The wide gap in the Liberty Bell isn't the crack that silenced it. It's a repair: in 1846, metalworkers drilled along a thin crack on purpose to stop it from spreading, a technique the National Park Service calls stop drilling. You can still see more than 40 drill marks along its edges (NPS: "over 40 drill bit marks are visible in the crack").

• ✓NPS, The Liberty Bell (nps.gov/inde/learn/historyculture/stories-libertybell.htm): stop drilling; "over 40 drill bit marks are visible in the crack"; second crack Feb 23, 1846
• ✓NPS Junior Ranger: stop drilling (home.nps.gov/inde/learn/kidsyouth/jrrangerchallenge-libertybell.htm)
• ✓FAA AC 43.13-1B, par. 3-23, 3-40, 4-91 (stop-drilling cracks)
• ✓en.wikipedia "Liberty Bell"
• ✓NASA image KSC-97PC-163 (1997), caption: workers drilling to stop a crack in the Mobile Launcher Platform

This gap in the Liberty Bell looks like the famous crack. It isn't. Look closer: it's lined with more than 40 drill marks. By 1846, a thin crack was spoiling the bell's sound. So metalworkers drilled along it on purpose, to stop it from spreading. It's called stop drilling. Engineers still use a version of it today: a hole drilled at the end of a crack, on aircraft, and even rocket launch platforms. But on the Liberty Bell, it failed. Within hours of ringing it for Washington's birthday, a new crack ran up from the repair. It has never been properly rung since, only gently tapped. So that gap isn't the crack. It's the fix, and the crack that beat it is this thin line through the word Liberty. Subscribe for a fact every day.