The Loss and Rediscovery of the Steam Engine
However, in Hero’s day, the aeolipile was never widely used. For ancient Alexandria was not a mechanised society, and so the machine could only have a limited, novelty appeal. At best it would have been viewed as a teaching device, illustrating Hero’s principles- nothing more. So, the description of the aeolipile loitered dormant and disregarded in Hero’s papers, while time moved on and the use of steam faded. In the tenth century, there was a brief revival of interest, when a priest called Gerbert installed a steam-based hydraulic organ in a church in Rheims. However, it was not until the Renaissance that inventors and scientists once again noticed steam power.
These early Renaissance steam machines were much simpler than Hero’s aeolipile- although they had the same novelty value. In 1551, an Arabic inventor, Taqi al-Din created a rudimentary steam turbine which used a jet of steam to rotate a spit. By the seventeenth century, the Europeans had joined the trend. In 1615, Sol de Caus, a German engineer who worked for the elector palatine of Heidelberg, described his steam machine, a simple device that forced water in a copper wall through a tube through the application of steam.
In 1629, an Italian inventor Giovanni Branca constructed a ‘windmill’, whose wheel was turned by steam generated in a boiler. The games with steam then continued in England when in 1647, Nat Nye, a mathematician had the idea of powering guns with steam rather than gunpowder. The idea was a non-starter. In fact, it was another 30 years before a serious contender for a steam-powered machine to match that of Hero’s was on the horizon when in 1679, Denis Papin’s botched pressure-cooker experiment allowed him to conceive the notion of a steam engine. None of these attempts, however, were directly informed by Hero’s aeolipile.
However, it seems that there may have been a serious attempt to utilise Hero’s aeolipile and create a steam-powered machine a century before Papin. Documents preserved in the Royal Spanish Archives in Simancas suggest that in 1543, a Spanish naval captain called Blasco de Garay displayed a steam-powered ship in Barcelona harbour before Charles V, the Holy Roman emperor. The ship incorporated a copper boiler that produced the steam to turn two large wheels on either side of the vessel- thus propelling it through the water without the need for sails.
There are problems in authenticating this attempt. Apart from the fact that the steam-powered ship did not take off, the documents referring to the incident only date back to 1826. Furthermore, the sixteenth century was not a time Spain was noted to be involved with explorations of steam. However, even though the first Italian translation of Hero’s Pneumatics was still four years away, it is not inconceivable that de Garay had not acquired a working knowledge of Hero’s methods from elsewhere. By marrying these methods with elements of Roman and medieval naval technology, it may have been possible to produce a prototype steamship- and the first ever practical application of Hero’s aeolipile.
Where do we get this stuff? Here are our sources.
Denis Papin, Encyclopedia Brittanica, August 18, 2018
Heron of Alexandria, School of Mathematics and Statistics, University of St Andrews, Scotland, 1999
Who’s who in the Greek World, John Hazel, Routledge, 2002
Steam engine, Hmolpedia: An Encyclopedia of Human Thermodynamics