Astronomical Myths Part 12

Nevertheless, as presenting us with the first recorded ideas on these questions of the nature and properties of the earth, it deserves attentive study. It is not a system of observations like those of Ptolemy and the Alexandrian School, but an entirely theoretical work. It is founded entirely on logic; but unfortunately, if the premisses are bad, the better the syllogism the more erroneous will be the conclusion; and it is just this which we find here. Thus if he be asked whether the earth turns or the heavens, he will reply that the earth is _evidently_ in repose, and that this is the case not only because we observe it to be so, but because it is a necessity that it should be; because repose is _natural_ to the earth, and it is _naturally_ in equilibrium. This idea of "natural" leads very often astray. He is guided to his idea of what is natural by seeing what is, and then argues that what is, or appears to be, must be, because it is natural--thus arguing in a circle.

Another example may be given in his answer to the question, Why must the stars move round the earth? He says it is natural, because a circle is a more perfect line, and must therefore be described by the perfect stars, and a circle is perfect because it has no ends! Unfortunately there are other curves that have no ends; but the circle was considered, without more reason, the most perfect curve, and therefore the planets must move in circles--an idea which had to wait till Kepler's time to be exploded. One more specimen of this style may be quoted, namely, his proof that every part of heaven must be eternally moving, while the earth must be in the centre and at rest. The proof is this. Everything which performs any act has been made for the purpose of that act. Now the work of G.o.d is immortality, from which it follows that all that is divine must have an eternal motion. But the heavens have a divine quality, and for this reason they have a spherical shape and move eternally in a circle. Now when a body has a circular motion, one part of it must remain at rest in its place, namely, that which is in the centre; the earth is in the centre--therefore it is at rest.

Aristotle says in this work that there are two kinds of simple motion, that in a circle and that in a straight line. The latter belongs to the elements, which either go up or down, and the former to the celestial bodies, whose nature is more divine, and which have never been known to change; and the earth and world must be the only bodies in existence, for if there were another, it must be the contrary to this, and there is no contrary to a circle; and again, if there were any other body, the earth would be attracted towards it, and move, which it does not. Such is the style of argument which was in those days thought conclusive, and which with a little development and inflation of language appeared intensely profound.

But what brings these speculations to the subject we have now in hand is this: that when Aristotle thus proves the earth to be immovable in the centre of the universe, he is led on to inquire how it is possible for it to remain in one fixed place. He observed that even a small fragment of earth, when it is raised into the air and then let go, immediately falls without ever stopping in one place--falling, as he supposed, all the quicker according to its weight; and he was therefore puzzled to know why the whole ma.s.s of the earth, notwithstanding its weight, could be kept from falling.

Aristotle examines one by one the answers that have been given to this question. Thus Xenophanes gave to the earth infinitely extended roots, against which Empedocles uses such arguments as we should use now.

Thales of Miletus makes the earth rest upon water, without finding anything on which the water itself can rest, or answering the question how it is that the heavier earth can be supported on the lighter water.

Anaxemenes, Anaxagoras, and Democritus, who make the earth flat, consider it to be sustained by the air, which is acc.u.mulated below it, and also presses down upon it like a great coverlet. Aristotle himself says that he agrees with those philosophers who think that the earth is brought to the centre by the primitive rotation of things, and that we may compare it, as Empedocles does, to the water in gla.s.ses which are made to turn rapidly, and which does not fall out or move, even though upside down. He also quotes with approval another opinion somewhat similar to this, namely, that of Anaximander, which states that the earth is in repose, on account of its own equilibrium. Placed in the centre and at an equal distance from its extremities, there is no reason why it should move in one direction rather than the other, and rests immovable in the centre without being able to leave it.

The result of all is that Aristotle concludes that the earth is immovable, in the centre of the universe, and that it is not a star circulating in s.p.a.ce like other stars, and that it does not rotate upon its axis; and he completes the system by stating that the earth is spherical, which is proved by the different aspects of the heavens to a voyager to the north or to the south.

Such was the Aristotelian system, containing far more error than truth, which was the first of any completeness. Scattered ideas, however, on the shape and method of support of the earth and the cause of various phenomena, such as the circulation of the stars, are met with besides in abundance.

The original ideas of the earth were naturally tinged by the prepossessions of each race, every one thinking his own country to be situated in the centre. Thus among the Hindoos, who lived near the equator, and among the Scandinavians, inhabiting regions nearer the pole, the same meaning attaches to the words by which they express their own country, _medpiama_ and _medgard_, both meaning the central habitation. Olympus among the Greeks was made the centre of the earth, and afterwards the temple of Delphi. For the Egyptians the central point was Thebes; for the a.s.syrians it was Babylon; for the Indians it was the mountain Mero; for the Hebrews Jerusalem. The Chinese always called their country the central empire. It was then the custom to denote the world by a large disc, surrounded on all sides by a marvellous and inaccessible ocean. At the extremities of the earth were placed imaginary regions and fortunate isles, inhabited by giants or pigmies.

The vault of the sky was supposed to be supported by enormous mountains and mysterious columns.

Numerous variations have been suggested on the earliest supposed form of the earth, which was, as we have seen in a former chapter, originally supposed to be an immense flat of infinite depth, and giving support to the heavens.

As travels extended and geography began to be a science, it was remarked that an immense area of water circ.u.mscribed the solid earth by irregular boundaries--whence the idea of a universal ocean.

When, however, it was perceived that the horizon at sea was always circular, it was supposed that the ocean was bounded, and the whole earth came to be represented as contained in a circle, beneath which were roots reaching downwards without end, but with no imagined support.

[Ill.u.s.tration: FIG. 25.--THE EARTH FLOATING.]

[Ill.u.s.tration: FIG. 26.--THE EARTH WITH ROOTS.]

The Vedic priests a.s.serted that the earth was supported on twelve columns, which they very ingeniously turned to their own account by a.s.serting that these columns were supported by virtue of the sacrifices that were made to the G.o.ds, so that if these were not made the earth would collapse.

[Ill.u.s.tration: FIG. 27.--THE EARTH OF THE VEDIC PRIESTS.]

These pillars were invented in order to account for the pa.s.sing of the sun beneath the earth after his setting, for which at first they were obliged to imagine a system of tunnels, which gradually became enlarged to the intervals between the pillars.

The Hindoos made the hemispherical earth to be supported upon four elephants, and the four elephants to stand on the back of an immense tortoise, which itself floated on the surface of a universal ocean. We are not however to laugh at this as intended to be literal; the elephants symbolised, it may be, the four elements, or the four directions of the compa.s.s, and the tortoise was the symbol for strength and for eternity, which was also sometimes represented by a serpent.

[Ill.u.s.tration: FIG. 28.--HINDOO EARTH.]

The floating of the earth on water or some other liquid long held ground. It was adopted by Thales, and six centuries later Seneca adopts the same opinion, saying that the humid element that supports the earth's disc like a vessel may be either the ocean or some liquid more simple than water.

Diodorus tells us that the Chaldeans considered the earth hollow and boat-shaped--perhaps turned upside down--and this doctrine was introduced into Greece by Herac.l.i.tus of Ephesus.

[Ill.u.s.tration: FIG. 29.--THE EARTH OF ANAXIMANDER.]

Anaximander represents the earth as a cylinder, the upper face of which alone is inhabited. This cylinder, he states, is one-third as high as its diameter, and it floats freely in the centre of the celestial vault, because there is no reason why it should move to one side rather than the other. Leucippus, Democritus, Herac.l.i.tus, and Anaxagoras all adopted this purely imaginary form. Europe made the northern half, and Lybia (Africa) and Asia the southern, while Delphi was in the centre.

Anaximenes, without giving a precise opinion as to the form of the earth, made it out to be supported on compressed air, though he gave no idea as to how the air was to be compressed.

Plato thought to improve upon these ideas by making the earth cubical.

The cube, which is bound by six equal faces, appeared to him the most perfect of solids, and therefore most suitable for the earth, which was to stand in the centre of the universe.

[Ill.u.s.tration: FIG. 30.--PLATO'S CUBICAL EARTH.]

Eudoxus, who in his long voyages throughout Greece and Egypt had seen new constellations appear as he went south, while others to the north disappeared, deduced the sphericity of the earth, in which opinion he was followed by Archimedes, and, as we have seen, by Aristotle.

According to Achilles Tatius, Xenophanes gave to the earth the shape of an immense inclined plane, which stretched out to infinity. He drew it in the form of a vast mountain. The summit only was inhabited by men, and round it circulated the stars, and the base was at an infinite depth. Hesiod had before this obscurely said: "The abyss is surrounded by a brazen barrier; above it rest the roots of the earth." Epicurus and his school were well pleased with this representation. If such were the foundations of the earth, then it was impossible that the sun, and moon, and stars should complete their revolutions beneath it. A solid and indefinite support being once admitted, the Epicurean ideas about the stars were a necessary consequence; the stars must inevitably be put out each day in the west, since they are not seen to return to the place whence they started, and they must be rekindled some hours afterwards in the east. In the days of Augustus, Cleomedes still finds himself obliged to combat these Epicurean ideas about the setting and rising of the sun and stars. "These stupid ideas," he says, "have no other foundation than an old woman's story--that the Iberians hear each night the hissing noise made by the burning sun as it is extinguished, like a hot iron in the waters of the ocean." Modern travellers have shown us that similar ideas about the support of the earth have been entertained by more remote people. Thus, in the opinion of the Greenlanders, handed down from antiquity to our own days, the earth is supported on pillars, which are so consumed by time that they often crack, and were it not that they are supported by the incantations of the magicians, they would long since have broken down. This idea of the breaking of the pillars may possibly have originated in the known sinking of the land beneath the sea, which is still going on even at the present day.

[Ill.u.s.tration: FIG. 31.--EGYPTIAN REPRESENTATION OF THE EARTH.]

An ancient Egyptian papyrus in the library of Paris gives a very curious hieroglyphical representation of the universe. The earth is here figured under the form of a reclining figure, and is covered with leaves. The heavens are personified by a G.o.ddess, which forms the vault by her star-bespangled body, which is elongated in a very peculiar manner. Two boats, carrying, one the rising sun, and the other the setting sun, are represented as moving along the heavens over the body of the G.o.ddess. In the centre of the picture is the G.o.d, Maon, a divine intelligence, which presides over the equilibrium of the universe.

We will now pa.s.s on from the early ideas of the general shape and situation of the world to inquire into the first outlines of geographical knowledge of details.

Of all the ancient writings which deal with such questions, the Hebrew Scriptures have the greatest antiquity, and in them are laid down many details of known countries, from which a fair map of the world as known to them might be made out. The prophet Esdras believed that six-sevenths of the earth was dry land--an idea which could not well be exploded till the great oceans had been traversed and America discovered.

More interesting, as being more complete, and written to a certain extent for the very purpose of relating what was known of the geography of the earth, are the writings of the oldest Grecian poets. The first elements of Grecian geography are contained in the two national and almost sacred poems, the _Iliad_ and _Odyssey_. So important have these writings been considered in regard to ancient geography, that for many centuries discussions have been carried on with regard to the details, though evidently fict.i.tious, of the voyage of Ulysses, and twenty lines of the _Iliad_ have furnished matter for a book of thirty volumes.

The shield of Achilles, forged by Vulcan and described in the eighteenth book of the _Iliad_, gives us an authentic representation of the primitive cosmographical ideas of the age. The earth is there figured as a disc, surrounded on all sides by the _River Ocean_. However strange it may appear to us, to apply the term _river_ to the ocean, it occurs too often in Homer and the other ancient poets to admit of a doubt of its being literally understood by them. Hesiod even describes the sources of the ocean at the western extremity of the world, and the representation of these sources was preserved from age to age amongst authors posterior to Homer by nearly a thousand years. Herodotus says plainly that the geographers of his time drew their maps of the world according to the same ideas; the earth was figured with them as a round disc, and the ocean as a river, which washed it on all sides.

The earth's disc, the _orbis terrarum_, was covered according to Homer by a solid vault or firmament, beneath which the stars of the day and night were carried by chariots supported by the clouds. In the morning the sun rose from the eastern ocean, and in the evening it declined into the western; and a vessel of gold, the mysterious work of Vulcan, carried it quickly back by the north, to the east again. Beneath the earth Homer places, not the habitation of the dead, the caverns of Hades, but a vault called Tartarus, corresponding to the firmament. Here lived the t.i.tans, the enemies of the G.o.ds, and no breath of wind, no ray of light, ever penetrated to this subterranean world. Writers subsequent to Homer by a century determined even the height of the firmament and the depth of Tartarus. An anvil, they said, would take nine days to fall from heaven to earth, and as many more to fall from earth to the bottom of Tartarus. This estimate of the height of heaven was of course far too small. If a body were to fall for nine days and nights, or 777,600 seconds under the attraction of the earth, it would only pa.s.s over 430,500 miles, that is not much more than half as far again as the moon. A ray of light would only take two seconds to pa.s.s over that distance, whereas it takes eight minutes to reach us from the sun, and four hours to come from Neptune--to say nothing of the distance of the stars.

The limits of the world in the Homeric cosmography were surrounded by obscurity. The columns of which Atlas was the guardian were supported on unknown foundations, and disappeared in the systems subsequent to Homer.

Beyond the mysterious boundary where the earth ended and the heavens began an indefinite chaos spread out--a confused medley of life and inanity, a gulf where all the elements of heaven, Tartarus, and earth and sea are mixed together, a gulf of which the G.o.ds themselves are afraid.

Ideas such as these prevailed long after geometers and astronomers had proved the spherical form of the globe, and they were revived by the early Christian geographers and have left their trace even on the common language of to-day.

[Ill.u.s.tration: FIG. 32.--HOMERIC COSMOGRAPHY.]

The centre of the terrestrial disc was occupied by the continent and isles of Greece, which in the time of Homer possessed no general name.

The centre of Greece pa.s.sed therefore for the centre of the whole world; and in Homer's system it was reckoned to be Olympus in Thessaly, but the priests of the celebrated Temple of Apollo at Delphi (known then under the name of Python) gave out a tradition that that sacred place was the real centre of the habitable world.

The straits which separate Italy from Sicily were so to speak the vestibule of the fabulous world of Homer. The threefold ebb and flow, the howling of the monster Scylla, the whirlpools of Charybdis, the floating rocks--all tell us that we are quitting here the region of truth. Sicily itself, although already known under the name of _Trinacria_, was filled with marvels; here the flocks of the Sun wandered in a charming solitude under the guardianship of nymphs; here the Cyclops, with one eye only, and the anthropophagous Lestrigons scared away the traveller from a land that was otherwise fertile in corn and wine. Two historical races were placed by Homer in Sicily, namely the _Sicani_, and the _Siceli_, or _Siculi_.

To the west of Sicily we find ourselves in the midst of a region of fables. The enchanted islands of Circe and Calypso, and the floating island of Eolus can no longer be found, unless we imagine them to have originated, like Graham's Island in this century, from volcanic eruptions or elevations, and to have disappeared again by the action of the sea.

The Homeric map of the world terminated towards the west by two fabulous countries which have given rise to many traditions among the ancients, and to many discussions among moderns. Near to the entrance of the ocean, and not far from the sombre caverns where the dead are congregated, Ulysses found the _Cimmerians_, "an unhappy people, who, constantly surrounded by thick shadows, never enjoyed the rays of the sun, neither when it mounted the skies, nor when it descended below the earth." Still farther away, and in the ocean itself, and therefore beyond the limits of the earth, beyond the region of winds and seasons, the poet paints for us a Fortunate Land, which he calls _Elysium_, a country where tempests and winter are unknown, where a soft zephyr always blows, and where the elect of Jupiter, s.n.a.t.c.hed from the common lot of mortals, enjoy a perpetual felicity.

Whether these fictions had an allegory for their basis, or were founded on the mistaken notions of voyagers--whether they arose in Greece, or, as the Hebrew etymology of the name Cimmerian might seem to indicate, in the east, or in Phenicia, it is certain that the images they present, transferred to the world of reality, and applied successively to various lands, and confused by contradictory explanations, have singularly embarra.s.sed the progress of geography through many centuries. The Roman travellers thought they recognised the Fortunate Isles in a group to the west of Africa, now known as the Canaries. The philosophical fictions of Plato and Theopompus about Atlantes and Meropis have been long perpetuated in historical theories; though of course it is possible that in the numerous changes that have taken place in the surface of the earth, some ancient vast and populous island may have descended beneath the level of the sea. On the other side, the poetic imagination created the _Hyperboreans_, beyond the regions where the northern winds were generated, and according to a singular kind of meteorology, they believed them for that reason to be protected from the cold winds.

Herodotus regrets that he has not been able to discover the least trace of them; he took the trouble to ask for information about them from their neighbours, the _Arimaspes_, a very clear-sighted race, though having but a single eye; but they could not inform him where the Hyperboreans dwelt. The Enchanted Isles, where the Hesperides used to guard the golden fruit, and which the whole of antiquity placed in the west, not far from the Fortunate Isles, are sometimes called Hyperborean by authors well versed in the ancient traditions. It is also in this sense that Sophocles speaks of the Garden of Phoebus, near the vault of heaven, and not far from the _sources of the night_, _i.e._ of the setting of the sun.

Avienus explains the mild temperature of the Hyperborean country by the temporary proximity of the sun, since, according to the Homeric ideas, it pa.s.ses during the night by the northern ocean to return to its palace in the east. This ancient tradition was not entirely exploded in the time of Tacitus, who states that on the confines of Germany might be seen the veritable setting of Apollo beyond the water, and he believes that as in the east the sun gives rise to incense and balm by its great proximity to the earth, so in the regions where it sets it makes the most precious of juices to transude from the earth and form amber. It is this idea that is embedded in the fables of amber being the tears of gold that Apollo shed when he went to the Hyperborean land to mourn the loss of his son aesculapius, or by the sisters of Phaeton, changed into poplars; and it is denoted by the Greek name for amber, _electron_--a sun-stone. The Grecian sages, long before the time of Tacitus, said that this very precious material was an exhalation from the earth that was produced and hardened by the rays of the sun, which they thought came nearer to the earth in the west and in the north.

Florus, in relating the expedition of Decimus Brutus along the coast of Spain, gives great effect to the Epicurean views about the sun, by declaring that Brutus only stopped his conquests after having witnessed the actual descent of the sun into the ocean, and having heard with horror the terrible noise occasioned by its extinction. The ancients also believed that the sun and the other heavenly bodies were nourished by the waters--partly the fresh water of the rivers, and partly the salt water of the sea. Cleanthes gave the reason for the sun returning towards the equator on reaching the solstices, that it could not go too far away from the source of its nourishment. Pytheas relates that in the Island of Thule, six days' journey north of Great Britain, and in all that neighbourhood, there was no land nor sea nor air, but a compound of all three, on which the earth and the sea were suspended, and which served to unite together all the parts of the universe, though it was not possible to go into these places, neither on foot nor in ships.

Perhaps the ice floating in the frozen seas and the hazy northern atmosphere had been seen by some navigator, and thus gave rise to this idea. As it stands, the history may be perhaps matched by that of the amusing monk who said he had been to the end of the world and had to stoop down, as there was not room to stand between heaven and earth at their junction.

Homer lived in the tenth century before our era. Herodotus, who lived in the fifth, developed the Homeric chart to three times its size. He remarks at the commencement of his book that for several centuries the world has been divided into three parts--Europe, Asia, and Libya; the names given to them being female. The exterior limits of these countries remained in obscurity notwithstanding that those boundaries of them that lay nearest to Greece were clearly defined.

One of the greatest writers on ancient geography was Strabo, whose ideas we will now give an account of. He seems to have been a disciple of Hipparchus in astronomy, though he criticises and contradicts him several times in his geography. He had a just idea of the sphericity of the earth; but considered it as the centre of the universe, and immovable. He takes pains to prove that there is only one inhabited earth--not in this refuting the notion that the moon and stars might have inhabitants, for these he considered to be insignificant meteors nourished by the exhalations of the ocean; but he fought against the fact of there being on this globe any other inhabited part than that known to the ancients.