"A flight test was made to determine the servoplane effectiveness and stability characteristics of the free-floating horizontal stabilizer to be used on the XF10F airplane. The results of this test indicate that servoplane effectiveness is practically constant through the speed range up to a Mach number of 1.15, and the stabilizer static stability is satisfactory. A loss of damping occurs over a narrow Mach number range near M = 1.0, resulting in dynamic instability of the stabilizer in this narrow range" (p. 1).

From Introduction and Summary: "This paper gives results of an investigation of the composition and carbonizing properties of coals from Pocahontas No.3 bed, Lake superior No.4 mine, McDowell County, W.Va.; Eagle bed, Cannelton No.3 mine, Fayette County, W.Va; and No.2 Gas bed, Cannelton No.100 mine, Kanawha County, W. Va."

From Forward: "The value of this survey of the carbonizing properties of American coals by a standard method lies in the comparability of the results on different coals. It must recognized that no standard laboratory method of carbonization, even on a large unit, can yield results that exactly duplicate those obtained in ovens and retorts. The commercial results vary with the type of oven or retort. Allowance must be made for such differences in interpreting the BM-AGA test results in terms of commercial plants."

From Introduction and Summary: "However, with the completion and satisfactory performance of an experimental vertical slot oven of 500-pound capacity at the University of Illinois Geological Survey Laboratory, the opportunity to directly compare BM-AGA coke with coke made by two-sided heating became available and the necessary test apparatus was installed. This report compares the results obtained by the two methods."

From Introduction: "Problems connected with incidence, effects, determination, and control of dusts are still much before the public, although more information is available to the layman than when Bulletin 400, of which this publication is a revision, was issued in 1937. This revision includes data that have accumulated since 1937 and some that appeared previous thereto but were not available to the authors at that time."

Through theoretical and analog results the effects of two nonlinear stability derivatives on the longitudinal motions of an aircraft have been investigated. Nonlinear functions of pitching-moment and lift coefficients with angle of attack were considered. Analog results of aircraft motions in response to step elevator deflections and to the action of the proportional control systems are presented. The occurrence of continuous hunting oscillations was predicted and demonstrated for the attitude stabilization system with proportional control for certain nonlinear pitching-moment variations and autopilot adjustments.

Note presenting a flight investigation of a three-blade propeller in climb and at high speed to determine the effects of blade power loading. Increasing the blade power coefficient from 0.06 to 0.09 was found to increase the efficiency approximately 8 percent at an airplane Mach number of 0.7 and a propeller-tip Mach number of 1.13. In climb, an increase in power loading over the range of blade power coefficients investigated was shown to reduce efficiency, as a consequence of increased induced drag losses.

Memorandum presenting an investigation of the effects of compressibility on the forces, pitching moments, and surface pressures on a wing-nacelle combination. The leading edge of the wing was swept back 37.25 degrees and the nacelle was a body of revolution with a fineness ratio of 6.5. The effects of compressibility on the surface pressures and on the drag of a body of revolution similar to the nacelle were also determined.

Report issued by the U.S. Bureau of Mines describing the methods and equipment developed at the oil-shale mine near Rifle, Colorado. This report includes photographs and illustrations documenting this equipment.

Report presenting an analysis of the time-dependent downwash behind a wing in a supersonic stream when the angle of attack varies linearly with time. The result is applied to the calculation of the contribution of the horizontal tail to the pitching moment and lift due to normal acceleration of the airplane. Results regarding downwash charts and some limitations on the results are provided.

Report documenting the suitability of Nevada for plant locations to produce synthetic liquid fuels, based on raw materials, water sources, and local interest.

From Introduction: "The design of turbojet-engine control systems is intimately related to the dynamic characteristics of the engine and has advanced to the stage where theoretically correct control constants can be determined for fixed dynamic properties (references 1 and 2). The use of the thermodynamic equations presupposes that the engine processes are quansi-static. Such an assumption is shown to be valid for a turbojet engine in references 3 and 4.

Report presenting an investigation of the use of the transonic similarity law for two-dimensional flow by an iteration procedure. The results indicated that potential can be expressed as a power series in a single parameter that depends on Mach number, thickness ratio, and ratio of specific heats.

A report regarding uranium occurrences in the white canyon Area, San Juan County, Utah.

In an effort to gain information on the nature of the photon-meson and photon-nucleon interaction, a study of the artificial production of mesons by photons has been made at the Berkeley synchrotron. The major effort of this research was concentrated on a measurement of the energy and angular distribution of u+-mesons produced when the photons strike a target of liquid hydrogen. Detection of the mesons is accomplished electronically by the technique of delayed coincidence.

Note presenting the application of the Laplace transformation to the solution of the lateral and longitudinal stability equations. The expressions for the time history of the motion in response to a sinusoidal control motion are derived for the general case in which all initial measurements are assumed different from zero.

Report discussing an investigation of two transonic research airplane models at a range of Mach numbers and Reynolds numbers. The main difference between the models was the aspect ratio of the horizontal tail. Results regarding the stability, control, incremental horizontal-tail characteristics, downwash, horizontal-tail load, stability factors, and a tailless configuration are provided.

"A summary of methods for making dynamic lateral stability and response calculations and for estimating the aerodynamic stability derivatives required for use in these calculations is presented. The processes of performing calculations of the time histories of lateral motions, of the period and damping of these motions, and of the lateral stability boundaries are presented as a series of simple straightforward steps. Existing methods for estimating the stability derivatives are summarized and, in some cases, simple new empirical formulas are presented. Detailed estimation methods are presented for low-subsonic-speed conditions but only a brief discussion and a list of references are given for transonic and supersonic speed conditions" (p. 1).