The Tower of Pisa

To prepare for visiting the famous Tower of Pisa, I *leaned* into a book called Tilt: A Skewed History of the Tower of Pisa, by Nicholas Shrady. The story includes a lot about what was going on in the area of Pisa from about 1073 to the present. Here are some things I learned.

 

Many cathedrals and bell towers were erected using spoils of war to show a city’s power. The Tower of Pisa is different in that it was commissioned by a woman named Berta di Bernardo who left “sixty coins” in her will for the building of a belfry. Work began the next year in 1173. 

 

No one knows who the architect was! This could be because at the time, architects were not esteemed as artists. They were seen as general construction crew. Architecture was not an lofty occupation.

 

Many other towers were made of a solid brick structure and allowed no light into the lower levels. The Tower of Pisa is different because it is made of marble, and the exterior of each level is laced with open arches with doorways that introduce light as you ascend the wide steps. 

 

The proportions of the tower have an interesting connection. The circumference is 100 Pisan feet (approximately 19.5” modern inches) and is 100 Pisan breccia (arms) tall (about 23 modern inches). There are seven upper concourses, and seven enormous brass bells. The walls are 13’ thick. 

 

It took five years to build the first three courses and then work on the tower stopped without a clear reason. 

 

After 98 years, work began again. The tilt in the tower, caused by a soft foundation, was evident by then, but many structures of that time sometimes developed slants, so it was not cause for concern or even a raised eyebrow. The next 3 courses were built at a slight angle from the previous ones to try to balance the visual straightness and perhaps coax the tower back to perpendicular. But the additional weight caused more tilting. Eventually the tower was leaning over its based by more than 4 meters.

 

In 1902, St. Mark’s bell tower in Venice, developed a crack. At 9:30 am on July 14, a police inspector saw the crack ran all the way to the top and debris was strewn about. Inspite of the engineers sayng there was no cause for immediate concern, he made the call to evacuated the tower and the piazza. At 9:47 am, the entire 1000 year old tower fell. 

 

That disaster woke up the stewards of Pisa to prevent the same thing from happening to their beloved tower. More experts were consulted. For years, no clear solution was brought forth. 

 

When Mussolini was in power in 1938, he decided he didn’t need permission, he ordered action. They drilled a bunch of holes in the foundation and pumped in 90 tons of cement trying to stabilize the tower. The result caused the tower to move slightly (read that “shake imperceptibly”) in different directions over the next 8 months, which could easily have caused it to fall. It ultimately settled back in the original position. 

 

In July 1944, we nearly lost the tower, and the U.S. would have born the blamed! U.S. Allied forces were in battle with German occupied Italy at Pisa. The Germans were hitting the U.S. soldiers with amazing precision, and they figured out they were likely using the tower to spot them. Sergeant Leo Weckstein was given the assignment to get as close to the tower as possible and “level it.” He got within range, had the tower in his sights, looking for any movement on the tower so he could fire. The day was hot, and suddenly the vision in his scope was distorted by heat waves. He couldn’t take an accurate shot! Then there was an explosion overhead that rained shrapnel over them so they retreated. They got a radio message, “Get your @$$es out of there! The friggin’ generals have decided to spare the tower anyhow.” That is how close we came to losing the tower. It feels like divine intervention!

 

Ultimately, in 1999, a soil scientist saved the tower. John Burland of London’s Imperial College meticulously tested methods that would remove soil from the north side, allowing the tower to stand more erect. The tower had to be closed for 12 years, hampering tourism and causing local ire, but he was ultimately hailed as a hero for stabilizing, and straightening the Tower of Pisa, but not *too* straight as to ruin what we love about it most—it’s tilt. 

 

Fun facts: 

All workers had to take an oath of loyalty before working on the tower.

 

The finest of the marble was transported by canal to the construction sight and patiently cured in a warehouse to see how it would change in color when exposed to the elements before selecting how it would be used.

 

Most of the artisans were from Pisa. This project was a significant “resume builder” and many were later hired to work on prestigious projects across Italy.

 

You’ve likely heard the story that Galileo dispelled the theory that heavier objects fall faster by dropping two balls of different weight from the top of the Tower of Pisa. Rubbish. It was a story fabricated by his hagiographer (a story of someone meant to highlight or embellish their life, a common practice of the time favored over actual truth), Vincenzo Viviani. The supposed event took place when Galileo was a professor at the University of Pisa in 1589-1591, but the same science was outlined and published by Girolamo Cardano in 1570, a well-known scientist of the time that they both likely knew about.

 

Mary Shelley, author of Frankenstein, moved to Pisa with her husband when she was 23 years old. Her novel Velperga began a bit of a tourism to Pisa. 

 

Dark fact: A powerful lieutenant of the “podesta,” Ugolino della Gheradesca of Pisa was found guilty of conspiracy and treason in 1288. His sentence was to be thrown into the Tower of the Seven Streets (Torre de Fame, or Muda Tower), along with two sons and two grandsons, to starve to death. Perhaps even more disturbing is that this sentence was ordered by the Archbishop Rinardo di Ruggiero.