Installed in the late 1980s after the Victorian square was renovated into a postmodern shopping gallery, it swung to and fro for decades, tracking the path of the Earth’s rotation.
Yet, time has taken its toll — and the pendulum no longer serves as a living science experiment in Glasgow City Centre.
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For the last several years; it has been dormant, frozen.
It is my first time in Princes Square and as I ride an escalator to the basement level, I’m keen to see what the fuss is all about.
Because after years of inactivity, science-minded Glaswegians have launched a campaign to get the pendulum swinging again.
The pendulum, viewed from above. (Image: Josh Pizzuto-Pomaco) Glasgow City Heritage Trust boss Niall Murphy tells me that he first noticed the pendulum was no longer working while he was at lunch in the gallery last week. After checking the weight, he found it had been deactivated.
Created as an experiment by French scientist Leon Foucault 170 years ago, the pendulum’s oscillation over a 24 hour period demonstrates the Earth’s rotation. There are at least 130 Foucault pendulums across Europe, including 12 in the UK.
Murphy tells me: “The pendulum is part of the original set-up in Princes Square. It’s one of the small details that make the space feel very special and adds to the sense of place.
“It was made by the California Academy of Science in San Francisco back in the 1980s, around the same time ‘Foucault’s Pendulum’ by Umberto Eco was written, funnily enough. It has travelled a long way to be here.”
Murphy says the shopping centre, which was named as Scotland’s favourite building in 2016, is a “great place” and “fantastic space” which houses a lot of unique details paying homage to the city’s artistic history.
Sitting adjacent to Buchanan Street, the shell of the building was designed in the 1840s, before being renovated and covered with a glass atrium in the late 1980s. The site was sold to property developers M Core in 2024.
“It is a really good example of a postmodern space in the city. Ironically, directly opposite from where the pendulum is in the basement there is a heritage wall,” Murphy notes, “which highlights all the different and unique features of the building.”
The pendulum was installed in the 1980s, as this photo shows. (Image: Josh Pizzuto-Pomaco) The pendulum is easy enough to find, located at the centre of the building and wedged in between seating for Zibibbo and il Pavone restaurants.
Patrons sip cocktails and nibble on tapas as I peer at the abandoned pendulum, snapping photos from several angles. I must look quite strange.
Ironically, the wall that Murphy mentioned hails the pendulum as a key “design feature” of the building, with one excerpt stating: “In 1851, Jean Bernard Leon Foucault, the French physicist, demonstrated a free-swinging pendulum suspended from the dome of the Pantheon in Paris to conclusively prove that the Earth rotates.
“A weight suspended in this manner continues swinging in one direction relative to the sun while the Earth rotates. The northern hemisphere’s anti-clockwise rotations produce an apparent clockwise rotation of the pendulum. Magnets have been mounted at the tip of the cable to counteract air resistance and gravity.”
A petition calling on the centre’s owners to reactivate the pendulum was created in July 2023, but lay dormant until a surge of interest this week.
Paul Sweeney MSP, who is keenly aware of the importance of retaining Glasgow’s heritage, tells me he is backing the petition.
He said: “Glasgow is lucky to have a Foucault Pendulum in Princes Square, but it is a shame to see it is no longer working.
“Reactivating the pendulum would be tremendous for Glasgow. It would allow Glaswegians to continue to marvel at the remarkable scientific discovery, and it would show a willingness to preserve scientific heritage in public spaces.
“I will be writing to the management of Princes Square to ask them to ensure that the pendulum is in working order and I encourage people to take a few minutes to sign the petition.”
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In the depths of Princes Square, huddled between tables of people eating lunch and the hurried footsteps of passersby, I gaze at the pendulum, now still. I’m met with a wave of nostalgia.
You see, this is all oddly familiar.
Growing up near Philadelphia, a highlight of the school calendar was a trip to the Franklin Institute, an ornate science centre named after Benjamin Franklin, he of key and kite.
At the heart of the museum, near the IMAX screen and planetarium, hangs a Foucualt pendulum, four stories off the ground. It has swung for more than 80 years, with a 85 foot wire pulling a 180 pound orb from side to side.
It’s a memory I have tucked away in the back of my psyche, faint and faded — but the magic remains.
Sadly, that sense of wonder appears to have been lost in some quarters.
The Benjamin Franklin Institute is located in Philadelphia. (Image: Dan Mall/Unsplash) As campaign organiser Ethan Slater wrote on Change.org: “The motionless Foucault’s Pendulum in Princes Square has left a lasting impact on those who frequent the area. Its stillness has deprived people of a captivating spectacle.
“The absence of this intriguing pendulum robs the community of a unique educational and cultural experience, as it once served as a source of wonder and curiosity, especially for students and science enthusiasts.”
This is an issue which goes behind the glass walls of Princes Square.
As Murphy notes, the fate of the pendulum mimics what is taking place across the city, as historic motifs and architectural flourishes are being removed.
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The heritage boss tells me: “There are a lot of details in the building which are all to do with the Tree of Life — a lot of Mackintosh’s designs play on this theme.
“Some of these details are being lost — they’ve been covered over and are disappearing. It’s somewhat depressing.
“It’s unfortunate, because features like the pendulum add to the sense of place for these buildings. But no one seems to care. We need to fight against this attitude.”
Indeed, apathy is one of the biggest challenges in the battle to maintain the built fabric of Glasgow.
How do we convince Glaswegians that beauty deserves to be protected, that the buildings around us tell a deeper story, one which is lost when they end up gutted or on the scrap heap?
Perhaps, it is as simple as looking up — and embracing the magic and wonder once again.
