Editing Gerardus Mercator (section)

{{Short description|Flemish cartographer (1512–1594)}}
{{good article}}
{{pp-move|small=yes}}
{{Use dmy dates|date=March 2023}}
{{Infobox scientist
| name        = Gerardus Mercator
| image       = Gerardo Mercatore - Gerardus Mercator.jpg
| image_size  = 230px
| caption     = Portrait by Hogenberg,1574.  [[#portrait|(Translation)]]
| alt         = Portrait of Gerard Mercator
| birth_name  = Geert De Kremer
| birth_date  = 5 March 1512
| birth_place = [[Rupelmonde]], [[County of Flanders]]
| death_date  = {{Death date and age|df=yes|1594|12|2|1512|3|5}}
| death_place = [[Duisburg]], [[United Duchies of Jülich-Cleves-Berg]], {{avoid wrap|Holy Roman Empire}}
| monuments   =
| nationality = 
| other_names = 
| education   = [[Old University of Leuven|University of Leuven]]
| known_for   = {{Plainlist|
* [[Mercator 1569 world map|World map]] based on the [[Mercator projection]] (1569)
* Coining the term [[Atlas]]
}}
| spouse      = {{plainlist|
* {{marriage|Barbara Schellekens|1534|1586|end=d}}
* {{marriage|Gertrude Vierlings|1589}}
}}
| children    = 6, including [[Arnold Mercator|Arnold]] and [[Rumold Mercator|Rumold]]
| signature   = Signature of Gerardus Mercator (1512–1594).png 
}}
'''Gerardus Mercator''' ({{IPAc-en|dʒ|ɪ|ˈ|r|ɑːr|d|ə|s|_|m|ɜr|ˈ|k|eɪ|t|ər}};{{efn| name=dictionary.com}}{{efn|name=pronumciation1}}{{efn|name=pronumciation2}} 5 March 1512 – 2 December 1594){{efn|name=birthdeathdates}} was a [[Flemish people|Flemish]] [[geographer]], [[cosmographer]] and [[Cartography|cartographer]]. He is most renowned for creating the [[Mercator 1569 world map|1569 world map]] based on a new [[Mercator projection|projection]] which represented sailing courses of constant bearing ([[rhumb line]]s) as straight lines—an innovation that is still employed in nautical charts.

Mercator was a notable maker of globes and scientific instruments. In addition, he had interests in theology, philosophy, history, mathematics, and [[geomagnetism]]. He was also an accomplished [[engraving|engraver]] and [[Calligraphy|calligrapher]]. Unlike other great scholars of the age, he travelled little and his knowledge of geography came from his library of over a thousand books and maps, from his visitors and from his vast correspondence (in six languages) with other scholars, statesmen, travellers, merchants and seamen. Mercator's early maps were in large formats suitable for wall mounting but in the second half of his life, he produced over 100 new regional maps in a smaller format suitable for binding into his [[Atlas]] of 1595. This was the first appearance of the word Atlas in reference to a book of maps. However, Mercator used it as a neologism for a treatise (''Cosmologia'') on the creation, history and description of the universe, not simply a collection of maps. He chose the word as a commemoration of the [[Atlas (mythology)|Titan Atlas]], "King of Mauretania", whom he considered to be the first great geographer.

A large part of Mercator's income came from sales of terrestrial and [[celestial globe]]s. For sixty years they were considered the finest in the world, and were sold in such numbers that there are many surviving examples. This was a substantial enterprise involving the manufacture of the spheres, printing the [[Globe#Manufacture|gores]], building substantial stands, packing and distributing them all over Europe. He was also renowned for his scientific instruments, particularly his [[astrolabe]]s and [[astronomical rings]] used to study the [[geometry]] of [[astronomy]] and [[astrology]].

Mercator wrote on geography, philosophy, [[chronology]] and theology. All of the wall maps were engraved with copious text on the region concerned. As an example, the famous world map of 1569 is inscribed with over five thousand words in [[Mercator 1569 world map#Summary of the legends|fifteen legends]]. The 1595 Atlas has about 120 pages of maps and illustrated title pages, but a greater number of pages are devoted to his account of the creation of the [[universe]] and descriptions of all the countries portrayed. His table of chronology ran to some 400 pages fixing the dates (from the time of [[Creationism|creation]]) of earthly [[Dynasty|dynasties]], major political and military events, [[volcanic eruption]]s, earthquakes and [[eclipse]]s. He also wrote on the [[gospel]]s and the [[Old Testament]].

Mercator was a devout [[Christians|Christian]] born into a [[Catholic Church|Catholic]] family at a time when [[Martin Luther]]'s [[Protestantism]] was gaining ground. He never declared himself as a [[Lutheranism|Lutheran]] but was clearly sympathetic, and he was accused of heresy by Catholic authorities; after six months in prison he was released unscathed. This period of persecution is probably the major factor in his move from Catholic [[Leuven]] (Louvain) to a more tolerant [[Duisburg]], in the Holy Roman Empire, where he lived for the last thirty years of his life. Walter Ghim, Mercator's friend and first biographer, describes him as sober in his behaviour, yet cheerful and witty in company, and never more happy than in debate with other scholars.{{efn|The full text of Ghim's biography is translated in {{harvtxt|Sullivan|2000}} pages 7–24 of the atlas text, pdf pages 77–94.}}