1 The Birth of Science - MSRI

242 10. Lost Science
of most help, such as fine engravers and jewelers, 31 and the very rich. Nero
and his famous emerald monocle may be a case in point. 32 Moreover the
lack of literary references to magnifiers may to some extent derive from page 301
the beliefs of modern scholars: a person convinced that something did not
exist in Antiquity cannot but misunderstand any passage mentioning that
thing. Thus, Alcaeus wrote that wine is a man’s dioptron. 33 He probably
meant that drink as it were magnifies a person’s behavioral traits, putting
them in evidence, 34 but the belief that lenses were unknown has caused
dioptron to be translated as “mirror”, sacrificing both the general sense of
the passage and the natural meaning of the word, which on etymological
grounds can be presumed to mean something that is seen through (whereas
a mirror is katoptron). Strabo uses the same word to refer to chunks of a
transparent mineral that were exported from a certain place in Asia Minor.
36
While the ancient use of lenses for lighting fires is certain and that of
magnifying glasses seems at least very probable, few have been willing to
entertain the possible existence of telescopes in Antiquity. But, if nothing
else, this hypothesis would explain the many written and pictorial medieval
references to an object that supposedly would not be invented for
several centuries yet! 37 As more direct evidence we may cite a passage in
Strabo mentioning “reeds” or “tubes” by means of which images can be
magnified thanks to the refraction of visual rays, 38 and perhaps also one in
Geminus explaining that experts in geodesy, who used the dioptra, based
some of their work on the phenomenon of refraction. 39
31 Already in the eighteenth century the jewelry carver Johann Natter, based on his study of ancient
techniques, became convinced that his ancient colleagues could not have carried out all of
their work with the naked eye; see [Natter]. The same opinion is held today by several scholars
based on an analysis of gold craftmanship, particularly in the Roman period; see [Sines, Sakellarakis].
32 Pliny, Naturalis historia, XXXVII, 64. This continues a passage where Pliny mentions that engravers
used emeralds to lessen eye-strain and provide bigger images; but Pliny believed that the
engravers rested their eyes by contemplating the emeralds and that the enlarged images were those
of the emeralds themselves.
33 (Alcaeus, fr. 333 Vogt).
34 I am indebted to Bruno Gentili for this observation.
36 Strabo, Geography, XII, ii, 10.
37 See page 306.
38 Strabo, Geography, III, i, 5. Many editors have adopted Voss’s emendation of (reeds) into
(glass pieces), thus admitting the existence of magnifying glasses but perhaps missing the
full import of the passage.
39 [Heron: OO], IV, 100, 17–18. The Greek term used, ©, is usually rendered as “reflection”,
but there are several passages where “refraction” must be meant: for example, Sextus Empiricus,
Adversus mathematicos, V, 82. The word is derived from a verb meaning “break” and was
presumably used for either phenomenon where light rays are “broken” (change direction).
Revision: 1.11 Date: 2003/01/06 02:20:46