Michelangelo’s dome in Rome: catastrophe avoided

St. Peter's Basilica in Rome (image from the cover of "Saving Michelangelo's Dome"

Skirting danger in Renaissance Italy

A conversation with Wayne Kalayjian, the author of “Saving Michelangelo’s Dome: How Three Mathematicians and a Pope Sparked an Architectural Revolution”

by Bondo Wyszpolski

Saint Peter’s Basilica in Rome is so spacious inside that the Statue of Liberty, pedestal and all, could stand upright and not scrape the top of the dome. This “architectural jewel of the Roman Catholic Church” took more than 80 years to build. Afterwards, cracks began to appear. A century and a half later the situation was dire and, although many people who should have known better chose to ignore or downplay the possibility, the dome was on the verge of collapse. Had that happened, it would have been one of the greatest catastrophic failures in architectural history.

And so the day arrived when a crucial decision became urgent, one that would not only repair the visible damage but ensure the stability of the structure. This would require the close collaboration of key individuals who had to step up and step in before it was too late. The clock was ticking, although no one really knew when time would run out. The story of what conspired to “saving Michelangelo’s dome” was what fascinated Wayne Kalayjian. He delved into the records and documents of centuries past to uncover who was involved, what happened, and why it happened. The result of that investigation is his first book, published this month.

Kalayjian is a civil and structural engineer, and we met recently at his office in El Segundo. He was raised in a suburb of Boston, did his undergraduate work at Tufts, and then his graduate studies at Stanford and the Massachusetts Institute of Technology. After 13 years back in Boston, Kalayjian moved west in 2003 with his wife and daughter. “I’d never heard of P.V.,” he says, but after looking around for a good school system the family settled in Lunada Bay, which he compares in its serenity to a New England village.

But let’s leave the Peninsula for a few minutes and head over to Renaissance Italy.

The inner shell of Michelangelo’s dome, inside of St. Peter’s Basilica in Rome. Photo by Wayne Kalayjian

Gravity is a downer

There’s nothing like a timeline to help get our bearings. Construction on St. Peter’s Basilica began in 1506 and was finished in 1590. The dome itself was built between 1588 and 1590. Later, the dome was crowned by a lantern, which added another 63 feet to the height of the structure, and topped by a “palla” (or ball, with its cross). All in all, from the base of the drum, which supports the circular attic, which in turn supports the dome, this assemblage stretched to about 250 feet, or some 25 stories. The total weight was in the ballpark of 133,000 tons. Or, as Kalayjian puts it, 18,500 midsize cars.

Michelangelo didn’t come aboard with his designs for the dome until around 1550, although other drawings had already been approved, specifically those of Donato Bramante, who was there at the groundbreaking, so to speak, and “had envisioned that he would design the most glorious church in Christendom.” However, 20 years after Bramante’s death, Antonio da Sangallo the Younger brushed aside the original plans for the dome and submitted his own. Michelangelo actually resuscitated Bramante’s designs, although definitely adding his own two cents. I suppose one could argue for it being equally Bramante’s dome rather than just Michelangelo’s, but clearly the latter has more name recognition.

Either way, neither Bramante nor Michelangelo were around to see the final product, Michelangelo dying just shy of his 90th birthday in 1564. We now have to jump ahead another 20 years, to when Pope Sixtus V was elevated, who then cracked the whip and said, “Let’s get this show on the road,” or words to that effect. The project went into overdrive and was completed in May, 1590. Three months later the pope was dead.

The basilica itself, which was finally consecrated by Pope Urban VIII in 1626, stood at 448 feet, which is about as high as the Great Pyramid of Giza. Inside, floor to ceiling, the distance was 386 feet (enough room, as we said, for the big lady in green).

Now we take an even bigger leap, to 1740 when Benedict XIV becomes pope. He was only two years on the job when “darkening rumors” reached him that the dome “might weaken and possibly collapse.”

Although Kalayjian wisely focuses on just a few key players, the supporting cast probably equals the number of extras that William Wyler used for “Ben-Hur.” What we need to know at the moment was that, fortunately, Benedict XIV was what we might call an enlightened pope, and so he went about consulting with as many experts as possible. The solution, though, had to wend its way around the fact that the original design records were scanty and that architects with dome construction experience were few and far between.

Wayne Kalayjian in his El Segundo office. Photo by Bondo Wyszpolski

To fix or not to fix

In those days, one couldn’t Google “dome repair” or domesRus and come up with a quick fix. But the pope had cast a wide net and this is how the three mathematicians of the book’s subtitle enter the picture: Roger Joseph Boscovich, François Jacquier, and Thomas Le Seur. These men were Neutonians (after Sir Isaac), which means that they approached the problem of dome compression mathematically rather than through intuition and guesswork, which had been the rule of thumb since day one.

Boscovich, Jacquier, and Le Seur met with the architect Luigi Vanvitelli, and in September of 1742 they did a walkthrough of the basilica, up and down the inner stairwell that led to the top of the dome, where they noted many cracks, some disturbingly wide and long.

Vanvitelli, however, waved off the urgency of the situation. Kalayjian says that, today, the area would immediately be cordoned off as dangerous. But not then. “This is because there is nothing simple about a dome. The way that it absorbs and distributes its thrusting force is tricky to predict, even under the most straightforward conditions.” The unknown factor is compounded by the variety of materials employed since each has its own set of physical and chemical properties.

In January of 1743 the three mathematicians submitted a paper, referred to as “Parere,” which consisted of analyses and recommendations for repair. In their view, the problems began after the 2,500 ton lantern was placed atop the dome (in relatable terms, 1,500 midsize cars). That extra weight started to throw everything else out of whack. But the important point to be made is that what Boscovich, Jacquier, and Le Seur presented in their report was based on precise scientific calculations. It was, in theory at least, the end of construction relying on conjecture and speculation. And as Kalayjian points out, this was where and when the field of engineering was born. Unfortunately, it wasn’t duly noted at the time and no one brought out champagne.

That’s because a second report was presented to Pope Benedict XIV, this one by Vanvitelli and his team. Enter Giovanni Gaetano Bottari, who became a flea in the pope’s ear; and whether out of envy, jealousy, or a petty resistance to new ideas, he inveighed against the three young mathematicians. Swayed by Bottari’s words, the pope turned to Giovanni Poleni, with creds as one of Italy’s, and Europe’s, preeminent scientists, who then “became an integral part of the solution to fix the cracks at Michelangelo’s dome once and for all.”

“Saving Michelangelo’s Dome”: the cover (published by Pegasus Books)

Stated simply, the dome of the basilica was pressing downward and out. Left unattended, gravity would win the battle. Despite his stature in other matters, Poleni didn’t quite grasp the interrelatedness between the dome and the drum supporting it. He had come from Padua to Rome and with Vanvitelli inspected the dome on some 18 occasions. For all that, he also didn’t see an imminent danger of collapse. Now, because up to this point they appeared to be the true heroes of this story, it’s both surprising and shocking when Kalayjian tells us that our three mathematicians “were excluded from any further input or involvement under Michelangelo’s dome.”

Despite their conclusion that catastrophic failure was not imminent, Poleni and Vanvitelli recommended that iron bands be wrapped about the dome’s outer shell as well as at the base of the dome.These bands can be likened to the staves or hoops of a barrel or cask.

Banding the dome

Kalayjian goes into some detail about the five rings that were deemed sufficient, their placement, weight, and material, and especially the utmost importance of there being no weak links in the chain. The first of these hoops was the longest, 570 feet, and weighing nine tons. Each of 36 bars had to be lifted by hand, winched and hoisted to the rooftop terrace. Workers on scaffolding sculpted the cavities in which the iron bands would be set. The bars were then carried in, laid out in a horizontal arc around the circumference of the drum, each bar coupled to its neighbors. After they’d all been inserted and the connections hammered tight, the cavities were sealed and covered with panels. The first two hoops, for the drum and the attic, took four months to install, and this was finished in March, 1744.

The third and fourth hoops were placed much higher, 300 feet up from the floor. This was completed in July. The fifth and final ring was inserted even higher, at 330 feet. At this point, the construction crew was higher up than the Statue of Liberty, pedestal to torch top, which stands at 305 feet. The work was completed in December, 1744, the project having begun 18 months earlier. Of course the question lingered: Was this enough? Would the fix endure?

But perhaps you’ve been wondering, and I know I was, “How did those guys get up there?” There weren’t any cranes, and steel was only first fabricated in England during the 1750s. Furthermore, no one wore hardhats, safety goggles, or safety harnesses; there weren’t nets to catch anyone if he fell, and Thomas Edison didn’t create the incandescent lightbulb until 1879.

Sketch with bands added to support the dome.

The man who saved the day, who made the repairs possible, was Niccola Zabaglia. Although he could neither read nor write, he had designed innovative scaffolding in ways that would keep his workers safe. After all, you don’t get another lease on life if you topple 300 feet to a hard surface.

But Zabaglia’s job wasn’t over yet. In 1747, one of the original chains from 150 years earlier was discovered to have broken, and so a sixth hoop was prescribed, to be installed way, way up towards the top of the dome. Zabaglia and his team had to reconstruct the scaffolding one last time. By 1748 it was all done.

“Saving Michelangelo’s Dome” has an all-star cast of architects, scientists, philosophers, mathematicians and popes, but “Finally there are the intrepid builders, without whom the dome could not have been built in the first instance or fixed in the next.” Amen.

A surefire tale?

Every person who reads Kalayjian’s book will come away impressed by certain characters, and in my case they are Pope Benedict XIV, the right man at the right time, and Niccola Zabaglia, ditto.

“I agree that different characters will resonate with different readers,” Kalayjian replies, “and I think Zabaglia is my favorite. I love the fact that he was so well loved by the people he was supervising, because construction is full of risks and there is a lot of injury. He wanted to make sure his people were safe up there, 300 feet off the ground. What I love about the pope is that he had a great sense of humor. But he also had a temper, and no patience for people who had underhanded techniques and were manipulative. He would lay into them, in the words of the book, with ‘startlingly uncardinalish vocabulary.’” He laughs. “I love that.”

Kalayjian points out that all of his characters had endearing qualities. “I tried when I could,” he says, “to bring in their personal lives to show that they were real people. They went through ups and downs. They had sorrows.”

Before he began the actual research and writing, Kalayjian knew that he had, in his words, an amazing story. He also saw it as “a great way to talk about engineering and how it’s so interconnected with our architecture, religion, politics, social movements, science and mathematics.” Furthermore, it all took place during the Italian Renaissance and involved Michelangelo, St. Peter’s Basilica, and Rome. It seemed like a sure bet, as long as the writing was concise and straightforward, which it is.

But Kalayjian also insisted on recounting the tale in real time, as if the events were still unfolding and no one yet knew the future outcome. There would be a suspenseful element to it, history still baking in the oven. He envisioned for his book a target audience of 85% being like his sister, “who’s educated, but not really engaged in scientific study, who just wants a good story.” The remaining 15% of readers, he hopes, will be engineers or scientists who’ll be able to acknowledge the depth of his research and at the same time realize that he didn’t go overly technical so as not to lose his core audience, the layperson, again like his sister who wants an easy to follow yet riveting tale. “That was my goal, and I hope I did it.

Time and effort

“If you read the book,” he continues, “you’ll see that it’s kind of sequential. In fact, a lot of these things were happening at once,” and many others were intertwined. “It was very circular, but I couldn’t just jumble everything together; I had to tell it in some kind of linear fashion.” Which he does, to his credit.

He also wrote each chapter — there are 11, plus an epilogue — in sequential order. That’s not to say, for example, that Kalayjian didn’t have material earmarked for chapter seven or eight while still writing chapter three or four.

“That’s the beauty of an outline,” he says. “I’m fairly well organized, but I had to be even more organized for this — and I had to stay focused. I realized that if I didn’t write the chapters in sequence, and think about them in sequence, it would be very easy to start wandering off the reservation and going down rabbit holes.”

So he would allot himself three weeks for one chapter (more or less) before going on to the next chapter, again for about three weeks, and he’d send them off, one after the other, to his agent, Laurie Abkemeier. She in turn would read and critique them, mostly to ensure that her client was keeping focused and on track. Working in this manner, Kalayjian says, “forces you to think about the project in a linear, pragmatic way. You got to get it done.”

At this point, he continues, “I’m writing two hours in the morning before work, three hours after work, or five hours on the weekdays. Probably putting in eight hours on Saturday and maybe six to eight on Sunday. And you’re working: you cannot dabble. People who think they can write on their own schedule, no, it doesn’t work that way.”

There’s also the risk of losing one’s momentum, Kalayjian says. “If you put it down for a few days you kind of lose your motivation, you lose your propulsion. And so I had to keep writing and writing, and there were days when I was going to bed at 1 a.m. and I’m getting up at four in the morning. It’s kind of exhausting but you just do it. That’s how I approached it. It was my madness… It was more than that. It’s a contract; you are married to it, and you cannot lose sight of your obligation to get it done.”

“Saving Michelangelo’s Dome” author Wayne Kalayjian. Photo by Bondo Wyszpolski

Digging up the past

Of course, before he could actually sit down and write — and much of the writing took place in the Malaga Cove Library — Kalayjian had to track down books and papers, esoteric or otherwise, which seem a daunting task until until one actually begins (when it may get even more daunting!).

“The research was very hard,” he says, “especially at the beginning, because you don’t know the story very well.” But one source, or bibliography, leads to another. “It was remarkable how many sources I needed to piece the story together,” and in part that was because Kalayjian wanted to learn as much about each character as he could, and he singles out, as examples, Pope Benedict XIV and Giovanni Poleni. “Finally, after nine, ten months of just dedicated research you get to know the story.” It’s only then that you know what you need to flesh it out.

Asked where he went to do the bulk of his research, Kalayjian mentions the Huntington, in San Marino, Princeton’s Marquand Library of Art and Archaeology, and the Getty Research Institute. Rachel Nutt at Princeton and Tracey Schuster at the Getty helped him secure many of the images that appear in his book, some of them quite rare but also beneficial to the reader, such as depictions of the scaffolding created by Zabaglia in order to carry out repairs on the dome.

Apart from conveying a sense of what people in the 15th century were like, “I tried to talk about the context of the times they were working in, the politics, the religion, the scientific movements, the Enlightenment, and what it was like to live in those days. What were the limitations of their technology? What did they know, and what didn’t they know? What was it like to build something that you couldn’t run numbers for? I mean, when I design something I have a calculator, and we use computers to design them. But they didn’t have any of that. How did they do it?”

Early on in his research, Kalayjian was in for a surprise:

“When I started I thought it would be a very clinical story about the dome. Well, the dome is the central part, but it’s the people around the dome that make the story — and I had no idea I was entering that story. And I realized it was the way they worked together, the way they collaborated, and the way they interacted, that was half the story. Learning about these characters and how they did it. It was fabulous.”

A closer look at the inner shell of St. Peter’s Basilica. Photo by Wayne Kalayjian

Bringing them to life

But Kalayjian also admits that initially the abundance of unusual names “was overwhelming. I was so inundated, but you keep at it,” and in this way the key players emerge from those with a minor role.
Did he consider adding capsule biographies at the end of his book, which the reader could turn to for guidance?

“It’s interesting you said that,” he replies; and then Kalayjian goes on to explain that his epilogue, which follows chapter 11, focuses on seven key characters and recounts what happened to them in the aftermath of their involvement with the dome. Boscovich, Jacquier, and Le Seur, the three mathematicians, were still in their 30s, and they went on to have stellar careers, especially Boscovich, who authored some 108 papers on diverse topics over a span of 50 years, including “theories on molecular science that are a century ahead of his time.”

His agent, however, initially wasn’t sold on the epilogue and preferred he end the book at the conclusion of chapter 11, which is titled “The Advent of Modern Engineering.” In this chapter Kalayjian talks about the development of engineering in the wake of “Parere,” the report presented to Pope Benedict XIV by the three mathematicians. Suddenly, we’re introduced to a new set of characters like Bernard Forest de Belidor, Charles Coulomb, Claude-Louis Navier, and Abraham Darby, who have nothing to do with the kernel of Kalayjian’s story, and which places a burden on the reader to try and integrate them into the focus of the book. This detour, as such, prevents us from going straight into the epilogue, which is a nice dessert for those wanting to know what was in store, in later years, for the major characters.

Kalayjian went on to convince his agent that an epilogue would indeed serve his readers’ interest. After that, apart from the usual editing and fact-checking that accompanies any book released under the auspices of a major publishing house (Pegasus is distributed by Simon & Schuster), the sailing was smooth and the ship, in brief, entered the harbor.

“I say this sort of tongue-in-cheek,” Kalayjian adds, “but for my name and Michelangelo’s name to be linked in any way — and I mean this with all sincerity — is both thrilling and humbling.”

During those months of writing “Saving Michelangelo’s Dome,” which he admits was often a lonely endeavor, Kalayjian’s characters became, in a way, his friends, and he wanted to do right by them.

“As I was getting through chapter 10 and into 11 and 12, I asked myself on at least two or three occasions, ‘Would they be happy with the way I was telling their story?’ I really wanted people to see it the way they would have seen it. I wanted to bring these characters to life because they were wonderful characters.”

Wayne Kalayjian will be doing just that when he discusses and signs copies of “Saving Michelangelo’s Dome” from 2 to 3 p.m. on Saturday, March 30, in the Malaga Cove Library, 2400 Via Campesina, Palos Verdes Estates. (310) 377-9584. PEN


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