Hero of Alexandria

Who invented the steam engine and when did he do it? Most people would say James Watt invented the steam engine around 1776. That is not quite true, however. Although Watt was a brilliant scientist and inventor, he really only improved an earlier design by Thomas Newcomen, who had developed a device to pump water out of mines in 1712. Should Thomas Newcomen get the credit for inventing the steam engine? He wasn’t the first person to experiment with machines powered by steam. Who was the first and when? How about Hero of Alexandria way back in the first century AD? That’s right. The first machine to use steam power was invented at around or just after the time of Christ.

Hero of Alexandria was a Greek mathematician and scientist who lived in the city of Alexandria, Egypt from around AD 10-70. He worked at the famous Library of Alexandria. This library was not just a collection of books. The library was part of a larger institution called the Musaeum (our word museum is derived from this. The Musaeum was not a museum in the modern sense, a collection of art or artifacts arranged for public viewing. Rather, it was a sort of home and workplace for scholars which was set up and subsidized by the Ptolemaic kings of Egypt. The Musaeum was the closest thing the ancient world had to a university. Here, Euclid developed the principles of geometry and Eratosthenes accurately measured the circumference of the each. Archimedes taught there, Aristarchus proposed the first heliocentric theory of the solar system, Hero of Alexandria conducted experiments in what would now be called mechanics and thermodynamics.

Hero has been credited with several inventions,including a windmill, a vending machine to distribute holy water, a syringe, and special effects for the theater. He developed a method for calculating square roots, Heron’s formula for calculating the area of a triangle from the length of its sides and was the first mathematician to explore the concept of imaginary numbers. He also invented a steam engine, or aeolipile. This device consisted of a boiler or tub of water which was heated. The steam from the water was conducted through tubes to a sphere or cylinder which has nozzles sticking out of it. As the steam escaped through the nozzles, it caused the sphere to whirl around. Here is a diagram which might better explain things.


Here is a picture of a modern reconstruction of the aeolipile.


The aeolipile wasn’t really much more than a toy and couldn’t be used for any practical purpose. Still, I have to wonder, why wasn’t the device further developed until someone invented a working steam engine 1600 years before Watt and Newcomen? Why wasn’t there an scientific and industrial revolution in the time of the Roman Empire? Was it because the large number of slaves discouraged the invention of labor saving devices? Was the Greco-Roman intellectual elite averse to getting their hands dirty with experiments and practical inventing? Was work like Hero’s too uncomfortably close to being the sort of work the lower classes did? There is no way to know. For that matter, why did the scientific revolution only occur in Western Europe around 1500? Why did the industrial revolution begin in England in the late 1700s and no where else? Europeans are not noticeably more intelligent than people from other regions, so why?

Africa,the Americas, and Australia are easy to explain. The largest landmass on Earth is Eurasia, or the continents of Europe and Asia. This is where the great majority of the people on Earth have lived. Most of what we consider to be history has occurred in Eurasia, especially in a band roughly between 30 and 50 degrees of latitude. Northern Europe and Britain is a bit north of this and India extends to the south but it is close enough. According to Jared Diamond in Guns, Germs, and Steel, this band has a roughly similar climate, length of growing season, etc and travel and trade is relatively easy along this band.  The Americas and Australia are separated from this landmass by ocean and Africa by the Sahara Desert. Tropical Africa is not very conducive for the development of advanced civilization because of its climate and ecology. This still leaves about four centers of civilization, Europe, the Middle East, India, and China. Each of these centers had certain advantages and disadvantages, yet only Europe developed modern science and technology. This isn’t a case of Europe happening to be first. None of the other centers were even beginning the process. If some plague had wiped out the entire population of Europe, perhaps a more virulent form of the Black Death, it is likely that we would still be at a medieval level of technology. Why?

The Chinese were gifted inventors and observers of the natural world. The records of Chinese astrologers are more complete than anything in the West and modern astronomers find their records useful. The Chinese invented the printing press, paper, gunpowder, the compass, and many other things. Yet, somehow, they never managed to develop a continuous scientific tradition. Chinese history has examples of scientist discovering things, only to be forgotten and rediscovered centuries later. They invented the printing press, but this invention didn’t have the sort of disruptive effect it had in the West. Was Chinese culture too conservative? Did the existence of a centralized state for much of Chinese history discourage innovation?

The Indians were great mathematicians. They invented the zero and “Arabic numerals”. Their achievements in practical technology were somewhat less impressive. Why? Did Hindu pantheism and the concept of the material world being an illusion discourage investigation into the natural world? The Moslems were also good mathematicians and made some progress in the sciences of chemistry and optics. They had the advantage of controlling the trade routes of Eurasia and could benefit most from the achievements of other cultures. They also had the heritage of Greek philosophy in the lands they conquered. Yet ultimately their progress slowed and from being among the most advanced civilization in the world, they slipped to being among the most backward. Did Islamic contempt for secular philosophy play a role?

These questions are unanswerable. It is interesting to speculate on what might have happened and alternative history is one of most favorite sub-genres of science fiction. Perhaps it is just as well the industrial revolution didn’t occur in Roman times. The Romans were not a kindly people and it might be better than they didn’t have guns or nukes.