Solar System
3 of the 7 encyclopedias on this shelf carry an entry for Solar System. Both are reproduced below, so you can see where they agree and where they differ.
Collier's New Encyclopedia (1921)
the sun and all the bodies, by whatever name they may be called, which periodically revolve round the sun as a center. Visible to us are seven distinct orders or systems of revolving worlds. They are the zodiacal light, whatever that may be, the planetary, the satellitic, the meteoric, the cometary, the stellar, and the nebular systems. All but the latter two belong to our solar system. The limits of the planetary system, as far as known, are Mercury, the nearest to the sun, and Neptune, the most distant. This limit does not include Diameter Density Planet (miles) (earth's 1) Mercury 2,770 0.56 Venus 7,700 0.82 Earth 7,918 1.00 Planetoid Eros 20 ? Mars 4,230 0.71 Planetoid Ceres 480 ? Jupiter 86,500 0.24 Saturn 73,000 0.13 Uranus 31,900 0.22 Neptune 34,800 0.20 the hypothetical intra-Mercurial planets, discovered during the total solar eclipses, in 1878, by Watson and Swift. Its cometary extent is not known, and never will be, as several comets have computed periods of over 1,000,000 years, and even their aphelia reach only a step toward even the nearest star. The sun's far-reaching power, of course, extends to half way to the stars, and it is not an unreasonable supposition to suppose that there are comets whose aphelia extend that far, and if so, their periodic times must be several million years. The bodies as far as known that are denizens of our solar system are the sun (the center), the planets of Mercury, Venus, earth with one satellite, Mars with 2 satellites, 428 asteroids, Jupiter and 5 satellites, Saturn with 5 rings and 8 satellites, Uranus with 4, and Neptune with 1, also Halley's, Pons', and Olbers' comets of long period, and about 25 of short period, ranging from 3.3 years (Encke's) to 13.78 years, commonly, but unjustly, called Tuttle's comet. It was discovered by Méchain in 1790. To the list must be added 200 or more meteoric rings, which, while the earth is passing through them, produce the star showers. Every member of the solar system, be it planet, satellite, meteoroid or comet, moves in an orbit called an ellipse, of greater or lesser eccentricity. There is not a heavenly body known to man that moves in a circle. The planets and satellites revolve in elliptic orbits, while the comets move some in elliptic and others in parabolic and hyperbolic orbits. Those moving in either of the latter two can never return, as the two branches of their paths do not meet to form a closed curve as does the ellipse. For adopting the ellipse instead of the circle for planetary revolution the world is indebted to the genius of Kepler, who by the first of his three laws brought harmony out of confusion. The three laws of Kepler, as enunciated by him, are: (1) The planets move in ellipses, having the sun in one of the foci. (2) The radius vector of each planet describes equal areas PRINCIPAL ELEMENTS OF THE SOLAR SYSTEM Mean distance Period of from sun revolu- (millions of Mass tion (earth's 1) (days) miles) 0.024 35.7 88 0.82 67.2 225 92.9 365 1 135.1 643 ? 0.105 141.5 687 257.1 1,681 ? 318 483.3 4,333 10,759 93 886.0 15 30,688 1,781.9 2,791.6 60,181 17 in equal times. (3) The squares of their periodic times are proportional to the cubes of their mean distances from the sun. As all heavenly bodies hang suspended on nothing throughout all space each being attracted by all the others it results that they must move, and, while the motions of the planets are easily noticeable in a few hours, and even min utes, it requires to detect motion in the stars long-continued observation with instruments of great delicacy and power to ascertain that they have any motion at all, so far away are they. No planet whose orbit is interior to the earth's can ever assume the crescent phase, or rise when the sun sets, or be on the meridian at midnight, or transit the sun. On the other hand, those whose orbits are exterior to ours can never assume the crescent and half-moon phase, and are the only ones that can ever be in opposition, rising at sunset.
An Encyclopaedia of Occultism (1920)
Theosophists have special doctrines as to the formation of solar systems. They start by postulating the existence of all pervading ether, or, as it is termed in occult chemistry (q.v.) koilon, an ether which is quite imperceptible to ordinary senses and indeed even to clairvoyants except the most highly-developed. It is, despite its diffusion, of extreme density. The Deity intending to create a universe invests this ether with his divine force, whereupon it becomes the constituent of matter in the shape of minute drops or bubbles, and of this the universe with its solar systems is formed. First a mass is aggregated by the appropriate agitation of these drops, and to this mass is imparted a rotatory motion. The mass thus formed, of course, contains the matter from which will be formed all the seven worlds, the existence of which Theosophy teaches, and it may be well here to observe that these worlds are not separate in the manner we usually conceive separate worlds to be, but inter-penetrate each other. The substance in its original form is of the texture of the first world, and in order to create the texture of the secondand lower-world the Deity sets up a vast number of rotatory agitations into each of which is collected 49 atoms arranged in a certain way, sufficient of the first atom having been left to form the first world. This process continues six times, the atoms of the succeeding lower worlds being formed from those of the world immediately higher and each time of a multiple of 49 atoms. Gradually and with the passing of long ages, the aggregation, which contains the atoms of all seven worlds completely intermingled, contracts and becomes more closely knit until it forms a nebula which eventually attains the flat, circular form familiar to students of astromony. Towards the centre it is much more dense than at the fringes, and in the process of flattening and because of the initial revolving motion, rings are formed encircling the centre. From these rings the planets are formed, and after the further passing of ages, it is possible for human life to exist on them. The various worlds as has been said, penetrate each other substantially within the same bounds, the exceptions being the worlds of finer texture which extend beyond those relatively more dense. The names of the worlds are: the first which has not as yet been experienced by man-the Divine; the second, the Monadic whence come the impulses that form man; the third, the Spiritual, the highest world which man has as yet been able to experience; the fourth, the Intuitional, the fifth, the Mental; the sixth, the Emotional (Astral) world; and the seventh is the world of matter as matter is familiar to us. Reference is made to the various articles dealing more fully with these worlds as follows :- " دو دو Adi Plane, See " Divine World and Solar System " Annpadaka Monadic " " Atmic or Movanic Spiritual Buddhic Inutitional " " Astral Emotional " دو دو وو دو دو وو " " Solomon
Aiton's Encyclopedia (1910)
. See Sun