This is a very rare large-format survey chart of the coasts of Gabon and what is today known as the Republic of Congo (Brazzaville) made shortly before World War I. In 1911, France reorganized its colonial possessions in the region into a new configuration, Afrique équatoriale française (AEF), which consisted of Gabon, French Congo, Oubangi-Cahri (Burkina Faso) and Chad. In preparation for the administrative changes, France commissioned teams to conduct scientific surveys of the AEF; the coastal aspects were undertaken by the ‘Mission hydrographique du Gabon’ (MHG) led by Lieutenant Antoine Gontran Audoin. Between 1910 and 1912, the MHG conducted advanced trigonometrical surveys of the coasts and the Ogooué River.
The present chart provides a complete overview of the MHG surveys, capturing the entire coasts of Gabon and the French Congo, from the just north of Libreville all the way down past Pointe Noire, to the border of Portuguese Cabinda. The delineation of the coasts and course of the Ogooué River is precise, while fresh bathymetric soundings are noted off shore. The chart in the lower left corner notes the geodetic co-ordinates of major ports and headlands taken by the MHG’s astronomical observations.
The chart is labelled in the bottom margin as an ‘Editon provisoire’, (provisional edition), meaning that it was published as a trial issue in a very small print run.
Consequently, it is very rare, we can trace only 2 institutional examples, at the Muséum national d’histoire naturelle (Paris) and the University of Milwaukee-Wisconsin. The information on the present chart was subsequently integrated into other charts which were printed in greater quantities, becoming the seminal overview chart of this stretch of coastline for many years.
References: Muséum national d’histoire naturelle (Paris): CD 551 (4); OCLC: 882257962 & 768129651; L’Afrique française: bulletin mensuel du Comité l’Afrique française et du Comité du Maroc, vol. 23 (1913), p. 287; Bulletin de la Société royale belge de géographie, vol. 38 (1914), p. 91; Bollettino della Società geografica italiana (1914), pp. 1113.