If there’s a single iconic invention in the history of engineering and technology it has to be the steam engine. Its story is often told and every British schoolchild knows it was invented by Thomas Newcomen. Well, not quite.
Newcomen was an inventor in the days when, unless you were an aristocrat with a lot of spare time, being a scientist wasn't considered a very good job. Coming from humble Devonport stock he was of a class known as schemers and was generally referred to as a blacksmith. Newcomen went to the mines of Cornwall to study the problem of pumping water out of deep diggings but, despite being the ‘father of the steam engine’, one of the first things he came across there was... a steam engine.
This steam engine had been built by Thomas Savery, who wrote about it in his book ‘An engine to raise water by fire’. Savery, who was much posher than Newcomen, had the grand title of military engineer although that didn't stop those in charge from snubbing him. When he suggested to the Admiralty a novel little idea he’d had for propelling a ship using paddle wheels, they couldn't see why they should "...have interloping people, that have no concern with us, to pretend to contrive or invent things for us"?
Savery built his ship anyway and paddled it up and down the Thames, but no-one important was watching so he turned his skills to inventing an engine for pumping out mines.
Well, at least that depends to some degree on your definition of ‘inventing’. There are rumours that Savery based his work on that of Edward Somerset, Second Marquis of Worcester, who a century earlier had pondered the knotty problem of perpetual motion. Another possible inventor of the steam engine, Jean Theophile Desaguliers claimed that Savery not only read Worcester’s book, but bought all the copies and burnt them so that he could claim to have invented the engine himself. Then there was the fact that Savery certainly based his boiler on Frenchman Denis Papin’s ‘digester’ or ‘pressure cooker’ of 1679.
Even if Savery did borrow and improve other people’s ideas he can still be credited with first realizing in practice what Worcester called his "semi-omnipotent and water commanding engine". Having perfected his model, he proudly displayed it at Hampton Court to King William III, who granted him a patent in 1689. But things did not work out well for Savery. Firstly, he decided to call his invention a ‘fire engine’ which was rather confusing, although he later changed this to ‘the miner’s friend’. His real problem however was that his engines were weak and used a huge amount of fuel to lift a small quantity of water. In short, donkeys and buckets were better. Mine owners were also rather frightened that his great hissing boilers might explode – which of course they did. Even after they had been fitted with pressure valves (invented by Desaguliers), they could still go wrong, as operators had the habit of putting weights on the valve to create more steam pressure and hence get their job done quicker. This was usually the last bright idea they ever had.
Newcomen realised that Savery had gone about the whole thing back-to-front. Savery used steam pressure to push a plunger up a piston. This meant you needed high steam pressure in a boiler which led to explosions. So Newcomen invented the ‘atmospheric engine’, which gained its power from the huge pressure of the atmosphere all around us. Newcomen filled a piston with steam and then suddenly cooled it, using water. This made the steam condense out, creating a partial vacuum in the piston tube which led to atmospheric pressure outside pushing the piston back down. Atmospheric pressure is enormous compared to the pressure in a dodgy ‘Papin pressure cooker’, so his engine was much more powerful.
And was the world impressed? No. Desaguliers grudgingly admitted that Newcomen and his partner John Calley had found a good solution but added: "Not being either philosophers to understand the reason, or mathematicians enough to calculate the powers and proportions of the parts, they very luckily, by accident, found what they sought for."
The very celebrated Robert Hooke was even more dismissive and told them they should never proceed with the idea in the first place. Perhaps Hooke was trying to buy time for his friend, the Dutch astronomer Christian Huygens, who had designed an engine driven by gunpowder.
By now you’re probably wondering who then actually did invent the steam engine, and the answer is simple – none of the above, for the steam engine had been invented over 1,600 years before. The only problem was no-one wanted it. The first steam powered device wasn't a simple steam engine, it was a fully formed jet turbine, invented sometime in the first century AD by Hero of Alexandria. It consisted of a boiler leading to a freely rotating copper sphere with two angled outlets. As the pressure built up in the sphere, steam shot out of the angled nozzles, making the whole thing spin round like a Catherine Wheel. At the time it was the fastest moving man-made object in the world. So impressed were the Romans, who then ruled Egypt, that they totally ignored the device. Had they taken it seriously, the industrial revolution might have started 2,000, rather than 300 years ago.
Hero’s problem was not a matter of what he did but of when he did it. Romans had slaves and the last thing they wanted was a machine that gave them time to, say, revolt. Hero had simply invented it too early leaving Newcomen to take the laurels a millennia-and-a-half later – which just goes to show that in engineering, timing is everything.
