The early monastic establishments had in their buildings none of the features found in the monasteries of the great Orders of a later period. No remains are found at Glendalough, or elsewhere in Ireland, of great houses, like those of the twelfth and following centuries, for the accommodation of large numbers. The abbot and other members of the community had each his own cell, with such buildings as were needed for guest-house, kitchen, and the like. These were, no doubt, of a primitive type and perishable material, as all traces of such structures have long since disappeared. A marked peculiarity of the churches in these places is their small size. It seems that as accommodation was required, additional small churches were built, and hence the many spots in Ireland noted for their collection of such buildings. A few structures known as ‘Houses,’ of which St. Kevin’s, already described, is the best-known example, are stone-roofed and vaulted, and seem to have combined the purpose of an ordinary dwelling-house with that of an oratory, and are thought to have been the residence of the abbot. The church on Friar’s Island, Killaloe, is another and early example, showing the transitional stage from the false to the true arch. The chancel measures 10½ feet by 6½ internally, and the walls are 3 feet thick; a very low chamber exists beneath the stone roof. The principle introduced in the barrel vaulting of these buildings was to lighten the weight of the heavy stone roof. A space was thus formed between it and the upper floor of the vaulting, which was turned to domestic use the more readily when divided by walls. The stone roofs possess no principle of the arch; they are built of rectangular slabs of dressed stones, well fitted for weather purposes, the top being finished with angular coping-stones. * * * * * [Illustration: St. Columba’s House, at Kells, Co. Meath.]