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 And 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 Tihertin. 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 saysf , 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. 
Voyages Physiques et Lythologiques dans la Campanie, par Scipion Breislak, tom. li. 
p. 262 . 
