The construction techniques and methods for organizing labor used for Bernini's colonnade in St. Peter's, Rome

The diary of Pope Alexander VII Chigi (1657-1668) is full of references to the ongoing construction work on St.Peter's Colonnade (1657-1668), and he frequent]y complained that the work was «moving very slowly» and urged the people in charge to work more quickly.' He clearly wanted to see the colonnade finished within the 60 months scheduled for its completion by the Congregazione della Fabbrica di San Pietro, for which Gian Lorenzo Bernini (1598-1680) was paid 60 scudi a month throughout the whole period of construction,2 Figure l. The five years allotted for building this impressive structure (which at the time was compared to ancient Roman buiJdings) was not over optimistic, particu]arly if one considers that the work was originally supposed to be done by the Reverenda Fabbrica di San Pietro. The Fabbrica had been in charge of construction and maintenance in St.Peter' s since the early 16th century.] It was a very efficient organization, with such a highly skilled technical staff that it was able to finish bui]ding SLPeter's cupola in just 22 months, quite a technological feat for the late 16th century. Like many other organizations set up throughout Italy to promote religious architecture, during the 17th century the Fabbrica had an increasingly strong influence on Roman construction in general, in terms of artistic choices, management policies, and spreading architectural knowledge. This was also because the Fabbrica's architects, master bui]ders and highly speciaJized workmen were quite mobile, meaning that they worked on other construction sites around Rome, spreading their Maria Grazia D' Amelio