Tim O' writes - Are there any other coal classifications besides bituminous and anthracite?
From a 1930 Fireman's manual:
super anthracite - very hard pure carbon with very little impurities.
sub lignite - low carbon, high impurities.
There was additional information given on each type, carbon content and impurities, moisture content.
Coke was listed as coked sub bituminous.
Sales prices of all coals were based on BTU content.
Jim Dick - St. Paul