J42 TJ. 8. CX)AST ANB GEODETIC SURVEY. 



By solving these linear equations for ^ we obtain 

 be TTX 



Hence 



, TT^rx sec (f 



^P~X[x25-(7r^-4X2) y\ 



XFpon the central meridian we liave 



^ = 0, ^/'^O, l-ia=l, 



iuad 



fcp = sec 



upon the principal meridian 



cos^=-U-|sin^j» 

 a relation that is evident from the figure. 



i^G. 39.— Projection of P. Foumier. 



