During the rule of the Arabs in Northern Africa and in Spain, thousands of manuscripts were gathered together in their chief cities, such as Cairo and Cordova, and many Arabic-Spanish and Moorish writings have been preserved in the Escurial Library, though a large part of this library was burnt in 1671. With these exceptions, the collections of books belonging to the various religious houses were practically the only libraries of early mediæval times. These collections, to begin with, were very small; so small, indeed, that there was no need to set apart a special room for them. Library buildings were not erected till the fourteenth or fifteenth centuries, when the accumulation of books rendered them necessary, and those which are found in connection with old foundations will always prove to have been added later. It is said, however, that Gozbert, abbot of St Gall in the ninth century, who founded the library there by collecting what was then the large number of four hundred books, allotted them a special room over the scriptorium. But as a rule the books were kept in the church, and then, as the number increased, in the cloisters. The cloister was the common living-room of the monks, where they read and studied, and carried out most of their daily duties. The books were either stored in presses, though no such press remains to show us upon what pattern they were built, or in recesses in the wall, probably closed by doors. Two of these recesses may be seen in the cloisters at Worcester. In Cistercian houses, says Mr J. W. Clark, to whose Rede Lecture (1894) I am indebted for these details, this recess developed "into a small square room without a window, and but little larger than an ordinary cupboard. In the plans of Clairvaux and Kirkstall this room is placed between the chapter-house and the transept of the church; and similar rooms, in similar situations, have been found at Fountains, Beaulieu, Tintern, Netley, etc." The books were placed on shelves round the walls. When the cloister windows came to be glazed, so as to afford better protection from the weather for the persons and things within the cloister, they were occasionally decorated with allusions to the authors of the books in the adjacent presses. Sometimes _carrells_ were set up in the cloister, a carrell being a sort of pew, in which study could be conducted with more privacy than in the open cloister. The carrell was placed so that it was closed at one end by one of the cloister windows and remained open at the other. Examples still survive at Gloucester.