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Inventions
2 Things in Inventions. Select a category or move through the pages.
Library of CongressThe phonautograph
Édouard-Léon Scott de Martinville built a machine that traced airborne sound. A voice recorded in 1860 remained silent until researchers converted its paper waveform into audio in 2008.
Luray CavernsThe Great Stalacpipe OrganInside Virginia’s Luray Caverns, an organ console controls rubber-tipped mallets that strike stalactites spread across the cave, turning natural stone formations into sounding bars.