138 



U. S. COAST AND GEODETIC SURVEY. 





diameter perpendicular to this is the projection of the 

 Equator. Both of these diameters are divided into equal 

 parts and the projection of the principal meridian is divided 

 mto the same number of equal parts. The parallels are 

 arcs through the divisions of the hne of poles passing 

 through the corresponding divisions of the principal 

 meridian. The meridians are arcs passing through the 

 poles and through the divisions of the Equator or the 

 diameter perpendicular to the line of poles. 



Fig. 37.— Nicolosi's projection or globular projection. 

 PROJECTION OF P. FOURNIER. 



Another conventional projection is that proposed bv 

 P. Fournier in 1(346, which is a polyconic projection with 

 meridians that are ellipses. The Equator and the central 

 meridian are developed with their true length on two 

 straight lines perpendicular to each other; the central 

 meridian serves as the major axis of all the ellipses for each 

 of which the corresponding X serves as the semiminor axis. 

 The principal meridian is a circumference of a circle. The 



