so large a globe as the Moon, upwards of two thousand miles in diameter, could answer no other purpose than that of a flickering lamp, which ceased to burn during the greater number of our darkest nights, and which, when it did burn, was so often eclipsed by the clouds and vapours of our atmosphere. Philosophers of high caste did not hesitate to conclude that the Moon must be a world like the Earth, with its mountains, and rocks, and plains, and valleys, fitted for the reception of, or already occupied by, animal and intellectual races like our own. In the Divine economy, creative power has never been found to have been exerted in vain, and when we see huge inorganic masses of matter like the Moon, shaped like our own sphere, and chiselled into the various forms of a world fit to be inhabited, we instinctively infer the existence of organic and intellectual life as the principal object of their creation.

In the progress of astronomical discovery new arguments for worlds beyond our own were rapidly accumulated. When the truth of the Copernican system was demonstrated, and six primary and many secondary planets or moons took their ordained places in the heavens, the evidence for a plurality of worlds became irresistible, and minds of all degrees of capacity, and of every shade of feeling, received and confided in so cheering a truth, as one next in certainty to that of the astronomical facts on which it rested. Occupying a place in the planetary system, and possessing no peculiar advantages, our Earth lost its position of dignity as the only world in creation, and, contrasted with Jupiter, enlightened with four moons, and Saturn with six, the one planet being ten, and the other nine times larger than our own, it dwindled into a world of the third degree, great indeed in its littleness, but yet shorn of its grandeur. In examining more carefully these rival worlds, we find in them so many common functions, that we cannot escape from the conclusion that they were created for a common purpose. Lighted by the same beams, and heated by the same radiations,-shaped in the same oblate mould,-surrounded with atmospheres-enjoying day and night and difference of seasons, can we doubt that they were intended for the residence of beings intellectual and immortal like ourselves? When we see the moons of Jupiter and Saturn eclipsing the sun, and themselves suffering an eclipse in the shadow of the planet, we identify these worlds more strikingly with our own; but when we regard these moons in their higher function of affording a more continued light to their planets than we receive from our own, we cannot conceive any adequate object for their creation but that of guiding the wayfarer in the night, and throwing upon the distant planet a more abundant reflection of the solar rays. In such palaces as these, so lofty

Proofs of a Plurality of Worlds.

3

and magnificent, so nobly furnished, so warmed and so lighted up,-is there no living soul to kneel in gratitude to the Architect who made them? Is there no sovereign to hold his court in their halls, and to sway the sceptre over their boundless empires? Is there no animal life to browse upon their green savannas,— no shaggy autocrat in their forests, no bulky leviathan in their oceans,—no condor in their atmospheres,-to illustrate the variety of creative power? Is there no sage there to unfold the mysterious phenomena which their earth and their heavens must display, no sympathetic hearts to rehearse in their bowers and their glades those impulses of friendship and of love which are to revive and become permanent in their future being? To these interrogations the philosopher and the Christian must make the same reply. Reason and faith must on this occasion, if they unfortunately diverge in others, join in the same anthem of gratitude and of praise.

When we survey the other planets, nearer in locality to our own, though not furnished with moons to give them light in the sun's absence, we meet with the same instructive analogies, and are led to the same conclusion, that they are habitable worlds. Venus, of nearly the same size with our Earth, and Mars and Mercury of about half its magnitude, have their days of almost exactly the same length as our own." In Mars its atmosphere is most conspicuous, and astronomers have observed what they regard as snow in its polar regions, and green savannas in its equatorial plains; but owing to its never being gibbous like the moon and the two inferior planets, the mountains which it undoubtedly possesses cannot be discovered by the telescope. In Venus and Mercury astronomers have observed that diversity of surface which appears in our own Earth and Mars, and in all the other planets an atmosphere which is very distinct in Venus, and in Venus and Mercury lofty mountains, which they have measured. Owing to their proximity to the Sun, however, and the consequent brilliancy of their discs, it is very difficult to study their physical structure, and from the same cause it is even possible that they may be attended with small moons which have hitherto escaped the cognizance of our telescopes. But, independently of this point of analogy with our Earth, their resemblances in physical character, and in their daily and annual movements,

It is a curious fact which has not been noticed, that the mean of the days in Mars, Venus, and Mercury, are within less than a minute of 24 hours, the length of our own day; and the mean of the days of Jupiter, Saturn, and Uranus, are nearly coincident with 9 h. 56 m., the length of Jupiter's day. The days of Mercury, Venus, the Earth, and Mars, are respectively 24 h. 5 m. ; 23 h. 21 m.; 24 h.; 24 h., 37 m., the mean of which is 24 h. 0 m. 45 s. The days of Jupiter, Saturn, and Uranus, are respectively 9 h. 56 m., 10 h. 29 m., 9 h. 30 m., the mean of which is 9 h. 38 m.

authorize us to conclude, that such globes of matter, warmed and lighted more effectually than our own, are still better adapted for the residence of vegetable, animal, and intellectual life.

It is hardly necessary to conduct our readers to the remoter planets of the solar system, and to advert to the ring of Saturn, and the satellites of Uranus, and of Neptune, as strengthening our position, that all the planets around us have been created to be the seats of life, and the abodes of intelligence. The opinion that the Earth only was inhabited, became more and more presumptuous in proportion as our system was enlarged, and every discovery of a new planet became a fresh argument for a plurality of worlds.

Before quitting the general argument derived from the similarity between the different bodies of our system, we must notice the remarkable opinion maintained by Sir William Herschel, that the Sun itself is inhabited. When we consider the immense nagnitude of the Sun, which is equal to all the planets put together, it was not an unreasonable supposition, that such an enormous mass of matter might afford a habitation for intellectual beings, while it performed its more obvious functions of lighting, heating, and guiding the other planets of the system. Sir William conceived that the light and heat of the great central body emanated from an outer stratum of phosphoric clouds, composing its luminous atmosphere, and that the dark and solid nucleus, which we often see through openings in this atmosphere, is protected from the fiery blaze by another stratum of opaque and non-conducting clouds. That a temperate, or even a tropical climate, could be obtained by any screen of clouds, it would be difficult to conceive, but as beings may be created capable of enduring any degree of heat, we have no right to consider the probable temperature of the Sun as a proof that it cannot be inhabited. For the same reason Sir William Herschel might have repelled the objection of Dr. Young, that upon the Sun the weight of a man of moderate size would be above two tons. There are certainly no grounds of analogy upon which we can support this theory, and we have adduced it only to shew how strong must have been his faith in the doctrine of the plurality of worlds, who maintained that the Sun is the seat of life and intelligence.

In order to corroborate the preceding views, it is necessary to remove some difficulties that have been felt by those who confide in them, and reply to some objections that have been urged by the few that oppose them. All these difficulties and objections are founded on the assumption, that the inhabitants of the planets must be of the same size, and the same physical conformation as man; and, were this admitted, it would justify the

Inhabitants like Man might live on the Planets.

5

conclusion, that such creatures could not rightly perform their functions in the remote planets, where the light and heat of the sun are so greatly reduced by their distance, as to be incapable of sustaining the animal and vegetable life which exists on the earth. In like manner, the inhabitants of Venus and Mercury, if they have eyes and nerves like ours, could not possibly endure that brilliancy of light and intensity of heat which these planets receive from the sun. Now, there are two answers which may be given to these objections. The cold which we presume exists in the remote planets, and the heat which is supposed to exist in the inferior ones, may be tempered by certain atmospherical conditions of which we have examples in our own earth, or by some other arrangement which we cannot divine. But independent of this supposition, the human eye could easily endure the light upon Mercury and Venus, by means of a small pupil, and a less sensitive retina, while in the remote planets an enlarged pupil, and a sensitive retina, would enable an eye like our own to see objects as brightly as they do at present. In like manner, the nervous system which receives the impressions of heat and cold, could be easily adjusted to bear the highest heat and the severest cold.

The shortness of the day in the remote planets-that period which measures our intervals of rest and labour, has been urged as an objection to the plurality of worlds. It is an objection, however, without any force. Even man, without any change in his physical conformation, could live and thrive with five hours of activity, and other five of repose. In our own arctic regions, where the diurnal motion of the earth marks no such intervals, the inhabitants of the temperate zone can perform their functions as well as in southern climates.

As the strength of the human frame must be accommodated to its weight, and as its weight, as well as that of all other bodies, depends upon the force of gravity at the surface of the planet, it has been alleged that human beings could not exist on such planets as Jupiter and Saturn, whose mass or quantity of matter is so much greater than that of our earth. This objection, as we have already seen, is a very formidable one, in reference to the Sun, where a man would weigh two tons; but it loses all its force when we make an accurate calculation of the force of gravity, and of the weight of a human body, on the largest of the planets. In the case of Jupiter, for example, its size or volume is 1330 times that of the earth, and if both planets consisted of the same kind of matter, a man weighing 150 lbs. on the surface of the earth would weigh 150 x 1330 or 199,500 lbs. at a distance from Jupiter's centre equal to the earth's radius; but if the man stood on Jupiter's surface, whose radius is eleven times greater than that of the earth, his weight would be diminished in the ratio of

the square of their radii, that is, in the ratio of 11 x 11 or 121 to 1. Hence, if we divide 199,500 lbs. by 121, we shall have 1649 lbs. as the weight of the man on the surface of Jupiter, or eleven times heavier than he is here. But the materials which compose Jupiter are much lighter than those of which our earth consists, and consequently, the quantity of attracting_matter is much less than we have supposed. The density of Jupiter is to the density of the earth in the ratio of 24 to 100, or less than four to one, so that by dividing 1649 lbs. by 4, we have 412 lbs. as the weight of a man on Jupiter, who weighs here only 150 lbs., that is, only 24ths greater, a difference which actually exists between many individuals in our own planet. If we make the same calculation for Saturn, Uranus, and Neptune, we shall find that in Saturn the weight of a man is very little greater than on our earth, and that in Uranus and Neptune, it is a very little less;* so that beings of the same physical constitution as ourselves could exist without inconvenience on all the remote planets; and plants, and trees, and buildings, such as those which occur on our earth, could grow and stand secure, in so far as the force of gravity is concerned.

In replying to objections such as those we have been considering, we have perhaps conceded too much to the limited views of the persons who made them. To assume that the beings who occupy a plurality of worlds, are, necessarily, to be either men or anything resembling them, is to have a low opinion of that infinite skill which has produced such a variety in the form and structure and functions of vegetable and animal life. In the various races of man which occupy our globe, there is not the same variety which is exhibited in the brutes that perish. Although the noble Anglo-Saxon stands in striking contrast with the Negro or the Islander of the Pacific, and the lofty Patagonian with the diminutive Esquimaux, yet in their general form and functions and composition they are essentially the same. But when we look into the world of instinct, and survey the infinitely varied forms which people the earth, the ocean, and the air;—when we range with the naturalist's eye from the elephant to the worm-from the leviathan to the infusoria-and from the eagle to the ephemeron, what beauty of form-what diversity of functionwhat variety of purpose is exhibited to our view! In all these forms of being, reason might have been given in place of instinct, and animals the most hostile to man, and the most alien to his habits, might have been his friend and his auxiliary, in place of

* We have taken the preceding numbers from a very interesting article in Dr. Lardner's Museum of Science and Art, one of the few works of the kind which can be recommended as at once popular and accurate.