( 246 ) 



On the Materials which the Romans employed in their Build- 

 ings. By Mr C. T. Ramage, A. M. of Naples. Commu- 

 nicated by the Author. 



A HE materials which were used in the erection of the vari- 

 ous edifices, which add so much interest to the ancient city of 

 Rome, may be ranged under two great classes. The first con- 

 sists of the common materials for building, which were found 

 in the immediate neighbourhood of the city, such as limestone, 

 pozzolana, clay, and silex ; the second of those which were 

 brought from a distance, white and coloured marbles, granites, 

 and porphyries. 



Their mortar was made, as it is at present, either from com- 

 mon limestone, or from a stone which Vitruvius calls silex, and 

 which may perhaps correspond with our compact calcareous 

 limestone. That which was obtained from the last, was em- 

 ployed in the construction of walls, while the other was used as 

 plaster. This mortar was mixed either with Arena fossica^ 

 sand dug from pits, or Arena Jluviatica and marina^ from rivers 

 and the sea. Of the first they had several sorts, black, white, 

 and red, together with that to which we give the general name 

 of pozzolana^ The vicinity of Rome abounds with this last sort, 

 and the inhabitants still use it for the same purpose. The 

 place from which the sand was dug, was called Arenarium, and 

 these excavations have no doubt given rise to the catacombs in 

 Rome. The colour of this pozzolana is by no means uniform, 

 for it is sometimes found red, sometimes purple, and sometimes 

 the colour of tobacco. Its name is derived from Pulvis puteo- 

 lanus, because it was originally found in great quantities in the 

 neighbourhood of Pozzuoli, near Naples. It was particularly 

 used for buildings under water, because it resisted the influence 

 of that element, and acquired such a consistency as to form a 

 solid mass of stone and brick. A proof of this is found in the 

 ruins of the harbour of Antium, and of the mole of Pozzuoli, 

 which is called the bridge of Calligula^ though it must date its 

 origin long before the reign of that emperor. It is curious to 

 observe, that on the shore of Baiae, where Horace accuses the 

 Romans of attempting to deprive Neptune of part of his terri- 

 tory, the foundations of the houses in the sea still remain, while 



