The chief purpose in undertaking the development of this synchronous motor was the creation of a very small, compact power source, capable of driving the film drums of the recording aircraft instruments designed by the staff of the National Advisory Committee for Aeronautics.

Note presenting an analysis of the propeller model tests of Dr. Schaffran. Only the thrust is examined. The results indicate that the thrust produced by three-blade and four-blade propellers follows the same laws as with two-blade propellers, and that all conclusions reached from Dr. Durand's tests can be upheld.

Discussed here is research on a spring activated fuel pump for solid or airless injection with small, high speed internal combustion engines. The pump characteristics under investigation were the interval of fuel injection in terms of degrees of crank travel and in absolute time, the lag between the time the injection pump plunger begins its stroke and the appearance of the jet at the orifice, and the manner in which the fuel spray builds up to a maximum when the fuel valve is opened, and then diminishes.