Describes methods for separating weeds from grain in order to improve value and quality.

Describes the symptoms, possible causes, and prevention of an infectious abortion disease affecting cattle.

A guide to growing shortleaf pine trees as a timber crop.

"Tests have been made by the National Advisory Committee for Aeronautics on the air flow in an open jet wind tunnel with various sizes, shapes, and spacings of cones, and the flow studied by means of velocity and direction surveys in conjunction with flow pictures. It was found that for all combinations of cones tested the flow is essentially the same, consisting of an inner core of decreasing diameter having uniform velocity and direction, and a boundary layer of more or less turbulent air increasing in thickness with length of jet. The energy ratio of the tunnel was obtained for the different combinations of cones, and the spilling around the exit cone causing undesirable air currents in the experiment chamber was noted" (p. 1).

Strips of german silver, steel, copper, duralumin, nickel and brass were tested in tension in an apparatus in which the change in deflection with time was measured by means of an interferometer. This change in deflection with time caused by the application and removal of a load is defined as "drift" and "recovery," respectively. It was measured in the time interval from approximately 5 seconds to 5 hours after loading. The data are given in a series of graphs in which the drift and recovery are plotted against time. The proportional drift and recovery in five hours are given for a number of the tests, and in addition are shown graphically for nickel and steel.

"The saving of time that results from flying across country on compass headings is beginning to be widely recognized. At the same time the general use of steel tube fuselages has made a knowledge of compass correction much more necessary than was the case when wooden fuselages were the rule. This paper has been prepared primarily for the benefit of the pilot who has never studied navigation and who does not desire to go into the subject more deeply than to be able to fly compass courses with confidence" (p. 1).

The ultimate test of a load factor formula is experience. The chief advantages of a semi rational formula over arbitrary factors are that it fairs in between points of experience and it differentiates according to variables within a type. Structural failure of an airplane apparently safe according to the formula would call for a specific change in the formula. The best class of airplanes with which to check a load factor formula seems to be those which have experienced structural failure. Table I comprises a list of the airplanes which have experienced failure in flight traceable to the wing structure. The load factor by formula is observed to be greater than the designed strength in each case, without a single exception. Table II comprises the load factor by formula with the designed strength of a number of well-known service types. The formula indicates that by far the majority of these have ample structural strength. One case considered here in deriving a suitable formula is that of a heavy load carrier of large size and practically no reserve power.

Described here is a new corrosion resistant aluminum product which is markedly superior to the present strong alloys. Alclad is a heat-treated aluminum, copper, manganese, magnesium alloy that has the corrosion resistance of pure metal at the surface and the strength of the strong alloy underneath. Of particular importance is the thorough character of the union between the alloy and the pure aluminum.

The three engine Junkers commercial Airplane, type G 31 is a further development of the earlier G 24. It is an all metal low wing monoplane with a total engine output of 1100-1200 HP.

Memorandum describing the flights of Charles Lindbergh and some of the calculations that go into the determination of the amount of fuel required, drag, and weight for his trip.

The results of the velocity measurements in the boundary layer described in NACA-TM 411 are here discussed in greater detail. The measurements made were of the velocity distribution in the vicinity of an airfoil model fitted with a rotary cylinder and were undertaken for the purpose of obtaining a closer insight into the phenomena observed in experimenting with this model.

This part of the report presents characteristics and graphic representations of water resistance. The laws of similarity are discussed as well as the theory of model tests. The test procedures and model tests of other countries are also discussed.

Scientific paper issued by the Bureau of Standards over studies conducted on radio fading. As stated in the abstract, "the series of measurements on fading were devoted to studies of fading effects during the sunset period, effects during the solar eclipse of January 24, the fading variations throughout a 24-hour day, and the effects of high transmitting power on fading" (p. 419). This paper includes tables, maps, illustrations, and photographs.

Different methods for increasing the efficiency of diesel engines are presented and some new designs are given.

The Boeing Mail Airplane is a biplane with cloth covered wings of wood and wire construction, a top speed of 130 MPH, and a fuel capacity of 100 gallons in two tanks.

The Caproni 73 is a biplane with medium thick wings, a rigid central section, and with each lateral extension forming a single cell and is powered by two 500 Isotta Fraschini "Asso" Engines.

Circular describing the Levasseur 8, which is an adaptation of a naval airplane adopted by the French Navy. Details of the wings, fuselage, landing gear, fuel, engine, and flying qualities are provided.

The Widgeon III is a parasol type monoplane. One of its strongest features was the high degree of visibility available to the pilot. A description of the design, construction, flight characteristics, blueprints, and photographs are provided.

Bulletin outlining information regarding vegetable growing and marketing, organized by types of crops. It includes information about each stage of cultivation such as acquiring and planting seeds, transplanting seedlings, water and soil, harvests, and distribution to markets.

Document containing additional statistical, agricultural and livestock matter, with a supplement giving each Department of the State Government, including the Eleemosynary and Educational Institutions and the Judicial Department. It also gives the names of heads of the different State Departments and State Institutions, together with the number of employees and the appropriations for support of each.

Agriculture bulletin listing names of licensed nureserymen, florists, and dealers licensed to do business in the state of Texas. Also includes Texas orchard and nursery inspection law with rules and regulations as enacted in 1927.