The most curious of all curious things thus recovered in this wonderful manner were the clay-books of Nineveh, consisting of sets of tablets covered with very small letters. The tablets were all oblong in shape, and when several of them were used for one book, the first line of the tablet following was written at the end of the one preceding it. The writing was done when the clay of the tablet was soft; was then baked to harden it, and the tablets were fastened together with rings. Thus was taken the first step toward the production of books. At the time the Assyrians were baking their records and bindings in the oven, the old Egyptians used strips of papyrus, pasted together in a continuous roll.
Later on, these rolls were cut into pieces, pasted behind each other, and fastened to a hollow tube of wood or ivory, around which they were then rolled and placed in capsules bearing the inscription of the contents. The Persians used the hides of animals on which to write; the Romans used tablets made from wood and covered with wax on which they wrote by means of a style. If two of these tablets were fastened together, they were known by the name of diptych, three of them triptych, or more of them in a bunch, polyptych. After a while ornamental covers were devised for these tablets.
Ivory and precious metals were used for the purpose. The ivory was carved, the gold and silver hammered, driven, chiseled and ornamented with pearls and precious gems. Over a thousand years had leaped into the abyss of eternity between the production of the crudely baked clay tablets of the Assyrian priest and the luxurious ivory-carved and silver, and gold-chased diptych of the ancient Roman; and the bookbinder became a possibility. With the advent and the growth of Christianity, the art of making books received a more powerful stimulus through the protectorate of the church. Monasteries were founded; learned men dedicated their lives to the embellishment of the books proper, as well as to their binding.