It was the custom of the Greeks and Romans to estimate the length of their literary works by measured lines. In poetical works the number of metrical verses was computed; in prose works a standard line had to be taken, for no two scribes would naturally write lines of the same length. On the authority of Galen (de Placit. Hipp. et Plat. Viii. I) we learn that the unit of measurement among the Greeks was the average Homeric line, consisting of about 36 letters, or 16 syllables. The lines so measured were called στιχοι, or επη.
The practice of thus computing the length of a work can be traced back to the 4th century BC in the boast of Theopompus that he had written more επη than any other writer. The number of such στιχοι or επη contained in a papyrus roll was recorded at the end of the work; and at the end of a large work extending to several rolls the grand total was given. The object of such stichometrical calculations was a commercial one, viz. to assess the pay of the scribe and the market value of the manuscript.
Callimachus, when he drew up his catalogue of the Alexandrian libraries in the 3rd century BC, registered the total of the στιχοι in each work. Although he is generally lauded for thus carefully recording the numbers and setting an example to all who should follow him, it has been suggested that this very act was the cause of their general disappearance from manuscripts; for that, when his πινακες were published, scribes evidently thought it was needless to repeat what could be found there; and thus it is that so few manuscripts have descended to us which are marked in this way. A more natural reason for the scarcity of such details is that scribes and booksellers suppressed them in order to impose upon their customers.
The application of the system to Latin manuscripts was fully recognized. The unit of measurement was the average Virgilian line. This is recorded in an interesting memorandum written in the 4th century, found in a manuscript in the Phillipps Library at Cheltenham, containing a computation of the στιχοι in the books of the Bible and the works of Cyprian. The writer states that in the city of Rome it had become the practice not to record the number of verses in the manuscripts, and that elsewhere also, for greed of gain, the numbers were suppressed. Therefore he has made a calculation of the contents of the text under his hand and has appended to the several books the number of Virgilian hexameters which would represent its length. The rate of pay of the scribes in Diocletian's reign was fixed by his edict de pretiis rerum venalium at 25 denarii for 100 στιχοι in writing of the first quality, and at 20 denarii for the second quality; what the difference was between the two qualities does not appear.
The system of measurement described above has been called "total stichometry," in distinction from "partial stichometry," which was the calculation and marking off in the margins of the στιχοι from point to point, just as we mark off the lines in a poem at convenient intervals and number the verses of the chapters of the Bible. This method was for convenience of literary reference. Instances of such "partial stichometry" are not very numerous among existing manuscripts, but they are sufficient to show that the system was in vogue. In the Bankes Homer in the British Museum the verses are numbered in the margin by hundreds, and the same practice was followed in other Homeric papyri.
In the Ambrosian Pentateuch of the 5th century at Milan the book of Deuteronomy is likewise numbered at every hundredth στιχος. Euthalius, a deacon of Alexandria of the 5th century, marked the στιχοι of the Pauline epistles by fifties. In the Codex Urbinus of Isocrates, and in the Clarke Plato of AD 888, at Oxford, there are indications of partial stichometry.
There was also in use in biblical texts and in rhetorical works a stichometrical system different from that described above, in which the στιχοι, as we have seen, were lines of measurement or space-lines. This other system, which is more correctly entitled colometry, consisted in the division or breaking up of the text into short sentences or lines according to the sense, with a view to a better understanding of the meaning and a better delivery in public reading. The Psalms, Proverbs and other poetical books were anciently thus written, and hence received the title of βιβλοι στικηρεις, or στικηραι; and it was on the same plan that St Jerome wrote, first the books of the prophets, and subsequently all the Bible of his version, per cola et commata "quod in Demosthene et Tullio solet fieri." In the Greek Testament also Euthalius, in the 5th century, introduced the method of writing 0-rixrt6ov, as he termed it, into the Pauline and Catholic epistles and the Acts. The surviving manuscripts which contain the text written in short sentences show by the diversity of the latter that the rhythmical sentences or lines of sense were differently calculated by different writers; but the original arrangement of St Jerome is thought to be represented in the Codex Amiatinus at Florence, and that of Euthalius in the Codex Claromontanus at Paris. With regard to St Jerome's reference to the division per cola et commata of the rhetorical works of Demosthenes and Cicero, it should be noticed that there are still in existence manuscripts of works of the latter in which the text is thus written, one of them being a volume of the Tusculans and the De senectute in the Bibliothèque Nationale at Paris. The same arrangement of the text of the orations of Demosthenes is also mentioned by the rhetoricians of the 5th and subsequent centuries.