The bells used in the Celtic Church seem to have belonged exclusively to the class of portable bells rung by hand. During the earlier period of Christianity in Ireland, when the monks lived together in small isolated communities, bells which were intended to carry sound to a great distance would be unnecessary, so that the absence of belfries in connection with the primitive dry-built stone oratories of the sixth and seventh centuries is easily explained. When, however, at a later period, the congregations became larger and more widely scattered, the lofty tower served a useful purpose in greatly increasing the area over which the sound of the bell could be heard. [385] Didron’s _Annales Archéologiques_, vol. vi., p. 315. [386] F. R. Fowke’s _Bayeux Tapestry_, pl. 31. The commencement of the building of belfries in Ireland coincides with the introduction of Lombardo-Byzantine architecture into that country, and the Irish round tower is obviously nothing more than a local variety of the Italian campanile. The Viking invasions at the same time gave an additional impetus to the erection of structures which could be used not only for ecclesiastical purposes, but also as watch-towers to detect the approach of the enemy, as bell-towers to alarm the neighbourhood, and as towers of defence to secure the lives and property of the congregation. The fact that the Irish round towers are called by the name of _cloiccthec_, or bell-house, in the ancient annals is sufficient proof they were used as belfries, but it does not appear to be known whether the bells were rung by swinging in the hand or fixed to a framework and swung on pivots. At any rate, no Irish bells of this period (A.D. 800 to 1000) have survived except the portable hand-bells. If any mechanical appliance was employed for bell-ringing in the Irish round towers it was probably constructed by fixing an ordinary hand-bell to a horizontal axle-bar of wood or iron, working in two bearings, and swung backwards and forwards by means of a rocking lever with a rope attached to it, as is done in many village churches at the present day. The large, heavy metal bells made specially with a view to being fixed in a tower and rung by a grooved wheel and cord belong to a much later period, after the Norman Conquest, when the art of making castings in bronze of great size had been learnt. The portable bell of the early Celtic Church is merely an ordinary cattle bell,[387] such as would, no doubt, be common in Pagan times, adapted to ecclesiastical purposes and slightly modified to suit the requirements of the monks. It differs hardly at all, except as regards size, from the common sheep-bell still to be found in many parts of England. Dr. Joseph Anderson tersely sums up the peculiarities of the Celtic ecclesiastical bell, as regards its material, manufacture, form, and size, in his _Scotland in Early Christian Times_ (first series), p. 183, somewhat as follows:—