The somewhat dry disquisition just inflicted upon the unsuspecting reader is necessary in order to place him in a position to fully understand the mechanism of the typical Celtic brooch, the leading characteristics of which are that the ring has a break in its continuity (whence the name “penannular”), and that the length of the pin considerably exceeds the diameter of the ring. The object of the break in the continuity of the ring is that it enables the spring-catch to be dispensed with, the method of fixing the brooch in the dress being as follows: First, the long pin is inserted in the fabric at two points close together, in such a manner that the apex goes right through it and appears again above the surface; the pin is then forced through the break, and the ring is given a turn through a right angle in the plane of the fabric, thus fixing the brooch by the friction produced by the drag of the weight of the garment on the pin. We are now brought face to face with the question as to how the Celtic penannular brooch was worn. This can not only be conjecturally determined by an examination of the specimens to be found in museums, but fortunately can be settled beyond a shadow of a doubt in two ways, each of which confirms the other. First, there are at least two contemporary representations of persons actually wearing a penannular brooch (one on a cross at Monasterboice, Co. Louth, and the other on a cross at Kells, Co. Meath, in Ireland); and this ancient form of fibula has survived, and is in use at the present time in Algeria and elsewhere. The example at Monasterboice[417] is on the bottom panel of the side of the shaft of the cross of Muiredach (or Murdoch), which was erected in A.D. 924. The scene represented on the panel has been conjectured by the late Prof. J. O. Westwood, from its similarity to a miniature in the Book of Kells at Trinity College, Dublin, to be intended for Christ seized by the Jews. If this be so, the central figure is our Lord, and on each side is a soldier armed with a drawn sword. The sculpture is in good preservation, considering its great age, and the details of the costume, which are very elaborate, can be made out fairly well. Our Lord wears a sort of cloak with a penannular brooch fixed on His right shoulder. The split in the ring of the brooch faces downwards, and the pin is inclined upwards at an angle of about 30 degrees to the horizontal, the point being outwards. Probably the heavy head of the pin is placed downwards because its weight would always tend to bring it to this position, as the one of most stable equilibrium, but it may also have been to avoid injury from the point of the long pin. [417] _Illustrated Archæologist_ for 1893, p. 164. [Illustration: BISKRA WOMAN WEARING A PAIR OF PENANNULAR BROOCHES, THE ENDS OF THE PINS POINTING UPWARDS]