16 



"The Materials Used in the Building of Ancient Rome, and 

 their Geological Origin." 



Dr. E. J. Miles, (Hon. Librarian of the British and 

 American Archaeological Society of Rome.) 

 Read (by Mr. C. F. Dennet, in the absence of Dr. Miles), JunelOlh, 1S86. 



The author first glanced at the topography of Rome and de- 

 scribed the neighbourhood as seen from the flat roof of the Villa 

 Melini. The more prominent objects were noted, and the 

 geological formations to which they belonged. The greater por- 

 tion of these, except the most ancient were represented. Thus 

 the Umbrian and Sabine mountains belonged to the Jurassic, the 

 Corniculean Hills to the Lias ; the Volscian ranges to the Upper 

 Cretaceous. The Tertiaries, early and late, were found in several 

 places. Volcanic rocks were important and abundant in several 

 localities. A volcanic tufa was much used in early times. It may 

 still be seen in the fragments left of the primitive wall of Romulus. 

 The catacombs are also hollowed out in a soft tufa. Basaltic lavas 

 are also largely developed in the neighbourhood of Rome, and 

 have been much used for paving the ancient roads. A singular 

 volcanic conglomerate called peperino was ordered by Nero to be 

 alone used in the rebuilding of the city. Travertine, an aqueous 

 deposit of carbonate of lime, was largely used in Roman buildings. 

 The Colosseum is mainly constructed of it. The mortar owes its 

 hardness and durability to pozzolano, a volcanic dust or sand used 

 in its composition. Kiln-burnt bricks are first found in a build- 

 ing dating from 44 B.C. Imperial Rome gathered the splendid 

 marbles of its temples and palaces, from all quarters of the world. 

 Many of these were ennumerated, also the chief localities whence 

 they were obtained. The most beautiful ones came from Greece 

 and Egypt. Numidia supplied the glowing giallo antico, Phrygia 

 the peacock variety, and the island of Chios that known as 

 Africano. Dr. Miles also described several of the serpentines, 

 granites and porphyries more frequently met with among the 

 rnsns of Rome, and indicated the chief sources of them. 



