The quasi-reticulate work belongs to the early years of the Roman colony. In appearance it lies between rubble and reticulate work, differing from the latter in that the small blocks are less carefully finished and are laid with less regularity. The material is generally lava, but tufa and limestone are also found. The corners and doorposts are of brick, or of brick-shaped blocks of tufa or limestone ([Fig. 11]).
Ashlar work, of carefully hewn oblong blocks laid in courses, is found in the older portions of the city wall ([Fig. 109]) and in the walls of the Greek temple in the Forum Triangulare; it was used otherwise only for the fronts of houses ([Fig. 10]). The material in the earliest times was Sarno limestone, later gray tufa. With the coming of the Roman colony ashlar work went out of use, even for the corners of houses and doorposts.
In the construction of columns and many architraves large blocks were used. Previous to the time of the Roman colony these were of gray tufa, or, in rare instances, of limestone; a coating of white stucco was laid on the surface. From the advent of the colony to the time of the Early Empire, the whitish limestone was used; after that, Carrara marble.
Bearing in mind the styles of construction just described, we may now turn to the architectural history of Pompeii, which, as we shall see, falls naturally into six periods.
The first period is that to which the Doric temple in the Forum Triangulare and the city walls belong. From the style of the temple, we may safely conclude that it was built in the sixth century B.C.; the evidence is too scanty to enable us definitely to fix the date of the walls. The building materials used were the Sarno limestone and gray tufa.
The second period may be designated as the Period of the Limestone Atriums, so characterized from the peculiar construction of a number of houses found in different parts of the city. On the side facing the street these houses have walls of ashlar work of Sarno limestone ([Fig. 10]), but the inner walls are of limestone framework ([Fig. 9]).
Fig. 10.—Façade of Sarno limestone, house of the Surgeon.
Almost no ornamental forms belonging to this period have come down to us; so far only a single column has been found, built into the wall of a house. It is of the Doric style, and once formed part of a portico that ran along the west side of the small open space at the northwest corner of Stabian and Nola streets; it is thus the sole remnant of a public building. In the only complete house that has survived from this period, the house of the Surgeon, there was a portico in front of the garden, but the roof was supported by square pillars, not by columns. There is no trace of wall painting.