On the Building Materials used by the Romans, S4T 



those on the shore have entirely disappeared, and left scarce a 

 vestige behind them. On examining these foundations, it is 

 found that they consist of this sort of cement, bricks, and some- 

 times pieces of tuffa. The sand from the sea and river was 

 never employed when the other sort could be found, and the 

 same observation maybe made regarding gravel (glarea). The 

 cement, according to Vitruvius, was composed of three parts of 

 pit sand and one of limestone, or rather of two parts of river 

 or sea sand, and one of lime. They generally added a third part 

 of pounded shell to correct the defects of the sand, and to ren- 

 der the cement more firm and tenacious. 



Clay was employed in the formation of their bricks, and must 

 have been in great request in Rome, as their buildings are chief- 

 ly composed of this material. We are told by Vitruvius that, 

 in his time, the bricks were dried by the rays of the sun, and 

 he enters into a minute description of the method which they 

 employed ; in the ruins, however, existing at Rome, we observe 

 only bricks baked by artificial fire. On an attentive examina- 

 tion of those found in Rome and Pompeii, we discover that the 

 clay which they used was generally of two sorts, yellow and 

 red, and that they mixed with it tufFa dust to render it more 

 compact. Their size differs according to the use which was made 

 of them, and the time they were formed. The bricks employed 

 in courts are generally triangular ; those which we call tiles, and 

 which served to bind together the roof to the entire mass of the 

 wall, are a foot and a half square ; and those which were used 

 for arches are quadrilateral, and are a foot and a half long and 

 half a foot broad. Allthe ancient bricks are much finer in the 

 grain, and are easily distinguished from those of the present day. 



The stones which were employed in the buildings of ancient 

 Rome, are the following : tuffa, which Vitruvius calls lapides 

 rubri; peperino, or lapis albanus; travertino, or lapis tiburti- 

 nus; silex, and pumice-stone. The first four are found in the 

 foundations and outer facings of the buildings, as well as in the 

 internal construction of the walls and vaults ; the silex was only 

 employed in the pavement of the streets, and the interior masses 

 of the wall; the pumice-stone was particularly used in vaults 

 from its lightness. Tuffa is found in every part of the country 

 round Rome ; and the ancient quarries, alluded to by Strabo, 



