28 U. S. COAST AND GEODETIC SURVEY. 



Therefore 



tan ^Z' = 0, or ^ = 0, and the projection belongs in the class 

 of the rectangular polyconic projections. 



The equations for the magnification along the parallels 

 and along the meridians^ respectively, are for the sphere 



But 



cos X + cos (p 



cos e= 



and 



1 + cos X cos (f 



bd _ sin (f 

 dX~l +COS X cos <p' 



By substituting these values in the formulas for hia and Ic^ 

 we obtain 



— a cot (p cosec <p (cos X + cos <p) , , 



V- ~ ^ + a cosecV 



, 1 + cos X cos <p ]_ 



1 +COS X cos (p 



-, _a cot ip sin <p 1 



^"~a cosv * 1 +COS X cos v? l+cosXcos<^ 



The projection is therefore conformal, since the meridians 

 and parallels form an orthogonal net and the magnifica- 

 tion along the meridians and along the parallels is the same. 



