The dating of Hero of Alexandria has been linked with the lunar eclipse of March 13, ad 62, since Otto Neugebauer discovered that this eclipse is the only one that can fit the one described in Hero’s Dioptra 35. Although only a number of scholars claim that Hero himself observed the eclipse, almost all of them take Neugebauer’s identification for granted. We use statistical and linguistic methods to criticize this assumption: all indices we have found point to the fact that (...) the eclipse was merely invented as an example and, for that reason, that it cannot be used to determine Hero’s life span. (shrink)

Summary In his Theoremata de lumine, et umbre (1521), Francesco Maurolyco (1494–1575) discussed, inter alia, the problem of the pinhole camera. Maurolyco outlined a framework based on Euclidean geometry in which he applied the rectilinear propagation of light to the casting of shadow on a screen behind a pinhole. We limit our discussion to the problem of how the image behind an aperture is formed, and follow the way Maurolyco combined theory with instrument to solve the problem of the projection (...) of light through small apertures. We show that Maurolyco not only reformed the classical sources which, he thought, were no longer the authoritative code of textual knowledge, but also established with the dioptra a novel linkage of method, theory, and instrument. He thereby demonstrated the importance of optics to the science of astronomy. (shrink)