From page 1: The purpose of this circular is to show the degree of dependence of the United States upon foreign sources for the manganese required by its industries.

List of reduction mills in Montana, compiled in the course of investigations of mineral resources of Montana. It includes information about each loaction including: the process, character of ore, when the mill was operated, and custom work; equipment and power used; and capacity in tons.

Report on the need for regulations and inspections to counter preventable mine roof collapses and resulting injuries and fatalities.

Report describing information that should be provided for miners when they are first being trained on-site, as well as an explanation about the education program offered by the Practical Mining School at Dawson, New Mexico.

Brief summary of the geographic distribution, habits, history, and subgenera of Synaptomys.

Fourth edition of the United States Electrical Safety Code.

This is an all metal aircraft, including the wing coverings. Both the framework and the sheet-metal coverings are Alferium, made by Schneider Co. A description of the wing, fuselage, landing gear, engines, fuel tanks, characteristics, drawings, and photographs are provided.

The Amiot 120 B 3 is designed as a French combat aircraft. It can accept a variety of engines, and is equipped with 2 machine guns as well as specialized bomb sights and other combat equipment.

This is a light single-seat pursuit airplane with a tractor propeller actuated by a 12 cylinder V-type Hispano-Suiza engine giving 400 HP at 2000 R.P.M. This is a single winged aircraft capable of 273 km/h.

Report presenting a description of the Lioré-Olivier LeO 194 seaplane and a particular series of flights made over several months. Its fuselage is made entirely of wood. It has 6 gasoline tanks each with a capacity of 255 liters. It is a single engine biplane with wings mounted above the body of the seaplane.

This is a multi-engine monoplane with a central hull and without external bracing. The trim of the seaplane on the water is assured by two wing floats, one on each side of the hull 9 m. from its axis. It has a total power of 2100 HP. from 5 air cooled Jupiter radial engines.

Circular presenting a description of the Vojenska-Smolik all-metal two-seater airplane. The design and flight characteristics are described and blueprints and photographs of the aircraft are provided.

The Boeing Mail Airplane is a biplane with cloth covered wings of wood and wire construction, a top speed of 130 MPH, and a fuel capacity of 100 gallons in two tanks.

The 5000 is a semicantilever monoplane, closed cabin type, with pilot about in line with the leading edge of the wing and room for 4 passengers behind him. It is equipped with a Wright Whirlwind engine. A description of the visibility, propeller, power plant, pilot's cockpit, passenger cabin, landing gear, struts, wings, fuselage, empennage, general, characteristics, photographs, and drawings are provided.

The Caproni 73 is a biplane with medium thick wings, a rigid central section, and with each lateral extension forming a single cell and is powered by two 500 Isotta Fraschini "Asso" Engines.

The Fiat C.R. 20 has an all metal frame covered with fireproof fabric, except for the area near the engines, which is covered in duraluminum. It is armed with 4 machine guns and is capable of 280 KPH.

Designed by Engineer Brunet, the 3C2 is an all metal monoplane with two engines and provision for six machine guns and 12 10 Kg. bombs. A description of the design, components, characteristics, flying qualities, drawings, and photographs are provided.

Circular describing the Avro Gosport 504 R, which is a new training airplane that is lighter than other Avro training airplanes but is strong enough to withstand rough handling that may be encountered in training. Details of the fuselage, construction, ailerons, tail, struts, landing gear, fuel tanks, performance, characteristics, and photographs are provided.

Circular detailing the Glouster "Gambet", which is a new single-seat fighter for use from aircraft carriers. A description of the design, components, characteristics, photographs, and drawings are provided.

Societe Provencale de Constructions Aeronautiques, builder of the "Meteore 63" has constructed a three engine (biplane) seaplane which has met conditions for a seaworthy certificate of the first class. A description of the design, hull, tail, power plant, characteristics, performances, drawings, and photographs are provided.

Circular describing the Levasseur 8, which is an adaptation of a naval airplane adopted by the French Navy. Details of the wings, fuselage, landing gear, fuel, engine, and flying qualities are provided.

The Fairchild "all-purpose" is a 4 seater with a large luggage compartment, good visibility, and can be configured for surveying work. It is rated at 200 HP. at 1800 R.P.M., but can deliver over 220 HP.

The D.B. 10 is manufactured of duraluminum and special high resistance steel. It can be used as a passenger aircraft or as a bomber. Details of the design, wings, fuselage, empennage, engines, landing gear, characteristics, performances, drawings, and photographs are provided.

The Bluebird is a two seat, side by side biplane, designed primarily for training and pleasure flying. A description of the construction and flight characteristics is provided.