In soaring flight, ascending air currents are utilized and the interesting question is raised whether there are such currents which extend to any considerable distance and which can be utilized practically.

Report presenting an investigation of problems related to helicopters. Also included are the history of the evolution of the helicopter and a series of propeller experiments.

The advantages of using seaplanes for commercial purposes is discussed. The three primary advantages described include their superior speeds over existing means of transport on the same routes, the available landing fields when flying over the water, and the reduction of distance from the airport to the city is serves due to the seaplane's ability to land in water.

The "L 58" is a monoplane with cantilever wings joined directly to the fuselage. It accordingly belongs to the new school of airplane construction, as founded and developed in Germany. A list of performance characteristics is included.

"For a first approximation the air flow around the airship hull is assumed to obey the laws of perfect (i.e. free from viscosity) incompressible fluid. The flow is further assumed to be free from vortices (or rotational motion of the fluid). These assumptions lead to very great simplifications of the formulae used but necessarily imply an imperfect picture of the actual conditions. The value of the results depends therefore upon the magnitude of the forces produced by the disturbances in the flow caused by viscosity with the consequent production of vortices in the fluid" (p. 1).

Note describing the variation in the number of revolutions per minute and provides simple formulas that allow for advanced calculation to be made of the variation of propeller speed with variation of one or more dimensions of the propeller and allow the necessary corrections to be applied.

Note presenting an investigation of the increase in the dimensions of airplanes, including the weight, area, and loading of wings, and how increasing the size of different components may affect these aerodynamic factors.

"Experiments with fuel mixtures of varying composition, have recently been conducted by the Motor Vehicle and Airplane Engine Testing Laboratories of the Royal Technical High School in Berlin and at Fort Hahneberg, as well as at numerous private engine works. The behavior of hydrogen during combustion in engines and its harmful effect under certain conditions, on the combustion in the engine cylinder are of general interest. Some of the results of these experiments are given here, in order to elucidate the main facts and explain much that is already a matter of experience with chauffeurs and pilots" (p. 1).

Report presenting suggestions for the standardization of the study of aerodynamics in laboratories in the United States and Europe. A report by each of the different scientists, all of whom are working in a variety of different labs and countries, is provided, and each discusses the progress made in their respective labs and their suggestions for standardization and progress in the field.

Describes the benefits of using motor trucks on farms in the Corn Belt, based on a survey of farmers in that region who own trucks. Discusses profitability, efficiency, and compares the use of trucks to the use of horses.

This bulletin is presented for the primary purpose of aiding the citrus industry in the Lower Rio Grande Valley and by a statement of authentic facts to apprise the public of the magnitude and possibilities of this rapidly developing industry.

Patent for improvements in sheet-placing machines for pushing and pulling devices to their correct orientation of oil tanks (lines 10-13) roof construction without the possibility of injury to mechanics.