But what has been faid will fuffice to fhew, that very probably Saturn has an atmosphere of a confiderable density. The next inference we may draw from the appearance of the belts in Saturn is that this planet turns upon an axis which is perpendicular to the ring. The arrangement of the belts, during the courfe of fourteen years that I have obferved 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 fouth; and to fhew an incurvature answering to the projection of an equatorial line, or to a parallel of the fame. When the ring clofed up, they returned towards the North; and are now, while the ring paffes over the center, exactly ranging with the fhadow of it on the body; generally one on each fide, with a white belt close to it. When I fay, that the belts have always been equatorial, I pafs over trifling exceptions, which certainly were owing to local caufes. The step from equatorial belts to a rotation on an axis is fo eafy, and, in the cafe of Jupiter, fo well afcertained, that I fhall not hesitate to take the fame confequence for granted here.' Another argument is the difference between the equatorial and polar diameters, which appear to be 22.81, and 20.61 respectively, nearly in the ratio of 11 to 10. Information of a more extensive nature may be expected from our author's continued obfervations on this planet, which he promises to purfue. Art. II. Aftronomical Observations on the Planets Venus and Mars, made with a View to determine the heliocentric Longitude of their Nodes, the annual Motion of the Nodes, and the greatest Inclination of their Orbits. By Thomas Bugge, F.R.S. Regius Profeffor of Aftronomy at Copenhagen, &c. &c.-The heliocentric longitude of the defcending node of Venus was on the 25th of Auguft, 1786, at 8h. 39′ = 8° 14° 44′ 38′′, which our author thinks may be depended on to 10" or 15": the difference from M. la Lande is only-37". The annual motion of the node 3037". The inclination of the orbit of Venus to the ecliptic, is faid to be 3°, 23, 38.6". The heliocentric longitude of Mars' afcending node is, from our author's obfervavations, 13, 17°, 54′, 24.2, on Dec. 7th. 1783; 20, 23′, 39′′ mean time at Copenhagen: the most probable annual motion of the node 28.2. The inclination of the orbit of Mars is correct within two or three feconds in the tables of Dr. Halley and M. de la Lande. = "I shall conclude this paper with the oppofition of Mars according to the foregoing obfervations. The oppofition of Mars to the fun happened 1788, January 7, at 8h. 19' 32" true time; she apparent geocentric longitude of Mars at that moment 3'. 17° 17' 8" and the geocentric latitude 4° 4' 3" N. Saturn was in oppofition to the fun, Auguftzg, zob.51'11" true time; the ap parent longitude 11. 7° 31′ 34′′, and latitude 1° 59′ 33 S. The new planet was in oppofition to the fun January 18, ch. 21′ 33′′ true time, the longitude=3. 28° 10′ 7′′, and latitude o° 34′ 35′′ N.' Art. III. An Account of fome Luminary Arches. In a Letter from Mr. William Hey, F. R. S. to the Rev. Jofeph Prieftley, LL. D. F. R. S.—Mr. Hey, in this paper, defcribes many luminous arches; we have seen several fimilar ones, and have no doubt of their being phænomena fimilar to the northern lights. We have often feen ftars of the fecond magnitude obfcured by an aurora borealis.. Art. IV. Extract of a Letter from F. J. H. Wollafton (dated Sydney College, Cambridge, February 24, 1784), to the Rev. Francis Wollaston, LL. B. F. R. S. Art. V. An Account of a Luminous Arch. In a Letter from the Rev. Mr. B. Hutchinfon to Sir Joseph Banks, Bart. P. R. S. Art. VI. Extract of a Letter from J. Franklin, Efq. relative to a Luminous Arch. Communicated by Sir Jofeph Banks, Bart. P. R. S. Art. VII. An Account of fome Luminous Arches. In a Letter from Edward Pigott, Efq. to Sir Henry C. Englefield, Bart. F. R. S. Art. X. On the Height of a Luminous Arch which was feen on Feb. 25, 1784. By Henry Cavendish, Efq. F. R. S. and A. S. All these descriptions relate to the fame luminous arch, which Mr. Cavendish fuppofes must have been within 71 miles, and above 52 miles in height. The common aurora borealis has been fuppofed, with great reafon to confist of parallel itreams of light fhooting upwards, which by the laws of per pective, appear to converge towards a point, and when any of thefe ftreams are over our heads, they appear actually to come to a point and form a corona. Hence, from analogy, it feems not unlikely, that these luminous arches may confifl of parallel ftreams of light difpofed fo as to form a long thin band, pretty broad in its upright direction, and ftretched put horizontally to a great length one way, but thin in the oppofite direction. If this is the cafe, they will appear narrow and well defined to an obferver placed in the plane of the band; but to one placed at little distance from it, they will appear broader, fainter and less well defined; and when the oble ver is removed to a great distance from the plane, they will vanish, or appear only as an obfcure ill-defined light in the sky,' • Suppofing Suppofing the hypothefis to be well founded, the height above determ ned will answer to the middle part of the band, provided the breadth of it was fmall in respect of its diftance from the earth, but otherwife will be contiderably below the middle. If the breadth of the band was equal to the distance of its lower edge from the earth, the height of the lower edge would be three fourths of that above found; and if the breadth was many times greater, would be half of it.' Art. VIII. Experiments on the Analyfis of the Heavy Inflammable Air. By William Auflin, M. D. Fellow of the College of Phyficians; communicated by Charles Blagden, M. D. Sec. R. S.-Dr. Auftin decompofed the heavy inflammable air in different ways, and feems to have shown that it confifts of light inflammable and phlogifticated airs. This opinion, which he formerly fuggefted, is now fupported by different experiments. He analysed the heavy air, by paffing the electrical shock through the veifel which contained it, and by adding dephlogifticated air or fulphur. The heavy inflammable air is nearly allied to charcoal, and each appears, in our author's opinion, to be combined with a proportion of phlogifticated air. In the latter, however, the light inflammable air feems to be wanting. Some remarks on fixed air, and its appearance in different proceffes, are fubjoined; but our author adds nothing to what Dr. Priestley has obferved on this subject. He feems to believe in the compofition of water, and thinks this element decompofed by vegetation, affording inflammable air, which, with the phlogifton imbibed by the plant, forms the heavy inflammable air. Art. IX. Some Account of the Strata and Volcanic Appearances in the North of Ireland and Western Islands of Scotland. In two Letters from Abraham Mills, Efq. to John Lloyd, Efq. F. R. S.-Our author proceeds from the Giant's Causeway to Staffa; coafts along the northern parts of Ireland, and examines fome of the Western Islands, with the eye of a mineralogist. It is not easy to follow him without a map, and, even with its affiftance, it is difficult to abridge this minute detail. The whole coaft appears to be volcanic, perhaps, as Mr. Mills fuggefts, from a crater, which is now covered by the Atlantic. The most important circumftance is our author's finding the lava and bafaltes fo intimately connected with granite and gneifs, while we have reason to fuppofe that neither of thefe rocks afford the fubftance of lavas. His remarks are not, however, fo particular as to enable us to fay how the granite and the lavas are connected. In fome inftances it is evident, that the lava has found its way under the granite, and raifed it. In others, it has flowed over the granite, as, in the north of Ireland, it refts on calca reous reous earth. But there are fome appearances, which lead us to think that the granite has been burnt, for the lefs changeable ingredients of this primitive ftone are found in the lava. The conclufion is not yet, however, fo clear, as to be rested on securely. What has been ftyled Fingal's Cave in Staffa, Mr. Mills informs us, from the authority of a schoolmaster at Icolm Kill, is called Fein, The Melodious or Echoing Cave.' A bed of coal is found in Ireland and the Hebrides, 'incumbent on and furmounted by a mass of lava, evidently fublimed after the formation of the lava;' and we have formerly quoted a fimilar inftance from Baron Born's Travels. The whyn-dykes are veins of lava, often bafaltic, generally ftrait, though occafionally inflected: they fometimes rife three or four feet above the furface, forming natural boundaries, from which they have their name. Art. XI. Obfervations on Refpiration. By the Rev. Jofeph Priestley, LL. D. F. R. S. - Dr. Priestley's experiments we alluded to when we spoke of Dr. Girtanner's Memoir, and we did not object to that gentleman's fyftem of dephlogisticated air being abforbed by the lungs, though different from the usual opinions, because we knew that it had been confirmed by our author. Suppofing fixed air to be compofed of pure air and phlogifton, Dr. Prieftley found that one-fourth of the weight of fixed air is phlogifton, and the other three-fourths dephlogiflicated air. Of the pure air, it appeared that three times as much entered the blood as was employed in producing the fixed air expired. Art. XII. An Account of the Trigonometrical Operation, whereby the Distance between the Meridians of the Royal Obfervatories of Greenwich and Paris has been determined. By Major-general William Roy, F. R. S. and A. S- Of the 270 pages of which this volume confifts, 160 are employed in this article. It is indeed, in many refpects, extremely valuable, but incapable of abridgement or analyfis: this is a national work, which will reflect the highest honour on the reign in which it was executed, and thofe who executed it. The last part is the ufual meteorological journal for 1789, in which the leaft height of the therinometer was 174° on the morning of the 5th of January, but cold of this feverity was tranfitory. It was often in this month at 249. The highest point was 741, evidently from the heat of the fun, as the heat in the preceding and following obfervations was only 60, and the indoor thermometer at the fame time was 69. The mean heat of April was 47°.2; and the rain 21.976 inches. Letters Letters on Education, with Obfervations on Religious and Metaphyfical Subjects. By Catherine Macaulay Graham. 8vo. 75. Boards. Dilly. THIS "HIS lady's Effay on the Immutability of Moral Truth,' we examined in our LVIth volume, p. 348. and chearfully praised an able and interefting difcuffion of an important fubject. We fear the world was not equally indulgent or just, fince many parts of the metaphyfical doctrine are now reprinted in an improved form. On these indeed much of her system depends, and we think he has adorned it more advantageously. Her ftyle is more perfpicuous, her illuftrations more clear, and the periods of a mile' are not now extended to half a furlong. The first part is more ftrictly confined to education, and the fecond is employed in examining the political confequences of different fyftems. The laft part relates to the origin of evil, Bolingbroke's Philofophy, the doctrine of the Stoics, and the questions relating to free-will and neceffity. The first part, therefore, will be the principal object of our attention, though we may perhaps add a few words on our author's fyftem in the fecond. Mrs. Macaulay Graham begins with fome introductory reflections on the univerfal diffufion of happiness, founded on the benevolence and the juftice of the Deity; and her opinions on this fubject are rational and juft, though we think the has started an objection with respect to inftinct and reason, which he has not clearly answered. To examine it fully would detain us too long from our principal object. The queftion of public and private education is next confidered; but it relates only to the enquiry how far education fhould be under the direction of the legislature. Our author fees more numerous difadvantages than benefits refulting from a public education. It is in the third Letter that Mrs. Graham engages more particularly in the great bufinefs of education, and it may be divided into the corporeal or medical treatment, and the improvement of the mind or the developement of its varied faculties. The management of children in early infancy was for a long time erroneous, though Nature, notwithstanding every disadvantage, continued with little change; for those who did not fall victims to the fyftem of the nursery, grew up without feeling any mental difadvantages: though mens fana in corpore fano be the acmè of perfection; and though our corporeal health be in fome degree united with vigour of mind, the connection is not fo ftrong, as fome authors have fuppofed, and much lefs is the ftern virtue of an ancient Roman, or the patriotism |