important centers such as Recife, Salvador and São Luís. Houses in Brazil were generally of stone masonry or taipa de pilão with partition walls of pau a pique, with the exception of Pernambuco, where the use of brick was more common. The stonemasonry, when it existed, was limited to the corners of the house. The first floor had a dirt floor, while the other floors had wooden plank floors. The first floor was used for commercial activities, storage, stables, and slave quarters, with a corridor leading to the back yard and a staircase leading to the upper floor. The second floor - the noble floor - was dedicated to housing. It was organized with a large hall facing the street, from which emerged a corridor with on each side small rooms without openings to the outside (alcoves). The profile of the windows was rectangular or arched, framed in wood or, more rarely, in stone. The noble floors could have balconies with iron railings. The upper windows could also be covered with mashrabiya or wooden lattices, while glass windows only became common in the late 18th century. The roofs were gable or hipped with eaves, sometimes with some discreet ornamentation such as a gentle curvature and pointed tiles at the corners of the roof. Urban houses of great nobility dating from the late 17th and early 18th centuries are common, for example, in Salvador, such as the Sete Candeeiros House, the Ferrão Palace, the Saldanha Palace, the Conde dos Arcos Palace, and the imposing Arcebispos House of the city, built between 1707 and 1715. In Bahia the urban palaces are characterized by doorways in lioz stone or local stone, decorated with reliefs, coats of arms, and volutes. The interiors could be decorated with coffered ceilings and Portuguese tiles. In Rio de Janeiro, an important example is the Governors' Palace (now Imperial Palace), built between 1738 and 1743. This palace, also decorated with Lioz shutters, was the first in Brazil to present windows with curved upper lintel, which soon after would be very common throughout the colony. Also in the hinterland farms some interesting manor houses survive. Some of great dimensions, such as the big house of the Freguesia Mill, in the Recôncavo Baiano region, although its architecture is in general quite simple, with a main building for the owner's residence and other annexes for the senzala, deposits for tools and food,