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Compressibilities of gases

Description: Reproduction of thirteen graphs for computing compressibilities of various gases and for computing the volumes delivered from cylinders containing various gases.
Date: November 21, 1925
Creator: Pickering, Samuel Fisher
Partner: UNT Libraries Government Documents Department

A method for the direct determination of wing-section drag

Description: In order that the method may be more easily understood, we will first consider the simpler case when there is no lift, but only drag, and when the streamlines at the measuring point behind the obstacle are nearly parallel. Moreover, the flow is assumed not to deviate much from the two-dimensional flow.
Date: November 1925
Creator: Betz, A.
Partner: UNT Libraries Government Documents Department

Air flow investigation for location of angle of attack head on a JN4h airplane

Description: The technical staff of the NACA at Langley Field, has made a series of free flight tests with a JN4h airplane in order to find the best place for an instrument for measuring the angle of attack. A "neutral zone" was found where the air remains either at rest relative to the undisturbed air beyond the influence of the airplane, or is set in motion parallel to the motion of the airplane. This zone is about midway between the two wings and slightly in front of, or at the vertical plane through the leading edges of the wings but the exact position as well as the outlines of the zone varies considerably as the conditions of flight change.
Date: August 1925
Creator: Freeman, R. G.
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics of airfoils at high speeds

Description: From Summary: "This report deals with an experimental investigation of the aerodynamical characteristics of airfoils at high speeds. Lift, drag, and center of pressure measurements were made on six airfoils of the type used by the air service in propeller design, at speeds ranging from 550 to 1,000 feet per second. The results show a definite limit to the speed at which airfoils may efficiently be used to produce lift, the lift coefficient decreasing and the drag coefficient increasing as the speed approaches the speed of sound. The change in lift coefficient is large for thick airfoil sections (camber ratio 0.14 to 0.20) and for high angles of attack. The change is not marked for thin sections (camber ratio 0.10) at low angles of attack, for the speed range employed. At high speeds the center of pressure moves back toward the trailing edge of the airfoil as the speed increases. The results indicate that the use of tip speeds approaching the speed of sound for propellers of customary design involves a serious loss in efficiency."
Date: 1925~
Creator: Briggs, L. J.; Hull, G. F. & Dryden, H. L.
Partner: UNT Libraries Government Documents Department

Comparison of model propeller tests with airfoil theory

Description: The purpose of the investigation covered by this report was the examination of the degree of approach which may be anticipated between laboratory tests on model airplane propellers and results computed by the airfoil theory, based on tests of airfoils representative of successive blade sections. It is known that the corrections of angles of attack and for aspect ratio, speed, and interference rest either on experimental data or on somewhat uncertain theoretical assumptions. The general situation as regards these four sets of corrections is far from satisfactory, and while it is recognized that occasion exists for the consideration of such corrections, their determination in any given case is a matter of considerable uncertainty. There exists at the present time no theory generally accepted and sufficiently comprehensive to indicate the amount of such corrections, and the application to individual cases of the experimental data available is, at best, uncertain. While the results of this first phase of the investigation are less positive than had been hoped might be the case, the establishment of the general degree of approach between the two sets of results which might be anticipated on the basis of this simpler mode of application seems to have been desirable.
Date: 1925
Creator: Durand, William F. & Lesley, E. P.
Partner: UNT Libraries Government Documents Department

Characteristics of a single float seaplane during take-off

Description: At the request of the Bureau of Aeronautics, Navy Department, the National Advisory Committee for Aeronautics at Langley Field is investigating the get-away characteristics of an N-9H, a DT-2, and an F-5l, as representing, respectively, a single float, a double float, and a boat type of seaplane. This report covers the investigation conducted on the N-9H. The results show that a single float seaplane trims aft in taking off. Until a planing condition is reached the angle of attack is about 15 degrees and is only slightly affected by controls. When planing it seeks a lower angle, but is controllable through a widening range, until at the take-off it is possible to obtain angles of 8 degrees to 15 degrees with corresponding speeds of 53 to 41 M. P. H. or about 40 per cent of the speed range. The point of greatest resistance occurs at about the highest angle of a pontoon planing angle of 9 1/2 degrees and at a water speed of 24 M. P. H.
Date: January 1925
Creator: Crowley, J. W., Jr. & Ronan, K. M.
Partner: UNT Libraries Government Documents Department

Determination of turning characteristics of an airship by means of a camera obscura

Description: This investigation was carried out by the National Advisory Committee at Langley Field for the purpose of determining the adaptability of the camera obscura to the securing of turning characteristics of airships, and also of obtaining some of those characteristics of the C-7 airship. The method consisted in flying the airship in circling flight over a camera obscura and photographing it at known time intervals. The results show that the method used is highly satisfactory and that for the particular maneuver employed the turning diameter is 1,240 feet, corresponding to a turning coefficient of 6.4, and that the position of zero angle of yaw is at the nose of the airship.
Date: 1925
Creator: Crowley, J. W., Jr. & Freeman, R. G.
Partner: UNT Libraries Government Documents Department

Simplified propeller design for low-powered airplanes

Description: The object of this report is to furnish the designer and builder of small airplanes a simple system for designing the propeller and making the drawing. An empirical design method is used, based on tests of model propellers in a wind tunnel and full scale tests of propellers in flight.
Date: January 1, 1925
Creator: Weick, Fred E.
Partner: UNT Libraries Government Documents Department

Some problems on the lift and rolling moment of airplane wings

Description: This report deals with the application of the airfoil and twisted wing theory to the calculation of the lift and rolling moment of airplane wings. Most of the results arrived at are strictly true only for wings of elliptic plan form. The investigation aims to give some indications of the accuracy with which the results can be applied to the wing forms in actual use.
Date: January 1, 1925
Creator: Scarborough, James B
Partner: UNT Libraries Government Documents Department

The Legendary "White Metal" and its "Ore"

Description: Report concerning stories about claims of a "white metal" extracted from an "ore" found packed around pieces of iron or steel. It includes information about various tests conducted about the validity of these claims and their findings.
Date: December 1925
Creator: Davis, C. W.
Partner: UNT Libraries Government Documents Department

Motor-Vehicle Headlighting

Description: A report on the necessity of improved motor-vehicle lighting.
Date: August 5, 1925
Creator: Carlson, R. E.
Partner: UNT Libraries Government Documents Department

Coal-Mine Fatalities in the United States, 1924

Description: Report compiled by the U.S. Bureau of Mines including statistics on fatalities 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: 1925
Creator: Adams, William W.
Partner: UNT Libraries Government Documents Department

Review of Safety and Health Conditions in the Mines at Butte

Description: From Introduction: "This review of safety and health conditions in the mines of Butte, Mont., is prepared from data gathered during the period 1916 to 1924, inclusive, chiefly by Daniel Harrington, who was until recently supervising mining engineer of the Bureau of Mines."
Date: 1925
Creator: Rice, G. S. & Sayers, R. R.
Partner: UNT Libraries Government Documents Department

Garnet: Its Mining, Milling, and Utilization

Description: From Introduction: "This bulletin presents the results of an investigation conducted by the Bureau of Mines as part of its work for the increase of efficiency and the prevention of waste in the mineral industries."
Date: 1925
Creator: Myers, W. M. & Anderson, C. O.
Partner: UNT Libraries Government Documents Department

Surface Machinery and Methods for Oil-Well Pumping

Description: From Introduction General Scope: "This bulletin deals with prime movers, power-transmitting machinery, and the surface equipment and methods used to pump oil wells."
Date: 1925
Creator: George, H. C.
Partner: UNT Libraries Government Documents Department

The Metallurgy of Quicksilver

Description: From General Conclusions: "The main conclusions to be drawn from the work discussed in this bulletin may be summarized as follows: In the direct-furnace treatment of quicksilver ores the major problem in the extraction of quicksilver has been solved. Methods are available whereby low-grade ore can be treated with a remarkably high recovery and at low cost in view of small scale of operations at most plants."
Date: 1925
Creator: Duschak, L. H. & Schuette, C. N.
Partner: UNT Libraries Government Documents Department

Protection of Oil and Gas Field Equipment Against Corrosion

Description: From Introduction: "This bulletin describes common causes and effects of oil and gas field corrosion and outlines methods of abating the damage."
Date: 1925
Creator: Mills, R. Van A.
Partner: UNT Libraries Government Documents Department

Screen Sizing of Coal, Ores and Other Minerals

Description: From Introduction: "The data in this bulletin were obtained during an investigation of screening practice by the University of Illinois engineering experiment station and the United States Bureau of Mines under a cooperative agreement between them and the State of Illinois Geographical Survey Division. The present investigation was limited to a study of screening as applied in preparing mineral products with the expectation of obtaining more comprehensive information on screening machinery."
Date: 1925
Creator: Holbrook, E. A. & Fraser, Thomas
Partner: UNT Libraries Government Documents Department

Mine Timber: Its Selection, Storage, Treatment, and Use

Description: From Introduction Purpose and Scope of Bulletin: "The purpose of this bulletin is to point out some of the benefits and economies to be derived by selecting, preparing, storing, pre-serving, and utilizing mine timber more carefully and to give some specific information on certain preservatives and processes suitable for mine timber."
Date: 1925
Creator: Hornor, R. R. & Tufft, Harry E.
Partner: UNT Libraries Government Documents Department