|Workers and a firefighter, at right, install the chimney, at left, on the roof of the Sistine Chapel|
As tradition dictates, the cardinals will use smoke signals to indicate whether a decision has been reached. The chimney will billow white smoke if they are successful - black smoke if they don't agree.
The smoke is produced by treating the cardinals' ballots with special color-producing chemicals and burning them.
Beginning Monday, 115 cardinals will go into seclusion, hold four votes each day and remain in the Vatican Palace until they have elected a successor to Pope John Paul II.
Some information for this report provided by AFP and AP.