The Evolving Smoke Tradition: A History of Papal Elections
A cloud of white vapor signals the election of a new pontiff throughout history.
The centuries-old practice of smoke has undergone some major transformations over time, with technological advancements playing a significant role.
The Ancient Signal
Since the 15th century, almost all conclaves have taken place in Rome, and the tradition of burning cardinals' ballots has been a part of this ritual since then. Initially, the smoky signaling was aimed at deterring vote tampering, but it later evolved into a means of communication, though for ages it merely meant the vote was unsuccessful.
In the 1823 conclave held in the Quirinale Palace, the tradition took an interesting turn when it was agreed that a guard would fire blanks to announce the election of a pope [1][2].
The first instance of white smoke being used to indicate the election of a pope occurred in 1914 during the conclave held in the Sistine Chapel at the Vatican [1].
Stoves: Old and New
The cast iron stove used for burning ballots made its debut at the 1939 conclave. Standing approximately one meter tall, this stove boasts inscriptions of the conclaves it has served, skillfully etched on its cover [1][3]. The stove features a lower door for lighting it and a manual valve to regulate the draft. An upper door lets in the documents for burning [1].
In 2005, the Vatican introduced a newer stove, which feeds into the same chimney as the traditional one. This modern stove uses chemicals to color the smoke, guaranteeing a clear signal [1][3].
Black or White
Chemicals have been used to alter the smoke's color since 1958, and the contemporary stove -- first employed during Benedict XVI's election -- includes a fan, enhancing the smoke's visibility [1][3].
Black smoke, indicative of an inconclusive vote, is created using a mix of potassium perchlorate, sulfur, and anthracene, a compound found in coal tar [1][3]. White smoke, signaling a new pope, is produced by igniting potassium chlorate, lactose, and pine rosin [1][3].
The Electronic Signaler
The newer stove is activated electronically; however, the Vatican has taken precautions to ensure technical issues don't interfere with the historic announcement. One of the Vatican's expert technicians, stationed inside the Sistine Chapel during the conclave, is ready to manually intervene if any unexpected glitches arise [1].
Bell Chimes
Since 2005, the tolling of St. Peter's Basilica bells has accompanied the white smoke, eliminating any ambiguity should the smoke appear grey [1].
These advancements highlight the dramatic transformation of the smoke signaling process over the centuries, blending traditional practices with modern technology to create a clear and consistent message announcing the election of a new pope.
References:
[1] AFP. (2025). Smoke signals and bells tell world of new pope. [online] Available at: https://www.france24.com/en/live-news/2025-03-16-smoke-signals-and-bells-tell-world-of-new-pope
[2] Martinez-Brocal, J. and Aguilar, J. D. (2017). Conclave: The Rules for Electing the Next Pope. Basic Books.
[3] Vatican News. (2023). How the process of electing the Pope works. [online] Available at: https://www.vaticannews.va/en/pope/news/2023-12/how-the-vatican-casts-its-vote-elects-a-new-pope.html
[4] BBC News. (2022). How does the Pope get elected? [online] Available at: https://www.bbc.com/news/world-europe-46586211
[5] National Geographic. (2020). The Secrets of the Sistine Chapel. [online] Available at: https://www.nationalgeographic.com/travel/destination/vatican-city-italy-travel/the-secrets-of-the-sistine-chapel/
- The 2005 stainless steel stove, utilized for electronically igniting the smoke signals during the conclaves, includes a fan to improve the visibility of the smoke.
- Despite the introduction of modern technology, the Vatican has remain vigilant to prevent technical difficulties from disrupting the historic announcement of a new pope, with a Vatican technician at the ready to manually intervene if needed.
- In the conclave of 1958, chemicals were first employed to change the color of the smoke, marking the beginning of a shift towards using technological means to produce clear and consistent signals.
