As time went on, crucifixes, statuettes, triptychs, diptychs, and other portable helps to private devotion were made in ivory in great quantity; a consequence probably of the repeated travels of men to the east during the crusades. The term triptych for religious tablets composed of a centre piece and of one wing on each side, sufficient in width when folded to cover the centre, is commonly used in the description of various collections of ivories, because, whether or not exactly right, it is perfectly well understood and fully explains itself. Indeed, although triptych or pentaptych or polyptych may, in strictness and in its first signification, mean only (as it might happen) three or five or many leaves fastened together on one side by hinges or threads like the leaves of a book, yet the name triptych may be fairly applied to tablets, two of which hinge on the outside edges of the opposite sides of the third, and are intended to fold across and cover it. Where these wings are made, in order to surround the centre, of more than two pieces (and in such cases they generally inclose and protect also some larger carving or a statuette) the name shrine seems to be more appropriate and better to describe the object. Triptychs are spoken of more than once by Anastasius, the author of the Liber Pontificalis. For example, in his life of pope Hadrian, A.D. 772, he mentions one which had in the centre the face of our Saviour, and on each wing images of angels. It is greatly to be regretted that Anastasius is so miserably concise in his description of the marvellous works of art which he enumerates. We look in vain for any details or for the name of a single artist. The use of ivory in the middle ages, from the eighth to the beginning of the sixteenth century, was not confined to church and pious purposes. It was adopted for numberless things of common life. Not for common people perhaps, because its value and rarity were too great; but for the daily use of wealthy persons. Caskets and coffers, horns, hilts of weapons, mirror cases, toilet combs, writing-tablets, book-covers, chessmen and draughtsmen, were either made entirely of ivory, walrus and elephant, or were largely inlaid and ornamented with it. Examples of works of each of these kinds are to be found in the South Kensington museum; and with regard to some of them it is necessary to make a few remarks.