the breadth of a silver-wire, the splendour is surprising. In size he is so great, that the whole mass of matter in all the planets is not tro part of that contained in the sun ; and the luminous matter that surrounds him is of still greater surface than himself. So intense is the light that we perceive, it is suficient to render the planets visible to us, some of them very brilliant, and also to illumine the moons of that one which is farthest from the centre. Now, though some votary of chance might contend, that the planets had arranged themselves at their respective distances, and that this accidental arrangement first gave birth to the present system, which would not otherwise have existed, yet he cannot possibly do honour to his reason and at the same time affirm, that this supposed accidental arrangement also occasioned the appropriate inclination of their axes, produced their moons in the requisite allotment, adapted these moons by a proper libration to the purpose of satellites, adjusted their revolutions, rendered the sun luminous, and gave it the needful intensity of light. Of these facts there is no explanation, but upon the principle of contemplated relations, and the Forecast of an intelligent Being The arrangement of such a vast system as the universe, required, moreover, many provisions against the interference and perturbation of its parts, and many counteractions of such perturbation where it could not be avoided without sacrificing a greater good, or marring the symmetry of the whole. In our system alone, we may just mention the influence of the planets on each other, and on the sun,-the consequent perturbation of their elliptic motions,-the inequality of the moon, and of the satellites of Jupiter,—the action of the sun and moon on the earth producing a slow motion on its poles around the poles of the ecliptic,—the influence of gravity on the ocean, the paths of comets in their courses ;-how were all these, and many other difficulties in such a complicated system under the power of one great law, to be so adjusted as to prevent the early or later derangement and dissolution of the whole ? According to La Place, “ the perturbations of the elliptic motion of the planets may be divided into two classes, not essentially different, the secular inequalities which increase with extreme slowness, and the periodic inequalities which depend on the configurations of the planets, both with respect to each other and to their nodes and perihelia. The latter, according to their name, are re-established every time these configurations become the same, that is, at intervals not very long. But the G former are found to be equally periodic, though their periods are much longer, as they develope themselves only in the course of ages." So that, on this head, the mean motions of these bodies and their distances from the sun are invariable; the system is so constructed as to preserve its form, rectifying itself at certain calculable periods, and these rectifications are a part of the constituted order of things. La Place supposes the following questions may occur to the mind : “ Have the planetary ellipses always been, and will they always be, nearly circular? Among the number of planets have any of them ever been comets, whose orbits have gradually approached to the circular form by the mutual attraction of the other planets ? Will the obliquity of the ecliptic continually diminish, till at length it coincides with the equator, and the days and nights become equal on the earth throughout the year ?" Analysis answers these questions in the most satisfactory manner. “I have (he says) succeeded in demonstrating, that whatever be the masses of the planets, inasmuch as they all move in the same direction, in orbits of small eccentricity, and little inclined to each other, their secular inequalities will be periodic, and even contained within narrow limits ; so that the planetary system will only oscillate about a mean state, from which indeed it will deviate but a very small quantity. The planetary ellipses, therefore, have always been and always will be nearly circular ; from whence it follows that no planet ever has been a comet, at least if we only calculate upon the mutual actions of the planetary system. The ecliptic will never coincide with the equator, and the whole extent of its variations will never exceed 2, 42." The vast number of comets indicates that they are necessary for some purpose or purposes in the general economy of nature ; as yet, however, their use is unknown. Estimating their density by the force of their attraction, which is but small, and considering the vast distances to which they stretch away beyond the genial influence of the sun, we may conclude they are not habitable bodies. They have no rotation like the planets, . and though they retire to a great distance from the source of light, are not attended with moons. The want cannot be said compensated by their near approach to the fixed stars, for this is disproved by their periodical returns. The absence of moons, their want of rotation, and particularly their number, all certify that they are a distinct class of bodies, and not planets, whose course has been deranged. Since they were to exist, provision has been made against their interfering with other to be а parts of the system. The great eccentricity of their orbits makes them liable to be disturbed by the attraction of the planets; but in order to avoid this as far as might be proper for the long duration of the system, the planets revolve nearly in the same pláne, while the comets are dispersed all over the heavens, stretch away to such distances as render their visitations very occasional, and afford an opportunity of so diversifying their periods of return, that a number shall not be passing at once to the sun. They move slowest when farthest from the sun, and pass so rapidly when near any of the planets, or in the region that might most affect them, that the effect of their attraction is not to be feared. Actual collision alone is to be dreaded, and this, though possible, is exceedingly improbable even for a long course of agés.* “ The acceleration of the mean motion of the moon, which was supposed to augment continually, is found to be a secular equation of a very long period, which compensates itself in the course of ages, alternately increasing from nothing to its maximum, and diminishing to nothing again.” The acceleration of the moon seemed to argue a constant diminution of her distance from the earth, and gave countenance to the idea that the planetary orbits were diminishing, and that there was a tendency among all the bodies of our system to descend to the centre of gravity, where their union must terminate the present order of nature,—a catastrophe sung by Darwin ;t but the destiny of nature is more sublime. Whatever be its duration, imperfection in its mechanism will not be its ruin. Certain perturbations take place among the satellites of the primary planets, from their necessary action upon one another. These have been investigated in the case of Jupiter's satellites, a • It was feared the comet of 1744 would disturb the planet Mercury; but it was found that wben nearest the planet it was twice as near the sun. So no disaster ensued.-See EDINBURGH Review of La Place's System of the World, wbich the author bad not the opportunity of studying otherwise. Yet La Place is said to have continued a sceptic ! + Roll on, YE STARS! exult in youthful prime, Mark with bright curves the printless steps of time; Bot. Gar. vol. i. cant. iv. I. 379. as affording the best facilities ; and they are found to be a system of bodies connected by remarkable relations and inequalities, which their mutual action would maintain for ever, if left to itself. This action also changes every moment the position of their orbits, so that the nodes of these orbits have retrograde motions whose periods are all determined. * Though we know not the use of Saturn's Ring so as to be able to point out ulterior design, yet no less than seven independent circumstances were requisite to its existing as it is, without being displaced ; all these we observe, and they afford a cogent proof of design in its structure. In particular, La Place has demonstrated that there is an irregularity in the form of the ring, and that this irregularity of a certain magnitude, neither too great nor too small, was absolutely necessary to prevent the ring from falling down on the planet.t Not to protract the enumeration, we only notice, that the shape of the earth as an oblate spheroid, formerly remarked as an arbitrary conformation, tends to prevent the ocean from overflowing the land. It would otherwise rise, till the increase of depth made up for the diminution of its gravity within the tropics by the centrifugal force. La Place has shewn farther, that the motion communicated to the mass of water which surrounds our globe by the action of the sun and moon, will never increase to any undue elevation of the ocean, because the undulation of the waters continually tends to diminish from their gravitation to the earth ; and that thus the equilibrium of the sea will be stable,- it will not rise nor will it subside, so long as the density of its waters is below the mean density of the earth. III.—Were we now to descend from this survey of the universe, and planetary system, to the economy of Nature around us, what new and admirable arrangements would rise into view, all equally directed to the preservation of diversified yet harmonious co-existence. One meets the necessities generated hy another, and those again, to which the former gives birth, are so appropriately met by other arrangements, that the circle of perfection is traced without either Haw or unseemly deviation. The classes of beings, animate or inanimate, are not too numerous, yet sufficiently varied to constitute the several kingdoms of nature ; none of them are, like pure spirits, unfitted See EDINBURGH ENCYCL. Astronomy. + Eclectic Review of Connaissance de Tems for 1811. Sept. 1810. for connexion with the earth, yet they terminate in an order of intelligent beings capable of presiding over the rest,-beings in whom matter and spirit are conjoined, attached by their bodies to the terrestrial fabric, by their spirits fitted for recognising and serving a Deity. While the characteristic distinctions are preserved, the several classes are connected by intermediate links, through which the gradations of life and diversified existence may be traced. Then, what a wonderful scheme of dependencies, reciprocations, provisionary processes, and subservient interests, pervades and unites the whole, without blending the several departments. The chemical powers, the vegetative vis, the rational and moral faculties, have all their province; and where the end could not be gained, either with propriety or with sufficiently certain effect, by any of these, the department of instincts fills up the chasm. In the ordinary processes of nature, there are many laws which, though they continue to operate steadily at all times, are yet necessarily influenced and modified by various circumstances, which sometimes augment, sometimes diminish their action, and not unfrequently give it a new direction ; and no small part of that beautiful economy of nature, which either presses itself on our notice, or surprises the intelligent inquirer in almost every discovery he makes, arises just from the harmonizing effects of these reciprocations. And now, is there no evidence of fore-thought in the structure and arrangements of a system so multiform and complex, yet so perfectly consistent, a system from which apparent perplexities constantly vanish, just in proportion to its developement by the progress of science,-a system so admirably fitted for exhibiting in strong characters the diversities of possible existence, and combining them in every relation of utility without the smallest confusion ? Was there no prior conception of the sum total to be formed ? No contemplation of necessities and expedients ? No calculation of the results of general laws in different dispositions of their subjects, and of the ways and means by which perturbation might be avoided, harinony produced, and the preservation of the whole ensured ? No such forecast as must prove an Intelligent First Cause, and at the same time be understood in a manner worthy of the Deity ? Let Reason assume her place,—and surveying all the proofs of Volition, Design, and Contrivance, with which the universe |