Acoustical experiments with a mechanical vibrator

In this Paper some preliminary experiments are described with a mechanical device vibrating a piston at one end of a tube so that a sound wave is emitted at the other. The particle velocities in the sound wave are measured by a Rayleigh disc, and resonance curves are drawn. It is shown how the energy in the sound wave can be calculated from the results obtained. The experiments are directed towards obtaining a standard source of sound, and the results are encouraging, but a considerable amount of work remains to be done.