Report presenting a description of the Lioré-Olivier LeO 194 seaplane and a particular series of flights made over several months. Its fuselage is made entirely of wood. It has 6 gasoline tanks each with a capacity of 255 liters. It is a single engine biplane with wings mounted above the body of the seaplane.

This report presents a thermodynamic basis for rating heat engines. The production of work by a heat engine rests on the operation of supplying heat, under favorable conditions, to a working fluid and then taking it away.

Circular presenting a description of the Westland IV, which is a high-wing monoplane with strut bracing, two outboard engines, a fairly large fuselage that provides comfortable cabin accommodation, and wide-track landing gear. Details of the design, flight characteristics, blueprints, and photographs are provided.

Circular presenting a description of the Blackburn Bluebird Mark IV, which is an all-metal airplane. Details are provided regarding constructional features, the cockpit, the gasoline system, and the flight characteristics.

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.

"The behavior of a liquid or gaseous medium, in which a solid body can move freely under the action of a force of constant magnitude and direction, is yet little known. Only in connection with a few special problems, which belong in this field, have experiments been tried and these chiefly concern technically important cases. The behavior of the simplest shaped bodies has as yet been scarcely investigated at all" (p. 1).

"This article resulted from the need of showing, in a simple way, how the aerodynamic properties of airfoils are affected by the shape of their profiles. No general solution of this problem could be found, since the profile shapes cannot ordinarily be expressed by simple mathematical formulas. This advantage is possessed only by the Joukowsky profiles and this discussion of the problem is therefore limited to them" (p. 1).

The author's first experiments with a glider on flight characteristics demonstrated that an accurate flight-path measurement would enable determination of the polar diagram from a gliding flight. Since then he has endeavored to obtain accurate flight measurements by means of kinetograph (motion-picture camera). Different methods of accomplishing this are presented.

Report discusses the results of testing on a B.M.W. engine in an altitude chamber where temperature and pressure can be controlled to simulate flight at various altitudes. Results for various engine speeds, altitudes, and propeller speeds are provided.

Report presenting a description of the Pander light biplane, including a description of the construction and flying characteristics are provided.

A traditional biplane design allows this craft to function with the speed and maneuverability necessary to perform as a pursuit aircraft while also being able to land on water. It featured retractable landing gear for water landings. It was powered with a 450 HP. Lorraine-Dietrich engine.

Report issued by the U.S. Bureau of Mines on the possibilities of increasing fuel production from crude oil. Methods of recovering oil that is lost by remaining uncondensed are presented. This report includes tables, graphs, and illustrations.

From page 1: The purpose of this circular is to show the degree of dependence of the United States upon foreign sources for the manganese required by its industries.

Report on the comparative gravities of oil extracted from different regions of the United States.

The following report endeavors to show that aeromechanical experimentation has become an important aid to theory. Experiments can be tried with separate parts of airplanes or with models of whole airplanes, with propellers, and with anything else that comes into contact with moving air.

Engine conditions such as pressure characteristics, temperatures, and mechanical fatigue enable the employment of a criterion of general fatigue which simultaneously takes account of both mechanical and thermal conditions, for the sake of comparing any projected engine with engines of the same type already in use.

The present work investigates, on the basis of Prandtl's wing theory, the form of the lift distribution when the ailerons are deflected in opposite directions. An ideal fluid and a wing with a rectangular form are assumed. The moments must not cause any rotation of the wing or any deviation from the rectilinear motion.

Report discussing a demonstration was given within the last few days at the British Museum by Mr. J. W. Gordon, author of "Generalized Linear Perspective" (Constable and Co.), a work describing a newly-worked-out system by which photographs can be made available for the purpose of exactly recording the dimensions of the objects photographed even when the objects themselves are presented foreshortened in the photograph.

A history of English metal spar construction is presented in this paper. The way in which different spar designs or spar materials influence the aircraft wing loading and aerodynamics is described.

"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).

A formula for calculating the safety of airplanes is given and the stresses on airplane components are calculated. Some questions regarding the information obtained from the formula and its application to safe airplane design for pilots are provided.

The object of this work has been to construct an apparatus for obtaining oscillogram of voltages and currents which are variable with respect to time and of the frequency which is constantly met in radio.

The causes of the destruction of the Dixmude are discussed and some conclusions are drawn. The author believes a gasoline fire instead of a lightning strike was probably responsible, but the public believes otherwise.

The author recounts his experiments with helicopters. The object of his investigations was to remain stationary in the air for five minutes and to make a closed flight at low altitude. Some of the topics discussed include stabilization, horizontal flight, and directional control.