Memorandum presenting the rules and regulations of the Endurance Contest of Aviation Engines, which was put on by the Aero Club of France. A description of the rules regarding the aircraft in competition, the characteristics of the tests that were conducted, and information regarding classification of the aircraft is provided.

Static soaring flight has hitherto been accomplished by means of two sources of energy: ascending air currents in the vicinity of obstacles and those produced by unequal heating. The latter has not yet been practically tested in soaring flight.

Memorandum presenting a method of calculating the dead reckoning in aerial navigation.

Different aspects of an airship line between Lisbon and Rio de Janeiro are presented. Some of the factors discussed are: the number of passengers, fuel consumption, design, itinerary, airports, flight times, and income.

Memorandum presenting the history and development of airships. Tables containing information and statistics regarding some of the current airships are provided.

This article presents a discussion of the relative merits between monoplanes and biplanes. A comparison of the aerodynamic qualities and advantages of both types are provided.

"The vertical distribution of the pressure, temperature, and density of the atmosphere varies from day to day. Thus, rates of climb on different days cannot be compared directly, but must be corrected with reference to a standard rate of diminution of air density with increasing altitude. The following problem, therefore, has to be solved" (p. 1).

In the first series of wind tunnel tests, the drag and cross wing force of all the struts were measured at a wind speed of 30 mph and at angles of yaw from 0 degrees to 20 degrees. To determine the magnitude of the VL effect, each strut was tested at zero yaw and at a series of speeds ranging from 15 to 38 mph. Although designed as fairings for cables, part of these sections gave such high crosswind forces that they seemed to have possibilities as airfoils.

"For the calculation of the parasite resistance of an airplane, a knowledge of the resistance of the individual structural and accessory parts is necessary. The most reliable basis for this is given by tests with actual airplane parts at airspeeds which occur in practice. The data given here relate to the landing gear of a Siemanms-Schuckert DI airplane; the landing gear of a 'Luftfahrzeug-Gesellschaft' airplane (type Roland Dlla); landing gear of a 'Flugzeugbau Friedrichshafen' G airplane; a machine gun, and the exhaust manifold of a 269 HP engine" (p. 1).

In making tension tests, the slippage of the joints was noted at three points across each joint. In addition, stress strain curves were obtained for plain tension specimens, and a chemical analysis was made of the sheet.