Outline of Problem: "This paper covers a survey of 19 ores collected from seven of the more important iron-ore districts of the United States and is a contribution by the ore-dressing section of the United States Bureau of Mines to general research program on iron and steel being conducted by the Bureau."

From abstract: Detailed knowledge of the geology of the pre-Cambrian rocks of the Lake Superior region has been greatly augmented since the publication of Monograph 52 by the United States Geological Survey in 1911. The authors have attempted in the present report to assemble as much of this new information as possible, and to give the reader a birdseye view of the geology as seen in the light of all studies made there up to the present time. Detailed descriptions are not presented, and the emphasis is placed upon the major problems of correlation. A revised map of the region, with cross sections, accompanies the report, bringing up to date a knowledge of the areal geology of the region, which otherwise could be gained only by consulting some 150 maps contained in almost as many separate local reports, many of which are unpublished.

Description of geology in Minnesota and explanations of glacial drift within the state an immediate surroundings (Wisconsin, Iowa, North Dakota and South Dakota) with sections detailing the movement of each glacier and relevant geological notes. Index starts on page 147.

Report issued by the U.S. Bureau of Mines discussing the mine stations and safety cars used to reach miners in distress. As stated in the report, "the purpose, equipment, personnel, and construction of its safety cars" is presented. This report includes an illustration, and a map.