Heron
3. The younger, so called because we have not even an adjective of place to distinguish him from Heron of Alexandria, is supposed to have lived under Heraclius (A. D. 610-641). In his own work on Geodesy (a term used in the sense of practical geometry), he says that in his own time the stars had altered their longitudes by seven degrees since the time of Ptolemy: from which the above date must have been framed. But if he spoke, as is likely enough, from Ptolemy's value of the precession of the equinoxes, without observing the stars himself, he must have been about two hundred years later. He was a Christian.
Works
The writings attributed to Heron the younger are,--
1. De Machinis bellicis
There is one Greek manuscript at Bologna.
Editions
Published (Lat.) by Barocius, Venice, 1572, 4to.
2. Geodaesia
Montucla notices this as the first treatise in which the mode of finding the area of a triangle by means of its sides occurs. Savile, who had a manuscript of this treatise, rejects with scorn the idea of its having been written by Heron; but we suspect that he supposed it to be attributed to Heron of Alexandria.
Editions
published (Lat.) with the above by Barocius.
3. De Obsidione repellenda, ὅπως χρὴ τὸνν τῆς πολιορκουμένης τόλεως στρατηγὸν πρὸς τὴν πολιορκίαν ἀντιτάσσεσθυι
Editions
Published (Gr.) in the Veter. Mathemat. Opera, &c. mentioned in the life of Heron of Alexandria.
4. Παρεκβολαὶ ἐκ τῶν στρατηγικῶν παρατάξεων, &c
This exists only in manuscript.
5. Ἐκ τῶν τοῦ Ἥρωνος περὶ τῶν τῆς Γεωμετρίας καὶ Στερεωμετρίας ὀνουάτων
Editions
Published (Gr. Lat.) with the first book of Euclid, by Dasypodius, Strasburg, 1571, 8vo.
6. Excerpta de Mensuris
Editions
(Gr. Lat.), in the Analecta Graeca of the Benedictines, vol. i. Paris, 1688, 4to.
7. Εἰσαγωγὴ τῶν γεωμετρουμένων
This work exists only in manuscript.
Further Information
Fabric. Bibl. Graec. vol. iv. p. 237; Heilbronner, Hist. Mathes. Univ.; Montucla, Hist. des Mathém. vol. i.
From William Smith (ed.), Dictionary of Greek and Roman Biography and Mythology. Text provided under a CC BY-SA license by Perseus Digital Library, http://www.perseus.tufts.edu, with funding from the National Endowment for the Humanities and Tufts University. Data accessed from https://github.com/PerseusDL/canonical-pdlrefwk/ on 17 October 2026.