An unsatisfactory English translation of the Almagest by TaliaferroR. C. is included in vol. xvi of the Britannica Great Books series (1952); Pedersen refers exclusively to Heiberg's Greek text and Manitius's German translation (the best available modern version).
2.
It is often asserted that Ptolemy was an inferior observer, but a careful reading of the text does not support this position. The best study of the errors in Ptolemy's observations is to be found in an unpublished dissertation by BrittonJ. P., “On the Quality of Solar and Lunar Observations and Parameters in Ptolemy's Almagest”, Yale, 1967 (not in Pedersen's bibliography). By a thorough analysis of the ancient data Britton has shown, for example, that the times of lunar eclipses were observed with about the same accuracy by Ptolemy and his predecessors, i.e. a probable error of about ±15 minutes for the observed time of a phase of an eclipse (Britton, p. 101). Moreover, in comparing the three observations by Hipparchus of the Moon's elongation from the Sun with modern theory, Britton found an average error of 29·6 minutes in longitude, whereas for Ptolemy's three observations of the Moon's elongation from the Sun and Regulus he found an average error of 26·6 minutes; i.e. in no sense can Hipparchus's observations of elongations be considered superior to those made by Ptolemy (Britton, p. 151). Pedersen has specifically excluded instrumental and observational errors from his discussion (p. 9).
