The election of a new pope captivates audiences worldwide, not through press conferences or social media updates, but via the iconic smoke signals emitted from the chimney atop the Sistine Chapel. This centuries-old tradition signifies the outcome of the papal conclave: black smoke indicates no pope has been elected, while white smoke announces the new pontiff’s election with the words, “Habemus Papam”—we have a pope. This dramatic moment is broadcast live, drawing millions of viewers, yet the complexity behind this ritual remains largely unseen.
The engineering behind the tradition
Experts highlight the intricate preparations involved in this process, which includes the construction of a specialized chimney, the installation of engineered stoves, and the use of carefully formulated chemical mixtures. “It requires two custom fireworks, smoke test rehearsals, and Vatican firefighters on standby,” noted a specialist, emphasizing the collaborative effort by a team of engineers and Church officials to ensure that every wisp of smoke conveys a clear and unmistakable message.
Following the death of Pope Francis on Easter Monday at the age of 88, attention has turned to the upcoming conclave scheduled for May 7 at St. Peter’s Basilica. This gathering will commence with a special Mass before the cardinals assemble in the Sistine Chapel to begin the voting process. The tradition of burning ballots, which dates back to the 15th century, has evolved into a vital aspect of the conclave’s rituals aimed at ensuring transparency and preventing tampering, particularly in response to historical delays in papal elections that incited public unrest.
A blend of tradition and modern engineering
Despite advancements in modern communication, the Vatican has chosen to uphold this tradition of smoke signals as a means of maintaining a connection to the past. Candida Moss, a theology professor at the University of Birmingham, remarked, “From antiquity, people have seen rising smoke as a form of human communication with the divine.” In Catholicism, smoke is symbolic of prayers ascending to God, enhancing the sacred atmosphere surrounding this pivotal moment.
Within the Sistine Chapel, two temporary stoves are installed to handle the election process: one for burning the ballots and the other for producing the smoke signals. These stoves are connected to a flue that extends through the chapel roof, securely leading smoke outside. Recent preparations included firefighters ensuring the chimney’s proper installation and technicians meticulously assembling the stoves within the historic chapel, which houses Michelangelo’s renowned frescoes and is not inherently designed for smoke signaling.
This delicate operation requires careful planning; technicians either utilize existing openings or create temporary access points for inserting the flue—crafted from materials like iron or steel. Every joint is sealed to prevent smoke leaks, and rigorous testing ensures functionality. Kevin Farlam, a structural engineer with experience in heritage properties, emphasized that any technical failure could escalate into an international incident, making precision critical.
To produce clear smoke signals, technicians utilize specific chemical mixtures. Professor Mark Lorch from the University of Hull elaborated, “For black smoke, a mix of potassium perchlorate, anthracene, and sulfur is used, while white smoke results from burning a combination of potassium chlorate, lactose, and pine rosin.” This precise formulation eliminates confusion that arose in the past when natural materials like straw were used, sometimes resulting in ambiguous gray smoke.
Accompanying the smoke signals, the ringing of bells—a tradition established during Pope Benedict XVI’s election—serves as additional confirmation of the new pope’s election. While there have been calls to modernize the system with features like colored lights or digital alerts, the Vatican remains committed to preserving the ritual’s tradition and mystery. As Professor Moss noted, “This is about tradition and secrecy, but it has real theological heft to it as well.” The intersection of faith and ritual continues to guide the Vatican’s approach to communication during such significant moments.