Report presenting an investigation made of the flow downstream from a two-dimensional grid, formed of parallel rods. The two-dimensional character of the flow was insured by end plates normal to the rods and covering the entire flow field. The nature of the flow was determined primarily by means of total-head measurements.

Report presenting the utilization of the differential equation of Chaplygin's jet problem to give a systematic development of particular solutions of the hodograph flow equations, which extends the treatment of Chaplygin into the supersonic range and completes the set of particular solutions. The solutions serve to place on a reasonable basis the use of velocity correction formulas for the comparison of incompressible and compressible flows.

Built by the 'Czecho-Slovakian' aircraft factory, AVIA, the B.H. 21, has a top speed of 250 MPH, and carries 120 kg of gasoline and 20 kg of oil, giving it a radius of action of 600-650 km. It is equipped with a Hispano-Suiza engine capable of 300 HP. Details of the design, structure, wings, stabilizer, fuselage, controls, fuel tanks, landing gear, tail, characteristics, performances, drawings, and photographs are provided.

A product of the Air Navigation Engineering Co., the Missel Thrush is a light airplane suitable for private ownership. It is a two seat tractor fuselage biplane with single I interplane struts designed by J. Bewsher.

The 127 is a cantilever monoplane without external bracing. It is designed to accompany and protect bombardment and observation aircraft. Descriptions of the airfoil, fuselage, power plant, landing gears, and armament are provided.

Circular presenting a description of the Fairey "Battle", which is the first stressed-skin aircraft they have constructed and is also an all-metal low-wing cantilever monoplane. Details of the fuselage, wings, skin, design, flaps, landing gear, characteristics, performance, drawings, and photographs are provided.

The Goldfinch is equipped with the Bristol Jupiter Mark Vii engine. It is the all metal version of the Gloster Gamecock used by the R.A.F. A description of the construction, components, flying qualities, characteristics, drawings, and photographs are provided.

Circular describing the Guillemin J.G. 10, which is a two-place touring low-wing monoplane. Details of the wing, fuselage, engine, characteristics, drawings, and photographs are provided.

The Hamlet is a three engine high wing monoplane of comparatively small size, fitted with three Bristol Lucifer series IV engines of 130 HP. each, and designed to carry a pilot and four passengers. Details of the layout, wings, slot and flap gear, fuselage, characteristics, performance, and drawings are provided.

The Vega is a high wing monoplane suitable for commercial purposes. It can seat 6 passengers or 100 cubic feet of cargo. Various characteristics of the aircraft are described, including the wings, control surfaces, landing gear, and power plant.

Circular describing the Messerschmidt M.29 touring airplane, which is a two-seat cantilever monoplane that was specifically developed as a sport and touring airplane. Details of the flight characteristics, wing structure, fuselage, tail surfaces, landing gear, controls, power plant, instruments, miscellaneous details, characteristics, drawings, and photographs are provided.

Circular presenting a description of the Nieuport-Delage 590 three-engine colonial cantilever monoplane, which meets the requirements of the program established by the French Government. Information is provided regarding the design, construction, and instruments are provided.

The Mailwing is a single seat biplane designed primarily for mail and express delivery. It has a cargo capacity of 500 to 600 lbs. Details regarding the construction, engine, fuel tank, wings, tail, landing gear, propeller, control, characteristics, performance, drawings, and photographs are provided.

Circular describing the Saunders Cutty Sark commercial seaplane, which is a high-wing monoplane flying boat. Details regarding the power unit, engines, fuel system, components, characteristics, drawings, and photographs are provided.

Circular describing the Vickers Viastra I, which is a commercial high-wing all-metal semicantilever monoplane. Details of the structure, fuselage, wings, fuel tanks, landing gear, tail, cabin, cockpit, characteristics, drawings, and photographs are provided.

The Villiers 24 C.A.N. 2 is a night pursuit sesquiplane equipped with the 450 HP direct-drive Lorraine 12 Eb engine. It is characterized by Handley Page slotted wings. Details of the construction, wings, flaps, controls, characteristics, performances, drawings, and photographs are provided.