371 



clay-built, or wooden hovel, for a more durable and pleasant mansion. 

 Thus we see, man is driven by a predestined, and apparently cruel, 

 necessity, to the exercise of those powers, and the invention of those 

 arts, by which his happiness and welfare is promoted ; and is forced, 

 by a most salutary, but mysterious, influence to make his destined 

 advances in the progress of civilization. 



Thus we find that almost all the houses in the neighbourhood of 

 Matlock, and in some other parts of England, are built of this 

 kind of stone, which is found exceedingly durable. The mountain 

 of Tivoli, formed by this species of calcareous deposition, has fur- 

 nished, time out of mind, the greatest part of the stones which 

 have been used at Rome. This stone is usually called Travertin, a 

 corruption of the word Tibertin. The front of St. Peter's Church is 

 built with it; and the Colosseum, according to Misson*, is covered 

 all over with it. Count Stolberg also observes, that its upper part is 

 formed of a light porous stone. Breislak says-f-, at the foot of the 

 mountain of Tivoli, where the Anio enters the plain which reaches 

 to Rome, are the quarries of Travertin. Independently, he says, 

 of the immense quarries, dug by the ancients, there are others of 

 such a vast extent, as will be sufficient to supply the demand of a 

 great number of ages. 



Nor is this deposition, of stony matter confined to the surface, 

 since this petrifying process is likewise carried on. in immense ca- 

 verns, at some depth in the earth ; where immense quarries of stone 

 are thus formed, and laid up in store for man's future use. Through 

 the roofs of these caverns, the pellucid solution of carbonate of 

 lime filtrates, and deposits, from the moisture left of every falling 

 drop, the spar it contains : forming, by the growth of ages, innu- 

 merable stalactites, which depend, like icicles, from different parts 



* Misson's Travels, vol. ii. p. 66. 



t Voyages Physiques et Lythologiques dans la Campanie, par Scipion Breislak, torn. ii. 

 p. 262. 



