Report presenting drag measurements made on a 10-percent-thick wing and 8-percent-thick tail and a 8-percent-thick wing, 6-percent-thick tail version of the X-1 airplane at a variety of Mach numbers. The drag of the thicker wing was found to be much higher than that of the thinner wing. The fuselage was found to cause interference with the wing of both models, making the separation of wing and fuselage drag difficult to determine.

Report presenting a general analysis that allows the rolling motions of an aircraft using a displacement-response, flicker-type automatic pilot to be determined. The system is not ideal for many stabilization problems due to inherent residual oscillations, but it offers a simple and economical solution in situations in which steady state oscillations are not a problem. Results regarding some general remarks, transient and steady states, stabilization boundaries, amplitude equations, and period equations are provided.

Report issued by the Bureau of Mines on the development of efficient mining methods for producing oil shale. Characteristics of the oil shale deposits of the Green River are presented. The results of core drilling and sampling in this area are also listed. This report includes tables, illustrations, maps, and photographs.

"In the first part, the boundary conditions for an open wind tunnel (incompressible flow) are examined with special reference to the effects of the closed entrance and exit sections. In the second part, solutions are derived for four types of two-dimensional open tunnels, including one in which the pressures on the two free surfaces are not equal. In the third part, a general method is given for calculating the boundary effect in an open circular wind tunnel of finite jet length" (p. 509).

Introduction: Part 2 of the Systematic Report continues and concludes the study of the Mollusca from the Miocene and lower Pliocene of Virginia and North Carolina. One hundred and nineteen species, only a fraction of the known fauna, are reviewed and 66 additional species are described and figured. (See faunal chart, pp. 180-183.) The report upon the gastropods suffers from the same shortcomings obvious in the work on the pelecypods. Most of the material is from old collections made before the importance of the exact placing of the fossil locality both areally and vertically was recognized. Many of the citations of outcrops are vague and the sections generalized. Detailed field studies, particularly on the zoning of the Yorktown formation in southern Virginia and northern North Carolina, were begun later by Wendell P. Mansfield, but he died in the summer of 1939 before the completion of the work.

From Introduction: "The purpose of this investigation was to determine whether the coal from beds mined in the Schwager and Lota mines will produce metallurgical coke suitable for use in the blast furnaces at the proposed steel plant at Conception, and whether the quality of the lower-rank coals from other areas in Chile, especially those in Magallanes, where the large coal reserves of Chile appear to exist; can be improved by processing."

Note presenting an analysis based on simple geometry of the effect of thrust-axis inclination on propeller disk loading. Calculations are in excellent agreement with available flight measurements, so that the analysis is indicated to be adequate for predicting the primary effects of inclination. Because of the possible large effects of wing and fuselage interference, flow angles at the propeller should be determined by survey for most accurate results.

Report presenting pressure distributions over a prolate spheroid of fineness ratio 6 and over a combination of this body with an NACA 65-010 wing section for a range of Mach numbers. Results regarding wall and sting interference, nature of flow over a model in the transonic region, development of supersonic flow from subsonic flow, and a comparison of experimental and theoretical flow at subsonic stream Mach numbers are provided.

Report issued by the Bureau of Mines on the Coso mercury deposits of Inyo County, and development of the bucket drill for obtaining samples. Descriptions of the physical features of the deposits are listed. This report includes tables, maps, photographs, and illustrations.

The theory of high energy nuclear stars depends on a theory of nuclear transparency and on a theory of nuclear evaporation. The transparency can be computed on the basis of a model proposed by R. Serber as soon as the interactions between the nucleons and the incident particle are known. The evaporation can be computed on the basis of the statistical model of the nucleus as soon as the nuclear entropy and binding energies of the evaporated particles are known. With approximate values for the above interactions, entropies, and binding energies, a probability distribution has been computed for the number of prongs per star. The results are in qualitative agreement with the observations on photographic emulsions described in Part 1.

Report presenting an investigation of the closed wind-tunnel phenomenon of choking and the wall-constriction effects in the subsonic Mach number range where supersonic Mach numbers appear using the hydraulic analogy. Application of the results to wind tunnel testing, the subsonic choking phenomena, and effects of the walls are described.

Report presenting an investigation to obtain the pressure distribution over a sharp-nose body of revolution with a circular-arc profile and fineness ratio 6 at transonic speeds using the NACA wing-flow method. Results regarding the variation of pressure coefficient with Mach number, pressure distributions along the body axis, pressure drag, and effects of interference and horizontal gradient are provided.

From Purpose of Report: "The purpose of the report is to point out what the mine-management official, the safety engineer, and the chemist, can do to utilize analyses of complex gas mixtures as basis for safe procedure to (1) control and extinguish fires in mines, tunnels, and individual plants and (2) prevent explosions when dealing with explosive mixtures and sources of ignition. The report is designed to meet the needs of those desiring to utilize analyses of complex-gas mixtures for the above-mentioned purpose."

Report issued by the Bureau of Mines over exploratory work conducted on the bauxite deposits of Arkansas. Descriptions of geophysical characteristics and core drilling results are presented. This report includes tables, maps, illustrations, and photographs.

Memorandum presenting an approximate subsonic theory developed for the solid blockage interference in circular wind tunnels with walls slotted in the direction of flow. The theory indicated the possibility of obtaining zero blockage interference. Tests in a circular slotted tunnel based on the theory confirmed the theoretical predictions.

The following report is a quarterly report done by the Physics Division of the University of California's Radiation Laboratory, covering the period of February 1, 1948 to May 1, 1948. This report discusses general physics research and the development and operation of the accelerator.

Report includes the National Advisory Committee for Aeronautics letter of submittal to the President, summaries of the committee's activities and research accomplished, bibliographies, and financial report.

Report presenting the analysis of the stability derivatives of low-aspect-ratio triangular wings at subsonic and supersonic speeds, which is extended to apply to triangular wings having large vertex angles and traveling at supersonic speeds.

The linear accelerator is again in operation after a shutdown fore repairs and minor changes. Radiofrequency checks of the instrument were made while the Van de Graaff was open. The vacuum of the system is now very good, the base pressure being 1.7 x 10{sup -6} mm Hg with a rate of rise of 800 s/{micro}s. Some preliminary results have been obtained on the activation of carbon with protons. The experiments were done using 10 mil, 50 mg/cm{sup 2} polystyrene discs. The activation curve obtained is shown. The break shown in the curve was found on two separate runs and it yet unexplained. In another experiment a proton induced activity in nickel was found. This had a 3.3 second half-life. Positive mesons have been detected on plates exposed in the 184-inch cyclotron with an arrangement shown schematically. The beam ws allowed to strike a 1/16 inch carbon target, and the mesons, which are bent around by the magnetic field, were detected with photographic plaes placed beneath the circulating beam. A series of experiments were done in which the plates were placed at distances varying from 1-1/2 to 3/4 inch from the beam between 1/4 inch plates of copper. The plates …

This is a monthly progress report on the following programs: (1) 184-inch Cyclotron; (2) 60-inch Cyclotron; (3) Synchrotron; (4) Linear Accelerator; (5) Experimental Physics; (6) Theoretical Physics; (7) Isotope Research; (8) Chemistry; (9) Medical Physics; and (10) Health Physics and Chemistry.

Report presenting the use of x-ray diffraction methods to identify the minor phases present in 20 high-temperature alloys in current use. The minor phases were noted in seven of the 20 alloys. A description of the relation of the alloys to one another and their chemical properties are provided.

Annual report submitted by the Boy Scouts of America to Congress describing highlights from 1947, activities, honors, finance. public relations, organizational leadership, and other information about scouting programs.

Report describing processes to prepare metallic calcium of a very high purity. Report details promising methods for electrolyte purification. Methods of chemical analysis for nitrogen are also improved upon and spectrochemical methods and standards established for twelve other specified elements.

From Abstract: "This report deals with an area of 425 square miles in the western part of Texas, immediately south of the New Mexico line. The report describes the geology of the area, that is, the nature of its rocks, tectonics, and surface features, and the evidence that they give as to the evolution of the area through geologic time. Incidental reference is made to the geology of surrounding regions in order to place the area in its environment."