381 



COPERNICUS, NICOLAUS. 



COPLESTON, REV. EDWARD, D.D. 



that of the earth, if tho radii of their orbits be made large enough. 

 He draws a diagram of the system in the manner now usual, and 

 concludes with the following words, which must be considered as the 

 first announcement of the system: " Proinde non pudet nos fateri 

 hoc totum, quofi luna pnecingit, ac centrum terrse per orbem ilium 

 magnum inter caeteras errantes Stellas annul revolutione circa solem 

 transire, et circa ipsum esse centrum mundi : quo etiam sole iinmobili 

 permanente, quicquid de motu soils appatet, hoc potitis in mobi^jtate 

 terrae veriticari," &c. It must be observed that he lays down a sphere 

 fur the fixed stars so distinctly, that his commentator Muler finds it 

 necessary to remind the reader that he does not name the spheres of 

 the planets. But we shall presently see that he could not divest 

 himself of the idea, that the primitive motions of the planets were such 

 as would be caused by their being fixed in immense crystal spheres 

 which revolve round the sun. 



Before proceeding further it will help us here to observe, that 

 Copernicus does not in the smallest degree attempt to answer the 

 mechanical objections to the earth's motion, which were urged with 

 success against his system till the time of Galileo. The laws of motion, 

 as then explained, and as ad in it te 1 by Copernicus himself, were alto- 

 gether insufficient to explain why, if the eirth moved, a stone should 

 fall directly under the point from which it is dropped. No explanation 

 of such difficulties is given by Copernicus, nor can we find (nor did 

 Delambrj find) that they are even alluded to as an element of the 

 question. If the mechanics of Copernicus had been true, the system 

 of Copernicus would have been physically impossible. Now this is an 

 essential element in the character of a discovery, which is materially 

 altered if that which is advanced as true be advanced on false grounds. 

 It is true that fire burns, and it is true that two and two make four; 

 but it is false that two and two make four because fire bums. We 

 give no credit to the Pythagoreans, if it be true, as asserted, that they 

 placed the sun in the centre of the planets because they thought fire 

 the mo*', excellent of all tilings. We may consider the omission of 

 Copernicus in two different lights. The first is, that he saw the 

 mechanical difficulties, but was so struck by the simplicity of bis 

 astronomical system that he thought it more probable than the 

 mechanics of hU day, and suspected that future researches would 

 produce laws of motion which should allow of the possibility of bis 

 system; and thinking thus, he judged it more wisely not to enter 

 upon the mechanical question, so as thereby to shock two sets of 

 received opinions at once. This would do honour to his sagacity ; but 

 unfortunately, the single sentence below alluded to, the equestrian 

 similf, prevents us from supposing that if he considered the subject 

 mechanically at all, he was other than satisfied with his own conclu- 

 sion, " Cum ergo motus circularis sit universorum, partium vero etiam 

 rectus, dicere possumus manere cum recto circularem, sicut cum 

 cegro animal." The word in italics must be a misprint for eguo, as 

 remarked by Muler. The latter distinctly points out that this is 

 meant to explain the difficulty of a falling stone, and adds, 'Sententiae 

 hujus veritas dependet ex hypothesi Coperniciana ;" that is, the truth 

 of the proof depends upon that of the thing proved. He should have 

 said (an<1 possibly did mean), that upon the truth of this sentence the 

 Copernican hypothesis depends, so far as it was proved by Copernicus 

 himself. Our readers now must begin to have an idea how great an 

 injustice haa been done to those who found better reasons for the 

 co-existence of rectilinear and circular motion, by the attachment of 

 the name of Copernicus to the present cojtuical system. 



The second method by which we may suppose Copernicus to have 

 reconciled difficulties, is the actual assertion made both by himself 

 and Osian.ier, that the hypothesis of terrestrial motion was nothing 

 but an hypothesis, valuable only so far as it explained phenomena, and 

 not considered with reference to absolute truth or falsehood. It is 

 usual to consider the expressions in question entirely as a concession 

 to general opiuion, and as intended either to avoid the Inquisition, or 

 to iniluce those to look into the book who would otherwise have put 

 it aside as anti-Moaaicnl and heretical And though there may be 

 some truth in this, we are on the whole inclined to suspect that the 

 hypothetical bypothesin, as we may term it, really did bias the mind 

 of Copernicus much more than has been supposed. We do not at all 

 concede that the interference of ecclesiastical power was as likely in 

 the cose of the Prussian priest of 1540, as in that of the Italian lay- 

 man of 1633. Nothing in more common than to view the middle 

 ages as a whole, without noticing the ebbs and floods of power and 

 opinion. The epoch contained between the last Lateran Council and 

 that of Trent, in which the work of Copernicus was written, printed, 

 and piibliuhe 1, was sufficiently occupied by diocesan councils, both 

 against Luther, and on the reformations in discipline, of which the 

 necessity began to be perceived. It appears to us far the most likely 

 that the mind of Copernicus must have balanced between the two 

 views we have described, and probably must have inclined different 

 ways at different time*. 



We now come to the brightest jewel in the crown of Copernicus, 

 the method in which he explained, for the first time and with bril- 

 liant success (eo far as demonstration went, as before described), the 

 variation of the seasons, the precession of the equinoxes (book i. cap. 2, 

 book iii., and book vi. cap. 35), and the stations and retrogradations 

 of the planets. The latter point is fully made out, and in the manner 

 now adopted, so far as the qualities of the phenomena are con- 



cerned : we shall presently sec the method of rectifying the quantities. 

 With regard to the variation of the seasons, Copernicus explains it 

 rightly, from the continual parallelism of the earth's axis. But he 

 cannot obtain this parallelism from his mechanics. He imagines that 

 if the globe of the earth move round the sun, and also round its own 

 axis, the axis of rotation must always preserve the same inclination 

 to the line joining the centre of the earth and sun : just as when a 

 ball fastened by a string is made to spin, and a conical motion is 

 simultaneously given to the string and ball. It is most evident that 

 he got this idea from the solid crystal spheres. If the earth's axis 

 were fixed in an immense sphere, with which it turned round the 

 sun, and if in the first instance the axis produced would pass through 

 the axis of the sphere, the complete phenomenon of Copernicus would 

 be produced. The earth's axis would then describe a cone yearly. 

 To produce parallelism, Copernicus imagines what we may call an 

 anticouical motion, namely, that the earth's axis is itself endued witli 

 such motion, independent of its motion in the sphere, as would, did 

 it act alone, carry the axis round the same cone in a year, but the 

 contrary way. The effect of the two motions is to destroy each other, 

 and the axis remains parallel in all its positions. Then, by supposing 

 the anticonical motion to be a little greater than the direct conical 

 motion, by 50" in a year, he produces the phenomenon of the pre- 

 cession of the equinoxes. If we consider that even Newton himself, 

 in tracing the effect of the forces which cause the precession, is thought 

 to have misconceived his own laws of motion, it is not at this part of 

 the mechanics of Copernicus that we need express surprise : and this 

 explanation of the cause of the seasons and of the precession, together 

 with that of the stations, &c.' of the plmets, must always place him 

 among cosmical discoverers of the first order of sagacity. 



All that we have hitherto described will explain the mean motions 

 of the solar system, and the mean motions only. To account for all 

 irregularities, Copernicus (hampered with the notion that all motions 

 must be compounded of circular ones) is obliged to introduce a 

 system of epicycles entirely resembling that of Ptoleuiteus. It will 

 surprise many readers to hear that the greater part of the work of 

 Copernicus is taken up with the description of this most essential 

 branch of the real ' Copernican system." But it must be added that 

 the Copernican epicycles are more successful than the Ptolemaic. 

 The latter were utterly uusullicieut as a means of demonstrating the 

 chanjes of distance of the planets and earth. The former, founded 

 upon a basis which brought this point not very far from the truth at 

 the outset, made a much nearer approximation to a correct repre- 

 sentation of the inequalities. But as the epicyclic system is not now 

 connected with the name of Copernicus, we need pursue this subject 

 no further, satisfied that what we have done will have a tendency to 

 put the reputation of that sagacious investigator in its proper place, 

 and that no mean one, though lower than the one usually assigned 

 to it. 



Of the tables of Copernicus, his trigonometrical formulae, &o., this 

 is not the place to apeak : they are more connected with the sciences 

 they belong to than with his biography. 



While Copernicus was in daily expectation of receiving a complete 

 copy of his work from Rheticua, he was seized with hemorrhage, 

 followed by paralysis. The book actually arrived May 23, 1543, and, 

 aa Qysius wrote to Rheticus, Copernicus saw it, and touched it, but 

 was too near his end to do more. He died in a few hours after, and 

 was buried in the cathedral to which he belonged. 



We copy the following references to sources of information from 

 the ' Bibliog. Astron." of Lalande, p. 595 ; Adam, ' Vitse Phil. Germ. ; ' 

 Tycho Brabe", ' Orat. de Math. ; ' Jovius, ' Elog. Doet. Vir. ; ' Bul- 

 lialdus, ' Proleg. Astr. Phil. ; ' Vossius, ' De Sci. Math. ; ' Crasso, 

 ' Elog. d'Uom. Letter. ; ' Ghilini, 'Teatro,' torn, it ; Frehrrus, torn. ii. ; 

 Blount, ' Cens. Cel. Auct ; ' Paschius, ' De Invent. Nov. Ant. ; ' ' Actu 

 Phil.,' part v., p. 884 ; Zernecke, ' Chronik von Thorn,' 2 ed., Berlin, 

 1727; 'Pantheon der Deutschen,' 1796; 'Berlin. Mouatschrifft,' 

 August 1792, March 1793; ' Preussische 8 Archiv.,' December 1796; 

 Wielaud, ' Teutacher Merkur,' November 1776. We may here notice 

 that Ghilini asserts an epistle ' De Motu Octaves Sphsorao ' to have 

 been printed ; but as Gasseudi had never seen it, and we can find no 

 mention of it, we conclude no such epistle was published, though one 

 with tha* name was certainly written. 



COPLESTON, REV. EDWARD, D.D., was born February 2, 1776, 

 at the rectory-house, Offwell, Devonshire. His father, the R.:v. John 

 Bradford Copleston, was the rector of that parish, and he educated at 

 h'n own residence a limited number of pupils, among whom was his 

 son Edward. In 1791 Edward Cohesion was elected to a scholarship 

 at Corpus Christi, Oxford; in 1793 he obtained the Chancellor's prize 

 : or a Latin poem ; and in 1795 he was elected a Fellow of Oriel College. 

 He obtained the Chancellor's prize for an English essay on ' Agricul- 

 ture' in 1796, and in 1797 was appointed college-tutor, though he bad 

 not then taken his degree of M.A. In 1802 he was elected Professor 

 of Poetry to the university, in which office he succeeded Dr. Hurdis. 

 tie published in 1813 the substance of the lectures which he had 

 delivered, under the title of ' Prselectioues Academiete,' a work which 

 gained him a high reputation for pure and elegant Latin composition 

 jombined with extensive poetical information. Some severe attack* 

 on the University of Oxford having been made in the ' Edinburgh 

 Review,' Mr. Copleston published in 1810 ' A Reply to the Calumnies 



