I gave up reading this after three or four chapters. I'd wasted too much time because of technical errors. As the book warns, the book is about highly hazardous subject matter, so it simply should not be in print when it gets so much stuff wrong. Charts have lines and lettered points on them that are not referred to in the text. Conversely, points that would be clear if the chart had been annotated are left unsupported. A circuit diagram shows a 250V supply, but the text refers to 200V. These are safety critical matters. The book explains things illogically. It's written in a very odd, cramped style with a reluctance to use "a" and "the" in the conventional places, as well as many other grammatical infelicities. It's also a very thin book offered at a comparatively high price.