... No one recorded when or why the
Liberty Bell first cracked, but the most likely explanation is that a
narrow split developed in the early 1840s after nearly 90 years of hard
use. In 1846, when the city decided to repair the bell prior to George
Washington's birthday holiday (February 23), metal workers widened the
thin crack to prevent its farther spread and restore the tone of the
bell using a technique called "stop drilling". The wide "crack" in the
Liberty Bell is actually the repair job! Look carefully and you'll see
over 40 drill bit marks in that wide "crack". But, the repair was not
successful. The Public Ledger newspaper reported that the repair failed
when another fissure developed. This second crack, running from the
abbreviation for "Philadelphia" up through the word "Liberty", silenced
the bell forever. No one living today has heard the bell ring freely
with its clapper, but computer modeling provides some clues into the sound of the Liberty Bell. ...
