No. VI. — District of the Bay of Baja. 95 



If we descend to the sliore below these baths, we find the 

 Bay of Baja crowded with the ruins of villas, which once be- 

 longed to wealthy Romans, disputing with the waves the pos- 

 session of the bank *. Many of the Roman Emperors select- 

 ed this spot as their chosen retreat ; and, guided by the hand of 

 fancy and the records of classic antiquity, we may trace the 

 villas of Julius Caesar, Nero, and Adrian, of Pompey, Marius 

 and Hortensius. But here it is not our object to dwell on 

 these delightful and interesting associations. We would point 

 rather to a remarkable fact which these ruins present. Many 

 of them are built in the style of the opus reticulatum, in which 

 the lozenge-shaped pieces which invest the exterior of the wall 

 are formed, as usual, of the common stone of the country, 

 which is here the ordinary friable tufa f. They were im- 

 bedded in mortar formed of Pozzuolana of the finest descrip- 

 tion, — a cement which takes its name from this vicinity, and the 

 remarkable fact is, that where exposed to the water, the reti- 

 culated masses have, by long attrition, been washed out, while 

 the thin dividing portions of cement stand to this hour a 

 monument of its durability, and the masses of building present 

 the most curious honey-combed appearance. The Pozzuolana 

 is dug in the immediate neighbourhood, namely, just behind 

 the three temples at Baja, bearing the names of Venus, Diana, 

 and Mercury. It has there a pale grayish colour, considerably 

 differing from the brownish black dug near Naples, and the 

 deep red of the Campagna di Roma. To nothing have the 

 architectural remains of the ancient Romans been so much in- 

 debted for their durability as to this invaluable production of 

 volcanic countries ; and a want of attention to this circumstance 

 has superinduced the most unfounded supposition regarding 

 the means employed by the Romans to harden their mortar, 

 at least when applied to buildings in Italy. 



By examining merely theoretical descriptions of the Pozzuo- 

 lana, vve should not perhaps find it easy to separate it from the 

 ordinary tufaceous formations round Naples, with which indeed 

 it has been too much confused, which might lead readers to 

 imagine that the hill of Pausilipo was composed of it, and that 



* See Hor. Carm. ii. 18. f See this Journal, No. xvii. p 30. 



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