The stereographic projection

E. J. W. Whittaker

Teaching aims

To provide a practical and theoretical introducion to the stereographic projection to enable students to use it in morphological crystallography and X-ray textural studies of polycrytalline materials.

Level

Normally first year undergraduate, but there are no concepts involved that would not be available to students one or two years earlier than this.

Background

Simple geometrical constructions. Some applications may require a knowledge of spherical trigonometry, but this is not needed to understand the subject as presented.

Practical resources

A ruler and compass and tracing paper. However the method will only come to life if it is applied to some real data such as measurements of interfacial angles crysal models using a simple contact goniometer (a protractor with a hinged arm).

Time required for teaching

One or two lectures. These would probably be within a series on morphological crytallography and the practical work (about 6 hours) would form part of such a course.