He became an engineer and mechanician, and got employed by the King and the Royal family for producing globes and spheres.

During his life, he is known to have produced a total of two publications; both are improved and updated editions of John Flamsteed's star atlas, "Atlas Coelestis" (Flamsteed 1729). These two works were published in French as "Atlas Céleste," in the years 1776 ad 1795: His first work, labelled the second edition of Flamsteed's atlas (Fortin 1776), included work by Pierre-Charles Le Monnier, F. Pasumot, and Nicholas Louis de Lacaille. The second one, the third edition of "Atlas Céleste" (Fortin 1795), was updated by Jerôme de Lalande and Pierre Méchain. Because of Méchain's involvement, it includes, in particular, many of the nebulae discovered by Messier and Méchain, many cartographed here for the first time, and in particular most of Méchain's additional findings, i.e., M104, M105, M106, M107, M108, and M109B (NGC 3953). It also includes most of the nebulae printed in Johann Elert Bode's star atlas of 1782, "Vorstellung der Gestirne" (Bode 1782) which had in turn used the data from Fortin's 1776 atlas. Fortin's 1795 edition was also published in Portuguese in 1804 (Fortin 1804).

Fortin died in 1831 in Paris.

.. more to come soon ..

• Fortin from meteo-maarssen Digitale Bibliotheek (in Dutch) Comparative presentation of the three editions of Fortin's Atlas Céleste (Fortin 1776, 1795 and 1804)

References

• Johann Elert Bode, 1782. Vorstellung der Gestirne auf XXXIV Kupfertafeln. Gottlieb August Lange, Berlin and Stralsund.
• John Flamsteed, 1729. Atlas Coelestis. By the late John Flamsteed. Edited by Margaret Flamsteed and James Hodgson. London.
• Jean Fortin, 1776. Atlas Céleste de Flamstéed, approuve par l'Académie Royale des Sciences, et publié sous le privilege de cette Compagnie. Seconde Édition. F.G. Deschamps, Paris. Includes improvements by Pierre-Charles Le Monnier, F. Pasumot, and Nicholas Louis de Lacaille. Available online at Giangi Caglieris' site. Also was available online at the Linda Hall Library, Digital Servies. Giangi Caglieris has identified 18 Messier Objects in this atlas. The present author [hf] can verify this number, and has found the following: M2, M7, M9, M10, M11, M12, M13, M15, M22, M27, M28, M31, M32, M33, M42, M44, M45, and M55. He could also find Flamsteed's "nebula" 55 And (which is actually a normal star), and NGC 6231.
• Jean Fortin, 1795. Atlas Céleste de Flamstéed. Troisième Édition, Revue, corrigée & augmentée par les Citoyens Lalande & Méchain. Belin Lamarche, Paris. Images of the maps of this atlas are available online on Henk Bril's site. Henk Bril has identified 95 nebulae, including 85 Messier objects (2 at wrong positions, and another 4 duplicated at wrong positions) and 10 others, including 3 asterisms and a duplicate wrong position of the LMC. He also identified a prediscovery observation of Uranus, and a number of variable stars including novae and supernovae. The atlas was also available online at the Linda Hall Library, Digital Servies.
• Jean Fortin, 1804. Atlas celeste arranjado por Flamsteed. A translation to Portuguese language of the 1795 edition.

• Asit K. Biwas and Argaret A. Biwas, 1972. Fortin, Jean Nicolas. In: Charles Coulston Gillispie (ed.), 1972. Dictionary of Scientific Biography, Vol. V, p. 78. Scribner, New York.