E.C. Marchant, Commentary on Thucydides Book 1

17. σεισμῶν τε πέρι ... ἡλίου τε ἐκλείψεις—the construction changes slightly. We might have had σεισμοί or περὶ ἐκλείψεων.

19. οἱ αὐτοί—moreover, emphasising ἰσχυρότατοι. Cf. the use of idem.

20. πυκνότεραι—of course Thuc. does not record all the strange things that befell μετὰ τοῦδε τοῦ πολέμου: e.g. he records no instances of αὐχμός or λιμός (for λιμοί evidently does not refer to hunger caused by siege). He records two eclipses of the sun, one in 431 B.C. (2.28), the other in 424 B.C. (4.52), but if the Ten Years' War be meant, three eclipses could have been observed in Greece; or it the Twenty-seven Years' War is alluded to, six. Of course it is not certain that all of the eclipses were actually observed; Thuc., as Mr. Forbes says, only gives the popular opinion.

παρὰ τά—as compared with; cf. 4.6 χειμὼν μείζων παρὰ τὴν καθεστηκυῖαν ὥραν.

23. καὶ ἡ ... ἡ νόσος—the art. is similarly repeated to throw emphasis on the second part of the phrase—the disease that ... I mean the pestilence—in c. 126. 4, and in several other instances. With νόσος most edd. supply ἐγένετο: but Steup rightly says οὐκ ἄπιστος κατέστη, for when Thuc. describes the plague in 2.47, he expressly says that ‘it was said that it had broken out in several other places previously’ to 430 B.C.

μέρος τι—object of φθείρασα, sc. τῆς Ἑλλάδος, a great number of the Greeks.