"Memorandum presenting the development of a static pressure head for high speeds. These tests proved the practicability of static pressure heads at speeds up to 400 km/h (248.5 mph). It weighs 6.5 kg or 2.5 times as much as the old head. The position of the pressure head below the airplane was determined by bearing method at different speeds and for different lengths of suspension" (p. 1).

"Thin-walled shells with strong longitudinal and transverse stiffening (for example, stressed-skin fuselages and wings) may, under certain simplifying assumptions, be treated as static systems with finite redundancies. In this report the underlying basis for this method of treatment of the problem is presented and a computation procedure for stiffened cylindrical shells with curved sheet panels indicated. A detailed discussion of the force distribution due to applied concentrated forces is given, and the discussion illustrated by numerical examples which refer to an experimentally determined circular cylindrical shell" (p. 1).

"Factors are obtained from semiempirical equations for correcting engine-cylinder temperatures for variation in important engine and cooling conditions. The variation of engine temperatures with atmospheric temperature is treated in detail, and correction factors are obtained for various flight and test conditions, such as climb at constant indicated air speed, level flight, ground running, take-off, constant speed of cooling air, and constant mass flow of cooling air. Seven conventional air-cooled engine cylinders enclosed in jackets and cooled by a blower were tested to determine the effect of cooling-air temperature and carburetor-air temperature on cylinder temperatures" (p. 49).

Data complied regarding wells and other water resources, including water quality analysis, measurements, and other relevant information.

After completion of the required calibrations, the Dornier open-throat tunnel is now in operation. With an elliptic test section of 3 by 4 m (9.84 by 3.12 ft.), its length is 7 m (22.97 ft.), its maximum horsepower 800, and its maximum air speed 60 m/s (134.2 mph). As to local uniformity of velocity, static pressure as well as jet direction, and turbulence factor, this tunnel is on par with those of the good German and foreign research labs.

"Extensive experimental measurements have been made of the downwash angles and the wake characteristics behind airfoils with and without flaps and the data have been analyzed and correlated with the theory. A detailed study was made of the errors involved in applying lifting-line theory, such as the effects of a finite wing chord, the rolling-up of the trailing vortex sheet, and the wake. The downwash angles, as computed from the theoretical span load distribution by means of the Biot-Savart equation, were found to be in satisfactory agreement with the experimental results" (p. 179).

Flight tests were made to demonstrate the particularity of employing fixed tabs in conjunction with a suitably designed differential linkage to reduce the force required to operate ailerons. The tests showed the system to be practicable with tabs of the inset type. The relative ineffectiveness of attached tabs for changing the aileron floating angle rendered them unsuitable. Experience gained in the investigation has indicated that the use of the system is limited to maximum deflections of one aileron relative to the other of less than 30 degrees and that the differential linkage should always be designed on the basis of the highest probable floating angle.

Data complied regarding wells and other water resources, including water quality analysis, measurements, and other relevant information.

"An investigation was conducted to obtain fuel-consumption curves for a single-cylinder engine with a Wright 1820-G and Pratt & Whitney 1340-H cylinder at varying speeds, manifold pressures, and air-fuel ratios. The 1340- H cylinder was tested at speeds from 1,200 to 2,400 r.p.m. and at manifold pressures from 21 to 38 inches of mercury absolute. Less than extensive tests were made of the 1820-G cylinder. The results of the tests showed that the minimum brake fuel consumption was obtained when the engines were operating at high torques and at speeds from 60 to 70 percent of the rated speed" (p. 1).

"Distributed lateral motions have been calculated for a hypothetical small airplane with various modifications of fin area and dihedral setting. Special combinations of disturbing factors to simulate gusts are considered and the influence of lateral stability on the motions is discussed. Fin area and wing dihedral were found to be of primary importance in side gusts. It was found that the rolling action of the wing with as much as 5 degrees dihedral was distinctly unfavorable, especially when the weathercock stability was small. It is pointed out that the greatest susceptibility to lateral disturbances lies in the inherent damping and coupling moments developed by the wing" (p. 507).

Report presents the results of an investigation made in the NACA 7 by 10-foot wind tunnel of a large-chord wing model with a duct to house a simulated radiator suitable for a liquid-cooled engine. The duct was expanded to reduce the radiator losses, and the installation of the duct and radiator was made entirely within the wing to reduce form and interference drag. The tests were made using a two-dimensional-flow setup with a full-span duct and radiator. Section aerodynamic characteristics of the basic airfoil are given and also curves showing the characteristics of the various duct-radiator combinations.

Report issued by the U.S. Bureau of Mines on the pegmatite deposits found near Tinton, South Dakota. The properties, and geology of the deposits are presented. This report includes tables, and maps.

Describes different types of southern pines, how to plant stock, and maintaining the trees as they continue to grow.

An analysis of the cooling problems for a finned cylinder is made on the basis of the known fundamental principles of heat transfer from pipes. Experimental results that support the analysis are presented. The results of previous investigations on the problem are evaluated on the basis of the analysis and the results. An illustration of the application of these principles to a specific problem is included.

Data complied regarding wells and other water resources, including water quality analysis, measurements, and other relevant information.

Describes the characteristics of the red-headed pine sawfly, the damage it causes to pine trees, and methods of control.

"Tables of stiffness and carry-over factor are presented for members in which the cross section and axial load do not vary along the length of the member. These tables are of use in solving problems in the stability of structural members under axial load as well as in application of the Cross method of moment distribution when the effects of axial load in the members are considered. The interval between successive values of the argument is small enough to make interpolation unnecessary in engineering calculations" (p. 1).

The present investigation may be considered as preliminary to the study of automatic stabilizers. We have sought to determine first how an airplane of average characteristics reacts against the principal disturbances it may encounter. Without entering into the general study of automatic stabilizers, the present work suggests the idea of a stabilizer whose sensitive member would be a wind vane or pressure plate.

Explains the causes and describes methods for preventing red clover failure.