Saint Helena Meridian

Saint Helena Meridian (French: Méridian de Sainte-Hélène) begins at the initial point of the Washington meridian, in latitude 31° north, and longitude 91° 09' 15" west of Greenwich, passing one mile east of Baton Rouge, extends south to the Mississippi River, and governs the surveys in the Greensburg and southeastern districts of Louisiana, east of the Mississippi River.

Source

• Raymond, William Galt (1914) (via Google Books). Plane Surveying for Use in the Classroom and Field. New York: American Book Company. http://books.google.com/books?id=68I3AAAAMAAJ&dq.