17 
The expansions of the crust of the earth which occurred at 
this period, appear to have been much more abrupt and 
violent than any that either preceded or succeeded them. 
The total thickness of the expanded earths crust, above 
the old red sandstone to the permian inclusive, is about as 
follows : — 
800 yards mountain limestone. 
1,000 „ millstone grit. 
1,500 „ coal measures. 
3,300 „ 
100 „ permian. 
3,400 „ or about two miles. 
Proceeding upwards there is the new red sandstone upon 
which Doncaster stands. I may remark that the ordnance 
survey is mapping down all the beds before-named in the 
permian system, and have divided the new red sandstone 
into — 1. Lower Bunter sandstone ; 2. Middle Bunter ; and 
3. Lower Keuper ; upon which is the fourth member of the 
series — 4. Upper Keuper. 
Spread over so immense a space in England the new red 
sandstone system never rises to elevations above 800 feet, a 
circumstance, remarks Professor Phillips, due to some law of 
physical geology yet unexplained. We can only conjecture 
that it is connected with the repose of the subterranean 
forces, which prevailed after the violent commotions of 
the coal strata over nearly all Europe till the tertiary 
epoch. " The red sandstone area," says he, " seems to be 
" like (which no doubt it really is) the large and uplifted 
" bed of a shallow sea, full of rocky islands, and bounded 
" by bold promontories." 
It was upon this ancient sea bottom, studded with lakes, 
that we find the remains of those gigantic reptiles beginning 
to appear in the lias, about which Hugh Miller says, " And 
B 
