Report discussing an analysis has been made by the NACA of the effects of heat and compressibility in the flow through the internal systems of aircraft along with equations and charts are developed whereby the flow characteristics at key stations in a typical internal system may be readily obtained.

"The Von Karman equations for a thin flat plate with large deflections are solved for the special case of a plate with clamped edges having a ratio of length to width of 1.5 and loaded by uniform normal pressure. Center deflections, membrane stresses, and extreme-fiber bending stresses are given as a function of pressure for center deflections up to twice the thickness of the plate. For small deflections the results coincide with those obtained by Hencky from the linear theory" (p. 1).

Report presenting an analytical study of the influence of full-span slotted and Fowler flaps on the requirements for horizontal tail surfaces. The elevator deflection required to land at three-point attitude, elevator deflection required to stall the airplane at altitude, and permissible center-of-gravity range have been calculated for a fighter-type airplane.

Report presenting the calibrations of three types of service pitot-static tubes over an approximate range of speeds of 150 to 600 miles per hour. The calibrations indicated a need for a pitot-static tube with greater accuracy, especially at higher speeds. Results regarding the service tubes, Prandtl tube, Eigh-speed tube, and a comparison of the tubes are provided.

Report presenting the results of comparative cooling tests run on two Wright C9GC (G-200) cylinders, one with the original steel fins and one with 1-inch spiral copper fins brazed on the barrel. Calculations were also performed using copper and aluminum fins with the same weight as the original steel fins, which showed positive results. Results regarding cylinder-temperature correlation, piston-temperature correlation, and comparative performance are also provided.

Describes the steps and equipment necessary for cotton ginning and for the prevention of seed mixing.

Report presenting a technique of testing wind tunnel powered models developed as a result of experience gained in the investigation of the static longitudinal and lateral staiblity and control characteristics of several powered models in the 7- by 10-foot wind tunnel. A discussion of the conditions to be investigated, methods of presenting and interpreting the data, and a suggested operating technique are given.

"The field for curved blades is represented by a vortex series with a vortex removed at the blade point. Further, an example of calculation of a curved blade from this series is given, whereby the necessary accuracy required of the different methods in practice is shown according to the case considered" (p. 1).

Describes the necessary steps for logging farm woodlands and transporting and preparing the wood to be sold.

Report discusses the results of an experimental investigation of two low-drag wing-nacelle units suitable for use with pusher propellers. The benefits of adding a nacelle to the wing are detailed.

Report presenting an investigation to determine whether some characteristic of the boundary layer could be used to provide warning of the increase in stalling speed of a wing caused by ice formations on the leading edge. Results were analyzed by referring the total pressures at the rake to the free-stream total pressure, static pressure at the rake, free-stream static pressure, and static pressure from wind-tip swiveling head.

Report presenting a study of the performance of bombers powered by one, two, four, and six 2000-horsepower engines supercharged to 25,000 feet. The performances are computed and are based on drag coefficients equal to the best obtained on modern airplanes and on weight estimates obtained from modern Army Air Forces airplanes. A chart is provided with the coordinates of power loading and wing loading noted so that all performances can be compared.

"In connection with recent tests of a 1/4-scale model pursuit airplane in the NACA 8-foot high-speed tunnel, gun openings having low drag were developed for installation in the nose of the fuselage. The increase in the fuselage-drag coefficient for the final form of openings was 0.0132 at a Mach number of 0.69 and at an angle of attack of 0 degrees. The corresponding drag coefficient based on the wing area was about 0.0005. The critical speed of the airplane was not affected by the gun openings" (p. 1).

Report presenting an investigation of means to increase the range of several airplanes to 6000 miles, including the B-17E, B-24D, B-26C, and B-25A. Tank-wing trailers and tank gliders were found to be the most practical ways of increasing range and calculations are provided for determining the proper loading and dimensions.

Describes the life cycle of the beanstalk weevil, its habits, and the damage it causes to plants in the Estancia Valley of New Mexico.

Report issued by the U.S. Bureau of Mines regarding laboratory tests conducted on acid leaching of manganese ore. Descriptions of the methods used in testing and results are presented. This report contains tables, and graphs.

Report presenting the results of recent spin-tunnel tests on models of seven multiengine airplanes and compared with corresponding results for representative single-engine airplanes loaded along the fuselage. Multiengine airplanes were found to give steep spins with high rates of descent and high load factors.

Front: Text describes action on various war fronts including Midway, Western Europe, Russia, Egypt, Southwest Pacific, Mediterranean, China, and Jugoslavia. Large world map is keyed to text and illustrates time zones around the world. Includes two inset maps: "Rommel drives east for Suez"; Nazi-Russian battles near Kursk. Photographs: Saboteurs' weapons, Port of embarkation, Allied leaders in the Middle East [Major Gen. Russell L. Maxwell, General Sir Claude Auchinleck], Armoured observation car, U.S. Army troops in shadow of the pyramids; British mechanized unit salvages a disabled tank; Blocking Nazi tanks;"Production hits its stride". Back: Poster features photographs of British weapons.

Text describes action on various war fronts: China, Russia, Western Europe, Southwest Pacific, Convoys, Egypt, Aleutians. Large world map is keyed to text and illustrates time zones around the world. Includes inset maps: The sixth year of war in the China provinces; The Russian central front; Battleground of the Middle East. Photographs: British gliders; Lady drivers; The FBI walked in; Royal inspection; Southwest fighting bases

Front: Text describes action on various war fronts: Russia, North Africa, Vichy fleet, Atlantic, Madagascar, Jugoslavia, Burma, China. Large world map is keyed to text and illustrates time zones around the world. Includes inset maps: Battle of Midway, Battleground in North Africa, Russian Front. Photographs: U.S. carrier is hit; Somewhere in Australia; Night bloom; Desert daybreak; Taken from Rommel; All-Chinese gun crew; Seagoing tractor on test; Ride through hell. Back: Text and illustrations promote the WEFT (Wing, Engine, Fuselage, Tail) method of aircraft recognition.

Front: Text describes action on various war fronts: Southwest Pacific, China, Aleutians, Atlantic, North Africa, Western Europe, Russia. Large world map is keyed to text and illustrates time zones around the world. Includes inset maps: China front, Russian front. Includes seven photographs. Back: Photographs show a variety of tanks utilized by the British Army.

Report presenting a new method for obtaining the velocity potential of the flow about a solid of revolution moving uniformly in the direction of its axis of symmetry in a fluid otherwise at rest. The method is based essentially on the fact that the form of the differential equation for the velocity potential is invariant with regard to conformal transformations in a meridian plane. The general results are applied to a body of revolution obtained by revolving a symmetrical Joukowski profile about its axis of symmetry.

Report presenting an investigation of the performance of a mixed-flow impeller and vaned diffuser unit with several modifications in a variable-component supercharger test rig. The investigation covered impeller tip speeds from 800 to 1200 feet per second over the range of air flows from wide-open throttle to incipient surge. The results showed the supercharger to have a peak efficiency of 0.77 and a peak pressure coefficient of 0.61 with the impeller frontal clearance at 0.035 inch.

Illustrations accompanying a report investigating the locations of vanadium-bearing phosphatic shale in West-Central Wyoming and Southeastern Idaho. The set includes seven maps (Plates I and V-X) showing the location of rock formations in the area and three charts (Plates II-IV) showing the correlation between the occurrence of vanadium deposits and the thin persistent beds of phosphate rock, oolite, siltstone, dolomite, and limestone with which they are interbedded.