These professionals had no theoretical training in architecture but had much practical knowledge, acquired on the construction sites. Among these professionals who created notable architectural designs is Manuel Ferreira Jácome, master stonemason, author of the São Pedro dos Clérigos Co-Cathedral. In Minas Gerais the presence of these masters was very striking and included names such as José Pereira dos Santos, José Pereira Arouca and Francisco de Lima Cerqueira, the latter responsible for the Saint Francis of Assisi Church in São João del-Rei. There were also designers who were not builders. An important example was Antônio Pereira de Sousa Calheiros, who was a doctor in law but designed the Rosary Churches in Ouro Preto and in Mariana. Luís da Cunha Meneses, colonial governor, designed the monumental City Council House and Jail of Ouro Preto. It is also important to mention Antônio Francisco Lisboa, Aleijadinho, who was primarily a sculptor but also author of important architectural projects. Techniques and materials Walls Initially, the colonial architecture used the techniques of rammed earth and wattle and daub, of quick construction and using abundant materials in the colony: clay and wood. Soon stonemasonry or adobe bricks were also adopted to raise walls, which allowed the construction of larger structures and the inclusion of woodwork for floors and ceilings. Wattle and daub, also called "taipa de sebe", "taipa de mão", "taipa de sopapo", or "barro armado", was one of the most used building systems in the colonial period. This was due to its low cost, since all of its required materials are natural, as well as its good resistance and durability. It was well known by the indigenous and African people, and its greatest incidence was in the areas that correspond to the current Northeast and Southeast regions. Its purest version has as its main structure wooden pieces composed of upper horizontal pieces (frechais), lower horizontal pieces (baldrames), and vertical pieces (esteios). The pieces are joined to form a weft, tied by silk, linen, hemp, or buriti cords. Finally, the clay is thrown on top. One system, similar to wattle and daub is the timber framing, common in the southern region, which, however, uses masonry for the fence. Another widely used system, especially for internal partitions is the tabique, which consists of a structure of wooden beams covered by boards. It is a system of great ease and simplicity in its execution. For the systems, the