162 ' The Volcanic Rocks of 



difcion of their framework, and the quantity of soil around 

 their base, 



AGE. 



A year before I entered Rome a good and learned Irish 

 priest had made a notable discovery there. His duties were 

 at the San Clemente's Church, an edifice eight hundred years 

 old, which you enter by descending steps. He had the good 

 fortune to discover that this rested upon a much more 

 ancient church of St. Clement, erected in the Imperial times. 

 Further investigation led to the announcement that this 

 primitive Christian house of prayer was raised upon a 

 heathen fane, of vast proportions, whose walls stand there 

 with blocks of volcanic Peperino eighteen feet in length. 

 This is a story of Time. 



Entering, then, upon the Age of the Volcanic Fields of 

 Rome and Victoria, we must have recourse to some such 

 process of descent as with that of San Clemente. We must 

 gb down to the Past. 



We have more data for estimating the age of the volcanic 

 monuments of Rome than of Victoria. Human appreciation 

 of time is always insignificant. While standing beside the 

 towering Coliseum, or keeping pace with the ghostly tread 

 of legions on the Appian Way, the awe of distant years 

 came over me. But long before Eternal Rome began her 

 v/ondrous life, the fires that raised the soil were quenched, 

 and herbs and flowers had healed the wounds of strife. It 

 was fitting that the city which set the world in flames 

 should rest upon flaming fields. 



A few minutes before the iron horse carries the traveller 

 along the tufa plains into Rome, a low range of hills may 

 be seen. A railway cutting exposed a part of the diluvial 

 base, and brought to our view some of the original inha^ 

 bitants of the country. Bones of the elephant, hippopotamus, 

 and rhinoceros, rolled out of the post Tertiary marls and 

 sand. The blue-clay pits tell the same tale at the rear of 

 the Papal Palace. The red Tufa Lithoide is near this 

 formation. Over the tufa, and forming the summit of 

 Monte Mario, are the Tertiary Mosaic beds of the Pliocene 

 order, containing three hundred species of shells. Upon 

 the celebrated Pincian Hill the remains of elephants have 

 been discovered under a bed of travertin. Forty feet of 

 fresh- water deposits lie on the summit of the hills. We 

 have evidence of the existence of fresh- water lakes between 



