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Geology of the Santa Rita Mining Area, New Mexico

Description: From abstract: The Santa Rita mining area (pl. 1), covering 35 square miles of semiarid mountainous land, lies within the Silver City 30-minute quadrangle, Grant County, N. Mex., and includes the most productive part of the Central or Hanover mining district. Ore was produced in this district as early as 1804 and production continued intermittently for a century before the developments were undertaken that led to large-scale copper mining, which began in 1912. The output of zinc, lead, and iron increased markedly about the same time.
Date: 1935
Creator: Spencer, Arthur C. & Paige, Sidney
Partner: UNT Libraries Government Documents Department

The Contact Mining District, Nevada

Description: From abstract: This report summarizes the results of a reexamination, in 1930, of the Contact mining district, in Elko County, northern Nevada. A report published as a result of a visit in 1910 summarizes the major features of the geology of the district, and the principal new data in the present paper pertain to mining development occasioned by the completion of a railroad through the camp in 1925.
Date: 1935
Creator: Schrader, Frank C.
Partner: UNT Libraries Government Documents Department

Geology of the Tonsina District, Alaska

Description: From introduction: The purpose of this paper is to describe the geology and mineral resources of a part of the Copper River Basin between the Richardson Highway and the valley of the Klutina River, together with small areas east of the highway and west of the river. For convenience in reference this area is called the Tonsina district, as the Tonsina River and Tonsina Lake are conspicuous local geographic features, and the Tonsina Road House, on the highway at the crossing of the river, is one of the oldest and best-known settlements in the Copper River Basin.
Date: 1935
Creator: Moffit, Fred H.
Partner: UNT Libraries Government Documents Department

Geology of Big Horn County and the Crow Indian Reservation, Montana: with Special Reference to the Water, Coal, Oil and Gas Resources

Description: From introduction: This report contains information concerning the geology of Big Horn County and the Crow Indian Reservation and their resources in ground water, coal, oil, and gas. These facts were collected in the course of studies for about a dozen field projects, which ranged in character from reconnaissance studies of large areas to very detailed mapping of certain tracts to show the occurrence of oil and gas. Consequently, the information at hand, either as to the geology or the resources, is not equally complete and definite for all parts.
Date: 1935
Creator: Thom, W. T., Jr.; Hall, George Martin; Wegemann, Carroll H. & Moulton, G. F.
Partner: UNT Libraries Government Documents Department

Pre-Cambrian Rocks of the Lake Superior Region: A Review of Newly Discovered Geologic Features, with a Revised Geologic Map

Description: From abstract: Detailed knowledge of the geology of the pre-Cambrian rocks of the Lake Superior region has been greatly augmented since the publication of Monograph 52 by the United States Geological Survey in 1911. The authors have attempted in the present report to assemble as much of this new information as possible, and to give the reader a birdseye view of the geology as seen in the light of all studies made there up to the present time. Detailed descriptions are not presented, and the emphasis is placed upon the major problems of correlation. A revised map of the region, with cross sections, accompanies the report, bringing up to date a knowledge of the areal geology of the region, which otherwise could be gained only by consulting some 150 maps contained in almost as many separate local reports, many of which are unpublished.
Date: 1935
Creator: Leith, C. K.; Lund, Richard Jacob & Leith, Andrew
Partner: UNT Libraries Government Documents Department

The Willow Creek-Kashwitna District, Alaska

Description: From introduction: The district described in this report is a triangular area covering about 300 square miles in the southwestern part of the Talkeetna Mountains. The Kashwitna River forms the northern boundary, the Susitna Valley flats the western, and the Willow Creek gold district, which is in the extreme southwestern part of the Talkeetna Mountains, the southern. As the area examined is not a distinct geographic unit, its boundaries being arbitrarily chosen and set only by the limitation of time spent in the field, a description of its geography applies to practically the entire western and southern portions of the Talkeetna Mountains, of which it is a part.
Date: 1935
Creator: Capps, Stephen R. & Tuck, Ralph
Partner: UNT Libraries Government Documents Department

Experiments with suction-type wings

Description: The present report collects the investigations of the past years which, while not as yet intended for use in construction, show different possibilities for the building of a suction-type wing and at the same time present some basic explanations concerning the problem of suction. Experiments and results with a thick wing profile are detailed as well as boundary layer removal by suction and sink action. Experiments with flap profiles are also included.
Date: August 1, 1935
Creator: Schrenk, O
Partner: UNT Libraries Government Documents Department

Flight tests of a balanced split flap with particular reference to rapid operation

Description: The flight path of a small parasol monoplane equipped with a special type of balanced split flap was determined for a series of glides during which the time taken to deflect or retract the flap was varied from 1 to 15 seconds in order to study the effect of the time taken to complete a flap movement on the motion of an airplane between the start of a flap movement and the attainment of steady flight with the new flap setting. For flap movements accompanied by a change of lift characteristics, and consequently of velocity, there is an appreciable delay in obtaining a desired change in glide angle even though the flap is operated instantaneously. Immediate control of the glide path is obtained only when the speed is maintained during the flap movement. When the speed is changed, the deviation from the desired path during the transition increases in proportion to the rapidity with which the flap is moved so that, with a high-lift flap, abrupt retraction at speeds less than the minimum speed with the flap retracted may be dangerous if practiced close to the ground.
Date: December 1, 1935
Creator: Soule, H A
Partner: UNT Libraries Government Documents Department

The interdependence of profile drag and lift with Joukowski type and related airfoils

Description: On the basis of a systematic investigation of Gottingen wind-tunnel data on Joukowski type and related airfoils, it is shown in what manner the profile drag coefficient is dependent on the lift coefficient. The individual factors for the construction of the profile drag polars are given. They afford a more accurate calculation of the performance coefficients of airplane designs than otherwise attainable with the conventional assumption of constant drag coefficient.
Date: March 1, 1935
Creator: Muttray, H
Partner: UNT Libraries Government Documents Department

The initial torsional stiffness of shells with interior webs

Description: A method of calculating the stresses and torsional stiffness of thin shells with interior webs is summarized. Comparisons between experimental and calculated results are given for 3 duralumin beams, 5 stainless steel beams and 2 duralumin wings. It is concluded that if the theoretical stiffness is multiplied by a correction factor of 0.9, experimental values may be expected to check calculated values within about 10 percent.
Date: September 1, 1935
Creator: Kuhn, Paul
Partner: UNT Libraries Government Documents Department

The influence of tip shape on the wing load distribution as determined by flight tests

Description: Pressure measurements were made in flight on the right upper wing of an M-3 airplane. The effects of tip plan form, washout, and transverse camber were investigated with eight tip forms in unyawed conditions through the range of positive lift coefficients from zero lift to the stall. The conclusion is that the tip plan form does not influence the span distribution of the coefficients of normal force and moment. It is shown inferentially that temperature, humidity, and the aging of the wood and fabric wing structure used on the M-3 airplane have an appreciable influence on the load distribution.
Date: January 1, 1935
Creator: Rhode, Richard V
Partner: UNT Libraries Government Documents Department

Infrared radiation from explosions in a spark-ignition engine

Description: This report presents the results of an investigation to determine the variations in intensity and spectral distribution of the radiant energy emitted by the flames during normal and knocking explosions in an engine. Radiation extending into the infrared was transmitted by a window of fluorite, placed either near the spark plug or over the detonation zone at opposite ends of the combustion chamber. Concave, surface-silvered mirrors focused the beam, first at the slit of a stroboscope which opened for about 2 degrees of crank angle at any desired point in the engine cycle, and then upon the target of a sensitive thermocouple for measuring radiation intensity. Spectral distribution of the radiant energy was determined by placing over the window, one at a time, a series of five filters selected with a view to identifying, as far as possible without the use of a spectrograph, the characteristic emissions of water vapor, carbon dioxide, and incandescent carbon.
Date: January 1, 1935
Creator: Marvin, Charles F , Jr; Caldwell, Frank R & Steele, Sydney
Partner: UNT Libraries Government Documents Department

Method for the determination of the spanwise lift distribution

Description: The method for determination of the spanwise lift distribution is based on the Fourier series for the representation of the lift distribution. The lift distribution, as well as the angle of attack, is split up in four elementary distributions. The insertion of the angle-of-attack distribution in the Fourier series for the lift distribution gives a compound third series which is of particular advantage for the determination of the lift distribution. The method is illustrated in an example and supplemented by a graphical method. Lastly, the results of several comparative calculations with other methods are reported.
Date: October 1, 1935
Creator: Lippisch, A
Partner: UNT Libraries Government Documents Department

A preliminary determination of normal accelerations on racing airplanes

Description: Rules and methods for insuring safe structural strength of racing airplanes used in the major air meets in this country have recently been considered. Acceleration records made in racing airplanes during actual air races were therefore considered desirable, and the NACA undertook the measurement of acceleration of loads on airplanes during all conditions of flight. Accelerations were measured on four airplanes at the Miami All-American Races in January 1934 and January 1935. The airplanes were representative of the fastest limited and unlimited displacement racing airplanes in current use in this country. Records during two races, or flights, on the race course were obtained with each airplane. The maximum normal acceleration recorded was 6.2g and the minimum was -1.2g.
Date: August 1, 1935
Creator: Scudder, N F & Kirschbaum, H W
Partner: UNT Libraries Government Documents Department

Full-scale force and pressure-distribution tests on a tapered U.S.A. 45 airfoil

Description: This report presents the results of force and pressure-distribution tests on a 2:1 tapered USA 45 airfoil as determined in the full-scale wind tunnel. The airfoil has a constant-chord center section and rounded tips and is tapered in thickness from 18 percent at the root to 9 percent at the tip. Force tests were made throughout a Reynolds Number range of approximately 2,000,000 to 8,000,000 providing data on the scale effect in addition to the conventional characteristics. Pressure-distribution data were obtained from tests at a Reynolds Number of approximately 4,000,000. The aerodynamic characteristics given by the usual dimensionless coefficients are presented graphically.
Date: March 1935
Creator: Parsons, John F.
Partner: UNT Libraries Government Documents Department

The heat transfer of cooling fins on moving air

Description: The present report is a comparison of the experimentally defined temperature and heat output of cooling fins in the air stream with theory. The agreement is close on the basis of a mean coefficient of heat transfer with respect to the total surface. A relationship is established between the mean coefficient of heat transfer, the dimensions of the fin arrangement, and the air velocity.
Date: January 1, 1935
Creator: Doetsch, Hans
Partner: UNT Libraries Government Documents Department

The effect of depth of step on the water performance of a flying-boat hull model

Description: NACA model 11-C was tested with four different depths of step to obtain information as to the effect of the depth of step on the water performance. The depths of step were selected to cover the practicable range of depths and in each case the included angle between the forebody and afterbody keels was kept the same 6-1/2 degrees. Small depths of step were found to give lower resistance at speeds below and at the hump speed of the model and greater depths of step lower resistance at high speeds. For low resistance throughout the speed range of the model investigated the most desirable depth of step is from 2.5 to 4.0 percent of the beam. The change of the best trim angle caused by variation of the depth of step was not appreciable. Increased depth of step caused increases in the maximum positive trimming moments at all trim angles investigated.
Date: July 1, 1935
Creator: Bell, Joe W
Partner: UNT Libraries Government Documents Department

Drag of prestone and oil radiators on the YO-31A airplane

Description: At the request of the Army Air Corps tests were conducted on a mock-up of the YO-31A airplane to determine the drag of the prestone and oil radiators. The drag of the airplane was determined with both radiators exposed on the lower surface of the fuselage; with each radiator exposed; and with no radiators. The results show that at 120 m.p.h the oil radiator accounted for 2.8 percent of the drag of the complete airplane; the prestone radiator 8.3 percent; and both radiators together, 11.8 percent.
Date: December 1, 1935
Creator: Defrance, S J
Partner: UNT Libraries Government Documents Department

The drag of airplane wheels, wheel fairings, and landing gears - I

Description: This report presents the results of tests made in the 7-by 10-foot wind tunnel and in the 20-foot tunnel of the National Advisory Committee for Aeronautics to determine the drag of a number of airplane wheels, wheel fairings, and landing gears designed or selected for an airplane of 3,000 pounds gross weight. All tests were made on full-size models; those in the 7-by 10-foot tunnel were made at air speeds up to 80 miles per hour and those in the 20-foot tunnel were made at air speeds up to 100 miles per hour. Although most of the landing-gear tests were made in conjunction with a fuselage and at 0 degree pitch angle, some of the tests were made in conjunction with fuselage plus wings and a radial air-cooled engine and at pitch angles from -5 degrees to 6 degrees to obtain an indication of the general effect of these various items on landing-gear drag. All tests were made in the absence of propeller slipstream.
Date: January 1, 1935
Creator: Herrnstein, William H & Biermann, David
Partner: UNT Libraries Government Documents Department

Effect of moderate air flow on the distribution of fuel sprays after injection cut-0ff

Description: High-speed motion pictures were taken of fuel sprays with the NACA spray-photographic apparatus to study the distribution of the liquid fuel from the instant of injection cut-off until about 0.05 second later. The fuel was injected into a glass-walled chamber in which the air density was varied from 1 to 13 times atmospheric air density (0.0765 to 0.99 pound per cubic foot) and in which the air was at room temperature. The air in the chamber was set in motion by means of a fan, and was directed counter to the spray at velocities up to 27 feet per second. The injection pressure was varied from 2,000 to 6,000 pounds per square inch. A 0.20-inch single-orifice nozzle, an 0.008-inch single-orifice nozzle, a multiorifice nozzle, and an impinging-jets nozzle were used. The best distribution was obtained by the use of air and a high-dispersion nozzle.
Date: January 1, 1935
Creator: Rothrock, A. M. & Spencer, R. C.
Partner: UNT Libraries Government Documents Department

Aircraft compass characteristics

Description: From Summary: "A description of the test methods used at the National Bureau of Standards for determining the characteristics of aircraft compasses is given. The methods described are particularly applicable to compasses in which mineral oil is used as the damping liquid. Data on the viscosity and density of certain mineral oils used in United States Navy aircraft compasses are presented. Results of flight tests are presented."
Date: December 14, 1935
Creator: Peterson, John B. & Smith, Clyde W.
Partner: UNT Libraries Government Documents Department

Comparative tests of Pitot-static tubes

Description: Comparative tests were made on seven conventional Pitot-static tubes to determine their static, dynamic, and resultant errors. The effect of varying the dynamic opening, static opening, wall thickness, and inner-tube diameter was investigated. Pressure-distribution measurements showing stem and tip effects were also made. A tentative design for a standard Pitot-static tube for use in measuring air velocity is submitted.
Date: November 1, 1935
Creator: Merriam, Kenneth G & Spaulding, Ellis R
Partner: UNT Libraries Government Documents Department

Combustion in a bomb with a fuel-injection system

Description: Fuel injected into a spherical bomb filled with air at a desired density and temperature could be ignited with a spark a few thousandths of a second after injection, an interval comparable with the ignition lag in fuel-injection engines. The effect of several variables on the extent and rate of combustion was investigated: time intervals between injection and ignition of fuel of 0.003 to 0.06 second and one of 5 minutes; initial air temperatures of 100 degrees C. to 250 degrees C.; initial air densities equivalent to 5, 10, and 15 absolute atmospheres pressure at 100 degrees C.; and air-fuel ratios of 5 to 25.
Date: January 1, 1935
Creator: Cohn, Mildred & Spencer, Robert C
Partner: UNT Libraries Government Documents Department

Aerodynamic characteristics of several airfoils of low aspect ratio

Description: From Summary: "This paper presents the results of wind-tunnel tests of several airfoils of low aspect ratio. The airfoils included three circular Clark Y airfoils with different amounts of dihedral, two Clark Y airfoils with slots in their portions, and three flat-plate airfoils. Lift, drag, and pitching-moment characteristics of the slotted airfoils with slots open and closed; pitching moment characteristics of one of the slotted airfoils with slots open and closed; and lift characteristics of the flat-plate airfoils are included. The results reveal a definite improvement of lift, drag, and pitching-moment characteristics with increase in dihedral of the circular Clark Y wing. Lift characteristics near the stall were found to depend markedly on the shape of the extreme tip but were not greatly affected by slots through the after portion of the airfoils. Changes in plan form of the flat-plate airfoils gave erroneous indications of the effect to be expected from changes in plan form of an airfoil of Clark Y section. The minimum drag characteristics of the circular Clark Y airfoils were found to be substantially the same as for a Clark Y airfoil of conventional aspect ratio."
Date: August 1935
Creator: Zimmerman, C H
Partner: UNT Libraries Government Documents Department