Technical chronology establishes the structure of calendars and the dates of events; it is, as it were, the foundation of history, particularly ancient history. The chronologer must know enough philology to interpret texts and enough astronomy to compute the dates of celestial phenomena, above all eclipses, which alone provide absolute dates. Joseph Scaliger, so we are told, was the first to master and apply this range of technical skills:
Of the mathematical principles on which the calculation of periods rests, the philologians understood nothing. The astronomers, on their side, had not yet undertaken to apply their data to the records of ancient times. Scaliger was the first of the philologians who made use of the improved astronomy of the sixteenth century to get a scientific basis for historical chronology.
So Mark Pattison.
This verdict can be challenged on a number of grounds. The one relevant at present is simple: Scaliger himself claimed far less. He certainly said that technical chronology had been untouched in modern times — not an entirely fair judgement — but in antiquity it had been practised in exactly the manner he considered proper, or so he believed. In particular he singles out Censorinus, whose De die natali drew extensively on Varro's lost Antiquitates rerum humanarum, books 14–19, for information on chronology.
Students of Varro have long appreciated the importance of Censorinus. His dry and compact treatise offers Varronian views on etymology, the human life-span, and the course of history itself, all couched in language so jejune as to suggest that he added little or nothing to what he read.