1913•Mineralogical Magazine and Journal of the Mineralogical SocietyRequires access
A new stereographic protractor
George Smith
Open publisher page 0 citations
Abstract
In the stereographic projection (fig. 1) ABA'B" is the primitive circle, having the same radius a as the corresponding sphere ; ATA'T" is the circle representing a great circle on the sphere inclined at an angle θ to the plane of the projection ; O and C are the centres of the primitive circle and the circle ATA'T' respectively. CO are joined and projected both ways to meet the circles as shown.