the planets. M. BAILLY mentions his invention of the Epicycles, not only with indulgence, but even with commendation, since at that early period it accounted for all the phenomena, and must be allowed to be 'ingenious, notwithstanding the contemptuous manner in which it has been rejected in modern times.

In the second book our Author treats of the instruments invented by the first Alexandrian school, for the improvement of astronomical science.

Astronomical observations were made with increasing degrees of accuracy, until the time of Hipparchus, whom our Author calls the patriarch of astronomy, and whom Pliny denominated the confident of nature. This great man, whose history, genius, and improvements of the science now under confideration, form the subject of the third book, flourished under Ptolomy Philometor a hundred and thirty years before Christ, and treated astronomy with a philosophical spirit unknown before his time. He considered that sublime science under a general point of view, examined the received opinions, passed in review the truths that had been discovered, and pointed out the method of reducing them so far into a system, as to connect them with cach other. The Chaldean doctrine, which was an unphilofophical medley, made up of the result of observation and the suggestions of credulity and superstition, was established in the Alexandrian school before he arose: but he treated ihe determinations of the Chaldeans as Descartes did the systems of the scholastics. -Our Author enters into a long, circumstantial, and interesting detail of the labours and discoveries of this celebrated astronomer, who perceived the inequality of the sun, expressed it in tables, invented the equation of time, the paralJax, and the measure of distances; who undertook and executed a true description of the heavens, and laid the solid foundations of geographical and trigonometrical science. We cannot follow our learned Author in his ample account of these discoveries : the only thing that we can present to our Readers on this and all the other articles, is such a flight sketch of his narration as may indicate the entertainment and instruction which they may expect in perusing this excellent history.

Three hundred years passed between Hipparchus and Ptolomy, who flourished at Alexandria, in the second century, under the empire of Adrian and Marcus Antoninus. This great man was the last ornament of the Alexandrian school. He collected all the observations that had been made before his time, more especially those of Hipparchus and Pollidonius (the only succellor of Hipparchus who had any considerable reputation), and was for a course of ages at the very fummit of astronomical fame, till Copernicus removed him on a sudden from thence,


M m 4

and took his place, which he is likely to keep as long as fun and moon thall endure. Ptolomy collected the result of his labours and astronomical observations in an immortal work, intitled the Almageft, which was to furnish astronomers of future times with the means of surpassing their ancient guides

. This work forms the communication between ancient and modern astronomy, and contains methods, or the germs of methods to use our Author's expression), which are still employed in our times. The account of this great astronomer is the subject of the fourth and fifth books of this history.

In the sixth and seventh, M. Bailly treats of the astronomical knowledge of the Arabians, the modern Tartars, the Chinese, and even of some of the American tribes or nations. As to the Arabians, he paints their fanatical passion for conquest

, and the devastations that accompanied it, in the most striking manner : he represents these booted disciples of Mahomet, ruthing into Egypt, making themselves masters of Alexandria, destroying that famous library, which was (if we may use that expression) the focus, where all the rays of science and learning, that proceeded from all parts of the globe, were united and col. lected :-he describes them heating their stoves with the precious treasures contained in that immense collection; he represents sciences and letters as perishing in the ruins of that library

, and the Alexandrian school (which had been founded 280 years before the Christian æra) expiring in the middle of the seventh century. M. Bailly, indeed, turns the medal, and presents the Arabians in an aspect that, at least, makes some amends for their depredations: he tells us wittily, that bårbarians are like children, who destroy whatever comes into their hands, and foon after regret what they have destroyed, cry for it, and would be glad to have it back again. Thus, says he, the Arabians, after having burned the library, and dispersed the philosophers of the Alexandrian Tchool, looked earnestly for the light, which they themselves had extinguished, and from the ashes, which their odious barbarity had accumulated, and were picking out eagerly, before the century ended, the precious remains of erudition and science that had escaped the fames. But though he allows them the honour of some knowledge and fome discoveries, such as that of the motion of the sun's apogee, the knowledge of the pendulum, and some other useful observations; yet upon the whole le considers them, as only commendable for having preserved the remains of the sacred fire, which they had, at first, attempted to extinguish, and represents them as more formed for judiciary astrology than for astronomical science.

In the eighth book M. BAILLY follows astronomy into Eu. rope, After having contemplated it in its imagined grandeur (imagined by him in his chimerical hypothesis of the Atlantis) in



the early ages, and amidst the changes and shocks it received, from the revolutions and convulsions of nations, as well as in the improvements and advantages it acquired from the protection of learned princes and the labours of men of genius, he considers the noble edifice as indebted for the completion of its grandeur to Europe. Its grandeur, indeed, is not yet completed; but great things have been done, and are ftill doing for this purpose. Italy and Germany began the work : England and France have accelerated its construction ; at this very moment all-nations feem to join hands to raise the building, and it is difficult to say (we use our Author's words) where the summit of its majestic grandeur will stop. In this book M. BAILLY shews the obligations which aftronomical science has, in this part of the globe, to the talents, genius, researches and penetration of Purbach, Regiomontanus, and Waltherus. The first of these three famous astronomers composed a theory of the planets, in which he endeavours to correct the system of Ptolomy. John Muller (generally known under the name of Regiomontanus, which is the Latin word for Kuningsberg, the place of his nativity) was the disciple of Purbach, and surpassed his master. He is considered as the inventor of the Ephemerides, and in the year 1474, Pope Sixtus IV, having conceived a design of reforming the calendar, sent for him, as the propereft person to execute that design, and made him Archbishop of Ratisbon. Two years before this, in 1472, he observed a comet, which was the first that was noticed in Europe. He was intimately persuaded of the motion of the earth, and would perhaps have anticipated Copernicus is the reformation of astronomy, and the re-invention of the true system of the world, had he not been carried off by the plague, at the age of forty. Waltherus was the friend of Muller, who had affifted him by his liberal contributions to the expence that he was at in the construction of astronomical instruments, and obtained much instruction from his conversation while he lived, and from his papers after his death. He was suspected of having published some of Muller's productions as his own; it cannot, however, be denied, that he was a man of fagacity and genius, of which his use of clocks, for the measure of time in astronomical observations, is an evident proof.

The grand revolution that happened in the history of astronomy from the rise of Copernicus, towards the conclusion of the fifteenth century, to the time of Ticho-Brahe, who was born in the midst of the sixteenth, employs our Author in the ninth and tenth books of this hiftory, which conclude the first volume. In such a sublime flight as that of Copernicus, who forbids us to believe the motion that we fee, and engages us to consider as certain, that of which we have not the least perception or feeling; who represents the sun and the stars as motionless, and our heavy 3

globe globe whirling itself with rapidity about the great source of light, who could have imagined, that he had hit upon the truth, and found out the real system of the universe ? His discovery became a fundamental truth in aftronomy, and he treated that science with the creating spirit of a philosopher and a legislator. He did not, however, bring the art of observing to perfection, an art which requires rather patience and fagacity than invention and genius.

The science of astronomy, notwithstanding this noble difcovery, ftood in need of facts and observations; and these were furnished in a rich abundance by that spirit of afliduity, curiosity, and detail, that diringuished Ticho-Brahe, whom the impulsion of genius and nature rendered an astronomer; while an eclipse of the fun in 1560 gave the word. The labours of Ticho-Brahe are well known : our Author unfolds, in an ample narration, their nature and their merit: he does justice to this great man by acknowledging, that his fyftem is not incompatible with mathematical principles, and even that it corrects with dexterity the absurdities that the hypothesis of Ptolomy had introduced into the wife arrangements of the universe. But he attacks the system of the Danish astronomer upon the principles of natural philofophy, and that victoriously :-he blames him for not having adopted the system of Copernicus, and for running the risk (by fubftituting another in its place) of plunging the truth anew in the very abyss from which it so lately emerged.

It is a mortifying instance of the infirmity of human nature, even in its best appearances, that the greatest part of the eminent astronomers already mentioned, were tainted with the superstitidus nonsense of judicial astrology. It was not only the Arabians who gave into this folly, -it was not only an Abu-elMaafar, who believed, amidst the noblest efforts of learning and genius, that the Jewish, Egyptian, Turkith, and Christian reLigions were derived, respectively, from the conjunction of certain planets : but Hipparchus, Ptolomy, Purbach, Muller, Ticho-Brahe, and many others laboured under a similar folly ; and this gives our Author occasion to say several good things on this diseafe of the human imagination, in an excellent disertation on astrology;

This volume is terminated by feveral instructive illustrations relative to astronomical science, a curious list of the oriental astronomical manuscripts, that are to be found in some of the principal libraries of Europe, and an indication of the works of the principal astronomers: the whole accompanied with thirteen plates accurately engraven.

Kepler feems to be the astronomical hero of our Author. He was a native of Wirtemberg, and was born in 1571. According to M. BAILLY, Kepler was the true founder of modern aftror nomy, nay one of the greatest men that ever appeared on earth. Our Author is not the first who has spoken of Kepler with enthusiasm, though perhaps he goes too far, when he exalts him above Copernicus and Ticho-Brabe; who, he affirms, could have no advantage over the ancient founders of astronomy, of whose labours we have some remains in the tables of the Pere fians, Indians and Siamele; whereas Kepler destroyed the edifice of the ancients to erect another more permanent and more sublime. There is no doubt of Kepler's extraordinary genius, discoveries and merit: but if Copernicus had no advantage over the ancient founders of astronomy, what could induce our Author to call his labours the epocha of a grand revolution in afronomy in the preceding volume, and to say in this, when he is introduciog Kepler, that at the first appearance of the Copernican system, truth was new and without support, and stood in need of such a genius as Kepler to discern its grandeur ? All this is not very consistent.--If in affirming that Copernicus had no advantage over the ancient astronomers, he has in view bis ancient primitive nation, the faultless monster which the world ne’er saw,- which had brought astronomy and the other sciences to perfection, and of whose science Copernicus and the rest had only recovered some fragments, he may, in this respect, say the same thing of Kepler that he did of Copernicus ;—and if he bas not in view this primitive nation, but the astronomers whose names and labours have come down to us from an early antiquity, then it is not true that Copernicus, Ticho-Brahe, and others of that class had no advantage over the ancient founders of astronomy.


Be that as it may, Kepler was, indeed, a luminary of the first magnitude in the astronomical world, and there were even streaks of genius in his most extravagant fingularities. Descartes, Gregory, and even the immortal Newton acknowledge their obligations to him, on many occafions; and he will certainly be revered, as long as true genus and astronomical science remain in esteem among men. Kepler adopted, without hesitation, the Copernican fyftem; but he went much farther: he discovered the true forms of the planetary orbits, proved that they were elliptical, and not circular; and it is this discovery, that, according to M. BAILLY, fet astronomy on a new and solid balis, annihilated the fyft m of the ancients, and went even beyond the science of the famous primitive people, who, by what we can learn (fays our Author) from the veft goes of antiquity, had got no farther than the knowledge of circular motions. Kepler's ge-nius and labours are admirably defcribed and appreciated by our Jearned, ingenious and eloquent Author:- bethews us this great man in all his aspects, discovering the proportions of the celeftial orbits, and thosc laws of their motions that laid the four


« VorigeDoorgaan »