Analyses of Coals in the United States with Descriptions of Mine and Field Samples Collected between July 1, 1904 and June 30, 1910 Part 2. Descriptions of Samples (open access)

Analyses of Coals in the United States with Descriptions of Mine and Field Samples Collected between July 1, 1904 and June 30, 1910 Part 2. Descriptions of Samples

From Introduction: "This volume contains the descriptions of the samples whose analyses are published in the preceding volume, Part I of this bulletin. The descriptions have been compiled from the notebooks of the persons who collected the samples, have been condensed from accounts given in published reports of the United States Geological Survey, or have furnished by the collection themselves. Inasmuch as the descriptions represent the work of many persons during a period of six years, and inasmuch as they were recorded under widely differing conditions, they necessarily vary in fullness detail."
Date: 1913
Creator: Lord, N. W.
System: The UNT Digital Library
Treatment of the Tungsten Ores of Boulder County, Colo. (open access)

Treatment of the Tungsten Ores of Boulder County, Colo.

Report discussing the the development of milling practice in Boulder County, the ore-dressing methods in use, and the local manufacture of ferrotungsten and tungstic oxide. Figures giving the production of tungsten concentrates in the Boulder district, in the United States, and in the world; data on the buying of tungsten ores; costs of production; and the normal tungsten requirements in this country are presented.
Date: October 1921
Creator: Bonardi, J. P. & Williams, J. C.
System: The UNT Digital Library