|Ernst Florens Friedrich Chladni
Born 1756 Died 1827
Born in Wittenburg in Germany, Chladni's Father demanded that he study Law not science. He obtained his law degree in 1782 from Leipzig. After the death of his Farther he vigorously pursued his career in science. Chladni achieved recognition for his pioneering work in the mathematical analysis of acoustics. This research was built on the early experiments of Robert Hooke at Oxford University. On July 8th 1680 Hooke formed the experiment of glass vibrating 6.4.8. places. This was done by putting flour on a glass plate, and bowing on the edge of glass. Hooke had observed that the motion of the glass was vibrate perpendicular to the surface of the glass, and that the circular figure of the flour changed into an oval one way, and the reciprocation of it changed it into an oval the other way. This phenomenon was rediscovered by Chladni in the eighteenth century, and given his name "Chladni figures". What Chladni did was to take thin metal plates and cover them with sand and caused them to vibrate. The sand collected in nodal lines producing symmetrical patterns similar to Hookes flour on the glass plate. It is also important to note that this influenced Faraday in thinking about lines of force in magnetic in his electrical experiments.
Chladni also produced two musical instruments the euphonium and the Clavicylinder. The Clavicylinder was a redesign of Hookes "musical cylinder" or string phone. In July 1664 Hooke produced and experiment to show the number of vibrations of an extended String, made in a determinate time, requested to give a certain Tone or Note, by which it was found that "a Wire making two hundred seventy two vibrations in one second of time sounded G Sol Re Vt. in the Scale of all Musick". Hooke had found that middle C had 272 beats a second, and on 1st September 1672 Hooke noted the he had invented an easy way for "a musical cylinder with pewter tips pinched between cylindrick rings".
Chladni was one of the firsts in the scientific community to state publicly that meteorites feel from the sky. He was ridiculed for this until Jean Baptist Biot confirmed it to be the correct in 1803. Its importance is that it influenced Faraday in thinking about lines of force in magnetic and electrical experiments.
Pg 101 Oxford Dictionary of Scientists- Oxford University Press- 1999
"An Early History of the Telephone 1664-1865"