Hero (or Heron) of Alexandria was among the first true technologists of Antiquity. He was a mathematician, mechanic and taught technical subjects in the prestigious Museum of Alexandria, probably in the mid-first century B.C. His biographical events are still the object of discussion.
The technical-scientific production of Hero of Alexandria is quite extensive. Besides, his treatise entitled Automata, which covers mechanics, wrote one on pneumatics called Pneumatica, which is among the best known. In the latter, Hero proposed devices and machines that he designed and revised and re-proposed inventions of other technologists of Antiquity. In this regard, it is worth noting its connection with the works of Vitruvius (De architectura).
The foundation of hydraulics by Archimedes (ca. 287 B.C. - 212 B.C.) led to the formulation and invention of several hydraulic devices and mechanisms, useful for different purposes. Moreover, the pump force invented by Ctesibius of Alexandria (ca. 285-222 B.C.) was described by Philon Byzantius in his treatise Pneumatica, and it is also included in Vitruvius. Therefore, one concludes that Hero, who lived most probably during the first century B.C., in some of his writings as in Pneumatica, deals with Hellenistic works preceding him by two or three centuries. The Pneumatics was, in all likelihood, a collection of Hero's texts written in Greek and gathered posthumously. It presents itself, in fact, as a compendium of the various ways in which air, water or steam can be used.
During the Renaissance, it had a wide diffusion, having much more impact than in Antiquity. The first Latin edition was published by the Italian F. Commandino, with the title Heronis Alexandrini Spiritalium liber, in 1575. The text was also printed eight years later in Paris and again in 1680 in Bologna. In addition to a Latin translation, several editions in Italian were published. Among the most important, there is undoubtedly the one made by the Italian architect interested in hydraulics, Giovanni Batista Aleotti. His translation was published in 1589 as Gli artificiosi, e curiose moti spiritali de Erone Alessandrino. It is a work that was not translated directly from the Greek but from the Latin edition of Commandino, and it became prevalent, being printed in 1647 in Bologna and 1693 in Paris.
In the Aleotti’s version of the treatise Pneumatica, the work was dedicated to the Italian nobleman and ecclesiastic D. Scipione Gonzaga (1542 – 1593). This edition includes an index or Tavola dei Theoremi, divided into 98 sections, the vernacular translation of Hero's introduction on the notion and nature of vacuum, and some of Aleotti's considerations, such as a commentary Aggiunta dell'Aleotti. This is followed by a series of descriptions accompanied by illustrations of devices powered primarily by heated air whose operation is based on the properties of liquids. The most famous is undoubtedly the Aeolipile – or the sphere of Aeolos – the ancestor of the steam engine (where it is shown how thermal energy can be converted into mechanical energy) and the fountain of Erone. In total, more than one hundred devices are presented.
The Pneumatica was translated for the first time into German in 1687. The original Greek edition reappeared in 1693 thanks to the work of the French Melchisédech Thévenot in Veterum mathematicorum opera, who also published Hero's Automata.
The edition of F. Commandino of 1575 is present at the Library of the University of Coimbra.