An attempt to "state more clearly what Thucydides' notes might have consisted of", this paper specifically deals with two points: the initial purpose of his chronology καγα θερη και χεμωνα&b.sigmav;, and the numerical notations he could have used for his purpose. Assuming the chronological scheme as coeval with the first page of his notebook, the author tries to suggest that the notes were in a sense close to the technical συγγραφη, contract and covenant, to substantiate the promises of Pericles' strategical forecasts. Pericles' strategy, to be recorded, needed special time-space coordinates, which Thucydides provides by his chronological schematization. With regard to the numerals, the writer in the end concludes, on the base of samples of epigraphical and textual evidences, that the bull-spelling of numerals was the only plausible way Thucydides could have written, the aerophonic system being locally limited and varied from city to city, and the alphabetic system coming into use in Athens, somewhat later than the time at which the History was written.