in astronomy, one of the planets of our solar system, revolving at the distance of more than 900 millions of miles from the sun. See Astronomy, p. 31, 104-109, 191, and 269.

Dr Herschel, who has so much signalized himself by his discoveries in the celestial regions, has not omitted to make his observations on this planet, which he considers as one of the most engaging objects that astronomy offers to our view. His attention was first drawn to it in the year 1774, when he saw its ring resembling in appearance a narrow line, extending on both sides not much less than the diameter of the planet's disk. The observation was taken with a five and an half feet reflector. The ring seems to be endowed with a greater reflective power than the body of the planet; and the Doctor gives instances of its being part of the ring brighter than Saturn himself, as well as of his seeing it plainly through a telescope which could scarcely afford light enough for the planet. The most remarkable property of this wonderful ring, however, is its extreme thinness. "When we were nearly in the plane of the ring (says our author), I have repeatedly seen the first, second, and third satellites, nay even the fifth and seventh, pass before and behind the ring in such a manner that they served as excellent micrometers to estimate its thickness. It may be proper to mention a few instances, especially as they will serve to solve some phenomena that have been remarked by other astronomers, though they have not been accounted for in a manner consistently with other known facts. July 18th 1789, at 19° 41' 9", sidereal time, the first satellite seemed to hang upon the following arm, declining a little towards the north, and I saw it gradually advance upon it towards the body of Saturn; but the ring was not so thick as the lucid point. July 23rd, at 19° 41' 8"; the second satellite was a very little preceding the ring; but the ring appeared to be less than half the thickness of the satellite. July 27th, at 20° 15' 12", the second satellite was about the middle, upon the following arm of the ring, and towards the south; and the sixth satellite on the farther end towards the north; but the arm was thinner than either of them. Aug. 29th, at 22° 12' 55", the third satellite was upon the ring, near the end of the preceding arm, when the latter seemed not to be the fourth, or at most the third part of the diameter of the satellite; which, in the situation it was, I took to be less than one single second in diameter. At the same time, I also saw the seventh satellite following the third, at a little distance, in the shape of a head upon a thread, projecting on both sides of the same arm. Hence also we are sure that the arm appeared thinner than the seventh satellite, which is considerably smaller than the fifth, which again is less than the first. August 31st, at 20° 48' 26", the preceding arm was loaded about the middle with the third satellite. October 15th, at 6° 43' 44", I saw the fifth satellite, without obstruction, about the middle of the preceding arm, though the ring was but barely visible with my 40 feet reflector, even while the planet was in the meridian. However, we were then a little inclined to the plane of the ring, and the third satellite, when it came near its conjunction with the first, was so situated, that it must have partly covered it a few minutes after I lost it behind my house. In all these observations, the ring did not in the least interfere with my view of the satellites. October 16th, I followed the fifth and seventh satellites up to the very disk of the planet; and the ring, which was extremely faint, did not in the least obstruct my seeing them gradually approach the disk, where the seventh vanished at 21° 46' 44", and the fifth at 22° 36' 44". There is, however, some suspicion, that by a refraction through some very rare atmosphere on the two planes of the ring, the satellites might be lifted up and depressed so as to become visible on both sides of the ring, even though the latter should be equal in thickness to the diameter of the smallest satellite, which may amount to 1000 miles.

As for the arguments of its incredible thinness, which some astronomers have brought from the short time of its being invisible when the earth passes through its plane, we cannot set much value upon them; for they must have supposed the edge of the ring, as they have also represented it in their figures, to be square; but there is the greatest reason to suppose it either spherical or spheroidal; in which case evidently the ring cannot disappear for any long time. Nay, I may venture to say, that the ring cannot possibly disappear, on account of its thinness; since, either from the edge or the sides, even if it were square on the corners, it must always expose to our sight some part which is illuminated by the rays of the sun; and that this is plainly the case we may conclude from its being visible in my telescope during the time when others of less light had lost it; and when evidently we were turned towards the unenlightened side, so that we must either see the rounding side of the unenlightened edge, or else the reflection of the light of Saturn upon the side of the darkened ring, as we see the reflected light of the earth on the darkened part of the new moon. I will not, however, take upon me to decide which of the two may be the case, especially as there are other very strong reasons which induce us to think that the edge of the ring is of such a nature as not to reflect much light.

Several astronomers have supposed that the ring of Saturn is full of mountains and inequalities, like the moon; and of this opinion Dr Herschel himself was for a considerable time, till happening to observe one of these lucid points with attention for a considerable time, he saw it leave the ring altogether, and show itself as a satellite never before observed. With regard to the ring itself, he concludes his observations in these words: "Upon the whole, therefore, I cannot say that I had any one instance that could induce me to believe that the ring was not of one uniform thickness; that is, equally thick at equal distances from the centre, and of an equal diameter throughout the whole of its construction. The idea of protuberant points upon the ring of Saturn, indeed, is of itself sufficient to render their existence inadmissible, when we consider the enormous size which such points ought to be of to render them visible at the distance we are from that planet.

With regard to the satellites, the Doctor informs us, that he was long convinced of the existence of a fifth; and had he been more at leisure at the time of his discovering those of the Georgium Sidus, he would probably have completed the discovery of the satellites of Saturn also. The fifth was first observed distinctly on the 28th of August 1789, and the seventh on the 17th of September the same year. These satellites, however, do not occupy the place which we should have previously supposed them, being, in fact, the innermost of the whole. The seventh is next the body of the planet itself, and is very small. It revolves at the distance of 27°36' from the centre of Saturn, and seems to move exactly in the plane of the ring; but the Doctor observes, that it is exceedingly difficult to make a sufficient number of observations on it to determine the revolution exactly. He computes its periodical time at 22h 40m 40s. The fifth satellite is next to the seventh, and revolves at the distance of 35°05' from the centre of its primary in 1h 8m 53s 9s. Its light is considerably strong, but not equal to that of the first satellite of former astronomers, which lies immediately beyond it.

The planet Saturn is now observed to have belts or fasciae upon its disk as distinctly as Jupiter. Dr Herschel, on the 9th of April 1775, observed a northern belt on his body, inclined a little to the line of the ring. On the 1st of May 1776, there was another belt observed, inclined about 15° to the same line, but more to the south; and on the following side came up to the place where the ring crosses the body of the planet. On the 8th of April two belts were observed, and these continued with variations, and sometimes the appearance of a third belt, till the 8th of September, when the account of the observations was discontinued. The Doctor remarks, that he generally observed these belts in equatorial situations, though sometimes it was otherwise. Two conclusions, he says, may be drawn from the observations he made this year. "The first, which relates to the changes in the appearance of the belts, is, that Saturn has probably a very considerable atmosphere, in which these changes take place, just as the alterations in the belts of Jupiter have been shown with great probability to be in his atmosphere. This has also been confirmed by other observations. Thus, in occultations of Saturn's satellites, I have found them to hang to the disk for a long while before they would vanish. And though we ought to make some allowance for the encroachment of light, whereby a satellite is seen to reach up to the disk sooner than it actually does, yet without a considerable refraction it could hardly be kept so long in view after the apparent contact. The time of hanging upon the disk in the seventh satellite has actually amounted to 20 minutes. Now, as its quick motion during that interval carries it through an arch of near five degrees, we find that this would denote a refraction of about two seconds, provided the encroaching of light had no share in producing the effect. By an observation of the fifth satellite, the refraction of Saturn's atmosphere amounts to nearly the same quantity; for this satellite remained about 14 or 15 minutes longer in view than it should have done; and as it moves about 2° degrees in that time, and its orbit is larger than that of the seventh, the difference is inconsiderable. The next inference we may draw from the appearance of the belts on Saturn is, that this planet turns upon an axis which is perpendicular to his ring. The arrangement of the belts, during the course of 14 years that I have observed them, has always followed the direction of the ring, which is what I have called being equatorial. Thus, as the ring opened, the belts began to advance towards the south, and to show an incurvature answering to the projection of an equatorial line, or to a parallel of the same. When the ring closed up, they returned towards the north, and are now, while the ring passes over the centre, exactly ranging with the shadow of it, on the body, generally one on each side, with a white belt close to it. When I say that the belts have always been equatorial, I pass over trifling exceptions, which certainly were owing to local causes. The step from equatorial belts to a rotation on an axis is so easy, and, in the case of Jupiter, so well ascertained, that I shall not hesitate to take the same consequence for granted here. But if there could remain a doubt, the observations of June 19th, 20th, and 21st, 1780, where the same spot upon one of the belts was seen in three different situations, would remove it completely." Another evidence that Saturn, as well as the other planets, revolves upon its axis, is drawn from its flattened shape, like that of Mars, Jupiter, and Saturn. On the 31st of May 1781, the disk seemed to deviate as much from a true circle as that of Jupiter, though by the interference of the ring this could not be so well determined as after an interval of eight years. On the 18th of August 1787, the difference between the equatorial and polar diameters was measured, the mean of three observations of the former being $22^\circ.81$, of the latter $20^\circ.61$. From these observations, it appears that the polar diameter of Saturn is to his equatorial diameter nearly as 10 to 11; and that his axis is perpendicular to the plane of the ring.

In a subsequent paper, the Doctor gives up his reasoning against fixed lucid points in the ring, in consequence of having frequently observed them in such situations as could not by any means be accounted for by the satellites. He even attempts to invalidate his own arguments above-mentioned concerning the vast magnitude of the mountains necessary to make them visible at this distance. "As observations (says he) carefully made should always take the lead of theories, I shall not be concerned if such lucid spots as I am now going to admit, should seem to contradict what has been said in my last paper concerning the idea of inequalities or protuberant points. We may, however, remark, that a lucid and apparently protuberant point may exist without any great inequality in the ring. A vivid light, for instance, will seem to project greatly beyond the limits of the body on which it is placed. If, therefore, the luminous places on the ring should be such as proceed from very bright reflecting regions, or, which is more probable, owe their existence to the more fluctuating causes of inherent fires acting with great violence, we need not imagine the ring of Saturn to be very uneven or distorted, in order to present us with such appearances. In this sense of the word, then, we may still oppose the idea of protuberant points, such as would denote immense mountains of elevated surface.

"On comparing together several observations, a few trials shew that the brightest and best observed spot agrees to a revolution of $10^\circ 32' 15''$; and calculating its distance from the centre of Saturn, on a supposition of its being a satellite, we find it $17^\circ 227'$, which brings it upon the ring. It is therefore certain, that unless we should imagine the ring to be sufficiently fluid to allow a satellite to revolve in it, or suppose a notch, groove, or division in the ring, to suffer the satellite to pass along, we ought to admit a revolution of the ring itself. The density of the ring, indeed, may be supposed to be very inconsiderable by those who imagine its light to be rather the effect of some shining fluid, like an aurora borealis, than a reflection from some permanent substance; but its disappearance, in general, and in my telescopes its faintness, when turned edgeways, are in no manner favourable to this idea.—When we add also, that this ring casts a deep shadow upon the planet, is very sharply defined both in its outer and inner edge, and in brightness exceeds the planet itself, it seems to be almost proved that its consistence cannot be less than the body of Saturn, and that consequently no degree of fluidity can be admitted sufficient to permit a revolving body to keep in motion for any length of time. A groove might afford a passage, especially as on a former occasion we have already considered the idea of a divided ring. A circumstance also which seems rather to favour this idea, is, that in some observations a bright spot has been seen to project equally on both sides, as the satellites have been observed to do when they passed the ring. But, on the other hand, we ought to consider, that the spot has often been observed very near the end of the arms of Saturn's ring, and that the calculated distance is consequently a little too small for such appearances, and ought to be 19 or 20 seconds at least. We should also attend to the size of the spot, which seems to be variable: for it is hardly to be imagined that a satellite, brighter than the sixth, and which could be seen with the moon nearly at full, should so often escape our notice in its frequent revolutions, unless it varied much in its apparent brightness. To this we must add another argument drawn from the number of lucid spots, which will not agree with the motion of one satellite only; whereas, by admitting a revolution of the ring itself in $10^\circ 32' 15''$, and supposing all the spots to adhere to the ring, and to share in the same periodical return, provided they last long enough to be seen many times, we shall be able to give an easy solution of all the remaining phenomena. See Phil. Trans. 1790, p. 427.

chemistry, an appellation given to lead.

heraldry, denotes the black colour in blazoning the arms of foreign princes.

of the principal of the Pagan deities, was the son of Coelus and Terra, and the father of Jupiter. He deposed and calumniated his father; and obliged his brother Titan to resign his crown to him, on condition of his bringing up none of his male issue, that the succession might at length devolve on him. For this purpose he devoured all the sons he had by his wife Rhea or Cybele; but she bringing forth at one time Jupiter and Juno, she presented the latter to her husband, and sent the boy to be nursed on mount Ida; when Saturn being informed of her having a son, demanded the child; but in his stead his wife gave him a stone swaddled up like an infant, which he instantly swallowed. Titan finding that Saturn had violated the contract he had made with him, put himself at the head of his children, and made war on his brother, and having made him and Cybele prisoners, confined them in Tartarus; but Jupiter being in the mean time grown up, raised an army in Crete, went to his father's assistance, defeated Titan, and restored Saturn to the throne. Some time after, Saturn being told that Jupiter intended to dethrone him, endeavoured to prevent it; but the latter being informed of his intention, deposed his father, and threw him into Tartarus. But Saturn escaping from thence fled into Italy, where he was kindly received by Janus king of the country, who associated him to the government: whence Italy obtained the name of Saturnia Tellus; as also that of Latium, from latio, "to lie hid." There Saturn, by the wisdom and mildness of his government, is said to have produced the golden age.

Saturn is represented as an old man with four wings, armed with a scythe; sometimes he is delineated under the figure of a serpent with its tail in its mouth. This is emblematic of the fates, which roll perpetually in the same circle. Sometimes also Saturn is painted with Saturnalia with a sand-glass in his hand. The Greeks say, that the story of his mutilating his father and destroying his children is an allegory, which signifies, that Time devours the past and present, and will also devour the future. The Romans, in honour of him, built a temple and celebrated a festival, which they called Sa- turnalia. During this festival no business or profession was allowed to be carried on except cookery; all di- visions of rank ceased; slaves could say what they pleased to their masters with impunity; they could even rally them with their faults before their faces.