Charlemagne, who was proud of his thorough acquaintance with the liturgy, who esteemed it an honour to wear, on high occasions, the green chasuble embroidered with gold, and to chant the epistles before the assembled congregations, took the greatest pains with all the ceremonies of the Church; and it is an undoubted fact that the pomp with which they were afterwards celebrated was inaugurated by him. Charlemagne and his successors, Louis the Affable and Charles the Bald, did not, however, content themselves with merely attending to ceremonial pomp; they did their best to introduce a principle of unity in conformity with the Roman liturgy. At the commencement of the eighth century Pope Adrian I., having sent to Charlemagne an antiphonary scored by St. Gregory himself, the Emperor ordered all the churches in his dominions to adopt the Gregorian chant. Thenceforward the ancient Gallican liturgy almost disappeared, and when Charles the Bald was desirous of comparing together the Greek, Roman, and Gallican liturgies, he was obliged to summon ecclesiastics from Toledo to officiate in his presence according to the Gallican rite. Charles preferred the Roman ritual; but notwithstanding this, each diocesan cathedral, each separate abbey, introduced into the Gallo-Roman liturgy various accessory forms differing more or less from one another. It is possible to trace back to the sixth century the first use of church bells, but their general introduction into the Western church dates from the eighth century. They were termed _seings_ (in Latin _signa_); they were not rung, but were simply struck with wooden or metal hammers (Fig. 187), as is still done south of the Pyrenees. From this practice comes the word _toc-seing_ or _tocsin_, applied to the municipal peals of the Middle Ages and of still later times. The organ (_organum_) also dates from the eighth century. Imperfect as this instrument originally was, it caused tremendous enthusiasm among its hearers. Indeed, it may be said that organs and church bells had an equal share in raising the prestige of the ceremonial liturgy, which charmed and captivated both the senses and the souls of its hearers, by the display of its numerous officiating clergy, by the solemn gravity of its chants, by the noble simplicity of the vestments, and by the chaste and majestic arrangement of its ritual. [Illustration: Fig. 188.--The Triumph of the Lamb.--Christ, typified as the spotless lamb, with a glory round his head and holding the cross, is at the feet of God the Father; around him are the Four Evangelists, represented by their typical attributes, and resting upon wheels of fire. The archangels are bringing him their offerings. The firmament is supported by four angels. Beneath is St. John explaining the Apocalypse to his commentator.--From a Miniature in the “Commentary upon the Apocalypse,” by Beatus; a Manuscript of the Twelfth Century, in the Collection of M. Ambroise Firmin-Didot.]