Longitudinal elastic waves were produced in a truncated hollow aluminum cone with a wall thickness of 1/4 in. and an apex angle of 20 deg by the central impact of steel spheres ranging in diameter from 1/2 in to 1/16 in. This arrangement yielded transients whose dominant wavelengths varied by about a decade in the domain where geometrical dispersion was found to be critical. The input pulse at the truncated end was measured by means of piezoelectric crystals, while transmitted strains were observed by means of semiconductor gages on both the interior and exterior surfaces of the hollow cone. The results were compared with a corresponding one-dimensional analysis.