To summarize, the experiments with balloons, sailplanes and light airplanes conducted thus far, reveal the vertical velocities of the air to be primarily dependent on the vertical temperature distribution. Stable stratifications result in up-and-down currents forced by the contour of the ground, which are readily recognized in flight and, if need be, may be avoided.

This report examines various aspects of seaplane construction; namely, stability, propulsion, water-tight bulkheads, fire protection, and construction.

A process for the measurement of the visibility of airplanes from the pilot's cockpit is developed. The apparatus necessary for the measurements was suitably constructed and measurements of the fields of vision were made with it. The visibilities of six airplanes of different types of construction and use were measured, as well as the visibility of an automobile for comparison. An attempt was made to establish minimum visibility requirements and to express the excellence of visibility by means of a numerical coefficient.

Equations are presented for two and three dimensional strut systems along with tables of equations.