This was my bible back in 1966 when I made my first mirror, an 8". At that time, there were a lot of things I just couldn't grasp as a sophomore in high school. However, with the help of a friend with lots of experience, I got over the rough parts and made a pretty decent mirror. I can't comment on the latest edition as I don't know how much was updated from that tried and true technology from so long ago. All I know is that the version published in the 60's was relevant and accurate. This is the book from which I learned at least one new vocabulary word, "tyro." I had to look it up. The rest of the language was well explained including all the optical terms that are a regular part of my language today. If nothing else, this is a solid book to start out telescope making. It should be used in conjunction with other books on the subject to give you a more rounded view on making your first mirror. However, it stands on its own as a mirror-makers bible. It may not have the depth of math the Texereau book or a few of the others does, but it gets the job done. Worked for me. Highly recommended.