The first group of a large series of contemplated experiments on the effect of roughness was intended to show the effect of great roughness on airfoils of various sizes and attitudes.

In this work I have attempted to find a basis for the design of fuel cams, which will serve equally for large and small engines, both high-speed and low-speed.

Lautal is a refinable aluminum alloy which, unlike duralumin, contains no magnesium. According to the statements of the Lauta Works, lautal contains: aluminum, 94%; copper, 4%; silicon, 2%. The use of lautal as a construction material is discussed in relation to specific weight, production methods, and riveting tests.

"It is obviously interesting to know the names of those who were the first contributors to aeronautical science. Therefore, without claiming to give a complete history, I present in this article a summary list of names in chronological order relating to the history of experiments on the resistance of the air and its application to aeronautics" (p. 1).

Report presenting an attempt to determine mathematically the buckling-strength curves of various centrally loaded light-metal tubes which exhibit conspicuous differences of behavior under compressive loads. For this purpose, Von Karman's method is used after adapting it to special conditions.

During a flight with a Van Berkel W. B. seaplane it was observed that the wing could perform violent oscillations. A theoretical and experimental investigation led to the conclusion, that in some cases an unstable oscillation of the wing-aileron system under the influence of the elastic and aerodynamic forces is possible without further external causes.

This report tries to solve the problem of supplying the engine cylinders with a mixture of fuel and air in the right ratio to obtain the greatest power from the engine with the least consumption of fuel.

Different methods for increasing the efficiency of diesel engines are presented and some new designs are given.

Memorandum presenting a general overview of aircraft constructed from metal and fuselages constructed from strip metal.

The report considers the effect on engines of the varying types of fuels now in use. Different types of fuels are examined and the influence of physical characteristics are considered.

Since the war there has been a considerable advance in knowledge on the subject of the airfoil and its behavior. The theory is now sufficiently advanced to make it possible to predict and to calculate certain results which previously could only be attained by direct experiment. The vortex theory receives special attention.

Experimental data, such as the results of tank tests of models, render it possible to predict, at least in principle, as to how a hull or float of a given shape will comport itself. We will see further along, however, how uncertain these methods are and how they leave room for empiricism, which will reign for a long time yet in seaplane research bureaus.

Report presenting some topics related to safety in flight and the importance of having accurate statistics and information regarding aircraft problems and accidents. Some of the topics provided included perverted statistics, the British accident record, unregulated air traffic in America, and air mail in bad weather.

Report discussing tires, steel springs, hydraulic shock absorbers, and axle travel are all examined in relation to absorbing landing shocks.

The difference between aircraft for commercial and wartime uses is delineated, but the interchangability between the two is also discussed. Airships in both roles are also presented.

The development of the parachute is presented as well as the future possibilities. The primary topics covered include allowing for wind in design, the parachutes used at balloon exhibitions, parachute use in the war, the delayed-opening type of parachute, and the use of parachutes on commercial airplanes.

This report presents a study of an instrument that can warn the pilot of the turning of his airplane. This instrument must satisfy three conditions: 1) It must give useful indication immediately from take-off; 2) The indications must be instantaneous and require no exertion by the pilot; 3) The indicator must be sensitive only to changes of orientation in the horizontal plane. Different solutions are presented such as a gyroscope driven by the suction of a Venturi tube.

"A transverse test was made of the wood sample using a 5,000 pound Olsen testing machine, the deflection under load being measured by means of a Wissler dial. The results of the transverse test are given and the stress-strain curve is attached" (p. 1).

Different aspects of aircraft regulation are discussed such as: protecting the public; the restriction of flights over crowds; regulations of wing-walkers.

This report presents examples of different methods of comparing aircraft mathematically. In the example given a biplane and monoplane are compared as to what speed one type of airplane is better at than another.

"The Coutinho-Sacadura course corrector is an instrument with which, knowing the angles of drift of two different courses, we may determine by simple readings: a) direction and velocity of wind; b) correction to be made in course followed by compass, in order to fly in a given direction; c) ground-speed of aircraft, the resultant of its air speed and the velocity of the wind" (p. 1).

Different illumination systems for landing fields are presented which include fixed beacons, signal guns, and light patterns such as T's and crosses. Some of the advantages and disadvantages for each of the lighting patterns are provided.

The wing strain meter enables a pilot to know the strain on lifting surfaces and to warn him of the safe limits which may not be exceeded. In wing strain the most important factors are the force of gravity and the force of lift which gives the measure of the sustaining force, and their components which are perpendicular to the lifting surfaces. This reports methods for using the wing strain meter.

This report is a comprehensive study of birds and how their shapes have been molded by the resistance of the air. 500 species of birds were studied and nearly 30,000 ratios calculated. The author makes a distinction between flapping and soaring flight.