Cardinal Marc Ouellet of Canada waves as he arrives for a meeting at the Synod Hall in the Vatican March 6, 2013. REUTERS/Tony Gentile

ROME — Vatican officials were busy Saturday making final preparations for the conclave that will begin Tuesday to elect a new pope.

For the first time ever, a Canadian cardinal — Quebec's Marc Ouellet — is seen as one of the leading contenders to succeed Benedict XVI on the papal throne.

The world's most famous smokestack was installed Saturday morning here on top of the Sistine Chapel. Black smoke from that chimney, of course, after a round of balloting means no cardinal has received the two-thirds majority required to elect a new pope.

White smoke — along with the pealing of bells throughout St. Peter's Square — means a new pope has been selected to lead the world's billion and more Roman Catholics.