Saturn, 85,782 miles in diameter or about 1000 times as large as the Earth, is still a more remote planet from the Sun, round which he revolves in about 30 of our years, at the distance of 916 millions of miles. He moves in his orbit at the rate of 22,298 miles every hour, and upon his axis in 10h. 16m. by this swift revolution on his axis his figure becomes oblate in the proportion of 11 to 10, and his atmosphere and vapours are drawn like a quintuple belt of 3 darker parts and 2 lighter upon his body. Saturn is attended by seven Satellites, the outermost has been long known to have a period of apparent augmentation and diminution, and hence probably to have a revolution on its axis, and be composed of land and water.

A large, broad, double, and luminous ring of 200,157 miles diameter, surrounds Saturn, at a distance from the planet equal to the breadth of the ring.—This ring inclines about 30 degrees to the plane of the ecliptic, and must appear like a great arch of light to the inhabitants of Saturn. It has a revolution every eleven hours on an axis perpendicular to its plane, and keeps parallel to itself at all times; hence it disappears twice every 30 years, when its edge is presented to us; the Sun shines for near 15 of our years together on the northern plane of the ring; and then leaving it, illumines the southern side for the same period; so there is but one day and one night on each side of the ring, but each will be of 15 years continuance without intermission.

The Sun’s direct light being but about a 90th part so strong to Saturn as to the Earth, this ring is no doubt intended to increase it, by reflecting a very considerable portion upon the planet, which added to that from his seven Satellites, must render him a very comfortable abode for rational and brute inhabitants.

The Georgium Sidus, or Georgian Planet (so called by Dr. Herschell, its ingenious and indefatigable discoverer) makes the seventh in the order of the system; the other planets we have described have been known as such to the highest antiquity, but from its extreme smallness, this has escaped ascertainment till the year 1781, although it had been recognized as a very minute star by several astronomers. It is near twice Saturn’s distance from the Sun, and will be near eighty-two years and six months in going round him; is of a pale colour, and much larger in its telescopic appearance than the fixed stars, being 100 times as large as the Earth, or 37,230 miles diameter, and, on a clear evening, is visible to the naked eye. The Dr. has discovered six satellites to this planet, some of which are said to move retrograde. As familiarity is the principal design of this Treatise and Lecture, it may be useful to exhibit the distances of the planets from the Sun in the most concise form, and in numbers they will stand thus:—if the distance from the Sun of

Mercury—Venus—Earth—Mars—Jupiter—Saturn—Georgium Sidus
is 4will be 710155295190

or, if a body projected from the Sun should continue to fly at the rate of 480 miles per hour, (which is about the swiftness of a cannon-ball), it could reach the orbit of Mercury in 9 years, Venus in 16 years, the Earth in 23 years, Mars in 34 years, Jupiter in 118 years, Saturn in 216 years, and the Georgium Sidus in 432 years.

These we consider as the regular bodies of our system; so regular, indeed, that every phænomenon respecting them is calculated for years before hand, and it is almost considered as a criminal error to be a minute of time wrong in the calculation. But we are sometimes visited by Comets, which may also be recognized as a part of our system: of these our knowledge is very imperfect. By supposing that the same Comet has appeared at equal intervals of time; by observing that, like the planets, they describe equal areas in equal times; and by having three points in an ellipsis given to make out its eccentricity; from these data it was natural for mathematicians to suppose they could calculate the return of all Comets that had been scientifically observed: but the actual return even of that conspicuous one expected by Dr. Halley, has been thought by some not to be sufficiently ascertained: yet, on examining the balance of probability, as stated by Maupertius, Lalande, Messire and Martin, for its re-appearance, probably this doubt will be greatly lessened, if not removed. As new Comets are almost perpetually appearing, on which calculation hitherto has been silent, there is reason to expect, in a proper period of time, an adequate number of observations to decide the question, whether in general they revolve at stated times, or traverse our system without probability of return. Perhaps Comets of each description time and observation may confirm to us. We know that Comets accompanied with tails come very near the Sun, and from all quarters of the Heavens! that the tails keep opposite to the Sun; consequently they are only visible to us when seen obliquely to the Sun. Thus the Comet of August, 1797, was observed to have little or no train during any part of its appearance; but a faint hazy light diffused round it; these trains, like electrical and borealean light, do not refract the light of the fixed stars, &c. The appearance of the Comet of 1682, is copied in the Eidouranion. It descends from the top of the Machine; its train increasing in length and lustre till it arrives at the Sun, diminishing as it ascends. Its orbit is so eccentric that the small part of it visible is not sensibly to be distinguished from the parabolic curve; and in this representation it finally disappears in the roof of the Theatre; it being impossible, if its return were ascertained, to represent the extent of such an orbit, and its motion in it, with any degree of suitable proportion. The velocity of such of these as approach nearest to the Sun, particularly of the Comet of 1680, (whose appearance was tremendous) exceeds any swiftness that falls within observation; except that of the rays of light; it being nearly 2000 times greater than the swiftness of a cannon-ball, at the instant of its discharge; yet scarcely a thousandth part of the velocity of light passing from the Sun[4]. This Comet approached to within 40,000 miles of the Sun’s surface, and was calculated to be heated 2000 times hotter than red hot iron; a globe of iron the size of the Earth in this heat, would be 50,000 years in cooling. These amazing visiters, whom philosophy contemplates with awe very different from that terror with which superstition had long viewed them, moving in such amplitude of space, so numerous as they are, and so great as some of them, must have functions assigned to them proportionally important: either occasionally of terrific revolution; or more generally of recruiting the atmosphere of the planets in their successive appulse to any of them, and supplying the diminution of the solar fires. Perhaps too they are useful in preventing the central tendency of the planets to the Sun, from increasing more than in a certain degree; so that the apparent disturbances, thus produced, will be part of the necessary order and harmony of the system.

It is probable (though their orbits are so much oblique in all directions to those of the planets, that it can rarely happen) that Comets may be instrumental to great shocks; either by direct collision, the effect of which, considering the velocity and mass of some of them cannot be estimated, or by near approach: and of this latter a possible result, and such as seems, in one instance at least, to have already taken place, is noticed in the Remarks annexed to this account of the Eidouranion. But the philosophic observer will have this reflection presented to him from the phænomena of the Universe; that the apparently disturbing and destructive powers are secondary and subservient; while those of the preserving and meliorating kind are primary, continued, and universal. And those incidental causes of a melancholy and distressing aspect, when resolved into their ultimate tendency and necessary effects, manifest themselves, in so far as we can trace them, to be parts essential to the system of pure and perfect benevolence. Stability and duration are stamped on the Universe, and the imagination is lost in the immensity of the prospects; and whether we turn to the past or to the future, our conception vainly pants to grasp the idea of boundless Eternity.

But when we launch in idea into infinite space, and contemplate the systems without number that fill it; here indeed we have a subject truly worthy of the Deity! Whoever supposes the fixed stars placed in a concave sphere, as they appear to us, must have a narrow and contracted idea of the Supreme Being; for one star appears large and another small, because one is immensely distant from us in comparison of another. Through Dr. Herschell’s large telescope many fixed stars appear double: the Polar star is double; (but they are only stars at different distances from us appearing nearly in the same line) some appear like a topaz, others azure, others red; all are round, and many as perfectly defined as a shilling is on black cloth. By telescopes we formerly could see three times the number we can by the naked eye; and now, telescopes having received further improvement, in the most crouded part of the milky way, 116,000 have passed before the instrument in a quarter of an hour. The Nebula of Andromeda must be composed of the united lustre of many millions of stars. Agreeably to this, Dr. Herschell has noticed single nebulous stars surrounded with a faint equable whiteness; such as a system of Planets viewed at that distance from us might be supposed to give: others he has seen, which have the appearance of yet unformed systems. And there are, we may presume, points of view, in the immensity of the Universe, in which all the fixed stars, accessible to the eye or telescope from this station of ours, and all the inconceivable space, through which they extend, vanish into a nebula, and almost an indiscernible point. Such is the order and greatness of that Empire, which these Discoveries, the farther they are pursued, must for ever more and more present to our increasing admiration. Such the relation of parts so astonishingly remote! Such the unity of intelligence, power, and preserving goodness which pervades the whole! And why may not stars be so remote, that their light may not have reached the Earth even since the creation! We know that light takes more time in travelling from the nearest stars to us, than we in making a West India voyage, (which is usually performed in six weeks) a sound would not arrive to us from thence in 50,000 years, nor a cannon-ball in a much longer time. The Sun’s light could not therefore reach the fixed stars, and be reflected back again with their lustre; of course they shine by their own light—if so, they shine as our Sun, and consequently are Suns themselves.—Now, as a principal of uniformity runs through the variety of nature, it is reasonable to conclude these Suns to be centres of systems like ours; and destined for the same noble purposes, viz. that of giving light, heat, and vegetation, to various worlds that revolve round them, but which are too remote for discovery, even with our best telescopes! This idea is infinitely too great for the human mind; or indeed for that of any created Being! For how inadequate must the utmost stretch of finite faculties be to represent infinity! The stars, disposed in constellations, and surrounded by concentric circles, may perhaps assist the imagination a little: The attempt in Scene V. if not admired, we hope will be forgiven. But was it possible we could actually take our flight into infinite space, or be borne on the wings of lightning, to the most distant fixed Star we can now see, even there, perhaps, we should find ourselves on the confines of creation, and see as many stars before us as we left behind! For space has neither top nor bottom in it: it is a circle whose centre is every where, but whose circumference is no where! Even systems themselves may have revolutions round one another; and account for that difference of distance that we are constantly observing to arise amongst the fixed stars; for new stars appear, rise into magnitude, and then diminish and disappear, which would also be accounted for by supposing that our Sun himself is in progressive motion towards some part of infinite space, and carrying his system of worlds along with him. Stars of the first magnitude, in Flamsted’s time, dwindle into those of the third or fourth, in our time. Some of the stars change their magnitude periodically: as Algol, in Medusa’s Head, which rises from the third magnitude to the second, in two days and twenty-one hours.—Where such periodical disappearances are short, they have been referred with probability to quick revolutions of such stars on their axis, with part of their disk opaque; or to the regular intervention of some very considerable Planet to intercept them from us. But re-appearances of this kind, after very long intervals, would indicate rather a revolution in a great orbit. By analogy we conclude, that at a proper distance our Sun would dwindle into a fixed Star among the rest, and his system of worlds disappear. Now as we see that almost every particle of our globe swarms with life and animals, we cannot suppose the other bodies of our system to be only intended as a faint spangle for mortals to gaze at; more especially as they are as well calculated for inhabitants as ours, revolving as regularly round the same Sun, and seeming to have every other convenience for rational and brute inhabitants[5]. But to carry this idea into infinite space; to recognize Suns and Systems, above us, below us, to the East, the West, the North, the South; to consider each Sun as the centre of a system like ours, and every world inhabited!—In short, the astonished fancy turns round, and is entirely lost and sunk in the abyss of nature! Well might the Psalmist say, that, “The heavens declare the glory of God, and the firmament sheweth his handy work.” Well might he express himself as overwhelmed with the idea of the power and omnipresence of the Deity; since all our discoveries serve only to convince us, that a progress of inexpressible extent, continued through ages without number, would find us every where, as here, surrounded with his infinite energy, eternity, and immensity, filled with his vital presence.