From Summary: "This report presents a concise survey of the measurement of air speed and ground speed on board aircraft. Special attention is paid to the Pitot-static air-speed meter which is the standard in the United States for airplanes. A bibliography on air-speed measurement concludes the report."

Report includes the National Advisory Committee for Aeronautics letter of submittal to the President, Congressional report, summaries of the committee's activities and research accomplished, bibliographies, and financial report.

The purpose of the first two parts of this report is to present in concise format all the formulas required for computation of the hydrodynamic forces, so that they can be easily computed for either straight or curvilinear flight. Improved approximations are also introduced having a high degree of accuracy throughout the entire range of practical proportions. The remaining two parts of the report are devoted respectively to stability and skin friction, as functions of the same hydrodynamic forces.

Topographic map of a portion of Texas from the United States Geological Survey (USGS) project. The map includes towns, historic or notable sites, bodies of water, and other geologic features. Scale 1:31680

Topographic map of a portion of Texas from the United States Geological Survey (USGS) project. The map includes towns, historic or notable sites, bodies of water, and other geologic features. Scale 1:31680

From abstract: The largest single metal-mining operation in the history of mining in Colorado has been developed at Climax, as a result of the increased use of molybdenum in the steel and other industries. Production of molybdenum at Climax was notable for a short period during the World War; it ceased from April 1919 to August 1924 but since then has shown a steady increase. In 1930 from 1,000 to 1,200 tons of ore was milled daily, using only one unit of the 2,000-ton mill. The mine has a reserve of broken ore sufficient to furnish 2,000 tons daily for 3 years and is being developed to continue to furnish this and a still further increased output as the use of the metal may warrant.

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.

Circular presenting a description of the De Havilland Dragon Moth, or D.H. 84, which is the first twin-engine airplane built by this particular company. Details of the design, components, flight characteristics, performance, drawings, and photographs are provided.

This report describes a device for arbitrary enlargement of the gliding angle of airplanes, especially of such with flat gliding angle and difficult landing characteristics. The D.V.L. gliding angle control (design, Hubner) permits a local interruption of the lift distribution along the span and consequently an increased induced drag. The mechanism comprises two wing rudders operated by lever from the pilot's cockpit. Said rudders are fitted on the top side of the wing near the leading edge. The displacement of these rudders results in a separation of the air flow on the top side of the wing.

Revised edition. "This publication shows how to determine, by the size and condition of the teeth, the approximate age of cattle from calfhood to six years and older." -- p. ii

A guide to growing dewberries in various regions of the United States.

"The static stresses of airplane parts, the magnitude of which can be determined with the aid of static load assumptions, are mostly superposed by dynamic stresses, the magnitude of which has been but little explored. The object of the present investigation is to show how the strength of airplane parts can best be tested with respect to dynamic stresses with and without superposed static loading, and to what extent the dynamic strength of the parts depends on their structural design. Experimental apparatus and evaluation methods were developed and tried for the execution of vibration-strength tests with entire structural parts both with and without superposed static loading" (p. 1).

Volume provides abstracts of agricultural experiments conducted during the year. Also includes statistics, convention reports, bulletins, bibliographies, and listings for Spanish edition publications from the Porto Rico Station. Name and subject indexes start on page 785.

Volume provides abstracts of agricultural experiments conducted during the year. Also includes statistics, convention reports, bulletins, bibliographies, and listings for Spanish edition publications from the Puerto Rico Station. Name and subject indexes start on page 877.

From Introduction and Summary: "The first of these was Bulletin 353, dealing with the tests of rock-dust barriers; the second is the present paper, which reports tests made to determine the effect on the explosibility of Pittsburgh coal dust of altering conditions under which the tests were made; the third, dealing with tests of dust prepared from approximately 20 coals taken from beds in mines in different parts of the United States, will follow after the completion of testing in progress at the time of writing."

Topographic map of a portion of Texas from the United States Geological Survey (USGS) project. The map includes towns, historic or notable sites, bodies of water, and other geologic features. Scale 1:31680

Topographic map of a portion of Texas from the United States Geological Survey (USGS) project. The map includes towns, historic or notable sites, bodies of water, and other geologic features. Scale 1:31680

From Abstract: Two areas and their included mineral deposits, situated in Josephine County, southwestern Oregon, are described in this report. They lie within the Klamath Mountains, a region which is made up for the most part of rugged ridges trending in various directions but which, when viewed from higher summits, resembles a dissected plateau and is known as the Klamath peneplain. Rocks of both igneous and sedimentary origin are abundant in the districts described. The marine sedimentary rocks of the areas comprise a thick series of Carboniferous strata, with some interbedded volcanic rocks, and portions of the Galice formation, of Jurassic age, and of an Upper Cretaceous formation. The rocks of fluviatile origin include Tertiary conglomerate, Pleistocene valley fill, termed the " Llano de Oro formation," and somewhat later Pleistocene gravel and alluvium, in part glacial debris. Recent gravel is found along the present streams. The igneous rocks include several varieties of greenstone of probable Paleozoic and Mesozoic age and serpentine of late Jurassic or early Cretaceous age.

From introduction: This report embodies the results of investigations of three gold mining districts in Josephine and Curry Counties, southwestern Oregon.

From abstract: The Girdwood district has been known for about 35 years to contain placer gold, but the source of the gold in veins was not discovered until about 1909. When the Alaska Railroad was completed through Girdwood it was hoped that the improved transportation facilities would enable the lode mines to operate at a profit and also to furnish tonnage to the railroad. Production from the quartz veins, however, has been negligible, although one placer mine has been operating steadily for several years.

Topographic map of a portion of Texas from the United States Geological Survey (USGS) project. The map includes towns, historic or notable sites, bodies of water, and other geologic features. Scale 1:48000

Topographic map of a portion of Texas from the United States Geological Survey (USGS) project. The map includes towns, historic or notable sites, bodies of water, and other geologic features. Scale 1:31680

Revised edition. Report discussing methods and places for collecting and storing ice on farms. Discussion focuses on construction and preparation of ice houses.

Revised edition. Report discussing lice and mange, two external parasites which commonly affect hogs. Infected hogs may experience irritation, arrested growth, lack of vitality, and have an increased risk of death. Both diseases are discussed in details along with potential remedies. Treatments include hand applications, spraying, hog oilers, medicated hog wallows, and dipping.