The Development of the Steam Engine

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Podcast Transcript

The industrial revolution began the biggest change to humanity since the dawn of agriculture.  

The start of the industrial revolution is largely considered to have begun with the invention of the steam engine. A device that could convert heat to mechanical work. 

Yet, the steam engine wasn’t developed all at once. It was an invention that has its roots over 2000 years in the past. 

Learn more about the steam engine and how it was developed, on this episode of Everything Everywhere Daily.

It is a common thread in many of my episodes that things we think of as being recent inventions have their origins far earlier than most people realize. 

This is most definitely true for the steam engine.

The concept behind a steam engine is pretty simple. You boil water using some sort of heat source, which was usually wood or coal in the early industrial revolution. The water then turns into steam which is a hot gas. Because of its high temperature, this gas then exerts a pressure that can be used to do work. This pressure can then spin a turbine or lift a piston, which in turn can be harnessed to turn a wheel or a gear to produce mechanical work. 

It is perhaps a gross simplification, but I think it captures the spirit of what a simple steam engine does. 

The first documented case of using hot steam to create mechanical motion dates back 2000 years to the first century. 

An early engineer by the name of Hero of Alexandria, who taught at the Musaeum of Alexandria, built a device that was called an aeolipile. 

An aeolipile is a pretty simple device. It is a sphere with nozzles bent in opposite directions sticking out, with the sphere attached to an axel to allow it to spin.

When heated, the steam would shoot out the nozzles, causing the entire device to rotate rapidly. 

While Hero is often credited as the inventor the aeolipile, he probably didn’t create the first one. The Roman architect Vitruvius had mentioned an aeolipile a few decades earlier, and that was probably based on the work done by an Alexandrian Greek by the name of Ctesibius as early as 200 years before that. 

So, people knew very early on that you could do stuff with steam. 

The thing is, they didn’t really do anything with the aeolipile. As far as we can tell, it was basically a party trick. 

The evidence of the aeolipile so long before the development of the steam engine has for centuries made people wonder why it took so long to develop the steam engine, and if the industrial revolution couldn’t have occurred centuries sooner. 

This may be the subject of a future episode, but it is really interesting to think about. Imagine if steam-powered factories and locomotives existed in Ancient Rome or China. 

As interesting of an idea as it might be, the fact is it didn’t happen. It would be more than 1,500 years from Hero of Alexandria’s aeolipile to the first practical steam engine. 

During that time other people certainly considered what steam could do. Leonardo Da Vinci wrote about an idea for steam-powered cannon. The Ottoman scholar Taqi al-Din came up with an idea for a steam-powered rotary wheel, which could be used as a water wheel. 

The thing which started us down the path to steam was, of all things, a pressure cooker. In 1679, the French scientist Denis Papin created what he called a steam digester that could extract fat from bones. One of the novel innovations he added was a release valve, as several early prototypes exploded. 

Explosions are a hazard of working with pressurized steam. 

Papin also developed a pressurized cylinder that when cooled could create a vacuum, and that could be used to pull weights. 

The steam digester wasn’t an engine and, Papin’s other ideas never were put to practical use, but Papin’s ideas did provide the inspiration for something that did. 

The English engineer Thomas Savery developed the first thing that could be called a steam engine in 1698. 

The problem he was working on was an ancient one that had vexed people for centuries: flooding in mines. 

If you did deep enough, most mines will eventually fill up with water. Below the water table, waters will seep through the cracks and eventually flood a mine shaft. 

Hand pumps could only lift water so far. If you went beyond that limit, you were out of luck. 

Savery’s pump didn’t actually use steam pressure to do work. It did just the opposite. It would fill a container with hot steam, then shower the outside with cold water, which would cause the steam to condense, creating a vacuum. The vacuum would then suck up water, causing it to rise and fill up the container. 

The Savery pump had two chambers, when one was being filled with water, the other was being heated, and vice versa. 

The Savery pump was a huge breakthrough in the use of steam, but it wasn’t very efficient, and it didn’t create motion. It couldn’t move a piston or a crankshaft, it just moved water. 

The next innovation was also developed with the intent of pumping water out of mines. In 1712, an English blacksmith by the name of Thomas Newcomen developed what was called the atmospheric steam engine. 

Like the Savery pump, it would fill up a cylinder with hot steam, and then cold water was sprayed on it to condense the steam and create a vacuum. Unlike the Savery pump, that vacuum would then cause atmospheric pressure to push down a piston to fill the cylinder. 

Steam would then fill up the cylinder again, pushing the piston out, and then the cycle would repeat. 

The Newcomen engine was better than the Savery pump, but it was still incredibly inefficient. For starters, it allowed steam to escape, which was a huge loss of energy. 

The next big leap came from a Scottish engineer by the name of James Watt. Watt studied at the University of Glasgow where he was introduced to the ideas of steam power. 

In 1765, he was asked to repair a Newcomen engine when he came up with an idea of an engine that would be radically more efficient. Watt estimated that a full 80% of the energy in a Newcomen steam engine was wasted reheating the cylinder over and over.  

Watt developed an engine with a separate condenser chamber that was connected to the hot cylinder. Different valves would open depending on where the piston was in the cycle, allowing steam to escape to be condensed in the cooler condenser.

Unlike Savery and Newcomen who built their devices to solve a particular problem, Watt created a full-on start-up company with venture capital to create a general steam engine…. although they wouldn’t have used those terms at the time. He and his business partner Matthew Boulton created the Boulton and Watt Company. 

Watt worked on many incremental improvements for the next decade, and there were many that needed to be made. For example, creating a perfectly round cylinder and piston to fit in it was very difficult given the state of metallurgy at the time. There needed to be a good seal for the piston so steam wouldn’t escape. 

Finally, in 1776, his engine was available for sale. 

The Watt engine was a smash hit. It could do so much more than just pump water. It could be used for a wide variety of applications, and the Watt engine was purchased by mills and factories. 

The Watt engine, however, was still using the power of a vacuum via the condensation of steam, and atmospheric pressure to drive a piston. 

More power could potentially be created by using high-pressure steam. 

High-pressure steam power had many benefits and one huge drawback. 

A high-pressure steam engine could be built much smaller and cheaper than an atmospheric engine. Because it was smaller, it could be used to move itself, opening up the possibility of steam-powered transportation. It also could operate at much higher cycles, which was necessary for the operation of many machines. 

The big downside was that they could blow up. 

Boulton and Watt used their patents to block the development of high-pressure steam engines for years as Watt thought they were too dangerous. 

The first high-pressure steam engine was developed by the British inventor Richard Trevithick in 1800, and he used it to demonstrate the first steam locomotive in 1804. 

The first commercial high-pressure steam engines were manufactured by the American Oliver Evans in 1811. The primary market for his engines was on riverboats on the Mississippi River. 

I should note that the first steamboat, which was created by American inventor Robert Fulton in 1807, actually used a Watt atmospheric engine. 

The difference between Evans’ engine and Watt’s is that the Watt engine would operate at a maximum pressure of 7-9 pounds per square inch, which is considered low pressure. The Evans engine would operate as high as 50 psi. 

There was still lots more room for improvement. American George Henry Corliss developed the Corliss Engine in 1849 which offered a 30% improvement over all previous steam engines. It used separate valves for exhaust and for steam, which meant reduced changes in temperature, and it also had vastly improved valves as well. 

Throughout the 19th century, steam engines kept operating with higher and higher pressures, which offered more and more power. The danger of operating at pressures this high never went away. 

If you remember way back to my episode on The Sultana Steamboat Disaster, in 1865, 1800 people were killed on a steamship when the boiler exploded. There were many other such disasters that occurred wherever you had high-pressure boilers. 

These explosions began occurring more frequently in the early 20th century. Between 1905 and 1911, 1300 people were killed in just the United States from boiler explosions.  Pressures inside the boilers were reaching levels over 300 psi by this time. 

In 1915 the American Society of Mechanical Engineers issued guidelines for working with high pressure, which lead to the development of improved safety release valves that would automatically release steam if pressure rose beyond a critical level. 

Steam power was used in the 19th century for transportation and for operating machinery. Beginning in the 1880s a whole new avenue opened up for steam power. The production of electricity. 

In 1884, American Charles Parsons created a steam-powered turbine that would turn an electric dynamo. 

Steam turbines turned out to be much easier to scale up than steam engines did. 

Parsons’ first turbine was a reaction turbine. In a reaction turbine, the steam literally escapes through nozzles, just like the ancient aeolipile. 

These were later replaced by what is known as impulse turbines. In an impulse turbine, the hot stream of steam is pass through fan blades, similar to a jet engine.

This is still used today in most coal, gas, geothermal, concentrated solar, or nuclear power plants which use steam to create electricity. About 80% of the electricity in the world today is driven by steam-powered turbines. 

Eventually, the direct use of steam power was replaced by internal combustion engines, or by turbo-electric systems. 

In a turbo-electric system, instead of the steam being used to create mechanical power directly, the steam is just used to create electricity via a turbine, and then the electricity is used via electric motors to do mechanical work. 

While there are many steam turbines in use today, primarily for electrical generation, there are very few steam engines in operation. 

There is actually one still in use in the Netherlands, but it isn’t used that often.  The Wouda Pumping Station in Friesland was built to pump excess water out of the low-lying Dutch region. It was opened in 1920 and it is still in operation. In fact, it was named a UNESCO World Heritage Site. 

They have modern pumps as well, but if the water level is too high, they will fire up the 100-year-old steam pump to help out. When I visited, they actually turned it on and it was quite the experience. It is the largest steam pump still operating in the world today. 

While there aren’t many steam engines anymore, they played a pivotal role in the development of the modern world. Mechanized factories, locomotives, and all the technical innovations that followed wouldn’t have been possible if it wasn’t for the development of steam engines. 


The executive producer is Darcy Adams.

The associate producers are Thor Thomsen and Peter Bennett.

Today’s review comes from listener Duke of Duramax over at Apple Podcasts in the United States. They write, 

Awesome show.

I am not one to listen to podcasts but I thought I give it shot now that I work for myself. I started looking for historical and fact-based ones. I came across your podcast. I got hooked. I listened to all your episodes on Pandora. I like how easy it is for me to keep up when I’m short on time, so this helps keeps me on my toes. I love how you do a little bit of everything, which also helps me with my mind so that I have to think of so many different types of facts at once. 

I don’t think I have a favorite episode as they are all my favorite. I hope you keep making episodes. Thanks for keeping me company on my work days. From your Minnesota history friend. 

P.S. I hope you make an episode about Rudolf Diesel.

Thanks, Duke of Duramax! I think an episode about Rudolf Diesel and the engine and fuel named after him, and his mysterious death, is certainly something I could do. I have added it to the ever-expanding list of show ideas. 

Remember, if you leave a review or send me a boostagram, you too can have it read the show.