Report presenting charts for the calculation of the critical stress for local instability of columns with I-, Z-, channel-, and rectangular-tube sections. An experimental curve is included for use in taking into account the effect of stresses above the elastic range on 24S-T aluminum alloy elasticity.

Report issued by the U.S. Bureau of Mines on testing conducted on coking coal samples for carbon electrode use in aluminum production. The testing methods, and results are presented. This report includes tables.

Report presenting a comparison of the results of calculations of the critical flutter speeds of nine uniform rectangular wings without ailerons by two methods: one in which the effect of the wing flutter shape is introduced indirectly by choosing mean values for the wing parameters and one that introduces an additional degree of freedom in the wing-bending flutter mode.

Report presenting a chart for the values of the coefficient in the formula for the critical shear stress at which buckling may be expected to occur in an infinitely long flat plate with parallel edges. An approximate method for the evaluation of the critical shear stress when the elastic restraints on the two parallel edges are not equal is also presented.

"A simple interaction curve is presented for evaluating the conditions of combined shear and direct stress under which an infinitely long, flat plate with equal elastic restraints against rotation along the edges will become unstable. The theoretical work that led to the interaction curve is presented in the form of appendixes" (p. 1).

Report presenting a correlation of the gross-load coefficient and the forebody length-beam ratio for a limited number of present-day multiengine long-range flying boats for which the spray characteristics are known. Results indicate that the gross-load coefficient for comparable spray characteristics varies as the square of the forebody length-beam ratio.

Report presenting tests to determine the behavior of landplanes when they are forced to land on the water. The report is incomplete.

Report presenting a series of performance tests made with a CFR engine at constant inlet pressure and temperature and constant exhaust pressure. Special cylinder heads with different sizes and designs of inlet valve and port were used.

Report presenting tests of various types of riveted joint composed of 24S-T sheet and 1/8-inch A17S-T rivets in order to determine the effects of specimen type on shear strengths. The results indicated that there was only a slight variation in shear strength with considerable variation in the types of specimen.

Report issued by the U.S. Bureau of Mines on experiments conducted regarding the desulfurization of distillates from crude oil. Characteristics and desulfurization processes are presented. This report includes tables, and a chart.

"Experimental results of tests made at the Langley Memorial Aeronautical Laboratory are presented to show how heat-transfer coefficients can be increased by a method utilizing the high rate of heat transfer known to exist on any heat-transfer surface in the region adjacent to the edge on which the cooling or heating fluid impinges. The results show that, for the same pressure drop, the average surface heat-transfer.coefficient can be increased 50 to 100 percent when a cooling surface having a length of four inches in the direction of fluid flow is cut to form twenty fins with a length of 0.2 inch in the direction of fluid flow and the fins are sharpened and staggered in the air stream" (p. 1).

Report presenting an investigation to determine the departure of the static pressure measured at fuselage static-pressure vents from the static pressure of the ambient air. Several locations for fuselage static-pressure vents on an XB-24F and a Lockheed 12A airplane.

Report presenting a description of the development of thermal ice-prevention equipment by the application of a heated-air ice-prevention system to a Lockheed 12A airplane. Test data indicated that thermal ice-prevention equipment is practical and that the method of utilizing the exhaust gases as a source of heat is satisfactory.

Report presenting an iteration method employed to obtain the flow of a compressible fluid past a curved surface. For small Mach numbers and thin shapes, the results obtained by the iteration process agree with those obtained by the Poggi method.

Report issued by the U.S. Bureau of Mines on the oil production from water injection methods. As noted in the introduction, "it is the purpose of this report to present data such as volume of oil produced monthly, volume of water injected monthly, spacing of wells, number of injection wells and oil wells, and other such pertinent information" (p. 5). This report includes tables, graphs, maps, and illustrations.

Report presenting tests in the two-dimensional low-turbulence pressure tunnel to study the interference effects of various pusher-propeller shaft-housing combinations on a low-drag airfoil. Thirty different combinations were tested, variations being made in shaft size, shape, angle, and fillet.

Report presenting a method and apparatus for making quantitative tests of the spray characteristics of flying-boat-hull models. The method is applied to three related models of flying-boat hulls which differed in one major characteristic of shape: the overall dead rise.

Report presenting a study of a single-cylinder piston-ported two-stroke engine in order to investigate means of obtaining reliable operation under idling conditions. The fuel-consumption characteristics were also studied over the useful range of speeds and loads. Results regarding illuminating gas, vaporized gasoline, gasoline injection, injected safety fuel, and brake specific fuel consumption are provided.

Report discusses the results of testing on the dynamic stability characteristics of various hydrofoil systems for seaplanes, including a flat-hydrofoil tandem system, a 20 degree V-hydrofoil tandem system, a curved-hydrofoil tandem system, a flat-hydrofoil ladder system, a Guidoni S.V.A.-type hydrofoil on a streamline spindle, and several self-propelled models, including the Tietjens hydrofoil system. The instability and spray were compared for the different systems.

Principles of the cross method of moment distribution, which have previously been applied to the stability of structures composed of bars under axial load, are applied to the stability of structures composed of long plates under longitudinal load.

Report discussing the difficulty in pulling of high-speed dives, which is primarily due to the effect of compressibility on the lift of the wing. Some of the means described for providing increased longitudinal control include auxiliary flaps and a controllable stabilizer.

Report issued by the U.S. Bureau of Mines discussing the recent supply and demand of fuels. As stated by the author, "my purpose in this address is to review the changes in fuel supply and demand since 1937 and to give you my views on the outlook for the future" (p. 1). This report includes tables, and illustrations.

"This report summarizes the work that has been carried on in the experimental investigation of the problem of the general instability of stiffened metal cylinders subjected to combined bending and torsion at the C.I.T. This part of the investigation included tests on 26 sheet-covered specimens. An interaction curve for the case of combined bending and torsion is presented. The results of tests of 17 specimens subjected to pure torsion are also given" (p. 1).

Report presents tables of stiffness and carry-over factor for infinitely long flat plates subjected to a uniformly distributed longitudinal compressive load. The tables can be used to help solve problems in the stability of structures made out of plates under compression.