Wentworth-Smith mathematical series

In mathematics, projective geometry is the study of geometric properties that are invariant with respect to projective transformations. This means that, compared to elementary Euclidean geometry, projective geometry has a different setting (projective space) and a selective set of basic geometric concepts. The basic intuitions are that projective space has more points than Euclidean space, for a given dimension, and that geometric transformations are permitted that transform the extra points (called "points at infinity") to Euclidean points, and vice versa. Properties meaningful for projective geometry are respected by this new idea of transformation, which is more radical in its effects than can be expressed by a transformation matrix and translations (the affine transformations). The first issue for geometers is what kind of geometry is adequate for a novel situation.

This is an excellent manual for the practical machinist. This book provides a lot of information about machine shop practice along the necessary math to turn out quality metalwork. There are many examples and exercises, the reference tables and formulae are really a good reference. Although it can be outdated by current standards this book remains a valuable reference manual for the machinist.