Evening Republican, Volume 20, Number 164, Rensselaer, Jasper County, 11 July 1916 — Facts Concerning Sound. [ARTICLE]

Facts Concerning Sound.

Tn determining the transmission, reflection and absorption of sound by various materials, F. R. Watson has placed a whistle emitting a given note in the focus of a parabolic reflector, and in an adjoining room has stationed a Rayleigh resonator 0 -to receive the sound. The materials to be tested closed the doorway between the rooms. In the tests made, pressed fiber onefourth inch thick stopped practicmljf all sound; one-fourth inch cork boaro, 80 per cent and three thicknesses of this, 92.6 per cent. The transmission of sound at .constant pitch depends on the porosity, density and elasticity of the material; porous bodies transmitting sound about as they transmit air.