Both steam engines and cannons involve making a metal cylinder strong enough to manage high-pressure gases pushing an object through the cylinder. A cannon push a cannonball through the barrel, while a steam engine push a piston through the cylinder. However, both deal with the same set of problems:

1. How do you make a straight smooth bore to allow a ball, bullet, or piston to move through with minimal friction and tight fit?

2. How do you make sure the cylinder or barrel is strong enough to not burst from the high pressure?

In a steam engine, the piston is moved using hot high-pressure steam, while a gun or cannon moves the projectile through the barrel using the hot gases produced when gunpowder is ignited. It may surprise you that the first engines made were in fact gunpowder driven and not gasoline or steam driven.

Why am I bringing up this point in a story about why China did not invent the steam engine? Because mastery of cannon making was very much a prerequisite technology for the development of the steam engine. One of the hardest problems James Watt faced when building his steam engine was to create a perfect cylinder. If the cylinder isn’t perfectly smooth and straight, you will get gas leakage and dramatically reduce the efficiency and practicality of the engine. From wikipedia:

The principal difficulty was in machining the piston and cylinder. Ironworkers of the day were more like blacksmiths than modern machinists, and were unable to produce the components with sufficient precision.

James Watt never managed to solve this problem alone, instead he was entirely dependent on the help of John “Iron-Mad” Wilkinson, who had developed precision boring techniques for cannon making. Thus, without highly evolved cannon foundries, the Steam Engine could not have been realized.

Consequently, to understand why Europeans and not the Chinese invented the Steam Engine, we have to look at what caused Europe to develop significantly more advanced gunpowder weapons.

What is puzzling about the European dominance in making gunpowder weapons is that it was a Chinese invention. A popular meme on the internet is that the Chinese did not develop gunpowder weapons because they were so peaceful compared to Europeans. All they cared about was pretty fireworks. That is patently false. The Chinese did, in fact, actively use gunpowder weapons in warfare, yet the technology advanced much slower than in Europe. I go into details of why in the following story: Why Did Europe and Not China Dominate Gunpowder Warfare?

There are too many reasons to summarize here, but I will summarize the most important driving force: The European armored knight. European warfare was dominated by castle sieges and heavily armored knights and pikemen. To tackle this challenge, European developed ever more powerful crossbows with complex cranking mechanisms. It was the only way to pierce armor. Muskets caused a paradigm shift in this type of warfare. They were much faster to reload than the complex crossbows. The large metal bullets used by muskets had enough momentum to break through armor and kill knights.

For the curious: Bow, Crossbow and Musket Tactics Compared

Chinese warfare was entirely different. The primary opponents of the Chinese were horse riding light infantry such as the Mongols. Unlike European armies, these were not heavily armored. Hence, China did not engage in an arms race between projectile weapons and amor.

Making a steam engine is not merely about creating a cylinder with a piston. It also relies on developing an understanding of gas laws and vacuum. The study of vacuum involves the creation of high quality transparent glass. The precursor to the steam engine was the Newcomen atmospheric engine. It was based on rapidly cooling steam to create a vacuum inside a cylinder, which would then cause the piston to be sucked down. Without a proper understanding of how gases expand and contract as well as the nature of vacuum, it is hard to see how such an engine could have been developed.

Europe had a long list of scientists who explored the nature of vacuum, gases and volume long before any atmospheric engine was made:

• Evangelista Torricelli – Italian physicist and mathematician, and a student of Galileo, who invented the barometer in 1643.

• Blaise Pascal – Renowned French physicist, mathematician, and philosopher who did extensive experiments with vacuum, published in New experiments with the vacuum (“Experiences nouvelles touchant le vide”)

• Otto von Guericke – German scientist, inventor, and politician who invented the vacuum pump in 1654.

• Robert Boyle – Anglo-Irish natural philosopher, chemist, physicist, and inventor who described mathematically the relationship between pressure and volume.

• Robert Hooke – English polymath active as a scientist and architect who built the vacuum pumps used in Boyle’s experiments on gas law, and conducted many experiments himself.

There are more names than I can mention here. The key point is that a massive amount of study and experiments preceded the invention of the atmospheric engine and the steam engine. In other words, a key prerequisite for the Steam Engine was the European scientific revolution. We might thus ask why a scientific revolution happened in Europe and not in China. Naturally, many factors played a role, but perhaps one of the most crucial factors was the printing press.

You might ask why it matters that China did not have a printing press. It matters because there is a strong reason to believe that the scientific revolution was primarily caused by the introduction of the printing press. You may object that the Chinese already had, in fact, developed movable types before Europeans. However, the printing press was a revolutionary improvement over the movable types used in the far East: Why Was Western Printing Superior to Asian Printing?

Around 1600 European printing presses could output 1500 to 3600 pages per day. Chinese printing technique in contrast could only do about 40 pages per day.

As I discuss further in my article about the printing press it made accessing knowledge dramatically cheaper:

The printing press led to a sharp drop in book prices. From the invention of the printing press to 1500, books got about 60 times cheaper. By 1600 books had gotten 300 to a 1000 times cheaper.

I mentioned the scientific revolution and many of the people involved in developing modern chemistry, physics, and understanding of gases, volumes, and vacuum. However, I didn’t mention a material crucial in all the work they did: Glass. Modern physics could not have evolved without glass. Glass gave us spectacles, lenses, prisms, telescopes, microscopes, beakers, and bottles used in chemistry. Without a transparent glass container, it becomes very hard to study chemical reactions.

In the story, Did the Teacup Hinder Chinese Scientific Progress? I explore how the Chinese mastery of porcelain and paper making hindered development of sophisticated glassmaking techniques. Glass was simply rarely used in Chinese culture, while European culture had glass everywhere: Stained glass in churches and palaces, chandeliers, lanterns, and vine glasses and bottles.

Even if China had had the mathematics and the science, there was still many other mechanical challenges to overcome. James Watt’s Steam Engine consists of many mechanical parts. Europe had the conditions which allowed these mechanical parts to develop. Long before James Watt, Europe had evolved into a machine oriented society, while China had not. The question is why?

In my story The Missing Chinese Machine Revolution I explain in detail why a machine culture did not evolve in China. One observations stands out:

While artists such as Francesco di Giorgio (1439 – 1501) and Leonardo da Vinci (1452 – 1519) delighted in drawing mills, gears, and machines, their Chinese contemporaries drew flowers, fishes, and butterflies.

This machine culture had in part evolved from the excessive use of mills in Europe. The prevalence of mills in European society further contributed to the development of mechanical clocks and a thriving clock industry. In the story The Missing Chinese Mechanical Clocks I explain in more detail this connection between mills and clocks.

Why do mechanical clocks matter to the question of steam engines?

Clockmaking is important for many reasons, but in the context of this article, I would like to point out tha