Circular describing the Vickers Viastra I, which is a commercial high-wing all-metal semicantilever monoplane. Details of the structure, fuselage, wings, fuel tanks, landing gear, tail, cabin, cockpit, characteristics, drawings, and photographs are provided.

In this mathematical investigation, made in collaboration with Dr. Wilhelm Schmidt, we interpret the temporary change (due to some disturbance) in the quantities which define the position of the airplane while in a flat spin. We further examine the effect of this change, of the means resorted to to produce the disturbance, and thus reveal the expedients available for recovering from a flat spin.

Study of the bending stress in smooth skin, aluminum alloy, true monocoque fuselage sections of varying ratio of diameter to thickness.

Report issued by the U.S. Bureau of Mines on laboratory testing developed to measure the slacking of coals. Testing methods and results are presented. This report includes tables and graphs.

The tests, conducted at the Guggenheim Aeronautical Laboratory of Stanford University, to investigate the phenomenon of separation in the air flow past geometric shapes are described in this report.

The tests herein reported were conducted by the NACA to determine the effect of the angular position of the section of a ring cowling on the speed of an airplane having a radial air-cooled engine.

"The penetration and cone-angle of fuel sprays from open nozzles were recorded with the NACA Spray Photography Equipment. The results show that for injection systems in which the rate of pressure rise at the discharge orifice is high, open nozzles give spray-tip velocities and penetrations which compare favorably with those of closed nozzles. The spray cone-angle was the same for all tests, although open nozzles having different orifice diameters were used, and one nozzle was used both as an open and as a closed nozzle" (p. 1).

Describes uses for lamb meat in meals; provides recipes and methods for its preparation in various dishes.

Describes the natural soils where pecan trees grow and the different types of fertilizers used to improve the soils.

"For some time the D.V.L. has been investigating the question of applicability of Handley Page slotted wings to German airplanes. Comparitive gliding tests were made with open and closed slots on an Albatros L 75 airplane equipped with the Handley Page "auto control slots." This investigation served to determine the effect of the auto control slot on the properties and performances of airplanes at large angles of attack. The most important problems were whether the angle of glide at small angles of attack can be increased by the adoption of the auto control slot and, in particular, as to whether the flight characteristics at large angles of attack are improved thereby and equilibrium in gliding flight is guaranteed even at larger than ordinary angles of attack" (p. 1).

"The effect of a slotted wing depends essentially on the fact that a secondary flow branches off from the main flow and passes to the suction side of the profile. It is thus possible to delay the separation greatly and increase the lift. The practical aspect of the slotted wing is less known in Germany, especially the results obtained during the last three years since the introduction of the 'auto control slot'" (p. 1).

This paper presents a relative determination of the wrinkling of a plate wall beam with variable number of supports and methods of attachment. The discussion is based entirely on tests with extensometer readings and number of wrinkles, with complete web and with cutout sections. The author notes that the number of corrugations increase with added stress, keeping constant edge spacing.

The method of riveting by forming the closing head under increasing pressure or by a series of hammer blows is investigated. The question as to the best edge distance, i.e. that distance from the rivet center to the plate edge below which it is unadvisable to go and, at the same time useless to go beyond, was examined. The slippage of plates which occurs under the effect of a certain stress, does not completely disappear on unloading.

This report describes tests of 10 full-scale metal propellers of several thickness ratios at various tip speeds up to 1,350 feet per second. The results indicate no loss of efficiency up to tip speeds of approximately 1,000 feet per second. Above this tip speed the loss is at a rate of about 10 per cent per 100 feet per second increase relative to the efficiency at the lower speeds for propellers of pitch diameter ratios 0.3 to 0.4. Propellers having sections of small thickness ratio can be run at slightly higher speeds than thick ones before beginning to lose efficiency.

Agriculture bulletin that includes the varietal purity certification. This bulletin also includes certification laws, rules and regulations, and instructions that are relative to enforcement.