Stichometry: Costs of Professional Writing Measured by the Normal Length of a Line in a Verse of Virgil

"At the time of the conversion to Christianity, Rome had twenty-eight libraries within its walls and book production was so well established a line of business that Diocletian, in his price edict [Edict on Maximum Prices (also known as the Edict on Prices or the Edict of Diocletian; in Latin Edictum De Pretiis Rerum Venalium)] set rates for various qualities of script: for one hundred lines in 'scriptura optima', twenty-five denarii; for somewhat lesser script, twenty denarii, and for functional script ('scriptura libelii bel tabularum'), ten denarii. The unit of valuation was the normal length of line in a verse of Virgil [Vergil]. The extent of a work is given in these units at the end of some manuscripts (stichometry), and stichometric lists survive for biblical books and for the writings of Cyprian" (Bischoff, Latin Palaeography: Antiquity and the Middle Ages [1990] 182).

Laufer, Diokletians Preisedikt (1971).