Sophie Germain & Marc Seguin

There’s something deliciously ironic about standing beneath the Eiffel Tower and craning your neck to read the first name etched in golden letters on the northwest corner: Marc Seguin (NW01).

The man who revolutionised French transport with his suspension bridges, whose engineering prowess earned him a permanent spot on the world’s most famous iron monument. A well-deserved honour, no doubt.

But here’s the rub: the woman whose mathematical work holds up the tower you’re admiring? Not mentioned. Not anywhere. Not even a footnote.

A Man with His Name in Gold

Marc Seguin (1786-1875) was the sort of engineer who made things happen. While others debated theory, he built France’s first suspension bridge at Tournon-sur-Rhône in 1825.

Picture this: a 170-metre span held up by nothing but iron cables and mathematical faith. Revolutionary doesn’t begin to cover it. Seguin’s bridges opened up regions that rivers had cut off for centuries. Lyon to Saint-Étienne suddenly became a manageable journey rather than a geographical impossibility.

But Seguin wasn’t content with just bridges. He invented the fire-tube boiler for locomotives, making steam engines practical for long-distance rail transport. The man had the Midas touch when it came to infrastructure.

His name on the Eiffel Tower? Earned.

The Invisible Woman

Now meet Sophie Germain (1776-1831).

While Seguin was building bridges, Germain was developing the mathematical theory that would make those bridges—and eventually the Eiffel Tower itself—structurally sound.

Her work on the theory of elasticity was groundbreaking. She figured out how materials bend and flex under stress without breaking. Not just iron or steel, but any material. The mathematics that predicts whether a beam will hold or snap under load.

Here’s where it gets properly mental: Gustave Eiffel used Germain’s elasticity equations to calculate the wind resistance and structural integrity of his tower. Her mathematics is built into every beam, every joint, every connection.

The tower stands because of Sophie Germain’s brain.

The Cruel Arithmetic of Recognition

Sophie Germain had to pretend to be a man to do mathematics.

In 1776, women weren’t allowed near the École Polytechnique.

She borrowed a male student’s identity to access lectures and assignments.

Her work on Fermat’s Last Theorem and elasticity theory was groundbreaking, yet she remained in the shadows whilst corresponding with the likes of Gauss and Legendre.

A century later, Einstein and others stood directly on her shoulders. Germain’s elasticity equations—describing how materials bend and stretch—gave physicists the mathematical toolkit to understand how space itself could warp.

Her work on elastic surfaces became his curved spacetime. Where Germain faced exclusion, Einstein found fame. Both saw patterns in chaos, but history has been rather more generous to the patent clerk than to the woman who had to steal her education.

In 1831, the University of Göttingen finally—finally—decided to award Germain an honorary doctorate for her contributions to mathematics and physics.

She died before the ceremony.

The Foundation Nobody Mentions

As the first post in this series, this deserves emphasis.

Sophie Germain’s work on elasticity wasn’t just theoretical.

It was practical, applicable, and revolutionary.

Without her equations, modern engineering would have taken decades longer to develop.

She didn’t just contribute to science—she fundamentally changed how we understand the physical world.

Yet walk around the Eiffel Tower today, and you’ll see 72 names celebrating the giants of 19th-century French science and engineering. Not one woman among them.

That’s not history.

That’s editing.

Time, then, for a new Restoration.

Next week: We’ll meet astronomer Lalande and the woman who was paid to map the stars while he was still learning to hold a telescope steady.

That’s my two penn’orth.

Live well, stay curious, and remember—foundations often can’t be seen.

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I love writing, and I’m never short of ideas. They aren’t all good ones, of course! Nonetheless, I had plenty of material in various stages of completion when I tripped over the fact that there are 72 name plaques at the base of the Eiffel Tower.

No matter how prolific my supply of mostly mediocre ideas is, when fortune hands you a 72-post Substack series, that’s still exciting. Little did I know just how deep that rabbit hole would go.

The Question That Started It All

“Find a list of the figures commemorated on plaques on each side of the Eiffel Tower. Are the plaques officially numbered?”

Simple enough, I thought—a quick search, job done, then back to Murderbot.

How wrong I was.

What I Found in the Rabbit Hole

It turns out that the Eiffel Tower is adorned with the names of 72 French luminaries – scientists, engineers, and mathematicians who lived between 1789 and 1889. They’re around the first-floor balcony in golden letters about 60 centimetres tall, large enough to read from the ground if you crane your neck.

I took a little artistic licence with the Substack thumbnail!

Gustave Eiffel had these names inscribed as his “invocation of science” – essentially thumbing his nose at the artistic establishment who’d called his tower “a gigantic black factory chimney”. Clever bloke, our Gustave. Can’t argue with science, can you? Especially before the invention of social media.

The names are split across four sides, each facing different parts of Paris: the Trocadéro side, La Bourdonnais side, the Military School side, and the Grenelle side. Eighteen names per side, arranged “in a random order” – though modern cataloguers have imposed a numbering system (NW01-18, SE01-18, etc.) for reference purposes.

The Elephant up the Tower

Here’s where it gets interesting. The list contains no women. Not one.

The list has been explicitly criticised for excluding Sophie Germain. She’s a noted French mathematician whose work on the theory of elasticity was used in the construction of the tower itself.

That’s a pretty egregious omission. Worse even than using ‘g’ without mentioning Isaac Newton’s apple, or discussing hydrogen-fuelled vehicles without posting a picture of the Hindenburg or R101.

In 1913, John Augustine Zahm suggested that Germain was excluded because she was a woman.

The Lightbulb Moment

As I stared at this roll call of exclusively male brilliance, something clicked.

For every Lagrange, Laplace, and Lavoisier etched in gold on those iron beams, there was likely a woman of equal brilliance working in the shadows. Women who faced barriers that their male contemporaries never encountered. Women whose contributions were minimised, overlooked, or attributed to the men around them.

Times were different then. Scientific academies didn’t admit women. Universities barred them from lectures. Publishing required the use of male pseudonyms or male co-authors. The whole system was rigged like a dodgy fruit machine.

But here’s the thing – they were there. Working. Discovering. Inventing. Creating.

What We’re Doing About It

So we’ve created something rather special.

A master list of all 72 names on the tower, arranged in the order you’d encounter them walking clockwise around the Iron Lady. But here’s the twist – alongside each commemorated man, we’ve paired a contemporary woman whose brilliance deserves equal recognition.

This post isn’t about rewriting history or tearing down monuments. It’s about completing the story. For every celebrated scientist reaching for the clouds on the Eiffel Tower, there was often a woman reaching just as high, but fighting headwinds that would have grounded lesser spirits.

Over the next 72 posts, we’ll meet both the lions and the lionesses of science. The men whose names are cast in iron and gold, and the women whose contributions were carved in the harder stone of human progress, often without recognition.

The Ground Rules

We won’t be preachy about it. These were brilliant people working within the constraints of their times. The men on the tower weren’t and aren’t villains for being recognised – they earned their places through genuine achievement. But neither were the women victims for being overlooked – they were playing a game with different rules to benefit their future sisters.

We’re not here to diminish anyone’s achievements.

We’re here to double them.

Ready for the Tour?

French pun 100 per cent intended!

Starting next week, we’ll take a lap around the tower. We’ll meet Marc Seguin (NW01), the suspension bridge pioneer who revolutionised transport, and Sophie Germain, the mathematical physicist whose work on kinetic energy laid foundations that are still solid today.

Then we’ll keep walking, clockwise, and by the time we’re done, you’ll know not just the 72 names that Gustave Eiffel chose to immortalise, but the 72 names that history forgot to mention.

Because every tower needs a complete foundation.

That’s my two penn’orth.

Live well, stay curious, and let’s give credit where it’s long overdue.

Next time: Post 1 – Sophie & Marc: The Golden Name and the Hidden Figure