Rozier chances upon the labor-saving idea of producing catalogs according to Gessner ’ s procedures — that is, transferring titles onto one side of a piece of paper before copying them into tabular form. Yet he optimizes this process by dint of a small refi nement, with regard to the paper itself: instead of copying data onto specially cut octavo sheets, he uses uniformly and precisely cut paper whose ordinary purpose obeys the contingent pleasure of being shuffl ed, ordered, and exchanged: “ cartes à jouer. ” 35 In sticking strictly to the playing card sizes available in prerevolutionary France (either 83 × 43 mm or 70 × 43 mm), Rozier cast his bibliographical specifi cations into a standardized and therefore easily handled format.

Through an inner structure of recursive links and semantic pointers, a card index achieves a proper autonomy; it behaves as a ‘communication partner’ who can recommend unexpected associations among different ideas. I suggest that in this respect pre-adaptive advances took root in early modern Europe, and that this basic requisite for information pro-cessing machines was formulated largely by the keyword ‘order’.

Here, I also briefl y digress and examine two coinciding addressing logics: In the same decade and in the same town, the origin of the card index cooccurs with the invention of the house number. This establishes the possibility of abstract representation of (and controlled access to) both texts and inhabitants.

What differs here from other data storage (as in the medium of the codex book) is a simple and obvious principle: information is available on separate, uniform, and mobile carriers and can be further arranged and processed according to strict systems of order.

s Alan Turing proved only years later, these machines merely need (1) a (theoretically infi nite) partitioned paper tape, (2) a writing and reading head, and (3) an exact

“ Card catalogs can do anything ” — this is the slogan Fortschritt GmbH

on advocate for the index card in the early twentieth century called for animitation of “accountants of the modern schoolY”1

In 1780, two years after Linnaeus’s death, Vienna’s Court Library introduced a card catalog, the first of its kind. Describing all the books on the library’s shelves in one ordered system, it relied on a simple, flexible tool: paper slips. Around the same time that the library catalog appeared, says Krajewski, Europeans adopted banknotes as a universal medium of exchange. He believes this wasn’t a historical coincidence. Banknotes, like bibliographical slips of paper and the books they referred to, were material, representational, and mobile. Perhaps Linnaeus took the same mental leap from “free-floating banknotes” to “little paper slips” (or vice versa).