The first vote was held around 2:40 p.m. Boston time and black smoke emerged from the Sistine Chapel chimney at the Vatican, signalling no pope has been chosen yet.
Vatican officials say it is possible the cardinals may decide not to vote Tuesday, but if they do, it would be late in the day.
If Roman waiters and cab drivers are any indication, Cardinal Sean has the popular vote.
In the absence of information, there is rampant speculation. One Italian newspaper polled its writers — asking them to guess which Cardinals are now the leading candidates to become the next pope.