COMMON COAL. 151 
Some kinds of coal are laminar, and others compact. They 
in general burn freely, with a bituminous odour, and leave a 
considerable residuum. 
This invaluable mineral is found in beds, or strata, 
frequently betwixt clay slate (257) and sandstone (267), 
and seldom betwixt those of limestone (140). It 
chiefly occurs in the northern hemisphere, particularly 
in countries which lie nearly in the same latitudes with 
Great Britain ; in Siberia, Germany, Sweden, France, 
Canada, and Newfoundland ; and in some of the north- 
ern parts of China. It is stated to be abundant in New 
Holland; but we have no distinct account of coal in the 
continent of Africa. No fewer than seventy different 
kinds of coals are brought to ihe London market, the 
value and prices of which greatly differ. Of these the 
coals called Watts-end, from the name of the pit, near 
Newcastle, whence they are obtained, usually bear the 
highest price. 
218. COMMON COAL, or PIT COAL, is of black 
colour, and has generally a slaty structure and foliated tex- 
ture. 
When handled it stains the fingers; and when burnt it cakes 
more or less during combustion. Its component parts are 
usually charcoal (48) and bitumen (216), zoith a small portion 
of day, and sometimes zoith pyrites, or sulphat of iron (236). 
What is called slaty coal contains a greater portion of clay 
than other kinds. 
Some foreign writers have ascribed the great wealth 
possessed by this country to the coals which are here 
produced in such abundance, and which facilitate, in a 
very essential degree, nearly all its manufactures, and, 
consequently are a means of promoting its commerce 
to an extent which is possessed by few other countries. 
All our great manufacturing towns, Birmingham, Shef- 
field, Leeds, Glasgow, &c. are situated either in the 
midst of coal districts, or in places to which coals are 
conveyed, with little expense, by canal carriage. 
Coals are principally obtained from the neighbour- 
hood of Newcastle-upon-Tyrie, Sunderland, and White- 
