All Sides to an Oval: Properties, Parameters, and Borromini’s Mysterious Construction By Angelo Alessandro Mazzotti

“The idea of this book is not to dispute whether and when polycentric ovals were used in the past. It is to create a compact and structured set of data, both geometric and algebraic, covering the single topic of polycentric ovals in all its mathematical aspects, and then to illustrate two very important case studies” (p. 2). In the Introduction (Chapter 1) with this statement Mazzotti explains the contents of his book. He is a mathematician, and mathematic is the approach to the subject of the book, but the links with descriptive geometry and architecture are evident in the whole volume. The problem of polycentric curves’ construction is faced in architectural Treatises (Serlio, 1619; Ruiz, 1560 ca.; Ge-labert, 1653…), as well as in books on geometry and stereotomy (Bosse, 1655…), and it has also been dealt with since antiquity, even empirically, in the architectural ideation and construction. The volume, as specified by the author, in addition to collecting and reworking some of his previous writings on the subject, addresses many new topics.