Complex sentence: In early modern times, other gnomons were also built in several Italian and French churches in order to better calculate astrological events, such as Santa Maria del Fiore in Florence, San Petronio in Bologna, and the Church of the Certosa in Rome.
Split into simpler sentences: In early modern times, other gnomons were also built in several Italian and French churches in order to better calculate astrological events. Those churches are Santa Maria del Fiore in Florence, San Petronio in Bologna, and the Church of the Certosa in Rome.