"This report presents the results of tests made on three sizes of roots type aircraft engine superchargers. The impeller contours and diameters of these machines were the same, but the length were 11, 8 1/4, and 4 inches, giving displacements of 0.509, 0.382, and 0.185 cubic foot per impeller revolution. The information obtained serves as a basis for the examination of the individual effects of impeller speed and displacement on performance and of the comparative performance when speed and displacement are altered simultaneously to meet definite service requirements" (p. 3).

The investigation presented in this report was conducted for the purpose of determining the distribution and magnitude of water pressures likely to be experienced on seaplane hulls in service. It consisted of the development and construction of apparatus for recording water pressures lasting one one-hundredth second or longer and of flight tests to determine the water pressures on a UO-1 seaplane float under various conditions of taxiing, taking off, and landing. The apparatus developed was found to operate with satisfactory accuracy and is suitable for flight tests on other seaplanes. The tests on the UO-1 showed that maximum pressures of about 6.5 pounds per square inch occur at the step for the full width of the float bottom. Proceeding forward from the step the maximum pressures decrease in magnitude uniformly toward the bow, and the region of highest pressures narrows toward the keel. Immediately abaft the step the maximum pressures are very small, but increase in magnitude toward the stern and there once reached a value of about 5 pounds per square inch. (author).

This is an all metal aircraft, including the wing coverings. Both the framework and the sheet-metal coverings are Alferium, made by Schneider Co. A description of the wing, fuselage, landing gear, engines, fuel tanks, characteristics, drawings, and photographs are provided.

I am now proposing a method for the preliminary approximate calculation of the thrust distribution and efficiency of air propellers under any operating conditions. Our task becomes the following, namely, to determine the speed relations and the forces developed on a section with a given direction and velocity of the air current, a problem which can be solved with the aid of the momentum theory.

Report examining the aerodynamic characteristics of three airfoil sections as determined in the variable density wind tunnel. Particular attention is given to the relation of the characteristics to the angle of attack and their use in airplane design.

It is proposed in this paper to identify some of the defects and failures in duralumin most frequently encountered by the aircraft industry with a view to indicate their importance. The defects and failures in duralumin may be classified into the following groups: 1) defects produced during manufacture; 2) defects produced during fabrication; 3) corrosion and erosion; and 4) fatigue failures. Only the first two will be covered in this report.

"The main object of these wings was to obtain a high lift without increasing the total drag, and the idea was conceived that, by using a deep high-lift section for the top wing and a medium section for the bottom wing, the mutual interference between the two would be such as to give greater efficiency of the combination as compared with two wings of equal section" (p. 1).

The H.D. 40 has a compound structure in which metal has been used at stress points. It is powered by one BMW IV 460 H.P. engine.

The investigation was limited chiefly to the region of high angles of attack since it is only in this region that any considerable change in the character of the flow can be expected from such artificial aids. The slot, through which compressed air was blown, was formed by two pieces of sheet steel connected by screws at intervals of about 5 cm. It was intended to regulate the width of the slot by means of these screws. Much more compressed air was required than was originally supposed, hence all the delivery pipes were much too small. This experiment, therefore, is to be regarded as only a preliminary one.

Describes several different pests which attack rice crops in the United States, including: stinkbugs, water weevils, borers, and several other minor pests; also describes the methods of controlling these pests.

This report contains descriptions of construction techniques at the Vickers plant including the building of the "wandering web," the spar flange, and the Vickers spars.

Describes the smut diseases that affect wheat and rye, and methods for their control.

Describes the characteristics of the striped blister beetle, the damage it causes to soybeans, and methods of control.

"This investigation was made for the purpose of determining the characteristics of five full-scale propellers in flight. The equipment consisted of five propellers in conjunction with a VE-7 airplane and a Wright E-2 engine. The propellers were of the same diameter and aspect ratio. Four of them differed uniformly in thickness and pitch and the fifth propeller was identical with one of the other four with exception of a change of the airfoil section" (p. 267).

The calculations in this paper afford an approximate solution of the static stability. A derivation of the formulas for moment coefficient of a wing, moment coefficient of elevator, and the total moment of the combined wing and elevator and the moment coefficient with reference to the center of gravity are provided.

"It is known that in a biplane the load is not distributed equally between the wings. The presence of one wing will affect the lift characteristics of the other wings. A designer must know the total load that each wing carries in order that he may design an adequate structure. The purpose here is to determine the distribution of loads between the wings of a biplane at various angles of decalage, when the gap/chord ratio is one, and there is no stagger" (p. 1).

The present report contains the results of a few experiments on three airfoils to which the rear portions, having chords respectively 1/4, 1/3, and 2/5 of the total chords, are hinged so as to form ailerons, especial attention being given to the shape of the slot between the aileron and the main portion of the aileron.

The Vega is a high wing monoplane suitable for commercial purposes. It can seat 6 passengers or 100 cubic feet of cargo. Various characteristics of the aircraft are described, including the wings, control surfaces, landing gear, and power plant.

The Mailwing is a single seat biplane designed primarily for mail and express delivery. It has a cargo capacity of 500 to 600 lbs. Details regarding the construction, engine, fuel tank, wings, tail, landing gear, propeller, control, characteristics, performance, drawings, and photographs are provided.

Report describing information that should be provided for miners when they are first being trained on-site, as well as an explanation about the education program offered by the Practical Mining School at Dawson, New Mexico.

Report on the need for regulations and inspections to counter preventable mine roof collapses and resulting injuries and fatalities.

This report presents methods to reduce the incidence of aviation accidents. Some of the methods discussed include enlistment and training of aviators, improvement of controls and control surfaces, and upgrading of power plants.

The structural details such as wings, fuselage, landing gear, and steering organs of German gliders are detailed in this report.

Describes farming systems in which dairy, beef, and sheep production are combined with the production of cotton and Johnson grass hay.