Brief summary of the physical characteristics, general habits, breeding habits, food habits, migratory habits, and habitat of the Alaska-Yukon caribou.

"The paper beings with a brief discussion on the origin of the bending stresses in cantilever box beams under torsion. A critical survey of existing theory is followed by a summary of design formulas; this summary is based on the most complete solution published but omits all refinements considered unnecessary at the present state of development. Strain-gage tests made by NACA to obtained some experimental verification of the formulas are described next. Finally, the formulas are applied to a series of box beams previously static-tested by the U.S. Army Air Corps; the results show that the bending stresses due to torsion are responsible to a large extent for the free-edge type of failure frequently experienced in these tests" (p. 1).

"In determining the effect of turbulence on the forces exerted on bodies in the air stream of a wind tunnel, it is commonly assumed that the indications of the standard Pitot-static tube used to determine the air speed are not dependent on the turbulence. To investigate the truth of this assumption, the drag of a normally exposed flat plate, the difference in pressure between the front and rear of a thin circular disk, the rate of rotation of a vane anemometer, and the pressure developed by a standard Pitot-static tube were measured in an air stream for several conditions of turbulence. The results may be interpreted as indicating that there is no appreciable effect of turbulence on the vane anemometer and the standard pitot-static tube, but that there is small effect on the drag of a flat plate and the pressure difference between front and rear of a disk" (p. 129).

Oxygen regulators are used in aircraft to regulate automatically the flow of oxygen to the pilot from a cylinder at pressures ranging up to 150 atmospheres. The instruments are adjusted to open at an altitude of about 15,000 ft. and thereafter to deliver oxygen at a rate which increases with the altitude. The instruments are tested to determine the rate of flow of oxygen delivered at various altitudes and to detect any mechanical defects which may exist.

From Summary: "A rigorous treatment is given of the problem of determining the two-dimensional potential flow around arbitrary biplane cellules. The analysis involves the use of elliptic functions and is sufficiently general to include the effects of such elements as the section shapes, the chord ratio, gap, stagger, and decalage, which elements may be specified arbitrarily. The flow problem is resolved by making use of the methods of conformal representation. Thus the solution of the problem of transforming conformally two arbitrary contours into two circles is expressed by a pair of simultaneous integral equations, for which a method of numerical solution is outlined."

"The NACA model 11-G flying-boat hull, a modification of NACA model 11-A was tested over a range of loadings. The planing bottom of model 11-G has a variable-radius flare, or concavity, at the chines in contrast to the straight V planing bottom of model 11-A. The results are given as curves of resistance and trimming moment plotted against speed for various angles of trim" (p. 1).

From Summary: "The NACA model 40 series of flying-boat hull models consists of 2 forebodies and 3 afterbodies combined to provide several forms suitable for use in small marine aircraft. One forebody is the usual form with hollow bow sections and the other has a bottom surface that is completely developable from bow to step. The afterbodies include a short pointed afterbody with an extension for the tail surfaces, a long afterbody similar to that of a seaplane float but long enough to carry the tail surfaces, and a third obtained by fitting a second step in the latter afterbody."

Report presenting an examination of the thermodynamics of combustion in the Otto cycle engine, including the effects of turbulence and some of the possible causes of detonation within an engine.

"The theory of wind tunnel boundary influence on the downwash from a wing has been extended to provide more complete corrections for application to airplane test data. The first section of the report gives the corrections of the lifting line for wing positions above or below the tunnel center line; the second section shows the manner in which the induced boundary influence changes with distance aft of the lifting line. Values of the boundary corrections are given for off-center positions of the wing in circular, square, 2:1 rectangular, and 2:1 elliptical tunnels" (p. 135).