Regnier Gemma Frisius – mathematician, physician, geographer, astronomer, maker of maps, globes and scientific instruments – is one of the most important figures in the history of European cartography.
Born in Friesland (from which he took his surname), a coastal province in northern Netherlands, Frisius lost both his impoverished parents in early childhood and his upbringing fell to his stepmother, who had survived his father. Born crippled, then orphaned, his prospects in life were not promising, but his stepmother did her best to care for him and on a special feast day took the boy to the Catholic shrine of St. Boniface. The shrine was said to be a miracle-working site and following this visit the boy's condition did seem to improve, he became stronger and soon was able to walk on legs which formerly had not supported his body. Despite the improvement to his health, Frisius' health was to be frail throughout his life.
Notwithstanding his impoverished background, Frisius was able to obtain a brilliant education, matriculating in 1526 as a ‘poor student’ at the prestigious University of Louvain, where his primary studies were in medicine. On completing his degree, he worked as a physician in the city while continuing his studies at the university in mathematics and astronomy. In time he became a professor at Louvain University in medicine, mathematics, astronomy and geography, and came to be considered one of the leading theoretical mathematicians of his day. His knowledge of math and his work in astronomy resulted in the development of scientific instruments such as ‘Gemma’s rings’, which were used for sundials or planetariums, and other early astronomical instruments, and in the refinement and/or improvement of existing instruments, including many sophisticated variations of the astrolabe.
Frisius’ accomplishments are innumerable and many of his contributions to math and science are of import to this day. He reintroduced the idea of the camera obscura, and used his drawing of it (extant, and one of the first to be published) to demonstrate how he studied the eclipse of the sun on 24 January 1544. He introduced the idea of triangulation, which is still used today in the science of surveying, and he was the first to describe determining longitude with a clock. Precisely, he theorized in explicit terms that the use of high quality portable time markers could accurately measure longitude according to the time lapse between two points. This theory was mocked by many learned men, but finally proven two hundred years later when John Harrison devised the first accurate marine chronometer.
One of Frisius’ most important professors at university was Franciscan monk Franciscus Monachus. Well-known for a globe he constructed and for his dangerously unorthodox cartographic views, views which could easily have resulted in charges of heresy against him. Indeed, the earliest known published example of the earth depicted as a globe in two hemispheres was created by him for his geographical treatise, which is also one of the first to refer to a southern continent – terra australis. His influence on Frisius was profound and eventually under the monk’s guidance Frisius set up his own workshop in which were produced globes, maps and myriad mathematical instruments. His work was of such quality as to meet the high standards of contemporary men of learning such as the brilliant Tycho Brahe, himself a maker of sophisticated scientific instruments. This acclaim brought men of science from myriad places to the workshop of Regnier Gemma Frisius, in order to purchase the finest and latest models of European scientific instruments.
In time, Gerard Mercator came to study mathematics with Frisius (one of many well-known academics who studied with him), and together the two made a number of globes, one of which is in the National Maritime Museum in London, dated 1536, made in Louvain when both men were in their twenties. Aside from these, Frisius is known to have made other globes which do not survive. His maps are perhaps best represented in the maps published by Petrus Apianus in his Cosmographis, the majority of which are based directly on original works by Frisius himself, and Frisius did much of the editing for Apianus’ Cosmographia. From his student years on he made and recorded astronomical observations which were so accurate that in his honour there is a lunar crater named for him.
Despite his short life, Regnier Gemma Frisius’ impact on the developing science of cartography and our understanding in the realms of cosmography and geography cannot be overstated. His contributions were an integral and essential part of the scientific revolution which was redefining and reshaping man’s perception of the world.