If you want to learn and about design cyclones, this is *the* book for it. Originally, I used the first edition, and this book was already very good then. I have a 2nd edition now. The second edition is longer and contains more material.This book is well written. The writing is concise, and there aren't very many errors. Equations are clearly presented. The variables used are clearly defined in a list of variables in the front of the book.There aren't any color photos, but the black and white diagrams and photos are of high quality.The book contains interesting things about cyclone history if you are a technological history buff, but if you are an engineer just looking to get down to the technical details, it is very easy to skip over the beginning chapters, and go straight to business. I actually used this book to design two cyclones for a very demanding application, and they performed well for me.One final thing that I should note is that although the title is called "Gas cyclones and swirl tubes," there isn't very much information in this book about swirl tubes. Almost all of the material in the book is about cyclones. This isn't a huge problem though because cyclones are much more commonly used, and the two devices behave similarly.