The sub-title on this book is "a technical manual" which is just not accurate. This book is an excellent overview of some of the techniques and tools used in furnace type glass blowing. It is not a technical or instructional manual, or a least not a good one. Anyone who wants to learn how to blow glass should go buy a copy of Edward T. Schmid's books and work from them.
This book is written in a narrative style as if it were a complete set of instructions as to the glass blowing process but it tends to make some big assumptions as to the students pre-existing knowledge and glosses over the details of the process. Worst of all it give some very bad advice as to eye protection, instructing beginning glassblowers to utilize didymium eyeglasses for safety. Didymium's are intended to protect the lampworkers eyes from the sodium flare created when working soft glass at the torch. They offer little or no protection from infra-red radiation which is the greatest danger to the eyes of the furnace glassblower. The false sense of security is worse than no protection at all since the dark tint of didymiums will open the pupil and allow even greater amounts infra-red to reach the retina than would if the didymiums were not there. At least the person without any eye protection will not stare into the glory hole for prolonged periods.
I also find the sequence of instruction to be very inappropriate. Immediately after the author introduces the student to the basic use of color rod and powdered color he jumps ahead to one of the most difficult techniques to master, incalmo (encalmo), the joining of two separately blown vessels in to a single vessel while still hot on the blowpipe.
My last complaint is less important but bothersome to me. The author assumes that all students working out of the book will have an assistant at all times. This may be the case in the UK but certainly is not the case here in North America.
Overall a fair overview of glassblowing for the glass collector or the curious but not a textbook, nor a "technical manual".