ON AUGUST 19, 1418, competition was announced in Florence, where the city's magnificent new cathedral, Santa Maria del Fiore, had been under construction for more than a century: Whoever desires to make any model or design for the vaulting of the main Dome of the Cathedral under construction by the Opera del Duomo-for armature, scaffold or other thing, or any lifting device pertaining to the construction and perfection of said cupola or vault-shall do so before the end of the month of September.