Online Encyclopedia

Search over 40,000 articles from the original, classic Encyclopedia Britannica, 11th Edition.

LEONARDO OF PISA (LEONARDUS PISANUS O...

Online Encyclopedia
Originally appearing in Volume V16, Page 455 of the 1911 Encyclopedia Britannica.
Spread the word: del.icio.us del.icio.us it!

LEONARDO OF See also:

PISA (LEONARDUS PISANUS Or FIBONACCI) , See also:Italian mathematician of the 13th See also:century. Of his See also:personal See also:history few particulars are known. His See also:father was called Bonaccio, most probably a See also:nickname with the ironical meaning of " a See also:good, stupid See also:fellow," while to Leonardo himself another nickname, Bigollone (See also:dunce, blockhead), seems to have been given. The father was secretary in one of the numerous factories erected on the See also:southern and eastern coasts of the Mediterranean by the warlike and enterprising merchants of Pisa. Leonardo was educated at Bugia, and afterwards toured the Mediterranean. In 1202 he was again in See also:Italy and published his See also:great See also:work, See also:Liber abaci, which probably procured him See also:access to the learned and refined See also:court of the See also:emperor See also:Frederick II. Leonardo certainly was in relation with some persons belonging to that circle when he published in 1220 another more extensive work, De practica geometriae, which he dedicated to the imperial astronomer Dominicus Hitipanus. Some years afterwards (perhaps in 1228) Leonardo dedicated to the well-known astrologer See also:Michael See also:Scott the second edition of his Liber abaci, which was printed with Leonardo's other See also:works by See also:Prince Bald. Boncompagni (See also:Rome, 1857–1862, 2 vols.). The other works consist of the Practica geometriae and some most striking papers of the greatest scientific importance, amongst which the Liber quadratorum may be specially signalized. It bears the See also:notice that the author wrote it in 1225, and in the introduction Leonardo tells us the occasion of its being written. Dominicus had presented Leonardo to Frederick II.

The presentation was accompanied by a See also:

kind of mathematical performance, in which Leonardo solved several hard problems proposed to him by See also:John of See also:Palermo, an imperial See also:notary, whose name is met with in several documents dated between 1221 and 124o. The methods which Leonardo made use of in solving those problems fill the Liber quadratorum, the Flos, and a See also:Letter to Magisler See also:Theodore. All these See also:treatises seem to have been written nearly at the same See also:period, and certainly before the publication of the second edition of the Liber abaci, in which the Liber quadratorum is expressly mentioned. We know nothing of Leonardo's See also:fate after he issued that second edition. Leonardo's works are mainly developments of the results obtained by his predecessors; the influences of See also:Greek, Arabian, and See also:Indian mathematicians may be clearly discerned in his methods. In his Practica geometriae See also:plain traces of the use of the See also:Roman agrimensores are met with; in his Liber abaci old See also:Egyptian problems reveal their origin by the reappearance of the very See also:numbers in which the problem is given, though one cannot guess through what channel they came to Leonardo's knowledge. Leonardo cannot be regarded as the inventor of that very great variety of truths for which he mentions no earlier source. The Liber abaci, which fills 459 printed pages, contains the most perfect methods of calculating with whole numbers and with fractions, practice, extraction of the square and See also:cube roots, proportion, See also:chain See also:rule, finding of proportional parts, averages, progressions, even See also:compound See also:interest, just as in the completest See also:mercantile arithmetics of our days. They See also:teach further the See also:solution of problems leading to equations of the first and second degree, to determinate and indeterminate equations, not by single and See also:double position only, but by real See also:algebra, proved by means of geometric constructions, and including the use of letters as symbols for known numbers, the unknown quantity being called res and its square See also:census. The second work of Leonardo, his Practica geometriae (1220) See also:strategy, but his heroism and devotion secured him an almost unique See also:place in the See also:imagination not only of his own but also of succeeding times. See See also:Herodotus v. 39-41, vii.

202-225, 238, ix. 10; Diodorus xi. 4-I1; See also:

Plutarch, See also:Apophthegm. Lacon.; de malignitate Herodoti, 28-33; See also:Pausanias i. 13, iii. 3, 4; Isocrates, Paneg. 92; See also:Lycurgus, c. Leocr. 11o, III; See also:Strabo i. 1o, ix. 429; See also:Aelian, See also:Var hist. iii. 25; See also:Cicero, Tusc. disput. i.

42, 49; de Finibus, ii. 30; See also:

Cornelius See also:Nepos, See also:Themistocles, 3; See also:Valerius See also:Maximus iii. 2; See also:Justin ii. II. For See also:modern See also:criticism on the See also:battle of See also:Thermopylae see G. B. See also:Grundy, The Great See also:Persian See also:War (1901); G. See also:Grote, History of See also:Greece, See also:part ii., c: 40; E. See also:Meyer, Geschichte See also:des A'tertums, iii., §§ 219, 220; G. Busolt, Griechische Geschichte, 2nd ed., ii. 666-688; J. B.

See also:

Bury, " The See also:Campaign of Artemisium and Thermopylae," in See also:British School See also:Annual, ii. 83 seq.; J. A. R. See also:Munro, " Some Observations on the Persian See also:Wars, II.," in See also:Journal of Hellenic Studies, xxii. 294-332. (M. N.

End of Article: LEONARDO OF PISA (LEONARDUS PISANUS Or FIBONACCI)

Additional information and Comments

There are no comments yet for this article.
» Add information or comments to this article.
Please link directly to this article:
Highlight the code below, right click, and select "copy." Then paste it into your website, email, or other HTML.
Site content, images, and layout Copyright © 2006 - Net Industries, worldwide.
Do not copy, download, transfer, or otherwise replicate the site content in whole or in part.

Links to articles and home page are always encouraged.

[back]
LEONARDO DA VINCI, 159
[next]
LEONCAVALLO, RUGGIERO (1858– )