From Introduction: "The purpose of this report is twofold-to give a permanent printed record of all past data and to present them on the recently adopted basis of barrels instead of gallons."

From Scope of Bulletin: "This bulletin gives the results of a study of present conditions in Alaska placer mining, including the methods employed and the costs, and will be helpful to placer miners, engineers, and all others interested in the industry."

From Introduction: "This report describes the methods used and the results obtained in a series of experiments on the resistance that metal-mine airways offer to the flow of air."

From Introduction: "The Birmingham district holds large deposits of red hematite, coal, and flux extends from Springville on the northeast to below on the southwest. The work was begun in July, 1923, and ores from a number of points within the Birmingham district have since been studied. A method of magnetic concentration has been investigated which, it is believed, will successfully remove a large part of the gangue and incur only a small loss of iron.

From Preface: "The importance of fluorspar in the industrial development of this country, particularly in the open-hearth steel industry, has only begun to be realized fully, The World War showed that fluospar was an essential mineral and was not as abundant as has been supposed. Mr. Ladoo visited nearly all the important fluorspar mines and mills in the United States and obtained as much information as possible regarding foreign deposits, production and methods."