The ancient invention of the steam engine by the Hero of Alexandria
In our society today we are often surprised and impressed by the advancement of technology and engineering, a major characteristic of our civilisation. However if we look back more than 2,000 years ago, we can find mechanical marvels and incredible feats of engineering that were ahead of their time. Many became lost to the pages of history, only to become reinvented just a few centuries ago. This includes the first modern of the steam engine.
Heron Alexandrinus, or Hero of Alexandria as he was often known, was a Greek born in 10AD in Alexandria, now part of Egypt, and the second largest city after Cairo. Little is known about the life of Heron, however, we are aware that he was born to Greek parents that migrated to Alexandria after the conquest of Alexander the Great. Heron was a mathematician and an engineer considered to be one of the greatest inventors of ancient times.
During the era in which Heron lived, the great Library of Alexandria was in its glory and Heron is believed to have taught at the Museum of Alexandria, a place for scientists and scholars to meet and discuss.
What very few people know, thanks to the omission of important facts from our history books, is that Heron was the first inventor of the steam engine, a steam powered device that was called aeolipile or the ‘Heron engine’. The name comes from the greek word ‘Aiolos’ who was the Greek God of the winds.
Although a few others have talked about devices similar to aeolipiles before Heron, Heron was the first one to describe them in detail and give instructions for manufacturing them in his book Pneumatica, where more than 78 devices are described. Many of Heron’s ideas were extensions and improvements of another Greek inventor who lived in Alexandria 300 years before him, known as Ktesibios, the first to write about the science of compressed air.
But what is an aeolipile? It is a sphere that is positioned in such a way that it can rotate around its axis. Nozzles that are opposite to each other would expel steam and both of the nozzles would generate a combined thrust resulting in torque, causing the sphere to spin around its axis. The rotation force speeds up the sphere up to the point where the resistance from traction and air brings it to a stable rotation speed. The second video at the end of this article demonstrates how it works.
The steam was created by boiling water either inside the sphere or under it, as seen in the image. If the boiler is under the sphere, then it is connected to the rotating sphere through a pair of pipes that at the same time serve as pivots for the sphere. The replica of Heron’s machine could rotate at 1,500 rounds per minute with a very low pressure of 1.8 pounds per square inch.
PLACE a cauldron over a fire: a ball shall revolve on a pivot. A fire is lighted under a cauldron, A B, (fig. 50), containing water, and covered at the mouth by the lid C D; with this the bent tube E F G communicates, the extremity of the tube being fitted into a hollow ball, H K. Opposite to the extremity G place a pivot, L M, resting on the lid C D; and let the ball contain two bent pipes, communicating with it at the opposite extremities of a diameter, and bent in opposite directions, the bends being at right angles and across the lines F G, L M. As the cauldron gets hot it will be found that the steam, entering the ball through E F G, passes out through the bent tubes towards the lid, and causes the ball to revolve, as in the case of the dancing figures.
This invention was forgotten and never used properly until 1577, when the steam engine was re-invented by the philosopher, astronomer and engineer, Taqu al-Din. But he basically described the same device as Heron, a method for rotating a spit by using jets streams on the periphery of a wheel.
Reconstruction of one of many “automata” of Heron (Source)
Another invention of Heron was the ‘wind wheel’, a wind-driven wheel that was used to power a machine that was connected to a pipe organ. He also invented the first vending machine, automatic opening doors, ‘miraculous’ movements and sounds in temples, a fire engine, a standalone fountain, and many of the mechanisms of the Greek theatre. One of his theatrical mechanical inventions included a completely mechanical robotic theatrical play by using a binary system of knots and ropes and simple machines, even creating artificial sounds of thunder, pumps and concentration of light to specific parts of the performance. His works include descriptions of machines working on air, steam or water pressure, architectural devices for lifting heavy objects, methods of calculating surfaces and volumes – including a method of calculating the square root, war machines, and manipulation of light using reflection and mirrors.
It is clear that Heron was a genius with knowledge that was incredibly advanced for the time. Unfortunately, most of his original writings have been lost, with just a few surviving in Arabic Manuscripts. Who knows how many more incredible inventions were documented by Heron more than 2,000 years ago.
By John Black
Pneumatica – Hero of Alexandria
Uvumbuzi wa injini ya mvuke na Hero wa Alexandria Katika jamii yetu ya leo, mara nyingi tunashangazwa na kuvutiwa na maendeleo ya teknolojia na uhandisi, sifa kuu ya ustaarabu wetu. Hata hivyo, ikiwa tutaangalia nyuma zaidi ya miaka 2,000 iliyopita, tunaweza kupata maajabu ya mitambo na kazi za uhandisi zisizo za kawaida ambazo zilikuwa mbele ya wakati wao. Wengi wao walipotea katika kurasa za historia, lakini walianzishwa upya karne chache tu zilizopita. Hilo latia ndani injini ya mvuke ya kwanza ya kisasa. Heron Alexandrinus, au Hero wa Alexandria, alikuwa Mgiriki aliyezaliwa mnamo 10 KK huko Alexandria, sasa sehemu ya Misri, na mji wa pili kwa ukubwa baada ya Cairo. Ingawa hakuna habari nyingi kuhusu maisha ya Heroni, inaonekana kwamba alizaliwa na wazazi Wagiriki waliohamia Aleksandria baada ya ushindi wa Aleksanda Mkuu. Heron alikuwa mwanahisabati na mhandisi aliyehesabiwa kuwa mmoja wa wavumbuzi wakubwa zaidi wa nyakati za kale. Wakati Heron aliishi, Maktaba kubwa ya Alexandria ilikuwa katika utukufu wake na Heron anaaminika kuwa alifundisha katika Jumba la Makumbusho la Alexandria, mahali ambapo wanasayansi na wasomi walikutana na kujadili. "Watu wachache sana wanajua, kwa sababu ya kuachwa kwa ukweli muhimu kutoka kwa vitabu vyetu vya historia, ni kwamba Heron alikuwa mvumbuzi wa kwanza wa injini ya mvuke, kifaa cha mvuke kinachoitwa ""aolipile"" au ""injini ya Heron.""" Jina hilo linatokana na neno la Kigiriki <unk>Aiolos<unk> ambaye alikuwa mungu wa Kigiriki wa upepo. Ingawa wengine kadhaa wamezungumza juu ya vifaa kama vile Aeolipids kabla ya Heron, Heron alikuwa wa kwanza kuelezea kwa undani na kutoa maelekezo ya utengenezaji wao katika kitabu chake Pneumatica, ambapo vifaa zaidi ya 78 vimeelezwa. "Hero aliandika ""Ktesibios"" ambaye aliishi miaka 300 kabla yake huko Aleksandria, na alikuwa mtu wa kwanza kuandika juu ya sayansi ya hewa iliyofinyangwa." Lakini aeolipile ni nini? Ni mviringo uliowekwa kwa njia ambayo unaweza kuzunguka mhimili wake. Nozzles ambayo ni kinyume na kila mmoja itakuwa kuondoa mvuke na wote wawili nozzles itazalisha mchanganyiko thrust kusababisha torque, kusababisha dunia kuzunguka mhimili wake. Nguvu ya mzunguko huongeza kasi ya mviringo hadi mahali ambapo upinzani kutoka kwa traction na hewa huleta kwa kasi ya mzunguko thabiti. Video ya pili iliyo kwenye mwisho wa makala hii inaonyesha jinsi inavyofanya kazi. Mvuke huo ulitokezwa kwa kuchemka kwa maji ndani ya mviringo huo au chini yake, kama inavyoonekana katika picha. Kama boiler ni chini ya dunia, basi ni kushikamana na dunia mzunguko kwa njia ya jozi ya mabomba ambayo wakati huo huo kutumika kama pivots kwa dunia. "Mfano wa ""Heron"" unaweza kuzunguka kwa kasi ya mizunguko 1,500 kwa dakika na shinikizo la chini sana la pauni 1.8 kwa inchi mraba." Weka cauldron juu ya moto: mpira lazima kuzunguka juu ya pivot. Moto ni mwanga chini ya cauldron, A B, (fig. "Hili ni kwa sababu ya ""mwisho wa bomba"" (Hk) na ""mwisho wa bomba"" (Hk) na ""mwisho wa bomba"" (Hk) na ""mwisho wa bomba"" (Hk) na ""mwisho wa bomba"" (Hk) na ""mwisho wa bomba"" (Hk) na ""mwisho wa bomba"" (Hk) na ""mwisho wa bomba"" (Hk) na ""mwisho wa bomba"" (Hk) na ""mwisho wa bomba"" (Hk)." Katika miaka ya 1577 na 1587 injini ya mvuke ilibuniwa na mwanafalsafa, mtaalamu wa nyota na mhandisi Taqwa al-Din. "Hiyo ni kwa sababu ya ""Heron"" - njia ya kuzungusha spit kwa kutumia jets ya mtiririko kwenye pembe ya gurudumu." "Mfano wa ""automata"" ni ""mwisho wa mzunguko wa upepo"" (wind wheel) ambao ni mashine ya kuendesha gari iliyounganishwa na mzunguko wa mzunguko wa upepo." Pia alivumbua mashine ya kwanza ya kuuza bidhaa, milango ya kufunguliwa moja kwa moja, miendo na sauti za "miujiza" katika mahekalu, gari la kuzima moto, chemchemi ya kujitegemea, na mifumo mingi ya ukumbi wa michezo wa Kigiriki. Moja ya uvumbuzi wake wa mitambo ni pamoja na mchezo wa michezo ya roboti ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo ya mitambo. Kazi zake ni pamoja na maelezo ya mashine kufanya kazi juu ya hewa, mvuke au maji shinikizo, vifaa vya usanifu kwa ajili ya kuinua vitu nzito, mbinu za kuhesabu nyuso na kiasi - ikiwa ni pamoja na mbinu ya kuhesabu mzizi mraba, mashine za vita, na udhibiti wa mwanga kwa kutumia kutafakari na vioo. Ni wazi kwamba Heroni alikuwa mtu mwenye akili nyingi na alikuwa na ujuzi uliokuwa wa hali ya juu sana kwa wakati huo. Kwa kusikitisha, maandishi yake mengi ya awali yamepotea, na ni machache tu yaliyohifadhiwa katika Hati-mkono za Kiarabu. Ni nani anayejua ni uvumbuzi gani wa ajabu ulioandikwa na Heron zaidi ya miaka 2,000 iliyopita? Na John Black Pneumatica <unk> Hero wa Alexandria