Chimney installed on Sistine Chapel's roof ahead of conclave to pick Pope Francis' successor

The chimney that will let the world know when cardinals have chosen a successor to Pope Francis was installed Friday on the roof of the Sistine Chapel.  

Firefighters were seen putting up the fixture ahead of the conclave set to begin next Wednesday. 

During a conclave, cardinals vote through a secret ballot. A two-thirds majority is required for the election. After each round of submissions, ballots are read aloud and then burned. The ashes are used to notify audiences around the world and onlookers in St.