The book Architectura by Wendel Dietterlin explains architectural design and décor based on five different levels.
After a brief greeting to the reader and an explanation of terminology and shortcuts used in his drawings (specifically “for the youth”), the author gets straight to his theory on architecture and how it is supposed to be.
Those are defined by several types of pillars, such as the Doric style as an example. Dietterlin applies the principles, usually used to categorize columns, to all other architecture as well.
While there are only short texts laying out the core design rules, over thirty drawings accompany and support each chapter’s message.
The version of the book I had a closer look at, was printed in a A4 format. However, the original might have been of a different size. As far as I could tell, the original book had just over 200 pages, of which at least three fourths were drawings – very much of the same motives (doors, window frames, fountains, columns etc.) in many different versions.
I personally find it interesting, that not a lot is known about the so called Wendel Dietterlin (not even why he calls himself by said fake last name) and he still seems to be an acknowledged author.