A jewelled ring was always worn by a bishop, and was an essential part of his costume when pontificating. It was specially made for him, and usually went with him to the grave. Hence it happens that many of these rings have survived, and are preserved both in museums--the collection in the Franks Bequest in the British Museum being the most extensive--and in the cathedrals where they have been found.[100] In the earliest times bishops usually wore engraved rings for use as signets, but they seem to have had a large jewelled one as well for ceremonial use. According to the instructions of Pope Innocent III in 1194, the episcopal ring was to be of solid gold set with a precious stone on which nothing was to be cut; hence the thirteenth-century rings are at times somewhat rudely fashioned, with the shape of the bezel adapted to the gem just as it was found, its surface merely being polished. Among the stones usually chosen for the purpose were the ruby indicating glory, the sapphire purity, the emerald tranquillity and happiness, and crystal simplicity. Antique gems in earlier times were also worn, and on some rings an inscription is added to give a Christian name to the pagan figure; but others were merely regarded as ornaments without meaning, like one dating from the twelfth century in the Waterton Collection, which bears a Roman cameo in plasma of a female head in high relief; or like the curious example found in the coffin of Seffrid, Bishop of Chichester (d. 1151), in which is mounted a Gnostic intaglio. The most usual form of ring, and one which seems to have been reserved chiefly for bishops, is of a pointed or stirrup shape. It is commonly found set with a small sapphire, more rarely with an emerald, and sometimes, as in William of Wykeham's ring at New College, with a ruby (Pl. XXIII, 1). The fashion for this type appears to have lasted from the thirteenth to the fifteenth century. [100] Amongst others there are three in each of the cathedrals of Chichester, York, Winchester, and Durham, and two at Hereford (_Archæologia_, XLV, p. 404). [Illustration: _PLATE XXIII_ MEDIÆVAL AND LATER RINGS] The episcopal ring was formerly worn on the right hand, but is placed at the present day upon the annular finger--the third finger of the left hand. Not more than one episcopal ring is now worn, but on sepulchral effigies and early pictures bishops are represented with three or four rings on the right hand, not infrequently upon the second joint of the fingers, and also upon the thumb. They were generally worn over the gloves, the backs of which were ornamented in addition with a large jewel. These rings were often, therefore, of considerable size, so that when worn without a glove a guard-ring was necessary to prevent their falling off.[101] Mitred abbots were allowed to wear the ring; by others it might be worn, but not during the celebration of the Mass. The use of a ring was forbidden to the lower clergy.