they contain gates, one or two portcullises, holes for stockades of timber, and loops raking the passage. Overhanging the arch at each end are funnels for pouring down hot matter upon the assailants, and above are ovens and flues for heating it. The Constable's gate, at Dover, is very early Edwardian; the gate of Caernarvon, 1283, and that of Lancaster, half a century later, are fine examples, and both the latter have statues over the gateway.
The draw-bridge dropped from the front of the gate; when the ditch was broad, a pier was erected in it, and the space spanned by two bridges, as at Holt and Caerphilly. The barbican was an outwork, or tête du pont, on the outside the counterscarp of the ditch. It seems to have been commonly of timber, so that when deserted, as it was intended to be, at a certain period of the siege, it might be burnt, and thus afford no cover to the assailants. The barbican of the tower of London is of stone, and evidently intended to be defended throughout a siege. There is a very complete stone barbican at Chepstow, Another description of barbican was attached to gates, viz., a narrow passage between walls in advance of the main gate, with an outer gate of entrance, as at Warwick and the Bars at York.
The posterns were either small doors in the wall, or if for cavalry were provided with smaller gatehouses and drawbridges.
The ditch was usually wet. At Caerphilly, Kenilworth, Berkhampstead, and Framlingham, a lake was formed by damming up the outlet of a meadow.
The top of the wall was defended by a parapet, notched into a battlement; each notch is an embrasure, and the intermediate piece of wall is a merlon. The coping of the merlon sometimes bears stone figures, as of armed men at Chepstow and Alnwick, at Caernarvon of eagles. Sometimes the merlon is pierced by a cruciform loop, terminating in four round holes or oillets.
In many cases a bold corbel-table is thrown out from the wall, and the parapet placed upon it, so as to leave an open space between the back of the parapet and the face of the wall. This space is divided by the corbels into holes called machicolations, which overlook the outside of the wall, as at Hexham and Warwick, or later at Raglan, and later still at Thornbury. If the parapet be not advanced by more than its own thickness, of course no hole is formed; this is called a false machicola-
