Hero (or Heron) of Alexandria (c. 10 – 70) was a Greek engineer and geometer in Alexandria, Hellenistic Egypt. His most famous invention was the first documented steam engine, the aeolipile. He is said to have been a follower of the Atomists. Some of his ideas were derived from the works of Ctesibius.

A number of references mention dates around 150 BC, but these are inconsistent with the dates of his publications and inventions. This may be due to a misinterpretation of the phrase "first century" or a confusion of this Hero with other Heros - Hero was not an uncommon name.

It is also believed that Hero taught at the Museum in Alexandria because most of his writings appear as lecture notes for courses in mathematics, mechanics, physics and pneumatics.

Projects

• steam turbine (50/62/70) (aeolipile) - the first recorded steam engine, (known as Hero's Engine) which was created almost two millennia before the industrial revolution, which was powered by steam engines. Apparently Hero's steam engine was taken to be no more than a toy, and thus its full potential not realized for quite some time.

Bibliography

• Pneumatica, a description of machines working on air, steam or water pressure.
• 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.).
• Mechanica, written for architects, containing means to lift heavy objects.
• Metrica, a description of how to calculate surfaces and volumes of diverse objects.
• On the Dioptra, a collection of methods to measure lengths. In this work the odometer is described, and also an apparatus which resembles a theodolite.
• Belopoeica, a description of war machines.
• Catoptrica, about the progression of light, reflection and the use of mirrors.

Works which have sometimes been attributed to Hero, but are now thought to have most likely been written by someone else:

• Geometria, a collection of equations based on the first chapter of Metrica.
• 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.
• Cheirobalistra, about catapults.
• Definitiones, containing definitions of terms for geometry.

References