(Almost) forgotten knowledge

Study brings back a centuries-old technique to build in stone

DALTON ALMEIDA RAPHAELSan Miguel Fort, in Uruguay: eighteenth centuryDALTON ALMEIDA RAPHAEL

Before concrete, it was stone. Churches, government buildings, palaces, fortifications, monasteries, bridges, canals and everything else that had to be long lasting, all had stone in common as the main element of construction. Worked by master artisans to be fitted together one on top of the other, rocks gave shape to the arches and walls that commonly supported multi-storied structures without requiring any cement, iron or timber reinforcement. Many of these buildings are still standing today, hundreds of years after being built. The art and technique of thinking about, working with and piling up stones to compose a stable architectural system are called stereotomy (from the Greek stereos, solid, and tome, cutting) and were widely used in Brazil, brought here first by the Portuguese and then by the Spanish, Dutch and English. With the development of concrete and reinforced concrete, the technique fell completely into disuse at the turn of the twentieth century and seems to survive only in some books published in Europe. In Brazil, Dalton Almeida Raphael, a professor of descriptive geometry at the School of Fine Arts at the Federal University of Rio de Janeiro (UFRJ), has published a detailed study in which he analyses and sets out the system of stereotomy in Portuguese America.

DALTON ALMEIDA RAPHAELArchways of the Santa Cruz Fort in Niterói, Rio de Janeiro state, from the seventeenth centuryDALTON ALMEIDA RAPHAEL

Master builders basically used the experience of previous artisans when they were planning buildings in stone, which involved knowledge currently associated with mathematics, such as geometric constructions, also called geometric design, and subsequently descriptive geometry. Stereotomy was developed during early civilizations and used in Mesopotamia, Egypt, Greece and Rome, as well as in the Far East. “The projects were totally empirical in their organization and in the sizing of their structural elements,”  says Raphael, author of a PhD thesis on the subject. “Improved knowledge was undoubtedly inherited from the old  craft companies and was widely spread across the centuries.”  The technique is responsible for buildings that after a thousand years or more are so stable that they are still virtually intact today, such as the cathedrals of  Notre-Dame and Chartres, in France, or the Convent of Batalha, in Portugal, among many others.

Dalton Raphael studied buildings in Brazil where it was possible to analyze this method of construction, such as the military forts of San Miguel and Santa Teresa (now part of Uruguay), the São Bento Monastery and the Church of the Imperial Irmandade de Nossa Senhora da Glória do Outeiro in Rio de Janeiro, the Castle of the Torre de Garcia d’Ávila, in Bahia, the many hermitages in Minas Gerais and the Jesuit Missions in the south of the country. “But today it’s almost impossible to find anyone who knows the technique in practice, who knows how to cut stone and how to strike it correctly to make the most of it so that it fits perfectly,” says the researcher.

DALTON ALMEIDA RAPHAELArch of the São Pedro dos Clérigos Church, in Mariana Minas Gerais state, from the eighteenth centuryDALTON ALMEIDA RAPHAEL

The first Portuguese settlers in Brazil began building with wood and straw. However, from  the mid-sixteenth century to the end of the century, there were already buildings made out of stone. The Torre Castle, 80 km away from Salvador, started being built in 1551. Today, one can still see its structure, although the roof has collapsed. The Church of the Imperial Irmandade de Nossa Senhora da Glória, in Rio, inaugurated in 1739, is still standing and in one piece. It was there that Raphael defended his thesis in July 2009, while using a laser pointer to indicate the particularities of the place. “It’s a true stereotomy laboratory,”  says the chemist and science historian Carlos Alberto Filgueiras, Raphael’s supervisor at UFRJ and today back at the University where he started, the Federal University of Minas Gerais (UFMG).

Construction processes began to change with the arrival of the royal family in 1808. Because of the influence of Grandjean de Montigny, architect of the French Mission, a new esthetic appeared in Brazil in 1816. Towards the late nineteenth century, concrete and reinforced concrete became dominant, because it was easy to work with. Ever since, stereotomy has become an almost forgotten skill. “The study of this technique is interesting even for lay people because it shows how former architects worked when planning their buildings, before the modern studies of material resistance and stability of buildings,”  observes Filgueiras.