Alexandria (/ˈhɪəroʊ/; Greek: Ἥρων ὁ
Ἀλεξανδρεύς, Heron ho Alexandreus; also known as Heron of
Alexandria /ˈhɛrən/; c. 10 AD – c. 70 AD) was a mathematician and
engineer who was active in his native city of Alexandria, Roman Egypt.
He is considered the greatest experimenter of antiquity and his
work is representative of the Hellenistic scientific tradition.
Hero published a well recognized description of a steam-powered device
called an aeolipile (sometimes called a "Hero engine"). Among his most
famous inventions was a windwheel, constituting the earliest instance
of wind harnessing on land. He is said to have been a follower
of the atomists. Some of his ideas were derived from the works of
Much of Hero's original writings and designs have been lost, but some
of his works were preserved in Arabic manuscripts.
1 Life and career
4 Cultural references
6 See also
8 Further reading
9 External links
Life and career
Hero may have been either a Greek or a Hellenized
Egyptian. It is almost certain that Hero taught at the
Musaeum which included the famous Library of Alexandria, because most
of his writings appear as lecture notes for courses in mathematics,
mechanics, physics, and pneumatics. Although the field was not
formalized until the twentieth century, it is thought that the work of
Hero, his automated devices in particular, represents some of the
first formal research into cybernetics.
Hero described the construction of the aeolipile (a version of
which is known as Hero's engine) which was a rocket-like reaction
engine and the first-recorded steam engine (although Vitruvius
mentioned the aeolipile in
De Architectura some 100 years earlier than
Hero). It was created almost two millennia before the industrial
revolution. Another engine used air from a closed chamber heated by an
altar fire to displace water from a sealed vessel; the water was
collected and its weight, pulling on a rope, opened temple doors.
Some historians have conflated the two inventions to assert that the
aeolipile was capable of useful work.
Hero's wind-powered organ (reconstruction)
The first vending machine was also one of his constructions; when a
coin was introduced via a slot on the top of the machine, a set amount
of holy water was dispensed. This was included in his list of
inventions in his book
Mechanics and Optics. When the coin was
deposited, it fell upon a pan attached to a lever. The lever opened up
a valve which let some water flow out. The pan continued to tilt with
the weight of the coin until it fell off, at which point a
counter-weight would snap the lever back up and turn off the
A windwheel operating an organ, marking the first instance in history
of wind powering a machine.
Hero also invented many mechanisms for the Greek theater, including an
entirely mechanical play almost ten minutes in length, powered by a
binary-like system of ropes, knots, and simple machines operated by a
rotating cylindrical cogwheel. The sound of thunder was produced by
the mechanically-timed dropping of metal balls onto a hidden drum.
The force pump was widely used in the Roman world, and one application
was in a fire-engine.
A syringe-like device was described by Hero to control the delivery of
air or liquids.
In optics, Hero formulated the principle of the shortest path of
light: If a ray of light propagates from point A to point B within the
same medium, the path-length followed is the shortest possible. It was
nearly 1000 years later that
Alhacen expanded the principle to both
reflection and refraction, and the principle was later stated in this
Pierre de Fermat
Pierre de Fermat in 1662; the most modern form is that the
path is at an extremum.
A standalone fountain that operates under self-contained hydrostatic
energy (Hero's fountain)
A programmable cart that was powered by a falling weight. The
"program" consisted of strings wrapped around the drive axle.
Hero described a method for iteratively computing the square root of a
number. Today, however, his name is most closely associated with
Hero's formula for finding the area of a triangle from its side
lengths. He also devised a method for calculating cube roots in the
1st century CE.
A 1979 Soviet animated short film focuses on Hero's invention of the
aeolipile, showing him as a plain craftsman who invented the turbine
A 2007 The History Channel television show Ancient Discoveries
includes recreations of most of Hero's devices
A 2010 The History Channel television show
Ancient Aliens episode
"Alien Tech" includes discussion of Hero's steam engine
A 2014 The History Channel television show Ancient Impossible episode
Science Fiction novel "The Plot to Save Socrates"
asserts that Hero was an American time traveler.
The book About automata by Hero of
Alexandria (1589 edition)
The most comprehensive edition of Hero's works was published in five
volumes in Leipzig by the publishing house Teubner in 1903.
Works known to have been written by Hero:
Pneumatica (Πνευματικά), a description of machines working
on air, steam or water pressure, including the hydraulis or water
Automata, a description of machines which enable wonders in temples by
mechanical or pneumatical means (e.g. automatic opening or closing of
temple doors, statues that pour wine, etc.); See
Bernardino Baldi's translation
Mechanica, preserved only in Arabic, written for architects,
containing means to lift heavy objects
Metrica, a description of how to calculate surfaces and volumes of
On the Dioptra, a collection of methods to measure lengths, a work in
which the odometer and the dioptra, an apparatus which resembles the
theodolite, are described
Belopoeica, a description of war machines
Catoptrica, about the progression of light, reflection and the use of
Works that sometimes have been attributed to Hero, but are now thought
most likely to have been written by someone else:
Geometrica, a collection of equations based on the first chapter of
Stereometrica, examples of three-dimensional calculations based on the
second chapter of Metrica
Mensurae, tools which can be used to conduct measurements based on
Stereometrica and Metrica
Cheiroballistra, about catapults
Definitiones, containing definitions of terms for geometry
Works that are preserved only in fragments:
^ Genitive: Ἥρωνος.
^ a b Research Machines plc. (2004). The Hutchinson dictionary of
scientific biography. Abingdon, Oxon: Helicon Publishing. p. 546.
Alexandria (lived c. AD 60) Greek mathematician and engineer,
the greatest experimentalist of antiquity
^ Marie Boas, "Hero's Pneumatica: A Study of Its Transmission and
Influence", Isis, Vol. 40, No. 1 (Feb., 1949), p. 38 and supra
^ a b A.G. Drachmann, "Heron's Windmill", Centaurus, 7 (1961), pp.
^ a b Dietrich Lohrmann, "Von der östlichen zur westlichen
Windmühle", Archiv für Kulturgeschichte, Vol. 77, Issue 1 (1995),
pp. 1–30 (10f.)
George Sarton (1936). "The Unity and Diversity of the Mediterranean
World", Osiris 2, p. 406-463 
^ John H. Lienhard (1995). "Hero of Alexandria". The Engines of Our
Ingenuity. Episode 1038. NPR. KUHF-FM Houston.
^ T. D. De Marco (1974). "Gas-
Turbine Standby-Power Generation for
Water-Treatment Plants", Journal American
Water Works Association 66
(2), p. 133-138.
^ Justin E. Wilson (2006). Heron’s Formula Archived 2009-03-26 at
the Wayback Machine., University of North Carolina at Charlotte.
^ Victor J. Katz (1998). A History of Mathematics: An Introduction, p.
184. Addison Wesley, ISBN 0-321-01618-1: "But what we really want
to know is to what extent the Alexandrian mathematicians of the period
from the first to the fifth centuries C.E. were Greek. Certainly, all
of them wrote in Greek and were part of the Greek intellectual
community of Alexandria. And most modern studies conclude that the
Greek community coexisted [...] So should we assume that
Diophantus, Pappus and
Hypatia were ethnically Greek, that their
ancestors had come from Greece at some point in the past but had
remained effectively isolated from the Egyptians? It is, of course,
impossible to answer this question definitively. But research in
papyri dating from the early centuries of the common era demonstrates
that a significant amount of intermarriage took place between the
Greek and Egyptian communities [...] And it is known that Greek
marriage contracts increasingly came to resemble Egyptian ones. In
addition, even from the founding of Alexandria, small numbers of
Egyptians were admitted to the privileged classes in the city to
fulfill numerous civic roles. Of course, it was essential in such
cases for the
Egyptians to become "Hellenized," to adopt Greek habits
and the Greek language. Given that the Alexandrian mathematicians
mentioned here were active several hundred years after the founding of
the city, it would seem at least equally possible that they were
ethnically Egyptian as that they remained ethnically Greek. In any
case, it is unreasonable to portray them with purely European features
when no physical descriptions exist."
^ Kelly, Kevin (1994). Out of control: the new biology of machines,
social systems and the economic world. Boston: Addison-Wesley.
^ Hero (1899). "Pneumatika, Book ΙΙ, Chapter XI". Herons von
Alexandria Druckwerke und Automatentheater (in Greek and German).
Wilhelm Schmidt (translator). Leipzig: B.G. Teubner.
^ Hero of
Alexandria (1851). "Temple Doors opened by Fire on an
Pneumatics of Hero of Alexandria. Bennet Woodcroft (trans.).
London: Taylor Walton and Maberly (online edition from University of
Rochester, Rochester, NY). Archived from the original on 2008-05-09.
^ For example: Mokyr, Joel (2001). Twenty-five centuries of
technological change. London: Routledge. p. 11.
ISBN 0-415-26931-8. Among the devices credited to Hero are the
aeolipile, a working steam engine used to open temple doors and
Wood, Chris M.; McDonald, D. Gordon (1997). "History of propulsion
devices and turbo machines". Global Warming. Cambridge, England:
Cambridge University Press. p. 3. ISBN 0-521-49532-6. Two
exhaust nozzles...were used to direct the steam with high velocity and
rotate the sphere...By attaching ropes to the axial shaft Hero used
the developed power to perform tasks such as opening temple
^ Humphrey, John W.; John P. Oleson; Andrew N. Sherwood (1998). Greek
and Roman technology: A Sourcebook. Annotated translations of Greek
and Latin texts and documents. Routledge Sourcebooks for the Ancient
World. London and New York: Routledge.
ISBN 978-0-415-06137-7. , pp. 66–67
^ Woodcroft, Bennet (1851). The
Pneumatics of Hero of Alexandria.
London: Taylor Walton and Maberly. Retrieved January 27, 2010. No. 57.
Description of a Syringe [permanent dead link]
Noel Sharkey (July 4, 2007), A programmable robot from AD 60, 2611,
The above citation embeds a video using Flash Player, which fewer
devices support over time. The same video is also available at this
^ Heath, Thomas (1921). A History of Greek Mathematics, Vol. 2.
Oxford: Clarendon Press. pp. 323–324.
^ Smyly, J. Gilbart (1920). "Heron's Formula for Cube Root".
Hermathena. Trinity College Dublin. 19 (42): 64–67.
^ Jamies W. McKinnon. "Hero of
Alexandria and Hydraulis". In L. Root,
Deane. Grove Music Online. Oxford Music Online. Oxford University
Press. (subscription required)
^ De gli automati, overo machine se moventi,
Volume 2 (Venice, 1589;
repr. 1601), On Automaton; translated from the Greek.
^ O'Connor, J.J. & E.F. Robertson. "Heron biography". The MacTutor
Mathematics archive. Retrieved 2006-06-18.
Drachmann, Aage Gerhardt (1963). The Mechanical Technology of Greek
and Roman Antiquity: A Study of the Literary Sources. Madison, WI:
University of Wisconsin Press.
Landels, J.G. (2000). Engineering in the ancient world (2nd ed.).
Berkeley: University of California Press.
Marsden, E.W. (1969). Greek and Roman Artillery: Technical Treatises.
Oxford: Clarendon Press.
Schellenberg, H.M.: Anmerkungen zu Hero von
Alexandria und seinem Werk
über den Geschützbau, in: Schellenberg, H.M./ Hirschmann, V.E./
Krieckhaus, A.(edd.): A Roman Miscellany. Essays in Honour of Anthony
R. Birley on his Seventieth Birthday, Gdansk 2008, 92-130 (with a huge
bibliography of over 300 titles and discussion of the communis opinio
Wikimedia Commons has media related to Hero of Alexandria.
Wikisource has original text related to this article:
Ἥρων ὁ Ἀλεξανδρεύς
Wikisource has the text of the 1911
Encyclopædia Britannica article
Hero of Alexandria.
Webpage about Hero by The Technology Museum of Thessaloniki
A translation of Pneumatica with diagrams
Heron biography, The MacTutor History of
Alexandria in the 1911 Encyclopædia Britannica
Alexandria in online Encyclopædia Britannica
Online Galleries, History of Science Collections, University of
Oklahoma Libraries High resolution images preserved at The Internet
"Hero of Alexandria". New International Encyclopedia.
Reconstruction of Heron’s Formulas for Calculating the
Spiritali di Herone Alessandrino From the John Davis Batchelder
Collection at the Library of Congress
Pneumatics of Hero of Alexandria, from the Original Greek. Tr. and
ed. by Bennet Woodcroft From the Collections at the Library of
Ancient Greek mathematics
Aristaeus the Elder
Isidore of Miletus
Theon of Alexandria
Theon of Smyrna
Zeno of Elea
Zeno of Sidon
On the Sizes and Distances (Aristarchus)
On Sizes and Distances
On Sizes and Distances (Hipparchus)
On the Moving Sphere (Autolycus)
The Sand Reckoner
Problem of Apollonius
Squaring the circle
Doubling the cube
Library of Alexandria
Timeline of Ancient Greek mathematicians
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