|New York World's Fair State of Pennsylvania Replica of Independence Hall housing Giant Anthracite Wall|
|New York World's Fair Giant Anthracite Hard Coal Wall in the State of Pennsylvania Exhibit|
|New York World's Fair Anthracite Hard Coal Exhibit in Home Centre Building|
|New York World's Fair Automatic Anthracite Stokers for home heating in Home Centre Building|
The four postcards above are from the State of Pennsylvania exhibits at the 1939-1940 New Work World's Fair. The exhibits featured Anthracite Coal, an important Pennsylvania product. Anthracite is a hard coal that differs from ordinary bituminous coal by its greater hardness, its higher relative density, and luster.
Here are some facts about Anthracite formation gleaned from the subtitles on a 1920s silent film video, Anthracite Coal Mining circa 1920 (this video is informative but somewhat tedious):
- Different from bituminous, which occurs in level beds, anthracite is found in folded and twisted strata.
- The coal beds are but the remains of ancient forests.
- As the dense vegetation decayed it made a carpet of humus hundreds of feet thick.
- The land sank and water covered the remains of the forest. Silt and sand slowly settled down.
- Tremendous pressure from above packed the mass, and it became coal.
- At first the coal was soft, or bituminous.
- At some time in that distant past a great earthquake twisted and folded this Pennsylvania plain.
- The great heat and immense pressures, due to this disturbance, changed the soft coal into Anthracite
The How Coal Mines Work: "Mining and Preparation of Anthracite Coal" video below shows the anthracite mining process in the 1930s..
This Pennsylvania Anthracite Coal Mining video shows 1920s Pennsylvania coal miners at work.