Page:The age of Justinian and Theodora (Volume 1).djvu/57

 Bosphorus between Europe and Asia and finishing our circuit in the upper reaches of the Golden Horn. The single south wall, rising from the brink of the sea, is similar to that of Anthemius, and the towers exhibit the same diversity of form. Courses of rough stones immersed in the water lie along its base and form a kind of primitive breakwater, which saves its foundations from being sapped by the waves in tempestuous weather. These are said to have been quarried from the tops of the hills during the process of levelling the ground for the extension of the city, and then, at the suggestion of Constantine, sent rolling down the slopes until they became lodged in their present position.

Several gates in this wall give access to the water, but they possess no architectural distinction. Westerly is the Porta Psamathia or Sand-gate, so called because an area of new ground has been formed here by silting up of sand outside the wall. Near the opposite extremity is the Porta Ferrea or Iron-gate, thus designated from the unstable beach having been guarded by rails of iron to enable it to sustain the ponderous burdens imported by Constantine. Towards the centre of this shore is situated the Gate of St. Aemilian, named from its proximity to a church sacred to that martyr.