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Fuel-Briquetting Investigations, July, 1904, to July, 1912

Description: Report discussing a series of fuel-testing investigations that U.S. Geological Survey began in 1904 for the purpose of analyzing and testing the coals and lignites in the United States in order to determine their fuel values and the most efficient methods of utilizing them for different purposes. Types of tests undertaken included chemical analyses, steaming tests, gas-producer tests, briquetting tests, coking tests, and washing tests of samples collected from the various coals fields of the country. Bulletins presenting the results of these investigations have been periodically published but as supply has run out, the Bureau of Mines has decided to compile the most important facts of these bulletins in one volume along with the results of all other briquetting investigatins undertaken by the government from July 1, 1904, to July 1, 1912.
Date: September 1913
Creator: Wright, C. L.
open access

Metallurgical Coke

Description: Technical paper issued by the Bureau of Mines over studies on metallurgical coke. As stated in the introduction, "in this paper the attempt is made to summarize the history of coke making in the United States, to indicate the development of different methods and the modern types of ovens, and to point out the composition and physical properties of the metallurgical cokes produced in this country" (p. 5). This paper includes tables, illustrations, photographs, and a map.
Date: September 1913
Creator: Belden, A. W.
open access

A Review of the American Moles

Description: Discusses habits; economic status; characteristics and development of young; pelages and molts; and geographic, individual, sexual, and age variation. Describes subfamilies, history, and generic names of the family Talpidae. Describes, lists locations, and provides a key for genera, species and subspecies.
Date: September 30, 1915
Creator: Jackson, Hartley H. T.
open access

Drag or Negative Traction of Geared-Down Supporting Propellers in the Downward Vertical Glide of a Helicopter

Description: Discussed here are computations of drag or negative traction of geared down supporting propellers in the downward vertical glide of a helicopter. By means of Frounde's Theory, the maximum value of the drag of a windmill is calculated. For wooden propellers, the author finds that the difference between the drag and the weight is proportional to the number of blades and is larger for propellers of small diameter; thus it is 25 kg. for a six blade propeller with a diameter of 2 m. 50.
Date: September 1920
Creator: Toussaint, A.
open access

The Dynamometer Hub

Description: The construction of the dynamometer hub is illustrated and explained, and its electrical and aviation motor tests, as well as those in free flight, described.
Date: September 1920
Creator: Stieber, W.
open access

Experience With Geared Propeller Drives for Aviation Engines

Description: An overview is given of experience with geared propeller drives for aviation engines. The development of gear wheels is discussed with emphasis upon bending stresses, compressive stresses, heating, and precision in manufacturing. With respect to the general arrangement of gear drives for airplanes, some principal rules of mechanical engineering that apply with special force are noted.
Date: September 1920
Creator: Kutzbach, K.
open access

Recent Efforts and Experiments in the Construction of Aviation Engines

Description: It became evident during World War I that ever-increasing demands were being placed on the mean power of aircraft engines as a result of the increased on board equipment and the demands of aerial combat. The need was for increased climbing efficiency and climbing speed. The response to these demands has been in terms of lightweight construction and the adaptation of the aircraft engine to the requirements of its use.
Date: September 1920
Creator: Schwager, [Otto]
open access

The Effect of Staggering a Biplane

Description: This investigation was carried out by request of the United States Air Service at the Massachusetts Institute of Technology wind tunnel in 1918. As the data collected may be of general interest, they are published here by the National Advisory Committee for Aeronautics. The lift, drag, and center of pressure travel are determined for a biplane with a stagger varying from +100% to -100%. It is found that the efficiency and the maximum lift increase with positive stagger.
Date: September 1921
Creator: Norton, F. H.
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