The provision of more than one bailey, as at Clun (43), where two small baileys, separated by ditches, cover the south and west sides of the mount, was due, partly to the irregular nature of the site, and partly to the need for the multiplication of defences. Such an arrangement, inconvenient in time of peace, would be a considerable advantage in case of siege, when each bailey would provide a separate difficulty to the assailants, and a separate rallying point to the defenders. At Builth (50), where the whole area of the castle earthworks is small, and the ditches of mount and bailey are of considerable strength, the main bailey is a narrow segmental platform covering the south side of the mount. On the west side of the mount is a smaller and narrower platform, between which and the main bailey is a broad ditch, forming a cross-cut or traverse between the ditches of the mount and bailey. As the enclosure is very nearly circular, with the mount north-west of the centre, this second platform is somewhat squeezed into the space, and the ditch between it and the counterscarp which runs continuously round both mount and bailey is very narrow. In the more usual instances, where the mount and its ditch form a regular circle, which intersects with the bailey and its ditch, a secondary platform, as has been noted, occurs outside the line of both ditches, and is surrounded by a ditch of its own, communicating with both. This is the case with the very symmetrical example of a mount-and-bailey castle at Mexborough, at Lilbourne in Northants, Hallaton in Leicestershire (51), and other cases. Here the secondary platform is an excrescence on one side of the meeting of the two circles. Such platforms were mere outworks where additional defence was necessary; it is possible that on them stone-throwing engines might be planted by the defenders, as the narrowness of the ditch would at these points bring the assailants more nearly within range than at any other point within the enclosure. Such engines would encumber the larger bailey, which would necessarily be kept as clear as possible for the operations of the main body of the garrison. [Illustration: Hallaton; Plan]