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- Directions for Sampling Coal for Shipment or Delivery
- Technical paper issued by the Bureau of Mines with instructions for coal sampling for shipment. As stated in the introduction, "this paper deals with the sampling of coal after it has been mined" (p. 5). This paper includes illustrations.
- Natural Ventilation of Michigan Copper Mines
- Technical paper issued by the Bureau of Mines over the ventilation of copper mines in Michigan. Natural ventilation of the mines and mining conditions are discussed. This report includes tables, maps, and illustrations.