Astronomical Myths Part 7

Now we come to the question, what is the meaning of the particular angles at which the north-looking and south-looking pa.s.sages rise, if, as we now believe, they must have _some_ meaning.

The exits of these pa.s.sages were closed, and they could not therefore have been for observation, but they may have been so arranged as to be a memorial of any remarkable phenomena to be seen in those directions. To ascertain if there be any such to which they point, we must throw back the heavens to their position in the days of the Egyptians, because, as we have seen, the precession of the equinoxes alters the meridian alt.i.tude of every star. As the pa.s.sages point north and south, if they refer to any star at all, it must be to their pa.s.sing the meridian.

Now let us take the heavens as they were 2170 B.C., the date at which the Pleiades _really_ commenced the spring, by their midnight culmination, and ask how high they would be then. The answer of astronomy is remarkable--"_Exactly at that height that they could be seen in the direction of the southward-pointing pa.s.sage of the pyramid._" And would any star then be in a position to be seen in the direction of the other or northward-looking pa.s.sage? Yes, the largest star in the constellation of the Dragon, which would be so near the pole (3 52') as to be taken as the Pole Star in those days. These are such remarkable coincidences in a structure admittedly made with mathematical accuracy and design, and truly executed, that we cannot take them to be accidental, but must endeavour to account for them.

The simplest explanation seems to be, that everything in the pyramid is intended to represent some standard or measure, and that these pa.s.sages have to do with their year. They had received the year of the Pleiades from a remoter antiquity than their own, they had discovered the true commencement of solar spring, as determined from the solar autumnal equinox, and they commemorated by the building of the pyramid the coincidence of the two dates, making pa.s.sages in it which would have no meaning except at that particular time.

Whether the pyramid was built _at that time_, or whether their astronomical knowledge was sufficient to enable them to predict it and build accordingly, just as we calculate back to it, we have no means of knowing. It is very possible that the pyramid may have been built by some immigrating race more learned in astronomy, like the Accadians among the Babylonians.

Either the whole of the conclusions respecting the pyramid is founded on pure imagination and the whole work upon it thrown away, or we have here another very remarkable proof of the influence of the Pleiades on the reckoning of the year, and a very interesting chapter in the history of the heavens.

Following the guidance of Mr. Haliburton, we shall find still more customs, and names depending in all probability on the influence the Pleiades once exerted, and the observances connected with the feasts in their honour.

The name by which the Pleiades are known among the Polynesians is the "Tau," which means a season, and they speak of the years of the Tau, that is of the Pleiades. Now we have seen that the Egyptians had similar feasts at similar times, in relation to this constellation, and argued that they did not arise independently. This seems still further proved by their name for these stars--the Atauria.

Now the Egyptians do not appear to have derived their signs of the Zodiac from the same source; these had a Babylonian origin, and the constellation in which the Pleiades were placed by the latter people was the Bull, by whatever name he went. The Egyptians, we may make the fair surmise, adopted from both sources; they took the Pleiades to indicate the Bull, and they called this animal after the Atauria. From thence we got the Latin Taurus, and the German Thier.

It is possible that this somehow got connected with the letter "tau" in Greek, which seems itself connected with the sacred scarabaeus or Tau-beetle of Egypt; but the nature of the connection is by no means obvious. Mr. Haliburton even suggests that the "tors" and "Arthur's seat," which are names given to British hill-tops, may be connected with the "high places," of the wors.h.i.+p of the Pleiades, but of this we have no proof.

Among the customs possibly derived from the ancients, through the Phoenicians, though now adopted as conveying a different meaning in a Christian sense, is that of the "hot cross bun," or "bull cake." It is found on Egyptian monuments, signifying the four quarters of the year, and sometimes stamped with the head and horns of the bull. It is found among ourselves too, essentially connected with the dead, and something similar to it appears in the "soul cake" connected originally with All Souls' Day.

Among the Scotch it was traditionally thought that on New Year's Eve the Candlemas Bull can be seen, rising at twilight and sailing over the heavens--a very near approach to a matter-of-fact statement.

We have seen that among the ancient Indians there was some notice taken of the Pleiades, and that they in all probability guided their year by them or by some other stars: it would therefore behove them to know something of the precession of the equinoxes. It seems very well proved that their days of Brahma and other periods were meant to represent some astronomical cycles, and among these we find one that is applicable to the above. They said that in every thousand divine ages, or in every day of Brahma, fourteen Menus are successively invested with the sovereignty of the earth. Each Menu transmits his empire to his sons during seventy-one divine ages. We may find a meaning for this by putting it that the equinox goes forward fourteen days in each thousand years, and each day takes up seventy-one years.

These may not be the only ones among the various customs, sayings, and names that are due in one way or other to this primitive method of arranging the seasons by the positions of the stars, especially of those most remarkable and conspicuous ones the Pleiades, but they are those that are best authenticated. If the connection between the Pleiades and the festival of the dead, the new year and a deluge, can be clearly made out; if the tradition of the latter be found as universal as that of the former, and be connected with it in the Mosaic narrative; if we can trace all these traditions to the south of the equator, and find numerous further traditions connected with islands, we may find some reason for believing in their theory who suggest that the early progenitors of the human race (? all of them) were inhabitants of some fortunate islands of even temperature in the southern hemisphere, where they made some progress in civilisation, but that their island was swallowed up by the sea, and that they only escaped by making huge vessels, and, being carried by the waves, they landed on continental sh.o.r.es, where they commemorated yearly the great catastrophe that had happened to them, notifying its time by the position of the Pleiades, making it a feast of the dead whom they had left behind, and opening the year with the day, whether it were spring or not, and handing down to their descendants and to those among whom they came, the traditions and customs which such events had impressed upon them.

Whether such an account be probable, mythical, or unnatural, there are certainly some strange things to account for in connection with the Pleiades.

CHAPTER VI.

THE NATURE AND STRUCTURE OF THE HEAVENS ACCORDING TO THE ANCIENTS.

Many and various have been the ideas entertained by reflecting men in former times on the nature and construction of the heavenly vault, wherein appeared those stars and constellations whose history we have already traced. Is it solid? or liquid? or gaseous? Each of these and many other suppositions have been duly formulated by the ancient philosophers and sages, although, as we are told by modern astronomy, it does not exist at all.

In our study of the ancient ideas about the structure of the universe, we will commence with that early and curious system which considered the heavenly vault to be material and solid.

The theory of a solid sky received the a.s.sent of all the most ancient philosophers. In his commentary on Aristotle's work on the heavens, Simplicius reveals the repugnance the ancient philosophers felt in admitting that a star could stand alone in s.p.a.ce, or have a free motion of its own. It must have a support, and they therefore conceived that the sky must be solid. However strange this idea may now appear, it formed for many centuries the basis of all astronomical theories. Thus Anaximenas (in the sixth century B.C.) is related by Plutarch to have said that "the outer sky is solid and crystalline," and that the stars are "fixed to its surface like studs," but he does not say on what this opinion was founded, though it is probable that, like his master Anaximander, he could not understand how the stars could move without being supported.

Pythagoras, who lived about the same epoch, is also supposed by some to have held the same views, and it is possible that they all borrowed these ideas from the Persians, whose earliest astronomers are said in the _Zend avesta_ to have believed in concentric solid skies.

Eudoxus of Cnidus, in the fifth century B.C., is said by his commentator Aratus to have also believed in the solidity of the heavens, but his reasons are not a.s.signed.

Notwithstanding these previously expressed opinions, Aristotle (fourth century, B.C.) has for a long time been generally supposed to be the inventor of solid skies, but in fact he only gave the idea his valuable and entire support. The sphere of the stars was his eighth heaven. The less elevated heavens, in which he also believed, were invented to explain as well as they might, the proper motions of the sun, moon, and planets.

The philosopher of Stagira said that the motion of his eighth or outermost solid sky was uniform, nor ever troubled by any perturbation.

"Within the universe there is," he says, "a fixed and immovable centre, the earth; and without there is a bounding surface enclosing it on all sides. The outermost part of the universe is the sky. It is filled with heavenly bodies which we know as stars, and it has a perpetual motion, carrying round with it these immortal bodies in its unaltering and unending revolution."

Euclid, to whom we may a.s.sign a date of about 275 before our present era, also considered the stars to be set in a solid sphere, having the eye of the observer as centre; though for him this conception was simply a deduction from exact and fundamental observations, namely, that their revolution took place as a whole, the shape and size of the constellation being never altered.

Cicero, in the last century before Christ, declared himself a believer in the solidity of the sky. According to him the ether was too rarefied to enable it to move the stars, which must therefore require to be fixed to a sphere of their own, independent of the ether.

In the time of Seneca there seem to have been difficulties already raised about the solidity of the heavens, for he only mentions it in the form of a question--"Is the sky solid and of a firm and compact substance?" (_Questions_, Book ii.)

In the fifth century the idea of the star sphere still lingered, and in the eyes of Simplicius, the commentator of Aristotle, it was not merely an artifice suitable for the representation of the apparent motions, but a firm and solid reality; while Mahomet and most of the Fathers of the Christian Church had the same conception of these concentric spheres.

It appears then from this review that the phrases "starry vault," and especially "fixed stars," have been used in two very distinct senses.

When we meet with them in Aristotle or Ptolemy, it is obvious that they have reference to the crystal sphere of Anaximenas, to which they were supposed to be affixed, and to move with it; but that later the word "fixed" carried with it the sense of immovable, and the stars were conceived as fixed in this sense, independently of the sphere to which they were originally thought to be attached. Thus Seneca speaks of them as the _fixum et immobilem populum_.

If we would inquire a little further into the supposed nature of this solid sphere, we find that Empedocles considered it to be a solid ma.s.s, formed of a portion of the ether which the elementary fire has converted into crystal, and his ideas of the connection between cold and solidification being not very precise, he described it by names that give the best idea of transparence, and, like Lactantius, called it _vitreum caelum_, or said _caelum aerem glaciatum esse_, though we cannot suppose that he made any allusion to what we now call gla.s.s, but simply meant some body eminently transparent into which the fire had transformed the air; while so far from having any idea of cold, as we might imagine possible from observations of the snowy tops of mountains, they actually believed in a warm region above the lower atmosphere. Thus Aristotle considers that the spheres heat by their motion the air below them, without being heated themselves, and that there is thus a production of heat. "The motion of the sphere of fixed stars," he says, "is the most rapid, as it moves in a circle with all the bodies attached to it, and the s.p.a.ces immediately below are strongly heated by the motion, and the heat, thus engendered, is propagated downwards to the earth." This however, strangely enough, does not appear to have prevented their supposing an eternal cold to reign in the regions next below, for Macrobius, in his commentary on Cicero, speaks of the decrease of temperature with the height, and concludes that the extreme zones of the heavens where Saturn moves must be eternally cold; but this they reckoned as part of the atmosphere, beyond whose limits alone was to be found the fiery ether.

It is to the Fathers of the Church that we owe the transmission during the middle ages of the idea of a crystal vault. They conceived a heaven of gla.s.s composed of eight or ten superposed layers, something like so many skins in an onion. This idea seems to have lingered on in certain cloisters of southern Europe even into the nineteenth century, for a venerable Prince of the Church told Humboldt in 1815, that a large aerolite lately fallen, which was covered with a vitrified crust, must be a fragment of the crystalline sky. On these various spheres, one enveloping without touching another, they supposed the several planets to be fixed, as we shall see in a subsequent chapter.

Whether the greater minds of antiquity, such as Plato, Plutarch, Eudoxus, Aristotle, Apollonius, believed in the reality of these concentric spheres to carry the planets, or whether this conception was not rather with them an imaginary one, serving only to simplify calculation and a.s.sist the mind in the solution of the difficult problem of their motion, is a point on which even Humboldt cannot decide. It is certain, however, that in the middle of the sixteenth century, when the theory involved no less than seventy-seven concentric spheres, and later, when the adversaries of Copernicus brought them all into prominence to defend the system of Ptolemy, the belief in the existence of these solid spheres, circles and epicycles, which was under the especial patronage of the Church, was very widespread.

Tycho Brahe expressly boasts of having been the first, by considerations concerning the orbits of the comets, to have demonstrated the impossibility of solid spheres, and to have upset this ingenious scaffolding. He supposed the s.p.a.ces of our system to be filled with air, and that this medium, disturbed by the motion of the heavenly bodies, opposed a resistance which gave rise to the harmonic sounds.

It should be added also that the Grecian philosophers, though little fond of observation, but rejoicing rather in framing systems for the explanation of phenomena of which they possessed but the faintest glimpse, have left us some ideas about the nature of shooting stars and aerolites that come very close to those that are now accepted. "Some philosophers think," says Plutarch in his life of Lysander, "that shooting stars are not detached particles of ether which are extinguished by the atmosphere soon after being ignited, nor do they arise from the combustion of the rarefied air in the upper regions, but that they are rather heavenly bodies which fall, that is to say, which escaping in some way from the general force of rotation are precipitated in an irregular manner, sometimes on inhabited portions of the earth, but sometimes also in the ocean, where of course they cannot be found."

Diogenes of Apollonius expresses himself still more clearly: "Amongst the stars that are visible move others that are invisible, to which in consequence we are unable to give any name. These latter often fall to the earth and take fire like that star-stone which fell all on fire near aegos Potamos." These ideas were no doubt borrowed from some more ancient source, as he believed that all the stars were made of something like pumice-stone. Anaxagoras, in fact, thought that all the heavenly bodies were fragments of rocks which the ether, by the force of its circular motion, had detached from the earth, set fire to, and turned into stars. Thus the Ionic school, with Diogenes of Apollonius, placed the aerolites and the stars in one cla.s.s, and a.s.signed to all of them a terrestrial origin, though in this sense only, that the earth, being the central body, had furnished the matter for all those that surround it.

Plutarch speaks thus of this curious combination:--"Anaxagoras teaches that the ambient ether is of an igneous nature, and by the force of its gyratory motion it tears off blocks of stone, renders them incandescent, and transforms them into stars." It appears that he explained also by an a.n.a.logous effect of the circular motion the descent of the Nemaean Lion, which, according to an old tradition, fell out of the moon upon the Peloponnesus. According to Boeckh, this ancient myth of the Nemaean Lion had an astronomical origin, and was symbolically connected in chronology with the cycle of intercalation of the lunar year, with the wors.h.i.+p of the moon in Nemaea, and the games by which it was accompanied.

[Ill.u.s.tration: PLATE VI.--THE NEMaeAN LION.]

Anaxagoras explains the apparent motion of the celestial sphere from east to west by the hypothesis of a general revolution, the interruption of which, as we have just seen, caused the fall of meteoric stones. This hypothesis is the point of departure of the theory of vortices, which more than two thousand years later, by the labours of Descartes, Huyghens, and Hooke, took so prominent a place among the theories of the world.

It may be worth adding with regard to the famous aerolite of aegos Potamus, alluded to above, that when the heavens were no longer believed to be solid, the faith in the celestial origin of this, as of other aerolites, was for a long time destroyed. Thus Bailly the astronomer, alluding to it, says, "if the fact be true, this stone must have been thrown out by a volcano." Indeed it is only within the last century that it has been finally accepted for fact that stones do fall from the sky.

Laplace thought it probable that they came from the moon; but it has now been demonstrated that aerolites, meteors, and shooting stars belong all to one cla.s.s of heavenly bodies, that they are fragments scattered through s.p.a.ce, and circulate like the planets round the sun. When the earth in its motion crosses this heavenly host, those which come near enough to touch its atmosphere leave a luminous train behind them by their heating by friction with the air: these are the _shooting stars_.

Sometimes they come so close as to appear larger than the moon, then they are _meteors;_ and sometimes too the attraction of the earth makes them fall to it, and these become _aerolites_.

But to return to our ancient astronomers:--

They believed the heavens to be in motion, not only because they saw the motion with their eyes, but because they believed them to be animated, and regarded motion as the essence of life. They judged of the rapidity of the stars' motion by a very ingenious means. They perceived that it was greater than that of a horse, a bird, an arrow, or even of the voice, and Cleomenas endeavoured to estimate it in the following way. He remarks that when the king of Persia made war upon Greece he placed men at certain intervals, so as to lie in hearing of each other, and thus pa.s.sed on the news from Athens to Susa. Now this news took two days and nights to pa.s.s over this distance. The voice therefore only accomplished a fraction of the distance that the stars had accomplished twice in the same time.

The heavens, as we have seen, were not supposed to consist of a single sphere, but of several concentric ones, the arrangement and names of which we must now inquire into.

The early Chaldeans established three. The first was the empyreal heaven, which was the most remote. This, which they called also the solid firmament, was made of fire, but of fire of so rare and penetrating a nature, that it easily pa.s.sed through the other heavens, and became universally diffused, and in this way reached the earth. The second was the ethereal heaven, containing the stars, which were simply formed of the more compact and denser parts of this substance; and the third heaven was that of the planets. The Persians, however, gave a separate heaven to the sun, and another to the moon.

The system which has enjoyed the longest and most widely-spread reign is that which places above, or rather round, the solid firmament a heaven of water--(the nature of which is not accurately defined), and round this a _primum mobile_, prime mover, or originator of all the motions, and round all this the empyreal heaven, or abode of the blessed. In the most anciently printed scientific encyclopaedia known, the _Magarita philosophica_, edited in the fifteenth century, that is, two centuries before the adoption of the true system of the world, we have the curious figure represented on the next page, in which we find no less than eleven different heavens. We here see on the exterior the solid empyreal heaven, which is stated in the body of the work to be the abode of the blessed and to be immovable, while the next heaven gives motion to all within, and is followed by the aqueous heaven, then the crystal firmament, and lastly by the several heavens of the planets, sun, and moon. The revolution of these spheres was not supposed to take place, like the motion of the earth in modern astronomy, round an imaginary axis, but round one which had a material existence, which was provided with pivots moving in fixed sockets. Thus Vitruvius, architect to Augustus, teaches it expressly in these words:--

"The heaven turns continually round the earth and sea upon an axis, where two extremities are like two pivots that sustain it: for there are two places in which the Governor of Nature has fas.h.i.+oned and set these pivots as two centres; one is above the earth among the northern stars; the other is at the opposite end beneath the earth to the south; and around these pivots, as round two centres, he has placed little naves, like those of a wheel upon which the heaven turns continually."

[Ill.u.s.tration: FIG. 13.]

Similarly curious ideas we shall find to have prevailed with respect to the meaning of everything that they observed in the heavens: thus what a number of opinions have been hazarded on the nature of the "Milky Way"