The book «Architettura della basilica di san pietro…, written by giovanni battista costaguti seniore and published by his nephew giovanni battista costaguti juniore in the year 1684 already suggest in his title that it is about the architecture of the st. peters cathedral in the Vatican. What the title further says is that the architecture of the building is a work of Bramante Lazzari, Michel’ Angelo Bonarota, Carlo Moderni and other famous architects. That brings up the question how this magnificent work of the famous architects can be shown not in the real world but in a book with 107 pages.
This question brings me to my topic the Illustration. To show the Architecture of the St. Peters Cathedral Giovanni battista costaguti show a lot of illustrations in his book. After only a short part of written pages which contain a dedication, an Introduction and an Explanation the rest of the remaining pages are filled with Illustrations.
To specify what I mean with illustrations and to show how the author and publisher show the architecture of the cathedral you can divide the illustrations in three different drawing types. The Ground plan, the section and the perspective. Each of them contains other information. In General, there is an order of the illustrations. First in the book are the ground plans and after them the sections. The perspectives are not in a specific order and appear randomly between the sections and the plans. Mainly each Illustration is on a separate page. In some special cases there are more illustrations arranged on one page.
The ground plans usually come with a legend to describe very detailed the specific parts of the building. For example, is every niche described further in the legend. The perspectives are usually just as themselves on a page. They show the appearance of the volume of the cathedral or the perception of a specific space. The architectural elements and also the use of the orders can best be seen in the section. In General, are the sections drawn very detailed to show for example the whole entablature with the architrave, the fries and the cornice. Sometimes also the sections are further described with a legend to explain the elements which cannot be shown in a ground plan.
To sum up you can say the book is a book to show the architecture of the St. Peters cathedral by illustrations. The ground plan, section and the perspective are used to show the architectural elements of the cathedral and to explain the spaces, but they can’t be used to rebuild elements.