This report presents a discussion of how to determine the location of a line or surface from experimental data. What we desire to know practically is the number of ordinates required to obtain a certain probable precision in drawing a line or surface.

This report presents a description of an abacus with three scales: one for English measures, one for metric measures, and one with the "points of reduction", as well as construction details. There is also a detailed description on how to use the abacus.

Report presenting an examination of flexible piping and some of the difficulties involved in creating satisfactory flexible pipe. The joint used to assist in the flexibility of the pipe is illustrated and described.

Note presenting the physical properties which may be demanded of fuels for aviation use and the means that may be adopted by the engine manufacturers to properly meet the demands necessitated by the use of the fuel. Some of the factors that must be considered include its composition, the quantity available, the price per heat unit, and the possibility of keeping stocks in aerial ports both at home and abroad.

The Caproni Company recently built a seaplane of unusual design. The main supporting surfaces consisted of three triplanes in tandem, the lower wings being attached to the hull, which was described as providing accommodation for a hundred passengers. On one of the first flights, the seaplane fell into a lake, nose down, and was destroyed. The authors wish to show that this failure could have been predicted.

The need for a device to measure flight resistance, engine and propeller power, and efficiency during flight grew in proportion to the demand for increased flying capacity in military types of aircraft. Here, a dynamometer hub was inserted between the engine and the propeller. Taken as a whole, the tests that were conducted show that though the dynamometer is a sensitive instrument liable to numerous derangements, it is undeniably useful even in its present form, when handled with care and skill.

Report presenting the theory of the ideal propeller, which is important for solving the problem of the action of propellers. Several different theories of propeller action are described and compared to determine which ones seem to be the most accurate.