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•ne ©dipse of these moons, the motion of light was ascertained; and they are found to be of essential use in determining the longitude of places on the surface of our globe. This planet, if seen from its nearest moon, will present a surface a thousand times as large as our moon does to us, and will appear in the form of a crescent, a halfmoon, a gibbous phase, and a full-moon, in regular succession, every 24 hours. Jupiter's axis being nearly perpendicular to his orbit, he has no sensible change of seasons, such as re experience on the earth. Were we placed on ^e surface of this planet, with the limited powers of vision we now possess, our earth and moon would entirely disappear, as if they were blotted out from the map of creation; and the inhabitants of these regions must have much better eyes than ours, if they know that there is such a globe as tfae earth in the universe.
The planet Saturn.—This planet is 900 millions of miles distant from the sun, being ncarfy double the distance of Jupiter. Its diameter is 79,000 mites, and, consequently, it is more than *ine hundred times the bulk of the earth. It takes 29} years to complete its revolution about the sun; but its diurnal motion is completed in ten hours and sixteen minutes; so that the year in this planet is nearly thirty times the length of ours, while the day is shorter, by more than onehalf. The year, therefore, contains about twenty-five thousand one hundred and fifty day*, or periods of its diurnal rotation, which is equal to 10 759 of our days. Saturn is of a spheroidal figure, or somewhat of the shape of an orange; sis equatorial being more than six thousand miles longer than his polar diameter. His surface, like that of Jupiter, is diversified with belts and dark spots. Dr. Herachel, at certain times, perceived five belts on his surface, three of which were dark, and two bright. The dark belts had a yellowish tinge, and generally covered a larger cone of the disk of Saturn, than the bells of Jupiter occupy upon his surface. On account of the prett distance of this planet from the sun, the light it receives from that luminary is only the ninetieth part of what we enjoy; but, by calculation, it is found, that this quantity is a thousand times greater than the light which the full moon affords to us. Bosidre, it is surrounded by no fewer than seven moons, which supply it with light in the absence of the sun. Five of these moons were discovered during the seventeenth century, by Huygens and Cassini; and the sixth and seventh were discovered by Dr. Herschel, in 1789, soon after his large forty feet reflecting telescope was constructed. These moons, and also those which accompany Jupiter, are estimated to be not less than the earth in magnitude, mod are found, like our moon, to revolve round their axis iu the same time in which they revolve kbout their respective primaries.
Ring* of Saturn.—The most extraordinary
circumstance connected with this planet, is, the phenomenon of a double ring, which surrounds its body, but no where touchos it, being thirty thousand miles distant from any part ot the planet, and is carried along with the planet in iu circuit round the sun. This is the most singular and astonishing object in the whole range of the planetary system; no other planet being found environed with so wonderful an appendage j and the planets which may belong to other systems, being placed beyond the reach of our observations, no idea can be formed of the peculiar apparatus with which any of-them may be furnished. This double ring consists of two concentric rings, detached from each other; the innermost of which is nearly three times as broad as the outermost. The outside diameter of the esierior ring is 204,000 miles ; and, consequently, its circumference will measure six hundred and forty thousand miles, or eighty times the diameter of our globe. Its breadth is 7,200 miles, or nearly the diameter of the earth. Were four hundred and fifty globes, of the size of the earth, placed close to one another, on a plane, this immense ring would enclose the whole of them, together with all the interstices, or open spaces between the difTerent globes. The outs toe diameter of the innermost ring is 184,000 miles, and its breadth twenty thousand miles, or about 2} times broader than the diameter of the earth. The dark space, or interval, between the two rings, is 2,800 miles. The breadth of both tho rings, including the dark space between them, is thirty thousand mites, which is equal to the distance of the innermost ring from Uie body of Saturn.
The following figure represents a view of Saturn and his rings, as they would appear, were our eye perpendicular to one of the planes of those rings; but our eye is never so much elevated above either plane, as to have the visual ray standing at right angles to it; it is never elevated more than 30 degrees above the planes of the rings. When we view Saturn through a telescope, we always see the ring at an oblique angle, so that it appears of an oval form, the outward circular rim being projected into an ellipsis more or less oblong, according to tho different degrees of obliquity with which it is viewed, as will be seen in the figure of Saturn in the copperplate engraving.
These rings cast a deep shadow upon the planet, which proves that they are not shining fluids, but composed of solid matter. They appear to be possessed of a higher reflective power than the surface of Saturn; as the light reflected by them is more brilliant than that of the planet. One obvious use of Uiis double ring is, to reflect light upon the planet, in the absence of the sun; what other purposes it may be intended to subserve, in the system of Saturn, is, at present, to us unknown. The sun illuminates one side of it during fifteen years, or one-half of the period of the planet's revolution; and during the next fifteen years, the other side is enlightened in its turn. Twice in the course of thirty years, there is a short period, during which oei" her side is enlightened, and when, of course, it ceases to be visible ;—namely, at the time when the sun ceases to shine on one side, and is about to shine on the other. It revolves round its axis, and, consequently, around Saturn, in ten hours and a half, which is at the rate of a thousand miles in a minute, or fifty-eight times swifter than the earth's equator. When viewed from tho middle zone of the p'anet, in the absence of the sun, the rings will appear like vast luminous arches, extending along the canopy of heaven, from the eastern to the western horizon; having an apparent breadth equal to a hundred times the apparent diameter of our moon, and will be seen darkened about the middle, by the shadow of Saturn.*
There is no other planet in the solar system, whose Armament win present such a variety of splendid and magnificent objects, as that of Saturn. The various aspects of his seven moons, one rising above the horizon, while another is setting, and a third approaching to the meridian;
'See the engraving, fig. 7, which represents a view of D,sappearance which the rlngsnnd moons ef Saturn will exhibtt, in certain cases, about midnight, when beheld from a point so or 30 degrees north from his equator. The shade on the upper pirt of thn rings represents the shadow of the body of Saturn. The shadow will appear to move gradually 4> the west as the morning approaches.
one entering into an eclipse), and Shutffner emerging from it; one appearing as a crescent, and another with a gibbous phase; and sometimes the whole of them shining in the same hemisphere, in one bright assemblage; the majestic motions of the rings,—at one time illuminating the sky with their splendour, and eclipsing the stars; at another, casting a deep shade over certain regions of the planet, and unveiling to view the wonders of the starry firmament—are scenes worthy of the majesty of the Divine Being to unfold, and of rational creatures to contemplate. Such magnificent displays of wisdom and omnipotence lead us to conclude that the numerous splendid objects connected with this planet were not created merely to shed their lustre on naked rocks and barren sands; but that an immense population of intelligent beings is placed in those regions, to enjoy the bounty and to adore the perfections of their great Creator. The double ring of Saturn, when viewed through a good telescope, generally appears like a luminous handle on each side of the planet, with a dark interval between the interior edge of the ring and the convex body of Saturn; which is owing to ils oblique position with respect to our line of vision. When its outer edge is turned directly lowards the earth, it becomes invisible, or appears like a dark stripe across the disk of the planet. This phenomenon happens once every fifteen years.
The planet Hertchel.—This planet, which is also known by the names of the Georgiurm Sidue, and Uranus, was discovered by Dr. Herschel on the ISth March, 1781. It is the, sanst distant planet from the sun, that has yet been discovered; being removed at no less than 1800 millions of jitlea from that luminary, which is nineteen t.mes farther than the earth is from the sun—a distance so great, that a cannon ball, flying at the rate of 480 miles an hour, would not reach it in 400 years. Its diameter is about 55,000 miles; and, of course, it is about eighty times larger than the earth. It appoars like a star of the sixth magnitude; but can seldom be distinguished by the naked eye. It takes about 83 years and a half to complete its revolution round the sun; and, though it is the slowest moving body in the system, it moves at the rate of 15,000 miles an hour. As the degree of sensible heat in any planet does not appear to depend altogether on its nearness to the sun, the temperature of this planet may be as mild as that which obtains in the most genial climate of our globe.* The diameter of the sun, as seen from Herschel, is little more than the apparent diameter of Venus, as seen by the naked eye; and the light which it receives from that luminary, is 360 times less than what we experience; yet this proportion is (bund by calculation to be equal to the effect which would be produced by 248 of our full moons; and, in the absence of the sun, there are sist moon* which reflect light upon this distant planet, all of which were discovered likewise by Dr. Herschel. Small as the proportion of light is, which this planet receives from the sun, it is easy to conceive, that beings similar to man, placed on the surface of this globe, with a slight modification of their organs of vision, might be made to perceive objects with a clearness and distinctness even superior to what we can do. We have only to suppose, that the Creator has formed theireyes with pupils capable of a much larger expansion than ours; and has endued their retina with a much greater degree of nerruus sensihility. At alt events, we may rest assured, that He who has placed sentient beings in any region, has, by laws with which we are partly unacquainted, adapted the constitution of the inhahitant to the nature of the hahitation.
■ Strange and amazing must the difference be, "Twtxt this dull planet and bright Mercury; Vet reason says, nor can we doubt at all. Millions of beings dwell on either ball, with constitutions fitted forthat spot Where Providence, all-wise, has fixed thelrlot."
The celestial globes which I have now described, are all the planets which are at present known to belong to the solar system. It is probable that other planetary bodies may yet be discovered between the orhits of Saturn and Herschel, and even far beyond the orhit of tho latter; anJ it is also not improbable that planets may
"See Note, page 83.
exist in the immense interval of 37 millions of miles between Mercury and the Sun.f These (if any exist) can be detected only by a series of day observations, made with equatorial telescopes; as they could not be supposed to be seen, after sunset, on account of their proximity to the sun. Five primary^, planets, and eight $econdane$t have been discovered within the last 42 years , and, therefore, we have no reason to conclude, that all the bodies belonging to our system have yet been detected, till every region of the heavens be more fully explored.
Comets.—Besides the planetary globes lo which I have now adverted, there is a class of celestial bodies which occasionally appear in the heavens, to which the name of comets has been given. They are distinguished from the other celestial bodies, by their ruddy appearance, and by a long train of light, called the tail, which sometimes extends over a considerable portion of the heavens, and which is so transparent, that the stars may be seen through it. The tail is always directed to that part of the neavens which is opposite to the sun, and increases in size as it approaches him, and is again gradually diminished, as the comet flies off to the m1re distant regions of space. Their apparent magnitude is very different: sometimes they appear only of the higness of the fixed stars; at other times they equal the diameter of Venus; and sometimes they have appeared nearly as large as the moon. They traverse the neavens in all directions, and cross the orhits of the planets. When examined through a telescope, they appear to consist of a dark central nucleus, surrounded by a dense atmosphere, or mass of vapours. They have been ascertained to move in long narrow ellipses or ovals, around the sun; some of them, on their nearest approach to him, having been within a million of miles of his centre ; and then fly off to a region several thousands of millions of miles distant. When near the sun, they move with amazing velocity. The velocity of the comet which appeared in 1680, according to Sir Isaac Newton's calculation, was eight hundred and eighty thousand miles an hour. They appear to be bodies of no great density, and their
* The Author, some years ago, described a method by which the planets flf any) within the orbit of Mercury, may he discovered In the day-time, by means of a simple contrivance for Intercepting the solar rays, and by the frequent application, by a numberof observers,of powerful telescopes, to a certain portion of the sky. In the vicinity of the sun. The details of this plan have not yet been published; but the reader will see them alluded to in No. V. of the Edinburgh Philosophical Journal, for July 1890, p. lsl.
I A primary planet Is that which revolves roui.d the sun as a centre; as Mara, Jupiter, and Saturn. A secondary planet Is one which revolves round a primary planet as its centre; as the Moon, and the satellites of Jupiter and Saturn. The primary planets are distinguished from the fixed stars by the steadiness of their light; not having a ticinixing appearance, as the stars exhibtt.
siza seldom exceeds that of the moon. The length of the tails of some comets has been estimated at fifty millions of miles. According to Dr. Herschel's computations, the solid nucleus or central part of the comet which appeared in 1811, was only 428 miles in diameter ; but the real diameter of the head, or nebulous portion of the comet, he computed to be about 127 thousand miles. The length of its tail he computed to be above one hundred millions of miles, and its breadth nearly fifteen millions. It was nearest to the earth on the 11th of October, when its distance was 113 millions of miles. The number of comets which have occasionally been seen within the limits of our system, since the commencement of the Christian era, is about 500, of which the paths or orhits of 98 have been calculated.
As these bodies cross the paths of the planets in every direction, there is a possihility, that some of them might strike against the earth in their approach to the sun; and, were this to happen, the consequences would be awful beyond description. But we may rest assured that that Almighty Being who at first launched them into existence, directs all their motions, however complicated ; and that the earth shall remain secure against all such concussions from celestial agents, till the purposes of his moral government in this world shall be fully accomplished. What regions these bodies visit, when they pass beyond the limits of our view; upon what errands they are sent, when they again revisit the central parts of our system; what is the difference in their physical constitution, from that of the sun and planets; and what important ends they are destined to accomplish, in the economy of the universe, are inquiries which naturally arise in the mind, but which surpass the limited powers of the human understanding at present to determine. Of this, however, we may rest assured, that they were not created in vain; that they subserve purposes worthy of the infinite Creator; and that wherever he has exerted his power, there also he manifests his wisdom and beneficence.*
Such is a general outline of the leading facts connected with that system of which we form a part. Though the energies of divine power had never been exerted beyond the limits of this system, it would remain an etemal monument of the wisdom and omnipotence of its Author. Inde
■ A comet has lately been discovered, whose perl'" odlcal revolution Is found to be only a years and 107 days. At Its greatest distance from the sun, It Is within the orbtt of Jupiter, and It possesses this peculiar advantage for observation, that U will become visible ten times in thirty-three years. It was last seen In June, 1893, by the astronomers in the observatory of Paramatta, New Holland, in positions very near to those which had been previously calculated by Mr Enke. It is probable, that the observations which may hereafter be made on this comet, wtU lead, to more definite and accurate views of the nature anJ destination of these singular bodies.
pendent of the sun, which is like a vast uni versa in itself, and of the numerous comets which are continually traversing its distant regions, it contains a mass of material existence, arranged in the most beautiful order, two thousand five hundred limes larger than our globe. Prom late observations, there is the strongest reason to conclude, that the sun, along with all this vast assemblage of bodies, is carried through the regions of the universe, towards some distant point of space, or around some wide circumference, at the rate of more than sixty thousand miles an hour; and if so, it is highly probable, if not absolutely certain, that we shall never again occupy that portion of absolute space, through which we are this moment passing, during all the succeeding ages of eternity.
Such a glorious system must have been brought into existence, to subserve purposes worthy of the infinite wisdom and benevolence of the Creator. To suppose that the distant globes, of which it is composed, with thtir magnificent apparatus of rings and moons, were created merely for the purpose of affording a few astronomers, in these latter times, a peep at them through their glasses, would be inconsistent with every principle of reason; and would be charging Him, who is the source of wisdom, with conduct which we would pronounce to be fully in the sons of men. Since it appears, so far as our observation extends, that matter exist! solely for the sake of sensitive and intelligent beings, and that the Creator made nothing in vain; it is a conclusion to which we are necessarily led, that the planetary globes are inhahited by various orders of intellectual brings, who participate in the bounty, and celebrate the glory o. their Creator.
When this idea is taken into consideration, it gives a striking emphasis to such sublime declarations of the sacred volume as these:—''Ail nations before him are as nothing—He sitteth upon the circle of the earth, and the inhahitants thereof are as grasshoppers—The nations are as the drop of a bucket—All the inhahitants of the world are reputed as nothing in his sight; ard he doth according to his wilt in the army of heaven, and among the inhahitants of the earth—Thou hast made heaven, and the heaven of heavens, with all their host; and thou preservest them all, and the host of heaven worshippcth thee—When I consider thy heavens, what is man, that thou art mindful of him!" If the race of Adam were the principal intelligences in the universe of God, such passages would be stripped of all their sublimity, would degenerate into mere hyperboles, and be almost without meaning. If man were the only rational being who inhahited the maUrial world, as some arrogantly imagine, it would be no wonder at all, that God should be " mindful of him;" nor could "all the inhahitants of this world," with any propriety, be compared to * a drop of a bucket," and be "reputed ai nothing in his sight.'* Such declarations would be contrary to fact, if this supposition were adm it ltd ; for it assumes that man holds the principal sbilion ir. the visible universe. The expressions—"The heavens, the heaven of heavens," and "the host of heaven worshipping God," would also, on this supposition, degenerate into something approaching to mere inanity. These expressions, if they signify any thing that is worthy of an inspired teacher to communicate, evidently imply, that the universe is vast and extensive, beyond the range of human comprehension* —that it is peopled with myriads of inhabitants —that these inhabitants are possessed of intellectual natures, capable of apprecialing the perfections of their Creator—and that they pay him a tribute of rational adoration. "The host of heaven worshippeth thee." So that the language of scripture is not only consistent with the doctrine of a plurality of worlds, but evidently supposes their existence to all the extent to which modern science can carry us« However vast the universe now appears—however numerous the worlds and systems of worlds, which may exist within Us boundless range—ihe language of scripture is sufficiently comprehensive and sublime, to express all the emotions which naturally arise in the mind, when contemplating its structure—a characteristic which will apply to no other book, or pretended revelation. And this consideration shows not only the harmony which subsists between the discoveries of revelation and the discoveries of science, but also forms by itself a strong presumptive evidence, that the records of the Bible arc authentic and divine.* Vast as the solar system, we have now been contemplating, may appear, it is but a mere point in the map of creation. To a spectator placed in one of the stars of tho seventh magnitude, not only the glories of this world, and the more resplendent scenes of the planet Saturn, but even the sun himself would entirely disappear, as if he were blotted out of existence. "Were the sun," says Mr. Addison, "which enlightens this part of the creation, with all the host of ihe planetary worlds that move about him, utterly extinguished and annihilated, they would not be missed by an eye that could take in the whole compass of nature, more than a grain of sand upon the seashore. The space they possess is so exceedingly little, in comparison of the whole, that it would scarce make a blank in creation."
The Fixed Start.—When we pass from the planetary system to other regions of creation, we have to traverse, in imagination, a space so immense, that it has hitherto baffled alt tho efforts of science to determine its extent. In these remote and immeasurable spaces, are placed
See Appendix, No TL
those immense luminous bodies usually denominated timjixed star*. The nearest stars are, on good grounds, concluded to be at least twenty billions of miles distant from our globe—a distance through which tight (the swiftest body in nature) could not travel in the space of three years; and which a ball, moving at the rate of 500 miles an hour, would not traverse in four millions fivs hundred thousand years, or 750 times the period which has elapsed since the Mosaic creation.— But how far they may be placed beyond this distance, no astronomer will pretend to determine. The following consideration will prove, to those unacquainted with the mathematical principles of astronomy, that the stars are placed at an immeasurable distance. When they are viewed through a telescope which magnifies objects a thousand times, they appear no larger than to the naked eye; which circumstance shows, that though we were placed at the thousandth part of the distance from them at which we now are, they would still appear only as so many shining points; for we should still be distant from the nearest of them, twenty thousand millions of miles: or, in other words, were we transported several thousands of millions of miles from the spot we now occupy, though their numbers would appear exceedingly increased, they would appear nc 'aiger than they do from our present station; am* ve behooved to be carried forward thousands of millions of miles further in a long succession, before their disks appeared to expand into large circles, like the moon. Dr. Herschel viewed the stars with telescopes, magnifying six thousand times, yet they still appeared only as brilliant points, without any sensible disks, or increase of diameter. This circumstance incontestably proves the two following things :—
1. That the stars are luminous bodies, which shine by their own native light; otherwise they could not be perceived at such vast distances.
2. That they are bodies of an immense size, not inferior to the sun; and many of them, it is probable, far exceed that luminary in bulk and splendour.
The stars, on account of the difference in their apparent magnitudes, have been distributed into several classes or orders. Those which appear largest are called stars of the Jtrst magnitude; next to those in lustre, stars of the second magnitude, and so on to stars of the sixth magnitude, which are the smallest that can be distinguished by the naked eye. Stars of the 7th, 8th, 9th, 10th, &c. magnitudes, which cannot be seen by the naked eye, are distinguished by tho name of telescopic stars. Not more than a thousand stars can be distinguished by tho naked eye, in the clearest winter's night; but, by means of the telescope, millions have been discovered. (See p. 11.) And, as it is probable that by far the greater part lie beyond the reach of the best glasses which have been or ever will be constructed bv man—