an hour, scarcely evoked a note of admiration from men whose minds are sated with marvels. Like spoiled children, we take but little interest in our new toys. And then, we are in such a hurry that the present absorbs nearly all our attention. We have little spare time to reflect upon the past, little to bestow upon the future. Science, meanwhile, participates in the forward rush, and progresses with such strides, that it is only with difficulty that we can keep pace with it. Even the lightning speed of thought begins to flag in trying to follow some of the latest advances of astronomy. While some of us are pausing in the race to take breath, it may interest us to cast our eyes from the lofty heights to which we have attained, backward across the distant plains and tangled brakes, already growing dim in the gathering twilight. In the foreground, we can still discern the upward path, by which mankind has been travelling toward the point of vantage which we occupy, in their endeavor to reach the ever-receding goal of knowledge. The wild speculations and blunders of the old astronomers may raise a smile on the countenance of the amateur fin de siècle, who carties a telescope in his hand and a chronometer in his pocket; but it was the patient groping in the dark of the same men which enabled that smart individual to reach the standpoint which he now occupies: it was their indefatigable efforts and humble beginnings, which prepared a foundation for the mighty telescope recently erected in California, which conceived those divisions of the day and night by which Greenwich regulates our time, and which aroused the spirit of inquiry which led to the invention of that most marvellous of astronomical instruments, the spectroscope.

To the ancient Greek, Greece was alike the centre of the earth and the centre of the universe. Around him on every side lay the lands of barbarians, stretching away in hill and dale, mountain and valley, until, on the far distant horizon, they were bounded by the mighty ocean stream which girdled the whole earth with its ever circling course. To the west, his imagination pictured the isles of the blest, where Cronus peacefully ruled over the spirits of departed heroes, and the fertile soil bore thrice a year fruits as sweet as honey. Pindar, in his Olympian Odes, has beautifully described this happy land,

"Where o'er the isles of the blest the ocean breezes blow, and flowers gleam with gold, some on the earth, others on glistening trees, others the water feeds." The existence of these mythic realms of Cronus was doubtless suggested by the appearance of the western sky at sunset, when clouds low down on the horizon appear like islands on the verge of an illimitable and tranquil ocean.

On the further side of the deep-flowing ocean, beyond the setting sun, was a shore which was forever shrouded in mist and darkness-the land of the Cimmerians, the gate of the lower regions-to which Odysseus sailed in his black ship when he wished to hold converse with the spirits of the dead. The ancient Greek further conceived the sky as being a solid firmament of brass or crystal, upon whose under surface sun, moon, and stars appeared to glide. At the world's end, beyond the wide stream of ocean, this upper hemisphere of heaven joined the lower hemisphere of Tartarus, which similarly covered the under surface of the habitable earth. Within the lower hemisphere was included a gloomy region, where no ray of sunshine ever penetrated-the prison-house of the Titans who attempted to scale the heaven,

as far beneath the earth as heaven is above it," says the Hesiodic Theogony; "for nine days and nights would a brazen anvil be falling from heaven, and come cn the tenth to the earth; for nine days and nights again would it continue to fall, and come on the tenth to Tartarus. When Hephaestus, the smith-god, was kicked out of heaven into the volcanic isle of Lemnos, he too, it will be remembered, occupied nine days in falling to earth. "Around Tartarus, continues the Theogony, brazen fence has been forged, and about it threefold night is poured, while above it spring the roots of earth and barren

sea.

a

The entire universe, therefore, consisted of a mighty sphere or egg, in the midst of which the plane earth was fixed like a platform. At dawn the sun was believed to emerge from the ocean-river which was supported by that platform; at night it again descended into its waters and was extinguished. The inhabitants of the coast of Spain could hear the waters hissing as the great luminary plunged into his evening bath; and beyond the Suiones was a sluggish sea, presumably part of the

great ocean stream, where similar sounds could be heard at his rising. The light of the stars was in like manner extinguished when they dipped into the western waves. The poets figured the sun as a god, crowned with rays, who dashed at headlong speed across the sky, in a car drawn by four beautiful white horses, which breathed fire from their nostrils. But how did the sun, which set in the west, get back to the east at dawn? He did not descend beneath the earth and shine among the dead, though he once threatened to do so. Hephaestus, the divine smith, had fashioned for him a huge golden bowl, in which he slept at night, as he floated down the ocean current, until he arrived once more in the far east.

The attention of primitive man was early arrested by the striking appearance of the constellations of the heaven, groups of stars whose forms suggested the rude outlines of the wild beasts that he was accustomed to hunt in the forest. Fancy painted in these outlines on the canvas of the sky, adding many details, and inventing many fables to account for the periodical appearance of these mysterious phenomena of the night.

The most conspicuous and familiar of all the constellations was that known as "The Great Bear." Something seemed to distinguish it from the other important groups of stars in the northern sky, for night after night it appeared to move in a circle around the pole of the heaven; at one season high overhead, at another low down in the sky, but, unlike so many other constellations, it never dipped below the horizon or disappeared entirely from view. And so the Greek navigators used to steer by the Great Bear, because it indicated very roughly the position of the pole. The Phoenicians, who were better seamen and more fully acquainted with the movements of the stars, discovered, at a very early period, that the true pole of the heavens was more nearly indicated by the constellation of "The Little Bear" (which includes our "Pole-star"), and directed the course of their swift ships by observing the latter group. It is, perhaps, necessary to explain what the Greeks meant by the Pole. The earth, of course, had no poles in those days, for it was a plane surface (so at least men believed). Their word Tóλos meant a ball, and was applied originally to the whole vault of

heaven, and, later on, to that part of it which appeared most distant from the earth. Hence it came to mean the pivot on which the celestial hemisphere appears to revolve. The Pole-star is so near this imaginary pivot that it describes only a very small circle in the twenty-four hours, and, to all intents and purposes, it is the one fixed point of the sky. Science has taught us that this apparent revolution of the heaven is caused by the actual rotation of the earth upon its own axis, and that the pole, or absolutely motionless point of the sky, visible to the inhabitants of the northern hemisphere, must consequently be situated immediately over the Northpole of our earth, but so far as practical knowledge of the stars goes we have not improved very much upon the methods of the old Phoenician merchantmen. the clouds could hide from the pilot's eye these two Bears

Only

"Arctos oceani metuentes æquore tingi." The Homeric poems, composed some nine centuries before Christ, show that several of the constellations were, even then, known to the Grecks by the names which they still continue to bear. Ulysses, in the "Odyssey," "skilfully steers his bar, and sleep falls not upon his eyes as he keeps them fixed upon the Pleiades, latesetting Bootes, and the Bear (also called the Wagon), which turns itself in the same place, and watches Orion, and alone has no share in ocean baths." And, in the " Iliad," old Priam compares Achilles, whom he sees advancing to slay his son Hector, to a star which rises in summer, and whose resplendent rays shine among many stars in the dead of night. It men call the Dog of Orion. Very bright is that star, but it is a portent of ill, and brings excess of heat to miserable mortals.

Of the constellations mentioned in the above passages, Orion was pictured as a mighty hunter, of gigantic size and strength (the Nimrod of the Greeks). Accompanied by his dog Sitius, "the scorcher, most brilliant of all stars, he advances to give the Great Bear the coup de grâce, while that huge animal seems slowly to turn at bay near the pole. The Pleiads were daughters of Atlas, chased by Orion. Their name has been derived from hεiv, to sail, because so long as they appeared in the sky, navigation was

considered safe. There was a curious tradition among the ancients, that there were once seven stars in this group. Only six are now visible to the naked eye. Qua septem dici sex tamen esse solebant," says Ovid. The legend founded upon this alleged disappearance of one of the component lights was that a daughter of Atlas married a mortal, and so her light was dimmed. Another cluster which is mentioned in the Homeric poems, the Hyades, or rainy stars, foretold wet weather. Later poets represent the Pleiads as a flock of pigeons, zeλelades, and the Hyades, by a similar play upon the name, as a herd of piglings, vades, chased by the celestial hunter. Agricultural man saw in the constellation of the Great Bear the representation of a wagon or plough, and Boötes was the man in charge of its team of oxen.

One of the Hesiodic poems, 66 The Works and Days," composed, perhaps, a century and a half later than the Homeric, gives precept upon precept to faimer and mariner, and teaches them how to observe the seasons, at a period when almanacs are as yet unknown.

"When the Pleiads, daughters of Atlas, rise, begin your harvest; when they set, your ploughing. When, after the winter solstice, Zeus has fulfilled sixty days of winter, then it is that Arcturus, having left the sacred stream of Ocean, rises in the twilight brightly beaming, prune your vines. When Sirius parches head and knees, and the body is dried up by reason of heat, then sit in the shade and drink. When Orion and Sirius have reached mid-heaven, and rosy-fingered dawn beholds Arcturus, then gather and carry home your grape clusters. When, flying the impetuous might of Orion, the Pleiads sink into the misty deep, then rage blasts of wind, haul ashore your ship and cover her around with stones."

The mention of the solstice here and elsewhere in the poem implies careful astronomical observation. Arcturus, "the bear-keeper, " is a bright star in the constellation Boötes.

The Greek year cousisted of three seasons only. Prometheus enumerates them. "They had no sign," says he, "of winter, of flowery spring, or fruitful summer." In ancient Germany a similar division of the year prevailed, for Tacitus makes the caustic remark that, among the

Germans, winter, spring, and summer have a meaning and a name, but to that people the name and blessings of autumn are alike unknown.

It is not likely, then, that our Saxon forefathers were acquainted with the lastnamed season, and our very term autumn is an echo of the Roman tongue. It was the moon, and not the sun, which first suggested to mankind the circle of the year as a measure of time. The sun exhibits no changes of appearance, and his light obliterates all the landmarks of the sky. A luminary which is the same yesterday, to-day, and to-morrow, might give rise to conceptions of perfection and eternity, but, beyond the alternations of day and night, it could suggest to men's minds no abstract measure of time. But with our humble satellite it is far otherwise. The regularly recurring phenomena of new moon and full moon are too marked to escape the attention of the most obtuse and unreflecting of savages. The motion of the sun may be compared to that of the minute-band of a clock, sweeping on bour after hour without leaving much record of its comparatively vast journey; the progress of the moon, on the contrary, may be likened to that of the hour-hand, which registers the movements of its companion, and resolves them into twelve well-defined periods.

The interval between two new moons is called a lunation or synodic month, and twelve of such lunations were found to coincide very roughly with the period in which the sun returned to the goal in the sky from which he had started, and to correspond with the return of that most marked of natural phenomena, the budding of trees in spring.

But after making this important discovery the calendar-makers plunged into a slough of difficulties, from which they were long in emerging. They made the natural mistake of supposing that the year was a standard period of time, given by divine appointment to man, and that the sun and moon conspired in their operations, so as to form in effect the hands of a great natural and infallible clock, contrived and regulated by the gods themselves, for the purpose of preserving unimpaired the cycle of their own religious festivals.

But such, alas! is not the case. The tropical year, which is the period in which

the sun appears to make a complete circuit of the heaven, or, to state the same thing in scientific language, the period within which the earth actually makes one complete revolution in its orbit round the sun, consists of 365 days. I am disregarding the fraction.

Now the lunation (or interval between new moon and new moon, or full moon and full moon) consists of 29 days, so that twelve lunations make up a cycle of only 354 days. And so it came to pass that people who reckoned by the moon had finished their year 11 days before the sun had accomplished his full course, and the ever-accumulating difference between. the solar year and twelve lunations gradually shifted the first day of the civil year backward, step by step, until, if left to itself, it had made the tour of the seasons. And so all was confusion, the Athenians beginning their year at the summer solstice, the Spartans at the autumnal equinox. The ingenuity of man was therefore exercised in solving the problem of how, by the insertion or addition of intercalary or supernumerary days, to keep lunar time abreast of solar time. The want of perfect scientific instruments prevented the ancients from exactly hitting off to a nicety the respective lengths of the solar and lunar year, and what addition must consequently be made to the latter in order to reconcile it with the former. And so the cooking of the calendar was spoiled, as much by the uncertainty as by the number of the cooks employed in the process. They sometimes added too much, sometimes too little, of the necessary ingredi

ent.

The old Greeks, who reckoned by the moon, made use of a year of 360 days. Their calculation was founded upon the double error that a lunation consists of exactly 30 days (whereas it contains only 29 days, 12 hours and 44 minutes), and that twelve lunations amounting to 360 days coincide with the solar year.

Hence we learn from Herodotus that the Cilicians paid a tribute of 360 white horses, being one horse for every day in the year. One of the things which most struck the same historian, during his visit to Egypt, was the native method of regulating the calendar. Their superior knowledge of astronomy had taught the people of that country to divide the civil year into 365 days, and so make it very nearly

correspond with the natural circuit of the seasons, whereas the more cumbrous Greek method was to add biennially to their standard year of 360 days an intercalary month," equivalent to the difference between solar and civil time.

That the solar year consisted of 365 complete days was a matter of common knowledge from a comparatively early period, but there is an insidious fraction involved in the calculation, which puzzled the early astronomers and has been the cause of endless trouble to the makers of calendars.

There was a tradition among the Romans that their mythical king, Romulus, had invented a year of ten months only, and that his successor, Numa, had added two more to make up twelve.

The origin of this story appears to be that a sequence of months bore numerical names Quintilis (July), Sextilis (August), September, October, November, December, while the two last, January and February, were not numbered. Julius Cæsar reformed the Roman Calendar in the year 46 B. C. He shifted the commencement of the year back to January 1, and, acting upon the advice of an expert from the school of astronomy at Alexandria, he fixed the length of the civil year at 365 days. The fraction of 6 hours amounted at the expiration of four years. to one complete day of 24 hours, and so he ordered that every fourth year the sixth day before the calends of March should be reckoned twice. Hence the origin of the name Bissextile for leap year. It might be supposed that Cæsar's astronomical reckoning, if not absolutely perfect, was yet sufficiently so for all the practical purposes of daily life. But no His year of 365 days was longer than the natural solar year by 11 minutes and 14 seconds, and the result was that, in the year of grace 1582, the civil time had become so fast, that while the equinox, according to the calendar, fell on March 11, the equinox de facto did not fall until 10 days later, on the 21st of the same month. Pope Gregory XIII. therefore cut ten days off the year 1582, by reckoning October 5 in that year as the 15th day of the month. But there still remained a risk of future error, for the discrepancy between the Julian and Gregorian calendars would continue to accumulate as of old. It was ascertained that this discrep

ancy of 11 minutes and 14 seconds would amount, in the course of four centuries, to three complete days, and, in order to eliminate those superfluous days, it was directed by the Pope that three out of every four years commencing a new century should not be leap year. Thus the year 1600 was leap year, but 1700 and 1800 were not, 1900 will not be, but the year 2000 will contain the extra day. Thus equilibrium is preserved, and the calendar is rendered for the future as nearly fre from error as it is possible for the wit of man to make it. The Gregorian calendar, or new style, was not adopted by the English until the year 1752, when the discrepancy between it and the Julian calendar, or old style, had grown to eleven days; so we cut off that period from the year 1752, by reckoning September 3 as the 14th. The difference between the two calendars now amounts to twelve days, as will be seen on reference to the almanacs of Eastern Europe, where the old style still prevails.

My object, in thus digressing somewhat from my subject, has been to show that we are indebted to the old Greek astronomers of Alexandria for the compilation of the calendar which we are using at this moment. Its final correction in the sixteenth century was only one of small detail, and even that was accomplished before the invention of the telescope.

Thales of Miletus, one of the seven sages, was the first astronomer of any note among the Greeks. He lived about 640 B.C., and founded the Ionic school of philosophy. He traced the ecliptic, or pathway of the sun through the sky, and was cognizant of its oblique position with regard to the equator. He wrote a description of the equinox and solstice, but, as his writings are lost, we only know his doctrines from the accounts given by

others.

The earth, according to his theory, was a flat plane, and floated upon a vast body of water. He knew that the moon's light was a reflection from the sun, that an eclipse of the moon was due to the interposition of the earth between that planet and the sun, and an eclipse of the sun to the intervention of the moon between the earth and the sun. He introduced to the Greek mariners the Little Bear of the Phoenicians, as a mark by which to steer their ships. An eclipse of the sun, which NEW SERIES.-VOL, LVII., No. 1

brought a battle to an abrupt termination, is said to have been predicted by him, perhaps after the event. But this learned recluse, and originator of the proverb "Know thyself, was not infallible, for it is related that one night, when he was led forth by an old daine to look at the stars, as was his wont, he fell into a ditch, and when he began to bewail his unlucky fate, his conductress exclaimed, "Do you think, Thales, that you can possibly understand what is in the sky, when you can't even see what is down at your feet?"

เ

Anaximander, a pupil of Thales, so far departed from the doctrines of his master as to conceive the earth as a cylindrical body, suspended in the exact centre of the universe. For," said he, since the earth is equidistant from the vault of heaven in every direction, there is no particular reason why it should move in one direction more than in another. То "the plain man," who prided himself on his common sense, this argument must have appeared unanswerable. Anaximander introduced the sun dial into Greece. It consisted of an upright rod (yvwμwv) set in the centre of a hollow hemisphere (mólos), on the inner surface of which were marked twelve divisions, representing twelve hours of daylight. Herodotus attributes its invention to the Babylonians. The Greeks had been long acquainted with the gnomon, or pillar, which cast a shade on the ground, and showed by its shortest shadow the moment of noon when the sun had reached the meridian, while a comparison of all the meridiau shadows during the year would indicate the time of the solstices. Aristophanes tells us that guests were invited when the shadow of the gnomon was of such and such a length. The sun-dial proper was probably coming into use at Rome about 220 B. C., for Plautus makes his hungry parasite say, "May the gods confound the man who first invented hours and put this sun-dial here, to cut my day to pieces. When I was a boy, my stomach was my sun-dial," etc.

In the fifth century before Christ, Anaximenes taught that the stars were fixed like nails in the solid hemisphere of hearen, and with it they circled around the earth, but could not pass underneath it, because, no doubt, he believed like his contemporary Xenophanes, that the foundations of the earth lie at an unfathomable depth beneath our feet. The sun, too, as

4