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APOLLONIUS OF PERGA [PERGAEUS]

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Originally appearing in Volume V02, Page 188 of the 1911 Encyclopedia Britannica.
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APOLLONIUS OF See also:PERGA [PERGAEUS] , See also:Greek geometer of the Alexandrian school, was probably See also:born some twenty-five years later than See also:Archimedes, i.e. about 262 B.C. He flourished in the reigns of See also:Ptolemy Euergetes and Ptolemy Philopator (247—205 B.C.). His See also:treatise on Conics gained him the See also:title of The See also:Great Geometer, and is that by which his fame has been transmitted to See also:modern times. All his numerous other See also:treatises have perished, See also:save one, and we have only their titles handed down, with See also:general indications of their contents, by later. writers, especially Pappus. After the Conics in eight Books had been written in a first edition, Apollonius brought out a second edition, considerably revised as regards Books i.-ii., at the instance of one Eudemus of See also:Pergamum; the first three books were sent to Eudemus at intervals, as revised, and the later books were dedicated (after Eudemus' See also:death) to See also:King Attalus I. (241–197 B.C.). Only four Books have survived in Greek; three more are extant in Arabic; the eighth has never been found. Although a fragment has been found of a Latin See also:translation from the Arabic made in the 13th See also:century, it was not until 1661 that a Latin translation of Books v.-vii. was available. This was made by Giovanni Alfonso See also:Borelli and See also:Abraham See also:Ecchellensis from the See also:free version in Arabic made in 983 by See also:Abu '1-Fath of Ispahan and preserved in a See also:Florence MS. But the best Arabic translation is that made as regards Books i.-iv. by Hilal See also:ibn Abi Hilal (d. about 883), and as regards Books v.-vii. by See also:Tobit See also:ben Korra (836–901). See also:Halley used for his translation an See also:Oxford MS. of this translation of Books v.-vii., but the best MS. (Bodl.

943) he only referred to in See also:

order to correct his translation, and it is still unpublished except for a fragment of See also:Book v. published by L. Nix with See also:German translation (Drugulin, See also:Leipzig, 1889). Halley added in his edition (1710) a restoration of Book viii., in which he was guided by the fact that Pappus gives lemmas " to the seventh and eighth books " under that one heading, as well as by the statement of Apollonius himself that the use of the seventh book was illustrated by the problems solved in the eighth. The degree of originality of the Conics can best be judged from Apollonius' own prefaces. Books i.-iv. See also:form an " elementary introduction," i.e. contain the essential principles; the See also:rest are specialized investigations in particular directions. For Books i.-iv. he claims only that the See also:generation of the curves and their fundamental properties in Book i. are worked out more fully and generally than they were in earlier treatises, and that a number of theorems in Book iii. and the greater See also:part of Book iv. are new. That he made the fullest use of his predecessors' See also:works, such as See also:Euclid's four Books on Conics, is clear from his allusions to Euclid, See also:Conon and Nicoteles. The generality of treatment is indeed remarkable; he gives as the fundamental See also:property of all the conics the See also:equivalent of the Cartesian See also:equation referred to oblique axes (consisting of a See also:diameter and the tangent at its extremity) obtained by cutting an oblique circular See also:cone in any manner, and the axes appear only as a particular See also:case after he has shown that the property of the conic can be expressed in the same form with reference to any new diameter and the tangent at its extremity. It is clearly the form of the fundamental property (expressed in the terminology of the " application of areas ") which led him to See also:call the curves for the first See also:time by the names See also:parabola, See also:ellipse, See also:hyperbola. Books v.-vii. are clearly See also:original. Apollonius' See also:genius takes its highest See also:flight in Book v., where he treats of normals as minimum and maximum straight lines See also:drawn from given points to the See also:curve (independently of tangent properties), discusses how many normals can be drawn from particular points, finds their feet by construction, and gives propositions determining the centre of curvature at any point and leading at once to the Cartesian equation of the evolute of any conic. The other treatises of Apollonius mentioned by Pappus are -1st, AOyov aaoro a', Cutting off a Ratio; 2nd, Xwplou airoroµil, Cutting off an See also:Area; 3rd, t.twplvpEVq ropil, Determinate See also:Section; 4th,'Eira¢ai, Tangencies; 5th, See also:Nebo-es, Inclinations; 6th, Tolroi E7rl7rEb01, See also:Plane Loci.

Each of these was divided into two books, and, with the Data, the Porisms and See also:

Surface-Loci of Euclid and the Conics of Apollonius were, according to Pappus, included in the See also:body of the See also:ancient See also:analysis. 1st. De Rationis Sectione had for its subject the See also:resolution of the following problem: Given two straight lines and a point in each, to draw through a third given point a straight See also:line cutting the two fixed lines, so that the parts intercepted between the given points in them and the points of intersection with this third line may have a given ratio. 2nd. De Spatii Sectione discussed the similar problem which requires the rectangle contained by the two intercepts to be equal to a given rectangle. An Arabic version of the first was found towards the end of the 17th century in the Bodleian library by Dr See also:Edward See also:Bernard,.187 who began a translation of it; Halley finished it and published it along with a restoration of the second treatise in r7o6. 3rd. De Sectione Determinata resolved the problem: Given two, three or four points on a straight line, to find another point on it such that its distances from the given points satisfy the See also:condition that the square on one or the rectangle contained by two has to the square on the remaining one or the rectangle contained by the remaining two, or to the rectangle contained by the remaining one and another given straight line, a given ratio. Several restorations of the See also:solution have been attempted, one by W. Snellius (See also:Leiden, 1698), another by Alex. See also:Anderson of See also:Aberdeen, in the supplement to his Apollonius Redivivus (See also:Paris, 1622), but by far the best is by See also:Robert See also:Simson, See also:Opera quaedam reliqua (See also:Glasgow, 1776). 4th.

De Tactionibus embraced the following general problem: Given three things (points, straight lines or circles) in position, to describe a circle passing through the given points, and touching the given straight lines or circles. The most difficult case, and the most interesting from its See also:

historical associations, is when the three given things are circles. This problem, which is sometimes known as the Apollonian Problem, was proposed by See also:Vieta in the 16th century to Adrianus See also:Romanus, who gave a solution by means of a hyperbola. Vieta thereupon proposed a simpler construction, and restored the whole treatise of Apollonius in a small See also:work, which he entitled Apollonius See also:Gallus (Paris, 2600). A very full and interesting historical See also:account of the problem is given in the See also:preface to a small work of J. W. Camerer, entitled A pollonii Pergaei quae supersunt, ac maxime Lemmata Pappi in hos Libros, cum Observationibus, &c. (Gothae, 1795, 8vo). 5th. De Inclinationibus had for its See also:object to insert a straight line of a given length, tending towards a given point, between two given (straight or circular) lines. Restorations have been given by See also:Marino Ghetaldi, by See also:Hugo d'Omerique (Geometrical Analysis, See also:Cadiz, 2698), and (the best) by See also:Samuel See also:Horsley (1770). 6th.

De Locis Planis is a collection of propositions See also:

relating to loci 'which are either straight lines or circles. Pappus gives somewhat full particulars of the propositions, and restorations were attempted by P. See also:Fermat (Euvres, i., 2891, pp. 3-51), F. Schooten (Leiden,. 1656) and, most successfully of all, by R. Simson (Glasgow, 1749). Other works of Apollonius are referred to by ancient writers, viz. (1) HEpi Tor) 7rvplou, On the Burning-See also:Glass, where the See also:focal properties of the parabola probably found a See also:place; (2) Hepi rout Koxkiov, On the Cylindrical See also:Helix (mentioned by See also:Proclus); (3) a comparison of the See also:dodecahedron and the See also:icosahedron inscribed in the same See also:sphere; (4) `H KaObXou 7rpay sareia, perhaps a work on the general principles of See also:mathematics in which were included Apollonius' criticisms and suggestions for the improvement of Euclid's Elements; (5) 'Slevrbi ov (See also:quick bringing-to-See also:birth), in which, according to Eutocius, he showed how to find closer limits for the value of it than the 3 7 and 3+7- of Archimedes; (6) an arithmetical work (as to which see PAPPUS) on a See also:system of expressing large See also:numbers in See also:language closer to that of See also:common See also:life than that of Archimedes' See also:Sand-reckoner, and showing how to multiply such large numbers; (7) a great See also:extension of the theory of irrationals expounded in Euclid, Book x., from See also:binomial to multinomial and from ordered to unordered irrationals (see extracts from Pappus' See also:comm. on Eucl. x., preserved in Arabic and published by Woepcke, 1856). Lastly, in See also:astronomy he is 'credited by Ptolemy with an explanation of the See also:motion of the See also:planets by a. system of epicycles; he also made researches in the lunar theory, for which he is said to have been called Epsilon (E). The best See also:editions of the works of Apollonius are the following : (I) Apollonii Pergaei Conicorum libri quatuor, ex version Frederici Commandini (Bononiae, 1566), fol. ;.

(2) A pollonii Pergaei Conicorum libri octo, et Sereni Antissensis de Sectione Cylindri et Coni libri duo (Oxoniae, 171o), fol. (this is the monumental edition of See also:

Edmund Halley) ; (3) the edition of the first four books of the Conics given in 1675 by See also:Barrow; (4) Apollonii Pergaei de Sectione Rationis libri duo: Accedunt ejusdem de Sectione Spatii libri duo Restituti: Praemittitur, &c., Opera et Studio Edmundi Halley (Oxoniae, 1706), 4to; (5) a German translation of the Conics by H. See also:Balsam (See also:Berlin, 1861); (6) the definitive Greek See also:text of See also:Heiberg (A pollonii Pergaeiquae Graece exstant Opera, Leipzig, 1891–1893); (7) T. L. See also:Heath, Apollonius, Treatise on Conic Sections (See also:Cambridge, 1896) ; see also H. G. Zeuthen, See also:Die Lehre von den Kegelschnitten See also:im Altertum (See also:Copenhagen, 1886 and 1902). (T. L.

End of Article: APOLLONIUS OF PERGA [PERGAEUS]

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