150 
geography of coal. 
the magazines of future enterprise and im¬ 
provement. 
North America possesses most valuable 
districts of coal from the tropics to the re¬ 
gion of perpetual snow. An inexhaustible 
supply is partially explored in the United 
States. The coal measures of British North 
America are also of great extent and rich¬ 
ness. 
In Europe, from the borders of the Black 
Sea^ from several places in Southern Russia, 
from the South of France, Spain, Bohemia, 
Saxony, Belgium, Northern' France, and 
Sweden, and from many other localities, 
this useful material is procured, and es¬ 
pecially from the British Isles. In sev en- 
teen counties of Ireland, in the greater part 
of the Lowlands of Scotland, in about 
sixteen distinct districts in England, col¬ 
lieries have been successfully established. 
The mode in which the mineral occurs is 
the same in all places, namely, in layers 
alternating with claystone or sandstones. 
These layers or beds are inclined at vari¬ 
ous angles to the horizon, in some instances 
as in the neighbourhood of Bristol, the 
