Report issued by the Bureau of Mines over investigations conducted on lignite. Preparation methods and uses of lignite are discussed. This report includes tables, maps, illustrations, and photographs.

Report issued by the Bureau of Mines over investigations conducted on lignite. Preparation methods and uses of lignite are discussed. This report includes tables, maps, illustrations, and photographs.

From General Statement Purpose of the Report: "The present investigation was undertaken for the purpose of supplying some of the material so badly needed in the valuation and more efficient operation of oil properties. Because of the lack of time for further studies, the amount of data already accumulated and the policy of the Bureau of Mines of publishing as soon as possible any information that may be of use to an industry, the bulletin is issued now."

From Introduction: "Technical Paper 66 deals with the mud-laden fluid process in general and No. 68 with its application in Oklahoma. Rather than reprint these publications, it has been considered advisable to replace them with the present report, which includes the results of more recent investigations. The methods of using mud-laden fluid are an outgrowth of the rotary drilling system, which was developed in Texas and later employed in Louisiana and California."

Report issued by the Bureau of Mines over western lignite. The economic use of these lignite deposits is discussed. This report includes tables, illustrations, and photographs.