I. REFLECTION OF SOUND ENERGY AND THICKNESS OF PLATE REFLECTOR—ULTRASONIC METHOD

Abstract

The work is an amplification of the method introduced previously by Boyle and Lehmann, and illustrates the application of the theory of monochromatic interference spectroscopy of optics to sound. By experiments with lead, duralumin and paraffin, at different high frequencies, the effects of both high and low reflecting powers are shown, and also the possible influences of harmonics. It is also shown that in travelling through thin discs the velocity of the waves is given more accurately by the bulk modulus of elasticity than by Young's.