The tests at the Gottingen laboratory included: friction tests on a surface treated with emaillite, verification tests on the M.V.A. 356 wing, and comparative tests of wing no. 36 at the Eiffel laboratory. The examination of all these experiments leads to the belief that, at large incidences, the speeds registered by the suction manometer of the testing chamber of the Eiffel laboratory wind tunnel are, owing to pressure drop, greater than the actual speeds. Therefore, the values of k(sub x) and k(sub y) measured at the Eiffel laboratory at large incidences are too low.

"On April 15, 1920, the under Secretary of State for Aeronautics and Aerial Transport decided to adopt as Standard Atmosphere for official airplane tests in France, the atmosphere defined by the following law, known as the Law of the S.T.You.(Technical Section of Aeronautics): From 0 to 11,000 m. - 0=15-0.0065 Z and above 11,000 m. - 0= -56.5 degrees being the temperature in centigrade degrees at altitude Z expressed in meters. For altitude 0 the pressure is 760 mm of mercury. In the magazine "L'Aeronautique" Mr. A. Toussaint has already written at length on the first studies which led to the elaboration of this law. Since that time the results obtained have been confirmed by fuller and more abundant data which have justified the official adoption of the Law of the S.T.Ae" (p. 1).

This report examines the idea of coupling numerous engines together to turn a single propeller, which the author feels would free aircraft design from the problems of multi-engine and propeller design.

Though dissimilar, these two subjects have been united because they have some points in common. The computation of the movement of an airplane can only be correctly established if we are in a position to know exactly the thrust and resisting torque of the propeller for the various values of slip, which may vary greatly according to circumstance. The first part of the work concerns propellers and introduces as a fundamental variable, the true slip (delta) with respect to the effective pitch, which is the advance per revolution of the propeller corresponding to no thrust. The second part deals with characteristic curves of an airplane.

Report presenting tariffs that are written for all aircraft manufacturing companies to follow regarding aircraft orders.

The abolition of military qualifications gives free scope to new technical possibilities in the development of transport airplanes. This report notes the various considerations that must be made when designing aircraft to meet the needs of commercial passengers. Comfort and safety must be emphasized.

Report presenting a description of a meeting of the German Scientific Association for Aeronautics. The topics that were discussed are described.

This report presents a series of tests conducted to verify the formula for thrust P = q(exp 2) D(exp 2) V(exp 2), where P represents thrust, V the velocity of the airstream, D the diameter of the propeller, and q the lifting quality of a comparative propeller which is called the conjugate propeller.

Report presenting a description of the transition stage of airplanes and how it will change with new developments in aircraft design. The details of the debate between centralized or decentralized installation are also provided, including some of the pros and cons of each.

Here, the laws governing the flow of a compressible fluid through an opening in a thin wall are applied to the resistance of the air at high speeds, especially as applied to the automatic rotation of projectiles. The instability which we observe in projectiles shot into the air without being given a moment of rotation about their axis of symmetry, or without stabilizing planes, is a phenomenon of automatic rotation. It is noted that we can prevent this phenomenon of automatic rotation by bringing the center of gravity sufficiently near one end, or by fitting the projectile with stabilizing planes or a tail.

The characteristics of the airplanes built for the Gordon Bennett Airplane Cup race that took place on September 28, 1920 are described. The airplanes are discussed from a aerodynamical point of view, with a number of new details concerning the French machines. Also discussed is the regulation of future races. The author argues that there should be no limitations on the power of the aircraft engines. He reasons that in the present state of things, liberty with regard to engine power does not lead to a search for the most powerful engine, but for one which is reliable and light, thus leading to progress.

Report presenting an exploration of the application of model test results to full size construction, which assumes that either the resistance varies as the square of the speed within, the range of speeds in question or that the mechanical similarity law is fulfilled by the model test. The latter requires that the relation of airflow to the model be exactly like that for the large machine.

Descriptions are given of two captured helicopters, one driven by electric power, the other by a gasoline engine. An account is given of flight tests of the gasoline powered vehicle. After 15 successful flight tests, the gasoline powered vehicle crashed due to the insufficient thrust. Also discussed here are the applications of helicopters for military observations, for meteorological work, and for carrying radio antennas.

Technical paper issued by the Bureau of Mines over studies conducted on fire resistance on building columns. As stated in the introduction, "the purpose of this investigation is to ascertain (1) the ultimate resistance against fire, of protected and unprotected columns as used in the interior of buildings; (2) their resistance against impact and sudden cooling from hose streams when in a highly heated condition" (p. 12). This paper includes tables, illustrations.