Ernst Chladni (1756-1827) is regarded by many historians as the 'father of acoustics' for his seminal experimental work on vibrations. He was also a well respected musician and inventor of musical instruments.
Ernst Chladni (image 1) was born in Wittenberg, Germany. Chladni's father, who was a professor of law at the University of Wittenberg, disapproved of his son's early interests in music and science and forced him to study law. Chladni duly obtained a law degree from the University of Leipzig in 1782. In the same year, following the death of his father, Chladni found himself free to pursue his interests in music and science, which he did with remarkable success.
Chladni is best known for his work in acoustics, and for his invention of a method for visualizing the patterns of vibrations on mechanical surfaces. The Whipple has two examples of 'Chladni plates' - metal plates that can be caused to vibrate using a violin bow (image 2). Building on pioneering work done by Robert Hooke (1635-1703) in Oxford during the late 17th century, Chladni revealed the patterns of vibration using fine sand, which settles into the nodal lines (areas of zero displacement) producing striking and beautiful shapes. Chaldni's demonstrations attracted the interest of the French Emperor, and amateur scientist, Napoleon Bonaparte (1769-1821) who was so impressed that he financed the translation of Chaldni's major work Die Akustic into French, which appeared in 1809 (image 3).
Chladni also conducted some of the first research into tuning forks, paving the way for the perfection of these implements as musical and scientific instruments. This study was the technical groundwork for his best known musical instrument, the clavicylinder. This keyboard instrument worked using resonating metal bars, like tuning forks, which were pressed against a rotating felt-covered friction wheel. Chladni spent many years touring Europe giving performances of popular works by famous composers. The instrument enjoyed widespread acclaim, but unfortunately for Chladni it never caught on as a serious orchestral instrument, being outshone by Benjamin Franklin's (1706-1790) glass armonica.
Chladni is also notable for his pioneering work on meteorites. In 1794 he was the first to propose that meteorites have their origins in outer space - a claim which initially attracted ridicule. His opponents favored a theory connecting meteorites to volcanic activity, but he was later vindicated by the work of Jean Baptiste Biot (1774-1862) in 1803.
Torben Rees, 'Ernst Chladni: physicist, musician and musical instrument maker', Explore Whipple Collections, Whipple Museum of the History of Science, University of Cambridge, 2009 [http://www.hps.cam.ac.uk/whipple/explore/acoustics/ernstchladni/, accessed 06 October 2015]