Domes built in the 19th century benefited from more efficient techniques for iron production and steel production, as well as advances in structural analysis. Metal-framed domes of the 19th century often imitated earlier masonry dome designs in a variety of styles, especially in church architecture, but were also used to create glass domes over shopping arcades and hothouses, domes over locomotive sheds and exhibition halls, and domes larger than any others in the world. The variety of domed buildings, such as parliaments and capitol buildings, gasometers, observatories, libraries, and churches, were enabled by the use of reinforced concrete ribs, lightweight papier-mâché, and triangulated framing.
Developments Materials New production techniques allowed for cast iron and wrought iron to be produced both in larger quantities and at relatively low prices during the Industrial Revolution. Most iron domes were built with curved iron ribs arranged radially from the top of the dome to a ring at the base. The material of choice for domes changed over the course of the 19th century from cast iron to wrought iron to steel. Excluding domes that simply imitated multi-shell masonry, the century's chief development of the simple domed form may be metal-framed domes such as the circular dome of Halle au Blé in Paris and the elliptical dome of the Royal Albert Hall in London.
The practice of building rotating domes for housing large telescopes became popular in the 19th century, with early examples using papier-mâché to minimize weight.
Beginning in the late 19th century, the Guastavino family, a father and son team who worked on the eastern seaboard of the United States, further developed the masonry dome. They perfected a traditional Spanish and Italian technique for light, center-less vaulting using layers of tiles in fast-setting cement set flat against the surface of the curve, rather than perpendicular to it. The father, Rafael Guastavino, innovated with the use of Portland cement as the mortar, rather than the traditional lime and gypsum mortars, which allowed mild steel bar to be used to counteract tension forces.
Although domes made entirely from reinforced concrete were not built before 1900, the church of Saint-Jean-de-Montmartre was designed by Anatole de Baudot with a small brick shell dome with reinforced concrete ribs. in Munich, Germany, was built between 1894 and 1897 with a dome of two lightweight concrete shells, using reinforcing rings only in the underlying octagonal tambour. The hemispherical inner dome is 15 cm thick with eight ribs on its outer surface increasing that thickness to 29 cm. The outer octagonal cloister vault is 11.8 meters wide and 16 cm thick. An artificial stone called was used as a porous aggregate. Neither dome included reinforcement, although iron bars have been detected at irregular distances in the outer dome that may have been part of the formwork needed for the building process, and which may act as partial reinforcement. Other concrete domes at this time included a music pavilion in Hoppegarten (1887–1888), the Monier-dome of the mausoleum of Emperor Frederick III in Potsdam (1889), and a dome above the foyer of the Brunner banking house in Brussels (1892–1895).
Structure Proportional rules for an arch's thickness to span ratio were developed during the 19th century, based on catenary shape changes in response to weight loads, and these were applied to the vertical forces in domes. The first studies on domes' limit thickness were published in 1855 by Kobell. Mathematical analysis of domes were published by Eytelwein (1808), (1823), Persy (1834), Kobell (1855), Scheffler (1857), and Michon (1857), but the methods were not used by architects and engineers. Edmund Beckett Denison, who had published a proof on the subject in 1871, wrote in a Domes article in the Ninth Edition of the Encyclopædia Britannica that the thickness to span ratio was lower for a dome than it was for an arch due to the more distributed loads of a dome. The first studies of collapse mechanisms for domes were published in 1877 by Beckett. Ideas on linear elasticity were formalized in the 19th century. The first graphical analysis of domes was published in 1879 by Wittmann, allowing the line of thrust to be determined, and it was used by other German authors. The 1878 graphical method by Henry Turner Eddy to calculate compressive and tensile hoop forces was applied to masonry domes of revolution in any form in 1881 by August Föppl and it was used in America beginning around 1900.
The span of the ancient Pantheon dome, although matched during the Renaissance, remained the largest in the world until the middle of the 19th century. The large domes of the 19th century included exhibition buildings and functional structures such as gasometers and locomotive sheds.
Domes made of radial trusses were analyzed with a "plane frame" approach, rather than considering three dimensions, until an 1863 Berlin gasometer dome design by engineer Johann Wilhelm Schwedler that became known as the "Schwedler dome". He published the theory behind five such domes and a structural calculation technique in 1866. Schwedler's work on these axially symmetric shells was expanded by August Föppl in 1892 to apply to "other shell-type truss frameworks". By the 1860s and 1870s, German and other European engineers began to treat iron domes as collections of short straight beams with hinged ends, resulting in light openwork structures. Other than in glasshouses, these structures were usually hidden behind ceilings. Dome types that used lengths of rolled steel with riveted joints included "Schwedler domes", "Zimmermann domes", "lattice domes", and "Schlink domes".
According to Irene Giustina, dome construction was one of the most challenging architectural problems until at least the end of the 19th century, due to a lack of knowledge about statics. Rafael Guastavino's use of the recent development of graphic statics enabled him to design and build inexpensive funicular domes with minimal thickness and no scaffolding. The vaults were typically 3 inches thick and workers, standing on the completed portions, used simple templates, wires, and strings to align their work.
Style The historicism of the 19th century led to many domes being re-translations of the great domes of the past, rather than further stylistic developments, especially in sacred architecture. The Neoclassical style popular at this time was challenged in the middle of the 19th century by a Gothic Revival in architecture, in what has been termed the "Battle of the Styles". This lasted from about 1840 to the beginning of the 20th century, with various styles within Classicism, such as Renaissance, Baroque, and Rococo revivals, also vying for popularity. The last three decades of this period included unusual combinations of these styles.
Religious and royal buildings The Royal Stables at Brighton Pavilion were designed by William Porden and built from 1804 to 1808 in an Orientalist style for the Prince of Wales. The circular courtyard of the stable block, in diameter, was domed with laminated timber and glass, evidently inspired by the similar dome over the Halle aux blés in Paris. The three-layer wooden ribs were supported horizontally by wooden purlins and iron chains. An oculus was covered by a lantern shaped as a coronet on the exterior. It was converted into a concert hall in 1934 and redecorated in an Art Deco style.
The rotunda dome of the Church of the Holy Sepulchre in Jerusalem was replaced from 1808 to 1810 after a fire and replaced again from 1868 to 1870. The dome completed in 1870 was a Russian design made with wrought iron arches.
Iron domes offered the lightness of timber construction along with incombustibility and higher strength, allowing for larger spans. Because domes themselves were relatively rare, the first examples made from iron date well after iron began to be used as a structural material. Iron was used in place of wood where fire resistance was a priority. In Russia, which had large supplies of iron, some of the earliest examples of the material's architectural use can be found. Andrey Voronikhin built a large wrought iron dome over Kazan Cathedral in Saint Petersburg. Built between 1806 and 1811, the outer dome of the cathedral was one of the earliest iron domes. The iron outer dome covers two masonry inner domes and is made of 15 mm thick sheets set end to end.
St. George's Church in Edinburgh was built from 1811 to 1814 by Robert Reid with a dome modeled after that of St. Paul's Cathedral. An early example of an iron dome in Britain is the fanciful iron-framed dome over the central building of the Royal Pavilion in Brighton, begun in 1815 by John Nash, the personal architect of King George IV. The dome was not one of the prominent onion domes but instead the dome-like structure of twelve cast iron ribs resting on cast iron columns over Henry Holland's earlier saloon. It was completed in 1818–1819.
The neoclassical Baltimore Basilica, designed by Benjamin Henry Latrobe like the Roman Pantheon for Bishop John Carroll, was begun in 1806 and dedicated in 1821, although the porch and towers would not be completed until the 1870s. An influence on the interior design may have been the Church of St. Mary in East Lulworth, England, where Bishop Carroll had been consecrated. The central dome is in diameter and above the nave floor. The onion domes over the two towers were built according to Latrobe's designs. The church was extended to the east by in 1890. Before initial construction of the church was completed, two other neoclassical domed churches would be built in Baltimore. The First Independent (Unitarian) Church by Maximilian Godefroy was begun in 1817 and covered the interior space with a shallow coffered dome on pendentives with an oculus at the center. To improve acoustics, the interior was modified. The First Baptist Church by Robert Mills, also known as "Old Red Top Church", was a domed cylindrical rotunda with a porch block and portico. The dome had a shallow exterior profile and its oculus was covered by a low lantern, called a monitor. It was completed in 1818 but demolished in 1878.
In 1828, the eastern crossing tower of Mainz Cathedral was rebuilt by Georg Moller with a wrought iron dome. The dome was made of flat iron sections and reinforced with ties that passed through the interior of the dome. Such dome reinforcement was one of the two established techniques, the other being the use of a combination of horizontal rings and vertical ribs. The span may have been about 27 meters. It was later removed in favor of the current structure.
The Altes Museum in Berlin, built in 1828 by Karl Schinkel, included a dome in its entrance hall inspired by the Roman Pantheon.
Large neoclassical domes include the Rotunda of Mosta in Malta, was completed in 1840 with a dome 38 meters wide, and San Carlo al Corso in Milan, completed in 1847 with a dome 32 meters wide.