Studies for Students: The Stereographic Projection, a Handy Tool for the Practical Geologist

Abstract

4On the Graphic Method of Representing Faults and Strata, Jap. Jour. Geol. and Geog., Vol. XIV (1937), pp. 207-39. 5 Problem of Two Tilts and the Stereographic Projection, Bull. Amer. Assoc. Pet. Geol., Vol. XXII (1938), pp. 1261-71. Fisher has devised a special protractor which gives the radii of the great and small circles for a stereographic net of radius 5 cm. and scales for use with the stereographic and gnomonic projections. With its aid, the elements of any problem in spherical trigonometry may be constructed readily (on blank paper or, better, on Penfield paper, bearing a graduwith which problems of space relations may be treated with its aid. But still no American textbook of structural geology me tions the stereographic projection as a tool; and the writer's contact with colleagues and students confirms his impression that, on the whole, it is little used by geologists. It seems that there is