18 Account of the 



the tomb of Horatia l)eing constructed of Saxum quadratnm *, 

 and when Vitruviusf, speaking of certain monuments near Rome, 

 says, that some were built of marble and others lapidibus quadra- 

 tis, they are, it is conceived, to be understood to mean this stony 

 tufa. Indeed the passage of Vitruvius makes it very probable ; 

 for had he alluded to the cutting of the stone by the mason, 

 would he not have spoken of the marble being squared also ? 

 The younger PHny J, speaking of the aqueducts of Nicomedia, 

 perhaps refers to a stone of this description, for many parts of 

 Asia Minor are volcanic §. This stone was also called by the 

 ancients tophus ruber ^ a term made use of by Vitruvius |1 in 

 speaking of that of Campania; and the tophus niger was pro- 

 bably the peperino, which is used in many of the buildings of 

 Pompeii. They also speak of sa/vum rubrum, and saxum 

 rubrum quadratum. Strabo uses the former phrase, and Vi- 

 truvius both, and also mentions the rubrcB lapidicince^ of 

 the environs of Rome. In the Flaminian Way, there was a 

 place called ad saxa rubra^ mentioned by Livy**, Cicero-(-f, 

 Tacitusjj, and Festus Pompeius, and which still preserves 



* " Horatiae sepulcrum, quo loco conruerat icta, constructum est saxo 

 quadrato." — Lib. i. 26. 



■{• *' Id autem licet animadvertere etiam de nonnuUis monumentis, quae 

 circa urbem facta sunt e marmore seu lapidibus quadratis ;" and a little far- 

 ther on, he speaks of building walls " ex ruhro saxo quadrato, aut ex testa, 

 aut silicibus ordinariis." — I^ib. ii. c. 7* 



:J: " Manent adhuc paucissimi arcus, possunt et erigi quidam lapide quad- 

 rato." — Lib. X. ep. 46. 



§ Vitruvius mentions that pumice is found in Mysia, which is not very 

 far distant from Nicomedia: — " Pumex — non in omnibus locis nascitur, nisi 

 ■circum ^Etnam, et collibus Mysiae, qui a Graecis x.KTa.x.iKa.v/^ivoi nominantur." 

 — Lib. ii. c. 6. 



II " Sunt etiam alia genera plura, uti in Campania ruber et niger tophus.*' 



Lib. ii. 7' 



% Lib. ii. c. 7. 



•• Speaking of the battle of the Cremera, and the retreat of the Veientes : 

 " Ita, fusi retro ad sojea rubra^ (ibi castra habebant), pacem supplices petunt." 

 — Lib. ii. cap. 49. 



ft Phil. ii. 31. 



Xt " Antonius per Flaminiamad Saxa rubral multo jam noctis, serum auxi- 

 lium venit." — Hist. L. iii. c. 79. • 



