According to the title of the Book, the Author Teofilo Gallaccini, who was an architect, wrote a book about the errors and mistakes architects of his and earlier times have made.
His book is a so-called “trattato”, which is some sort of essay or treatise.
Teofilo Gallaccini divides his book into three parts (parte prima, seconda and terza), each divided into different chapters. In the first part the author addresses the mistakes made whilst planning and before the construction, in the second part the mistakes made during the construction, and in the third and last part he addresses the mistakes discovered after finishing the build.
The author includes a few, if not that many illustrations, to point out the mistakes made. The images are used to explain in an easier way, what has gone wrong. Some images show a comparison between two situations, one how it is, and one how it should be. Other images try to show how impact of the human eye and the human perspective, and how the feeling of a human standing there would feel like.
The thickness and size of the book could be described as normal or average. The online version shows ca. 90 pages, whilst the physical book consists of two books in one, as it seems.