Collector Walter Seldon catalogued his pamphlets on the backs of used envelopes. He cut them to a common height, wrote a title across the plainest part and kept them upright in two narrow boxes. The addresses on the reverse belonged to an earlier purpose and had little bearing on the order in which the cards were filed.
The system began as an economy. Blank card cost money, while envelopes arrived with the daily post. Its advantage soon became flexibility. A pamphlet could be placed under a new subject without requiring a page to be recopied, and a long description could occupy two cards held together with a small paper clip.
Seldon's subjects were practical rather than consistent. Drainage sat beside gardening; local walks shared a division with old boundaries. A reader looking for one topic might need to follow several handwritten references. These crossings were important because they described the collector's understanding of relationships between things that a single alphabetical list would have kept apart.
His niece Bera later added a cleaner author index. She resisted replacing the earlier catalogue altogether, since its familiar headings were still useful to visitors who had learned them. The two systems coexisted. A printed name offered one route into the collection; a remembered subject offered another.
The envelopes therefore preserved more than titles. Their altered corners and repeated references show a collection becoming accessible through use. Order was not something imposed once and then maintained untouched. It was a succession of decisions made by people trying to find a particular thin booklet among shelves of objects that looked remarkably alike.