ROME, Italy - ROME (CNN) -- Preparations, both spiritual and practical, neared completion at the Vatican on Monday, where Roman Catholic cardinals will gather to begin the process of selecting the next pope.
The conclave -- the secret papal election -- begins Tuesday in the Sistine Chapel, which has been closed to the public while Vatican staff readied the ornately decorated vestry for deliberations.
In addition, red curtains have been hung from the central balcony at St. Peter's Basilica -- the place where the new pope will be announced and then appear when he is elected. They will remain there until the announcement, the Vatican said Monday.
The first public signs of preparations appeared over the weekend as workmen scaled the roof of the chapel on Saturday to install the chimney which will release the black or white smoke that signifies whether a new pope has been elected.
Video released by the Vatican over the weekend showed the installation of a pair of stoves inside the chapel. One is used to burn the cardinals' ballots after they are cast and the other to send up the smoke signal -- the one that alerts the world that a vote has been taken and whether there's a new pope.
Black smoke signifies that no one has won yet. White smoke means a new pope has been chosen.
The decision will be made by cardinal-electors -- the 115 cardinals of the church under the age of 80, who arrived in Vatican City from all across the world.
Cardinals -- regardless of age -- have been meeting in daily sessions for the last week called General Congregations. More than 130 have spoken.
The final General Congregation will take place Monday.
The run-up to the conclave has taken a very spiritual tone.
"We cardinals sure are praying a lot," said Cardinal Timothy Dolan of New York, one of about a dozen leading candidates to become pope, who wrote in a blog post Friday.
Contrary to media reports, he said, the focus of the cardinals' meetings is much the same as it was two millenia ago, namely: "How most effectively to present the Person, message, and invitation of Jesus to a world that, while searching for salvation and eternal truth, are also at times doubting, skeptical, too busy, or frustrated."
This means discussions on such subjects as preaching, teaching the faith, care of the poor and sick, and support for the church's clergy and the families that make up their congregations, Dolan said.
"Those are the 'big issues.' You may find that hard to believe, since the 'word on the street' is that all we talk about is corruption in the Vatican, sexual abuse, money. Do these topics come up? Yes! Do they dominate? No!" he wrote.
Starting Tuesday, the cardinal-electors will move into a Vatican hotel, Casa Santa Marta, and will not be allowed to speak to anyone outside the conclave. They will attend a special morning Mass in St. Peter's Basilica.
The cardinals will cast their first vote Tuesday afternoon, with subsequent votes taken over the following days until one of the contenders gains a two-thirds majority. Once that happens, it means he is elected head of the world's 1.2 billion Catholics.
The longest conclave held since the turn of the 20th century lasted five days.
Meanwhile, the Italian press is full of speculation about which cardinal may win enough support from his counterparts to be elected, and what regional alliances are being formed.
The United States has 11 of the 115 votes, making it the second largest national bloc after Italy.
Sixty of the cardinals are from Europe and 67 were appointed by Benedict XVI, who stepped down at the end of last month, becoming the first pontiff to do so in six centuries.