465 Of the influence of the aurora borealis Similarity between electricity and magnetism General state of the weather in a stationary barometer 565 Jones on the fuperiority of the northern hemifphere 567 Conclufion References to the plates of vol. 3 and vol. 4 579 573 ERRATA. Vol. 4, page 226, line 3, for 38 millions of miles, read 18,717,442,690,526 miles. Page 296, line 12, for by read be, LECTURES ΟΝ NATURAL PHILOSOPHY. ON ASTRONOMY. HA LECTURE XXXVII. OF THE COPERNICAN SYSTEM. AVING fhewn you the appearances of the heavenly bodies as feen from the earth, it will be now proper to fhew you why the motions of the planets appear to us fo different from what they really are. One of the ends for which man was formed, is to correct appearances and error by the investigation of truth; whoever confiders him attentively from infancy to manhood, and from manhood to old age, will find him ever bufy in endeavouring to find fome reality to fupply the place of thofe falfe appearances, by which he has hitherto been deceived. Thus, it is the bufinefs of the prefent Lecture, to correct the errors that arife from appearances in the heavens, and to prove the truth VOL. IV. B of of the Copernican Syftem, which is now generally received, because it rationally accounts for, and accords with the phenomena of the heavens. In this fyftem, the fun is placed in the center, and the earth and other planets revolve round him as their center. There are, however, ftrong reafons for believing that fome of the fages of antiquity were acquainted with the true folar fyftem as revived by Copernicus. It was the univerfal doctrine of the Pythagorean fchool, and is clearly marked out as fuch by Ariftotle: for thefe, fays he, affert that fire is in the midst of the world, and that the earth is one of the heavenly bodies. He afterwards fpeaks of a fet of men, who held a fyftem effentially fimilar to that of the modern Semitychonic. Eudemus, in his history of aftronomy, as cited by Anatolius, fays, that Anaximander was the first who discovered the earth to be one of the heavenly bodies, and to move round the center of the world. Ariftarchus held that the earth is carried round the fun, in the circumference of a circle, of which the fun itfelf is the center; and that the fphere of the fixed ftars is fo immense, that the circle of the earth's annual orbit bears no greater proportion to it, than the center of any fphere bears to it's whole furface. Philolaus, and others, declared the motion of the fun, round about the earth, to be only apparent. They faw and felt the importance of his globe over our's, and fuppofing it's influence to extend to much larger bounds than that of the earth, they placed it in the center of the univerfe. Among the Romans, we find that Numa built a temple to reprefent, as Plutarch interprets it, the fyftem of the Those that want further information on this head, may con the heavens, with a facred fire in the center of it. Thus alfo in the Jewish tabernacle, the feven lights had a reference to the feven chief lights of the heavens. Hence alfo the heavens are called in facred writ the tabernacle of the fun; the whole of our fyftem dwelling within his influence. The foregoing citations are, we prefume, fufficient to fhew that the ancients were not ignorant of the true folar fyftem. But ftill it was no general perfuafion, nor does it seem ever to have been mentioned after the time of Ptolemy, who adopted that fyftem which now goes under his name; his fyftem, though erroneous, was ingenious; with it the world was content for many ages. It was then confidered as founded upon invincible demonftration; as a facred truth that could not be weakened by the powers of controverfy, or fhaken by the fluctuations of opinion. But at the appointed time when it pleased the SUPREME DISPENSER of good gifts to restore light to a bewildered world, and more particularly to manifeft his wifdom in the fimplicity as well as the grandeur of his works, he opened the fcene with a revival of found aftronomy.* This obfervation of the prefident of the Royal Society, is well worthy your attention; it will open your views of DIVINE PROVIDENCE, which is a topic that ought to be fet in every poffible light that can make it either more clearly, or more generally understood. If you look through the hiftory of past ages from the early periods of the pastoral B2 fult the notes to Sydenham's tranflation of the Rivals of Plato, Duten's Inquiries into the Origin of the Discoveries attributed to the Moderns; Jones's Effay on the first Principles of Natural Philofophy; Baillie Hiftoire de l'Aftronomie ancienne. * Sir John Pringle's Six Difcourfes, p. 97. |