to the syzygies, but retards it from the syzygies to the quadratures. This inequality is called the Variation, it disappears at the syzygies and quadratures, and is greatest half way between them.

The orbit of the earth itself being an ellipsis, the sun's attractive force is greatest at the perigee, and least in its apogee; hence arise changes in all the foregoing equations, which constitute an irregularity, whose period is a year, and which is hence called the Annual equation.

The axis of the moon's orbit, that of the earth's orbit, and the line of the moon's nodes, are constantly changing their relative positions; hence arises an inequality, whose period is eight hundred and twenty-five years.

The eccentricity of the earth's orbit is changing at a slow rate; from this it arises that the velocity of the moon is constantly increasing, and her periodic time diminishing. These equations have a period of many thousands of years. That which affects the lunar motion, was formerly called the Acceleration, but has, since its cause has been discovered, been named the Secular equation.

The orbit of the moon is inclined to the ecliptic, and hence arises a motion in the nodes of this orbit, which is due to the action of that part of the sun's disturbing force which is exerted in the direction of the line that joins the centres of the earth and sun. This motion, taken at a mean rate, is retrograde, but in consequence of the variation in the position of the moon in its orbit, the actual motion is oscillating, sometimes in the order of the signs, sometimes retrograde; but the latter is in excess; whence the mean retrograde motion. This amounts to about 19° 18' in a sidereal year.

The same cause produced a variation in the inclination of the moon's orbit. This is also oscillating, and confined within very narrow limits. The diminution of the gravitation of the moon towards the earth, by the action of the sun, produces a motion of the sine of the apsides. For, in consequence of this, the path of the moon will fall between the original ellipsis and the tangent to the orbit, and will not intersect the radius vector at right angles a second time, until the moon has passed through an arc of more than 180°. This motion, referred to the apogee, is that which, as has been stated, led Clairaut to suspect a change in the law of gravitation; but which was finally found to correspond with it.

At the present moment, the tables of the moon's motion contain twenty-eight equations for the longitude, twelve for the latitude, and thirteen for the distance of the moon from the earth. And the greatest probable error of position, does not amount to more than a few seconds. Hence arises one of the most import

ant practical applications of astronomy, to the determination of longitudes at sea, by the distance of the moon from fixed stars or the sun.

The system of Jupiter and his satellites, is a miniature of the great system of sun and planets: here again, therefore, we find, first the general laws of Kepler, viz., motion in plane curves; the spaces described by the radius vector proportioned to the times; and the squares of the periodic times proportioned to the cubes of the greater axes. We next find them affecting each other's motions by their mutual actions, and the eccentricities and lines of their apsides changing under the action of the sun. The detail of these motions comprises some very remarkable phenomena :

There is a relation between the motions of the first three satellites, which is as follows, viz. The sum of the mean motion of the first, added to twice the mean motion of the third, is equal to three times the mean motion of the second:

The orbit of the first satellite is nearly circular, and has no sensible ellipticity, except what is communicated by the motion of the third and fourth. There is an inequality, which is principally produced by the motion of the second, which has a period of four hundred and thirty-seven days:

The position of the planes of the several orbits, may be defined by assuming five planes; of which the first is nearly fixed, and lies between the planes of the orbit and the equator of Jupiter, passing through their intersection, and preserving nearly a constant inclination; the second moves upon the first, making with it a constant angle; the third upon the second, the fourth upon the third, and the fifth upon the fourth, each at constant angles. The fifth plane is that of the orbit of the satellite.

These first planes are different for each satellite, being less inclined, as its distance from the planet is less; and this grows out of the accumulation of matter at the equatorial regions of Jupiter.

The nodes of the second satellite make a revolution in about thirty years; those of the third in about one hundred and forty-two, and those of the fourth in five hundred and thirty-one years.

The orbit of the second satellite, has, like the first, but little eccentricity, but what arises from the action of the third and fourth. That of the third is visibly eccentric, and has two equations of the centre; the one arising from its own eccentricity, the other a variation produced by the eccentricity of the fourth satellite. The orbit of the fourth satellite has a greater eccentricity than that of any of the others. The line of the apsides of both of these is evidently in motion.

The satellites of Jupiter were among the earliest of the ap

pearances unfolded to astronomers, on the discovery of the telescope. Galileo saw them immediately after he first constructed his instrument, and was enabled to determine their distances from the planet, and the times of their revolutions. The inequalities of their motions were determined from observations of their eclipses, by the shadow of Jupiter. The first remarked was in appearance only. Roemer ascertained, that eclipses of the first satellite were in advance of their mean rate, when the planet was in opposition, and fell behind it near the conjunctions. He explained this, by the difference of the times that the light of the satellite takes to reach the spectator, in consequence of the difference in the distance of Jupiter, at these two periods, being equal to the diameter of the earth's orbit.

The persons who have distinguished themselves in the investigation of the physical theory of the motions of these bodies, are, first Newton, and finally Laplace; between whom may be cited the names of Bradley, Wargentin, Lagrange, and Bailly. From the formulæ of Laplace, have been constructed the tables now used in predicting their eclipses and oscillations; and the labour of calculating them was performed by Delambre.

The satellites of Saturn are seven in number. Their mean motions and distances are alone fully known; the five nearest to the planet have their orbits nearly in the plane of the ring; those of the sixth and seventh are considerably inclined to it, and are known to have elliptic orbits. The seventh has more obliquity than the sixth, and this is a natural consequence of the theory of gravitation; for the accumulation of matter around the equator of the planet, acts to draw their orbits into that plane, and also to keep near it the ring of the planet, while the sun acts to cause the inclination. It is only then in the more distant satellites that this last is sufficiently powerful to produce a marked inclination; and this result is observable, not only in the satellites of Saturn, but in those of Jupiter.

Herschell saw, by the aid of his powerful telescopes, six satellites accompanying the planet that goes by his name. No more than two of these have been seen by any other astronomer, which are, in the order of their distances, the second and fourth. These two follow the law of Kepler, the squares of the times of their revolutions being proportioned to the cubes of their distances. The planes of their orbits are perpendicular to the ecliptic, and hence may be inferred a rapid motion of the planet around an axis nearly parallel to that circle; here physical astronomy steps in to supply the defects of our vision, and to infer phenomena, which the most powerful instruments yet invented have failed to show us.

Such is a rapid outline of the system of the universe, and of the discoveries in relation to the explanation of it upon one ge

neral principle; investigations commenced by Newton and completed by Laplace. Of all the facts thus detected, various and important though they be, none is so remarkable as that which regards the permanency of the system, so far as the sun, the planets, and the satellites are concerned; and which analogy gives us a right to infer even in relation to the action of comets, however irregular and eccentric their motions may be. This permanency is then consonant with the great physical law of the indestructibility of matter. As we know of no physical agent that can annihilate the smallest and most unimportant particle, so also do we find no cause in action by which any diminution or permanent variation, in the motion of the heavenly bodies, can be detected.

If, however, we can trace no design in the mere constancy in the quantity of matter that makes up the universe, the stability of the solar system affords the most indubitable evidence of the action of vast power, and illimitable intelligence. This stability is by no means inherent in the physical nature of the bodies that compose the system, but grows out of their having been originally placed under certain peculiar circumstances. Thus, had not all the planetary orbits been nearly circular, had not they as well as their satellites moved in the same directions, and had there been any great obliquity among the orbits, however well arranged and regular might have been the system at first, a few revolutions would have involved the whole in inextricable confusion. Laplace has indeed attempted to transfer these conditions one step farther back, and to describe a state of distribution and motion, whence the simple action of gravitation might have deduced the present state of things, and the conditions of stability we have just given. He has, for this attempt, been accused of atheism, but certainly with no propriety; for, to proceed one step backwards towards the final cause of things, involves no denial of the omnipotence of that cause; nay, may in many cases lead to a more full exhibition of the wisdom with which the whole has been planned, and the power by which motions and properties, originally impressed upon inert and chaotic matter, have compelled it to assume a state, beautiful for its regularity, and admirable in its symmetry.

ART. II.-CORNEILLE.

1.-Euvres de Corneille, avec les notes de tous les Commentateurs. 12 vols. 8vo. Paris: chez Lefevre. 1824.

2.-Histoire de la Vie et des Ouvrages de P. Corneille. Par M. JULES TASCHEREAU. Paris: 1829.

WHILE pains have heretofore been taken by the literary journals of this country, to present a comprehensive view of the treasures of German, Italian, English literature,-to point out the excellence abounding in the dramatic compositions of these nations; while the greatest stress has often been laid in delineating even the minor features in the characters, and the most trifling incidents in the literary carcer of the poetical classics of England, Italy, and Germany, it is painful for us to confess, that comparatively little has been said of French writers of the same class, and, we believe, more especially of the dramatic compositions with which many of them have enriched the literature of their country. We cannot, at the present moment, revert to more than a very few articles in which the literary career of the first has been made a matter of primary consideration, or the latter a subject of fair critical examination.

The consequences of this are obvious. We have not unfrequently had occasion to observe, that, to many competent English scholars in these states, who have reaped from a diligent perusal of original works, and of our periodical reviews, a thorough acquaintance with all the beauties of Shakspeare,-with all the features of his extraordinary genius, as well as with those of English writers of very inferior note; who from the same periodical publications, have acquired a tolerable knowledge of even the details of the biography and literary career of German and Italian dramatic poets, the names, and still more evidently the dramatic works, of Corneille, Racine, Molière, and their successors, are hardly known; surely not as familiarly as the merited reputation they enjoy in their own country, and, indeed, all over the continent of Europe, so powerfully demands.

The second work, the title of which will be found at the head of this article, and which has not long since made its appearance, is the production of a gentleman already advantageously known to the literati of the European continent, by the history of the life and writings of Molière, published a few years since; and to the English reader, through the medium of a survey of the same work, contained in the third number of the Foreign