138 JOURNEY FROM numerous quadrangular buildings which are scattered in all directions over the Syrtis, in passing from Sooleb to Bengazi. These structures may be said to commence at Mahad Hassan ; but they assume at Zaffran the appearance of regular forts, and may there be considered as the commencement ,of a chain of fortified posts extending itself through the whole of the Syrtis*. They usually occupy the higher grounds, although some of them are situated in the plains, and are generally so placed as to have been originally seen from each other. Indeed no opportunity appears to have been neglected by the ancients of securing the advantages of pasturage and water which occur in the regions of the Syrtis ; wherever these exist we find fortresses erected, or regular stations established, which would materially contribute to facihtate the march of troops and to prevent at the same time the predatory incursions of the Arabs and the establishment of their tribes in these desirable positions.

If it be considered necessary to fix the sight of the roTo? A<r«5 at the first place where remains of ancient building are found, after the lake which is laid down by Strabo, we must place it at Mahad Hassan ; but if it must be identified with the port mentioned with it, which does not seem, indeed, to be necessary, we are then obhged to fix it at the first place where a port is to be met with, after the termination of the marsh, and this wiU bring us to Mersa Zaffranf .

* Buildings of the same nature are also found in the Cyrenaica. t Aspis is laid down in Ptolemy on the western side of the gulf, at about sixty miles within the promontory of Triaeorium ; but this distance would only bring us within nine miles of J aireed, and we have already stated that Mahad Hassan is the first place in the