214 VALLEYS NOT EXCAVATED BY CAUSES IN ACTION. 
and not to burst their barriers ; and that whatever antediluvian lakes 
and inland seas may have formerly existed, the gorges and defiles by 
which their waters were discharged can be referred to no physical 
cause at present in action, but were excavated by some extraneous and 
more mighty power than the waters of the lakes themselves; and 
“ where,” says he, “ is such a power to be found, but in the agency of 
the diluvian waters ?” 
