Some doubt has arisen as to how the octagon was originally approached from the main land. This doubt is caused by the presence of a demi-pier of masonry projecting from the west bank a few yards from its north end, and therefore opposite to the octagon. It is therefore supposed that the causeway from the north bank is an addition, and that another causeway, or some kind of communication, was laid from the west bank to the octagon, a much greater distance, nearly thrice as far. No doubt a similar half-pier on the south bank indicates a communication thence with the lesser gateway, but here there seems no reason whatever for the suggested lengthening and bend in the approach. On the whole, for whatever purpose the western pier may have been intended, the evidence is in favour of the approach having always been along the present line. Neither the north nor the west bank is commanded seriously by higher ground. That to the north rises, no doubt, but scarcely so as to give any great advantage to archers posted to annoy those entering the castle, and certainly no greater advantage than could be gained from the rising ground to the west. Possibly the pier was intended for the mooring and protection of the boats employed on that side of the moat. A road, still traceable, led up to this demi-pier. This double outwork in the moat is peculiar, it is supposed, to Bodiham. At Ledes, indeed, there are two barbicans, but they are not exactly in the moat, but upon the bank, and are deeply intrenched, so as to carry the water round them. At Caerphilly, there is a single large isolated pier in the centre of the moat, now dry, which pier was connected by drawbridges with the great gate and the counterscarp, and may be likened to the octagon in the present instance. BORTHWICK TOWER, IN MIDLOTHIAN. Borthwick has been selected and is included in these examples as a noble specimen of military architecture, and the finest extant specimen of the Peel tower so celebrated upon the Scottish border; meaning by a “Peel” a stronghold of which the tower is the only considerable work, and which stands within a walled base-court or barmkin of moderate area. Here, indeed, the dimensions of the tower are those of a Norman keep, and the court, though small, is guarded by bastion towers of large diameter, but still the tower is itself the fortress, and was obviously the residence of the lord and his family, not only during a siege, but at all times. Such fortresses as Lochleven and Urquhart on Loch Ness, though far inferior to Borthwick in strength of masonry and grandeur, are nevertheless castles, whereas Borthwick is a Peel. [Illustration: SECTION A B, LOOKING WESTWARD.]