(As I can assume the book Mémoire historique sur le Dôme du Panthéon Français written by the French architect Jean-Baptiste Rondelet is about the French pantheon and especially about its dome. The book is divided in four different sections that contain a description of the pantheon, details of its construction, if its walls and supports and are strong enough and the accidents that occurred and their reasons.)
As we can see on the first image the books layout is really clear. The page number placed at the top and at the beginning of a new chapter a clear headline and a divider.
Every now and then some remarks at the side of the pages can be seen (picture two). These refer to other pages in the book or explain a certain word.
At first the third picture confused me because the size is different comared to the rest of the book (as well as the size of the other plans). I assume that they are stitched to the book, as it can be seen on the left, and are then folded to fit into the book.