From the Middle Ages up to the 18th century, European (noncirculating) libraries literally chained their books to heavy wooden shelves to keep them from walking out of the library with an overzealous scholar. Images of such libraries are striking: books lined up with their spines facing in, foredges out, with loops of chain draping gracefully to the ground.
One end of the chain is attached to the front cover of each book, and the other slotted onto a rod running along the bottom of each shelf, with enough play in the chain to allow a book to be taken from the shelf and read at a nearby desk. Hereford Cathedral's 17th century chained library is the largest to survive with all its chains, rods and locks intact.
legbagede says: the poor tomes themselves were referred to as the
cantenati...the Chained. So sad.