172 EFFECTS of HEAT 
and I ftill believe, that yaft torrents, of depth fufficient to over- 
top our mountains, have {wept along the furface of the earth, 
excavating vallies, undermining mountains, and carrying away 
whatever was unable to refift fuch powerful corrofion. If fuch 
agents have been at work in the Alps, it is difficult to conceive 
that our countries fhould have been fpared. I made it therefore 
my bufinefs to fearch for traces of fimilar operations here. I was. 
not long in difcovering fuch in great abundance ; and, with the 
help of feveral of my friends, I have traced the indications of 
vaft torrents in this neighbourhood, as obvious as thofe I 
formerly faw on Saleve and Jura. Since I announced my opi- 
nion on this fubject, in a note fubjoined to my paper on Whin- 
ftone and Lava, publifhed in the fifth volume of the Tran/~ 
actions of this Society, I have met with many confirmations. 
of thefe views. The moft important of thefe are derived from 
the teftimony of my friend Lord SeLkrrx, who has lately 
met with a feries of fimilar facts in North America. 
Ir would be difficult to compute the effects of fuch an agent ; 
but if, by means of it, or of any other caufe, the whole mafs. 
of fecondary ftrata, in great tracts of country, has been remo- 
ved from above the primary, the weight of that mafs alone muft 
have been fufficient to fulfil all the conditions of the Huttonian 
Theory, without having recourfe to the preflure of the fea. But 
when the two preflures were combined, how great muft have 
been their united ftrength ! 
We are authorifed to fuppofe, that the materials of our ftrata, 
in this fituation, underwent the action of fire, For volcanoes 
have burnt long before the earlieft times recorded in hiftory, as 
appears by the magnitude of fome volcanic mountains; and it 
can fcarcely be doubted, that their fire has acted without any. 
material ceflation ever fince the furface of our globe acquired its 
prefent. 
