Albert Lepetit

Coutureau optical square

This optical square was invented by Alfred-Alexandre Coutureau ingénieur-géomètre in Saint-Cloud, France and patented in 1885 in France (pat. 169887), in Luxembourg (pat. 604) and in Germany (DRP 36083). According to the Berthelemy catalogue, the Coutureau optical square was adopted for use by the Italian Cadastre.


Several (slightly different) versions are known: see Berthelemy 1890, Muret 1906, Morin 1910, and Secretan 1924. The optical square pictured at right is identical to the 1922 version as sold by Secretan in their 1924 catalogue.












Charles Muret; Topographie: applications spéciales à l'agriculture; arpentage, nivellement, Cadastre 1906, page 69. Internet Archive.

Lepetit Timeline


 Gambey's former apprentice Lorieux establishes a workshop with 

Schwartz: Schwartz dit Lenoir.

 Mörzer Bruyns; Sextants at Greenwich 2009, page 64.

Baudry et Lorieux succeed Schwartz dit Lenoir. The company lasts about a year. Both makers are listed separately in subsequent years in the Paris Firmin-Didot Frères directories. 

 Firmin-Didot Frères Annuaire général du commerce de l'industrie 1855, page 748. Google Books.
 1880  Hurlimann acquires Lorieux's workshop.  Archives Commercials de la France 1880, No. 44, page 720. Gallica.
 1895  Ponthus & Therrode is established.  Archives Commercials de la France 1895, No. 49, page 763. Gallica.
 1895  Ponthus & Therrode acquire A. Berthelemy's workshop.  Syndicat des constructeurs en instruments d'optique & de précision (France) 1901-1902. p.204-213. Smithsonian Libraries.
 1900  Ponthus & Therrode acquire Maison A. Hurlimann.  Syndicat des constructeurs en instruments d'optique & de précision (France) 1901-1902. p.204-213. Smithsonian Libraries.

 Albert Lepetit succeeds M. Ponthus, the workshop continues business until ca. 1950. Lepetit may have been active in the Ponthus & Therrode company from ca. 1915.

 La Ceramique et la Verrerie, 25th January 1922. Gallica.

 Frederick Lang becomes a partner in Etablissements Albert Lepetit

 La Machine Moderne, Avril 1929, page 209. Gallica. 

 Etablissements Roger Poulin succeeds Lepetit