a. [f. prec. + -AL.] Of or pertaining to vibration; vibratory.
1878. Prescott, Sp. Telephone, 249. The number of vibrational forms which may arise from the composition of simple forms are mathematically infinite.
1884. H. R. Haweis, My Musical Life, iii. 86. The very appearance of the wood would guide him to its probable vibrational powers.
1888. Encycl. Brit., XXIV. 242. In order that the vibrational impulse may be given as nearly as possible at the centre of the mass of air in the resonant box.
b. Vibrational number (see quot. 1881).
1879. C. Parry, in Grove, Dict. Mus., I. 670. As far as the ratios of the vibrational numbers of the limiting sounds are concerned.
1881. Broadhouse, Mus. Acoustics, 48. We are accustomed to take a second of time as the unit, and consequently mean by vibrational number the number of vibrations which the particles of a sounding body perform in one second of time.
