On the Building Materials used hy the Romans. 251 



used in the angles of houses, they seem generally to have intro- 

 duced bricks, and sometimes stones of a rectangular shape. 

 There are several beautiful specimens of this reticulated work 

 at Rome ; the gardens of Sallust under the Quirinal, and the 

 palace of Maecenas, may be mentioned as worthy of inspection. 

 In both these, you see this net-work promiscuously used with 

 bricks, regarding which we shall now make a few observations. 



The Opus lateritium or brick- work, began to come into ge- 

 neral use in the time of Augustus, and maintained its ground to 

 the fall of the empire ; it was nearly equal in strength to the 

 massive stone-work which was originally employed. There 

 were many changes, during this long period, in regard to the 

 form of the bricks, and the quantity of cement. In the reign of 

 Augustus, they were generally made of a red earth, of a tri- 

 angular form, and about an inch in thickness, as may be seen at 

 the gardens of Sallust, at the palace of Maecenas, under the Es- 

 quiline, and at the palace of Augustus on the Palatine. Under 

 Tiberius, the earth was of a deeper red or yellowish, as is proved 

 by the praetorian camp without the Porta Pia ; and in the time 

 of Nero, they mixed the yellow and red bricks in their build- 

 ings, as the aqueduct near the Porta Maggiore shews. They are 

 much smaller than those of Augustus and Tiberius, and very 

 little cement seems to have been placed between them. There 

 are some other remains, in different parts of Rome, that seem to 

 be of the same age and construction. Of the brick constructions 

 of the time of Vespasian and his sons, we have some magnificent 

 specimens in the amphitheatre of Flavins, the baths of Titus on 

 the Esquiline, and the villa of Domitian. The two former ap- 

 proach nearer the construction of Augustus, and the latter re- 

 sembles the brick-work of the palace of Maecenas. The edifi- 

 ces built in the reigns of Trajan, Adrian, and the Antonines, 

 exhibit the same construction, and though the bath%of Cara- 

 calla'are evidently deficient in good taste and beauty of design, yet 

 the brick-work is nearly equal to that of the best times. After 

 this there was a rapid decline in every thing connected with ar- 

 chitecture, and even the brick-work did not maintain its original 

 solidity. They no longer attempted to make them equal in 

 size, and they introduced large portions of cement, which tend- 

 ed much to weaken the strength of the walls. From Caracalla 



