The coals of commerce acquire names by which they are widely known, and upon which their reputations stand. These names are not geological titles; and coal samples having the same name may, and usually do, come from different mines and even from different horizons. Many analyses and physical tests are made for various industrial purposes from samples taken from the railroad cars, after the latter have reached their destinations.
Proceedings of the Iowa Academy of Sciences
©1900 Iowa Academy of Science, Inc.
Keyes, Charles R.
"Names of Coals West of the Mississippi River,"
Proceedings of the Iowa Academy of Science, 8(1), 128-137.
Available at: https://scholarworks.uni.edu/pias/vol8/iss1/19