Probatoria

Two centuries before printing was invented, big libraries of manuscript codices were to be found in university colleges, city halls, and noble palaces, as well as in monasteries and cathedrals. All those libraries had to keep their books chained to the shelves, they were so expensive. But university colleges also had to have many books unchained, so that their students could borrow them and study them for a year at a time in their rooms.

And how to secure those borrowed books? You could inscribe them, for example, “This book belongs to Oriel College, and whoever steals it is eternally damned.” But we have seen books with such terrifying inscriptions, only the owner’s name scraped off and a new one written in. Or the whole curse erased. Or the whole curse intact, and the book in Scotland.

At the end of the thirteenth century the greatest college lending library was that of the Collège de Sorbonne in Paris. Most of the books that the Sorbonne scholars could borrow for long terms are still in Paris, and here is why. The job description for the college librarian included these words:

When you are recording the loan of a book, it is not enough to write, 'John of Senlis has the book The City of God, worth 6 livres, or whatever,' without also writing in the register, 'it begins on the second folio thus and so,' lest fraud occur in exchanging a book of greater price for a book of the same kind but lesser price or, if one should be lost, a worse one be returned.

You see how clever that trick was. Different copies of the City of God would have different quantities of text on pages one and two, and so the second folio, page three, would start with a different phrase of that great work of Augustine, and if the student John of Senlis came in at the end of term with a book that had other words in that place, he would have some expensive explaining to do. The second-folio incipit was a book’s fingerprint, once it was recorded in the library catalogue or lending records. Any unchained library or wealthy book owner could use the method, and within a few years it was in use all over southern Europe. The library records of the popes at Avignon used it, likewise the Louvre Library of the French kings. The custom spread to the English churches and colleges.

Obviously, a Sorbonne book that survives whole today in the Bibliothèque Nationale will still have the same second-folio fingerprint. It struck Dan that he could do a lot of tracing of books over the centuries if he kept a index of those little fingerprints, and in 1969 he started doing just that. The file of paper slips grew and grew, then they invented the 80-column IBM card to make the work faster, then the personal computer and personal database systems.

We have collected every pre-modern second-folio record they could find. Today We have some 40 thousand of them in a digital spreadsheet. To make that index of old records really useful, we have collected in a parallel database second folio readings from all the codices we have examined, and all the second folio readings that have appeared in modern catalogues.