The problem before us is to determine the total stresses in an axially loaded column of any degree of restraint which is also subject to transverse bending both from a uniformly distributed load and from concentrated loads. The solution of this problem is of special importance in the design of aircraft which consist of slender columns" (p. 1).

The organization of a meteorological service for an air route involves the solution of two distinct problems: distribution and grouping of meteorological stations and communications. Experience gained in the establishment of two lines, Paris-Warsaw and Constantinople-Bucharest enables us to establish certain principles, which may be of interest to note here.

This report is broken up into two sections: one about the regulators for speed of wind tunnel drive motor and one about a vernier manometer with adjustable sensitivity.

"A device which does for the aircraft what change speed gears do for the automobile is the invention of Spencer Heath. It comprises a system of special blades and a mechanism for varying the pitch of the blades from zero to 360 degrees, while in flight or otherwise. By adjusting the pitch, either before starting or while the engine is running, to a less than normal angle, the engine is allowed to pick up speed and deliver its maximum power which is necessary in taking-off with a heavier load than the same airplane could otherwise normally carry" (p. 1).

At the request of the N.A.C.A. the "Universal Propeller" was operated and explained by the inventor, Mr. Spencer Heath, for the purpose of demonstrating the following features of design: 1) Elimination of continuously running gears, collars or bearings in the pitch control mechanism; 2) The use of engine power in place of manual labor in changing blade angle; 3) The absence of any structural limitation to the range of blade angles available and the possibility of limiting the blade travel between any two predetermined extreme positions; 4) Continuous indication on the instrument board of the blade position; 5) Automatic throttling of the engine while the propeller is passing through the position of neutral pitch.

This report presents the results of testing 32 sets of light metal pistons from 16 different aluminum and magnesium alloys, 2 sets of cast iron pistons, and one piston of pure electrolytic copper. The many-fold mutual relations between material properties, shape, thermic and dynamic processes in the engine were clarified by comprehensive technical, thermic, chemical, physical and metallographic investigations of pistons and piston materials.

Given here is a brief review of the fundamental principles of the propeller slip-stream theory and its further development through later researches, which demonstrate the connection between the propeller slip-stream theory and Frounde's so-called 'propeller blade theory.' The propeller slip-stream theory, especially in its improved form, now gives us the basis for determining the mutual influence of the parts of the blade, so that, in calculating the shape of the blade, we can get along with certain section characteristics, which have been determined once and for all. It is argued that new theories present the possibility of investigating the phenomena in the vicinity of the propeller, allowing us to calculate its action on the basis of fewer experimental values.

Report presenting information regarding the use of slots in an airplane wing to considerably increase the lift and make it possible to operate the wing at higher angles of attack.

Report presenting a description of considerations that go into the layout and building of an aircraft landing field or airstrip. Some of the elements considered include the shape and size of the plot, general arrangement, buildings present near the airstrip, runways, grass, roadways and railroad tracks, field markings, and some miscellaneous factors are provided.

The author discusses cost of operating commercial airplanes and endeavors to clear up prevalent misunderstandings. Curves of operating cost for varying duration, speed, reserve horsepower, etc. are developed.

This report presents the results of testing on a glider designed and built by the College Aviation Group. The design and construction were based on the following principles: 1) the glider will be made to descend as slowly as possible; 2) rigidity and resistance were arranged to meet the conditions of varied loads; 3) construction is as simple as possible; 4) and great ease in assembling and dismounting have been sought.

From Introduction: "The purpose of this bulletin is to point out the most efficient methods and equipment now in use in slate quarries, to describe methods of utilizing the quarried material to best advantage, and to outline means of reducing the proportion of waste, which is now excessive."

"A method is described for synchronizing the different instrument records taken during flight testing. This method has been in use for sometime at the Langley Memorial Aeronautical Laboratory and has proved very valuable in connection with the study of controllability and other complicated problems of flight" (p. 1).

This report is a description of a method of propelling airplanes by the reaction of jet propulsion. Air is compressed and mixed with fuel in a combustion chamber, where the mixture burns at constant pressure. The combustion products issue through a nozzle, and the reaction of that of the motor-driven air screw. The computations are outlined and the results given by tables and curves.

Ballistics is a science hundreds of years old and this report is an attempt to show how these older principles can be used in the newer science of aerodynamics.

"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).

In the following report, we will first draw some conclusions of purely theoretical interest, from the general equations of motion. At the end, we will consider the motion of an airplane, with the engine dead and with the assumption that the angle of attack remains constant. Thus we arrive at a simple result, which can be rendered practically utilizable for determining the trajectory of an airplane descending at a constant steering angle.

The future of aerial photography is examined with special reference to corporate uses.

"In several instances where control flaps are placed in the trailing edges of thick sections, it has appeared that a dead center (slackness or lack of control) exists about the neutral position. The condition was also experienced in the rudder action of the XB1A observation airplane. Examination of smoke pictures of the airflow around struts and airfoils indicates what may be the cause of the phenomenon" (p. 1).

Report issued by the Bureau of Mines discussing a manual written for individuals who use natural gas in the home. As stated in the introduction, "its purpose is to tell about the supply, production, and distribution of natural gas, so that the necessity for preventing waste will be better understood" (p. 1). This report includes a map, illustrations, and photographs.

Goldbeater's skin, which is the prepared outside membrane of the large intestine of an ox, is examined as a balloon fabric and details of how goldbeater's skin is prepared for use are provided. The construction techniques employed by Germany, France, and England are all discussed.

From Introduction: "Part I of this paper discusses briefly some of the features of oil and gas accumulation and describes certain oil-field rocks and minerals. Part II deals with the kinds of tools that should be used and the information necessary for selecting proper tools. Part III discusses the accurate testing of strata for oil or gas and states principles based on conditions that have frequently existed in well drilling."

A design for a wind vane is presented and various applications are discussed. The equations that can be used to calculate effects on the aircraft using the vane and control assistance that can be provided using the wind vane are provided.

In order to determine an approximate formula giving the weight of a dead load as a function of the volume (V) of the envelope and of the maximum velocity (v), we will take the relative weight of the various parts of the airship (P(sub v), M, V, A, T(sup 34)), adopting a mean value of the coefficients determined. This formula may be adopted both for semi-rigid airships with suspended nacelle and non-rigid envelope, with or without internal suspensions. It may also be adapted to airships with rigid longitudinal beam, with power units on external supports or in nacelles, and with non-rigid envelopes, with or without internal bracing cables.