Of course there have been always fantastic fancies put forth about the solar system, but they are more amusing than instructive. Some have said that there is no sun, moon, or stars, but that they are reflections from an immense light under the earth. Some savage races say that the moon when decreasing breaks up into stars, and is renewed each month by a creative act. The Indians used to say that it was full of nectar which the gods ate up when it waned, and which grew again when it waxed. The Brahmins placed the earth in the centre, and said that the stars moved like fishes in a sea of liquid. They counted nine planets, of which two are invisible dragons which cause eclipses; which, since they happen in various parts of the zodiac, show that these dragons revolve like the rest. They said the sun was nearer than the moon, perhaps because it is hotter and brighter. Berosus the Chaldean gave a very original explanation of the phases and eclipses of the moon. He said it had one side bright, and the other side just the colour of the sky, and in turning it represented the different colours to us.
Before concluding this chapter we may notice what information we possess as to the origin of the names by which the planets are known. These names have not always been given to them, and date only from the time when the poets began to associate the Grecian mythology with astronomy. The earlier names had reference rather to their several characters, although there appear to have been among every people two sets of names applied to them.
The earliest Greek names referred to their various degrees of brilliancy: thus Saturn, which is not easily distinguished, was called Phenon, or that which appears; Jupiter was named Phaëton, the brilliant; Mars was Pysoïs, or flame-coloured; Mercury, Stilbon, the sparkling; Venus, Phosphorus; and Lucifer, the light-bearer. They called the latter also Calliste, the most beautiful. It was also known then as now under the appellations of the morning star and evening star, indicating its special position.
With the ancient Accadians, the planets had similar names, among others. Thus, "Mars was sometimes called the vanishing star, in allusion to its recession from the earth, and Jupiter the planet of the ecliptic, from its neighbourhood to the latter" (Sayce). The name of Mars raises the interesting question as to whether they had noticed its phases as well as its movements—especially when, with reference to Venus, it is recorded in the "Observations of Bel," that "it rises, and in its orbit duly grows in size." They had also a rather confusing system of nomenclature by naming each planet after the star that it happened to be the nearest to at any point of its course round the ecliptic.
Among less cultivated nations also the same practice held, as with the natives of South America, whose name for the sun is a word meaning it brings the day; for the moon, it brings the night; and for Venus, it announces the day.
But even among the Eastern nations, from whom the Greeks and Romans borrowed their astronomical systems, it soon became a practice to associate these planets with the names of the several divinities they worshipped. This was perhaps natural from the adoration they paid to the celestial luminaries themselves on account of their real or supposed influence on terrestrial affairs; and, moreover, as time went on, and heroes had appeared, and they had to find them dwelling-places in the heavens, they would naturally associate them with one or other of the most brilliant and remarkable luminaries, to which they might suppose them translated. Beyond these general remarks, only conjectures can be made why any particular divinity should among the Greeks be connected with the several planets as we now know them. Such conjectures as the following we may make. Thus Jupiter, the largest, would take first rank, and be called after the name of the chief divinity. The soft and sympathising Venus—appearing at the twilight—would well denote the evening star. Mars would receive its name from its red appearance, naturally suggesting carnage and the god of war. Saturn, or Kronos, the god of time, is personified by the slow and almost imperceptible motion of that remote planet. While Mercury, the fiery and quick god of thieves and commerce, is well matched with the hide-and-seek planet which so seldom can be seen, and moves so rapidly.
These were the only planets known to the ancients, and were indeed all that could be discovered without a telescope. If the ancient Babylonians possessed telescopes, as has been conjectured from their speaking, as we have noticed above, of the increase of the size of Venus, and from the finding a crystal lens among the ruins of Nineveh, they did not use them for this purpose.
The other planets now known have a far shorter history. Uranus was discovered by Sir William Herschel on the 13th of March, 1781, and was at first taken for a comet. Herschel proposed to call it Georgium Sidus, after King George III. Lalande suggested it should be named Herschel, after its discoverer, and it bore this name for some time. Afterwards the names, Neptune, Astrœa, Cybele, and Uranus were successively proposed, and the latter, the suggestion of Bode, was ultimately adopted. It is the name of the most ancient of the gods, connected with the then most modern of planets in point of discovery, though also most ancient in formation, if recent theories be correct. Neptune, as everybody knows, was calculated into existence, if one may so speak, by Adams and Leverrier independently, and was first seen, in the quarter indicated, by Dr. Galle at Berlin, in September, 1846, and by universal consent it received the name it now bears.
There are now also known a long series of what are called minor planets, all circulating between Mars and Jupiter, with their irregular orbits inextricably mingled together. Their discovery was led to in a remarkable manner. It was observed that the distances of the several planets might approximately be expressed by the terms of a certain mathematical series, if one term was supplied between Mars and Jupiter—a fact known by the name of Bode's law. When the new planet, Uranus, was found to obey this law, the feeling was so strong that there must be something to represent this missing term, that strong efforts were made to discover it, which led to success, and several, whose names are derived from the minor gods and goddesses, are now well known.
