Engineering Rock Mechanics

440 Appendix 6: Hemispherical projection

vectors. For example, N for normals, D for lines of maximum dip,

superscript R for rotation (about the drawing pin), superscript prime or

I for inclination (Le. movement along the small circles), subscript

numbers to identify particular vectors (or planes).

4. Make notes on the tracing paper as you go: this helps others
   understand what you’ve done, and gives you a valuable revision guide.


5. When rotatindinclining planes, always use the normal to the plane,
   never the lie of maximum dip (this is because the normal is unique,
   whereas the line of maximum dip is arbitrary).


6. Never write on the projection itself: you should always write on the
   tracing paper.