- Johannes Campanus
Johannes Campanus (in Italian, Giovanni Campano; also known as Campanus of Novara or similar) (1220-1296) was an Italian
astrologer ,astronomer , andmathematician who devised a house system for thehoroscope which bears his name. This house system divides theprime vertical into equal 30° arcs, or houses.Born in
Novara , he served as chaplain toPope Urban IV and personal physician toPope Boniface VIII . He travelled toArabia andSpain .In 1260, Campanus published a
Latin edition of Euclid's "Elementa geometriae", in fifteen books. The work was based on anArabic translation of the original Greek text. Campanus probably also had access to the Latin translation of Euclid's work executed around 1120 byAdelard of Bath . It was used for two centuries and was printed inVenice in 1482 as "Preclarissimus liber elementorum Euclidis".In the field of astronomy, he wrote a "Theorica Planetarum" in which he geometrically described the motions of the
planet s as well as theirlongitude . He also included instructions on building aplanetarium as well as its geometrical description. This was the first description of a planetarium by a European. Campanus also attempted to determine the time of each planet'sretrograde motion . The data on planets are drawn from the "Almagest " and the "Toledan Tables " of the Arab astronomerArzachel . Campanus gave precise instructions on using the tables, and made detailed calculations of the distances to the planets and their sizes.Campanus also wrote "Tractatus de Sphaera", "De computo ecclesiastico" and "Calendarium".
His "De computo ecclesiastico" or "Computus maior" (ca. 1261-ca. 1264) was written by Campanus for
Pope Urban VI does not make any reference to amechanical clock , thereby leading historians to believe that the clock was not invented until 1280 or so. [http://www.clockmakersgallery.com/history.html]His contemporary
Roger Bacon cited Campanus as one of the great mathematicians of the age.He died at
Viterbo .Campanus crater, on the
Moon , is named after him.Sources
* [http://www-gap.dcs.st-and.ac.uk/~history/Mathematicians/Campanus.html Campanus of Novara]
* [http://www.polybiblio.com/watbooks/2423.html W.P. Watson Books]
* [http://www.clockmakersgallery.com/history.html Clockmakers' Gallery]
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