The construction of the Magnan glider, M-2, is presented which is designed to fly in so-called horizontal winds. Details of the wings, fuselage, tail surfaces, controls, landing gear, characteristics, operation, photographs, and drawings are provided.

The problems as to how an airship can best be stabilized and steered and to what stresses it is subjected in the air, are so important as to determine in large measure the future development of airships much more than formerly when velocities of 30-35 meters (98-115 feet) per second were not known and the effects of the air flow were not so great.

The first part of this report shows the differences between commercial and war airships and then goes on to show how some of the problems were solved. Their thorough investigations of these problems finally enabled the Schutte-Lanz Company to construct bulkhead diagrams for determining the buoyancy of airships, by means of which the size of each cell was established. These diagrams were derived from bulkhead diagrams employed in ship designing and are used in a similar manner.

The author describes experiments in designing nonrigid airships. A nonrigid airship of 32,000 cubic meters, the PL 27 withstood all stresses with 20 kg/m(exp 2) hull pressure during its life of two years. The moment of resistance is known, as also the stresses in the envelope for the given hull pressure. The mean internal pressure necessary to give the airship the requisite rigidity and to prevent buckling was also investigated.

Report presenting the development in air transport that has taken place since civil aviation between England and Europe started at the end of August 1919. The primary subjects explored include the character of loads on aircraft, routes operated, results in passengers carried and efficiency of the service, costs of the service, question of subsidies, and probable future developments.

Memorandum presenting an overview of ultra-light alloys and their potential use on an aircraft. A definition of ultra-light alloys, some of the present possibilities of ultra-light alloys, and some of the principles governing the use of the alloys in aircraft are provided.

"These notes are intended to furnish practical and general data on the effect of altitude on engine power. The effective horsepower of an engine is a function of the mean pressure of the fluid acting on the pistons, of the R.P.M. of the engine and of the mechanical efficiency" (p. 1).

The present report treats the subject of testing small models in a wind tunnel and of the methods employed for rendering the results constant, accurate and comparable with one another. Detailed experimental results are given.

Memorandum describing a device, constructed according to the system of Gati, with which it is possible to measure the sound of an engine and test the effect of a silencer.

The knowledge gained from previous experiments and reports was utilized for the construction of a dynamometer hub for 200 mkg (134.4 ft.-lb.) and 1200 kg (2646 lb.) thrust suited for a Liberty "12" engine. A reversing device is also described.

Methodical experiments with the series of airfoil sections of the same relative thickness and of variable relative cambers can be utilized for determining the effect of the camber on the aerodynamic properties of airfoil sections.

In studying the application of his system of varying the camber of airfoil sections, Mr. Lachassagne has just obtained a series of airfoil sections whose polar envelope presents truly remarkable aerodynamic properties.

Differential and integral curves are presented and well as numerous calculations relating to hulls. Some of the calculations include those relating to hulls, those relating to the invariability of the shape of the hulls, and those relating to the suspension of the hull.

This report seeks to determine what constitutes airplane performance and what line should be followed in seeking to break records if the designer is given a free hand. Some of the considerations for designers include the ratio of engine power to wing area, minor refinements, low wing loading, and duration.

This report describes the apparatus used to take air-flow photographs. The photographs show chiefly the spiral course of the lines of flow near the tip of the wing. They constitute therefore a visual presentation of the phenomena covered by airfoil theory.

"The question of behavior of a streamlined body with round or square cross-sections is of importance in determining the shape to give an airplane fuselage. It is our task here to show how the lift and drag are affected, with the object placed obliquely to the air stream" (p. 1).

The theory (wing experiments in an artificial air stream are subject to error, due to the fact that the wing is not situated in an unlimited body of air) by means of which the given drag correction was obtained, was based on various assumptions (e.g., elliptical distribution of lift) which do not always hold true. For this reason it was desirable to test the equation for the additional drag in regard to its reliability and range of application.

The theory, structure and working of a vector slide rule is presented in this report. This instrument is used for determining a vector in magnitude and position when given its components and its moment about a point in their plane.

The use of exit cones and different blade configurations to reduce the motive power required in wind tunnels is discussed in this report.

This report provides a description of the wind tunnel housing and motors at the Belgian Service Technique de L'Aeronautique.

The present article is a brief report on the development and testing of the Messerschmidt glider that set a duration record of 21 minutes. Its most conspicuous characteristic was the placing of the steering gear entirely inside the fuselage and wings.

Experiments were made on the resistance of four airplane wheels of different sizes and coverings and two Lamblin radiators. The results show the important influence of the wheel coverings. The closing of a shutter, which was fitted to one of the radiators, considerably lessened the resistance.

The improvement of airplanes and increased safety of air traffic can be sought in various ways. In the experiments described below, the aim was to find some simple and inexpensive method of modifying present-day airplanes, so as to improve and simplify the process of landing.

"The purpose of this memorandum is to present in a concise form a description, with drawings, of the most practical light airplanes participating in the meet at Lympne, England, in October, 1923. Features, which are particularly suitable for this type of aircraft, are described and a special reference is made to achievements which indicate progress and possibilities both from a commercial and a military point of view" (p. 1).