures were so thrilling that the Greeks named constellations in honor of them as well as of the hero, and they have ever since been proverbs among men. There are many allusions to these throughout literature—

Leo, who leads the zenith constellations across the sky, was the same ferocious lion which Hercules encountered and killed in the valley of Nemea; he also killed the Crab now in Cancer, and the hundred-headed Hydra whose constellation is seen in the south from March to June. Some writers see in Sagitta, the Arrow; Aquila and Cygnus, the Birds; Draco, the Dragon and other constellations, memorials of the adventures of Hercules.

This huge giant gave promise of a career while very young. When no more than eight months old, two monstrous snakes appeared and pushed their hissing heads between the bars of his cradle. Springing to his feet, he seized the reptiles by their necks, strangled them and threw them dead at the feet of his terror-stricken parents.

"The mighty infant showed them to his sire,
And smil'd to see the wreathing snakes expire;"
Idylliums of Theocritus (Fawke's Trans.)

When Hercules grew to manhood his cousin, who ruled the Perseidæ, commanded him to perform ten difficult tasks, which were later increased to twelve. Hercules was at first unwilling to obey but the oracle at Delphi informed him that he would become an immortal hero if he performed the tasks, and afterwards be given a just reward. For a while Hercules was so despondent that he eventually became mad, but finally throwing off his depression, he accomplished all he set out to do with such cleverness and foresight and with exhibitions of such amazing strength, that not only did the gods carry him up to Mount Olympus after his death but gave him as a wife the lovely cupbearer, Hebe. His gigantic figure is now among the stars and many of the creatures in his adventures have been placed far above the earth in honored positions in the heavens. Let us now go back for a moment and review some of these awe-inspiring accomplishments of Hercules.

The lion and the hydra have already been mentioned. The watersnake was particularly difficult to kill for it possessed the distressing faculty of being able to immediately grow two living heads in the place of each one destroyed, thus increasing not only the snake but the number of poisonous fangs. This seemingly insurmountable difficulty was finally overcome when Hercules thought of searing each stump with a hot iron as soon as it was severed, thus killing the root from which the head was born. As seen on his constellation in the sky, this watersnake is more conspicuous for length than for his number of heads, for his faint starry outline covers one-fourth of the southern heavens and takes four months in passing any one place. It was during the struggle with this creature that Juno induced the crab to crawl out of the swamp and seize the mighty giant's toes, afterward placing the crab on the Dark Sign, Cancer, which lies just west of Leo.

The eleventh Labor of Hercules was the obtaining of the three golden apples from the Garden of the Hesperides. The location of these gardens, according to most versions of the story, was to the west of Mount Atlas where this most rare and delightful tree was guarded by a dragon and the four nieces of Atlas. Atlas, who knew best where to find the apples, offered to obtain them for Hercules if he would hold up the heavens while he was gone. Nothing daunted Hercules, so,

"The wearied Atlas he relieved,
His arm the starry realms upheaved,
And propped the Gods above."

In the meantime Atlas went to the garden and got the apples from his nieces. But according to another myth, Hercules went himself and stole the apples, after slaying the dragon that guarded them. It is to be noted that in the constellations Hercules has been placed in a decidedly uncomfortable position so that he might rest his foot upon the Sky Dragon, Draco—so perhaps Draco, after all, was the monster that was wound around that wondrous apple tree.

There is also a possibility that the sixth Labor of Hercules has been memorialized in the sky although the weight of evidence is against it. In his sixth Labor, Hercules destroyed the cruel carnivorous birds with the arrows he had dipped in the blood of the poisonous hydra. These birds, which had brazen wings, beaks and claws, hovered over the stagnant waters of Lake Stymphalus, in Arcadia, and ravaged all the surrounding country. This praiseworthy deed may have been represented in the sky by the "bird" constellations, Cygnus, Lyra and Aquila, which hover near the stream of the Milky Way, and in the little arrow Sagitta, which lies not far away, but it is more than likely, according to the majority of the myths, that these constellations were named in honor of other things rather than to commemorate the deeds of Hercules.

Among other exploits which illustrate the unrivaled prowess of this hero, are his battles with giants, monsters and centaurs; catching Diana's brazen-footed stag by driving it deep into a snowdrift in the distant northland; obtaining the girdle of Hippolyta, Queen of the Amazons, in the land of women; capturing boars, bulls, mares and even bringing from the infernal regions the three-headed dog Cerberus.

The greatest demonstration of his strength, aside from the time that he upheld the heavens for Atlas, is reported by the historian Pliny. According to the myth which Pliny relates, Hercules had rent asunder the rocks which had previously divided the Mediterranean from the ocean; although another legend takes the opposite view and asserts that he had narrowed the strait in order to exclude the sea-monsters which had hitherto forced their way in from the ocean. This gateway, known as the "Pillars of Hercules," consists of two promontories which bounded the western horizon of the then known world. The promontory on the northern side of the straits is now called the "Rock of Gibraltar."

Hercules one day donned a tunic that had been steeped in the blood of a Centaur which he had slain with a poisoned arrow. To escape the terrible torture, he erected a funeral pyre on Mount Etna, lay down on his lion's skin and set the pyre on fire. Amid peals of thunder Jupiter descended in his chariot and carried the hero to Mount Olympus where he was given his promised reward.

"High o'er the hollow clouds the coursers fly,
And lodged the hero in the starry sky."

As seen in the sky, Hercules kneels on Draco, the Dragon, with his head lying downward near the head of the giant Ophiuchus. These two giants cover a vast amount of sky space although neither one have very bright stars. Although Hercules rests inactive, Ophiuchus, one notes, is busily engaged, for his limbs are enfolded by the scaly body of a huge serpent

"his right hand, its writhing tail, he grasps,
Its swelling neck, his left hand securely clasps,
The reptile rears its crested head on high
Reaching the seven-starred Crown in northern sky."

In the meantime

"His feet stamp Scorpio down, enormous beast,
Crushing the monster's eye and plated breast."

And we gaze with admiration as Aratus describes this struggle which seems by all odds to be against the giant.

Ophiuchus perpetuates the memory of Æsculapius, father of medicine. He and his serpent, as seen in the sky, are exceedingly hard to trace but men also sought to do him honor on earth by erecting temples in which he was worshiped. The brightest star in the constellation of Ophiuchus, the Serpent Bearer, is Ras Alhague, although this name has gone entirely out of use and the star is generally designated as α Ophiuchi. This star lies on the head of Ophiuchus which is about three-quarters of the way up from the horizon to the zenith, when on the meridian. It rises a little north of east, appearing When the sun sets on the 14th of May, and requiring 6 hours and 46 minutes to reach the line midway between east and west. Ras Algethi (α Herculis), a beautiful orange colored star on the head of Hercules, is usually noted in connection with Ras Alhague, since they stand rather isolated only about 6 degrees apart. (The distance between the "Pointers" on the outer side of the Big Dipper is equal to 5 degrees.) When Ras Algethi and Ras Alhague are near the meridian, a glance of the eye beyond will meet two stars of the 2nd magnitude also not far apart. These are "The Dragon's Eyes," Alwaid and Etanin. Recalling that Hercules has his foot on the Dragon's head, that the head stars of the two giants' lie almost together, and the feet of the lower giant, Ophiuchus, are crushing down Scorpio, the Scorpion (a conspicuous anchor shaped constellation in the south), one has a fairly good idea of this section of the sky from the Pole Star to the horizon, when Ras Alhague and Ras Algethi are near the meridian. Since both Hercules and Ophiuchus have very large but also very inconspicuous constellations, it is well to keep them connected in some such manner.

In modern days the constellation of Hercules has gained in interest through observations made by the telescope. Unfortunately the ancients were not privileged to see its gayly colored double stars and its marvelously beautiful star cluster. Among the double stars, Young mentions an orange and blue, and a white and emerald green; the Rev. T. W. Webb points out one almost appetizingly attractive in its light apple green and cherry red while Serviss notes some charming combinations—orange and green, pale green and purple, light yellow and pale red—which may be seen with such meager assistance as an opera-glass. Serviss, by the way, has written a whole book on what may be seen in the sky with no greater aid than an opera-glass.

The star cluster in Hercules lies on the west side of the constellation, about one-third of the distance from the north end and not far from the figure of the Northern Crown. To the unaided eye, this cluster looks no more than a glimmering speck of light, but if a powerful telescope is trained upon it, it is resolved into a great cluster of stars. These stars, numbering into the thousands, are so packed together toward the center that they have been described as resembling "ice crystals in a snowball." From such a lovely blaze within the center another observer adds that "sprays of stars reach out in all directions like tendrils of a vine."

The stars counted on a photograph of the Hercules cluster which was taken by the great 60-inch reflector on Mount Wilson, number over 50,000! This telescope resolves even the solid glow of light at the center of the cluster into individual stars.

Sir Robert Ball in "Star-land" gives a good illustration of the appearance of a globular cluster of stars as seen in a large telescope. "I take a pepper-castor and on a sheet of white paper I begin
Photograph by Yerkes Observatory through 24-inch telescope. A photograph of the same star-cluster by the Mount Wilson Observatory through a 60-inch reflecting telescope is shown on page 2.

to shake out pepper until there is a little heap in the center and the other grains of pepper are scattered loosely about. Imagine that every one of those grains of pepper was to be transformed into a tiny electric light, and then you would have some idea of what a cluster of stars would look like when viewed through a telescope of sufficient power."

It was at one time thought that the cluster of Hercules might be a comparatively close cluster of small-sized suns, but Professor Shapley has lately discovered that the cluster is a very distant one; indeed it lies at such an exceedingly remote position in the realms of space that its parallax is slightly inferior to a 10,000th second of arc which corresponds to a little more than 36,000 light years. Thus it takes 36,000 light years for its light to reach us, for this light has to cross the unthinkable space of 220,000 billion miles!

Lyra, the Harp

Of the string of constellations twinkling high overhead during the spring and summer months, we have already mentioned Leo, the Lion; Berenice's Hair; Boötes with his golden Arcturus; the Northern Crown and the giant Hercules.

Next to Hercules, on the east, lies the constellation of Lyra, represented in legend as the sweet toned harp which belonged to Orpheus, son of the Muse Calliope. Orpheus inherited the love of music from his mother, and after the Sun-god had presented him with this wonderful harp, he played so delightfully that even trees, rocks and hills gathered around him to listen.

Treasuring the memory of such remarkable talents, the Greeks placed the instrument in the heavens at the edge of the Milky Way, where its framework was adorned by a group of stars, one of which is exceptionally bright, vividly blue and very beautiful. This blue star is called the "Harp Star," or Vega, by astronomers.

Vega rises in the far northeast in the early evenings during the first of May but during July and August it passes almost overhead.
Precessional Orbit of the Pole.
When near the rim of the northern horizon yellow and red fires dart out amidst the blue, but when high above in the dome of the sky, its color is pure and coldly blue, a decided contrast to the golden warmth of Arcturus, which lies not far to the west of it.

In consequence of the precession of the equinoxes, in less than 12,000 years Vega will be the nearest bright star to the pole; indeed it will be close enough to serve as our North Star. Then, instead of wandering from the far northeast to the far northwest, it will seem to stand in the north like a pale-blue pivot, while all the other stars will circle round it. Vega will hold this position for 3000 years. The constellation of Lyra and that of Hercules are of particular interest because they mark that part of the universe to which our sun is traveling at the rate of 12½ miles a second. Some day (in half a million years or so), this gorgeous sun, a hundred times more brilliant than our sun, may glow upon us as a near neighbor. In 12,000 years, when our north pole points to Vega, the great Cross with its bright stars Deneb and Albireo, will never set but will journey night after night in a small circle close about the celestial pole, Orion will climb over the zenith and the Milky Way in all its splendor will whirl about the north.

The principal figure formed by the stars of the constellation of Lyra has been best described as an "equilateral triangle balanced on the corner of a rhomboid." This figure is easily traced although all of these stars, with the exception of the brilliant blue one, are of no more than the 3rd or 4th magnitude.

To the average eye, the little star east of Vega, at the top of the triangle, appears a trifle elongated, but a sharp eye divides the star into two stars set very closely together. With a 3-inch telescope each of these stars is found to be double. This fourfold star in Lyra is sometimes referred to as a "double-double."

The third star, Lyræ, at the base of the "rhomboid" on the same side of the figure as Vega, is a variable with three small stars near it, forming a very pretty object with low power.

Also at the base of the rhomboid, between β and γ, one-third of the way from β, a small telescope will disclose a nebula which has assumed the shape of a ring, or at least it looks like a ring at this distance. There are various types of nebulæ, some, like the "planetary" and "spiral," having definite forms, others being as shapeless as a puff of vapor. Sometimes a planetary nebula has a star at its center, and again it appears hollow, like "a little smoke ring." It is then called a ring nebula. The most famous of these is the one found in Lyra.

On the 19th and 20th of April swift meteors, known as the Lyrids, radiate from the vicinity of this constellation, although the display is of interest rather than of any particular beauty.

The legend of this celestial harp, which is often hung by map artists around the neck of an eagle, is one of the most popular stories in mythology, and its very appearance in the heavens brings to mind the beautiful lovers, Orpheus and Eurydice. The harp was anciently represented as having been invented by Mercury, who gave it to his half-brother Apollo, the Sun-god, who later presented it to Orpheus, the son of a Muse.

Mercury, as an infant, gave promise of being a most remarkable god, for the very day that he was born, he climbed out of his cradle, wandered out of the lofty cavern of Cyllene and picked up a little tortoise that was crawling past the entrance. Gently pulling off the scoop-shaped shell, he bored neat holes along its edges, stretched dried tendons across its face, and wedged it firmly between two horns. His tiny hands then strayed across the strings, and he danced delightedly as the most delicious music issued from the shell.

"And this, whilst yet
Encradled, Hermes pierced and called it Lyre."

Mercury then went in and slept awhile, but when darkness came, he again slipped out of his cavern and ran over to the hillside to see what further adventure awaited him. Here he found the pasture of Apollo's cows, and looking the animals over, separated fifty of the best from the herd, wrapped their hoofs in
Photograph by Mount Wilson Observatory through the 100-inch Hooker telescope.

branches and drove them backwards into a large cave where he made a fire and sacrificed two of them to the twelve Gods (himself included).

The next day while Apollo was driving his sun-chariot over the slopes in the east, he noticed that a number of his favorite cows were missing. Investigating the matter, he traced the theft to this baby, who stood up in his cradle, looked the Sun-god in the face, and stoutly denied it; he even inquired in a naïve manner what sort of animals cows were. Too amazed for further words, Apollo picked him up, tucked him under his arm, and went straightway up Mount Olympus to Jupiter. Here the infant stood bravely in the midst of the assembly in the great Olympian Hall and with a look of injured innocence upon his face inquired, "How could I, still wrapped in swaddling clothes, drive away Apollo's herd? You well know that I was only born yesterday and have never crossed my mother's threshold." The gods, perfectly aware of his guilt, roared with laughter and loudly applauded. Even Jupiter smiled at the infant's cleverness and, presenting him with a winged silver cap and silver wings for his feet, told him to lead Apollo to the cave where he had driven the cattle. Seeing that further subterfuge was useless, Mercury laughed gleefully and handed Apollo his harp as a peace offering.

Apollo soon played divinely on the little harp and was altogether so pleased with the instrument that he gave Mercury entire charge of his flocks and herds, as he preferred to become famous as the God of Music. The Sun-god later gave the harp to Orpheus, and because a god had played upon it, it responded to the touch of this beautiful youth in tones so pure and joyous that even wild beasts were charmed, while birds swarmed about him in the air and sea-monsters came up to hear him from the bottom of the sea. The power of his music was so great that rushing torrents slacked their rapid course to listen to him, and once, while playing, he watched amazed as a whole forest marched up to a level place on a hill where it made a shade for a large assemblage of wild animals and the multitudes of birds who sat as if enchanted while he played.

This gay and happy musician had a lovely bride named Eurydice, daughter of the Sea-god Nereus, whom he fondly loved. One day while wandering in the fields, Eurydice was fatally bitten by a viper which lay concealed in the long grass. Orpheus filled the groves and valleys with his piteous lamentations and finally, unable to live without her any longer, he boldly walked into the cave that led to Pluto's realm, and braved the horrors of the steep, dark path which led to the lower world. After a difficult journey he arrived among the Shades, and wandered playing and singing among the admiring throng. The ancients claim that the power of his music arrested for a while the torments of the damned, that his "golden tones" seemed so heavenly in these gloomy depths that the stone of Sisyphus remained motionless, the Danaides stopped their wearisome task of pouring water through a sieve, and the Furies withheld their persecutions.

"E'en Tantalus ceased from trying to sip
The cup that flies from his arid lip."

Pluto was touched to unheard of softness and, as he granted Orpheus' plea that Eurydice be returned to him, "iron tears" rolled down the furrows of his cheeks. "But hold," said the crafty monarch, "there is one condition. If you once glance behind you to see if Eurydice is following, you must lose her again forever." Crashing chords of joyous triumph, Orpheus hurried up the rough pathway that led to the top of the world, but as he was about to pass the extreme limits of Hades and saw beyond him the opening where the sunlight reached in gently through the darkness, he grew afraid, and in order to convince himself that his beloved wife was really behind him, he turned suddenly around—only to see Eurydice, with her arms outstretched, floating slowly backwards into the drear, dead land below. The grief of Orpheus at this second loss was even more intense than before, and half-crazed with sorrow and remorse, the poor lad stumbled to the banks of the river Strymon, where he mourned for seven days with neither food nor drink. At last he wandered up into the mountains where he fell into the hands of wild, bacchanalian revelers and came to a violent end. At the intercession of Apollo and the Muses, the harp of Orpheus was placed among the stars while the youth himself was tenderly cared for and buried beneath the shadow of Mount Olympus.

Some mythologists, however, claim that Orpheus was changed into a swan and placed in the heavens as the constellation of Cygnus so that he might be near Lyra, the constellation of the Harp, although the Latin poet Ovid claims that "Cygnus" took its name from "Cycnus," a friend of Apollo's son Phæthon. It might seem strange, on the face of it, that a celebrated singer like Orpheus should be changed into a bird as lacking in song as the swan, but it should be remembered that the ancients believed that a dying swan sang very sweetly. At least we are quite certain that Lyra is the harp that Mercury invented, that the Sun-god endowed with a golden tone, and that Orpheus played upon when he held spellbound not only mankind, but beasts, rocks and trees.

This great Harp floats across the dome of the heavens on summer evenings with the blue jewel Vega blazing on its frame. Longfellow in "The Occultation of Orion" clearly visioned

"its celestial keys,
Its chords of air, its frets of fire."

It is easy to imagine that these twinkling chords still sigh and give forth strains of music, for an Æolian Harp is a harp that sings when a wind passes over its strings, and the music of such an instrument is of a drowsy, lulling quality which blends beautifully into dreams.

The Great Northern Cross

Just east of the Harp Star, in the center of the Milky Way, rests a cross of stars, clear and bright, as if a cross had really been placed there and then studded with five big stars.

During the month of May the Cross rises on its side (as viewed by an observer in the northern hemisphere), but it rests north and south as it reaches the zenith in midsummer. By December it has reached the slope in the west, and now assuming an upright position, descends majestically to the horizon. This descent is quite effective, especially at the moment when the pale orange star, which rests at its base, lightly touches a mountain range etched in the distance or the edge of a far-reaching plain. This 3rd magnitude star, Albireo, is a favorite with amateur astronomers, for it has a 5th magnitude companion star of the richest and most vivid greenish-blue. This lovely double star with its sharply contrasted colors may be seen to good advantage in a small telescope and vies in beauty with the famous three-colored star, Gamma Andromedæ.

Deneb, the brilliant white star at the head of the Cross, is a very distant sun but is so large that it shines forth brightly among our finest stars. It is estimated by astronomers as being at a much greater distance than the Harp Star, Vega, and Vega is distant about 232 millions of millions of miles!

In contrast to the huge sun that Deneb must be to shine so brightly at its great distance, there is a little star above the armpiece on the eastern side of the Cross, which is the nearest star to the earth that has yet been found, as seen from the northern hemisphere. This faint star is really a very tiny sun for nine more similar suns thrown into it and blazing as one big fire, would no more than equal our sun in brilliancy.

In the vicinity of 61 Cygni, is a large, mysterious, black spot visible on account of the glow of light from the densely packed stars of the Milky Way. This spot was first described as being "like a hole" and was curiously named "A Sack of Coals." Science later suggested that since we have dark suns perhaps we also have dark nebulæ and that such an object may be lying between us and those distant stars. The late E. E. Barnard of Yerkes Observatory made extensive studies of the distribution of nebular matter and he seems to have definitely proved the existence of "dark nebulæ." The black spots and "rifts" in the

Photograph by Mount Wilson Observatory through the 100-inch Hooker telescope.

Milky Way are now generally accepted to be dark nebulous matter which cuts out the light from the stellar regions behind them. Professor Barnard made many wonderful photographs of such dark spots and compiled a famous Catalogue of 182 Dark Markings in the sky. Dr. Hubble of the Mount Wilson Observatory found that in its normal state a nebula is dark rather than luminous. If a nebula shines it is because it is either illuminated by the light from the stars near it or because it is electrically excited in some way not clearly understood.

There is also a Cross on the Milky Way with a dark nebula beside it in a conspicuous position in the southern hemisphere, although there the cross is not quite as perfect as our cross in the north, for it is formed of only four bright stars instead of five. Even our cross is not quite perfect, for one star, the "diamond-studded nail" holding it together, is just a little out of line. Julia Ellen Rogers in "Earth and Sky" has said that her fingers fairly "itch to put it where it belongs." Imagine! And since she has so aptly expressed it, we now all feel that way.

This outlined figure of the great Northern Cross forms the basis of a constellation called Cygnus, the Swan. The bill of the Swan lies on Albireo, the double star at the foot of the Cross, while its wings curve gracefully back from the armpiece.

According to the story of Phaethon and Cycnus, Phaethon, after his hectic ride in the sun-chariot, fell a "charred fragment" into the river Eridanus. Jupiter's thunderbolt had hit its mark:

"And Phaethon caught in mid-career,
And hurled from sun to utter sunlessness,
Like a flame-bearded comet, with ghasthest hiss,
Fell headlong in the amazed Eridanus."

Phaethon's three sisters, the Heliades, wept so bitterly on the banks of the Eridanus that the compassionate gods changed them into poplar trees and their tears into amber. Ovid pictures their terrible grief—

"All the night long their mournful watch they keep,
And all the day stand round the tomb and weep."

Cycnus, Phaethon's friend, also grieved deeply and watched over the waters for many days. While watching thus his neck grew longer and longer until at last it became perfectly atrocious. The gods again looked down in pity, metamorphosed the youth into a swan and placed him on the river of the Milky Way.

"For Cycnus loved unhappy Phaethon,
And sung his loss in poplar groves alone,
Beneath the sister shades to soothe his grief,
Heaven heard his song and hastened his relief.
And changed to snowy plumes his hoary hair,
And winged his flight to sing aloft in air."

If this swan is really Cycnus it seems strange that he was not depicted as flying down the wavy line of Eridanus' stars instead of being placed over the silvery stream of the Milky Way, for the river Eridanus, into which Phaethon had fallen, was placed in the winter sky at the foot of Orion. This was supposed to console Apollo for the loss of his son. Perhaps the Swan is Orpheus, as some mythologists claim, carried up to the constellations to be near his well-loved harp. However, no matter which 'human' this long-necked bird is supposed to represent, we see its gigantic, graceful outlines sketched with star-like lightness beyond the stars of the Cross, and we see his snow-white wings extended and the orange light of Albireo shining on his beak, as he flies softly, head downward, along the misty river of stars.