"The mechanical and electrical construction of a new experimental instrument for fatigue testing riveted and welded joints is described. This experimental device has the advantage of being able to stress, even with comparatively low magnetic exciter force, structural components in alternate bending by resonance vibrations up to incipient fatigue failure (p .1)".

The results are presented of a triple series of tests using force measurements, pressure-distribution measurements, and air flow photographs on airfoil sections suitably selected so that comparison could be made between the experimental and theoretical results. The comparison with existing theory is followed by a discussion of the divergences found, and an attempt is made to find their explanation.

This report describes a testing machine on which 35 millimeter bearings (bore) can be run at speeds of the order of 21,000 rpm, while the following factors are recorded: 1) oil circulation through bearing and oil temperature. 2) maximum temperature of outer bearing ring, 3) radial and axial load on bearing, 4) radial, axial, and angular clearance of bearing, 5) power consumption of bearing. The experiments show that the lubrication was most reliable and oil consumption lowest when the oil was introduced through a hole in the outer or inner ring of the bearing.