Medieval app

I have a new enthusiasm for volvelles (and yet another suspicion that I would have made a happy medievalist).

A volvelle is a paper thing made of moveable layers, or more exactly, several circular sheets of  different sizes, mounted together so that the new alignments that appear with each turn bring different bits of information together.  They expose one specific meaning, single it out and bring it forward out of all the hundreds or thousands of potential meanings that are contained in the object.  And the object is part of a book: the base sheet, with the largest circle, is a page bound in to the spine along with the others.

Volvelles accompanied the long, uneven transition from manuscript, or scribal culture to print culture. In fact they seem to chafe a bit against the limitations of a book proper, as in, a stack of loose paper sheets bound together, with text and images, exuding authority and order, notably from one page to the next, from front cover to back cover.

But volvelles resist: they flourished around 1400, that is, just as populations were gradually  making the complicated adjustments that would underpin print culture (the book is widely assumed to be the first industrial product). Perhaps the most striking resistance is their mathematical, rather than  alphabetical context: if you’re reading along and you come to a volvelle (often on a separate page, but not necessarily), you must stop and reorient yourself. The volvelle doesn’t flow with text. Defining its own terms, parameters, weights, layers, it calculates and  combines — a tiny, human-scaled computer.