A nun prays on St Peter's square on the second day of the conclave on March 13, 2013 at the Vatican. Cardinals prepared for a second day of conclave behind the Vatican's walls to elect a pope today, with all eyes on a chimney that will signal when there is a new leader for the world's 1.2 billion Catholics. The 115 cardinals held a first inconclusive vote in the Sistine Chapel on Tuesday as they began the process of finding a successor to Benedict XVI, who brought a troubled eight-year papacy to an abrupt end by resigning last month. AFP PHOTO / GABRIEL BOUYS