THICKNESS OF COAL BEDS. O'il) 
I am relieved from the necessity of entering 
into details respecting the history of the Coal 
Fields of our own country, by the excellent 
summary of what is known upon this interesting 
subject, which has recently been given in a judi- 
cious and well selected anonymous publication, 
entitled The Histori/ and Description of Fossil 
Fuel, the Collieries, and Coal Trade of Great 
Britain, London, 1835. 
The most remarkable accumulations of this 
important vegetable production in England are 
in the Wolverhampton and Dudley Coal Field, 
(PI. 65, Fig. 1,) where there is a bed of coal, ten 
yards in thickness. The Scotch Coal field near 
Paisley presents ten beds, vrhose united thick- 
ness is one hundred feet. And the South Welsh 
Coal Basin (PL 65, Fig. 2,) contains, near Ponty- 
pool, twenty-three beds of coal, amounting toge- 
ther to ninety-three feet. 
In many Coal fields, the occurrence of rich 
beds of iron ore in the strata of slaty clay, that 
alternate with the beds of coal, has rendered the 
adjacent districts remarkable as the site of most 
important Iron foundries ; and these localities, 
as we have before stated, (p. 65,) usually present 
a further practical advantage, in having beneath 
the Coal and Iron ore, a substratum of Limestone, 
that supplies the third material required as a 
flux to reduce this ore to a metallic state. 
Our section, PI. Qb, Fig. 1, illustrates the re- 
(*tOL. M M 
