Complete Extant Works of Hero of Alexandria, Vol. 2

XVI

INTRODUCTION.

In addition to these four books, the Fihrist knows of another, namely:
5. The Book on Things that Move by Themselves, by Hero. I, p. 285.

The next source is the Biographical Dictionary of the Vizier Gemâl ed-Dîn al-Kiftī, who lived from 1172 to 1248. He used the Fihrist heavily and mentions Hero in two places: once with Euclid's Elements, stating that he solved the doubts of the book (cf. Casiri I, 341); the second time in a small special article where he says (H. Kh. VII, 611): The Greek Hero of Alexandria in Egypt is a scholar in the sciences of the people of his time. He wrote books, taught, and provided clarification on the secrets of this art. His writings include the Book of the Solution of Doubts in the Book of Euclid and the Book of Pneumatic Machines.

The third, albeit very late, source is the "Lexicon bibliographicum" of Hadji Khalfa (died 1658), ed. Flügel. It mentions Hero in three places:
1. I, 383, under Euclid's Elements with the words: Hero authored the solution of the doubts therein.
2. II, 589. Science of pulling/lifting loads. This is the science in which one investigates how to employ tools to pull heavy objects with a small amount of force. Its utility is obvious; Hero has provided proof in his book on this science for the lifting of 100,000 pounds by a force of 500 pounds. It is a branch of mathematics. The Imam gave proofs for some questions of the same at the end of the "Uniter of Sciences," while the author of the "Key to Felicity" (Taşköprizadeh) mentions no book on this branch of science.
3. V, 48. Book of War Machines by Hârûn (Hero?), which Takîj ed-Dîn cites in the "Lotus Tree of the Boundary."