The curious custom of fastening books to their shelves by means of chains was common enough in Europe in mediæval times and became almost universal in the sixteenth and seventeenth centuries in churches. It was of course done as a safeguard against thieves, and as far as I know only in the case of printed books. Although printed books soon became plentiful, yet no doubt in the case of Bibles and Prayer Books it is likely enough that a considerable leakage took place. Such small books were commonly chained to the backs of the pews in private chapels throughout England, and undoubtedly the custom, though inconvenient in use, was effective enough for its purpose. Larger books would naturally belong to important libraries, those of cathedrals and churches particularly, and of these there are still left plenty of examples still in chains. The chains are of iron, average 3 feet long, and are clamped to the front edge of the upper board by means of a rivet; the other end of the chain is provided with a ring which runs freely to and fro along a locked metal rod. Enough play is given by the chain to allow of the book being taken off its shelf and rested on the desk close at hand which is always provided for it. There is a certain fashion in the way of attaching these chains. In foreign books the fastening is usually found at the top of the upper board, while in the case of English books it is usually fixed on the front edge of the upper board. The books were normally kept with their forages outwards, and on these edges the titles were written or emblazoned. The Laurentian Library at Florence has a large number of chained books kept in beautifully carved shelves. The Church of St. Wallberg in Zutphen has several chained books. There is a legend that the devil carried off so many of the holy books that something had to be done, so the chains were blessed in due form with holy water, since when the books have been safely preserved. Plenty of examples of chained libraries are still left in England, particularly at Hereford Cathedral, the old treasure house at Wimborne Minster and All Saints’ Church at Hereford; a complete list of them is given in Blades’ “Books in Chains,” published in London in 1892. The inconvenience of chains must have been considerable, and no doubt careless readers often got into trouble about them. On a notice concerning the library at King’s College, Cambridge, in 1683, readers are requested to replace the volumes “decently without entangling the chains.” About the middle of the eighteenth century the inconvenience of chains on books was fully realised, and from that time there has been a general tendency to their removal, except in cases where their retention is advisable for antiquarian reasons. True horn books were used in England and America, but similar constructions also existed in other countries--chiefly France, Germany, Italy, and Holland--but without horn covering.