Circular describing the Dewoitine D.500 pursuit airplane, which is an all-metal cantilever low-wing monoplane. Details of the fuselage, cockpit, control surfaces, weapons, landing gear, fuel tanks, wing, engine, characteristics, performances, drawings, and photographs are provided.

Circular describing the De Havilland Moth Three, which is a high-wing commercial monoplane with a steeply sloping windshield, strut-bracing of the wing, and relatively orthodox landing gear. Details of the construction, design, characteristics, performance, drawings, and photographs are provided.

Circular presenting a description of the I.A.R. pursuit airplane. Details of the design, ailerons, fuselage, fuel tanks, landing gear, and flying qualities are provided.

Circular describing the D.H. 83 "Fox Moth", which is a three-passenger light cabin biplane that is considered a commercial airplane despite taking many of its components from the company's existing two-seat touring and training light airplanes. A description of these components, design, flight characteristics, performance, drawings, and photographs are provided.

Circular describing the Avro 631 training airplane, which is a British two-seat light biplane that is meant to be affordable and small. Details regarding the wings, fuselage, tail unit, landing gear, power plant, accommodation, characteristics, performance, drawings, and photographs are provided.

Circular presenting a description of the Short Scylla, which is a 39-passenger landplane with four Bristol Jupiter XF BM engines. A description of the characteristics, blueprints, and photographs of the aircraft are provided.

Circular presenting a description of the Armstrong Whitworth monoplane, which is an all-metal, high-wing monoplane with landing gear that retracts into the wing-mounted engine nacelles. Details of the wings, wing spars, fuselage, controls, engines, speeds, drawings, and photographs are provided.

Circular describing the Mauboussin M 11 touring airplane, which is a two-place high-wing monoplane that is an enlargement of the M 10. Details of the wing, ailerons, fuselage, cockpit, fuel tanks, landing gear, tail, characteristics, performances, drawings, and photographs are provided.

Circular presenting an overview of the Westland Wallace, which is a general purpose aircraft used by the British Royal Air Force. A description of the design, flight characteristics, blueprints, and photographs are provided.

Circular describing the Vickers-Supermarine Scapa, which is a military flying boat which was designed to be used for observation, bombing, torpedo transport, and training and navigational instruction. Details of the aerodynamic design, structural features, engine installation, characteristics, drawings, and photographs are provided.

Circular presenting a description of the first British airplane with a retractable landing gear, which is a small and aerodynamically clean monoplane. A description of the design and flight characteristics is provided.

Circular describing the Avro 642, which is a mixed construction high-wing cantilever monoplane. Details of the engines, controls, interior, wings, cockpit, ailerons, landing gear, characteristics, performance, drawings, and photographs are provided.

Circular describing the Stieger ST. 4, which is a twin-engine low-wing monoplane of the full cantilever type. Details regarding the wing, fuselage, power plant, landing gear, characteristics, drawings, and photographs are provided.

Report issued by the U.S. Bureau of Mines on the properties of fluids produced from combination wells. The characteristics of test results of these fluids are described and presented. This report includes tables, graphs, illustrations, and photographs.

Report issued by the Bureau of Mines over engineering studies conducted on Oklahoma oil fields. The results of the studies are presented and discussed. This report includes tables, illustrations, and photographs.

Report issued by the U.S. Bureau of Mines on the fifth annual national safety competition. The states represented in the competition are listed. Accident-frequency rates are presented as well. This report includes tables.

Report issued by the U.S. Bureau of Mines on the coal mine related deaths during the month of April, 1931. The number of fatalities and the causes are presented. This report includes tables and graphs.

Report issued by the U.S. Bureau of Mines on two samples of crude oil collected from the Greasewood Flat area of northwestern Colorado. These samples were analyzed for many characteristics, and an approximate summary of those characteristics are presented. The report contains two tables of data.

Report issued by the U.S. Bureau of Mines on the specifications and development of methods used in plain-carbon steel production. Proposed methods and experiment results are presented. This report includes tables, graphs, and photographs.

In horology the friction between solids is of the greatest importance; one limited, however, to the application of the laws of Coulomb which, do not at all correspond with reality. This report presents a review of the subject and some general conclusions. The choice of lubricant is discussed as well as the pressure between frictional surfaces. The gears in a watch are used extensively as examples.

The crew of the "Fafnir" was given an excellent opportunity for collecting first-hand data as to the usefulness of gliders in the Alps. It is necessary to recount the remarkable glider achievements ahead of the Rhon Soaring Contest, in order to understand the tension and expectation with which the Rhon contest was anticipated. A description of some of the aircraft present at the event is provided.

This report presents a new theory which makes it possible to interpret the resistance and the trimming moment for any loading of a planing aircraft when these values are given for one load. This application of the new theory forms the basis of the present paper. Derivations of various conversion formulas are given as well as numerous examples.

"Many reports on various control systems are available, but the results cannot be generally applied since the effect of particular changes of surface-form and mounting are subject to variations depending upon airfoil section and influences of airplane layout. This report presents a simple analysis of several control systems in more general use. Elevators, ailerons, and rudders are all discussed" (p. 1).

"Exhaustive torsional-vibration investigations are required to determine the reliability of aircraft engines. A general outline of the methods used for such investigations and of the theoretical and mechanical means now available for this purpose is given, illustrated by example. True vibration diagrams are usually obtained from vibration measurements on the completed engine. Two devices for this purpose and supplementing each other, the D.V.L. torsiograph and the D.V.L. torsion recorder, are described in this report" (p. 1).