Hero in Harpers Dictionary of Classical Antiquities (1898)

1. A native of Alexandria and disciple of Ctesibius, who flourished about B.C. 125. He placed engineering and land-surveying on a scientific basis, and was celebrated as a mechanician, and invented the hydraulic clock, the machine called "the fountain of Hero ," and a forcing-pump used as a fire-engine. (See Ctesibica Machina.) He enjoyed a high reputation, and is mentioned by Gregory Nazianzen with Euclid and Ptolemy. He is now, however, principally known by some remains of his writings on mechanics. His extant writings are: (a) "On the Machine Called the Chiroballistra" (Χειροβαλλίστρας κατασκευὴ καὶ συμμετρία); (b) "Barulcus" (Βαροῦλκος), a treatise on the raising of heavy weights, which is mentioned by Pappus, and was found by Golius in Arabic; (c） "Belopoeica" (Βελοποιϊκά), a treatise on the manufacture of darts; (d) "On Pneumatic Machines" (Πνευματικά). In this work is the first and only notice among the ancient writers of the application of steam as a moving power. There is an English translation by Greenwood (London, 1851). (e) "On the Construction of Automata" (Περὶ Αὐτοματοποιητικῶν), contained in the Math. Veteres; it describes a number of small machines and mechanical toys. (f) "On Dioptrics," from which Heliodorus, a mathematician who flourished after the commencement of the Christian era, has left an extract. (g) Μετρικά, consisting of geometrical and trigonometrical problems and solutions. Other works of Hero , now lost, are mentioned by Pappus, Eutocius, Heliodorus, etc. Hero describes the theodolite, the cyclometer, and the steam-engine; and discusses the centre of gravity. His works have been edited by F. Hultsch (Berlin, 1864). See the treatise on Hero by T. H. Martin (Paris, 1854); and the account in Ball's Short History of Mathematics (London, 1888). 2. Of Constantinople, commonly called the Younger, who is supposed to have flourished about A.D. 900. In a work attributed to him (on Geodesy), he states that the precession of the equinoxes had produced seven degrees of effect since the time of Ptolemy, so that he must have been about 500 years later than Ptolemy. The writings of Hero the Younger relate to warlike machines, tactics, and practical geometry. 3. A mathematician, who flourished about the middle of the fifth century. 4. (Myth) (Ἡρώ). See Leander.