Years of Chrift. 1759 Years fince. Prince Ferdinand's total Defeat of the Freneb near 1759 Kew Bridge built. 1759 Ticonderoga and Niagara taken by the English. 1759 Crown Point taken by the English. 9 9 9 1759 Quebec taken by the Engli under General Wolfe, who was killed in the glorious Conqueft. 9 1759 Admiral Hawke beat the French Fleet off Belle-Ifle, and defeated their Defign of Invafion. 1760 Black-Friars Bridge begun. 9 8 1760 King George II. died October 25, and King George III. began his Reign. 8 1761 King George III. and Queen Charlotte crowned Sep tember 22. 1762 A great Snow, for eighteen Days together, in February and March. 1763 A General Peace with France and Spain. 7 6 5 1763 Prince Frederick born Auguft 16 1765 Prince William-Henry born August 21 Of the four Quarters of this Year 1768. HE Winter Quarter begins December 21, 1767, at T18 minutes paft 6 in the afternoon; then the fun en ters the first point of Capricorn, and the earth into Cancer. ΤΑ T The Spring Quarter, AKES its beginning on the 21ft of March, at 2 in the morning; then the fun enters the fign Aries. The Summer Quarter, BEGINS when the far enters the first point of Cancer night. it will be on the 21ft of June, 21 minutes paft mid The B The Autumnal Quarter, EGINS September the 23d day, at 2 hours p. m. the fun enters the equinoctial fign. night of equal length. Day' and SELENOGRAPHY, or the PHILOSOPHY of the MOON. WHA HAT is the etymology of the word felenography? It is compounded of a Greek word, the moon, and a defcription of the moon. To speak of the moon in the fingular as if there was but one, whereas, just now, you will number our moon with feveral others; there are several other moons, as Jupiter hath four moons, and Saturn hath five moons round their bodies, as the earth has bat one; but, because we know little more of them than their number, motion, and diftances from their primary planets, we fhall omit them here, and speak of them, together with their primaries, by and by. Well, fince the moon is favoured with the pre-eminence to be confidered alone, pray what do we first obferve in her? What It is found that the body of the moon is a large dark, opaque, fpherical body, like to our earth in matter and form. proportion doth the moon bear to the earth in its magnitude and denfity of matter? The bulk of the moon is to that of the earth as 5 to 258; that is, the earth is about 50 times (at least) bigger than the moon; the density of the moon is to the density of the earth as 4891 to 4000, or as 11 to 9. We can tell you the particular dimenfions of the moon's body in English measure. The diameter of the moon is 2175 English miles, her circumference therefore must be 6829 miles; whence the fuperficies of the moon will contain 1415440 fquare miles, and her solid content will be 5386333000 cubic miles. On what do these measures depend?. On the distance of the moon from the earth, which fome aftronomers make 59, foine 60, and fome 61 femidiameters of the earth, that is, about 238920 English miles; whence the diameter of the moon's orb will be 477840 miles, and the circumference thereof 1500418 miles, which therefore is the journey the moon performs in every revolution. Then we do allow the moon to move about the earth every day, from eaft to weft, though we deny this to the fun? The moon doth indeed move about the earth, and that in about 27 days, 7 hours, and 43 minutes, at a mean rate; but this motion is not from east to west, but, on the contrary, from w eaft, every day, about 13 degrees and 10 minutes. How comes it then to appear to do thus? By reafon of the daily motion of the earth about its own axis, from weft to eaft, once in 24 hours ;. which maketh the fun, moon, and the heavenly bodies appear to move the contrary way, from eaft to weft, in the fame time. Pray why do we see the moon rife and fet above an hour later every day than another? (See Mr. Martin's Philofophical Grammar) I shall make this eafy to be conceived: Thus, fuppofe T to be the globe of the earth, W SEN the orb of the moon: Let A D reprefent the horizon; in which let the moon be on any day at her rifing and fetting in E and W. Now, because the moon moves every day about 13° 10' from weft to eaft, let that diftance be reprefented in the moon's orb, by W F and E H; therefore, at the fame time in the following day, the moon will be under the horizon at H at her rifing, and above the horizon at F at her fetting; Therefore, the furface of the earth must turn from A to B, and from D to C, before the moon will be again in the horizon at her rifing or setting; which motion from A to B, or from D to C, takes up about 48 minutes more or less. See Newton Princip. lib. III. Gregory's, Whiften's, and Keill's aftronomy; allo Mr. Leadbetter's books of aftronomy. See it demonftrated in this diagram. You may perfectly underftand the meaning of this phænomenon. The moon hath an other other motion: She revolves about her own axis just in the fame time the performs one revolution about the earth, viz. in 27 days, 7 hours, and 43 minutes; because, at the fame times, we always fee the fame face or fide of the moon; but this could not happen, unless a proper motion about its axis turned every day juft to much of the moon's body to the earth, as her periodical motion turns from it. This must be a wonderful harmony and corret, pondence of motions. But, what is the form of the moon's or bit ? The moon's orbit is elliptical, but is perpetually changing, and never continueth the fame fpecies, or of the fame figure. The causes of the inequalities of the motions of the moon, and the form of her orbit, are the different attractions of the fun and earth, the eccentricity of her orb, and the obliquity of the axis of her daily motion. We agree the moon receives all the light fire fhines with from the fun, and, by reflection, conveys it to us in the fun's abfence. The reason why some parts of the moon's face look dark, and the others light. The bright parts of the moon's body are the more eminent parts of land which reflect the light of the fun, as hills, moantains, promontories, iflands, &c. and the dark parts of the moon are thought to be feas, lakes, rivers, fens, &c. by fome; and, by others, they are faid to be fhaded valleys, caverns, pits, &c. but, in truth, they represent both water and land with fhaded places; for, neither of these reflecting lights, they muft appear dark, and not bright. We fuppofe the moon to be inhabited, I find? I have heard there are fome of that opinion. To what end elfe can ferve the diftribution of land and water, mountains and valleys, caverns, pits, &. Befides, an atmosphere of air, and thereby winds, clouds, rains, and other meteors of confequence, has been lately difcovered about it: No doubt but they ferve the purposes there, as here, to nourish and fuftain men, beafts, and vegetables, They who would fee the manner of measuring a lunar mountain, may confult Mr. Derham's Aftro-Theol. Book V. Chap. 2. ་ Of URANOLOGY, or the Doctrine of the HEAVENLY BODIES. HE of the word uranology; of a Greek Tgina), and it fignifies a difcourfe of treetife of the heavens, or heavenly regions, and bodies therein, W We do call the heavens, or heavenly regions, thofe regions or fields of æther which lie all round us, about the atmofphere; in which are fituated all the fhining bodies, the fun, planets, comets, and itars, and wherein they perform all their motions. It will be proper for us to begin our converfation on these celestial fubjects. We will firft begin with heliography: By heliography is to be understood a philofophical defcription of the fun. Well, it seems congruous to begin with what you make the center of our fyltem, as we call it: The fun is a huge body of light or fire, whence all the other planets receive their Ights, and, by whole emanations of rays and beams of light, the whole fyftem of beings about us are illuminated and made vifible. We cannot tell any thing of the fun's bulk. The diameter of the fun is computed to be 822148 English miles, and its bulk or folid content at about 100000, or a million of times greater than the globe of our earth. A ftupendous magnitude! and we do fuppofe it to be all fire; and therefore fome have thought it to be the place of hell. The density or thickness of the fun is to the density of Saturn as 100 to 67; to the denfity or thickness of Jupiter, as 100` to 94; and to the denfity of our earth as 100 to 400, or as 1 to 4; and therefore the fire of the fun must be prodigiously intense, yea, almoft folid; the light and heat must be inconceivably great near the fun's furface; yes, great indeed. Sir Ifaac Newton faith the fun's light and heat, at the diftance of the body of Mercury, is feven times as great as the greatest with us; and therefore our water there would be for ever boiling hot, till it was all evaporated and boiled away. J ECLIPSES in this Year 1768. HERE will be fix eclipfes this year: Three of the fun and Tthree of the moon, but thofe of the moon only will be vi fible to the inhabitants of our horizon in Great Britain. The first is a partial and a visible eclipfe of the moon, on Monday, being the fourth day of January, which will be seen at Stamford, if the air be clear, in the morning; and may be expected to be agreeable to the following type and calculation : |