From Introduction: "This bulletin presents some of the methods and devices used in the oil fields of the United States for reducing the number of accidents at derricks.

From Introduction: "The drilling and blasting practices described in this bulletin are chiefly those in use at the time of these visits. Information, obtained by correspondence, on recent changes at certain mines is also included. The bulletin is confined to descriptions and comparisons of drilling and blasting methods at the six open-cut mines."

From Scope of Bulletin: "This paper is confined largely to a discussion of methods of mining potash salts in France and Germany, in view of the possible application of similar methods when mining of the deposits in the southwestern part if the United States is undertaken, but it also includes a brief history of the German and French potash industry, a discussion of the geology of the deposits, a short description of the refining of crude salts for export, and an estimate of the cost of production."

Report discussing petroleum refinery statistics for 1926.

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."

Report issued by the Bureau of Standards discussing the comparison of American, British, and German metal fit standards. The comparisons between national standards of the three countries are presented and described. This report includes tables, and illustrations.

Report discussing the technology for mining silica and the various uses of silica in industry and the arts.

The Dornier Mercury (Merkur) is an outgrowth of the Dornier Komet. It is designed as a passenger aircraft with the Alpine routes in mind. Its fuselage is made of steel for high stressed parts and duraluminum for all others. It can also be outfitted as a seaplane.

Scientific paper issued by the Bureau of Standards over studies conducted on radio fading. As stated in the abstract, "the series of measurements on fading were devoted to studies of fading effects during the sunset period, effects during the solar eclipse of January 24, the fading variations throughout a 24-hour day, and the effects of high transmitting power on fading" (p. 419). This paper includes tables, maps, illustrations, and photographs.

Technical paper issued by the Bureau of Mines over studies conducted on rotary kilns. As stated in the introduction, "the object of this study was to determine the factors that influence the rate of progress of crushed materials through a kiln" (p. 1). This paper includes tables, illustrations, and photographs.

Technical paper issued by the Bureau of Mines over mining of red iron ores in Birmingham, Alabama. As stated in the introduction, "the present paper deals more specifically with the development and handling of ore as affected by folds and faults in the ore bed, and considers changes that may be desirable or necessary in future mining practices" (p. 2). This paper includes illustrations, and photographs.

In November 1926, an exhibition flight of the Dornier giant flying boat was made for 3/4 of an hour. It was a larger version of the Dornier Wal, with a stepped hull, and wing stubs for lateral stability. It has a range of 1200 miles and is outfitted for baggage and 8 passengers.

The M. 39 was designed by Castoldi to compete in the Schneider Cup Race of 1926 (Norfolk, VA). It is a monoplane with engine mounted in the fuselage, resting on two wing and hull mounted floats.

The three engine Junkers commercial Airplane, type G 31 is a further development of the earlier G 24. It is an all metal low wing monoplane with a total engine output of 1100-1200 HP.

The RO VII is a monoplane with two 230 BMW engines mounted on top of the wing. It seats 4 passengers with room for a pilot and a mechanic in the cockpit. A description of the components, dimensions, performances, drawings, and photographs are provided.

Circular presenting a description of the Heinkel H.E.5 commercial seaplane. Its primary important characteristics are a short start, agreeable flying qualities, and long radius of action. Details of the design and flying characteristics are provided.

The Rocco is a has a monoplane wing surmounted by two engines. Its flat sided narrow beam hull is steadied when on the water by 2 outboard wing floats. Details of the design, hull accommodation, power plant, drawings, and photographs are provided. The report is incomplete.

A small commercial airplane, the Focke-Wulf G.L. 18 has two engines (75 HP. Junker). It is a monoplane and the engines are wing mounted. Details of the engines, power, wings, ailerons, fuselage, empennage, landing gear, characteristics, drawings, and photographs are provided.

The G 24 is a commercial airplane with three engines and a monoplane wing. It is known for its all metal construction and stabilizers.

In order to clear up the matter ( In the Spanish report it was stated that the reference surface for the calculation of the coefficients c(sub a) and c(sub w) was the area of all four wings, instead of a single wing), the model of a windwill airplane was tested in the Gottingen wind tunnel.