Object, Instrument, Technology

These instruments demonstrate the “communication of vibrations” between connected plates. This was a topic first investigated by the French scientist Felix Savart, in the 1820s. Savart experimented with a pair of identical glass disks that were connected by only a single glass rod. When the two disks were sprinkled with sand and the first one vibrated, both disks formed identical patterns.

 

 

Source: Steven Turner; Curator, Physical Sciences, National Museum of American History, Smithsonian Institution. 

Picture: Steven Turner

Object, Instrument, Technology

This rack has 3 square and 3 circular brass plates of varying dimensions. It was used to demonstrate the effect of changes in the size and thickness of plates on both their tone and the Chladni figures that they produce. A plate that is the same size as the one next to it, but double the thickness, will produce a note twice as high, while a plate that is half the area of the one next to it, but double the thickness, will sound a note that is four times higher.

 

 

Text
Robartes, Francis. 1692. “A Discourse Concerning The Musical Notes Of The Trumpet, And Trumpet-Marine, And Of The Defects Of The Same”. Philosophical Transactions 16 (95): 559-563.
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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.
Text
Armstrong Cork,. n.d. “Armstrong's Vibracork For Lessening Transmission Of Vibration”.
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Koenig, Rudolph. 1864. “Beirag Zur “Theorie Der Klangfiguren Von Wheatstone””. Annalen Der Physik Und Chemie 122: 238-242.
Object, Instrument, Technology

Date of production: 1950s

Image
“Brüel & Kjær 2304 Level Recorder (1)”. n.d.
Image
“Brüel & Kjær 2304 Level Recorder (2)”. n.d.
Video
Braguinski, Nikita. 2018. Brüel & Kjær 2304 Level Recorder (Video).