Architecture H-Project Dome of Florence

Architecture

H-Project

Dome of Florence Cathedral (1420 -- 1436)

The Dome of Florence Cathedral (a.D. 1420-36) has been described as a "miracle" of design which is in essence a blend of Renaissance and Gothic architectural building aspects. The dome itself covers an octagonal apartment which is 138 ft. 6 ins, in diameter, and is raised on a drum, with circular windows to light the interior. (Italian Renaissance -- Florence)

It is pointed in form and consists of an inner and outer shell.

The original designer of the building was Arnolfi di Cambio. However, the architect who became renowned for the construction of the dome of the cathedral was Filippo Brunelleschi. His importance is also ascribed to the fact that he was the "... first to establish the new standards in architecture." (Filippo Brunelleschi. Cathedral Dome, Florence) Brunelleschi received the commission to plan and build the dome after winning a design competition. He competed against other Florentine artists and architects, including Lorenzo Ghiberti. Work on the dome began in 1420 and was completed in 1436.

The significance of the building of the dome of the cathedral also refers to the changed and more professional status of the architect in society. This in turn can also be related to the newly discovered scientific aspects of architecture. The dome that Brunelleschi's created is acknowledged as "…the most ambitious architectural and engineering projects of its time." (Florence Duomo History - History of Florence's Cathedral)

However, it should also be noted that the construction of the cathedral's dome had been halted before Brunelleschi submitted his architectural design. The reason for this was that the construction of a dome of this size was deemed to be impossible without the use of flying buttresses. (Florence Duomo History - History of Florence's Cathedral) However, this problem was eventually overcome by "Brunelleschi's understanding of some of the key concepts of physics and geometry." (Florence Duomo History - History of Florence's Cathedral)

As noted, central to the plan for the dome were the inner and outer shells, joined with a ring and rib system. Brunelleschi's design also employed a "...herringbone pattern to keep the bricks of the dome from falling to the ground." (Florence Duomo History - History of Florence's Cathedral). Importantly, these construction techniques were seen as unique and even architecturally revolutionary during Brunelleschi's time.

Furthermore, what was also unique about the construction of the dome was that Brunelleschi was not trained as a carpenter or mason but was in fact a goldsmith and clock maker. Even more amazing, states Gartner, was how he proposed to build the dome: "...the incredible feature of his proposed solution was that he intended to build the dome senza armadura, without scaffolding" (Gartner 86). The technique for doing this was almost inconceivable at the time. Others had proposed wooden scaffolding or stone towers to support the work. Nor could Brunelleschi prove by pointing to previous experience that he could accomplish this feat. Construction began on Brunelleschi's dome on 7 August 1420. It was consecrated on 30 August 1436.

1.2. Design

It was largely Brunelleschi's knowledge of Roman construction principle that permitted him to solve the unique engineering and architectural problem that the dome presented. (Gardner 440) the design was required to deal with the various seemingly overwhelming problem of construction of a dome. In the first instance there was the problem of the space that had to be spanned; which was too wide to permit traditional wood centering as part of the construction. Buttressed walls were not possible to support the dome. ( Gardner 440) Brunelleschi overcame these problems in a unique way. As Gardner states, he "…not only discarded traditional building methods and devised new ones but also invented much of the machinery for the job." (Gardner 440) He designed the dome around a pointed arch or ogival, which is more stable in that it reduced any outward thrust that the dome might present at its base. (Gardner 440) the weight of the dome was also minimized by the design of the thin double shell around a skeleton of 24 ribs. (Gardner 440) it should be noted that this was the first time in architectural and construction history that a design of this nature had been achieved. He also "…anchored the structure at the top with a heavy lantern, built after his death but from his design." (Gardner 440)

What makes this structure so important therefore in terms of design is its octagonal vault form that stands without buttresses and transverse chains. It is a combination of Gothic and Renaissance styles, combining innovation and tradition. As Gartner states, by contrast with earlier domes "...the heavy Roman cupolas, set into massive masonry supports, have nothing in common with the lofty, gently curving dome in Florence" ( Gartner 78). What Brunelleschi achieved in essence was to free the cupola supports from the wall structure and make them into a separate framework, which prepared the way for the twenty-four-ribbed structure of the cathedral dome. Thus, the system of struts supporting the cupola is transformed into a self-supporting skeleton of ribs. This style of dome definitively ended the medieval period of architecture and "...with it the 'monumental' form of modern architecture was born. . . ." (Gartner 77). Thus Brunelleschi's edifice has to be seen as the 'modern' building which marked the end of the medieval period" (Gartner 77). It influenced architecture inestimably, and was taken up at St. Peter's and in many American capitol buildings.

When the dome was complete the Pope consecrated the finished Cathedral on Easter Sunday, 1436. "The dome towered majestically over the city of Florence, a triumph for the Florentine people and the city's most powerful family." (Medici: Godfathers of the Renaissance . Renaissance. Brunelleschi | PBS)

1.3. Construction

The task of construction is highlighted by the fact that the dome weighs an impressive 37,000 tons and more than four million bricks were used in the building of the dome. It has been said that "Brunelleschi's dome was the greatest architectural feat in the Western world." (an Engineer's Aspect: Filippo Brunelleschi's Dome)

Something of the complexity and the ingenuity of the construction of the dome can be seen in the following analysis. Both the inner and our layers of the dome are supported by "...24 stone half arches, or ribs, of circular form, 2.1 metres (seven feet) thick at the base and tapering to 1.5 metres (five feet), which meet at an open stone compression ring at the top." (Duomo, Florence) in order to prevent or reduce the outward thrust of the construction tie rings of stone held together with metal cramps were situated between the ribs. This also was supported by tie rings of oak timbers joined by metal connectors. Furthermore, "The entire structure was built without formwork, the circular profiles of the ribs and rings being maintained by a system of measuring wires fixed at the centres of curvature." (Duomo, Florence) This means that Brunelleschi understood the intricacies and complexities of structural construction in that he realised that if the dome was built in horizontal layers, it would always be stable and not require timber centring. His ingenuity and daring in the construction of this architectural masterpiece can also be seen by the fact that he designed unique wooden machines to move the required building materials both vertically and horizontally. (Duomo, Florence)

The construction of the complete dome took most of Brueslleschi's life. During this period there were many construction problems that had to be overcome. In this regard the architect drew inspiration from the dome of the Pantheon in Rome. He initially wanted this construction to be built from sandstone and marble, but he realized that would have to build the dome from bricks, due to the lighter weight that they offered as a material. The following description outlines the uniqueness of the dome from an engineering and construction perspective.

Brunelleschi knew that there was not enough timber in Tuscany to build a scaffold inside the Cathedral, and the recipe for concrete had been lost since the fall of Rome. Brunelleschi instead came up with an ingenious and completely original theory. His plans showed an inner hemispherical dome within Florence cathedral's octagonal drum. A second, ovoid brick dome was to be placed on top, and nine sandstone rings would then hold the structure together, like a barrel. To raise the bricks and sandstone beams several hundred feet in the air, Brunelleschi invented a fast and efficient hoist with the world's first reverse gear, allowing an ox to raise or lower a load at the flick of a switch.

(an Engineer's Aspect: Filippo Brunelleschi's Dome)

An extremely important aspect is the new division of labor that Brunelleschi and other Renaissance architects created. This was to conflict with the autocratic tradition of the master builders who were in control of all aspects of the design and construction. As Heller states in Labor, Science and technology in France, 1500 -- 1620;

The development of architectural theory from the time of Brunelleschi… played a great role in the enhancement and prestige of the architect. Indeed, the first use of the term 'architect' as against 'master mason' in France dates from 1511 and reflects the increasing influence of Italian ideas" ( P88). Heller goes on to state that "…humanist learning in architecture not only raised the status of the architect, it also helped to foster a new division of labor in construction…"( Heller 88).

1.4. Significance

The innovative design that was exhibited in this construction was to lead to unique and progressive developments in the field of architecture. This is evidenced by the following quotation; "This manner of thinking through the project as a whole and determining every aspect of its structure, construction, and aesthetics was very different from the traditional ways of the masons and was to some extent the birth of the modern architectural profession." (Castex 52)

Brunelleschi's design and building expertise was also innovative in other ways as well. His creation of a new division of labor challenged the tradition medieval master builders who were previously in charge of design and construction. In a very real sense therefore, Brunelleschi's construction of the Dome of Florence Cathedral was the beginning of Renaissance architecture, both in terms of its design of structures and its execution using new technologies. Gartner states that, "There can be no doubt that the early Renaissance begins with his buildings" (1125).

2. Facade of Santa Maria Novella (1456 -- 1470 AD)

2.1. Background

In 1456 Giovanni Rucellai and his family commissioned Leon Battista Alberti to design and execute a new facade for the unfinished exterior of the Dominican church of Santa Maria Novella. ((Leon Battista Alberti (1404-1472)) the background to this church begins in 1219 when a number of Dominican friars led by Fra Giovanni da Salerno came from Bologna and obtained the church of Santa Maria delle Vigne as their Florentine dwelling. The building of the much larger church which is evident today was begun in 1279 according to a design by two Dominican converses, Fra Sisto and Fra Ristoro. (Santa Maria Novella - Church and Cloisters). Orlandi provides the following sequence of events (Orlandi 6 -- 7). The original church on the site dated from the ninth century AD. It was enlarged in AD 1094 by the patronage of the church canons. In November 1221 it was ceded to Giovanni of Salerno, who wanted to build a new church.

While he did not design the building itself, the architect Alberti created the facade. ( Chiu 97) the original facade was begun near the beginning of the fourteenth century but was left as incomplete around AD 1350. It comprised of "...six arch tombs (avelli) and three Gothic portals, as well as the marble squares and arches up to the level of the frieze." ( Chiu 97)

The Papal court resided in Santa Maria Novella in the period between AD 1434 and 1443. This was the period just before Alberti was commissioned to design the new facade. Orlandi states that "Between 1458 and 1470, Leon Battista Alberti, commissioned by Giovanni di Paolo Rucellai (whose name can be seen in large letters below the tympanum), designed the magnificent central portal (executed by Giovanni di Bertino) and the upper part of the facade, admirably harmonizing the pre-existent Gothic elements with the new Renaissance style." Orlandi 4) Among the design aspects that are attributed to Alberti was the hiding of the sloping roofs of the aisles with two up-turned volutes, which was the first examples of this architectural motif. The whole facade merges the lower Gothic elements with the upper Renaissance elements. ( Chiu 97) These and other design aspects will be discussed in more detail in the following section

2. 2. Design

Alberi's architectural style has been described as follows: "Alberti was above all an artist of facades - the creator of exteriors that radically altered the appearance of a building but did not directly express its internal organization as an organic, living system." ( Chiu 97)

With regard to the style and design this piece of architecture it is based on the triumphal arch, which shows evidence of a Greco-Roman influence. ( Chiu 97) the various architectural elements can be described as "...a temple-like pedimented upper story with triangular panels and scrolls on a broad base" ( Chiu 97) Furthermore, " Disciplined classical shapes with Florentine ornamentation are fitted into a medieval structure. There are possible influences of the Florentine Baptistery of San Giovanni and di Cambio's original design for Florence Cathedral." ( Chiu 97)

Alberti was also responsible for the design of both the top section of the facade and the main doorway from 1456-70. The lower half with green columns was begun in 1300 and completed by 1360. (the Facade of Santa Maria Novella)

The central problem that Alberti faced in designing this facade was that the design has to "....accommodate wall tombs already built into the lower facade and to construct a modern facade that would still be in keeping with the 13th-century Gothic structure." (Leon Battista Alberti (1404-1472)) it is important to note that, in terms of the architectural style of the period in Italy, the facade was intended as a public space which fronted the church and "… not as necessarily revealing anything about the interior." (Leon Battista Alberti (1404-1472))

Another design and construction problem was the fact that the two levels of the church were of different heights. Alberti solved this by tying them together visually with the use of the ornate scrolls on opposite ends. (the Facade of Santa Maria Novella) Alberti also used the example of the Romanesque church of San Miniato al Monte as an inspiration for his design of the facade.

Other noteworthy aspects of the design are the widening of the proportions of the facade with pillars of branded white and green marble, which are paired with Corinthian columns. (Chiu 97) Importantly, the portal was widened to remind one of the Pantheon with its "...fluted plaster door frame and coffered entrance vaults with rosettes." ( Chiu 97)

In general, it has also been suggested that in terms of original design, Leon Battista Alberti took his cue from a pre-Gothic medieval design, particularly that of San Miniato al Monte. From the Romanesque model, he "…designed a small, pseudo-Classical, pediment-capped temple front for the upper part of the facade and supports it with a broad base of pilaster-enframed arcades that incorporate the six tombs and three doorways of the extant Gothic building." (Santa Maria Novella Church) Alberti completed the design by "... adding a triangular tympanum, as well as creating the two beautifully inlaid lateral volute or scrolls to hide the slope of the roof that covers the side naves." (the facade of S.Maria Novella)

2.3. Construction

The building was constructed largely without the supervision of Alberti. Chiu states that "...according to a dedication written by Fra Giovanni di Carlo, a friar at the church, to Cristoforo Landino, Alberti designed the marble inlay on the facade, and this was executed by Giovanni di Bertino, a mason skilled in this art" (Chiu 99). Various wooden models that were designed by Alberti were used by the masons with the details that they required for the construction. Furthermore, this method would have "...allowed Giovanni to employ different masons for each project, when he was ready to build. This may be a factor that has contributed to the uncertainty surrounding Alberti's role in Giovanni's projects." ( Chiu 97) the facade was therefore completed between 1458 and 1470 by Giovanni di Bertino, using Alberti's designs.

2.4. Significance

This facade is renowned for its highly stylized architectural beauty. As one commentator notes; "The decoration, in black and white marble, of the facade of Santa Maria Novella can perhaps be considered to be the most beautiful of all the Florentine churches." (the facade of S.Maria Novella) Alberti's achievement in continuing the project of this facade lies largely in his integration of the already existing medieval elements by "developing them along a classical design." (the facade of S.Maria Novella) Above all, the central significance of this facade is that it "…is a perfect example of the harmony found in the arts in the early Italian Renaissance." (the facade of S.Maria Novella) Alberti also contributed to the development of art as well as architecture. He wrote a number of books including a work entitled, on Painting. In general it is acknowledged that he was an influential figure in changing the direction of Italian Renaissance art. (the facade of S.Maria Novella)

3. St. Peter Basilica (1506 -- 1626)

3.1. Background

The Papal Basilica of Saint Peter in the Vatican commonly known as Saint Peter's Basilica is a Late Renaissance church located within Vatican City and has the largest interior of any Christian church in the world. Banister Fletcher, the renowned architectural historian, refers to it as "...The greatest of all churches of Christendom." (Fletcher 719) the symbolism and importance of this building relates to the burial site of Saint Peter, the chief apostle, who was buried in 64 a.D. The church on this site was completed in about 349 a.D. (St. Peter's Basilica)

However, by the 15th century the basilica was in poor repair, prompting Pope Nicolas V to initiate the restoration and enlargement of the church after plans by Bernardo Rossellino. (St. Peter's Basilica) Pope Julius II laid the first stone of the new basilica in 1506.

It is important to note at the outset that St. Peters Basilica is the end product of the labors of many architects and builders, rather than the result of the endeavors of a single person. As Bonde, Mark, and Robison (1993) write, "The first proposal to replace the old basilica came in the 1450s during the pontificate of Nicholas V." (Bonde, Mark and Robison 129) it incorporated the tomb where St. Peter's body was believed to be laid. The building took almost the entire sixteenth century and into the seventeenth century to complete.

The motivation behind the construction of this building can be traced to the desire of Pope Sixtus V for a new symbol to magnetize the Catholic world. To this end he consulted with the first main architect Domenico Fontana (1543 -- 1607). There was little positive outcome from this partnership in terms of building. The construction then became the task of Pope Julius who employed the architect Donato Bramante (1444 -- 1514). Bramante's plan for the structure was a Greek cross superimposed on a square with a central hemispherical dome supported on four massive piers. He experimented with Roman concrete for the piers and arches (Nuttgens 184). The first problem he encountered was an inability to move St. Peter's tomb. As a result, Bramante's church had to be grafted onto the earlier Constantinian basilica "by sacrificing one of the apsed arms of the cross… to the east." (Kostof 503)

3.2. Design

Pope Julius' ideas to create the most important building in Christendom led to a competition and it was the design of Donato Bramante that was selected. This design was based on the image of a Greek cross, which featured a large central dome surrounded by smaller domes. (St. Peter's Basilica) the design was intended to symbolize divine perfection. (Steiger) in more detail, Bramante's design was praised for various aspects; such as the top of his Corinthian columns. ( Steiger) Furthermore, in vaulting he "...invented a method of construction using a framework of stout beams, on which his friezes and foliage decoration were carved and then covered with castings in gypsum." ( Steiger)

As noted, the design of the building was influenced by a number of architects. For example, Pope Leo X appointed the painter Raphael to the post of chief architect. However, as Steiger notes; "For several years Popes and architects succeeded each other with little effect & #8230;" (Steiger)

The most significant architect and designer to complete the building was Michelangelo, who was appointed as chief architect in 1547. Michelangelo was 71 years of age at the time and remained as chief architect until his death. In terms of design he retained the Greek cross and the central dome from Bramante's original design. His design was however more compact and smaller in dimension than Brabante. He also "...unified the isolated parts into a perfectly connected whole, with details better scaled to a colossal interior 450 feet long and 450 feet wide." ( Steiger) Furthermore, he proposed a portico of 14 free-standing columns at the end of the eastern arm. These columns would be almost 100 feet high and 7 feet in diameter.

Figure: Michelangelo's Design

( Source: http://www.concreteconstruction.net/images/St.%20Peter's%20Basilica_%20Climax%20Building%20of%20the%20Renaissance_tcm45-348184.pdf)

Central to his design was the dome. It was designed as two shells and was intended to be higher and lighter than the dome proposed by Branante. Brabante had proposed a single shell design. When Michelangelo died the building was largely complete. However, the eastern arm of the Greek cross as well as the dome above the cylindrical drum was not entirely finished. (Steger) the dome was subsequently completed by Giacoma Della Porta and Domenico Fontana in 1587-90. (Steiger)

There were a number of architectural changes which were required to complete the construction. Modemo extended the eastern arm of the cross in order to increase the interior space. (Steiger) Other additions were made to the original design. These included "… the free-standing elliptical Colonnades that encircle the Piazza San Pietro." (Steiger)

3.3. Construction

The construction of this building took decades to complete. The actual historical statistics show that the construction from inception to its final completion took a total of 176 years, from 1450 to 1626 AD. As might be expected, the cost of such an important construction was enormous. (Basilica of St. Peter)

In terms of construction the basilica's dome is the world's largest measuring 42m in diameter and reaching 138 meter high. The interior, which includes 45 altars, was decorated by a number of famous artists: for example, the Pieta by Michelangelo and the papal altar by Bernini. (St. Peter's Basilica) the proportions of the building are as follows: height of the nave, 151.5 feet; width of the same at the entrance, 90.2 feet; at the tribune, 78.7 feet; length of the transepts in interior, 451 feet; entire length of the basilica including the vestibule, 693.8 feet. The measurements of the interior diameter of the dome vary somewhat, being generally computed at 137.7 feet, exceeding the dome of the Pantheon by a span of 4.9 feet. The surface area of St. Peter's is 163,182.2 sq. feet. (Basilica of St. Peter)

Among the many innovations that took place in the construction process was the introduction of movable scaffolding for centering the arches. ( Steiger)

This construction involved as great number of workmen and artisans as well as master craftsmen and Brabante was recognized for his management of the workforce that was employed in the construction. It should also be noted that Bramante revived a concrete mixture for the friezes and the cornices previously used by Roman builders. Concrete, which is the equivalent of contemporary reinforcement concrete, was used by Michelangelo to construct the dome. (Vatican researchers examine construction of St. Peter's Basilica dome)

3.4. Significance

James Lees-Milne describes Saint Peter's Basilica as "a church with a unique position in the Christian world." (Lees-Milne 12) the significance of the church is largely due its symbolic importance as the burial site of Saint Peter, one of the twelve apostles of Jesus. Its religious significance also includes the fact that is an important place of pilgrimage with many historical associations; it is also associated with many famous architects and artists, such as Michelangelo.

4. La Rotonda (1567 -- 1591)

4.1. Background

This construction of Villa Almerico-Capra, or Villa Capra, also known as the Rotonda was begun in 1550. This Renaissance villa outside Vicenza was designed by Andrea Palladio. This was one of more than twenty villas designed by Palladio. (Villa Almerico-Capra) the construction is renowned as a classic of the Pantheonic type, with its symmetrical quartet design. (Villa Capra, or Villa Rotund). It is also included in the UNESCO list of World Heritage Sites.