Gemma Frisius, seventeenth-century woodcut by E. de Boulonois

For the crater, see Gemma Frisius (crater)

Gemma Frisius (or Reiner Gemma, December 9, 1508 - May 25, 1555) was a mathematician, cartographer and instrument maker. He created important globes, improved the mathematical instruments of his day and applied mathematics in new ways to surveying and navigation. Gemma Frisius, woodcut by E. de Boulonois (fl. ... Gemma Frisius is a lunar crater that is located in the rugged southern highlands of the Moon. ... December 9 is the 343rd day (344th in leap years) of the year in the Gregorian calendar. ... 1508 was a leap year starting on Wednesday (see link for calendar) of the Gregorian calendar. ... May 25 is the 145th day of the year in the Gregorian calendar (146th in leap years). ... Events Russia breaks 60 year old truce with Sweden by attacking Finland February 2 - Diet of Augsburg begins February 4 - John Rogers becomes first Protestant martyr in England February 9 - Bishop of Gloucester John Hooper is burned at the stake May 23 - Paul IV becomes Pope. ... Mathematics is often defined as the study of topics such as quantity, structure, space, and change. ... Cartography or mapmaking (in Greek chartis = map and graphein = write) is the study and practice of making maps or globes. ... A globe This article is on a planet model. ...

He was born in Dokkum, Friesland (present-day Netherlands) of poor parents, who died when he was young. Though a poor orphan, he studied at Leuven beginning in 1525. He received the degree of MD in 1536 and remained on the faculty of medicine at Leuven for the rest of his life. Dongeradeel is a municipality in the northern Netherlands. ... Fryslân province Frisian cattle The Frisian flag (water lily leaves on water) Friesland is a province in the north of the Netherlands. ... The Katholieke Universiteit Leuven (or K.U.Leuven, or in English Catholic University of Leuven - also the translated name of its French-speaking sister university) - is a Flemish university, located in the town of Leuven in Flanders, the Dutch-speaking (northern) region of Belgium. ... Events January 21 - The Swiss Anabaptist Movement was born when Conrad Grebel, Felix Manz, George Blaurock, and about a dozen others baptized each other in the home of Manzs mother on Neustadt-Gasse, Zürich, breaking a thousand-year tradition of church-state union. ... Events February 2 - Spaniard Pedro de Mendoza founds Buenos Aires, Argentina. ...

While still a student, Frisius set up a workshop to produce globes and mathematical instruments. He became noted for the quality and accuracy of his instruments, which were praised by Tycho Brahe, among others. In 1533, he described for the first time the method of triangulation still used today in surveying. Twenty years later, he was the first to describe how an accurate clock could be used to determine longitude. Frisius created or improved many instruments, including the cross-staff, the astrolabe and the astronomical rings. His students included Gerardus Mercator (who became his collaborator), Johannes Stadius, and John Dee. Tycho Brahe Tycho Brahe, born Tyge Ottesen Brahe (December 14, 1546 – October 24, 1601), was a Danish nobleman astronomer as well as an astrologer and alchemist. ... Events January 25 - King Henry VIII of England marries Anne Boleyn, his second Queen consort. ... Map of Earth showing lines of longitude, which appear curved and vertical in this projection, but are actually halves of great circles Longitude, sometimes denoted by the Greek letter λ, describes the location of a place on Earth east or west of a north-south line called the Prime Meridian. ... A 16th century astrolabe. ... Gerardus Mercator (March 5, 1512 – December 2, 1594) was a Flemish cartographer of Dutch descent, remembered for the Mercator projection named after him. ... For the crater, see Stadius (crater). ... A sixteenth century portrait of John Dee, artist unknown. ...

External links

• Regnier Gemma Frisius from University of St Andrews School of Mathematics and Statistics.