Complete Extant Works of Hero of Alexandria, Vol. 3

At the beginning of the 15th century, the Constantinopolitan book was handled by two learned men—one (hand 2) using a larger and more negligent style of writing, the other (hand 3) a smaller and more diligent one. It was treated in such a way that many scholia marginal notes or commentaries were added, and some light attempts at correction were made to fill in gaps and remove the most obvious errors. While much of this was done correctly, many equally obvious errors were left behind. Some corrections are of a type that creates a false appearance of integrity in a mutilated text. Since there is much in these that could only have been derived from conjecture—and faulty conjecture at that—I deny that those correctors had any other codices of Hero's work at hand beyond what could be found by such conjecture. Furthermore, some of those scholia, which I shall publish hereafter, were obscured so thoroughly by faded ink that even with the most intense focus of the eyes, I could not read them: but Joannes Ludovicus Heiberg could. This same illustrious man was also unwilling to deny me his assistance in other parts of this codex, for which favor I feel most deeply indebted.

If it is true—and it certainly is—that the Pneumatica treatise on air pressure, Automatopoetica treatise on automatons, Belopoetica treatise on artillery/missile weapons, and Dioptrica treatise on surveying and the dioptra can be safely attributed to Hero of Alexandria, the books on measurement certainly bear such a resemblance to them in their style of speaking, arguing, and introducing that they could not have been composed by any other man. As long as these were considered lost, they were argued over with such intense disagreement among learned men as is natural in a very obscure question, where the testimony of authors is not sufficient to reach a certain judgment.1) See Eutocius in Archimedes' Measurement of a Circle, Vol. III, p. 270, Heiberg. Now that the work, of which almost all memory had vanished save for the title, has emerged from long oblivion, the controversy is easily decided. It is therefore apparent that those who erred are they who...