French cartography

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.

The first map of France was drawn by Oronce Finé and printed in woodcuts in 1525.[1] 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 sixteenth century, Dieppe appeared as an important school of cartography. Pierre Desceliers allowed the realization of many maps. At the same time, the Portolan maps of the Portuguese sailors had the most recent knowledge obtained by the Dieppois sailors in their exploration of Canada.

Then, cartography progressed more and more, through the development of new techniques and by the will of the political powers to control their territories. Very powerful companies testify support to some of the cartographic missions at the end of the nineteenth century.

There were two decisive stages in cartography. One was determining longitude and latitude. Florence Trystram, 2001, the lawsuit of the stars is an account of the research of three French scientists that was done in South America, 1735-1771.

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). These maps were, for their time, a technical innovation. They were the first maps based on geodetic triangulation, 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 (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.


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.


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, Haute-Savoie and part of the Maritime Alps 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. Most of the map sheets were published as a new edition in 1815.

Replacement by Napoleon I

In 1808, Napoleon I 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 arc or French meridian line (French: Méridienne de France) surveyed this time by Delambre and Méchain. 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.[2]

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.


The Institut Géographique National (English: National Geographic Institute) or IGN is a French public state administrative establishment founded in 1940[1] 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 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 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, which was able to pursue field work, particularly in the Sahara. The list of maps of French Africa have lengthened notably."[3]

Recent developments

Its activities abroad begin into 1986 within a new subsidiary private company IGN France International.

From 2000, the IGN develops the concept of Reference frame on a Large Scale (référentiel à grande échelle = RGE); it is a question of completing within a deadline short digitalization the cartography of the French territory with a meter scale and according to four components: topography, land registry and address. This RGE is entirely completed at the end of 2008. Then it enter in a cycle of maintenance In June 2006, the IGN opened the service Géoportail allowing the cartographic visualization of the French territory on a Web navigator and using on one hand funds of air photographs and on the other hand the digitized maps to the 1/25 000. “Phase 2” of Géoportail was put on line one year later, with a new ergonomics.

At the end of 2006, the IGN was implied in the production of a receiver GPS, for the excursion and automobile navigation, called Evadeo. The software of navigation was provided by BCI navigation (replaced in 2008 by CompeGPS), the road data are of Navteq and it puce GPS of SiRF, and the IGN provides a part with extracts of its maps at various scales.

In June 2007, the IGN started offering a service whereby it is possible to have a map printed centred on any location in France. This is similar to the service offered in Great Britain by the Ordnance Survey.

In July 2007, Géportail - an online map service - began offering 3D movable views in a similar style to GoogleEarth. To use this function, it is necessary to install the plugin TerraExplorer.


The IGN is the successor to the geographical Service of the Army (SGA), which was founded in 1887 and disbanded in 1940. The old maps produced by the SCA were divided into two batches: one which remained at the Institute and one which joined the military files of Vincennes. The general Louis Hurault, who was at the origin of these modifications, was the first director of the IGN. He tried, in vain, to recover the material shared by the Germans. A law in ten articles is signed the 14 in order to define the functions of the IGN. The statutes had been signed the 8. This established, in example, the national School of geographical sciences in order to train Cartographical engineers.

During the Second World War, the IGN became famous for its counterfeiters. The cartographers are indeed experts in penmanship and the material necessary to the production of fake identity papers was available to the Institute. Certain engineers of the IGN were in contact with the services of allied information based in London. In secret, they brought a complete set of maps to London covering France and North Africa in order to replace maps destroyed in a bombardment.

The agents of the IGN took an active part in armed resistance in 1943. Several agents were shot by the Germans or died in action. Between September 1944 and on May 8, 1945, the IGN was under the control of the “provisional government” and most of its personnel and of his services are transformed into “military geographical Service”. At the end of the war, the IGN received the thanks of Generals Bradley and Eisenhower.

Between 1945 and 1946, the debate is intense concerning the future of the IGN, last creation of the Third Republic. A law is finally signed the 8. It confirms the membership of the IGN to the Ministry of works and create the “geographical Section of staff of the Army”, new section in charge of the military map.

In 1947, the IGN receives the mission of covering the whole France, but also all the dependents’ territories, like North Africa, Western Africa, Madagascar, the countries associated with Indochina and the departments and overseas territories. The task is considerable with more than 12 million km ² being covered. The independence of these countries will have as a consequence the creation of national services in each country (examples: DTGC in Senegal, IGN-N in Niger).

The IGN then initiates a period of active co-operation with the majority of these organizations by providing some engineers of the IGN and also receive the students of the ENSG who intended to become the executives of the cartographic services of new independent countries. The activity of the IGN apart from the French territory also develops by the control geodesic project(Ecuador 1975, Libya 1979, Saudi Arabia 1981), of cartography (Saudi Arabia, Burundi, Senegal, Mali, Ivory Coast, Togo, Benin…).

1982 to 1988, the control of a large topometric project and numerical cartography in Riyadh is the occasion to massively introduce digital techniques into the processing production; in parallel, the idea of a topoland data base emerges at meetings of the “national Commission of the geographical information” chaired by Guy Lengagne; this commission returns his report in 1983 and outlines numerical geographical information then in agreement with the period of the basic map with 1:25 000. Publicly owned establishment related to administration since the January 1, 1967, it is placed under the supervision of the ministry for Transport, the equipment, tourism and the sea.

In 1971, the IGN and the CNES form the “Group of research of geodesic space”. This collaboration between the IGN and the CNES continues with the launching of the program SPOT the 5. The launching of satellite SPOT-1 takes place the 22.Six days after take SPOT-1 in orbit, the IGN create its programme of “data bases launches”, the “data bases”. The data base of the cities, the data base of leveling distribution, the data base of geodesic distribution, the aerial missions data base and the toponyms data base were progressively establish . The “Topo data base”, bases of topographic data digitized, covers from now on the whole France and include nearly two million toponyms .

See also


  1. Available on the site of National Library of France
  2. "Earth, Figure of the". 1911 Encyclopædia Britannica. 8.
  3. Gottman, Jean. 1946. “French Geography in Wartime.” The Geographical Review. Volume 36, 1946. Page 89.

Further reading

  • Jacques Lévy, Patrick Poncet, Emmanuelle Tricoire, La Carte, enjeu contemporain, La Documentation photographique, La Documentation française, Paris, 2004.
  • Philippe Rekacewicz dans Le Monde Diplomatique, février 2006 "La cartographie, entre science, art et manipulation". 4 September 2008..
  • Philippe Rekacewicz dans Le Monde Diplomatique, mai 2000 "Regards politiques sur les territoires". 4 September 2008..
  • Carte de Cassini - Carte manuscrite de la rive droite de la Vallée de la Vesdre par les ingénieurs géographes français avec la collaboration de Cassini, 1745-1748. Vincennes, Archives de la Guerre. 4.6. B 36 à 42, feuille F. in Etienne Helin, Lemoine Isabeau Claire, Bruxelles, Crédit communal, 1980.
  • Thierry Lassalle : Cartographie 4000 ans d'aventures et de passion IGN-Nathan Paris 1990
  • Collectif : "La petite compagnie : au hasard des souvenirs des derniers arpenteurs de l'IGN" Éditions APR-IGN Cognac 1992
  • Collectif : "La boîte de Pandore : autres souvenirs retrouvés des derniers arpenteurs de l'IGN", Éditions APR-IGN, 1995
  • "Les cahiers historiques de l'IGN", n° 1, avril 1999, "1940-1990 : une histoire mouvementée"
  • "Les cahiers historiques de l'IGN" n° 2, juillet 2001, "du Tropique au Cercle Polaire" IGN Paris 2001
  • "Les cahiers historiques de l'IGN" n° 3, juin 2003, "de l'Empire colonial aux ageces de l'IGN : 1940-1973" IGN Paris 2003
  • "Les cahiers historiques de l'IGN" n° 4, juin 2003, "les bâtiments" IGN Paris 2002
  • "Les cahiers historiques de l'IGN" n° 5, janvier 2005, "Sur la frontière Guyane - Brésil 1956 - 1961 - 1962 - 1991" IGN Paris 2004
  • "Les cahiers historiques de l'IGN" n°6, juin 2007, "l'Ecole nationale des sciences géographiques (ENSG) 1941 - 2004" IGN Paris 2007
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