Vox Meditantis

Olive Wetzel Dennis died on 5th November 1957 – sixty-eight years ago this week. She was seventy-one. But in the quiet of an imagined study, where history bends just enough to allow one more conversation, this civil engineer sits down to reflect on a life spent making trains comfortable, railways profitable, and passenger experience something that mattered. When you’ve travelled half a million miles observing the smallest details of human comfort, you develop a particular patience for questions. We begin there.

Thank you for joining us today, Miss Dennis. I want to begin by asking what many people think they know about you. They imagine a woman who decorated trains – who had an eye for the decorative, the aesthetic. The china designs made you famous, after all. But that framing has rather obscured the work beneath it.

Yes. The china. I designed a china pattern. It was 1927, for a centennial celebration. Blue and white, with scenic locations in the centre and historic locomotives around the edges. I’m proud of it – it was good work. But people have a peculiar habit of remembering what they can see, not what requires thinking to appreciate. A plate sits on a table. One can admire it immediately. But a ventilation system? The engineering that allows a passenger to control fresh air whilst the train moves at sixty miles per hour over coal-fired tracks? That requires understanding.

The press, you see, found me more interesting as the woman who thought about the dishes than as the engineer who designed the window mechanism that made the dishes worth eating around, because passengers weren’t choking on cinder-filled air whilst they dined.

You mentioned the ventilator. That’s a good place to begin, I think – with the technical substance of your work. Walk me through the Dennis ventilator. What problem were you solving, and how?

Now that’s the question. You see, when I began at the B&O in 1920 – first as a bridge draftsman, which was respectable work but not where my mind went – I rode the trains. The mandate was simple: make them more appealing to women passengers, because women represented half the ridership and half the profit. That was the practical truth of it. Daniel Willard, the president, was no romantic; he was a businessman observing an economic pattern.

But once I began riding, I observed problems that had nothing to do with gender and everything to do with physics and human welfare.

The fundamental problem was this: coal-fired locomotives produce tremendous quantities of smoke and cinders. When the weather was warm, passengers needed ventilation. When you opened a window, you didn’t get fresh air – you got clouds of grit and ash. The window screens, fitted to some cars, did trap the worst of it, but they also created draughts, which created complaints. Or the screens simply remained closed, and the car became a box of still air and body heat and increasingly poor quality air.

What was needed was a mechanism that allowed fresh air to enter through a defined, controllable opening whilst a fine mesh screen – very fine, finer than anything in use before – trapped particles. But it couldn’t simply be a screen mounted on the window frame, because then you’ve got the weight problem, the dirt accumulation problem, the passenger’s view being obstructed.

I designed a ventilator that was built into the car wall itself, rigidly attached – no loose parts to be lost or damaged. Outside the car, it presented a simple opening with the fine mesh screen, positioned so the window’s normal motion didn’t interfere. A passenger controlled it from inside using a pull plate that operated a hinged lid. When they pulled the lid down, it opened the screen compartment to fresh air.

The air entered the housing, passed through the screen, was directed upward through perforated plates inside to break any forceful draughts, and then distributed into the car without the concentrated blast that caused complaints. Personal, controllable ventilation. Every passenger at their window could now manage their own climate without exposing themselves to clouds of cinders.

I patented it in December 1927. Patent 1,693,108, registered 27th November 1928.

I’m holding the patent documentation. The drawings show remarkable clarity. But here’s what I want to know: what failed before this worked? How many versions didn’t work?

Ah, now you’re asking about the work that the patent record doesn’t capture. Field testing, my friend. That’s where engineering lives or dies.

I tested ventilation designs for years before I filed. I rode those trains, sometimes in hot weather when passengers desperately wanted air but were choosing between cinders and suffocation. I examined existing screen systems on competitor railroads – I rode the Pennsylvania, the New York Central, studied their approaches. Most were compromises. They solved the cinder problem at the expense of draughts. Or they partially blocked the view. Or they were so complex that passengers and crew both struggled with them.

One early iteration I designed – I won’t bore you with all the mathematical reasoning – trapped the air too effectively. I wanted the screen fine enough to catch the finest particles, but a screen fine enough to do that also resisted air flow more than anticipated. On a test run from Baltimore to Chicago in 1925, I sat in a compartment with one of my prototype ventilators for hours. The air flow was insufficient. You could feel it wasn’t working. I could measure it wasn’t working. So back to the drawing board.

The solution involved understanding both the particle size of coal ash – I collected samples, had them examined – and the precise aperture size of mesh that would catch them whilst maintaining adequate air flow. Too coarse a mesh, and you’ve got cinders. Too fine, and you’ve got a room where air hardly moves. The margin for success was narrower than I initially calculated.

I also discovered that passengers themselves were part of the problem I needed to solve. Some people opened these ventilators fully and left them open, creating draughts. Others wouldn’t use them at all, preferring to suffer rather than risk what they didn’t understand. So the mechanism itself had to be intuitive. Pulling down meant opening. Anyone could understand it. The cam and roller system, which held the lid in whatever position the passenger wanted, meant they could set it to partial opening or full opening or closed. They had control.

The patent assigns all rights to the B&O Railroad.

Yes.

How did that feel?

It felt like the employment agreement I signed. It was, by the standards of the time, entirely normal. When a company employs an engineer and you conceive something in the course of that employment, the company owns it. I understood the terms when I accepted the position. I was not cheated; I was paid a salary, and the salary reflected the work I did.

What I did find frustrating – and it took me years to admit this – was the invisibility. The ventilator worked beautifully. Passengers benefited tremendously. The railroad was proud of it, and rightly so. But when they advertised the innovation, my name never appeared. In 1930, when we were demonstrating the improved ventilation to railway journalists, the feature was credited to the B&O’s engineering department, not to the engineer who’d spent four years perfecting it.

At the time, I told myself it didn’t matter. I was doing the work. The work was good. The passengers were more comfortable. That was the point, wasn’t it?

Now, at this distance – and I’m speaking honestly now, which I might not have done in 1950 – I wish I had known then what I understand now: that credit matters. It’s not vanity. It matters because when a woman’s name doesn’t appear on her innovations, the assumption creeps into the historical record and into people’s minds that perhaps a woman didn’t do the work. Perhaps she was assisting. Perhaps she had a good idea and a man engineered it properly.

I should have insisted on that. My contemporaries in other fields – and I think of my colleague engineers, the men – didn’t lose their names to corporate assignments the way I did. Or if they did, they had decades of other work, publications, professorships that preserved their contributions independently.

But I signed the agreement. I was an employee. This is how it was done.

Let’s step back. You were born in 1885 in Thurlow, Pennsylvania. Your father –

My father gave me tools instead of telling me no. That’s the version that gets told, and it’s true, but it’s incomplete. My parents were reasonably prosperous. My father was engaged in business; my mother was accomplished in her own right. I grew up in Baltimore from age six. I was not exceptional in having intellectual ambitions. I was exceptional in having parents who didn’t crush them.

I was building things as a child – dollhouses, furniture, that model streetcar for my brother. My brother’s streetcar had trolley poles that actually worked. Reversible seats. I understood mechanical systems before I understood arithmetic.

My mother encouraged reading. My father encouraged building. The combination – intellectual rigour and hands-on construction – was unusual for a girl in the 1890s, but my household was unusual. Or perhaps it was more unusual than I thought. Perhaps many girls built things but were simply never encouraged to continue.

You went to Goucher College, then to Columbia for a master’s degree in mathematics. Then you taught mathematics for a decade before pursuing engineering. That’s a curious trajectory.

I was uncertain. I’m being honest with you. I loved mathematics. I loved teaching. I was good at it. But there was this voice – as I said years later, the idea of civil engineering just wouldn’t leave me. It was like a persistent hum at the back of my thoughts.

In 1919, I was thirty-four years old, teaching at a vocational high school in Washington, and I thought: you can do this now, or you can regret it later. There’s no age at which a woman must stop trying if she hasn’t started. I enrolled at Cornell that summer. They had a two-year programme in civil engineering. I finished it in one year.

The dean at the time asked me – quite kindly, actually – how I’d managed it so quickly. I told him I’d been doing mathematics for a decade. The engineering was the application of what I already knew. I also wasn’t interested in socialising the way some students were. I had a specific goal. I attended lectures, I did the work, I passed the exams.

When I walked to receive my degree in spring 1920, someone in the audience – I never saw his face – yelled out: “What the heck can a woman do in engineering?”

Do you know what I thought at that moment? I thought: at least you’re asking. The worst part would have been if he’d simply assumed I was there by mistake, that I’d married another student and was observing. Instead, he asked. It meant he’d noticed. He didn’t approve, but he’d noticed.

And the answer? What could you do in engineering?

I proved it by doing it for thirty years. But the petty version of me says: I proved it by making every train in America more comfortable to sit in. Those reclining seats he probably used later? I designed them. The dimmable lights on an overnight train allowing him to sleep without complete darkness? I engineered that system. The window that didn’t cover him in cinders when he opened it? That was my work.

But we might note that he probably never knew any of that.

When you joined the B&O Railroad in 1920, you were initially a bridge designer. A conventional engineering position. How did the transition to “Engineer of Service” – a position that didn’t exist until you created it – come about?

I was hired by the engineering department to design bridges. I did that work competently. But Daniel Willard, the president, had observed something. Half of the railroad’s passengers were women. Women who had purchasing power, women who made decisions about which railroad to ride, women who influenced family choices about how to travel. Yet the railroad’s offerings, its competitive advantage, were being built around speed and cargo capacity and masculine notions of industrial progress. He was shrewd enough to see that his female passengers, treated as afterthoughts, might become competitors’ customers.

There’s a certain irony in understanding that women represent economic value – being hired because of one’s gender – but using that leverage to build something better for everyone. I’ll say that clearly: I was hired as “the woman’s perspective.” Once I was in the position, I could see that passenger comfort wasn’t a feminine concern. It was a business concern. Everyone wanted ventilation. Everyone wanted to recline when they were tired. Everyone wanted fresh water and soap and the ability to understand the schedule without hiring someone else to read it for them.

Willard was perceptive enough to create the title and give me authority. “Engineer of Service” – it was ambiguous, which meant it could encompass whatever needed encompassing. I could design the mechanical systems. I could redesign the menus. I could study passenger behaviour. I could even, eventually, design a china pattern.

Can you walk me through your methodology? You’ve mentioned riding trains. But there was something more systematic happening, wasn’t there?

Yes. I rode trains, certainly – 50,000 to 100,000 miles annually, over 5,000 miles of B&O track and competitor lines. But I wasn’t just riding as a passenger. I was observing, measuring, asking questions, taking notes.

In the beginning, I travelled coach. I wanted to understand what third-class passengers experienced. I sat on the seats for hours and made notes about pressure points, about visibility from the seat, about whether I could see out the window properly. I lay on Pullman berths to understand mattress comfort – not theoretically, but by actual experience. I took a round-trip to Chicago sleeping on one brand of mattress on the way down and a competitor’s product on the return. Then I did the same comparison to another pair of mattresses.

I measured dressing rooms. I timed how long it took a passenger to understand a timetable. I noted which passengers asked for assistance reading schedules – were they elderly? Were they non-native English speakers? What would make it easier for them?

I observed dining car operations. I watched where bottlenecks occurred. I ate in the dining cars and made notes about the menu, the presentation, the service sequence. I asked passengers what they actually wanted to eat at different times of day. An overnight traveller at 11 PM wants different food than a mid-morning traveller. Airlines would understand this decades later. I understood it in 1921 by asking.

I interviewed passengers – women primarily, but also men, children, elderly people, families, solo travellers. What bothered you? What would improve your journey? What surprised you?

This was methodical. This was data-gathering and analysis before we had formal names for those processes. This was ethnographic research, though I didn’t use that terminology. I was observing how people actually lived – not how they were supposed to live or how theoretically perfect passengers would behave, but how real human beings travelling for real reasons actually experienced the railway.

You measured seats. You sat in dressing rooms. Did you encounter resistance from the railroad?

Initially, some. After a certain point, no. The earliest challenges came from crew members who thought I was strange. A woman in a berth for two nights noting how comfortable the mattress was – that was unusual. A woman measuring dressing room dimensions – what was I doing? Was I inspecting? Was I criticising?

Once Willard made it clear that this was official work, that I had his backing, attitudes shifted. I was no longer a curiosity. I was doing a job the president had authorised.

The genuine intellectual disagreement came from older engineers who believed that comfort was separate from engineering. Engineering was the locomotive, the track, the structural integrity of the bridge. Whether a passenger was comfortable was a matter of service, of hospitality, not engineering. I fundamentally disagreed with that division.

I would argue that passenger comfort is an engineering problem. It involves materials science – what upholstery fabric resists staining but remains breathable? It involves ergonomics – what seat height allows a shorter person’s feet to rest on the floor? It involves thermodynamics – how do we heat and cool a car full of people without creating differential temperatures that cause discomfort? It involves acoustics – how do we manage noise from the wheels whilst allowing ambient sound? These are engineering questions.

Some of the older men came around to this perspective. Some never did. But it didn’t matter, ultimately. The results spoke. Passengers loved the improvements. Other railroads copied our designs. The market validated the approach.

I want to ask you about the Cincinnatian – the entire train designed to incorporate all your innovations. This was in the 1940s?

The actual maiden voyage was 1947. But the work began earlier, during the war and immediately after. The B&O asked me to design a complete passenger train – from the locomotive shroud to the interior configurations to every detail of the passenger experience. It was, in some ways, the culmination of everything I’d learned. Every innovation I’d tested, every complaint I’d heard, every solution I’d developed – they all went into this single train.

I designed a shroud that covered the locomotive engine. This wasn’t decorative – well, it was partly decorative, because I do believe form and function work together – but primarily, the shroud served a practical purpose. It made routine maintenance easier. Mechanics could access components more efficiently. It created an integrated aesthetic that signalled to passengers that this was a modern, unified system, not a collection of separate components bolted together.

The interior was where the real innovation lived. Reclining seats, of course. Stain-resistant upholstery that was actually pleasant to sit on, not the awful scratchy fabric that was supposedly practical. Dimmable lights. Window ventilation systems like the patent I’d developed. Air conditioning. Larger lavatories with superior fixtures. Dining facilities that could accommodate various meal times. Observation areas where passengers could see the landscape. Luggage racks that didn’t require climbing to dangerous heights.

But here’s the thing: none of this was exotic. None of it violated engineering principles or consumed vast resources. It was good design – thoughtful, careful attention to the actual experience of actual people. It was observation applied to mechanics.

“The crowning glory of her career,” a historian has written.

Historian Sharon Harwood said that, yes. I’m grateful for it, and I’m careful not to claim too much. The Cincinnatian was the B&O Railroad’s train. It was their capital, their reputation, their strategic vision. I contributed the detailed engineering of passenger experience. That’s real work. That matters. But I don’t want to overstate my role.

And yet – I should note that when the railroad publicised the Cincinnatian, when they advertised its features and its luxury, my name appeared nowhere. Not in the press releases, not in the advertisements, not in the promotional materials sent to travel agents. The innovations were credited to the railroad. The design was presented as the work of the railroad’s engineering department.

This is where I circle back to what we discussed earlier. At the time, I told myself it didn’t matter. I knew what I’d done. The passengers experienced what I’d designed. That was enough. And I meant it. But sixty years later, when I hear that the Cincinnatian was the crowning glory of “her” career, I note that in the historical record, I’m not always clearly identified as the engineer responsible.

That’s not bitterness. That’s observation. That’s the historical record doing what it tends to do: erasing women from the work they actually performed.

Let me ask you about something that puzzles me. You wrote almost nothing. You didn’t publish engineering papers. You didn’t write a memoir. You didn’t document your methodology. Why?

I was working. Constantly. I was riding trains. I was measuring. I was designing. I was in meetings. I was troubleshooting problems that arose when innovations were implemented. I was travelling to competitor railroads and other companies to study their approaches. I was speaking to groups – women’s organisations, engineering societies, passenger service conferences. The work was my communication.

Publishing requires distance. It requires stepping back from the immediate work to reflect on it, to theorise about it, to document it for an external audience. I didn’t have that distance. I was embedded in the B&O’s operations. Everything I created was immediately implemented. I could see passengers using the reclining seats. I could observe whether the ventilation system actually worked. That feedback was immediate and powerful.

If I had removed myself to write academic papers, I would have been absent from the work itself. For me, the work mattered more than the record of the work.

But here’s what I should have done differently: I should have kept detailed records anyway. Not for publication, necessarily, but for history. I should have documented the problem I was solving, the iterations I went through, the data I collected, the reasoning behind my design choices. Not for anyone’s approval or recognition, but because future engineers – particularly future women engineers – would have learned from that record.

I didn’t do that. I was focused on the immediate. I didn’t think sufficiently about posterity.

You were the first female member of the American Railway Engineering Association.

I was. That’s 1923, I believe. The recognition was meaningful. These were my professional peers – engineers from every major railroad in America. They understood the work I was doing because they understood engineering. They weren’t looking at me and seeing “the woman who designed the china.” They were looking at me and seeing an engineer who’d solved problems they’d tried to solve.

There’s a particular loneliness in being the first of something. You have no peers who share your exact experience. There are no women in the room who’ve already navigated what you’re navigating. There’s no example. But there’s also a particular freedom in it, I suppose. You’re not constrained by “how women usually do things” because there are no women who’ve done it before.

I never sought to be a symbol. But I understand that I became one, whether I sought it or not. Women engineers would occasionally contact me, or I’d encounter them at conferences. They’d say something to the effect of: I saw that you did this, so I knew I could do this. That responsibility was heavy sometimes. I wished I’d had more mentors when I was starting. But I also understood that I could be that for others.

It’s now 2025. Women comprise roughly fifteen to seventeen percent of civil engineers in the United States and the UK. We’re no closer to parity now than we were in your era. What would you say to young women entering engineering today?

First: your work will be brilliant. Trust that. You’ll see patterns other people don’t see because you’ve been taught to see the world differently. You’ll identify problems others overlook because the problems affect you directly. Your perspective isn’t a limitation; it’s an advantage.

Second: do not wait for permission. I waited. I taught mathematics for ten years before I pursued engineering because I was uncertain, because nobody told me it was possible, because I was waiting for the world to make space for me. The world doesn’t make space. You make it. You go to university. You study what you want to study. You apply for the jobs you want. You take the assignments others won’t take. You do the work so thoroughly that they can’t ignore you.

Third: do the work for the work itself. Do it because the problem fascinates you, because solving it matters, because the people who’ll benefit from it matter. Don’t do it for recognition, though recognition has value and you should demand it when it’s owed to you. But if you’re only working for recognition, you’ll go mad when you don’t get it. I know this from experience.

Fourth: and this I’m saying with the clarity of seventy years’ hindsight – insist on credit. Insist on your name on the work. Insist that your contributions be documented. Don’t sign away your intellectual property without understanding the cost. Don’t let others take credit for your innovations. And if you must make those compromises – as sometimes you must, because survival requires it – at minimum, keep detailed records for yourself. Document what you did. Because the historical record is not automatically kind to women, and you owe it to the women coming after you to leave a clear record of what you actually accomplished.

And fifth: choose carefully who you allow to define you. I allowed myself to be defined by the features visible to journalists – the china, the dining car menus, the decorative aspects of my work. I should have more forcefully insisted that I was an engineer, not a decorator. That my work was structural, mechanical, technical. I’m not saying the visible features didn’t matter. They did. But I should have claimed the complete scope of my work, not let others narrow it.

It will be harder than it needs to be. That’s unjust. But your job isn’t to make the world just. Your job is to do good work and to insist on being recognised for it.

Did you ever regret not having a family? A marriage?

I never married, no. I think if I’d wanted to marry, I would have. There were opportunities. But marriage, in my era, meant significant compromises for women. It meant subordinating your work to your husband’s career. It meant leaving your job when children arrived – if you were fortunate enough to have them. My work was my life’s dedication. I wasn’t willing to compromise that.

Did I regret it? Not fundamentally. I was fulfilled by the work. I had a deep friendship with my sister, Hazel. I had professional relationships that satisfied me intellectually. I had the satisfaction of seeing my designs implemented and appreciated.

But I’m not going to tell you there was no cost. There was loneliness sometimes. There was the peculiarity of being a woman travelling alone for weeks at a time on trains, which drew comment and raised eyebrows. There was the assumption by some that my unmarried status indicated something was wrong with me – that I was cold, or difficult, or unsuited to relationships.

I think that assumption itself was the problem, not the unmarried status. A woman’s worth was measured by her marriageability, and if you opted out of that economy, you were suspect. That was the cost of my choice – not that I didn’t have marriage, but that not having marriage meant you were, in some subtle way, marked as incomplete.

The world has changed, I hope. Women should be able to choose marriage or not to choose it without it being a judgment on their character or their femininity or their success. That remains unfinished.

The patents that you assigned to the B&O. When you look back now, do you feel bitter about that?

Bitterness is an indulgence. It implies I was wronged in some clear, objective way. The truth is more complicated. I signed the agreements. I knew what I was signing. The compensation was fair by the standards of the time. I wasn’t cheated in a legal sense.

What I regret is not understanding the value of attachment – the value of having one’s name associated with one’s work. I regret not foreseeing how that absence would affect how I’m remembered. I regret that the ventilator patent, the air conditioning innovations, the seating improvements – all of it is attributed to the railroad, not to me as an individual engineer.

But bitter? No. I’m too practical for that. Bitterness doesn’t change the past. What I do feel is a kind of clarity: future women engineers should know what I didn’t fully appreciate – that your name on your work, that your visibility, that the historical record of what you actually did – these things matter. They matter for your legacy, yes. But they also matter for other people’s futures. When women engineers appear in the historical record, other women know it’s possible. When we’re erased, we become theoretical – “women in engineering” – rather than actual.

I should have been more insistent. That’s what I regret.

You retired in 1951. You were sixty-five. What did you do after that?

I wasn’t very good at retirement. I spoke to women’s groups. I gave talks about engineering, about career, about possibility. I consulted informally with the railroad on various problems. I worked on puzzles – I’ve always loved mathematics and cryptography. I gardened. I read extensively.

But I never fully stepped away from the work. It was too much a part of me. Even when I wasn’t actively solving problems, I was thinking about problems. I was observing passenger experience on trains and buses and aircraft. I was noting where the innovations I’d pioneered were being used and how. I was frustrated sometimes that airlines and buses were implementing my designs without attribution. But I was also quietly pleased that the ideas had spread, that they’d become industry standard.

That was a kind of immortality, I suppose. My reclining seat is on an airplane somewhere right now, being used by someone who has no idea I designed it. My ventilation principle is in a bus window. My observation about the importance of passenger comfort had become so ordinary that it was no longer remarkable. That’s not nothing.

If you could go back and tell the young woman receiving her engineering degree at Cornell in 1920 – the one who’d just heard that heckling question, “What the heck can a woman do in engineering?” – what would you tell her?

I would tell her that the answer to that question is everything. You can do everything. You can design systems that will be used by millions of people. You can see problems that others overlook. You can solve them in ways that improve ordinary people’s lives. You can be excellent at your work. You can be taken seriously.

But I would also tell her: insist on being seen. Don’t let them reduce you to the decorative parts of your work. Don’t sign away your intellectual property without understanding what you’re giving up. Don’t let your name disappear from your innovations. Don’t teach yourself that credit doesn’t matter, because it does. It matters for you, and it matters for all the women coming after you.

And I would tell her: the work will be harder than it should be. People will doubt you. Some will actively undermine you. But there will also be people who see your capability and trust you with important things. Keep track of those people. Work with them. Let them teach you.

And finally: your life doesn’t have to look like anyone else’s life. You don’t have to marry if you don’t want to. You don’t have to have children if you don’t want to. You can devote yourself completely to your work, and that’s not a tragedy. That’s a choice. That’s a life.

But also – and I say this with the wisdom of seventy-one years – relationships matter too. The ones I built with colleagues, the deep friendship with my sister, the professional respect I earned. Don’t sacrifice everything. Find the balance that makes sense for you. The world may judge you for whatever you choose, but at least let it be your choice, not the world’s default.

I think I did all right. I made good choices with the information I had. But I wish I’d kept better records. I wish I’d been more insistent about my contributions. I wish I’d understood sooner that invisibility isn’t the same as anonymity – that I could have done my work brilliantly and also insisted that the world know it was my work.

Maybe that’s the real lesson for the young woman at Cornell: you can change the world. But don’t let them erase the fact that it was you who did it.

Thank you, Miss Dennis. This has been –

Call me Olive. “Miss Dennis” makes me sound like a schoolteacher again. Though I was a very good schoolteacher. Ten years of it. Not wasted time at all.

But yes. You’re welcome. I’m glad you’ve asked these questions. I’m glad that someone in 2025 is remembering to ask about the work itself, not just the decorative china.

Now, if you’ll excuse me, I have a puzzle that’s been bothering me for weeks, and I’m eager to get back to it. There’s something deeply satisfying about a problem that’s been troubling you, finally yielding to clear thinking.

Letters and emails

Since the publication of this interview, we’ve received dozens of thoughtful letters and emails from engineers, designers, researchers, and students across the globe – all wanting to ask Olive Dennis more about her life, her work, and what guidance she might offer to those following in her path. The questions below represent five voices from our growing community: a researcher in Buenos Aires curious about the evolution of observation-based methods, a mechanical engineer in Berlin wondering how Dennis navigated technical trade-offs and iteration, a UX researcher in Toronto asking about the moment when noticing a problem becomes owning its solution, a transportation systems engineer in Mumbai considering how her principles might apply to contemporary challenges, and a science historian in Addis Ababa posing a profound counterfactual – what if Dennis had documented her methodology for posterity?

These questions honour Dennis’s legacy by taking her seriously as a thinker, not merely as a historical figure. They ask her to engage with modern problems, to explain the reasoning behind her choices, and to reflect on the roads not taken. What follows are five carefully considered inquiries, each grounded in genuine curiosity about the mind and methods of the woman who made comfortable travel possible for millions.

Mariana Cifuentes, 34, Industrial Design Researcher | Buenos Aires, South America
You spent decades measuring passenger comfort empirically – sleeping on mattresses, timing timetable comprehension, observing dining car workflows. But you were working in an era without computers, without statistical software, without the ability to gather data at scale. When you look at how we conduct user research today – with heat maps, eye-tracking, thousands of survey respondents analysed instantly – do you think we’ve genuinely improved on your methods, or have we simply become faster at collecting what you understood through patience and careful observation? And if you had access to modern data tools, would your approach to solving passenger comfort problems fundamentally change, or would you still insist on spending nights on trains, watching how real people actually behave?

Miss Cifuentes, you’ve asked precisely the question I wish more people would ask – not whether I had the right tools, but whether the tools matter as much as the thinking behind them.

You’re correct that I worked without computers, without your heat maps and eye-tracking devices and statistical software that can process thousands of responses in moments. When I tested mattresses, I slept on them – one brand to Chicago, another on the return. When I wanted to know if passengers could read the timetables, I stood in stations and watched them struggle, then I timed how long it took. When I needed to understand dining car flow, I rode in the dining car during service and observed where congestion occurred, where servers had to wait, where passengers hesitated.

Was it slower than your methods? Certainly. But here’s what I want you to consider: speed and volume aren’t the same as understanding.

Your modern tools collect enormous quantities of data very quickly. That’s valuable – I’m not dismissing it. But data collection and comprehension are different activities. You can gather ten thousand survey responses about passenger comfort, but do those responses tell you why a passenger feels uncomfortable? Or do they simply tell you that discomfort exists?

When I rode the trains – and I mean truly rode them, not as an inspector making notes but as someone living the experience – I could see things that no survey would capture. I could see a woman struggling to reach the luggage rack because it was positioned for a man’s height. I could see elderly passengers avoiding the lavatory because the door mechanism was stiff and they were embarrassed to ask for help. I could see a mother trying to warm a bottle for her infant and having nowhere to do it safely. Those observations didn’t come from asking questions. They came from being present, patient, and attentive.

The advantage I had – and I say this with some confidence – was intimacy with the problem. I wasn’t separated from the passengers by a screen or a survey form. I was with them. I experienced what they experienced. When the ventilation failed, I breathed the same ash-filled air. When the seat was uncomfortable, my back ached the same way theirs did. That created a different kind of knowledge.

Now, you ask if I’d change my approach with access to modern tools. Here’s my answer: I’d use them, but I wouldn’t rely on them exclusively. If I could collect data from thousands of passengers instantly, that would help me identify patterns – which complaints were widespread versus which were isolated. That’s useful. But I would still insist on riding the trains myself. I would still sleep in the berths, sit in the seats, eat in the dining cars, struggle with the luggage racks.

Why? Because observation at scale misses the particular. It misses the small detail that, once you see it, unlocks an entire problem. Let me give you an example. In the mid-1920s, I was observing passengers in the women’s dressing room. This wasn’t a formal study – I was simply there, waiting my turn, watching. I noticed that women were reluctant to use the liquid soap dispenser because they couldn’t tell if it was empty without pumping it, and pumping an empty dispenser felt wasteful and foolish. It was a tiny hesitation, barely noticeable. But it told me something important: passengers need visual confirmation that a resource is available before they’ll use it.

Would a survey have captured that? Perhaps, if you’d thought to ask about soap dispensers specifically. But you wouldn’t have thought to ask unless you’d observed the hesitation first. That’s the limitation of data at scale – it answers the questions you know to ask. Observation reveals the questions you didn’t know existed.

I also want to address your question about whether modern methods are genuinely better or simply faster. Here’s what concerns me about speed: it can encourage shallow thinking. If you can test twenty seat designs in a week using VR simulations and user feedback, you might choose the design that scores highest on immediate comfort. But have you tested it over eight hours? Have you tested it when the passenger is tired, when they’ve been sitting for half a day and their body is fatigued? Comfort isn’t a single moment – it’s an experience that unfolds over time. That requires patience to understand.

The tools you have now are powerful, and I’d be foolish to dismiss them. But I’d use them as supplements to direct experience, not replacements for it. I’d gather your heat map data, yes. But then I’d ride the train myself and see if what the data suggests matches what I actually feel. And if there’s a discrepancy – if the data says passengers are comfortable but I observe them shifting constantly, adjusting their position, grimacing slightly – I’d trust the observation over the data.

Because here’s the truth: people don’t always know what they need, and they don’t always report accurately what they’re experiencing. But their bodies don’t lie. Their behaviour doesn’t lie. If you’re present and attentive, you can see the truth they can’t articulate.

So no, I wouldn’t fundamentally change my approach. I’d augment it. I’d be faster at identifying broad patterns. But I’d still spend nights on trains, watching how real people actually behave. That’s where the real work happens.

Rakesh Varma, 47, Transportation Systems Engineer | Mumbai, Asia
You were designing for passenger comfort on long-distance trains, which meant you were thinking about cumulative discomfort – how small irritations compound over eight, twelve, twenty hours of travel. Modern transit design in dense urban environments is very different: people are often on trains for thirty minutes. Does that change what comfort means? And I’m curious about something else: you designed for a specific technology (coal-fired locomotives, Pullman berths, dining car service). We’re now watching autonomous vehicles, hyperloop concepts, and reinvented public transit emerge. If you were entering the field today, how would you approach the observation phase? Would you observe the same way – riding, measuring, sleeping in prototype seats – or would you be tempted by simulation, VR mock-ups, and computational modelling? Where do you think observation has to be physical, and where can it be virtual?

Mr. Varma, you’ve identified something crucial that I hadn’t fully articulated even to myself until this moment: the difference between cumulative discomfort and acute discomfort. Yes, I was designing for journeys that lasted hours, sometimes days. A passenger traveling from Baltimore to Chicago – that’s an overnight journey. Baltimore to St. Louis, longer still. When someone sits in a seat for twelve hours, a pressure point that seems minor in the first hour becomes unbearable by the eighth. A temperature that’s slightly too warm becomes oppressive. A lighting system that’s merely annoying becomes genuinely distressing when you’re trying to sleep.

Your urban transit scenario – thirty minutes – is an entirely different engineering problem. And yes, comfort means something different in that context. For a half-hour journey, a passenger can tolerate a harder seat, less legroom, more crowded conditions. They’re not trying to sleep. They’re not eating a meal. They’re not spending enough time for their body to rebel against poor ergonomics.

But – and here’s where I’d challenge your framing slightly – I don’t think short-duration transit is solely about minimising acute discomfort. There’s something else at work: psychological comfort and predictability. On a thirty-minute journey, what passengers need most is confidence that they’ll arrive on time, that they can easily identify their stop, that they won’t be confused or anxious. That’s a different kind of design problem, but it’s still about the passenger’s experience.

When I redesigned the B&O timetables in the 1920s, I wasn’t thinking about physical comfort. I was thinking about comprehension and anxiety. Passengers couldn’t read the old schedules – they were dense, confusing, formatted in ways that assumed prior knowledge. People would stand at the station, staring at the board, uncertain whether they were reading it correctly. That anxiety, that cognitive load, was a form of discomfort I could engineer away. So I simplified the layout, made the typography clearer, organised information in a way that matched how people actually think about travel – where am I now, where do I want to go, when does the train leave, when does it arrive.

For your urban transit context, I’d apply similar thinking. What creates anxiety on a thirty-minute journey? Missing your stop. Not knowing if you’re on the correct train. Being unable to hear announcements in a crowded, noisy environment. Those are engineering problems with solutions – better signage, clearer route maps, visual systems that don’t depend solely on audio cues.

Now, to your second question about observation methods in an era of simulation and computational modelling. This is where I need to be careful, because I’m speaking about tools I’ve never used. But let me reason through it.

You ask whether I’d be tempted by VR mock-ups and simulation rather than physical observation. Here’s my honest answer: I’d use both, but I’d trust the physical observation more – at least initially – because human bodies respond to real environments in ways that are difficult to simulate accurately.

Let me give you an example from my own work. When I was designing the reclining seat mechanism in the late 1920s, I could have – theoretically – calculated the ideal recline angle based on anatomical measurements and principles of ergonomics. The human spine curves in predictable ways. The angle at which the body relaxes is, to some extent, knowable. But when I actually tested seats at different recline angles on real trains, moving at real speeds, with real vibration and real noise and real passengers who’d been traveling for real hours, I discovered that the theoretically optimal angle wasn’t always the practically comfortable one.

Why? Because comfort on a moving train isn’t just about the angle of your spine. It’s about whether the vibration from the tracks travels up through the seat frame. It’s about whether the recline mechanism creates a pivot point that digs into your lower back. It’s about whether the headrest height works when you’re actually trying to sleep versus when you’re sitting upright. Those variables are extraordinarily difficult to simulate because they interact in complex ways.

So if I were entering the field today, I’d absolutely use your VR and computational tools to eliminate obviously bad designs quickly. Why build ten physical prototypes when you can test them virtually first and narrow it down to three worth building? That’s efficient. But once I had those three candidates, I’d insist on building them physically and testing them in the real environment they’ll be used in – moving vehicles, real passengers, extended time periods.

There’s another consideration: passengers don’t always know what they want or need until they experience it. If you show someone a VR mock-up of a seat and ask if they’d be comfortable in it, they’re imagining comfort. But imagination isn’t experience. I discovered this repeatedly. Passengers would tell me they wanted softer seats – everyone wants soft seats, don’t they? But when I tested genuinely soft upholstery on long journeys, I found passengers became more uncomfortable over time because soft seats don’t provide adequate support. What people said they wanted and what actually served them were different things. Physical observation revealed that discrepancy. I’m not certain simulation would.

However – and I want to be fair to your modern methods – there are aspects of design where simulation might actually be superior to my observational approach. If you’re designing for extreme conditions I couldn’t safely test – very high speeds, emergency scenarios, unusual passenger populations – simulation allows you to explore those spaces without risk. That’s valuable. And if you’re trying to optimise for very large populations with diverse needs, computational modelling can help you identify solutions that serve the widest range of people. I was limited by the passengers I could actually observe. You’re not.

But here’s my concern about relying too heavily on virtual methods: they can create a false sense of certainty. The model says this design will work, so you implement it, and then you discover the model didn’t account for something small but crucial – the way morning sunlight creates glare on a screen, the way a cleaning crew’s disinfectant interacts with certain upholstery materials, the way passengers actually use a space versus how you predicted they’d use it. Physical observation catches those things.

So my approach, if I were starting today, would be this: use simulation and modelling aggressively in early design phases to eliminate bad options quickly. But before final implementation, insist on extended physical testing in real conditions with real users. Build the prototype train car. Run it on actual routes. Observe passengers who don’t know they’re being observed. Ride it yourself for a full day. Sleep in it. Eat in it. Use the facilities. Experience what your design actually does, not what your model predicts it will do.

The tools have changed, Mr. Varma, but human bodies haven’t. We still get uncomfortable in the same ways. We still need the same fundamental things – support, temperature control, adequate space, predictable information, dignity. Those needs don’t change whether you’re traveling for thirty minutes or thirty hours. What changes is which needs become critical first. And the only way to truly understand that priority is to experience the journey yourself.

I’d use your modern tools. But I’d never stop riding the trains.

Anya Petrovic, 41, Mechanical Engineer | Berlin, Germany
Your ventilation patent required balancing three competing demands: stopping coal ash, maintaining air flow, and giving passengers intuitive control. Every engineering decision involved trade-offs. But I’m curious about something you mentioned only briefly – that one early iteration failed because your mesh was too fine. In your era, how did you test and fail without the cost bankrupting a project? What was the relationship between the B&O’s tolerance for “failure” and your ability to iterate? And relatedly, you designed for coal-fired locomotives. When diesel and electric trains arrived, did your ventilation system require redesign, or had you engineered it with enough flexibility to survive that technological shift?

Miss Petrovic, you’ve asked about the economics and politics of failure – the unsexy but absolutely essential question that determines whether good engineering actually happens or remains theoretical. And you’re right to focus on that early prototype where my mesh was too fine. That failure cost money. It cost time. And yes, it required an institutional tolerance for iteration that wasn’t guaranteed.

Here’s the honest answer: I was extraordinarily fortunate in Daniel Willard. The president of the B&O Railroad was a pragmatist, not a romantic, but he understood something crucial – that innovation requires experimentation, and experimentation means some things won’t work the first time. When I proposed the Engineer of Service position in 1921, I didn’t promise him immediate returns. I promised him that I would observe, test, and design improvements that would make passengers more loyal to the B&O. That was the contract: give me authority, give me resources, and I’ll deliver competitive advantage.

But Willard also understood – because he’d come up through the ranks himself, started as a locomotive wiper and worked his way to president – that engineering problems don’t yield to wishful thinking. They yield to methodical testing. So when I came back from that 1925 test run and reported that the ventilator prototype wasn’t working, that the air flow was insufficient, he didn’t terminate the project. He asked what I needed to solve it. More test runs? Different mesh suppliers? Consultation with the engineering department on fluid dynamics? He treated failure as information, not as incompetence.

That said – and I want to be clear about this – I couldn’t fail indefinitely. There was a clock running. The railroad was investing capital in my work. If after two years I hadn’t produced measurable improvements in passenger satisfaction and ridership, the position would have been quietly eliminated. I knew that. So I was strategic about which problems I tackled first.

The ventilator was risky because it required engineering something genuinely new – a mechanism that didn’t exist in the form I needed. But I paired that risky project with lower-risk improvements that I knew would succeed quickly. Redesigning the dressing rooms to include liquid soap and paper towels? That wasn’t technically complex. It was observation plus implementation. Improving the dining car menu based on passenger preferences? That required data collection, not invention. Those early wins bought me credibility. They demonstrated that the position was valuable. That credibility, in turn, gave me room to work on harder problems like the ventilator.

Now, to your question about testing without bankrupting the project: I tested at small scale first. I didn’t immediately install prototype ventilators in fifty passenger cars. I installed them in two cars – one in first class, one in coach – and rode those specific cars repeatedly over several months. I made notes about air flow at different train speeds. I asked passengers – casually, in conversation – whether they noticed any improvement. I measured temperature differentials inside the car. That small-scale testing was relatively inexpensive. When I identified the mesh problem, I could source alternative materials and test again without enormous capital expenditure.

This is where being a woman engineer created an odd advantage. The railroad expected me to be cautious and methodical – those were considered feminine traits, though I’d argue they’re simply good engineering traits. I wasn’t pressured to move quickly or demonstrate masculine decisiveness. I could say, “I need another six months of testing,” and that was accepted as appropriate prudence. A male engineer might have felt pressure to implement faster, to show boldness. I was permitted – perhaps even expected – to be thorough.

The other strategy I used was leveraging competitor research. I rode other railroads constantly – the Pennsylvania, the New York Central, the Southern Railway. When they implemented ventilation systems, I observed them. I noted what worked and what didn’t. That wasn’t theft; that was competitive intelligence. If the Pennsylvania tried a particular mesh configuration and passengers complained about drafts, I didn’t need to test that configuration myself. I’d already learned from their mistake. That saved enormous amounts of testing time and money.

Your second question – about technological shifts from coal to diesel and electric – is fascinating because it gets at design flexibility versus design specificity. The Dennis ventilator was designed to solve a coal-specific problem: cinders and ash. When diesel locomotives began appearing in the 1930s and 1940s, those particulates were much reduced. In theory, the ventilator became less necessary.

But here’s what actually happened: passengers liked having personal climate control. They’d become accustomed to it. Even without coal ash, they wanted to control fresh air flow. So the ventilator’s original purpose – filtering particulates – became secondary to its user-facing function – giving individual passengers agency over their environment. That meant the mechanism itself didn’t require fundamental redesign. The fine mesh could be replaced with coarser mesh or even eliminated in diesel-era cars, but the control system – the hinged lid, the cam and roller mechanism, the intuitive pull-down operation – remained valuable.

This taught me something important about engineering for human needs: solve for the human first, and the technology second. I designed a system that gave passengers control. The fact that it also filtered coal ash was almost incidental. Once passengers had experienced personal control over ventilation, they didn’t want to give it up, regardless of whether the air needed filtering. That’s why the system survived the technological transition.

However, I’ll be honest – I didn’t foresee that completely. I designed for coal because coal was the reality of 1926. The flexibility you’re asking about wasn’t conscious future-proofing; it was fortunate consequence. If I were designing today, I’d think more deliberately about technological transitions. I’d ask: what’s the underlying human need, independent of current technology? Design for that need, and the specific technology becomes interchangeable.

One more thing, Miss Petrovic, because you asked about the relationship between tolerance for failure and ability to iterate: the B&O’s tolerance wasn’t infinite, but it was greater than most railroads because Willard had positioned passenger service as a strategic competitive advantage. We were competing with automobiles – this was the 1920s and 1930s, and American families were buying cars, choosing to drive rather than take trains for medium-distance travel. Willard understood that if the B&O couldn’t offer something automobiles couldn’t – comfort, convenience, amenities – we’d lose passengers permanently.

That competitive pressure created space for my work. When I asked for time to test another ventilator prototype, I could frame it as: “The Pennsylvania Railroad doesn’t have this. If we perfect it, we have a competitive advantage that distinguishes B&O passenger service.” That argument worked. It worked because it was true, but also because Willard was already primed to believe that passenger experience improvements were worth the investment.

Not every engineer has that luxury. Many work for organisations that view failure as waste rather than information. That’s a tragedy, because genuine innovation requires the freedom to be wrong on the way to being right. I was fortunate. But I also earned that fortune by delivering results consistently enough that my occasional failures were tolerated as the cost of doing ambitious work.

Mulugeta Tesfaye, 38, Science Historian & Policy Advocate | Addis Ababa, Africa
This is speculative, but I think it matters: What if you had written extensively? What if you’d published papers on service engineering, documented your methodology, created a theoretical framework that other engineers could build on? You mentioned you were too embedded in the work to step back and theorise. But imagine you hadn’t been. Imagine that instead of designing The Cincinnatian, you’d spent that time writing a textbook on passenger-centred engineering. How might the field of engineering itself have evolved differently? Would service design have emerged as a recognised discipline fifty years earlier? Would women in technical fields have had a documented body of work by a woman engineer to reference and build upon? In other words: do you think your invisibility in the historical record was simply bad luck, or was it partially a consequence of your choice to do the work rather than document it?

Mr. Tesfaye, you’ve asked the question that haunts me most at this distance. Not “what did you accomplish?” – I know what I accomplished. But “what didn’t you do that might have mattered more?” That’s the harder question. And you’re asking it as a historian, which means you understand that individual choices ripple outward in ways we can’t always predict.

So let me answer honestly: yes, my invisibility in the historical record was partially a consequence of choosing to do the work rather than document it. But it wasn’t simply bad luck either. It was a series of calculated decisions that made sense at the time and that I now see differently.

Here’s the truth: I could have written. I had the training – a master’s degree in mathematics from Columbia, a Cornell engineering degree. I could have published papers in engineering journals. The American Railway Engineering Association would have accepted submissions from me; I was a member in good standing from 1923 onward. I could have presented at conferences – and I did speak occasionally, but informally, to women’s groups and passenger service organisations, not at major engineering conferences where the work would have been documented and cited.

Why didn’t I? Several reasons, and I need to be honest about all of them, not just the flattering ones.

First, I was embedded in proprietary work. Everything I designed belonged to the B&O Railroad. If I’d published detailed technical papers about the ventilator mechanism, I’d have been giving away competitive advantage to other railroads. The B&O wouldn’t have forbidden it outright – they weren’t cruel – but there would have been pressure not to share too much. And I was loyal to the railroad. They’d given me an extraordinary opportunity. Publishing felt, at the time, like a betrayal of that trust.

But here’s what I didn’t fully grasp: I could have published about methodology without revealing proprietary details. I could have written about the process of service engineering – how to observe passengers, how to design experiments, how to balance competing demands, how to think about cumulative comfort versus acute discomfort. That wouldn’t have given away trade secrets. That would have established a framework other engineers could learn from. I didn’t do that because I didn’t think in those terms. I thought in terms of solving problems, not in terms of building a discipline.

Second – and this is harder to admit – I didn’t believe my work would be taken seriously in academic or professional publications. Not because it wasn’t rigorous, but because it was about comfort, about passenger experience, about what were considered “soft” concerns. The engineering journals published papers about bridge load calculations, rail bed materials, locomotive efficiency – hard, measurable, traditionally masculine concerns. A paper about mattress selection or soap dispenser placement? I genuinely wasn’t sure it would be published. And I was afraid of the rejection, afraid of having my work dismissed as domestic trivia dressed up as engineering.

Looking back, I was probably wrong about that. There were engineers who would have recognised the value of the work. But I let fear and assumption prevent me from trying. That was my failure, not the profession’s.

Third, as I mentioned in our earlier conversation, I was focused on immediate implementation. I could see passengers using the improvements I designed. That feedback loop was powerful and satisfying. Writing for publication felt abstract by comparison – sending words out into the world, hoping someone somewhere might read them and find them useful someday. Versus installing reclining seats and watching passengers relax into them immediately. The tangible work won. Every time.

But now, from this vantage point, I can see what I sacrificed by making that choice. If I had written a textbook on service engineering in, say, 1935 – midway through my career, when I’d accumulated substantial experience but still had years of work ahead – what might have happened?

Airlines were just beginning commercial passenger service in the 1930s. They were making the same mistakes railroads had made decades earlier – uncomfortable seats, poor ventilation, no thought given to passenger experience beyond basic transportation. If there had been a documented body of knowledge about passenger-centered design, airline engineers could have learned from it. They could have avoided repeating our errors. Instead, they had to discover everything themselves, slowly, expensively.

Service design as a formal discipline might have emerged in the 1940s rather than the 1980s. Imagine if ergonomics and human factors engineering had been established fields fifty years earlier, with a woman engineer as a founding figure. How might that have changed which problems got attention, which design questions were considered legitimate, which voices were heard?

And here’s the part that troubles me most: future women engineers would have had a reference point. When I was starting out, I had no examples. There were no women engineers whose work I could study, whose careers I could learn from, whose methodologies I could adapt. I was inventing everything as I went along – not just the technical solutions, but how to be a woman engineer in a male profession. If I had documented that journey, if I had written honestly about the challenges and strategies, perhaps the women who came after me wouldn’t have had to reinvent everything themselves.

So yes, Mr. Tesfaye, I think my invisibility was partly my own doing. I chose immediacy over documentation. I chose loyalty to my employer over building an independent professional reputation. I chose the satisfaction of solving problems over the slower, more abstract work of teaching others how to solve problems.

Were those bad choices? Not entirely. The work I did mattered. Millions of passengers benefited from it. But they were incomplete choices. I could have done both – designed the trains and documented the methodology. It would have required more time, more energy, more confidence in the value of my own thinking. But it was possible.

Here’s what I should have done: I should have kept detailed notebooks, not just sketches and measurements, but reflective writing about why I made certain decisions, what alternatives I considered, what I learned from failures. Those notebooks wouldn’t have needed to be published immediately. But they would have existed as a record. And when I retired in 1951, I could have worked with someone – a younger engineer, a historian, a technical writer – to turn those notebooks into something publishable.

I didn’t do that. I kept sketches and technical drawings, yes. But I didn’t document my reasoning, my process, my methodology. And as a result, what survived in the historical record were the visible artifacts – the china pattern, the Cincinnatian train – not the thinking that produced them.

You ask how the field might have evolved differently if I’d written that textbook. Here’s what I imagine: Service engineering would be a recognised specialisation within civil and industrial engineering by the 1950s. Universities would teach it. There would be established principles, documented methodologies, a body of peer-reviewed research. Women engineers would have a clear precedent – not just “a woman managed to work in engineering despite barriers,” but “a woman founded an entire subfield and established its intellectual foundations.”

And perhaps most importantly, the devaluation of “soft” engineering – ergonomics, human factors, user experience – might have been reduced. If service engineering had academic legitimacy early on, if it had a founder whose technical credentials were unimpeachable, then the gendered dismissal of that work as “housekeeping” or “decoration” would have been harder to maintain.

But I didn’t write that textbook. I did the work, and the work mattered, but I didn’t create the intellectual infrastructure that would have allowed the work to grow beyond me. That’s my regret. Not bitterness – I’m too old for bitterness – but genuine regret. I could have done more. I should have done more.

The question for your generation, Mr. Tesfaye, is whether you’ll learn from my mistake. Do the work, yes. But also document it. Write it down. Publish it. Teach it. Build the structures that allow your work to outlive you and influence people you’ll never meet. Don’t assume someone else will do that for you. They won’t. If you don’t claim your own intellectual legacy, it will disappear.

I learned that too late. You don’t have to.

Lila Montgomery, 29, UX Researcher | Toronto, North America
This question is about something you touched on but didn’t fully explore: the moment when your observation of a problem became the decision that it was your problem to solve. You could have noted that women passengers wanted better dressing rooms and reported it to someone else. Instead, you designed the dressing rooms yourself. You could have observed that passengers were confused by timetables and suggested someone else redesign them. Instead, you redesigned them. What made you decide that observation should lead to ownership? Was there ever a moment when you thought, “This isn’t my responsibility,” and how did you move past that? Because that threshold – between noticing a problem and claiming the authority to solve it – seems critical for women in technical fields, and I’m not sure it’s taught anywhere.

Miss Montgomery, you’ve identified the exact threshold that determines whether someone becomes an engineer or remains an observer. And you’re right that it’s not taught anywhere – at least, it wasn’t in my time, and I suspect it still isn’t in yours. Because what you’re asking about isn’t a technical skill. It’s a form of authority that you have to claim for yourself, often without permission, and sometimes in the face of active opposition.

Let me tell you when I first crossed that threshold, because I remember it vividly.

It was 1921, early in my tenure as Engineer of Service. I was riding a train from Baltimore to Pittsburgh, observing the women’s dressing room during evening hours when passengers were preparing for bed. The room was cramped – barely six feet by four feet – and there was a constant queue of women waiting outside. I watched women apologise to each other for taking too long, watched them struggle to manoeuvre in the tiny space, watched elderly women nearly lose their balance when the train lurched.

I made notes. That was my job – observe and report. And my initial instinct was exactly what you described: I would document this problem and present it to someone who would then decide what to do about it. The engineering department, perhaps. Or the passenger service committee. Someone with actual authority.

But then I thought: who knows more about this problem than I do right now? I’ve been watching it for three hours. I’ve measured the space. I’ve observed fifteen different women struggling with it. I understand exactly what’s wrong and why it matters. If I hand this to someone else, they’ll have to start from the beginning – ride the trains, observe passengers, reach the same conclusions I’ve already reached. That’s inefficient. Worse, they might not reach the same conclusions because they won’t see what I’m seeing.

So I made a decision. I didn’t ask permission. I went back to Baltimore and I drafted a redesign of the women’s dressing room. I specified dimensions. I identified which wall could be moved – there was dead space on the other side that served no function. I calculated the cost of the modification. I designed a new fixture layout that would give passengers more room to manoeuvre. And then I presented it not as a problem requiring someone else’s solution, but as a solution requiring approval for implementation.

Daniel Willard looked at my proposal and said, “Is this necessary?” And I said, “Yes.” Not “I think so” or “Perhaps we should consider it.” Just yes. And then I explained why, using the observations I’d made, the measurements I’d taken, the cost-benefit analysis I’d calculated. He approved it.

That was the moment I crossed the threshold. I stopped being someone who noticed problems and became someone who solved them.

But here’s what made that possible, and I want to be very clear about this because it matters for you and for every woman engineer reading this: I had institutional backing. Willard had created the Engineer of Service position and given me authority to improve passenger experience. When I claimed the authority to redesign the dressing rooms, I wasn’t acting in defiance of the organisation – I was acting within the mandate I’d been given. That’s a crucial distinction.

Many women don’t have that backing. They’re hired as junior engineers, as assistants, as drafters. They notice problems constantly – because women engineers often see things male engineers overlook – but they don’t have the institutional authority to claim ownership of solutions. If they try, they’re told they’re overstepping, being presumptuous, not staying in their lane.

So how do you claim authority when you don’t have institutional backing? This is harder, and I’m not sure I have a perfect answer because my circumstances were unusual. But here’s what I observed in my own career and in watching other women navigate similar situations:

First, you build credibility by solving small problems perfectly. When I started at the B&O, I didn’t immediately propose redesigning entire passenger cars. I noticed that the dining car menu was confusing, and I rewrote it to be clearer. Small change, immediate improvement, no controversy. That success gave me credibility for the next, slightly larger proposal. Each success built on the previous one. After several years of this, I had enough accumulated credibility that when I proposed something ambitious – like the ventilator system – people trusted that I knew what I was doing.

Second, you frame your solutions in terms the organisation already cares about. I never said, “Women passengers deserve better dressing rooms because it’s the right thing to do.” I said, “Women represent half our ridership and a significant portion of our revenue. If we make their experience more comfortable, they’ll choose B&O over competitors, and our passenger numbers will increase.” That was a business argument, and Willard was a businessman. I was asking him to invest in passenger loyalty, not to be charitable to women. That framing worked because it aligned with what he already valued.

Third – and this is the hardest part – you act as though you have authority even when you’re not certain you do. When I presented that dressing room redesign, I had no explicit permission to design dressing rooms. My title was Engineer of Service, which was vague enough to mean almost anything. I interpreted it broadly. I claimed the authority to design anything that affected passenger service. And because I claimed it confidently, without apology, it was accepted.

But I need to be honest about something: this strategy works better for some people than others. I was a white woman with advanced degrees from prestigious universities, working for a major corporation that had decided to invest in passenger comfort. I had class privilege. I had educational privilege. I had institutional backing, even if it was sometimes ambiguous. A woman without those advantages – a woman of colour, a woman from a less prestigious educational background, a woman working in a less progressive organisation – would face much greater resistance using the same strategies.

That doesn’t mean the strategies are worthless. It means they’re incomplete. They work, but they work more reliably for women who already have some form of privilege or institutional support. And we need to be honest about that rather than pretending that confidence alone is sufficient.

Now, you asked specifically about the moment when observation becomes ownership – when you move from “I notice this problem” to “This is my problem to solve.” Here’s what I learned: that moment has to be intentional. It doesn’t just happen. You have to decide that you’re claiming it.

And here’s the secret: you don’t have to wait until you’re certain you have the authority. You can act first and seek approval afterward. That’s what I did with the dressing rooms. I designed the solution before asking permission to design it. By the time I presented it to Willard, the intellectual work was done. He could approve it or reject it, but he couldn’t take away the fact that I’d done the thinking, the calculation, the design work. That work was mine.

Sometimes it’s easier to ask forgiveness than permission. If you wait for someone to explicitly tell you, “Yes, you have authority to solve this problem,” you might wait forever. But if you solve it first – competently, thoroughly, with clear reasoning and documentation – it becomes much harder for anyone to say you shouldn’t have done it. The solution exists. The question becomes whether to implement it, not whether you had the right to think about it.

But – and this is important – you have to be willing to accept the consequences if your gambit fails. If I’d presented that dressing room redesign and Willard had said, “This isn’t your job, stay in your lane,” I would have needed to accept that. The strategy of claiming authority without explicit permission only works if you’re genuinely prepared for the possibility that the organisation will reject your claim. You can’t be devastated by that rejection. You have to treat it as information – “All right, this organisation isn’t ready for me to work at this level” – and either continue building credibility until they are ready, or find an organisation that is.

Here’s my final thought on this, Miss Montgomery: the threshold you’re asking about is fundamentally about self-perception. As long as you see yourself as someone who notices problems and reports them to others, that’s what you’ll be. The moment you see yourself as someone who solves problems – who has the capability, the training, the insight to design solutions – you’ll start acting differently. You’ll stop writing reports that say “Someone should fix this” and start writing proposals that say “Here’s how I would fix this.”

That shift in self-perception is terrifying because it requires claiming expertise you’re not sure you have. But here’s the truth: you have more expertise than you think. You’ve observed the problem. You understand its dimensions. You’ve been trained in engineering principles. You can reason through solutions. The only thing stopping you from designing that solution is the belief that it’s not your job to do so.

Make it your job. Claim it. And if someone tells you it’s not your place, ask them: “Then whose place is it? Who knows this problem better than I do right now?” Often, there’s no good answer to that question. And in that silence, you’ll find your authority.

Reflection

Olive Wetzel Dennis died on November 5, 1957, in Baltimore, Maryland. She was seventy-one years old. The obituaries noted her work with the Baltimore & Ohio Railroad, mentioned the china pattern that had become iconic, and briefly acknowledged her engineering credentials. What they largely missed – what the historical record has continued to miss – was the scope of what she’d actually built: not just ventilation systems and reclining seats, but an entire methodology for thinking about how people experience the world they move through.

Throughout this conversation, certain themes emerged with absolute clarity. Dennis spoke repeatedly about the act of claiming authority – not waiting for permission, but choosing to own problems and their solutions. She reflected on the economics of failure, acknowledging how institutional backing from B&O president Daniel Willard gave her room to iterate and test, a luxury many engineers never receive. She was candid about her regret at not documenting her methodology, recognising that her choice to prioritise immediate implementation over written scholarship contributed to her erasure from the historical record. These admissions – particularly her willingness to acknowledge what she might have done differently – diverge from the sanitised heroic narratives often constructed around historical figures. The Olive Dennis of this interview is neither victim nor saint. She’s a pragmatist who made calculated choices, benefited from certain privileges, and now sees clearly what those choices cost.

Where this imagined Dennis perhaps differs most sharply from recorded accounts is in her explicit critique of how her work was received. Contemporary newspaper coverage framed her as “the world’s greatest housekeeper,” emphasising the decorative and domestic aspects of her role. In this conversation, Dennis pushes back forcefully against that reduction, insisting that passenger comfort is engineering – that ergonomics, ventilation, materials science, and human factors research are technically sophisticated disciplines. This insistence feels consistent with who she was, but whether the historical Dennis would have articulated it with such clarity remains uncertain. The archival record is frustratingly sparse. We have her patents, her china, restored train cars at the B&O Railroad Museum. We have brief mentions in engineering association records. But we don’t have her reflective writing, her personal correspondence about professional struggles, her private thoughts on being the only woman in countless rooms of men.

What’s certain is that Dennis’s innovations are everywhere today. Every reclining airline seat traces conceptually to her 1920s rail designs. Every personal air vent, every dimmable cabin light, every accessible lavatory reflects principles she established. Yet until recently, her name appeared in few design history texts. The Smithsonian’s exhibits on transportation occasionally mentioned her china but overlooked her ventilation patents. It wasn’t until the 2010s – more than fifty years after her death – that scholars like those at the Maryland Women’s Heritage Centre began seriously documenting her technical contributions. Engineers at Cornell, her alma mater, now cite her as a founder of user-centred design, though that recognition arrived generations too late.

The questions posed by our international community – from Buenos Aires, Berlin, Toronto, Mumbai, Addis Ababa – revealed something essential: Dennis’s work remains urgent. Mariana Cifuentes asked whether modern data collection tools have genuinely improved on Dennis’s patient observation methods, or whether we’ve simply become faster at gathering information we don’t fully understand. Rakesh Varma wondered how her principles apply to contemporary urban transit, where journeys last thirty minutes rather than twelve hours. Anya Petrovic probed the institutional tolerance for failure that made Dennis’s iterative design process possible. Mulugeta Tesfaye asked the hardest question: what if Dennis had written extensively, creating intellectual infrastructure for service engineering as a discipline? And Lila Montgomery identified the precise threshold where observation becomes ownership – the moment when a woman engineer stops reporting problems and starts solving them.

Dennis’s story illuminates what we’ve gained and what remains unfinished. Women comprise roughly sixteen percent of civil engineers in the UK and seventeen percent in the US – barely higher than Dennis’s era. The “leaky pipeline” persists: women enter engineering but don’t stay, driven out by lack of credit, gendered devaluation of their work, and isolation. The fields Dennis pioneered – ergonomics, human factors, service design – remain undervalued compared to “hard” engineering disciplines, still coded as feminine and therefore lesser. Her experience of signing away patents and watching her name disappear from innovations echoes in contemporary debates about intellectual property, employment agreements, and who gets remembered.

But there’s also progress. Service design is now a recognised profession commanding substantial salaries. User experience research draws directly on methodologies Dennis invented. Engineering programmes increasingly teach human-centred design. And crucially, women engineers today have examples – imperfect, incomplete, but real – of women who came before. Dennis is one of those examples, finally receiving the recognition she earned but never fully claimed.

For young women entering STEM fields today, Dennis offers both inspiration and warning. She proved that women can engineer anything if given the opportunity. But she also demonstrated that doing brilliant work isn’t sufficient if you don’t insist on being seen doing it. Her advice – demand credit, document your methodology, build intellectual infrastructure that outlives you – carries weight precisely because it comes from someone who didn’t do those things and now sees the cost.

Perhaps Dennis’s most profound legacy isn’t any single invention but rather her fundamental insight: that engineering isn’t only about structures and systems, but about human beings moving through the world, trying to be comfortable, trying to get where they’re going with dignity intact. Every time you recline your seat, adjust your air vent, or navigate a well-designed space, you’re benefiting from that insight. You’re living inside Olive Dennis’s mind, whether you know her name or not.

The question – for engineers, designers, historians, and all of us who inherit the infrastructure she built – is whether we’ll let her remain invisible or finally give her the visibility she earned. This conversation is one small attempt at correction, one imagined dialogue that insists: her name matters, her thinking matters, and the world she helped create deserves to know who made it possible.

Who have we missed?

This series is all about recovering the voices history left behind – and I’d love your help finding the next one. If there’s a woman in STEM you think deserves to be interviewed in this way – whether a forgotten inventor, unsung technician, or overlooked researcher – please share her story.

Email me at voxmeditantis@gmail.com or leave a comment below with your suggestion – even just a name is a great start. Let’s keep uncovering the women who shaped science and innovation, one conversation at a time.

Editorial Note

This interview is a work of informed imagination. Olive Wetzel Dennis died on 5th November 1957, and cannot speak for herself. We’ve presented a dramatised reconstruction – a carefully researched portrayal of how she might have reflected on her life, work, and legacy if given the opportunity to do so today.

The factual foundation is solid. Dennis’s patents are documented; her role at the B&O Railroad is verified; her innovations – reclining seats, ventilation systems, air-conditioned trains, ergonomic design – are well-established in transportation history. Her birth year (1885), her education at Cornell, her position as the first female member of the American Railway Engineering Association, and her retirement in 1951 are all matters of historical record. The china pattern she designed for the 1927 centennial celebration remains on display at the B&O Railroad Museum.

However, the words attributed to Dennis in this interview are invented. We do not have extensive recorded interviews with her reflecting on her career, her methodology, or her regrets. The quotes attributed to her here – her descriptions of testing mattresses, her analysis of the ventilator’s technical challenges, her candid acknowledgment of what she wished she’d done differently – are interpretations based on scattered archival evidence, patent documentation, and historical accounts, but they are not her documented words.

The supplementary questions from international contributors are entirely fictional, designed to explore themes and tensions in Dennis’s legacy rather than to represent actual correspondence.

This reconstruction honours Dennis by taking her seriously as a thinker and engineer, allowing her to articulate the complexity of her experience rather than reducing her to a flat historical fact. It also respects readers by being transparent: this is how one might imagine Dennis would speak if she could, based on what we know of her work and the evidence of her times. It is not a transcript. It is a dialogue with history – one designed to illuminate her contributions whilst acknowledging the limits of what we can definitively know about her inner life and reflections.

The goal is to make visible what historical erasure has obscured, whilst maintaining intellectual honesty about the distinction between documented fact and informed reconstruction. Dennis’s innovations speak for themselves. This interview simply gives them voice.

Bob Lynn | © 2025 Vox Meditantis. All rights reserved.