Throughout history there are great people that bring humanity into a new age, decades or even centuries ahead of their time. Archimedes, Da Vinci, Tesla and Einstien: All geniuses who took what was already known and put it together in a completely new way, changing the face of the world forever. For the famous inventors we might see sketches of everyday products in manuscripts from the last century. An example: Nicola Tesla designed and built a boat that could be controlled from a handheld device that sent out radio signals--in the 1890s. Historians have uncovered sketches of modern bicycles and basic helicopters--from the 1490s. But there was one man whose vision for the future made Da Vinci seem slow, whose talent for execution would make Tesla's fans cry with frustration.
His name was Heron, or Hero, and he lived in Alexandria. And while Tesla invented remote control a full century before RC cars hit the shelves, while Da Vinci drew the bicycle as it would appear four hundred years later, Heron built a steam engine nearly 1700 years before an experimental model began pumping out a mine in England.
Heron was an inventor born less than 60 years after Julius Caesar uttered the famous words, "Et tu, Brute?" He lived in Alexandria, a metropolis where the riches of the fertile Nile River Valley were shipped to the great cities of Greece and Italy, where Roman, Ionian, Arabic, Egyptian, and African merchants came to do business--and immigrants came to make a new living. While Rome was the Washington, D.C. of the Roman Empire, Alexandria was the New York City of the Western World. Heron lived in this city as an inventor, a creator of incredible machines that would have sold well in Elizabethan England, a millennium and a half later.
He made mechanical plays that told ancient myths while the operator turned the driving wheel. These plays were not simple Victorian automota. Each piece was removable, and had two different settings depending on what action needed to be performed. He designed a hand-powered water pump that was widely adopted in Rome for its use in putting out fires. A slightly improved design was used by Benjamin Franklin in the 1770s when he founded the first public fire company. However, these are small things compared to his most famous achievement: the aeolipile.
The aeolipile was a simple toy that used steam to spin a ball around an axle at high speeds. Water was heated by a fire and sent through tubes to a freely spinning ball with two tubes pointing in opposite directions set diametrically opposite to each other. A simple Google search will provide a better description than I can. While it was seen by many as just a toy, some saw it as a bit more. A modified aeolipile was used in one of the many temples in Alexandria to open its heavy front doors every morning. Had it taken more root, the aeolipile could have led an young Roman Empire into the Industrial Era within the lifetime of the Twelve Apostles.
The economic need was there, although it would have required a keen business eye to identify it. While slave power was plentiful, jobs of high power required a large number of workers. Workers that needed to be fed, clothed, and given shelter. Roman slaves were not the same as their American counterparts 1200 years later. Rather than being thought of as livestock, slaves were considered high-end appliances. Rather than receiving all of the respect of an ox or pig, Roman slaves were thought of the same way we think of our TVs, our smartphones, our stoves. They were kept in good condition so that they could work hard. And that made them expensive. A good example of this was the diolkos, a form of railway used by ships to portage large ships across some isthmuses. Unfortunately, these died out in the first century C.E. Had they stuck around longer, an advanced aeolipile might have been commissioned for the heaviest labor of the job: getting the boat out of the water. After its economic and public debut, the aeolipile might become popular for the heavy jobs that required a lot of work, such as heavy construction and, eventually, high-speed transport.
However, the aeolipile is not the catalyst of an Industrial Revolution. It is too weak, and too inefficient. Heron knew about pistons and gas pressure; his water pump used the selfsame idea. A simple leap not rare for him could have led to the invention of a steam piston engine near the end of Heron's life, a little over a decade before the eruption of Mt. Vesuvius. The Romans also had access to carbon steel, and enough of it to make it general issue for their extensive army.
Here I posit my alternative timeline:
40 CE: An inventor in Alexandria, by the name of Heron, describes an idea for turning steam into rotational energy via a simple machine. He sells the idea to a local temple, which uses it for a simple wonder. Soon afterward Heron convinces the priests to use it to open their heavy front door every morning.
45 CE: A businessman visits a temple in Alexandria, praying for a solution to his business problems; his overland canal system is beginning to draw up more expenses than it pays for. Glancing up, he sees the priests using a machine to open their very heavy door. Struck with inspiration, he asks the priests where they found such a machine. They direct him to Heron's home, where he contracts Heron to build a larger version to replace a portion of his slave force. Heron accepts.
45 CE (later): While working on the improved design, Heron has a flash of insight. A new way to combine his water pump with steam power! However, he is much too busy with his contract to work on it. He writes down the machine on papyrus for a later date.
46 CE: The aeolipile works, and the investment makes Heron a rich man. He uses his spare time continuing his research, now at a faster pace due to his better source of funds. By his death in 90 CE he has changed the world forever. From his mechanical shows grew large plants for mass-producing textiles and grinding grain as the raw materials float down the Nile, all powered by his piston engine.
96 CE: The first of the Five Good Emperors, Nerva, comes to power, and the Golden Age of the Roman Empire begins. He invests in Heron's works and brings his greatest wise men to try to study and improve on his work. Progress is slow.
115 CE: After the first successful test of the Iron Chariot on the small scale, Emperor Trajan orders that all military roads in Gaul, Hispania, and Britannia be upgraded to allow Iron Chariots to travel along them, especially near the German border. The increased demand for iron and coal makes the Isle of Britannia a rich province.
140 CE: The Roman Empire begins to feel the first impacts of industrialization, but not nearly as much as her neighbors. An increased population provides more men for the army, increased productivity provides them with more than enough arms, and the Roman knack for infrastructure combined with railways allows for troop transport faster than ever seen before by a factor of 10. Rome takes all of the British Isles rather than stopping at Hadrian's wall. Exploratory expeditions are sent to Iceland and Greenland, but without steam-powered ships the Romans find no hint of the New World. The German tribes are taken over, and the Emperor has spheres of influence far beyond the Arabic peninsula. The Silk Road benefits hugely from the railroad, as travel times across the deserts of Arabia and Mongolia are slashed. Of course, such benefits are not free. The Empire owns the rails, the engines, and the cars, and merchants are expected to pay a tax in order to use such a valuable service. This makes Rome greater, and richer, than ever before.
150 CE: Greek inventors develop the paddleboat. The Romans never had a navy and so never explored the possibility of steam-powered ships. However, though decades of industrial espionage, ingenious deduction, and good old-fashioned trial and error, the Greeks develop the steam-powered trireme. While this does improve trade in the Mediterranean, it has a much larger impact: when the Emperor finds out that the Greeks had stolen Imperial property, he is furious. As a punishment he orders them banished, telling them that if they find more land to the north they will be able to return home. With this new, faster transport, they sail past Iceland and Greenland until they finally reach Canada. The report very positive; a completely new land with rich soil and no civilized nations to get in the way. A follow-up team led by a Roman general predicts and easier colonization than Gaul or Britain.
That's pretty much as far as I can get, though I'm not good at predicting political butterflies. What do you think?
Oh, and for the TL;DR: The Romans almost got steam power; Heron had 90% of the technology, and the Roman Empire would have amplified the speed of the Revolution. My timeline starts at the RED word.