Firefighters on Saturday installed the top of the Sistine Chapel chimney that will signal to the world that a new pope has been elected, as the Vatican took measures to definitively end Benedict XVI's pontificate. For such an important decision, the Sistine chimney is an awfully simple affair: a century-old cast iron stove where the voting ballot papers are burned, with a copper pipe out the top that snakes up the Sistine's frescoed walls, out the window and onto the chapel roof.

After years of confusion about whether the smoke was black or white, the Vatican in 2005 installed an auxiliary stove where fumigating cases are lit. The smoke from those cases — black or white — joins the burned ballot smoke out the chimney.

While construction workers prepared the interior of the frescoed Sistine Chapel for Tuesday's start of the conclave, officials elsewhere in the Apostolic Palace destroyed Benedict's fisherman's ring and the personal seals and stamps for official papers.