History of Florentine Architecture in the 18th Century - From Galileo's Theory to the Works of Viviani and Martelli
Florence was one of the vital centers of the New Science, thanks to the presence of Galileo Galilei and the Accademia del Cimento, established by Leopoldo dei Medici in 1637 (he had been educated by Galileo). The purpose of the academy which was forced to close in 1667 was to launch the study of experimental physics. Research on Galileian solids of identical strength, and more generally on static calculations of structures began affecting only a few fragmentary parts of architecture.
If these fragments did not yet succeed in resolving themselves into a new architectural theory, they did serve as the beginnings of a concept of architecture which, through Carlo Lodoli's and Pierre Patte's formulas, led to mid-nineteenth century structural rationalism. Galileo's pupils who were working in Florence were interested in some particular aspects of architecture.
In 1644 Evangelista Torricelli offered a mechanical explanation of resistance offset by thin metal rings used in construction to reinforce cracked columns; they were used on the columns of the Uffizi and the courtyard of the Palazzo Medici, the examples that he was able to observe directly. Science was particularly concerned with plumbing and Buontalenti's empiricism in the invention of water pipes still fundamental for Giulio Parigi and Alfonso Parigi the Younger, had to meet the challenge of the scientists' experimental research and studies, which included the treatise Della misura delle acque correnti (1628) by the abbot Benedetto Castelli, a pupil of Galileo.
In Florence, one of the most important cases that involved science in architecture was the study of the stability of Brunelleschi's dome. In the sixteen forties, Gherardo Silvani, in his capacity as architect of the Opera di Santa Maria del Fiore, was the first to discover the cracks on the interior and exterior faces of the dome, and started restoration work. In 1691 Bernardo Possi, he too architect of the "Opera", studied the cracks and evaluated their gravity. In 1694 the Grand Duke asked the elderly mathematician, Vincenzo Viviani for help. In 1661 he had already worked on the dome, during the restorations of the lantern that had been damaged by lightning, and in 1692 he published a study of the vaulted ceilings. Along with Viviani, Giovan Battista Foggini, and one of their disciples, Giovanni Battista Nelli, appointed "Provveditore dell'Opera del Duomo" were also involved in the project. Nelli's father had studied with Evangelista Torricelli. Viviani asked Paolo Falconieri for information about the reinforcement of the dome of St. Peter's in Rome, which had been done with steel collar beams, the late sixteenth century ideal remedy for guaranteeing stability of domes.
Perhaps they also consulted Filippo Baldinucci who had dedicated some considerations on the reinforcement of the dome in his biography of Bernini (1682). The cause of the cracks was attributed to the excessive weight of the lantern and the upper part of the dome; they decided to strengthen the dome by encircling it with four steel collar beams between the dome and the imposts. The worsening of the cracks, detected with bronze and marble wedges, prompted the Grand Duke to approve the decision on 20 June 1695. While the first collar beam was being made, Carlo Fontana, Francesco's son, one of the greatest experts in strengthening and restoring domes was also called in. Both confirmed the validity of the collar beam solution. Viviani and Nelli concurred with the criticism of Alessando Cecchini, somewhat of an unknown up to then, who attributed the causes of the cracking to yielding of the foundations, that supposedly occurred not long after the work on the dome was finished. He demonstrated the futility of using steel collar beams.
Thus, perhaps at the beginning of 1697 it was decided to do away with [hem, and work on the static features of the constructed domes, like Brunelleschi's, without centerings.
Some of the leading figures of the New Science were employed by the grand dukes for engineering projects in Florence and Tuscany, thereby contributing the development of a new builder, an expert in calculations, hydraulics, plumbing and material strength. In addition to consulting on the stability of the dome, during the final period of the Medici government, Viviani was called in to work on the Arno River near Florence. The Riccardi family asked him to enlarge the Palazzo Medici where he probably worked on Michelozzi's façade.
Evaristo Torricelli was consulted on matters concerning the movement of waters and for reclaiming the Chiana area. Leonardo Ximenes, scientist and Jesuit priest, founder of an astronomical observatory in Florence was appointed architect of the Regie Fabbriche and in the seventeen-fifties the Lorraine rulers asked him to work on reclamation of the Bientina, Valdichiana and Maremma areas, and to build roads and bridges in Tuscany.
Technical-scientific knowledge became preponderant in the cultural training of architects, as demonstrated by figures such as Alessandro Cecchini, Luigi Orlandi and Giuseppe Martelli. In this sense Anton Maria Ferri was an outstanding figure. After training with Ferdinando Tacca's school he directed several works; he was well versed in mathematics and wrote a treatise on perspective, fortifications and artillery; he was appointed "Lettore di architecture civile e militare" (lecturer in civil and military architecture) at the Accademia dei Nobili, established by the Grand Duke Ferdinand in 1689.
His pupils included Ferdinando Ruggieri, author of the first geometric rendering of the Florence city map ("in its real dimensions" as he himself described), and Alessandro Galilei, a relative of Galileo, who also worked on the study of building techniques, stererometry, plumbing, etc., in 1720 the Grand Duke Cosimo III appointed him to the post of "Ingegnere delle fortezze e fabbriche di corte" (Engineer of court buildings and fortresses), where he remained until he moved to Rome in 1731.
It is known that the radical ideas of Lodoli, who worked in Venice, represented the most important attempt at basing architecture on Galileo's theories and research on material strength. Lodoli's ideas that were disseminated mainly in the writings of two of his pupils, Francesco Algarotti and Andrea Memmo, were already circulating in Florence by the mid-eighteenth century. The Florentine abbot, Vincenzo Martinelli was a great friend of Lodoli. In 1784-85 Memmo said that, shortly after finishing Lodoli's lessons, he had written a letter to Marchese Niccolini of Florence about Lodoli's ideas.
From Lodoli's follower Angelo Comolli, friend of Giuseppe Del Rosso, Lorenzo De' Vegni received a copy of Alessandro Tesauro's critique of De Architectura by Vitruvio, which he maintained (1794) provided the inspiration for "l'espositore dell'architettura lodoliana" (the exponent of Lodolian architecture) (Memmo). The correspondence between Del Rosso and De'Vegni over the years between 1790-98 contains references to radical Italian and French theoretical groups. They discussed the "caprices" and "abuses" (a term that De'Vegni borrowed from Palladio's treatise, with which he was thoroughly familiar), the need to re-establish a tectonic logic of the order (such as eliminating the tympanum, reminiscent of the roof from the interiors), and along with Lodoli's theories, they made reference to those of Claude Perrault, Marc-Antoine Laugier and Francesco Milizia.
To control the proportions of the plans, De'Vegni taught his students to use Galileo's compass and made them study the treatise by the Jesuit Michele Marchetti. Using the tartar technique that he invented, De'Vegni made the busts that were to be mounted in the niches on the façade of the Palazzina della Meridiana (Pitti Palace) designed by Paoletti. De Rosso contributed to the dissemination of building techniques, particularly French methods.
In 1789 he published a concise construction manual Pratica e Economica dell'arte di fabbricare, in which he presented ideas and technical solutions by Alberti, Scamozzi and the most recent contributions of French scientists and engineers such as Bernard Forest de Belidor In 1793 (Della costruzione economica delle case di terra), propagated the "pisé" method, rediscovered by Patte and François Cointeraux, and in 1797 (Della facile costruzione de' ponti di legno per torrenti e piccoli fiumi) he proposed the construction of single-span bridges according to a technique inspired by the structural concepts of Philibert De l'Orme.
Fabroni's invention (around 1790) of lightweight bricks made with fossil flour and inspired by ancient construction techniques achieved international renown. On 15 September 1606 Bernardo Buontalenti had designed an arch in stone quoins with metal reinforcements ("collar beams and stone arches"), probably developing further construction methods that Vasari used for the Uffizi. It would only be in the early nineteenth century that reinforced stone structures to be used in Florence, whereas they had become widespread in France starting from the second half of the seventeenth century. It was Giuseppe Martelli, upon his return from a brief stay at the Ecole Polytechnique of Paris who used composite metal beams to reinforce the sandstone architrave in the Loggia Reale sul Prato (1821-30) designed by Louis de Cambray Digny.
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