Object, Instrument, Technology

A tonometer consists of a series of steel cylinders that resonate at specific frequencies upon being struck with a metal hammer. They are used as standards for high frequencies, in the same manner as tuning forks. The transverse vibrational frequencies (i.e. fundamental and harmonics) of a given cylinder depend on the length, elastic modulus, and linear density of the metal.

Object, Instrument, Technology

Invented by John Shore in 1711, the tuning fork was initially used by musicians. After Chladni’s studies of its vibrations, however, it was also extensively employed by acousticians, who praised the purity of its sound. Hermann von Helmholtz, especially, based his experiments with beats, combination tones, and simple tones on tuning forks attached to resonators that enhanced their suitability for experimentation.

Text
Armstrong Cork,. 1932. “Armstrong's Acoustical Products”. Corkoustic, Ceramacoustic For Acoustical Correction Of Churches, Auditoriums, And Theatres, And Noise-Quieting Of Banks, Schools, Hospitals, Offices, Sunday School Rooms, Factories, And Other Public Buildings. Lancaster, PA.