In making this review, I'm amazed on the date I'm writing it to be the first one, this book has been in print for over half a century and I can't believe I'm the only one who ever found it useful. The author Allyn Thompson, was a postmaster by profession, who led a group of a group of amateur telescope makers at the old Hayden planetarium in the 1940's to the time of his death in the mid 1950's. The book itself is an outgrowth of a series of articles he wrote immediately after the second world war which appeared in Sky and Telescope magazine. Though the size and focal length of the telescope he describes building (a 6-inch f8 reflector) is small by the amateur standards of the last 20 years, it is still probably the best size for a novice wishing to grind and polish the primary mirror themselves to start with. And it is in his step by step discriptions for making the primary mirror of a Newtonian reflector that this book excels. He tells you in a simple straight forward way the theory and history of the telescope, materials needed to grind and polish your own primary mirror, how to do it, how to test it (his discription of the Focault tester and using masks with it are in my opinion the still the clearest written for the beginner). He does not attempt to scare you away with horror stories of all the terrible things that can happen to you, turned down edge, dog biscuit ect, a flaw you find in the old "ATM" books I and II edited by Albert Ingalls. Thompson identifies possible problems, but then guides you through them with straight forward techniques. His "button laps" were a wonderful inovation for small mirror making and molds were widely available when this writer polished his first mirrors 30 years ago. Unfortunately nobody I know of today sells the molds commercially, but Thompson shows you how to make them yourself if you want to try it. As far as the mechanical construction of the telescope, the book is dated. Not many people today would use babbitt filled pipe fittings to make a mount, not since the easily built and more stable Dobson mount became the standard about 20 years ago for home builts (for a good book on that see Richard Berry's "Build Your Own Telescope"). But John Dobson was just starting to build scopes about the time Thompson died so he can't be blamed for never having seen one, he was on the other side of the country. All in all this book has held up well for something written 50 years ago. I wish I'd had a copy of it when I built my first scope. I didn't discover it till after I'd made my second mirror and I believe things would have gone a lot smoother had I read this first instead of using the old ATM books. It's too bad Allen Thompson isn't with us today to have updated the mechanical stuff, but as a mentor for your first mirror, you can't beat this book!