Penn State models Liberty Bell sound for 250th anniversary

Researchers at Penn State University have modeled the acoustic properties of the Liberty Bell to determine what it sounded like before it stopped ringing. The study, conducted in honor of the nation's 250th anniversary, relies on data collected from one of the bell's replicas. The findings were first presented at a meeting of the Acoustical Society of America in Philadelphia earlier this year and subsequently published in Physics Today.

The Liberty Bell has not been rung in 180 years due to a famous crack. Historians remain uncertain about the exact date the crack formed, placing it sometime between 1817 and 1846. An 1846 account in the Public Ledger described a ringing on February 23 that year, noting that the bell had developed a crack which someone attempted to fix by filing the sides down. That effort failed, as the ringing extended the crack further, leaving the bell irreparably cracked and forever dumb.

This was not the first instance of structural failure for the bell. The rim cracked shortly after it arrived in Philadelphia in 1752, during the very first test strike by the clapper. Two local foundry workers, John Pass and John Stow, recast the bell twice because the first attempt produced a sound that one bystander likened to coal scuttles banging together.