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Blueberries.

Description: Discusses aspects of blueberry production in the United States from planting through harvesting and marketing, and examines different types of blueberries.
Date: October 1940
Creator: Darrow, George M. (George McMillan), 1889-
Item Type: Book

Boundary-Layer Transition on the N.A.C.A. 0012 and 23012 Airfoils in the 8-Foot High-Speed Wind Tunnel, Special Report

Description: Determinations of boundary-layer transition on the NACA 0012 and 2301 airfoils were made in the 8-foot high-speed wind tunnel over a range of Reynolds Numbers from 1,600,000 to 16,800,000. The results are of particular significance as compared with flight tests and tests in wind tunnels of appreciable turbulence because of the extremely low turbulence in the high-speed tunnel. A comparison of the results obtained on NACA 0012 airfoils of 2-foot and 5-foot chord at the same Reynolds Number permitted an evaluation of the effect of compressibility on transition. The local skin friction along the surface of the NACA 0012 airfoil was measured at a Reynolds Number of 10,000,000. For all the lift coefficient at which tests were made, transition occurred in the region of estimated laminar separation at the low Reynolds Numbers and approach the point of minimum static pressure as a forward limit at the high Reynolds Numbers. The effect of compressibility on transition was slight. None of the usual parameters describing the local conditions in the boundary layer near the transition point served as an index for locating the transition point. As a consequence of the lower turbulence in the 8-foot high-speed tunnel, the transition points occurred consistently farther back along the chord than those measured in the NACA full-scale tunnel. An empirical relation for estimating the location of the transition point for conventional airfoils on the basis of static-pressure distribution and Reynolds Number is presented.
Date: January 1, 1940
Creator: Becker, John V.
Item Type: Report

Breaking and training colts.

Description: Describes methods training horses for farm use. Includes training or control methods for driving, riding, shoeing, and throwing.
Date: 1940
Creator: Stamburgh, V. G. (Vivian Guy), 1885-; Williams, J. O. (John Oscar), 1885- & Krantz, Earl B. (Earl Beach), 1893-
Item Type: Book

Buckling tests with a spar-rib grill

Description: The present report deals with a comparison of mathematically and experimentally defined buckling loads of a spar-rib grill, on the assumption of constant spar section, and infinitely closely spaced ribs with rigidity symmetrical to the grill center. The loads are applied as equal bending moments at both spar ends, as compression in the line connecting the joints, and in the spar center line as the assumedly uniformly distributed spar weight.
Date: September 1, 1940
Creator: Weinhold, Josef
Item Type: Report

Business records for poultry keepers.

Description: Describes business methods to help poultry keepers with their production and marketing issues, discusses record-keeping methods, and includes suggestions to improve efficiency of a farmer's poultry business.
Date: 1940
Creator: Johnson, E. R. (Ernest Reuben), 1892- & Lee, Alfred R., b. 1887.
Item Type: Book

The calculated effect of various hydrodynamic and aerodynamic factors on the take-off of a large flying boat

Description: Report presents the results of an investigation made to determine the influence of various factors on the take-off performance of a hypothetical large flying boat by means of take-off calculations. The factors varied in the calculations were size of hull (load coefficient), wing setting, trim, deflection of flap, wing loading, aspect ratio, and parasite drag. The take-off times and distances were calculated to the stalling speeds and the performance above these speeds was separately studied to determine piloting technique for optimum take-off.
Date: January 1, 1940
Creator: Olson, R E & Allison, J M
Item Type: Report

Care and management of farm work horses.

Description: Describes how to successfully manage and care for work horses on the farm to maximize serviceability and profitability.
Date: March 1940
Creator: Williams, J. O. (John Oscar), 1885- & Krantz, Earl B. (Earl Beach), 1893-
Item Type: Book

Cattle-Fever Ticks and Methods of Eradication

Description: Revised edition. This bulletin discusses the cattle-fever tick and methods for controlling it. Possible methods include dipping, pasture rotation, and arsenical dips. The life history of the tick is also discussed and instructions for constructing a concrete vat are given.
Date: 1940
Creator: Ellenberger, W. P. & Chapin, Robert M.
Item Type: Pamphlet

The cause of welding cracks in aircraft steels

Description: The discussion in this article refers to gas welding of thin-walled parts of up to about 3 mm thickness. It was proven that by restricting the sulphur, carbon, and phosphorous content, and by electric-furnace production of the steel, it was possible in a short time to remove this defect. Weld hardness - i.e., martensite formation and hardness of the overheated zone - has no connection with the tendency to weld-crack development. Si, Cr, Mo, or V content has no appreciable effect, while increased manganese content tends to reduce the crack susceptibility.
Date: October 1, 1940
Creator: Muller, J
Item Type: Report

Celery growing.

Description: A guide to commercial celery-growing, with brief instructions for growing celery in home gardens. Includes descriptions of celery diseases and insect pests.
Date: 1940
Creator: Beattie, W. R. (William Renwick), b. 1870.
Item Type: Book

Chordwise load distribution of a simple rectangular wing

Description: The chordwise distribution theory was taken over from the theory of the infinite wing. Since in this work a series expansion in b/t was used, the computation converges only for large aspect ratios. In this paper a useful approximate solution will be found also for wings with large chord - i.e., small aspect ratio.
Date: December 1, 1940
Creator: Wieghardt, Karl
Item Type: Report

Clothes moths.

Description: Describes the life cycle and characteristics of clothes moths, and methods for their control.
Date: January 1940
Creator: Back, E. A. (Ernest Adna), 1886-
Item Type: Book

Coal-Mine Accidents in the United States, 1937

Description: Report compiled by the U.S. Bureau of Mines including statistics on fatal and non-fatal accidents in coal mines located in the United States as well as data regarding the various operations (e.g., number of miners employed and average production). The information is organized into tables for comparison and the text draws some overall conclusions in the summary.
Date: 1940
Creator: Adams, William W.; Geyer, L. E. & Parry, M. G.
Item Type: Report

Comparison of Three Exit-Area Control Devices on an N.A.C.A. Cowling, Special Report

Description: Adjustable cowling flaps, an adjustable-length cowling skirt, and a bottom opening with adjustable flap were tested as means of controlling the rate of cooling-air flow through an air-cooled radial-engine cowling. The devices were tested in the NACA 20-foot tunnel on a model wing-nacelle-propeller combination, through an airspeed range of 20 to 80 miles per hour, and with the propeller blade angle set 23 degrees at 0.75 of the tip radius. The resistance of the engine to air flow through the cowling was simulated by a perforated plate. The results indicated that the adjustable cowling flap and the bottom opening with adjustable flap were about equally effective on the basis of pressure drop obtainable and that both were more effective means of increasing the pressure drop through the cowling than the adjustable-length skirt. At conditions of equal cooling-air flow, the net efficiency obtained with the adjustable cowling flaps and the adjustable-length cowling skirt was about 1% greater than the net efficiency obtained with the bottom opening with adjustable flap.
Date: May 1, 1940
Creator: McHugh, James G.
Item Type: Report

Constant-pressure blowers

Description: The conventional axial blowers operate on the high-pressure principle. One drawback of this type of blower is the relatively low pressure head, which one attempts to overcome with axial blowers producing very high pressure at a given circumferential speed. The Schicht constant-pressure blower affords pressure ratios considerably higher than those of axial blowers of conventional design with approximately the same efficiency.
Date: January 1, 1940
Creator: Sorensen, E.
Item Type: Report

Corn culture.

Description: A general guide to growing corn crops in the United States, including selection, land preparation, planting, culture, and insect and disease control.
Date: 1940
Creator: Richey, Frederick D. (Frederick David), b. 1884.
Item Type: Book

Corrections on the thermometer reading in an air stream

Description: A method is described for checking a correction formula, based partly on theoretical considerations, for adiabatic compression and friction in flight tests and determining the value of the constant. It is necessary to apply a threefold correction to each thermometer reading. They are a correction for adiabatic compression, friction and for time lag.
Date: October 1, 1940
Creator: Van Der Maas, H J & Wynia, S
Item Type: Report

Correlation of cooling data from an air-cooled cylinder and several multicylinder engines

Description: The theory of engine-cylinder cooling developed in a previous report was further substantiated by data obtained on a cylinder from a Wright r-1820-g engine. Equations are presented for the average head and barrel temperatures of this cylinder as functions of the engine and the cooling conditions. These equations are utilized to calculate the variation in cylinder temperature with altitude for level flight and climb. A method is presented for correlating average head and barrel temperatures and temperatures at individual points on the head and the barrel obtained on the test stand and in flight. The method is applied to the correlation and the comparison of data obtained on a number of service engines. Data are presented showing the variation of cylinder temperature with time when the power and the cooling pressure drop are suddenly changed.
Date: January 1, 1940
Creator: Pinkel, Benjamin & Ellerbrock, Herman H., Jr.
Item Type: Report