1691 Sanson Map of the World on Hemisphere Projection - Geographicus - World-sanson-1691

The history of French cartography can be traced to developments in the Middle Ages. This period was marked by improvements in measuring instruments and also by an upgrade of work in registers of all types. What is thought to be the oldest land map in Europe, the Saint-Bélec slab, representing an area of the Odet valley, was found in 1900, and rediscovered in a castle cellar in France in 2014. The Bronze-Age stone is thought to be 4,000-years old. The first map of France was drawn by Oronce Finé and printed in woodcuts in 1525. It testifies to the will of the political power to mark its presence on the territory; to affirm, to build limits, borders, to arrange its territory, and to consolidate the internal economic markets. In the 16th century, Dieppe appeared as an important school of cartography.

Pierre Desceliers Pierre Desceliers ( 1537–1553) was a French cartographer of the Renaissance and an eminent member of the Dieppe School of Cartography. He is considered the father of French hydrography. Little is known of his life. He was probably born at Arq ...

allowed the realization of many maps. At the same time, the

Portolan map Portolan charts are nautical charts, first made in the 13th century in the Mediterranean Sea, Mediterranean basin and later expanded to include other regions. The word ''portolan'' comes from the Italian language, Italian ''portulano'', meaning " ...

s of the Portuguese sailors had the most recent knowledge obtained by the Dieppois sailors in their exploration of Canada. Developments in cartography continually progressed, through new techniques and by the expanding will of political powers to amass and control territories. Very powerful companies testify support to some of the cartographic missions at the end of the 19th century. Two major milestones in cartographic study was of determining longitude and latitude.

Cassini maps

In France, the first general maps of the territory using a measuring apparatus were made by the Cassini family during the 18th century on a scale of 1:86,400 (one centimeter on the chart corresponds to approximately 864 meters on the ground). The map of Cassini is the first geometrical map covering the entire kingdom of France. Before the surveys, it was necessary to carry out a triangulation of the territory. These maps were, for their time, a technical innovation. They were the first maps based on geodetic

triangulation In trigonometry and geometry, triangulation is the process of determining the location of a point by forming triangles to the point from known points. Applications In surveying Specifically in surveying, triangulation involves only angle me ...

, and took more than fifty years to complete; four generations of the Cassini family were involved in their production. These maps, known as "Cassini Maps" or "maps of the Academy," are still referenced by geographers, historians and genealogists. The work of the Cassinis left its mark on the world; toponyms known as "Cassini signs" still exist, revealing where triangulated measurements at that time were made. The "map of Cassini" or "map of the Academy" is the first general map of the kingdom of France. It was drawn up by the Cassini family—primarily

César-François Cassini de Thury César-François Cassini de Thury (17 June 1714 – 4 September 1784), also called Cassini III or Cassini de Thury, was a French astronomer and cartographer. Biography Cassini de Thury was born in Thury-sous-Clermont, in the Oise departme ...

(Cassini III) and his son Jean-Dominique Cassini (Cassini IV)—during the 18th century. The adopted scale is one ligne to 100 toises, or 1:86,400 (the measuring apparatus contained 864 lines). The map does not pinpoint dwellings or the boundaries of marshes and forests; however, the level of precision of the road networks is such that satellite photographs correspond almost completely with drawn roads more than 200 years later. This map is still consulted today by researchers. It interests historians, in particular those in the fields of geography, genealogy and ecology.

Purpose

César-François Cassini (Cassini III) began the map: * To measure distances by triangulation, ensuring the exact positioning of locations * To measure the kingdom, determining the number of boroughs, cities and villages * To depict unchanging landscape features

Survey maps

The surveys were carried out between 1756 and 1789 and the 181 sheets composing the map were published from 1756 to 1815. César-François Cassini died in 1784 with his work unfinished. His son, Jean-Dominique Cassini (1748–1845), later finished the work of his father. The departments of

Savoy Savoy (; frp, Savouè ; french: Savoie ) is a cultural-historical region in the Western Alps. Situated on the cultural boundary between Occitania and Piedmont, the area extends from Lake Geneva in the north to the Dauphiné in the south. Savo ...

, Haute-Savoie and part of the

Maritime Alps The Maritime Alps (french: Alpes Maritimes ; it, Alpi Marittime ) are a mountain range in the southwestern part of the Alps. They form the border between the regions of France, French region of Provence-Alpes-Côte d'Azur and the regions of Italy ...

were not part of the Kingdom of France at the time, and are not represented on the map; neither are the Île d'Yeu and

Corsica Corsica ( , Upper , Southern ; it, Corsica; ; french: Corse ; lij, Còrsega; sc, Còssiga) is an island in the Mediterranean Sea and one of the 18 regions of France. It is the fourth-largest island in the Mediterranean and lies southeast of ...

. Most of the map sheets were published as a new edition in 1815.

Replacement by Napoleon I

In 1808,

Napoleon I Napoleon Bonaparte ; it, Napoleone Bonaparte, ; co, Napulione Buonaparte. (born Napoleone Buonaparte; 15 August 1769 – 5 May 1821), later known by his regnal name Napoleon I, was a French military commander and political leader who ...

decided to produce a map intended to be more accurate than that of Cassini. However, Napoleon demanded that the primary goal of the work was to produce battlefield maps. The triangulation for this new map began also from the

Paris meridian The Paris meridian is a meridian line running through the Paris Observatory in Paris, France – now longitude 2°20′14.02500″ East. It was a long-standing rival to the Greenwich meridian as the prime meridian of the world. The "Paris merid ...

arc or French meridian line (French: Méridienne de France) surveyed this time by

Delambre Jean Baptiste Joseph, chevalier Delambre (19 September 1749 – 19 August 1822) was a French mathematician, astronomer, historian of astronomy, and geodesist. He was also director of the Paris Observatory, and author of well-known books on th ...

and Méchain (the

meridian arc of Delambre and Méchain Meridian or a meridian line (from Latin ''meridies'' via Old French ''meridiane'', meaning “midday”) may refer to Science * Meridian (astronomy), imaginary circle in a plane perpendicular to the planes of the celestial equator and horizon * ...

). Work on this map took place between 1817 and 1866. During this period several different scales were tested, with the scale 1:80,000 being chosen. This became known as the "Geological Survey" map. The funding for this work was provided by the Department of War. The first work was done by the ''Dépôt de la guerre'', and later by the Geographical Service of the Army, whose first director General François Perrier and his successor General Bassot remeasured the French

meridian arc In geodesy and navigation, a meridian arc is the curve between two points on the Earth's surface having the same longitude. The term may refer either to a segment of the meridian, or to its length. The purpose of measuring meridian arcs is to de ...

. It was originally produced as a mosaic of maps, pasted to fabric, folded and protected by a hard case. This allowed it to be transported with the army, and to survive the rigors of ground combat. At the beginning of the First World War (1914–1918), the difficulties of reading a map on this scale led the generals to request new map drawn to the 1:50 000 scale. This was more convenient, and practical, since one metre on the map equaled 50 kilometres. These new maps formed the basis for the current "Map of Excursion", which is at a scale of 1:25,000.

IGN

The Institut Géographique National (English: National Geographic Institute) or IGN is a French public state administrative establishment founded in 1940 to produce and maintain geographical information for France and its overseas departments and territories. “Intense cartographic work planned for the beginning of the war was stopped by the defeat of France in June 1940. Shortly afterward the great map service known to the world as the

Service Géographique de l’Armée Française Service may refer to: Activities * Administrative service, a required part of the workload of university faculty * Civil service, the body of employees of a government * Community service, volunteer service for the benefit of a community or a p ...

was demilitarized and renamed Institut National Géographique. Under this label, which it still bears, it continued to function, its activities including the opening of a new school for cartographers in the famous building of the

Hotel de Rohan A hotel is an establishment that provides paid lodging on a short-term basis. Facilities provided inside a hotel room may range from a modest-quality mattress in a small room to large suites with bigger, higher-quality beds, a dresser, a re ...

in Paris. A few more sheets of the 1:50,000 map of France were published. The main progress was achieved by the

African Army Map Service African or Africans may refer to: * Anything from or pertaining to the continent of Africa: ** People who are native to Africa, descendants of natives of Africa, or individuals who trace their ancestry to indigenous inhabitants of Africa *** Ethn ...

, which was able to pursue field work, particularly in the

Sahara , photo = Sahara real color.jpg , photo_caption = The Sahara taken by Apollo 17 astronauts, 1972 , map = , map_image = , location = , country = , country1 = , ...

. The list of maps of French Africa have lengthened notably."Gottman, Jean. 1946. “French Geography in Wartime.” The Geographical Review. Volume 36, 1946. Page 89.

References

IGN France International Created in 1986, IGN FI is the private subsidiary of the French Institut Géographique National (IGN) and works essentially abroad. Its goal is to promote the savoir-faire of the French IGN around the world. A company specialising in geographic ...

*
site about the B-17s of IGN
{{DEFAULTSORT:French Cartography Cartography by country Science and technology in France

Cassini maps

Purpose

Survey maps

Replacement by Napoleon I

IGN

See also

References

Further reading

External links