In the ninth century, the German organ-makers acquired great renown. The monk Gerbert, who, as we have already remarked, became pope under the name of Sylvester II., and co-operated so efficiently in the progress of the horological art, established in the monastery of which he was abbot a workshop for the manufacture of organs. We must add, that all the musical treatises written from the ninth to the twelfth century entered into very considerable details concerning the arrangement and working of this instrument. Nevertheless, the admission of the organ into churches did not fail to meet with earnest opponents among the bishops and priests of the day. But while some complained of the thunder and rumbling of the organs, others appealed to the examples of king David and the prophet Elisha. Finally, in the thirteenth century, the right of placing organs in all churches was no longer disputed, and the only question was, who could build the most powerful and most magnificent instruments. At Milan was an organ the pipes of which were of silver; at Venice some were made of pure gold. The number of these pipes was varied and multiplied to an infinite extent, according to the effects the instrument was required to produce. The mechanism was, generally speaking, rather complicated, and the working of the bellows very laborious. In large organs the key-board was made up of key-plates five or six inches wide, which the organist, his hands defended by thickly padded gloves, had to strike with his clenched fist in order to bring out the notes (Fig. 171). [Illustration: Fig. 171.--Organ with single Key-board of the Fourteenth Century. (Miniature from a Latin Psalter, No. 175, Bibl. Imp., Paris.)] The organ, which, as we have seen, was at first of a portable nature, in some cases resumed its original dimensions (Fig. 172). It was then sometimes called simply _portatif_ (hand-organ), and sometimes _régale_ or _positif_ (choir-organ). Raphael, in one of his famous pictures, represents St. Cecilia singing sacred hymns, and accompanying herself on a choir-organ. [Illustration: Fig. 172.--Portable Organ of the Fifteenth Century. (Miniature in Vincent de Beauvais’ “Miroir Historial,” MS. in the Bibl. Imp., Paris.)] The class of pulsatile instruments was formed of bells, cymbals, and drums. [Illustration: Fig. 173.--_Tintinnabulum_ or Hand-Bell of the Ninth Century. (Boulogne MS.)] [Illustration: Fig. 174.--The _Saufang_ of St. Cecilia’s at Cologne. (Sixth Century.)] [Illustration: Fig. 175.--Bell in a Tower of Siena. (Twelfth Century.)]