As the title already states, the book, “Descrizione e studj dell’insigne fabbrica di S. Maria del Fiore”, is about the description and a study of the famous Florentine metropolitan factory S. Maria del Fiore. This is why I believe the book is like a description how the building is built. What the title also suggests, is that the book is dedicated by the architect Bernardo Sansone Sgrilli and the Royal Highness of Gio. When we take a look on the list of contents, we can see it starts with a dedication and goes on with a description of the building. And the we can see the book is divided in different „Figuras“. When I continue with taking a look on the pictures, its getting clear the nearly only pictures are on the end of the book. But if there are, they are covering the whole page of the book.
If I now compare the look of the book with the pictures you can see that it makes completely sense that the book is large and thin, because the pictures need to be big because only then you can see exactly see how the building was built.
If I now take a look on the author, whose names are Sgrilli, Bernardo Sansone and some others. I think he wrote the book to clarify how the building was built and why do we need this building and for what it is good for, and with which method it was built and wich materials it contains.