There is no direct evidence of the time or place when this Dialogue is supposed to take place, nor of the date of its composition. Much of the matter is common to it with the Dialogue _On the cessation of the Oracles_, one passage of which has been thought (by Adler) to be an extract from it. Lamprias takes the principal place in both, and Plutarch is not present, at least under his own name. The solar eclipse mentioned in c. 19 as recent would give a clue if it could be identified. Ginzel (_Spezieller Kanon_) has selected three for special consideration, viz., those of April 30, A.D. 59, March 20, A.D. 71, and January 5, A.D. 75. By the kindness of J. K. Fotheringham, Esq., D.Litt., Fellow of Magdalen College, who has made the laborious computation, I am able to state the respective magnitude of these eclipses at Chaeroneia as 11·08, 11·82, 10·38 (totality = 12). Thus Ginzel’s preference for No. 2 is confirmed; it was there a large partial eclipse, and the time of greatest phase was 11 hours 4·1 minutes local solar time. Several stars would become visible, 66/67 of the sun’s diameter being obscured; a few might be visible during No. 1, none during No. 3. PERSONS OF THE DIALOGUE 1. SEXTIUS SYLLA, the Carthaginian, mentioned in the _Life of Romulus_ (c. 15) as ‘a man wanting neither learning nor ingenuity’, who had supplied Plutarch with a piece of archaeological information. Elsewhere (_De cohib. ira_, c. 1) he is addressed as ‘O most eager Sylla!’ In another Dialogue he declines to be led into a discussion on all cosmology by answering the question ‘whether the egg or the bird comes first?’ (_Sympos._ 2, 3). He has a story, or myth, to tell about the moon, which he is impatient to begin. This story, which he had heard from a friend in Carthage, is mainly geographical in interest. The details remind us of those quoted from Pytheas about his journeys to Britain and the Northern Seas. The whole conception of the globe is clearly earlier than that of Ptolemy (see especially as to the Caspian Sea, c. 26). The myth also introduces us to the worship of Cronus as practised at Carthage, and connects it with the wonders of the moon, and her place in the heavenly system. In c. 17 SYLLA raises a good point, about the half-moon, which was being passed over. 2. LAMPRIAS, a brother, probably an elder brother, of Plutarch directs the course of the conversation, and himself expounds the Academic view, referring to Lucius for his recollections of a recent discussion at which both had been present, when the Stoic doctrines on physics had been criticized. In some of the Symposiacs and other dialogues Lamprias takes a similar place; in others both brothers take part. Lamprias probably died early.