ROUND TOWERS  . A peculiar class of round tower exists throughout Ireland; about one hundred and twenty examples once existed; most of these are ruined, but eighteen or twenty are almost perfect . These towers were built either near or adjoining a church; they are of various dates, from perhaps the 8th to the 13th century; though varying in size and detail, they have many characteristics common to all . They are built with walls slightly battering inwards, so that the tower tapers towards the top . The lower part is formed of solid masonry, the one doorway being raised from 6 to 20 ft. above the ground, and so only accessible by means of a ladder . The towers within are divided into several storeys by two or more floors, usually of wood, but in some cases, as at Keneith, of stone slightly arched . The access from floor to floor was by ladders . The windows, which are always high up, are single lights, mostly arched or with a flat stone lintel . In some of the oldest towers they have triangular tops, formed by two stones leaning together . One peculiarity of the door and window openings in the Irish round towers is that the jambs are frequently set sloping, so that the opening grows narrower towards the top, as in the temples of . ancient Egypt . The later examples of these towers, dating from the 12th and 13th centuries, are often decorated with chevron, billet and other Norman enrichments round the jambs and arches . The roof is of stone, usually conical in shape, and some of the later towers are crowned by a circle of battlements .

The height of the round towers varies from about 6o to 132 ft.; that at Kilcullen was the highest . The masonry differs according to its date, the oldest examples being built of almost uncut

rubble work, and the later ones of neatly jointed ashlar . Much has been written as to the use of these towers, and the most conflicting theories as to their origin have been propounded . It is fairly certain, however, that they were constructed by Christian builders, both from the fact that they always are or once were near a church, and also because crosses and other Christian emblems frequently occur among the sculptured decorations of their doors and windows . Their original purpose was probably for places of refuge, for which the solid base and the door high above the ground seem specially adapted . They may also have been watch-towers, and in later times often contained bells . Their circular form was probably for the sake of strength, angles which could be attacked by a battering ram being thus avoided, and also because no quoins or dressed stones were needed, except for the openings—an important point at a time when tools for working stone were scarce and imperfect . Both these reasons may also account for the Norman round towers which are so common at the west end of churches in Norfolk, Suffolk and Essex, though these have little resemblance to those of Ireland except in the use of a circular plan . One example exactly like those of Ireland exists in the Isle of Man, within the precincts of Peel Castle adjacent to the cathedral of St German; it was probably the work of Irish builders . There are also three in Scotland, viz. at Egilshay in Orkney, and at Abernethy and Brechin . Round towers wider and lower in proportion than those of Ireland appear to have been built by many prehistoric races in different parts of Europe . The towers of this class in Scotland are called "brochs "; they average about 5o ft. high and 30 ft. in internal diameter .

Their walls, which are usually about 15 ft. thick at the bottom, are built hollow, of rubble masonry, with

series of passages one over the other running all round the tower . As in the Irish towers, the entrance is placed at some distance from the ground; and the whole structure is designed as a stronghold . The brochs appear. to have been the work of a pre-Christian Celtic race . Many objects in bronze and iron and fragments of hand-made pottery have been found in and near these towers, all bearing witness of a very early date . (See Anderson, Scotland in Pagan Times, 1883, and Scotland in Early Christian Times, 1881.) The nuraghi of Sardinia are described in the article on that island . During the 6th century church towers at and near Ravenna were usually built round in plan, and not unlike 'those of Ireland in their proportions . The finest existing example is that which stands by the church of S . Apollinare in Classe, the old port of the city of Ravenna (see BASILICA, fig . 8) . It is of brick, divided into nine storeys, with single-light windows below, three-light windows in the upper storeys, and two-lights in the intermediate ones . The most magnificent example of a round tower is the well-known leaning tower of Pisa, begun in the year 1174 . It is richly decorated with tiers of open marble arcades, supported on free columns .

The circular plan was much used by Moslem races for their minarets . The finest of these is the 13th-century minar of Kutb at Old

Delhi, built of limestone with bands of marble . It is richly fluted on plan, and when complete was at least 250 ft. high . The best account of the Irish round towers is that given by Petrie in his Ecclesiastical Architecture of Ireland (Dublin, 1845) . See also Keane, Towers and Temples of Ancient Ireland (Dublin, 185o) ; Brash, Ecclesiastical Architecture of Ireland (Dublin, 1875) ; and Stokes, Early Architecture in Ireland (Dublin, 1878) . (J . H .