I've read about a third of this book so far, and I'm finding myself wishing the author had included more figures, sketches, and diagrams. There are already quite a few figures, sketches, and diagrams in it, but they lack callouts and arrows pointing to specific items of interest with a description, and they feel very disconnected from the text. The main reason I wish he had used even more sketches is that the author seems to assume the reader knows what all the parts of a cathedral are called. He randomly tosses out references to "triformiums" and "diaphragm wall" (there are lots of walls, which one is he considering the diaphragm wall?). The glossary at the back offers a written description of SOME of these confusing terms, but architecture and structural engineering are by nature graphical and visual fields... he needs an overall plan and section of a typical cathedral with each area and piece identified... a visual glossary. I've been so distracted trying to figure out what he is referring to that I haven't had a chance to evaluate anything else about his book.