The first edition of this book was universally acclaimed as the best book ever written for making a Newtonian telescope. This 2nd Edition is almost three times larger and adds to the original text new chapters on making a Cassegrainian telescope, optical windows, and equatorial mounts. Chapters on eyepieces and astronomical seeing have been expanded. Computer programs written in generic BASIC for reduction of Foucault test data. Included are indexes for the three principle magazines that carry telescope making information: Sky and Telescope's "Gleanings for ATM's" from November 1941 through June 1998, Scientific American magazine from 1925 through 1959 and the complete run of Telescope Making magazine. This book is the most complete single work available on making reflecting telescopes.