Report issued by the U.S. Bureau of Mines covering accidents that happened in metal mines located in the United States including statistics for injuries, fatalities, kinds and causes of accidents, and operational data, such as number of mine workers and shifts worked.

From Introduction: "In this report the author has presented data of actual gas-lift operations in the oil fields of California. Wherever theoretical hypotheses and conclusions are given an attempt has been made to support them by field data gathered during consultation with engineers and operators. The impossibility of drawing conclusions that will apply to all wells or even to one well throughout its life is appreciated by everyone who has studied the subject, and the reader is cautioned not to accept all the data presented as being applicable to every well."

From Introduction: "Because of the above reasons, because there is a dearth of published information relating to the effect of vacuum oil wells, and because misapplication of vacuum may result in a greatly decreased ultimate recovery of oil, whereas the correct application may have the opposite effect, the Bureau of Mines has authorized this investigation."

Report describing a chemical and thermodynamic overview of zinc smelting. The methods described are not new, but the analysis is deeper and more focused than in previous reports.

Introduction: "This bulletin discusses ventilation methods, practices, and costs at 11 large copper mines in Arizona, as obtained by brief personal studies and from supplementary information furnished by the mine managements. These mines were visited from December, 1928, to November, 1929, and the methods and practices in use when visited are described in some detail."

From Function of Methane Detectors: "The object of this paper is to present to the mining public the results of the permissibility tests of the detectors that have been approved, also to give the results of a series of tests conducted to determine their practicability."

From Introduction: "This paper gives a brief account of the introduction of electric lighting in mines, reviews some of the preliminary and approval work on electric mine lamps up to July, 1917, when a previous bulletin on electric lamps was issued, and describes the lamp-approval work from that date of July, 1930."

From Scope of Report: "The first part of this report deals with the principal methods of refining light petroleum products, the equipment used, and the effects of the different refining agents. The second part of the report deals with a study of the value of fractionation as an aid to the refining of pressure distillates."

From Introduction: "The presence in the Cripple Creek district, Colo., of irrespirable gas or gases, generally known to consist mainly of nitrogen and carbon dioxide, has been recognized by members of the mining industry in that region almost since underground mining was begun there; the occurrence origin, and possible control of these gases have been discussed in several articles cited at various places in this report. Similar gases have also been studied in other metal-mining districts, as later discussed."

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.

From Introduction: "The Bureau of Mines has attempted to develop a cheap and efficient solvent that would especially meet the requirements of smaller plants. (See Bibliography). A method of producing this solution from sulphurous products and waste liquors was developed by the bureau and tried successfully on a test-plant scale at the Southwest Experiment Station in cooperation with the department of mining and metallurgy, University of Arizona, Tuscon, Ariz."

From Introduction Results of Test: "Among the domestic potash resources which were brought to the attention of the country during and after the war but were not utilized as a source of potash, although they indicated that they might furnish the cheap potash desired, were the potash deposits occurring with the think rock-salt formations of western Texas and southeastern New Mexico."

Report discussing the loads and extracting of slime and other divided ores. The report discusses experimental work done on the materials.

From Introduction: "The references given herein to the literature of greensand or glauconite are believed to be complete up to about the end of 1929. The aim in this bibliography has been to include with each important reference a short synopsis, generally checked against the original article. These synopses are believed to be sufficiently complete to present a general view of the original article, and in many items specific parts of the article are included."

Report published by the U.S. Bureau of Mines which is a compilation of accidents in quarries located in the United States with data regarding the number and kinds of accidents as well as information about the mining operations (e.g., number of men employed, kinds of quarries, amount of work performed, etc.).

From Scope and Arrangement of Review: "This review is confined to the technical literature of the origin, history, and foreign occurrences of saline potassium minerals, their mining, description, treatment, and physical-chemical relations. The literature on alunite, jarosite, and related minerals has also been included. The literature on potash minerals associated with the nitrate deposits and on the silicate minerals has been omitted as well as that on analytical methods, statistics, political economy, and the very large field of patent literature. The material in this review is arranged chronologically and alphabetically according to the authors within each year."

Report discussing earthquake activity in the United States during 1928. The report is broken down by regions and has sections for specific earthquakes.

Report presenting information on the production of silver around the world.

"Tests on a Friez type cup anemometer have been made in the variable density wind tunnel of the Langley Memorial Aeronautical Laboratory to calibrate the instrument and to determine its suitability for velocity measurements of wind gusts. The instrument was calibrated against a Pitot-static tube placed directly above the anemometer at air densities corresponding to sea level, and to an altitude of approximately 6000 feet. Air-speed acceleration tests were made to determine the lag in the instrument reading. The calibration results indicate that there should be an altitude correction. It is concluded that the cup anemometer is too sluggish for velocity measurements of wind gusts" (p. 1).

A large number of tests were made on tubes of 1025 and 4130X steel, in various diameters and wall thicknesses, and after diverse heat treatments. The Rockwell B scale was employed, as being the best suited to the ranges of hardness encountered. Only satisfactory chrome molybdenum tubes were found to show a hardness in excess of 90-B after normalizing.

"This investigation was conducted to determine the effectiveness of various surface coatings as a means for preventing ice formations on aircraft in flight. The substances used as coatings for these tests are divided into two groups: compounds soluble in water, and those which are insoluble in water. It was found that certain soluble compounds were apparently effective in preventing the formation of ice on an airfoil model, while all insoluble compounds which were tested were found to be ineffective" (p. 1).

"The drag due to the various parts of a Fairchild (FC-2W2) cabin monoplane was measured at air speeds varying from 50 to 100 m.p.h., in the Twenty-Foot Propeller Research Tunnel of the National Advisory Committee for Aeronautics. It was found that the largest drag was due to the radial air-cooled engine. The measured drag due to the landing gear was also large, being about 4/5 of that due to the engine" (p. 1).

"This note describes tests of an adjustable blade metal model propeller, both in a free wind stream and in combination with a model fuselage, at four settings of the blades. The model propeller is designed for a uniform nominal pitch/diameter ratio of .7 and the blade settings used correspond to nominal pitch/diameter ratios of .5, .7, .9, and 1.1 at the .6 radius. The tests show that propellers of this type may be considerably changed in setting from the designed pitch angles and yet give excellent performance" (p. 1).

Discussed here are problems with the use of cowlings with radial air cooled engines. An XF7C-1 airplane, equipped with service cowling and with narrow ring, wide ring, and exhaust collector ring cowlings over the service cowling, was used. For these four cowling conditions, the rate of climb and high speed performance were determined, the cylinder conditions were measured, and pictures to show visibility were taken. The level flight performance obtained with an engine speed of 1900 r.p.m. for the service type, the narrow ring, the wide ring, and the exhaust collector ring was 144.4, 146.6, 152.8, and 155 mph, respectively.