Formal innnovations in two sixteenth-century helicoidal staicases of Vignola and Mascarino

Some recent personal studies on the most representative helicoidal staircases of the Renaissance and Baroque were an opportunity to compare two emblematic figures of the '500 Italian, Vignola and Mascarino. The first is known to all, the second is certainly less well known though new historical studies are re-evaluating his work also as architect. This paper aims to demonstrate how a careful reading and interpretation of two of their works, particularly significant on the same theme, allows to focus with great evidence the project control skills through application of the principles of geometry and their care and attention in control of the realization, always thanks to their geometrical expertise. The study finally made it possible to shed new light on the real contribution of Ottaviano Mascarino in the late Renaissance architecture, anticipating a few decades some formal characteristics of the Roman Baroque.